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1/*
2 * TI TRF7970a RFID/NFC Transceiver Driver
3 *
4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5 *
6 * Author: Erick Macias <emacias@ti.com>
7 * Author: Felipe Balbi <balbi@ti.com>
8 * Author: Mark A. Greer <mgreer@animalcreek.com>
9 *
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 of
12 * the License as published by the Free Software Foundation.
13 */
14
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/netdevice.h>
18#include <linux/interrupt.h>
19#include <linux/nfc.h>
20#include <linux/skbuff.h>
21#include <linux/delay.h>
22#include <linux/gpio.h>
23#include <linux/of.h>
24#include <linux/of_gpio.h>
25#include <linux/spi/spi.h>
26#include <linux/regulator/consumer.h>
27
28#include <net/nfc/nfc.h>
29#include <net/nfc/digital.h>
30
31/* There are 3 ways the host can communicate with the trf7970a:
32 * parallel mode, SPI with Slave Select (SS) mode, and SPI without
33 * SS mode. The driver only supports the two SPI modes.
34 *
35 * The trf7970a is very timing sensitive and the VIN, EN2, and EN
36 * pins must asserted in that order and with specific delays in between.
37 * The delays used in the driver were provided by TI and have been
38 * confirmed to work with this driver.
39 *
40 * Timeouts are implemented using the delayed workqueue kernel facility.
41 * Timeouts are required so things don't hang when there is no response
42 * from the trf7970a (or tag). Using this mechanism creates a race with
43 * interrupts, however. That is, an interrupt and a timeout could occur
44 * closely enough together that one is blocked by the mutex while the other
45 * executes. When the timeout handler executes first and blocks the
46 * interrupt handler, it will eventually set the state to IDLE so the
47 * interrupt handler will check the state and exit with no harm done.
48 * When the interrupt handler executes first and blocks the timeout handler,
49 * the cancel_delayed_work() call will know that it didn't cancel the
50 * work item (i.e., timeout) and will return zero. That return code is
51 * used by the timer handler to indicate that it should ignore the timeout
52 * once its unblocked.
53 *
54 * Aborting an active command isn't as simple as it seems because the only
55 * way to abort a command that's already been sent to the tag is so turn
56 * off power to the tag. If we do that, though, we'd have to go through
57 * the entire anticollision procedure again but the digital layer doesn't
58 * support that. So, if an abort is received before trf7970a_in_send_cmd()
59 * has sent the command to the tag, it simply returns -ECANCELED. If the
60 * command has already been sent to the tag, then the driver continues
61 * normally and recieves the response data (or error) but just before
62 * sending the data upstream, it frees the rx_skb and sends -ECANCELED
63 * upstream instead. If the command failed, that error will be sent
64 * upstream.
65 *
66 * When recieving data from a tag and the interrupt status register has
67 * only the SRX bit set, it means that all of the data has been received
68 * (once what's in the fifo has been read). However, depending on timing
69 * an interrupt status with only the SRX bit set may not be recived. In
70 * those cases, the timeout mechanism is used to wait 5 ms in case more
71 * data arrives. After 5 ms, it is assumed that all of the data has been
72 * received and the accumulated rx data is sent upstream. The
73 * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
74 * (i.e., it indicates that some data has been received but we're not sure
75 * if there is more coming so a timeout in this state means all data has
76 * been received and there isn't an error). The delay is 5 ms since delays
77 * over 2 ms have been observed during testing (a little extra just in case).
78 *
79 * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
80 * Having only 4 bits in the FIFO won't normally generate an interrupt so
81 * driver enables the '4_bit_RX' bit of the Special Functions register 1
82 * to cause an interrupt in that case. Leaving that bit for a read command
83 * messes up the data returned so it is only enabled when the framing is
84 * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
85 * Unfortunately, that means that the driver has to peek into tx frames
86 * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by
87 * the trf7970a_per_cmd_config() routine.
88 *
89 * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
90 * frequencies and whether to use low or high data rates in the flags byte
91 * of the frame. This means that the driver has to peek at all 15693 frames
92 * to determine what speed to set the communication to. In addition, write
93 * and lock commands use the OPTION flag to indicate that an EOF must be
94 * sent to the tag before it will send its response. So the driver has to
95 * examine all frames for that reason too.
96 *
97 * It is unclear how long to wait before sending the EOF. According to the
98 * Note under Table 1-1 in section 1.6 of
99 * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
100 * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
101 * enough. For this reason, the driver waits 20 ms which seems to work
102 * reliably.
103 */
104
105#define TRF7970A_SUPPORTED_PROTOCOLS \
106 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
107 NFC_PROTO_ISO15693_MASK)
108
109/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
110 * on what the current framing is, the address of the TX length byte 1
111 * register (0x1d), and the 2 byte length of the data to be transmitted.
112 * That totals 5 bytes.
113 */
114#define TRF7970A_TX_SKB_HEADROOM 5
115
116#define TRF7970A_RX_SKB_ALLOC_SIZE 256
117
118#define TRF7970A_FIFO_SIZE 128
119
120/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
121#define TRF7970A_TX_MAX (4096 - 1)
122
123#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 5
124#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 3
125#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 20
126
127/* Quirks */
128/* Erratum: When reading IRQ Status register on trf7970a, we must issue a
129 * read continuous command for IRQ Status and Collision Position registers.
130 */
131#define TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA BIT(0)
132
133/* Direct commands */
134#define TRF7970A_CMD_IDLE 0x00
135#define TRF7970A_CMD_SOFT_INIT 0x03
136#define TRF7970A_CMD_RF_COLLISION 0x04
137#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05
138#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06
139#define TRF7970A_CMD_FIFO_RESET 0x0f
140#define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10
141#define TRF7970A_CMD_TRANSMIT 0x11
142#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12
143#define TRF7970A_CMD_DELAY_TRANSMIT 0x13
144#define TRF7970A_CMD_EOF 0x14
145#define TRF7970A_CMD_CLOSE_SLOT 0x15
146#define TRF7970A_CMD_BLOCK_RX 0x16
147#define TRF7970A_CMD_ENABLE_RX 0x17
148#define TRF7970A_CMD_TEST_EXT_RF 0x18
149#define TRF7970A_CMD_TEST_INT_RF 0x19
150#define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a
151
152/* Bits determining whether its a direct command or register R/W,
153 * whether to use a continuous SPI transaction or not, and the actual
154 * direct cmd opcode or regster address.
155 */
156#define TRF7970A_CMD_BIT_CTRL BIT(7)
157#define TRF7970A_CMD_BIT_RW BIT(6)
158#define TRF7970A_CMD_BIT_CONTINUOUS BIT(5)
159#define TRF7970A_CMD_BIT_OPCODE(opcode) ((opcode) & 0x1f)
160
161/* Registers addresses */
162#define TRF7970A_CHIP_STATUS_CTRL 0x00
163#define TRF7970A_ISO_CTRL 0x01
164#define TRF7970A_ISO14443B_TX_OPTIONS 0x02
165#define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
166#define TRF7970A_TX_TIMER_SETTING_H_BYTE 0x04
167#define TRF7970A_TX_TIMER_SETTING_L_BYTE 0x05
168#define TRF7970A_TX_PULSE_LENGTH_CTRL 0x06
169#define TRF7970A_RX_NO_RESPONSE_WAIT 0x07
170#define TRF7970A_RX_WAIT_TIME 0x08
171#define TRF7970A_MODULATOR_SYS_CLK_CTRL 0x09
172#define TRF7970A_RX_SPECIAL_SETTINGS 0x0a
173#define TRF7970A_REG_IO_CTRL 0x0b
174#define TRF7970A_IRQ_STATUS 0x0c
175#define TRF7970A_COLLISION_IRQ_MASK 0x0d
176#define TRF7970A_COLLISION_POSITION 0x0e
177#define TRF7970A_RSSI_OSC_STATUS 0x0f
178#define TRF7970A_SPECIAL_FCN_REG1 0x10
179#define TRF7970A_SPECIAL_FCN_REG2 0x11
180#define TRF7970A_RAM1 0x12
181#define TRF7970A_RAM2 0x13
182#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS 0x14
183#define TRF7970A_NFC_LOW_FIELD_LEVEL 0x16
184#define TRF7970A_NFCID1 0x17
185#define TRF7970A_NFC_TARGET_LEVEL 0x18
186#define TRF79070A_NFC_TARGET_PROTOCOL 0x19
187#define TRF7970A_TEST_REGISTER1 0x1a
188#define TRF7970A_TEST_REGISTER2 0x1b
189#define TRF7970A_FIFO_STATUS 0x1c
190#define TRF7970A_TX_LENGTH_BYTE1 0x1d
191#define TRF7970A_TX_LENGTH_BYTE2 0x1e
192#define TRF7970A_FIFO_IO_REGISTER 0x1f
193
194/* Chip Status Control Register Bits */
195#define TRF7970A_CHIP_STATUS_VRS5_3 BIT(0)
196#define TRF7970A_CHIP_STATUS_REC_ON BIT(1)
197#define TRF7970A_CHIP_STATUS_AGC_ON BIT(2)
198#define TRF7970A_CHIP_STATUS_PM_ON BIT(3)
199#define TRF7970A_CHIP_STATUS_RF_PWR BIT(4)
200#define TRF7970A_CHIP_STATUS_RF_ON BIT(5)
201#define TRF7970A_CHIP_STATUS_DIRECT BIT(6)
202#define TRF7970A_CHIP_STATUS_STBY BIT(7)
203
204/* ISO Control Register Bits */
205#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662 0x00
206#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662 0x01
207#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648 0x02
208#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
209#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a 0x04
210#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667 0x05
211#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669 0x06
212#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
213#define TRF7970A_ISO_CTRL_14443A_106 0x08
214#define TRF7970A_ISO_CTRL_14443A_212 0x09
215#define TRF7970A_ISO_CTRL_14443A_424 0x0a
216#define TRF7970A_ISO_CTRL_14443A_848 0x0b
217#define TRF7970A_ISO_CTRL_14443B_106 0x0c
218#define TRF7970A_ISO_CTRL_14443B_212 0x0d
219#define TRF7970A_ISO_CTRL_14443B_424 0x0e
220#define TRF7970A_ISO_CTRL_14443B_848 0x0f
221#define TRF7970A_ISO_CTRL_FELICA_212 0x1a
222#define TRF7970A_ISO_CTRL_FELICA_424 0x1b
223#define TRF7970A_ISO_CTRL_RFID BIT(5)
224#define TRF7970A_ISO_CTRL_DIR_MODE BIT(6)
225#define TRF7970A_ISO_CTRL_RX_CRC_N BIT(7) /* true == No CRC */
226
227#define TRF7970A_ISO_CTRL_RFID_SPEED_MASK 0x1f
228
229/* Modulator and SYS_CLK Control Register Bits */
230#define TRF7970A_MODULATOR_DEPTH(n) ((n) & 0x7)
231#define TRF7970A_MODULATOR_DEPTH_ASK10 (TRF7970A_MODULATOR_DEPTH(0))
232#define TRF7970A_MODULATOR_DEPTH_OOK (TRF7970A_MODULATOR_DEPTH(1))
233#define TRF7970A_MODULATOR_DEPTH_ASK7 (TRF7970A_MODULATOR_DEPTH(2))
234#define TRF7970A_MODULATOR_DEPTH_ASK8_5 (TRF7970A_MODULATOR_DEPTH(3))
235#define TRF7970A_MODULATOR_DEPTH_ASK13 (TRF7970A_MODULATOR_DEPTH(4))
236#define TRF7970A_MODULATOR_DEPTH_ASK16 (TRF7970A_MODULATOR_DEPTH(5))
237#define TRF7970A_MODULATOR_DEPTH_ASK22 (TRF7970A_MODULATOR_DEPTH(6))
238#define TRF7970A_MODULATOR_DEPTH_ASK30 (TRF7970A_MODULATOR_DEPTH(7))
239#define TRF7970A_MODULATOR_EN_ANA BIT(3)
240#define TRF7970A_MODULATOR_CLK(n) (((n) & 0x3) << 4)
241#define TRF7970A_MODULATOR_CLK_DISABLED (TRF7970A_MODULATOR_CLK(0))
242#define TRF7970A_MODULATOR_CLK_3_6 (TRF7970A_MODULATOR_CLK(1))
243#define TRF7970A_MODULATOR_CLK_6_13 (TRF7970A_MODULATOR_CLK(2))
244#define TRF7970A_MODULATOR_CLK_13_27 (TRF7970A_MODULATOR_CLK(3))
245#define TRF7970A_MODULATOR_EN_OOK BIT(6)
246#define TRF7970A_MODULATOR_27MHZ BIT(7)
247
248/* IRQ Status Register Bits */
249#define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
250#define TRF7970A_IRQ_STATUS_COL BIT(1)
251#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
252#define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
253#define TRF7970A_IRQ_STATUS_CRC_ERROR BIT(4)
254#define TRF7970A_IRQ_STATUS_FIFO BIT(5)
255#define TRF7970A_IRQ_STATUS_SRX BIT(6)
256#define TRF7970A_IRQ_STATUS_TX BIT(7)
257
258#define TRF7970A_IRQ_STATUS_ERROR \
259 (TRF7970A_IRQ_STATUS_COL | \
260 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR | \
261 TRF7970A_IRQ_STATUS_PARITY_ERROR | \
262 TRF7970A_IRQ_STATUS_CRC_ERROR)
263
264#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6 BIT(0)
265#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL BIT(1)
266#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX BIT(2)
267#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE BIT(3)
268#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US BIT(4)
269#define TRF7970A_SPECIAL_FCN_REG1_PAR43 BIT(5)
270
271#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124 (0x0 << 2)
272#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120 (0x1 << 2)
273#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112 (0x2 << 2)
274#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 (0x3 << 2)
275#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4 0x0
276#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8 0x1
277#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16 0x2
278#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32 0x3
279
280#define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7)
281
282/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
283#define NFC_T2T_CMD_READ 0x30
284
285/* ISO 15693 commands codes */
286#define ISO15693_CMD_INVENTORY 0x01
287#define ISO15693_CMD_READ_SINGLE_BLOCK 0x20
288#define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21
289#define ISO15693_CMD_LOCK_BLOCK 0x22
290#define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23
291#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24
292#define ISO15693_CMD_SELECT 0x25
293#define ISO15693_CMD_RESET_TO_READY 0x26
294#define ISO15693_CMD_WRITE_AFI 0x27
295#define ISO15693_CMD_LOCK_AFI 0x28
296#define ISO15693_CMD_WRITE_DSFID 0x29
297#define ISO15693_CMD_LOCK_DSFID 0x2a
298#define ISO15693_CMD_GET_SYSTEM_INFO 0x2b
299#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
300
301/* ISO 15693 request and response flags */
302#define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0)
303#define ISO15693_REQ_FLAG_DATA_RATE BIT(1)
304#define ISO15693_REQ_FLAG_INVENTORY BIT(2)
305#define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3)
306#define ISO15693_REQ_FLAG_SELECT BIT(4)
307#define ISO15693_REQ_FLAG_AFI BIT(4)
308#define ISO15693_REQ_FLAG_ADDRESS BIT(5)
309#define ISO15693_REQ_FLAG_NB_SLOTS BIT(5)
310#define ISO15693_REQ_FLAG_OPTION BIT(6)
311
312#define ISO15693_REQ_FLAG_SPEED_MASK \
313 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
314
315enum trf7970a_state {
316 TRF7970A_ST_OFF,
317 TRF7970A_ST_IDLE,
318 TRF7970A_ST_IDLE_RX_BLOCKED,
319 TRF7970A_ST_WAIT_FOR_TX_FIFO,
320 TRF7970A_ST_WAIT_FOR_RX_DATA,
321 TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
322 TRF7970A_ST_WAIT_TO_ISSUE_EOF,
323 TRF7970A_ST_MAX
324};
325
326struct trf7970a {
327 enum trf7970a_state state;
328 struct device *dev;
329 struct spi_device *spi;
330 struct regulator *regulator;
331 struct nfc_digital_dev *ddev;
332 u32 quirks;
333 bool powering_up;
334 bool aborting;
335 struct sk_buff *tx_skb;
336 struct sk_buff *rx_skb;
337 nfc_digital_cmd_complete_t cb;
338 void *cb_arg;
339 u8 iso_ctrl;
340 u8 special_fcn_reg1;
341 int technology;
342 int framing;
343 u8 tx_cmd;
344 bool issue_eof;
345 int en2_gpio;
346 int en_gpio;
347 struct mutex lock;
348 unsigned int timeout;
349 bool ignore_timeout;
350 struct delayed_work timeout_work;
351};
352
353
354static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
355{
356 u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
357 int ret;
358
359 dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
360
361 ret = spi_write(trf->spi, &cmd, 1);
362 if (ret)
363 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
364 ret);
365 return ret;
366}
367
368static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
369{
370 u8 addr = TRF7970A_CMD_BIT_RW | reg;
371 int ret;
372
373 ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
374 if (ret)
375 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
376 ret);
377
378 dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
379
380 return ret;
381}
382
383static int trf7970a_read_cont(struct trf7970a *trf, u8 reg,
384 u8 *buf, size_t len)
385{
386 u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
387 int ret;
388
389 dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
390
391 ret = spi_write_then_read(trf->spi, &addr, 1, buf, len);
392 if (ret)
393 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
394 ret);
395 return ret;
396}
397
398static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
399{
400 u8 buf[2] = { reg, val };
401 int ret;
402
403 dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
404
405 ret = spi_write(trf->spi, buf, 2);
406 if (ret)
407 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
408 buf[0], buf[1], ret);
409
410 return ret;
411}
412
413static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
414{
415 int ret;
416 u8 buf[2];
417 u8 addr;
418
419 addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
420
421 if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA) {
422 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
423 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
424 } else {
425 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
426 }
427
428 if (ret)
429 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
430 __func__, ret);
431 else
432 *status = buf[0];
433
434 return ret;
435}
436
437static void trf7970a_send_upstream(struct trf7970a *trf)
438{
439 u8 rssi;
440
441 dev_kfree_skb_any(trf->tx_skb);
442 trf->tx_skb = NULL;
443
444 if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
445 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
446 16, 1, trf->rx_skb->data, trf->rx_skb->len,
447 false);
448
449 /* According to the manual it is "good form" to reset the fifo and
450 * read the RSSI levels & oscillator status register here. It doesn't
451 * explain why.
452 */
453 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
454 trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
455
456 trf->state = TRF7970A_ST_IDLE;
457
458 if (trf->aborting) {
459 dev_dbg(trf->dev, "Abort process complete\n");
460
461 if (!IS_ERR(trf->rx_skb)) {
462 kfree_skb(trf->rx_skb);
463 trf->rx_skb = ERR_PTR(-ECANCELED);
464 }
465
466 trf->aborting = false;
467 }
468
469 trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
470
471 trf->rx_skb = NULL;
472}
473
474static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
475{
476 dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
477
478 kfree_skb(trf->rx_skb);
479 trf->rx_skb = ERR_PTR(errno);
480
481 trf7970a_send_upstream(trf);
482}
483
484static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
485 unsigned int len)
486{
487 unsigned int timeout;
488 int ret;
489
490 print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
491 16, 1, skb->data, len, false);
492
493 ret = spi_write(trf->spi, skb->data, len);
494 if (ret) {
495 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
496 ret);
497 return ret;
498 }
499
500 skb_pull(skb, len);
501
502 if (skb->len > 0) {
503 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
504 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
505 } else {
506 if (trf->issue_eof) {
507 trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
508 timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
509 } else {
510 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
511 timeout = trf->timeout;
512 }
513 }
514
515 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
516 trf->state);
517
518 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
519
520 return 0;
521}
522
523static void trf7970a_fill_fifo(struct trf7970a *trf)
524{
525 struct sk_buff *skb = trf->tx_skb;
526 unsigned int len;
527 int ret;
528 u8 fifo_bytes;
529
530 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
531 if (ret) {
532 trf7970a_send_err_upstream(trf, ret);
533 return;
534 }
535
536 dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
537
538 if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
539 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
540 fifo_bytes);
541 trf7970a_send_err_upstream(trf, -EIO);
542 return;
543 }
544
545 /* Calculate how much more data can be written to the fifo */
546 len = TRF7970A_FIFO_SIZE - fifo_bytes;
547 len = min(skb->len, len);
548
549 ret = trf7970a_transmit(trf, skb, len);
550 if (ret)
551 trf7970a_send_err_upstream(trf, ret);
552}
553
554static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
555{
556 struct sk_buff *skb = trf->rx_skb;
557 int ret;
558 u8 fifo_bytes;
559
560 if (status & TRF7970A_IRQ_STATUS_ERROR) {
561 trf7970a_send_err_upstream(trf, -EIO);
562 return;
563 }
564
565 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
566 if (ret) {
567 trf7970a_send_err_upstream(trf, ret);
568 return;
569 }
570
571 dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
572
573 if (!fifo_bytes)
574 goto no_rx_data;
575
576 if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
577 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
578 fifo_bytes);
579 trf7970a_send_err_upstream(trf, -EIO);
580 return;
581 }
582
583 if (fifo_bytes > skb_tailroom(skb)) {
584 skb = skb_copy_expand(skb, skb_headroom(skb),
585 max_t(int, fifo_bytes,
586 TRF7970A_RX_SKB_ALLOC_SIZE),
587 GFP_KERNEL);
588 if (!skb) {
589 trf7970a_send_err_upstream(trf, -ENOMEM);
590 return;
591 }
592
593 kfree_skb(trf->rx_skb);
594 trf->rx_skb = skb;
595 }
596
597 ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
598 skb_put(skb, fifo_bytes), fifo_bytes);
599 if (ret) {
600 trf7970a_send_err_upstream(trf, ret);
601 return;
602 }
603
604 /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
605 if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
606 (trf->special_fcn_reg1 ==
607 TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
608 skb->data[0] >>= 4;
609 status = TRF7970A_IRQ_STATUS_SRX;
610 } else {
611 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
612 }
613
614no_rx_data:
615 if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
616 trf7970a_send_upstream(trf);
617 return;
618 }
619
620 dev_dbg(trf->dev, "Setting timeout for %d ms\n",
621 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
622
623 schedule_delayed_work(&trf->timeout_work,
624 msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
625}
626
627static irqreturn_t trf7970a_irq(int irq, void *dev_id)
628{
629 struct trf7970a *trf = dev_id;
630 int ret;
631 u8 status;
632
633 mutex_lock(&trf->lock);
634
635 if (trf->state == TRF7970A_ST_OFF) {
636 mutex_unlock(&trf->lock);
637 return IRQ_NONE;
638 }
639
640 ret = trf7970a_read_irqstatus(trf, &status);
641 if (ret) {
642 mutex_unlock(&trf->lock);
643 return IRQ_NONE;
644 }
645
646 dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
647 status);
648
649 if (!status) {
650 mutex_unlock(&trf->lock);
651 return IRQ_NONE;
652 }
653
654 switch (trf->state) {
655 case TRF7970A_ST_IDLE:
656 case TRF7970A_ST_IDLE_RX_BLOCKED:
657 /* If getting interrupts caused by RF noise, turn off the
658 * receiver to avoid unnecessary interrupts. It will be
659 * turned back on in trf7970a_in_send_cmd() when the next
660 * command is issued.
661 */
662 if (status & TRF7970A_IRQ_STATUS_ERROR) {
663 trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
664 trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
665 }
666
667 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
668 break;
669 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
670 if (status & TRF7970A_IRQ_STATUS_TX) {
671 trf->ignore_timeout =
672 !cancel_delayed_work(&trf->timeout_work);
673 trf7970a_fill_fifo(trf);
674 } else {
675 trf7970a_send_err_upstream(trf, -EIO);
676 }
677 break;
678 case TRF7970A_ST_WAIT_FOR_RX_DATA:
679 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
680 if (status & TRF7970A_IRQ_STATUS_SRX) {
681 trf->ignore_timeout =
682 !cancel_delayed_work(&trf->timeout_work);
683 trf7970a_drain_fifo(trf, status);
684 } else if (!(status & TRF7970A_IRQ_STATUS_TX)) {
685 trf7970a_send_err_upstream(trf, -EIO);
686 }
687 break;
688 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
689 if (status != TRF7970A_IRQ_STATUS_TX)
690 trf7970a_send_err_upstream(trf, -EIO);
691 break;
692 default:
693 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
694 __func__, trf->state);
695 }
696
697 mutex_unlock(&trf->lock);
698 return IRQ_HANDLED;
699}
700
701static void trf7970a_issue_eof(struct trf7970a *trf)
702{
703 int ret;
704
705 dev_dbg(trf->dev, "Issuing EOF\n");
706
707 ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
708 if (ret)
709 trf7970a_send_err_upstream(trf, ret);
710
711 ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
712 if (ret)
713 trf7970a_send_err_upstream(trf, ret);
714
715 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
716
717 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
718 trf->timeout, trf->state);
719
720 schedule_delayed_work(&trf->timeout_work,
721 msecs_to_jiffies(trf->timeout));
722}
723
724static void trf7970a_timeout_work_handler(struct work_struct *work)
725{
726 struct trf7970a *trf = container_of(work, struct trf7970a,
727 timeout_work.work);
728
729 dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
730 trf->state, trf->ignore_timeout);
731
732 mutex_lock(&trf->lock);
733
734 if (trf->ignore_timeout)
735 trf->ignore_timeout = false;
736 else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
737 trf7970a_send_upstream(trf); /* No more rx data so send up */
738 else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
739 trf7970a_issue_eof(trf);
740 else
741 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
742
743 mutex_unlock(&trf->lock);
744}
745
746static int trf7970a_init(struct trf7970a *trf)
747{
748 int ret;
749
750 dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
751
752 ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
753 if (ret)
754 goto err_out;
755
756 ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
757 if (ret)
758 goto err_out;
759
760 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
761 TRF7970A_MODULATOR_DEPTH_OOK);
762 if (ret)
763 goto err_out;
764
765 ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
766 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
767 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
768 if (ret)
769 goto err_out;
770
771 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
772 if (ret)
773 goto err_out;
774
775 trf->special_fcn_reg1 = 0;
776
777 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
778 TRF7970A_CHIP_STATUS_RF_ON |
779 TRF7970A_CHIP_STATUS_VRS5_3);
780 if (ret)
781 goto err_out;
782
783 return 0;
784
785err_out:
786 dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
787 return ret;
788}
789
790static void trf7970a_switch_rf_off(struct trf7970a *trf)
791{
792 dev_dbg(trf->dev, "Switching rf off\n");
793
794 gpio_set_value(trf->en_gpio, 0);
795 gpio_set_value(trf->en2_gpio, 0);
796
797 trf->aborting = false;
798 trf->state = TRF7970A_ST_OFF;
799}
800
801static int trf7970a_switch_rf_on(struct trf7970a *trf)
802{
803 unsigned long delay;
804 int ret;
805
806 dev_dbg(trf->dev, "Switching rf on\n");
807
808 if (trf->powering_up)
809 usleep_range(5000, 6000);
810
811 gpio_set_value(trf->en2_gpio, 1);
812 usleep_range(1000, 2000);
813 gpio_set_value(trf->en_gpio, 1);
814
815 /* The delay between enabling the trf7970a and issuing the first
816 * command is significantly longer the very first time after powering
817 * up. Make sure the longer delay is only done the first time.
818 */
819 if (trf->powering_up) {
820 delay = 20000;
821 trf->powering_up = false;
822 } else {
823 delay = 5000;
824 }
825
826 usleep_range(delay, delay + 1000);
827
828 ret = trf7970a_init(trf);
829 if (ret)
830 trf7970a_switch_rf_off(trf);
831 else
832 trf->state = TRF7970A_ST_IDLE;
833
834 return ret;
835}
836
837static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
838{
839 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
840 int ret = 0;
841
842 dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
843
844 mutex_lock(&trf->lock);
845
846 if (on) {
847 switch (trf->state) {
848 case TRF7970A_ST_OFF:
849 ret = trf7970a_switch_rf_on(trf);
850 break;
851 case TRF7970A_ST_IDLE:
852 case TRF7970A_ST_IDLE_RX_BLOCKED:
853 break;
854 default:
855 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
856 __func__, trf->state, on);
857 trf7970a_switch_rf_off(trf);
858 }
859 } else {
860 switch (trf->state) {
861 case TRF7970A_ST_OFF:
862 break;
863 default:
864 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
865 __func__, trf->state, on);
866 /* FALLTHROUGH */
867 case TRF7970A_ST_IDLE:
868 case TRF7970A_ST_IDLE_RX_BLOCKED:
869 trf7970a_switch_rf_off(trf);
870 }
871 }
872
873 mutex_unlock(&trf->lock);
874 return ret;
875}
876
877static int trf7970a_config_rf_tech(struct trf7970a *trf, int tech)
878{
879 int ret = 0;
880
881 dev_dbg(trf->dev, "rf technology: %d\n", tech);
882
883 switch (tech) {
884 case NFC_DIGITAL_RF_TECH_106A:
885 trf->iso_ctrl = TRF7970A_ISO_CTRL_14443A_106;
886 break;
887 case NFC_DIGITAL_RF_TECH_ISO15693:
888 trf->iso_ctrl = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
889 break;
890 default:
891 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
892 return -EINVAL;
893 }
894
895 trf->technology = tech;
896
897 return ret;
898}
899
900static int trf7970a_config_framing(struct trf7970a *trf, int framing)
901{
902 dev_dbg(trf->dev, "framing: %d\n", framing);
903
904 switch (framing) {
905 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
906 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
907 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
908 trf->iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
909 break;
910 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
911 case NFC_DIGITAL_FRAMING_NFCA_T4T:
912 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
913 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
914 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
915 trf->iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
916 break;
917 case NFC_DIGITAL_FRAMING_NFCA_T2T:
918 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
919 trf->iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
920 break;
921 default:
922 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
923 return -EINVAL;
924 }
925
926 trf->framing = framing;
927
928 return trf7970a_write(trf, TRF7970A_ISO_CTRL, trf->iso_ctrl);
929}
930
931static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
932 int param)
933{
934 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
935 int ret = 0;
936
937 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
938
939 mutex_lock(&trf->lock);
940
941 if (trf->state == TRF7970A_ST_OFF) {
942 ret = trf7970a_switch_rf_on(trf);
943 if (ret)
944 goto err_out;
945 }
946
947 switch (type) {
948 case NFC_DIGITAL_CONFIG_RF_TECH:
949 ret = trf7970a_config_rf_tech(trf, param);
950 break;
951 case NFC_DIGITAL_CONFIG_FRAMING:
952 ret = trf7970a_config_framing(trf, param);
953 break;
954 default:
955 dev_dbg(trf->dev, "Unknown type: %d\n", type);
956 ret = -EINVAL;
957 }
958
959err_out:
960 mutex_unlock(&trf->lock);
961 return ret;
962}
963
964static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
965{
966 switch (cmd) {
967 case ISO15693_CMD_WRITE_SINGLE_BLOCK:
968 case ISO15693_CMD_LOCK_BLOCK:
969 case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
970 case ISO15693_CMD_WRITE_AFI:
971 case ISO15693_CMD_LOCK_AFI:
972 case ISO15693_CMD_WRITE_DSFID:
973 case ISO15693_CMD_LOCK_DSFID:
974 return 1;
975 break;
976 default:
977 return 0;
978 }
979}
980
981static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
982{
983 u8 *req = skb->data;
984 u8 special_fcn_reg1, iso_ctrl;
985 int ret;
986
987 trf->issue_eof = false;
988
989 /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
990 * special functions register 1 is cleared; otherwise, its a write or
991 * sector select command and '4_bit_RX' must be set.
992 *
993 * When issuing an ISO 15693 command, inspect the flags byte to see
994 * what speed to use. Also, remember if the OPTION flag is set on
995 * a Type 5 write or lock command so the driver will know that it
996 * has to send an EOF in order to get a response.
997 */
998 if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
999 (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1000 if (req[0] == NFC_T2T_CMD_READ)
1001 special_fcn_reg1 = 0;
1002 else
1003 special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1004
1005 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1006 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1007 special_fcn_reg1);
1008 if (ret)
1009 return ret;
1010
1011 trf->special_fcn_reg1 = special_fcn_reg1;
1012 }
1013 } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1014 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1015
1016 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1017 case 0x00:
1018 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1019 break;
1020 case ISO15693_REQ_FLAG_SUB_CARRIER:
1021 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1022 break;
1023 case ISO15693_REQ_FLAG_DATA_RATE:
1024 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1025 break;
1026 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1027 ISO15693_REQ_FLAG_DATA_RATE):
1028 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1029 break;
1030 }
1031
1032 if (iso_ctrl != trf->iso_ctrl) {
1033 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1034 if (ret)
1035 return ret;
1036
1037 trf->iso_ctrl = iso_ctrl;
1038 }
1039
1040 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1041 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1042 (req[0] & ISO15693_REQ_FLAG_OPTION))
1043 trf->issue_eof = true;
1044 }
1045
1046 return 0;
1047}
1048
1049static int trf7970a_in_send_cmd(struct nfc_digital_dev *ddev,
1050 struct sk_buff *skb, u16 timeout,
1051 nfc_digital_cmd_complete_t cb, void *arg)
1052{
1053 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1054 char *prefix;
1055 unsigned int len;
1056 int ret;
1057
1058 dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1059 trf->state, timeout, skb->len);
1060
1061 if (skb->len > TRF7970A_TX_MAX)
1062 return -EINVAL;
1063
1064 mutex_lock(&trf->lock);
1065
1066 if ((trf->state != TRF7970A_ST_IDLE) &&
1067 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1068 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1069 trf->state);
1070 ret = -EIO;
1071 goto out_err;
1072 }
1073
1074 if (trf->aborting) {
1075 dev_dbg(trf->dev, "Abort process complete\n");
1076 trf->aborting = false;
1077 ret = -ECANCELED;
1078 goto out_err;
1079 }
1080
1081 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1082 GFP_KERNEL);
1083 if (!trf->rx_skb) {
1084 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1085 ret = -ENOMEM;
1086 goto out_err;
1087 }
1088
1089 if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1090 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1091 if (ret)
1092 goto out_err;
1093
1094 trf->state = TRF7970A_ST_IDLE;
1095 }
1096
1097 ret = trf7970a_per_cmd_config(trf, skb);
1098 if (ret)
1099 goto out_err;
1100
1101 trf->ddev = ddev;
1102 trf->tx_skb = skb;
1103 trf->cb = cb;
1104 trf->cb_arg = arg;
1105 trf->timeout = timeout;
1106 trf->ignore_timeout = false;
1107
1108 len = skb->len;
1109 prefix = skb_push(skb, TRF7970A_TX_SKB_HEADROOM);
1110
1111 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1112 * on what the current framing is, the address of the TX length byte 1
1113 * register (0x1d), and the 2 byte length of the data to be transmitted.
1114 */
1115 prefix[0] = TRF7970A_CMD_BIT_CTRL |
1116 TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1117 prefix[1] = TRF7970A_CMD_BIT_CTRL |
1118 TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1119 prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1120
1121 if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1122 prefix[3] = 0x00;
1123 prefix[4] = 0x0f; /* 7 bits */
1124 } else {
1125 prefix[3] = (len & 0xf00) >> 4;
1126 prefix[3] |= ((len & 0xf0) >> 4);
1127 prefix[4] = ((len & 0x0f) << 4);
1128 }
1129
1130 len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1131
1132 usleep_range(1000, 2000);
1133
1134 ret = trf7970a_transmit(trf, skb, len);
1135 if (ret) {
1136 kfree_skb(trf->rx_skb);
1137 trf->rx_skb = NULL;
1138 }
1139
1140out_err:
1141 mutex_unlock(&trf->lock);
1142 return ret;
1143}
1144
1145static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev,
1146 int type, int param)
1147{
1148 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1149
1150 dev_dbg(trf->dev, "Unsupported interface\n");
1151
1152 return -EINVAL;
1153}
1154
1155static int trf7970a_tg_send_cmd(struct nfc_digital_dev *ddev,
1156 struct sk_buff *skb, u16 timeout,
1157 nfc_digital_cmd_complete_t cb, void *arg)
1158{
1159 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1160
1161 dev_dbg(trf->dev, "Unsupported interface\n");
1162
1163 return -EINVAL;
1164}
1165
1166static int trf7970a_tg_listen(struct nfc_digital_dev *ddev,
1167 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1168{
1169 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1170
1171 dev_dbg(trf->dev, "Unsupported interface\n");
1172
1173 return -EINVAL;
1174}
1175
1176static int trf7970a_tg_listen_mdaa(struct nfc_digital_dev *ddev,
1177 struct digital_tg_mdaa_params *mdaa_params,
1178 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1179{
1180 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1181
1182 dev_dbg(trf->dev, "Unsupported interface\n");
1183
1184 return -EINVAL;
1185}
1186
1187static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1188{
1189 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1190
1191 dev_dbg(trf->dev, "Abort process initiated\n");
1192
1193 mutex_lock(&trf->lock);
1194 trf->aborting = true;
1195 mutex_unlock(&trf->lock);
1196}
1197
1198static struct nfc_digital_ops trf7970a_nfc_ops = {
1199 .in_configure_hw = trf7970a_in_configure_hw,
1200 .in_send_cmd = trf7970a_in_send_cmd,
1201 .tg_configure_hw = trf7970a_tg_configure_hw,
1202 .tg_send_cmd = trf7970a_tg_send_cmd,
1203 .tg_listen = trf7970a_tg_listen,
1204 .tg_listen_mdaa = trf7970a_tg_listen_mdaa,
1205 .switch_rf = trf7970a_switch_rf,
1206 .abort_cmd = trf7970a_abort_cmd,
1207};
1208
1209static int trf7970a_probe(struct spi_device *spi)
1210{
1211 struct device_node *np = spi->dev.of_node;
1212 const struct spi_device_id *id = spi_get_device_id(spi);
1213 struct trf7970a *trf;
1214 int ret;
1215
1216 if (!np) {
1217 dev_err(&spi->dev, "No Device Tree entry\n");
1218 return -EINVAL;
1219 }
1220
1221 trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
1222 if (!trf)
1223 return -ENOMEM;
1224
1225 trf->state = TRF7970A_ST_OFF;
1226 trf->dev = &spi->dev;
1227 trf->spi = spi;
1228 trf->quirks = id->driver_data;
1229
1230 spi->mode = SPI_MODE_1;
1231 spi->bits_per_word = 8;
1232
1233 /* There are two enable pins - both must be present */
1234 trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
1235 if (!gpio_is_valid(trf->en_gpio)) {
1236 dev_err(trf->dev, "No EN GPIO property\n");
1237 return trf->en_gpio;
1238 }
1239
1240 ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
1241 GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN");
1242 if (ret) {
1243 dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
1244 return ret;
1245 }
1246
1247 trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
1248 if (!gpio_is_valid(trf->en2_gpio)) {
1249 dev_err(trf->dev, "No EN2 GPIO property\n");
1250 return trf->en2_gpio;
1251 }
1252
1253 ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
1254 GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN2");
1255 if (ret) {
1256 dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
1257 return ret;
1258 }
1259
1260 ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
1261 trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1262 "trf7970a", trf);
1263 if (ret) {
1264 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
1265 return ret;
1266 }
1267
1268 mutex_init(&trf->lock);
1269 INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
1270
1271 trf->regulator = devm_regulator_get(&spi->dev, "vin");
1272 if (IS_ERR(trf->regulator)) {
1273 ret = PTR_ERR(trf->regulator);
1274 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
1275 goto err_destroy_lock;
1276 }
1277
1278 ret = regulator_enable(trf->regulator);
1279 if (ret) {
1280 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
1281 goto err_destroy_lock;
1282 }
1283
1284 trf->powering_up = true;
1285
1286 trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
1287 TRF7970A_SUPPORTED_PROTOCOLS,
1288 NFC_DIGITAL_DRV_CAPS_IN_CRC, TRF7970A_TX_SKB_HEADROOM,
1289 0);
1290 if (!trf->ddev) {
1291 dev_err(trf->dev, "Can't allocate NFC digital device\n");
1292 ret = -ENOMEM;
1293 goto err_disable_regulator;
1294 }
1295
1296 nfc_digital_set_parent_dev(trf->ddev, trf->dev);
1297 nfc_digital_set_drvdata(trf->ddev, trf);
1298 spi_set_drvdata(spi, trf);
1299
1300 ret = nfc_digital_register_device(trf->ddev);
1301 if (ret) {
1302 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
1303 ret);
1304 goto err_free_ddev;
1305 }
1306
1307 return 0;
1308
1309err_free_ddev:
1310 nfc_digital_free_device(trf->ddev);
1311err_disable_regulator:
1312 regulator_disable(trf->regulator);
1313err_destroy_lock:
1314 mutex_destroy(&trf->lock);
1315 return ret;
1316}
1317
1318static int trf7970a_remove(struct spi_device *spi)
1319{
1320 struct trf7970a *trf = spi_get_drvdata(spi);
1321
1322 mutex_lock(&trf->lock);
1323
1324 trf7970a_switch_rf_off(trf);
1325 trf7970a_init(trf);
1326
1327 switch (trf->state) {
1328 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1329 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1330 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1331 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1332 trf7970a_send_err_upstream(trf, -ECANCELED);
1333 break;
1334 default:
1335 break;
1336 }
1337
1338 mutex_unlock(&trf->lock);
1339
1340 nfc_digital_unregister_device(trf->ddev);
1341 nfc_digital_free_device(trf->ddev);
1342
1343 regulator_disable(trf->regulator);
1344
1345 mutex_destroy(&trf->lock);
1346
1347 return 0;
1348}
1349
1350static const struct spi_device_id trf7970a_id_table[] = {
1351 { "trf7970a", TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA },
1352 { }
1353};
1354MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
1355
1356static struct spi_driver trf7970a_spi_driver = {
1357 .probe = trf7970a_probe,
1358 .remove = trf7970a_remove,
1359 .id_table = trf7970a_id_table,
1360 .driver = {
1361 .name = "trf7970a",
1362 .owner = THIS_MODULE,
1363 },
1364};
1365
1366module_spi_driver(trf7970a_spi_driver);
1367
1368MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
1369MODULE_LICENSE("GPL v2");
1370MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
1/*
2 * TI TRF7970a RFID/NFC Transceiver Driver
3 *
4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5 *
6 * Author: Erick Macias <emacias@ti.com>
7 * Author: Felipe Balbi <balbi@ti.com>
8 * Author: Mark A. Greer <mgreer@animalcreek.com>
9 *
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 of
12 * the License as published by the Free Software Foundation.
13 */
14
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/netdevice.h>
18#include <linux/interrupt.h>
19#include <linux/pm_runtime.h>
20#include <linux/nfc.h>
21#include <linux/skbuff.h>
22#include <linux/delay.h>
23#include <linux/gpio/consumer.h>
24#include <linux/of.h>
25#include <linux/spi/spi.h>
26#include <linux/regulator/consumer.h>
27
28#include <net/nfc/nfc.h>
29#include <net/nfc/digital.h>
30
31/* There are 3 ways the host can communicate with the trf7970a:
32 * parallel mode, SPI with Slave Select (SS) mode, and SPI without
33 * SS mode. The driver only supports the two SPI modes.
34 *
35 * The trf7970a is very timing sensitive and the VIN, EN2, and EN
36 * pins must asserted in that order and with specific delays in between.
37 * The delays used in the driver were provided by TI and have been
38 * confirmed to work with this driver. There is a bug with the current
39 * version of the trf7970a that requires that EN2 remain low no matter
40 * what. If it goes high, it will generate an RF field even when in
41 * passive target mode. TI has indicated that the chip will work okay
42 * when EN2 is left low. The 'en2-rf-quirk' device tree property
43 * indicates that trf7970a currently being used has the erratum and
44 * that EN2 must be kept low.
45 *
46 * Timeouts are implemented using the delayed workqueue kernel facility.
47 * Timeouts are required so things don't hang when there is no response
48 * from the trf7970a (or tag). Using this mechanism creates a race with
49 * interrupts, however. That is, an interrupt and a timeout could occur
50 * closely enough together that one is blocked by the mutex while the other
51 * executes. When the timeout handler executes first and blocks the
52 * interrupt handler, it will eventually set the state to IDLE so the
53 * interrupt handler will check the state and exit with no harm done.
54 * When the interrupt handler executes first and blocks the timeout handler,
55 * the cancel_delayed_work() call will know that it didn't cancel the
56 * work item (i.e., timeout) and will return zero. That return code is
57 * used by the timer handler to indicate that it should ignore the timeout
58 * once its unblocked.
59 *
60 * Aborting an active command isn't as simple as it seems because the only
61 * way to abort a command that's already been sent to the tag is so turn
62 * off power to the tag. If we do that, though, we'd have to go through
63 * the entire anticollision procedure again but the digital layer doesn't
64 * support that. So, if an abort is received before trf7970a_send_cmd()
65 * has sent the command to the tag, it simply returns -ECANCELED. If the
66 * command has already been sent to the tag, then the driver continues
67 * normally and recieves the response data (or error) but just before
68 * sending the data upstream, it frees the rx_skb and sends -ECANCELED
69 * upstream instead. If the command failed, that error will be sent
70 * upstream.
71 *
72 * When recieving data from a tag and the interrupt status register has
73 * only the SRX bit set, it means that all of the data has been received
74 * (once what's in the fifo has been read). However, depending on timing
75 * an interrupt status with only the SRX bit set may not be recived. In
76 * those cases, the timeout mechanism is used to wait 20 ms in case more
77 * data arrives. After 20 ms, it is assumed that all of the data has been
78 * received and the accumulated rx data is sent upstream. The
79 * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
80 * (i.e., it indicates that some data has been received but we're not sure
81 * if there is more coming so a timeout in this state means all data has
82 * been received and there isn't an error). The delay is 20 ms since delays
83 * of ~16 ms have been observed during testing.
84 *
85 * When transmitting a frame larger than the FIFO size (127 bytes), the
86 * driver will wait 20 ms for the FIFO to drain past the low-watermark
87 * and generate an interrupt. The low-watermark set to 32 bytes so the
88 * interrupt should fire after 127 - 32 = 95 bytes have been sent. At
89 * the lowest possible bit rate (6.62 kbps for 15693), it will take up
90 * to ~14.35 ms so 20 ms is used for the timeout.
91 *
92 * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
93 * Having only 4 bits in the FIFO won't normally generate an interrupt so
94 * driver enables the '4_bit_RX' bit of the Special Functions register 1
95 * to cause an interrupt in that case. Leaving that bit for a read command
96 * messes up the data returned so it is only enabled when the framing is
97 * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
98 * Unfortunately, that means that the driver has to peek into tx frames
99 * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by
100 * the trf7970a_per_cmd_config() routine.
101 *
102 * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
103 * frequencies and whether to use low or high data rates in the flags byte
104 * of the frame. This means that the driver has to peek at all 15693 frames
105 * to determine what speed to set the communication to. In addition, write
106 * and lock commands use the OPTION flag to indicate that an EOF must be
107 * sent to the tag before it will send its response. So the driver has to
108 * examine all frames for that reason too.
109 *
110 * It is unclear how long to wait before sending the EOF. According to the
111 * Note under Table 1-1 in section 1.6 of
112 * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
113 * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
114 * enough so 20 ms is used. So the timer is set to 40 ms - 20 ms to drain
115 * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
116 * ensure the wait is long enough before sending the EOF. This seems to work
117 * reliably.
118 */
119
120#define TRF7970A_SUPPORTED_PROTOCOLS \
121 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
122 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
123 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
124
125#define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */
126#define TRF7970A_13MHZ_CLOCK_FREQUENCY 13560000
127#define TRF7970A_27MHZ_CLOCK_FREQUENCY 27120000
128
129#define TRF7970A_RX_SKB_ALLOC_SIZE 256
130
131#define TRF7970A_FIFO_SIZE 127
132
133/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
134#define TRF7970A_TX_MAX (4096 - 1)
135
136#define TRF7970A_WAIT_FOR_TX_IRQ 20
137#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20
138#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 20
139#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40
140
141/* Guard times for various RF technologies (in us) */
142#define TRF7970A_GUARD_TIME_NFCA 5000
143#define TRF7970A_GUARD_TIME_NFCB 5000
144#define TRF7970A_GUARD_TIME_NFCF 20000
145#define TRF7970A_GUARD_TIME_15693 1000
146
147/* Quirks */
148/* Erratum: When reading IRQ Status register on trf7970a, we must issue a
149 * read continuous command for IRQ Status and Collision Position registers.
150 */
151#define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0)
152#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1)
153
154/* Direct commands */
155#define TRF7970A_CMD_IDLE 0x00
156#define TRF7970A_CMD_SOFT_INIT 0x03
157#define TRF7970A_CMD_RF_COLLISION 0x04
158#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05
159#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06
160#define TRF7970A_CMD_FIFO_RESET 0x0f
161#define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10
162#define TRF7970A_CMD_TRANSMIT 0x11
163#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12
164#define TRF7970A_CMD_DELAY_TRANSMIT 0x13
165#define TRF7970A_CMD_EOF 0x14
166#define TRF7970A_CMD_CLOSE_SLOT 0x15
167#define TRF7970A_CMD_BLOCK_RX 0x16
168#define TRF7970A_CMD_ENABLE_RX 0x17
169#define TRF7970A_CMD_TEST_INT_RF 0x18
170#define TRF7970A_CMD_TEST_EXT_RF 0x19
171#define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a
172
173/* Bits determining whether its a direct command or register R/W,
174 * whether to use a continuous SPI transaction or not, and the actual
175 * direct cmd opcode or regster address.
176 */
177#define TRF7970A_CMD_BIT_CTRL BIT(7)
178#define TRF7970A_CMD_BIT_RW BIT(6)
179#define TRF7970A_CMD_BIT_CONTINUOUS BIT(5)
180#define TRF7970A_CMD_BIT_OPCODE(opcode) ((opcode) & 0x1f)
181
182/* Registers addresses */
183#define TRF7970A_CHIP_STATUS_CTRL 0x00
184#define TRF7970A_ISO_CTRL 0x01
185#define TRF7970A_ISO14443B_TX_OPTIONS 0x02
186#define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
187#define TRF7970A_TX_TIMER_SETTING_H_BYTE 0x04
188#define TRF7970A_TX_TIMER_SETTING_L_BYTE 0x05
189#define TRF7970A_TX_PULSE_LENGTH_CTRL 0x06
190#define TRF7970A_RX_NO_RESPONSE_WAIT 0x07
191#define TRF7970A_RX_WAIT_TIME 0x08
192#define TRF7970A_MODULATOR_SYS_CLK_CTRL 0x09
193#define TRF7970A_RX_SPECIAL_SETTINGS 0x0a
194#define TRF7970A_REG_IO_CTRL 0x0b
195#define TRF7970A_IRQ_STATUS 0x0c
196#define TRF7970A_COLLISION_IRQ_MASK 0x0d
197#define TRF7970A_COLLISION_POSITION 0x0e
198#define TRF7970A_RSSI_OSC_STATUS 0x0f
199#define TRF7970A_SPECIAL_FCN_REG1 0x10
200#define TRF7970A_SPECIAL_FCN_REG2 0x11
201#define TRF7970A_RAM1 0x12
202#define TRF7970A_RAM2 0x13
203#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS 0x14
204#define TRF7970A_NFC_LOW_FIELD_LEVEL 0x16
205#define TRF7970A_NFCID1 0x17
206#define TRF7970A_NFC_TARGET_LEVEL 0x18
207#define TRF79070A_NFC_TARGET_PROTOCOL 0x19
208#define TRF7970A_TEST_REGISTER1 0x1a
209#define TRF7970A_TEST_REGISTER2 0x1b
210#define TRF7970A_FIFO_STATUS 0x1c
211#define TRF7970A_TX_LENGTH_BYTE1 0x1d
212#define TRF7970A_TX_LENGTH_BYTE2 0x1e
213#define TRF7970A_FIFO_IO_REGISTER 0x1f
214
215/* Chip Status Control Register Bits */
216#define TRF7970A_CHIP_STATUS_VRS5_3 BIT(0)
217#define TRF7970A_CHIP_STATUS_REC_ON BIT(1)
218#define TRF7970A_CHIP_STATUS_AGC_ON BIT(2)
219#define TRF7970A_CHIP_STATUS_PM_ON BIT(3)
220#define TRF7970A_CHIP_STATUS_RF_PWR BIT(4)
221#define TRF7970A_CHIP_STATUS_RF_ON BIT(5)
222#define TRF7970A_CHIP_STATUS_DIRECT BIT(6)
223#define TRF7970A_CHIP_STATUS_STBY BIT(7)
224
225/* ISO Control Register Bits */
226#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662 0x00
227#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662 0x01
228#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648 0x02
229#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
230#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a 0x04
231#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667 0x05
232#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669 0x06
233#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
234#define TRF7970A_ISO_CTRL_14443A_106 0x08
235#define TRF7970A_ISO_CTRL_14443A_212 0x09
236#define TRF7970A_ISO_CTRL_14443A_424 0x0a
237#define TRF7970A_ISO_CTRL_14443A_848 0x0b
238#define TRF7970A_ISO_CTRL_14443B_106 0x0c
239#define TRF7970A_ISO_CTRL_14443B_212 0x0d
240#define TRF7970A_ISO_CTRL_14443B_424 0x0e
241#define TRF7970A_ISO_CTRL_14443B_848 0x0f
242#define TRF7970A_ISO_CTRL_FELICA_212 0x1a
243#define TRF7970A_ISO_CTRL_FELICA_424 0x1b
244#define TRF7970A_ISO_CTRL_NFC_NFCA_106 0x01
245#define TRF7970A_ISO_CTRL_NFC_NFCF_212 0x02
246#define TRF7970A_ISO_CTRL_NFC_NFCF_424 0x03
247#define TRF7970A_ISO_CTRL_NFC_CE_14443A 0x00
248#define TRF7970A_ISO_CTRL_NFC_CE_14443B 0x01
249#define TRF7970A_ISO_CTRL_NFC_CE BIT(2)
250#define TRF7970A_ISO_CTRL_NFC_ACTIVE BIT(3)
251#define TRF7970A_ISO_CTRL_NFC_INITIATOR BIT(4)
252#define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE BIT(5)
253#define TRF7970A_ISO_CTRL_RFID BIT(5)
254#define TRF7970A_ISO_CTRL_DIR_MODE BIT(6)
255#define TRF7970A_ISO_CTRL_RX_CRC_N BIT(7) /* true == No CRC */
256
257#define TRF7970A_ISO_CTRL_RFID_SPEED_MASK 0x1f
258
259/* Modulator and SYS_CLK Control Register Bits */
260#define TRF7970A_MODULATOR_DEPTH(n) ((n) & 0x7)
261#define TRF7970A_MODULATOR_DEPTH_ASK10 (TRF7970A_MODULATOR_DEPTH(0))
262#define TRF7970A_MODULATOR_DEPTH_OOK (TRF7970A_MODULATOR_DEPTH(1))
263#define TRF7970A_MODULATOR_DEPTH_ASK7 (TRF7970A_MODULATOR_DEPTH(2))
264#define TRF7970A_MODULATOR_DEPTH_ASK8_5 (TRF7970A_MODULATOR_DEPTH(3))
265#define TRF7970A_MODULATOR_DEPTH_ASK13 (TRF7970A_MODULATOR_DEPTH(4))
266#define TRF7970A_MODULATOR_DEPTH_ASK16 (TRF7970A_MODULATOR_DEPTH(5))
267#define TRF7970A_MODULATOR_DEPTH_ASK22 (TRF7970A_MODULATOR_DEPTH(6))
268#define TRF7970A_MODULATOR_DEPTH_ASK30 (TRF7970A_MODULATOR_DEPTH(7))
269#define TRF7970A_MODULATOR_EN_ANA BIT(3)
270#define TRF7970A_MODULATOR_CLK(n) (((n) & 0x3) << 4)
271#define TRF7970A_MODULATOR_CLK_DISABLED (TRF7970A_MODULATOR_CLK(0))
272#define TRF7970A_MODULATOR_CLK_3_6 (TRF7970A_MODULATOR_CLK(1))
273#define TRF7970A_MODULATOR_CLK_6_13 (TRF7970A_MODULATOR_CLK(2))
274#define TRF7970A_MODULATOR_CLK_13_27 (TRF7970A_MODULATOR_CLK(3))
275#define TRF7970A_MODULATOR_EN_OOK BIT(6)
276#define TRF7970A_MODULATOR_27MHZ BIT(7)
277
278#define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
279#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR BIT(1)
280#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << 2)
281#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << 2)
282#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << 2)
283#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << 2)
284#define TRF7970A_RX_SPECIAL_SETTINGS_HBT BIT(4)
285#define TRF7970A_RX_SPECIAL_SETTINGS_M848 BIT(5)
286#define TRF7970A_RX_SPECIAL_SETTINGS_C424 BIT(6)
287#define TRF7970A_RX_SPECIAL_SETTINGS_C212 BIT(7)
288
289#define TRF7970A_REG_IO_CTRL_VRS(v) ((v) & 0x07)
290#define TRF7970A_REG_IO_CTRL_IO_LOW BIT(5)
291#define TRF7970A_REG_IO_CTRL_EN_EXT_PA BIT(6)
292#define TRF7970A_REG_IO_CTRL_AUTO_REG BIT(7)
293
294/* IRQ Status Register Bits */
295#define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
296#define TRF7970A_IRQ_STATUS_NFC_COL_ERROR BIT(0)
297#define TRF7970A_IRQ_STATUS_COL BIT(1)
298#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
299#define TRF7970A_IRQ_STATUS_NFC_RF BIT(2)
300#define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
301#define TRF7970A_IRQ_STATUS_NFC_SDD BIT(3)
302#define TRF7970A_IRQ_STATUS_CRC_ERROR BIT(4)
303#define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR BIT(4)
304#define TRF7970A_IRQ_STATUS_FIFO BIT(5)
305#define TRF7970A_IRQ_STATUS_SRX BIT(6)
306#define TRF7970A_IRQ_STATUS_TX BIT(7)
307
308#define TRF7970A_IRQ_STATUS_ERROR \
309 (TRF7970A_IRQ_STATUS_COL | \
310 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR | \
311 TRF7970A_IRQ_STATUS_PARITY_ERROR | \
312 TRF7970A_IRQ_STATUS_CRC_ERROR)
313
314#define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK (BIT(2) | BIT(1) | BIT(0))
315#define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK (BIT(5) | BIT(4) | BIT(3))
316#define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK BIT(6)
317
318#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6 BIT(0)
319#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL BIT(1)
320#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX BIT(2)
321#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE BIT(3)
322#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US BIT(4)
323#define TRF7970A_SPECIAL_FCN_REG1_PAR43 BIT(5)
324
325#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124 (0x0 << 2)
326#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120 (0x1 << 2)
327#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112 (0x2 << 2)
328#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 (0x3 << 2)
329#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4 0x0
330#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8 0x1
331#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16 0x2
332#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32 0x3
333
334#define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v) ((v) & 0x07)
335#define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS BIT(7)
336
337#define TRF7970A_NFC_TARGET_LEVEL_RFDET(v) ((v) & 0x07)
338#define TRF7970A_NFC_TARGET_LEVEL_HI_RF BIT(3)
339#define TRF7970A_NFC_TARGET_LEVEL_SDD_EN BIT(5)
340#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES (0x0 << 6)
341#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES (0x1 << 6)
342#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES (0x2 << 6)
343
344#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106 BIT(0)
345#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212 BIT(1)
346#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424 (BIT(0) | BIT(1))
347#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B BIT(2)
348#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 BIT(3)
349#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA BIT(4)
350#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L BIT(6)
351#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H BIT(7)
352
353#define TRF79070A_NFC_TARGET_PROTOCOL_106A \
354 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
355 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
356 TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 | \
357 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
358
359#define TRF79070A_NFC_TARGET_PROTOCOL_106B \
360 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
361 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
362 TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B | \
363 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
364
365#define TRF79070A_NFC_TARGET_PROTOCOL_212F \
366 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
367 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
368 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
369 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
370
371#define TRF79070A_NFC_TARGET_PROTOCOL_424F \
372 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
373 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
374 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
375 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
376
377#define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7)
378
379/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
380#define NFC_T2T_CMD_READ 0x30
381
382/* ISO 15693 commands codes */
383#define ISO15693_CMD_INVENTORY 0x01
384#define ISO15693_CMD_READ_SINGLE_BLOCK 0x20
385#define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21
386#define ISO15693_CMD_LOCK_BLOCK 0x22
387#define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23
388#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24
389#define ISO15693_CMD_SELECT 0x25
390#define ISO15693_CMD_RESET_TO_READY 0x26
391#define ISO15693_CMD_WRITE_AFI 0x27
392#define ISO15693_CMD_LOCK_AFI 0x28
393#define ISO15693_CMD_WRITE_DSFID 0x29
394#define ISO15693_CMD_LOCK_DSFID 0x2a
395#define ISO15693_CMD_GET_SYSTEM_INFO 0x2b
396#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
397
398/* ISO 15693 request and response flags */
399#define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0)
400#define ISO15693_REQ_FLAG_DATA_RATE BIT(1)
401#define ISO15693_REQ_FLAG_INVENTORY BIT(2)
402#define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3)
403#define ISO15693_REQ_FLAG_SELECT BIT(4)
404#define ISO15693_REQ_FLAG_AFI BIT(4)
405#define ISO15693_REQ_FLAG_ADDRESS BIT(5)
406#define ISO15693_REQ_FLAG_NB_SLOTS BIT(5)
407#define ISO15693_REQ_FLAG_OPTION BIT(6)
408
409#define ISO15693_REQ_FLAG_SPEED_MASK \
410 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
411
412enum trf7970a_state {
413 TRF7970A_ST_PWR_OFF,
414 TRF7970A_ST_RF_OFF,
415 TRF7970A_ST_IDLE,
416 TRF7970A_ST_IDLE_RX_BLOCKED,
417 TRF7970A_ST_WAIT_FOR_TX_FIFO,
418 TRF7970A_ST_WAIT_FOR_RX_DATA,
419 TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
420 TRF7970A_ST_WAIT_TO_ISSUE_EOF,
421 TRF7970A_ST_LISTENING,
422 TRF7970A_ST_LISTENING_MD,
423 TRF7970A_ST_MAX
424};
425
426struct trf7970a {
427 enum trf7970a_state state;
428 struct device *dev;
429 struct spi_device *spi;
430 struct regulator *regulator;
431 struct nfc_digital_dev *ddev;
432 u32 quirks;
433 bool is_initiator;
434 bool aborting;
435 struct sk_buff *tx_skb;
436 struct sk_buff *rx_skb;
437 nfc_digital_cmd_complete_t cb;
438 void *cb_arg;
439 u8 chip_status_ctrl;
440 u8 iso_ctrl;
441 u8 iso_ctrl_tech;
442 u8 modulator_sys_clk_ctrl;
443 u8 special_fcn_reg1;
444 u8 io_ctrl;
445 unsigned int guard_time;
446 int technology;
447 int framing;
448 u8 md_rf_tech;
449 u8 tx_cmd;
450 bool issue_eof;
451 struct gpio_desc *en_gpiod;
452 struct gpio_desc *en2_gpiod;
453 struct mutex lock;
454 unsigned int timeout;
455 bool ignore_timeout;
456 struct delayed_work timeout_work;
457};
458
459static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
460{
461 u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
462 int ret;
463
464 dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
465
466 ret = spi_write(trf->spi, &cmd, 1);
467 if (ret)
468 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
469 ret);
470 return ret;
471}
472
473static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
474{
475 u8 addr = TRF7970A_CMD_BIT_RW | reg;
476 int ret;
477
478 ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
479 if (ret)
480 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
481 ret);
482
483 dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
484
485 return ret;
486}
487
488static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
489 size_t len)
490{
491 u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
492 struct spi_transfer t[2];
493 struct spi_message m;
494 int ret;
495
496 dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
497
498 spi_message_init(&m);
499
500 memset(&t, 0, sizeof(t));
501
502 t[0].tx_buf = &addr;
503 t[0].len = sizeof(addr);
504 spi_message_add_tail(&t[0], &m);
505
506 t[1].rx_buf = buf;
507 t[1].len = len;
508 spi_message_add_tail(&t[1], &m);
509
510 ret = spi_sync(trf->spi, &m);
511 if (ret)
512 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
513 ret);
514 return ret;
515}
516
517static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
518{
519 u8 buf[2] = { reg, val };
520 int ret;
521
522 dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
523
524 ret = spi_write(trf->spi, buf, 2);
525 if (ret)
526 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
527 buf[0], buf[1], ret);
528
529 return ret;
530}
531
532static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
533{
534 int ret;
535 u8 buf[2];
536 u8 addr;
537
538 addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
539
540 if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
541 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
542 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
543 } else {
544 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
545 }
546
547 if (ret)
548 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
549 __func__, ret);
550 else
551 *status = buf[0];
552
553 return ret;
554}
555
556static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
557{
558 int ret;
559 u8 buf[2];
560 u8 addr;
561
562 addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
563 TRF7970A_CMD_BIT_CONTINUOUS;
564
565 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
566 if (ret)
567 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
568 __func__, ret);
569 else
570 *target_proto = buf[0];
571
572 return ret;
573}
574
575static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
576{
577 int ret;
578 u8 target_proto, tech;
579
580 ret = trf7970a_read_target_proto(trf, &target_proto);
581 if (ret)
582 return ret;
583
584 switch (target_proto) {
585 case TRF79070A_NFC_TARGET_PROTOCOL_106A:
586 tech = NFC_DIGITAL_RF_TECH_106A;
587 break;
588 case TRF79070A_NFC_TARGET_PROTOCOL_106B:
589 tech = NFC_DIGITAL_RF_TECH_106B;
590 break;
591 case TRF79070A_NFC_TARGET_PROTOCOL_212F:
592 tech = NFC_DIGITAL_RF_TECH_212F;
593 break;
594 case TRF79070A_NFC_TARGET_PROTOCOL_424F:
595 tech = NFC_DIGITAL_RF_TECH_424F;
596 break;
597 default:
598 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
599 __func__, target_proto);
600 return -EIO;
601 }
602
603 *rf_tech = tech;
604
605 return ret;
606}
607
608static void trf7970a_send_upstream(struct trf7970a *trf)
609{
610 dev_kfree_skb_any(trf->tx_skb);
611 trf->tx_skb = NULL;
612
613 if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
614 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
615 16, 1, trf->rx_skb->data, trf->rx_skb->len,
616 false);
617
618 trf->state = TRF7970A_ST_IDLE;
619
620 if (trf->aborting) {
621 dev_dbg(trf->dev, "Abort process complete\n");
622
623 if (!IS_ERR(trf->rx_skb)) {
624 kfree_skb(trf->rx_skb);
625 trf->rx_skb = ERR_PTR(-ECANCELED);
626 }
627
628 trf->aborting = false;
629 }
630
631 trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
632
633 trf->rx_skb = NULL;
634}
635
636static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
637{
638 dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
639
640 cancel_delayed_work(&trf->timeout_work);
641
642 kfree_skb(trf->rx_skb);
643 trf->rx_skb = ERR_PTR(errno);
644
645 trf7970a_send_upstream(trf);
646}
647
648static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
649 unsigned int len, u8 *prefix,
650 unsigned int prefix_len)
651{
652 struct spi_transfer t[2];
653 struct spi_message m;
654 unsigned int timeout;
655 int ret;
656
657 print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
658 16, 1, skb->data, len, false);
659
660 spi_message_init(&m);
661
662 memset(&t, 0, sizeof(t));
663
664 t[0].tx_buf = prefix;
665 t[0].len = prefix_len;
666 spi_message_add_tail(&t[0], &m);
667
668 t[1].tx_buf = skb->data;
669 t[1].len = len;
670 spi_message_add_tail(&t[1], &m);
671
672 ret = spi_sync(trf->spi, &m);
673 if (ret) {
674 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
675 ret);
676 return ret;
677 }
678
679 skb_pull(skb, len);
680
681 if (skb->len > 0) {
682 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
683 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
684 } else {
685 if (trf->issue_eof) {
686 trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
687 timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
688 } else {
689 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
690
691 if (!trf->timeout)
692 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
693 else
694 timeout = trf->timeout;
695 }
696 }
697
698 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
699 trf->state);
700
701 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
702
703 return 0;
704}
705
706static void trf7970a_fill_fifo(struct trf7970a *trf)
707{
708 struct sk_buff *skb = trf->tx_skb;
709 unsigned int len;
710 int ret;
711 u8 fifo_bytes;
712 u8 prefix;
713
714 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
715 if (ret) {
716 trf7970a_send_err_upstream(trf, ret);
717 return;
718 }
719
720 dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
721
722 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
723
724 /* Calculate how much more data can be written to the fifo */
725 len = TRF7970A_FIFO_SIZE - fifo_bytes;
726 if (!len) {
727 schedule_delayed_work(&trf->timeout_work,
728 msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
729 return;
730 }
731
732 len = min(skb->len, len);
733
734 prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
735
736 ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
737 if (ret)
738 trf7970a_send_err_upstream(trf, ret);
739}
740
741static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
742{
743 struct sk_buff *skb = trf->rx_skb;
744 int ret;
745 u8 fifo_bytes;
746
747 if (status & TRF7970A_IRQ_STATUS_ERROR) {
748 trf7970a_send_err_upstream(trf, -EIO);
749 return;
750 }
751
752 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
753 if (ret) {
754 trf7970a_send_err_upstream(trf, ret);
755 return;
756 }
757
758 dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
759
760 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
761
762 if (!fifo_bytes)
763 goto no_rx_data;
764
765 if (fifo_bytes > skb_tailroom(skb)) {
766 skb = skb_copy_expand(skb, skb_headroom(skb),
767 max_t(int, fifo_bytes,
768 TRF7970A_RX_SKB_ALLOC_SIZE),
769 GFP_KERNEL);
770 if (!skb) {
771 trf7970a_send_err_upstream(trf, -ENOMEM);
772 return;
773 }
774
775 kfree_skb(trf->rx_skb);
776 trf->rx_skb = skb;
777 }
778
779 ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
780 skb_put(skb, fifo_bytes), fifo_bytes);
781 if (ret) {
782 trf7970a_send_err_upstream(trf, ret);
783 return;
784 }
785
786 /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
787 if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
788 (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
789 skb->data[0] >>= 4;
790 status = TRF7970A_IRQ_STATUS_SRX;
791 } else {
792 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
793
794 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
795 if (ret) {
796 trf7970a_send_err_upstream(trf, ret);
797 return;
798 }
799
800 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
801
802 /* If there are bytes in the FIFO, set status to '0' so
803 * the if stmt below doesn't fire and the driver will wait
804 * for the trf7970a to generate another RX interrupt.
805 */
806 if (fifo_bytes)
807 status = 0;
808 }
809
810no_rx_data:
811 if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
812 trf7970a_send_upstream(trf);
813 return;
814 }
815
816 dev_dbg(trf->dev, "Setting timeout for %d ms\n",
817 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
818
819 schedule_delayed_work(&trf->timeout_work,
820 msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
821}
822
823static irqreturn_t trf7970a_irq(int irq, void *dev_id)
824{
825 struct trf7970a *trf = dev_id;
826 int ret;
827 u8 status, fifo_bytes, iso_ctrl;
828
829 mutex_lock(&trf->lock);
830
831 if (trf->state == TRF7970A_ST_RF_OFF) {
832 mutex_unlock(&trf->lock);
833 return IRQ_NONE;
834 }
835
836 ret = trf7970a_read_irqstatus(trf, &status);
837 if (ret) {
838 mutex_unlock(&trf->lock);
839 return IRQ_NONE;
840 }
841
842 dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
843 status);
844
845 if (!status) {
846 mutex_unlock(&trf->lock);
847 return IRQ_NONE;
848 }
849
850 switch (trf->state) {
851 case TRF7970A_ST_IDLE:
852 case TRF7970A_ST_IDLE_RX_BLOCKED:
853 /* If initiator and getting interrupts caused by RF noise,
854 * turn off the receiver to avoid unnecessary interrupts.
855 * It will be turned back on in trf7970a_send_cmd() when
856 * the next command is issued.
857 */
858 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
859 trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
860 trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
861 }
862
863 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
864 break;
865 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
866 if (status & TRF7970A_IRQ_STATUS_TX) {
867 trf->ignore_timeout =
868 !cancel_delayed_work(&trf->timeout_work);
869 trf7970a_fill_fifo(trf);
870 } else {
871 trf7970a_send_err_upstream(trf, -EIO);
872 }
873 break;
874 case TRF7970A_ST_WAIT_FOR_RX_DATA:
875 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
876 if (status & TRF7970A_IRQ_STATUS_SRX) {
877 trf->ignore_timeout =
878 !cancel_delayed_work(&trf->timeout_work);
879 trf7970a_drain_fifo(trf, status);
880 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
881 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
882 &fifo_bytes);
883
884 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
885
886 if (ret)
887 trf7970a_send_err_upstream(trf, ret);
888 else if (!fifo_bytes)
889 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
890 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
891 (!trf->is_initiator &&
892 (status == (TRF7970A_IRQ_STATUS_TX |
893 TRF7970A_IRQ_STATUS_NFC_RF)))) {
894 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
895
896 if (!trf->timeout) {
897 trf->ignore_timeout =
898 !cancel_delayed_work(&trf->timeout_work);
899 trf->rx_skb = ERR_PTR(0);
900 trf7970a_send_upstream(trf);
901 break;
902 }
903
904 if (trf->is_initiator)
905 break;
906
907 iso_ctrl = trf->iso_ctrl;
908
909 switch (trf->framing) {
910 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
911 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
912 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
913 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
914 break;
915 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
916 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
917 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
918 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
919 break;
920 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
921 ret = trf7970a_write(trf,
922 TRF7970A_SPECIAL_FCN_REG1,
923 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
924 if (ret)
925 goto err_unlock_exit;
926
927 trf->special_fcn_reg1 =
928 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
929 break;
930 default:
931 break;
932 }
933
934 if (iso_ctrl != trf->iso_ctrl) {
935 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
936 iso_ctrl);
937 if (ret)
938 goto err_unlock_exit;
939
940 trf->iso_ctrl = iso_ctrl;
941 }
942 } else {
943 trf7970a_send_err_upstream(trf, -EIO);
944 }
945 break;
946 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
947 if (status != TRF7970A_IRQ_STATUS_TX)
948 trf7970a_send_err_upstream(trf, -EIO);
949 break;
950 case TRF7970A_ST_LISTENING:
951 if (status & TRF7970A_IRQ_STATUS_SRX) {
952 trf->ignore_timeout =
953 !cancel_delayed_work(&trf->timeout_work);
954 trf7970a_drain_fifo(trf, status);
955 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
956 trf7970a_send_err_upstream(trf, -EIO);
957 }
958 break;
959 case TRF7970A_ST_LISTENING_MD:
960 if (status & TRF7970A_IRQ_STATUS_SRX) {
961 trf->ignore_timeout =
962 !cancel_delayed_work(&trf->timeout_work);
963
964 ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
965 if (ret) {
966 trf7970a_send_err_upstream(trf, ret);
967 } else {
968 trf->state = TRF7970A_ST_LISTENING;
969 trf7970a_drain_fifo(trf, status);
970 }
971 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
972 trf7970a_send_err_upstream(trf, -EIO);
973 }
974 break;
975 default:
976 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
977 __func__, trf->state);
978 }
979
980err_unlock_exit:
981 mutex_unlock(&trf->lock);
982 return IRQ_HANDLED;
983}
984
985static void trf7970a_issue_eof(struct trf7970a *trf)
986{
987 int ret;
988
989 dev_dbg(trf->dev, "Issuing EOF\n");
990
991 ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
992 if (ret)
993 trf7970a_send_err_upstream(trf, ret);
994
995 ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
996 if (ret)
997 trf7970a_send_err_upstream(trf, ret);
998
999 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1000
1001 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1002 trf->timeout, trf->state);
1003
1004 schedule_delayed_work(&trf->timeout_work,
1005 msecs_to_jiffies(trf->timeout));
1006}
1007
1008static void trf7970a_timeout_work_handler(struct work_struct *work)
1009{
1010 struct trf7970a *trf = container_of(work, struct trf7970a,
1011 timeout_work.work);
1012
1013 dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1014 trf->state, trf->ignore_timeout);
1015
1016 mutex_lock(&trf->lock);
1017
1018 if (trf->ignore_timeout)
1019 trf->ignore_timeout = false;
1020 else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1021 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1022 else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1023 trf7970a_issue_eof(trf);
1024 else
1025 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1026
1027 mutex_unlock(&trf->lock);
1028}
1029
1030static int trf7970a_init(struct trf7970a *trf)
1031{
1032 int ret;
1033
1034 dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1035
1036 ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1037 if (ret)
1038 goto err_out;
1039
1040 ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1041 if (ret)
1042 goto err_out;
1043
1044 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1045 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1046 if (ret)
1047 goto err_out;
1048
1049 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1050 if (ret)
1051 goto err_out;
1052
1053 usleep_range(1000, 2000);
1054
1055 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1056
1057 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1058 trf->modulator_sys_clk_ctrl);
1059 if (ret)
1060 goto err_out;
1061
1062 ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1063 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1064 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1065 if (ret)
1066 goto err_out;
1067
1068 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1069 if (ret)
1070 goto err_out;
1071
1072 trf->special_fcn_reg1 = 0;
1073
1074 trf->iso_ctrl = 0xff;
1075 return 0;
1076
1077err_out:
1078 dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1079 return ret;
1080}
1081
1082static void trf7970a_switch_rf_off(struct trf7970a *trf)
1083{
1084 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1085 (trf->state == TRF7970A_ST_RF_OFF))
1086 return;
1087
1088 dev_dbg(trf->dev, "Switching rf off\n");
1089
1090 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1091
1092 trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1093
1094 trf->aborting = false;
1095 trf->state = TRF7970A_ST_RF_OFF;
1096
1097 pm_runtime_mark_last_busy(trf->dev);
1098 pm_runtime_put_autosuspend(trf->dev);
1099}
1100
1101static int trf7970a_switch_rf_on(struct trf7970a *trf)
1102{
1103 int ret;
1104
1105 dev_dbg(trf->dev, "Switching rf on\n");
1106
1107 pm_runtime_get_sync(trf->dev);
1108
1109 if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1110 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1111 trf->state);
1112 return -EINVAL;
1113 }
1114
1115 ret = trf7970a_init(trf);
1116 if (ret) {
1117 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1118 return ret;
1119 }
1120
1121 trf->state = TRF7970A_ST_IDLE;
1122
1123 return 0;
1124}
1125
1126static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1127{
1128 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1129 int ret = 0;
1130
1131 dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1132
1133 mutex_lock(&trf->lock);
1134
1135 if (on) {
1136 switch (trf->state) {
1137 case TRF7970A_ST_PWR_OFF:
1138 case TRF7970A_ST_RF_OFF:
1139 ret = trf7970a_switch_rf_on(trf);
1140 break;
1141 case TRF7970A_ST_IDLE:
1142 case TRF7970A_ST_IDLE_RX_BLOCKED:
1143 break;
1144 default:
1145 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1146 __func__, trf->state, on);
1147 trf7970a_switch_rf_off(trf);
1148 ret = -EINVAL;
1149 }
1150 } else {
1151 switch (trf->state) {
1152 case TRF7970A_ST_PWR_OFF:
1153 case TRF7970A_ST_RF_OFF:
1154 break;
1155 default:
1156 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1157 __func__, trf->state, on);
1158 ret = -EINVAL;
1159 /* FALLTHROUGH */
1160 case TRF7970A_ST_IDLE:
1161 case TRF7970A_ST_IDLE_RX_BLOCKED:
1162 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1163 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1164 trf7970a_switch_rf_off(trf);
1165 }
1166 }
1167
1168 mutex_unlock(&trf->lock);
1169 return ret;
1170}
1171
1172static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1173{
1174 int ret = 0;
1175
1176 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1177
1178 switch (tech) {
1179 case NFC_DIGITAL_RF_TECH_106A:
1180 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1181 trf->modulator_sys_clk_ctrl =
1182 (trf->modulator_sys_clk_ctrl & 0xf8) |
1183 TRF7970A_MODULATOR_DEPTH_OOK;
1184 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1185 break;
1186 case NFC_DIGITAL_RF_TECH_106B:
1187 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1188 trf->modulator_sys_clk_ctrl =
1189 (trf->modulator_sys_clk_ctrl & 0xf8) |
1190 TRF7970A_MODULATOR_DEPTH_ASK10;
1191 trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1192 break;
1193 case NFC_DIGITAL_RF_TECH_212F:
1194 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1195 trf->modulator_sys_clk_ctrl =
1196 (trf->modulator_sys_clk_ctrl & 0xf8) |
1197 TRF7970A_MODULATOR_DEPTH_ASK10;
1198 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1199 break;
1200 case NFC_DIGITAL_RF_TECH_424F:
1201 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1202 trf->modulator_sys_clk_ctrl =
1203 (trf->modulator_sys_clk_ctrl & 0xf8) |
1204 TRF7970A_MODULATOR_DEPTH_ASK10;
1205 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1206 break;
1207 case NFC_DIGITAL_RF_TECH_ISO15693:
1208 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1209 trf->modulator_sys_clk_ctrl =
1210 (trf->modulator_sys_clk_ctrl & 0xf8) |
1211 TRF7970A_MODULATOR_DEPTH_OOK;
1212 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1213 break;
1214 default:
1215 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1216 return -EINVAL;
1217 }
1218
1219 trf->technology = tech;
1220
1221 /* If in initiator mode and not changing the RF tech due to a
1222 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1223 * trf7970a_init()), clear the NFC Target Detection Level register
1224 * due to erratum.
1225 */
1226 if (trf->iso_ctrl == 0xff)
1227 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1228
1229 return ret;
1230}
1231
1232static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1233{
1234 int ret;
1235 u8 rssi;
1236
1237 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1238 trf->chip_status_ctrl |
1239 TRF7970A_CHIP_STATUS_REC_ON);
1240 if (ret)
1241 return ret;
1242
1243 ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1244 if (ret)
1245 return ret;
1246
1247 usleep_range(50, 60);
1248
1249 ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1250 if (ret)
1251 return ret;
1252
1253 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1254 trf->chip_status_ctrl);
1255 if (ret)
1256 return ret;
1257
1258 if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1259 *is_rf_field = true;
1260 else
1261 *is_rf_field = false;
1262
1263 return 0;
1264}
1265
1266static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1267{
1268 u8 iso_ctrl = trf->iso_ctrl_tech;
1269 bool is_rf_field = false;
1270 int ret;
1271
1272 dev_dbg(trf->dev, "framing: %d\n", framing);
1273
1274 switch (framing) {
1275 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1276 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1277 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1278 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1279 break;
1280 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1281 case NFC_DIGITAL_FRAMING_NFCA_T4T:
1282 case NFC_DIGITAL_FRAMING_NFCB:
1283 case NFC_DIGITAL_FRAMING_NFCB_T4T:
1284 case NFC_DIGITAL_FRAMING_NFCF:
1285 case NFC_DIGITAL_FRAMING_NFCF_T3T:
1286 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1287 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1288 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1289 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1290 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1291 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1292 break;
1293 case NFC_DIGITAL_FRAMING_NFCA_T2T:
1294 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1295 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1296 break;
1297 default:
1298 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1299 return -EINVAL;
1300 }
1301
1302 trf->framing = framing;
1303
1304 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1305 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1306 if (ret)
1307 return ret;
1308
1309 if (is_rf_field)
1310 return -EBUSY;
1311 }
1312
1313 if (iso_ctrl != trf->iso_ctrl) {
1314 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1315 if (ret)
1316 return ret;
1317
1318 trf->iso_ctrl = iso_ctrl;
1319
1320 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1321 trf->modulator_sys_clk_ctrl);
1322 if (ret)
1323 return ret;
1324 }
1325
1326 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1327 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1328 trf->chip_status_ctrl |
1329 TRF7970A_CHIP_STATUS_RF_ON);
1330 if (ret)
1331 return ret;
1332
1333 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1334
1335 usleep_range(trf->guard_time, trf->guard_time + 1000);
1336 }
1337
1338 return 0;
1339}
1340
1341static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1342 int param)
1343{
1344 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1345 int ret;
1346
1347 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1348
1349 mutex_lock(&trf->lock);
1350
1351 trf->is_initiator = true;
1352
1353 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1354 (trf->state == TRF7970A_ST_RF_OFF)) {
1355 ret = trf7970a_switch_rf_on(trf);
1356 if (ret)
1357 goto err_unlock;
1358 }
1359
1360 switch (type) {
1361 case NFC_DIGITAL_CONFIG_RF_TECH:
1362 ret = trf7970a_in_config_rf_tech(trf, param);
1363 break;
1364 case NFC_DIGITAL_CONFIG_FRAMING:
1365 ret = trf7970a_in_config_framing(trf, param);
1366 break;
1367 default:
1368 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1369 ret = -EINVAL;
1370 }
1371
1372err_unlock:
1373 mutex_unlock(&trf->lock);
1374 return ret;
1375}
1376
1377static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1378{
1379 switch (cmd) {
1380 case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1381 case ISO15693_CMD_LOCK_BLOCK:
1382 case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1383 case ISO15693_CMD_WRITE_AFI:
1384 case ISO15693_CMD_LOCK_AFI:
1385 case ISO15693_CMD_WRITE_DSFID:
1386 case ISO15693_CMD_LOCK_DSFID:
1387 return 1;
1388 break;
1389 default:
1390 return 0;
1391 }
1392}
1393
1394static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1395{
1396 u8 *req = skb->data;
1397 u8 special_fcn_reg1, iso_ctrl;
1398 int ret;
1399
1400 trf->issue_eof = false;
1401
1402 /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1403 * special functions register 1 is cleared; otherwise, its a write or
1404 * sector select command and '4_bit_RX' must be set.
1405 *
1406 * When issuing an ISO 15693 command, inspect the flags byte to see
1407 * what speed to use. Also, remember if the OPTION flag is set on
1408 * a Type 5 write or lock command so the driver will know that it
1409 * has to send an EOF in order to get a response.
1410 */
1411 if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1412 (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1413 if (req[0] == NFC_T2T_CMD_READ)
1414 special_fcn_reg1 = 0;
1415 else
1416 special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1417
1418 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1419 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1420 special_fcn_reg1);
1421 if (ret)
1422 return ret;
1423
1424 trf->special_fcn_reg1 = special_fcn_reg1;
1425 }
1426 } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1427 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1428
1429 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1430 case 0x00:
1431 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1432 break;
1433 case ISO15693_REQ_FLAG_SUB_CARRIER:
1434 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1435 break;
1436 case ISO15693_REQ_FLAG_DATA_RATE:
1437 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1438 break;
1439 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1440 ISO15693_REQ_FLAG_DATA_RATE):
1441 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1442 break;
1443 }
1444
1445 if (iso_ctrl != trf->iso_ctrl) {
1446 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1447 if (ret)
1448 return ret;
1449
1450 trf->iso_ctrl = iso_ctrl;
1451 }
1452
1453 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1454 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1455 (req[0] & ISO15693_REQ_FLAG_OPTION))
1456 trf->issue_eof = true;
1457 }
1458
1459 return 0;
1460}
1461
1462static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1463 struct sk_buff *skb, u16 timeout,
1464 nfc_digital_cmd_complete_t cb, void *arg)
1465{
1466 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1467 u8 prefix[5];
1468 unsigned int len;
1469 int ret;
1470 u8 status;
1471
1472 dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1473 trf->state, timeout, skb->len);
1474
1475 if (skb->len > TRF7970A_TX_MAX)
1476 return -EINVAL;
1477
1478 mutex_lock(&trf->lock);
1479
1480 if ((trf->state != TRF7970A_ST_IDLE) &&
1481 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1482 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1483 trf->state);
1484 ret = -EIO;
1485 goto out_err;
1486 }
1487
1488 if (trf->aborting) {
1489 dev_dbg(trf->dev, "Abort process complete\n");
1490 trf->aborting = false;
1491 ret = -ECANCELED;
1492 goto out_err;
1493 }
1494
1495 if (timeout) {
1496 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1497 GFP_KERNEL);
1498 if (!trf->rx_skb) {
1499 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1500 ret = -ENOMEM;
1501 goto out_err;
1502 }
1503 }
1504
1505 if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1506 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1507 if (ret)
1508 goto out_err;
1509
1510 trf->state = TRF7970A_ST_IDLE;
1511 }
1512
1513 if (trf->is_initiator) {
1514 ret = trf7970a_per_cmd_config(trf, skb);
1515 if (ret)
1516 goto out_err;
1517 }
1518
1519 trf->ddev = ddev;
1520 trf->tx_skb = skb;
1521 trf->cb = cb;
1522 trf->cb_arg = arg;
1523 trf->timeout = timeout;
1524 trf->ignore_timeout = false;
1525
1526 len = skb->len;
1527
1528 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1529 * on what the current framing is, the address of the TX length byte 1
1530 * register (0x1d), and the 2 byte length of the data to be transmitted.
1531 * That totals 5 bytes.
1532 */
1533 prefix[0] = TRF7970A_CMD_BIT_CTRL |
1534 TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1535 prefix[1] = TRF7970A_CMD_BIT_CTRL |
1536 TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1537 prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1538
1539 if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1540 prefix[3] = 0x00;
1541 prefix[4] = 0x0f; /* 7 bits */
1542 } else {
1543 prefix[3] = (len & 0xf00) >> 4;
1544 prefix[3] |= ((len & 0xf0) >> 4);
1545 prefix[4] = ((len & 0x0f) << 4);
1546 }
1547
1548 len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1549
1550 /* Clear possible spurious interrupt */
1551 ret = trf7970a_read_irqstatus(trf, &status);
1552 if (ret)
1553 goto out_err;
1554
1555 ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1556 if (ret) {
1557 kfree_skb(trf->rx_skb);
1558 trf->rx_skb = NULL;
1559 }
1560
1561out_err:
1562 mutex_unlock(&trf->lock);
1563 return ret;
1564}
1565
1566static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1567{
1568 int ret = 0;
1569
1570 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1571
1572 switch (tech) {
1573 case NFC_DIGITAL_RF_TECH_106A:
1574 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1575 TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1576 trf->modulator_sys_clk_ctrl =
1577 (trf->modulator_sys_clk_ctrl & 0xf8) |
1578 TRF7970A_MODULATOR_DEPTH_OOK;
1579 break;
1580 case NFC_DIGITAL_RF_TECH_212F:
1581 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1582 TRF7970A_ISO_CTRL_NFC_NFCF_212;
1583 trf->modulator_sys_clk_ctrl =
1584 (trf->modulator_sys_clk_ctrl & 0xf8) |
1585 TRF7970A_MODULATOR_DEPTH_ASK10;
1586 break;
1587 case NFC_DIGITAL_RF_TECH_424F:
1588 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1589 TRF7970A_ISO_CTRL_NFC_NFCF_424;
1590 trf->modulator_sys_clk_ctrl =
1591 (trf->modulator_sys_clk_ctrl & 0xf8) |
1592 TRF7970A_MODULATOR_DEPTH_ASK10;
1593 break;
1594 default:
1595 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1596 return -EINVAL;
1597 }
1598
1599 trf->technology = tech;
1600
1601 /* Normally we write the ISO_CTRL register in
1602 * trf7970a_tg_config_framing() because the framing can change
1603 * the value written. However, when sending a PSL RES,
1604 * digital_tg_send_psl_res_complete() doesn't call
1605 * trf7970a_tg_config_framing() so we must write the register
1606 * here.
1607 */
1608 if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1609 (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1610 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1611 trf->iso_ctrl_tech);
1612
1613 trf->iso_ctrl = trf->iso_ctrl_tech;
1614 }
1615
1616 return ret;
1617}
1618
1619/* Since this is a target routine, several of the framing calls are
1620 * made between receiving the request and sending the response so they
1621 * should take effect until after the response is sent. This is accomplished
1622 * by skipping the ISO_CTRL register write here and doing it in the interrupt
1623 * handler.
1624 */
1625static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1626{
1627 u8 iso_ctrl = trf->iso_ctrl_tech;
1628 int ret;
1629
1630 dev_dbg(trf->dev, "framing: %d\n", framing);
1631
1632 switch (framing) {
1633 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1634 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1635 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1636 break;
1637 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1638 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1639 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1640 /* These ones are applied in the interrupt handler */
1641 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1642 break;
1643 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1644 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1645 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1646 break;
1647 case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1648 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1649 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1650 break;
1651 default:
1652 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1653 return -EINVAL;
1654 }
1655
1656 trf->framing = framing;
1657
1658 if (iso_ctrl != trf->iso_ctrl) {
1659 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1660 if (ret)
1661 return ret;
1662
1663 trf->iso_ctrl = iso_ctrl;
1664
1665 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1666 trf->modulator_sys_clk_ctrl);
1667 if (ret)
1668 return ret;
1669 }
1670
1671 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1672 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1673 trf->chip_status_ctrl |
1674 TRF7970A_CHIP_STATUS_RF_ON);
1675 if (ret)
1676 return ret;
1677
1678 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1679 }
1680
1681 return 0;
1682}
1683
1684static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1685 int param)
1686{
1687 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1688 int ret;
1689
1690 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1691
1692 mutex_lock(&trf->lock);
1693
1694 trf->is_initiator = false;
1695
1696 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1697 (trf->state == TRF7970A_ST_RF_OFF)) {
1698 ret = trf7970a_switch_rf_on(trf);
1699 if (ret)
1700 goto err_unlock;
1701 }
1702
1703 switch (type) {
1704 case NFC_DIGITAL_CONFIG_RF_TECH:
1705 ret = trf7970a_tg_config_rf_tech(trf, param);
1706 break;
1707 case NFC_DIGITAL_CONFIG_FRAMING:
1708 ret = trf7970a_tg_config_framing(trf, param);
1709 break;
1710 default:
1711 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1712 ret = -EINVAL;
1713 }
1714
1715err_unlock:
1716 mutex_unlock(&trf->lock);
1717 return ret;
1718}
1719
1720static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1721 nfc_digital_cmd_complete_t cb, void *arg,
1722 bool mode_detect)
1723{
1724 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1725 int ret;
1726
1727 mutex_lock(&trf->lock);
1728
1729 if ((trf->state != TRF7970A_ST_IDLE) &&
1730 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1731 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1732 trf->state);
1733 ret = -EIO;
1734 goto out_err;
1735 }
1736
1737 if (trf->aborting) {
1738 dev_dbg(trf->dev, "Abort process complete\n");
1739 trf->aborting = false;
1740 ret = -ECANCELED;
1741 goto out_err;
1742 }
1743
1744 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1745 GFP_KERNEL);
1746 if (!trf->rx_skb) {
1747 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1748 ret = -ENOMEM;
1749 goto out_err;
1750 }
1751
1752 ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1753 TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1754 TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1755 TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1756 TRF7970A_RX_SPECIAL_SETTINGS_C212);
1757 if (ret)
1758 goto out_err;
1759
1760 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1761 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1762 if (ret)
1763 goto out_err;
1764
1765 ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1766 TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1767 if (ret)
1768 goto out_err;
1769
1770 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1771 TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1772 if (ret)
1773 goto out_err;
1774
1775 trf->ddev = ddev;
1776 trf->cb = cb;
1777 trf->cb_arg = arg;
1778 trf->timeout = timeout;
1779 trf->ignore_timeout = false;
1780
1781 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1782 if (ret)
1783 goto out_err;
1784
1785 trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1786 TRF7970A_ST_LISTENING;
1787
1788 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1789
1790out_err:
1791 mutex_unlock(&trf->lock);
1792 return ret;
1793}
1794
1795static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1796 nfc_digital_cmd_complete_t cb, void *arg)
1797{
1798 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1799
1800 dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1801 trf->state, timeout);
1802
1803 return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1804}
1805
1806static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1807 u16 timeout, nfc_digital_cmd_complete_t cb,
1808 void *arg)
1809{
1810 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1811 int ret;
1812
1813 dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1814 trf->state, timeout);
1815
1816 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1817 NFC_DIGITAL_RF_TECH_106A);
1818 if (ret)
1819 return ret;
1820
1821 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1822 NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1823 if (ret)
1824 return ret;
1825
1826 return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1827}
1828
1829static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1830{
1831 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1832
1833 dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1834 trf->state, trf->md_rf_tech);
1835
1836 *rf_tech = trf->md_rf_tech;
1837
1838 return 0;
1839}
1840
1841static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1842{
1843 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1844
1845 dev_dbg(trf->dev, "Abort process initiated\n");
1846
1847 mutex_lock(&trf->lock);
1848
1849 switch (trf->state) {
1850 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1851 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1852 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1853 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1854 trf->aborting = true;
1855 break;
1856 case TRF7970A_ST_LISTENING:
1857 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1858 trf7970a_send_err_upstream(trf, -ECANCELED);
1859 dev_dbg(trf->dev, "Abort process complete\n");
1860 break;
1861 default:
1862 break;
1863 }
1864
1865 mutex_unlock(&trf->lock);
1866}
1867
1868static struct nfc_digital_ops trf7970a_nfc_ops = {
1869 .in_configure_hw = trf7970a_in_configure_hw,
1870 .in_send_cmd = trf7970a_send_cmd,
1871 .tg_configure_hw = trf7970a_tg_configure_hw,
1872 .tg_send_cmd = trf7970a_send_cmd,
1873 .tg_listen = trf7970a_tg_listen,
1874 .tg_listen_md = trf7970a_tg_listen_md,
1875 .tg_get_rf_tech = trf7970a_tg_get_rf_tech,
1876 .switch_rf = trf7970a_switch_rf,
1877 .abort_cmd = trf7970a_abort_cmd,
1878};
1879
1880static int trf7970a_power_up(struct trf7970a *trf)
1881{
1882 int ret;
1883
1884 dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1885
1886 if (trf->state != TRF7970A_ST_PWR_OFF)
1887 return 0;
1888
1889 ret = regulator_enable(trf->regulator);
1890 if (ret) {
1891 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1892 return ret;
1893 }
1894
1895 usleep_range(5000, 6000);
1896
1897 if (trf->en2_gpiod &&
1898 !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1899 gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1900 usleep_range(1000, 2000);
1901 }
1902
1903 gpiod_set_value_cansleep(trf->en_gpiod, 1);
1904
1905 usleep_range(20000, 21000);
1906
1907 trf->state = TRF7970A_ST_RF_OFF;
1908
1909 return 0;
1910}
1911
1912static int trf7970a_power_down(struct trf7970a *trf)
1913{
1914 int ret;
1915
1916 dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1917
1918 if (trf->state == TRF7970A_ST_PWR_OFF)
1919 return 0;
1920
1921 if (trf->state != TRF7970A_ST_RF_OFF) {
1922 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1923 trf->state);
1924 return -EBUSY;
1925 }
1926
1927 gpiod_set_value_cansleep(trf->en_gpiod, 0);
1928
1929 if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1930 gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1931
1932 ret = regulator_disable(trf->regulator);
1933 if (ret)
1934 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1935 ret);
1936
1937 trf->state = TRF7970A_ST_PWR_OFF;
1938
1939 return ret;
1940}
1941
1942static int trf7970a_startup(struct trf7970a *trf)
1943{
1944 int ret;
1945
1946 ret = trf7970a_power_up(trf);
1947 if (ret)
1948 return ret;
1949
1950 pm_runtime_set_active(trf->dev);
1951 pm_runtime_enable(trf->dev);
1952 pm_runtime_mark_last_busy(trf->dev);
1953
1954 return 0;
1955}
1956
1957static void trf7970a_shutdown(struct trf7970a *trf)
1958{
1959 switch (trf->state) {
1960 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1961 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1962 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1963 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1964 case TRF7970A_ST_LISTENING:
1965 trf7970a_send_err_upstream(trf, -ECANCELED);
1966 /* FALLTHROUGH */
1967 case TRF7970A_ST_IDLE:
1968 case TRF7970A_ST_IDLE_RX_BLOCKED:
1969 trf7970a_switch_rf_off(trf);
1970 break;
1971 default:
1972 break;
1973 }
1974
1975 pm_runtime_disable(trf->dev);
1976 pm_runtime_set_suspended(trf->dev);
1977
1978 trf7970a_power_down(trf);
1979}
1980
1981static int trf7970a_get_autosuspend_delay(struct device_node *np)
1982{
1983 int autosuspend_delay, ret;
1984
1985 ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1986 if (ret)
1987 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1988
1989 return autosuspend_delay;
1990}
1991
1992static int trf7970a_probe(struct spi_device *spi)
1993{
1994 struct device_node *np = spi->dev.of_node;
1995 struct trf7970a *trf;
1996 int uvolts, autosuspend_delay, ret;
1997 u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1998
1999 if (!np) {
2000 dev_err(&spi->dev, "No Device Tree entry\n");
2001 return -EINVAL;
2002 }
2003
2004 trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2005 if (!trf)
2006 return -ENOMEM;
2007
2008 trf->state = TRF7970A_ST_PWR_OFF;
2009 trf->dev = &spi->dev;
2010 trf->spi = spi;
2011
2012 spi->mode = SPI_MODE_1;
2013 spi->bits_per_word = 8;
2014
2015 ret = spi_setup(spi);
2016 if (ret < 0) {
2017 dev_err(trf->dev, "Can't set up SPI Communication\n");
2018 return ret;
2019 }
2020
2021 if (of_property_read_bool(np, "irq-status-read-quirk"))
2022 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2023
2024 /* There are two enable pins - only EN must be present in the DT */
2025 trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2026 GPIOD_OUT_LOW);
2027 if (IS_ERR(trf->en_gpiod)) {
2028 dev_err(trf->dev, "No EN GPIO property\n");
2029 return PTR_ERR(trf->en_gpiod);
2030 }
2031
2032 trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2033 GPIOD_OUT_LOW);
2034 if (!trf->en2_gpiod) {
2035 dev_info(trf->dev, "No EN2 GPIO property\n");
2036 } else if (IS_ERR(trf->en2_gpiod)) {
2037 dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2038 PTR_ERR(trf->en2_gpiod));
2039 return PTR_ERR(trf->en2_gpiod);
2040 } else if (of_property_read_bool(np, "en2-rf-quirk")) {
2041 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2042 }
2043
2044 of_property_read_u32(np, "clock-frequency", &clk_freq);
2045 if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2046 (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2047 dev_err(trf->dev,
2048 "clock-frequency (%u Hz) unsupported\n", clk_freq);
2049 return -EINVAL;
2050 }
2051
2052 if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2053 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2054 dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2055 } else {
2056 trf->modulator_sys_clk_ctrl = 0;
2057 }
2058
2059 ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2060 trf7970a_irq,
2061 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2062 "trf7970a", trf);
2063 if (ret) {
2064 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2065 return ret;
2066 }
2067
2068 mutex_init(&trf->lock);
2069 INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2070
2071 trf->regulator = devm_regulator_get(&spi->dev, "vin");
2072 if (IS_ERR(trf->regulator)) {
2073 ret = PTR_ERR(trf->regulator);
2074 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2075 goto err_destroy_lock;
2076 }
2077
2078 ret = regulator_enable(trf->regulator);
2079 if (ret) {
2080 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2081 goto err_destroy_lock;
2082 }
2083
2084 uvolts = regulator_get_voltage(trf->regulator);
2085 if (uvolts > 4000000)
2086 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2087
2088 trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2089 if (IS_ERR(trf->regulator)) {
2090 ret = PTR_ERR(trf->regulator);
2091 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2092 goto err_destroy_lock;
2093 }
2094
2095 ret = regulator_enable(trf->regulator);
2096 if (ret) {
2097 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2098 goto err_destroy_lock;
2099 }
2100
2101 if (regulator_get_voltage(trf->regulator) == 1800000) {
2102 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2103 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2104 }
2105
2106 trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2107 TRF7970A_SUPPORTED_PROTOCOLS,
2108 NFC_DIGITAL_DRV_CAPS_IN_CRC |
2109 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2110 0);
2111 if (!trf->ddev) {
2112 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2113 ret = -ENOMEM;
2114 goto err_disable_regulator;
2115 }
2116
2117 nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2118 nfc_digital_set_drvdata(trf->ddev, trf);
2119 spi_set_drvdata(spi, trf);
2120
2121 autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2122
2123 pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2124 pm_runtime_use_autosuspend(trf->dev);
2125
2126 ret = trf7970a_startup(trf);
2127 if (ret)
2128 goto err_free_ddev;
2129
2130 ret = nfc_digital_register_device(trf->ddev);
2131 if (ret) {
2132 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2133 ret);
2134 goto err_shutdown;
2135 }
2136
2137 return 0;
2138
2139err_shutdown:
2140 trf7970a_shutdown(trf);
2141err_free_ddev:
2142 nfc_digital_free_device(trf->ddev);
2143err_disable_regulator:
2144 regulator_disable(trf->regulator);
2145err_destroy_lock:
2146 mutex_destroy(&trf->lock);
2147 return ret;
2148}
2149
2150static int trf7970a_remove(struct spi_device *spi)
2151{
2152 struct trf7970a *trf = spi_get_drvdata(spi);
2153
2154 mutex_lock(&trf->lock);
2155
2156 trf7970a_shutdown(trf);
2157
2158 mutex_unlock(&trf->lock);
2159
2160 nfc_digital_unregister_device(trf->ddev);
2161 nfc_digital_free_device(trf->ddev);
2162
2163 regulator_disable(trf->regulator);
2164
2165 mutex_destroy(&trf->lock);
2166
2167 return 0;
2168}
2169
2170#ifdef CONFIG_PM_SLEEP
2171static int trf7970a_suspend(struct device *dev)
2172{
2173 struct spi_device *spi = to_spi_device(dev);
2174 struct trf7970a *trf = spi_get_drvdata(spi);
2175
2176 dev_dbg(dev, "Suspend\n");
2177
2178 mutex_lock(&trf->lock);
2179
2180 trf7970a_shutdown(trf);
2181
2182 mutex_unlock(&trf->lock);
2183
2184 return 0;
2185}
2186
2187static int trf7970a_resume(struct device *dev)
2188{
2189 struct spi_device *spi = to_spi_device(dev);
2190 struct trf7970a *trf = spi_get_drvdata(spi);
2191 int ret;
2192
2193 dev_dbg(dev, "Resume\n");
2194
2195 mutex_lock(&trf->lock);
2196
2197 ret = trf7970a_startup(trf);
2198
2199 mutex_unlock(&trf->lock);
2200
2201 return ret;
2202}
2203#endif
2204
2205#ifdef CONFIG_PM
2206static int trf7970a_pm_runtime_suspend(struct device *dev)
2207{
2208 struct spi_device *spi = to_spi_device(dev);
2209 struct trf7970a *trf = spi_get_drvdata(spi);
2210 int ret;
2211
2212 dev_dbg(dev, "Runtime suspend\n");
2213
2214 mutex_lock(&trf->lock);
2215
2216 ret = trf7970a_power_down(trf);
2217
2218 mutex_unlock(&trf->lock);
2219
2220 return ret;
2221}
2222
2223static int trf7970a_pm_runtime_resume(struct device *dev)
2224{
2225 struct spi_device *spi = to_spi_device(dev);
2226 struct trf7970a *trf = spi_get_drvdata(spi);
2227 int ret;
2228
2229 dev_dbg(dev, "Runtime resume\n");
2230
2231 ret = trf7970a_power_up(trf);
2232 if (!ret)
2233 pm_runtime_mark_last_busy(dev);
2234
2235 return ret;
2236}
2237#endif
2238
2239static const struct dev_pm_ops trf7970a_pm_ops = {
2240 SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2241 SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2242 trf7970a_pm_runtime_resume, NULL)
2243};
2244
2245static const struct of_device_id trf7970a_of_match[] = {
2246 {.compatible = "ti,trf7970a",},
2247 {},
2248};
2249
2250MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2251
2252static const struct spi_device_id trf7970a_id_table[] = {
2253 {"trf7970a", 0},
2254 {}
2255};
2256
2257MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2258
2259static struct spi_driver trf7970a_spi_driver = {
2260 .probe = trf7970a_probe,
2261 .remove = trf7970a_remove,
2262 .id_table = trf7970a_id_table,
2263 .driver = {
2264 .name = "trf7970a",
2265 .of_match_table = of_match_ptr(trf7970a_of_match),
2266 .pm = &trf7970a_pm_ops,
2267 },
2268};
2269
2270module_spi_driver(trf7970a_spi_driver);
2271
2272MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2273MODULE_LICENSE("GPL v2");
2274MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");