Loading...
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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI TRF7970a RFID/NFC Transceiver Driver
4 *
5 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
6 *
7 * Author: Erick Macias <emacias@ti.com>
8 * Author: Felipe Balbi <balbi@ti.com>
9 * Author: Mark A. Greer <mgreer@animalcreek.com>
10 */
11
12#include <linux/module.h>
13#include <linux/device.h>
14#include <linux/netdevice.h>
15#include <linux/interrupt.h>
16#include <linux/pm_runtime.h>
17#include <linux/nfc.h>
18#include <linux/skbuff.h>
19#include <linux/delay.h>
20#include <linux/gpio/consumer.h>
21#include <linux/of.h>
22#include <linux/spi/spi.h>
23#include <linux/regulator/consumer.h>
24
25#include <net/nfc/nfc.h>
26#include <net/nfc/digital.h>
27
28/* There are 3 ways the host can communicate with the trf7970a:
29 * parallel mode, SPI with Slave Select (SS) mode, and SPI without
30 * SS mode. The driver only supports the two SPI modes.
31 *
32 * The trf7970a is very timing sensitive and the VIN, EN2, and EN
33 * pins must asserted in that order and with specific delays in between.
34 * The delays used in the driver were provided by TI and have been
35 * confirmed to work with this driver. There is a bug with the current
36 * version of the trf7970a that requires that EN2 remain low no matter
37 * what. If it goes high, it will generate an RF field even when in
38 * passive target mode. TI has indicated that the chip will work okay
39 * when EN2 is left low. The 'en2-rf-quirk' device tree property
40 * indicates that trf7970a currently being used has the erratum and
41 * that EN2 must be kept low.
42 *
43 * Timeouts are implemented using the delayed workqueue kernel facility.
44 * Timeouts are required so things don't hang when there is no response
45 * from the trf7970a (or tag). Using this mechanism creates a race with
46 * interrupts, however. That is, an interrupt and a timeout could occur
47 * closely enough together that one is blocked by the mutex while the other
48 * executes. When the timeout handler executes first and blocks the
49 * interrupt handler, it will eventually set the state to IDLE so the
50 * interrupt handler will check the state and exit with no harm done.
51 * When the interrupt handler executes first and blocks the timeout handler,
52 * the cancel_delayed_work() call will know that it didn't cancel the
53 * work item (i.e., timeout) and will return zero. That return code is
54 * used by the timer handler to indicate that it should ignore the timeout
55 * once its unblocked.
56 *
57 * Aborting an active command isn't as simple as it seems because the only
58 * way to abort a command that's already been sent to the tag is so turn
59 * off power to the tag. If we do that, though, we'd have to go through
60 * the entire anticollision procedure again but the digital layer doesn't
61 * support that. So, if an abort is received before trf7970a_send_cmd()
62 * has sent the command to the tag, it simply returns -ECANCELED. If the
63 * command has already been sent to the tag, then the driver continues
64 * normally and recieves the response data (or error) but just before
65 * sending the data upstream, it frees the rx_skb and sends -ECANCELED
66 * upstream instead. If the command failed, that error will be sent
67 * upstream.
68 *
69 * When recieving data from a tag and the interrupt status register has
70 * only the SRX bit set, it means that all of the data has been received
71 * (once what's in the fifo has been read). However, depending on timing
72 * an interrupt status with only the SRX bit set may not be recived. In
73 * those cases, the timeout mechanism is used to wait 20 ms in case more
74 * data arrives. After 20 ms, it is assumed that all of the data has been
75 * received and the accumulated rx data is sent upstream. The
76 * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
77 * (i.e., it indicates that some data has been received but we're not sure
78 * if there is more coming so a timeout in this state means all data has
79 * been received and there isn't an error). The delay is 20 ms since delays
80 * of ~16 ms have been observed during testing.
81 *
82 * When transmitting a frame larger than the FIFO size (127 bytes), the
83 * driver will wait 20 ms for the FIFO to drain past the low-watermark
84 * and generate an interrupt. The low-watermark set to 32 bytes so the
85 * interrupt should fire after 127 - 32 = 95 bytes have been sent. At
86 * the lowest possible bit rate (6.62 kbps for 15693), it will take up
87 * to ~14.35 ms so 20 ms is used for the timeout.
88 *
89 * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
90 * Having only 4 bits in the FIFO won't normally generate an interrupt so
91 * driver enables the '4_bit_RX' bit of the Special Functions register 1
92 * to cause an interrupt in that case. Leaving that bit for a read command
93 * messes up the data returned so it is only enabled when the framing is
94 * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
95 * Unfortunately, that means that the driver has to peek into tx frames
96 * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by
97 * the trf7970a_per_cmd_config() routine.
98 *
99 * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
100 * frequencies and whether to use low or high data rates in the flags byte
101 * of the frame. This means that the driver has to peek at all 15693 frames
102 * to determine what speed to set the communication to. In addition, write
103 * and lock commands use the OPTION flag to indicate that an EOF must be
104 * sent to the tag before it will send its response. So the driver has to
105 * examine all frames for that reason too.
106 *
107 * It is unclear how long to wait before sending the EOF. According to the
108 * Note under Table 1-1 in section 1.6 of
109 * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
110 * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
111 * enough so 20 ms is used. So the timer is set to 40 ms - 20 ms to drain
112 * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
113 * ensure the wait is long enough before sending the EOF. This seems to work
114 * reliably.
115 */
116
117#define TRF7970A_SUPPORTED_PROTOCOLS \
118 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
119 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
120 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
121
122#define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */
123#define TRF7970A_13MHZ_CLOCK_FREQUENCY 13560000
124#define TRF7970A_27MHZ_CLOCK_FREQUENCY 27120000
125
126#define TRF7970A_RX_SKB_ALLOC_SIZE 256
127
128#define TRF7970A_FIFO_SIZE 127
129
130/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
131#define TRF7970A_TX_MAX (4096 - 1)
132
133#define TRF7970A_WAIT_FOR_TX_IRQ 20
134#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20
135#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 20
136#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40
137
138/* Guard times for various RF technologies (in us) */
139#define TRF7970A_GUARD_TIME_NFCA 5000
140#define TRF7970A_GUARD_TIME_NFCB 5000
141#define TRF7970A_GUARD_TIME_NFCF 20000
142#define TRF7970A_GUARD_TIME_15693 1000
143
144/* Quirks */
145/* Erratum: When reading IRQ Status register on trf7970a, we must issue a
146 * read continuous command for IRQ Status and Collision Position registers.
147 */
148#define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0)
149#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1)
150
151/* Direct commands */
152#define TRF7970A_CMD_IDLE 0x00
153#define TRF7970A_CMD_SOFT_INIT 0x03
154#define TRF7970A_CMD_RF_COLLISION 0x04
155#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05
156#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06
157#define TRF7970A_CMD_FIFO_RESET 0x0f
158#define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10
159#define TRF7970A_CMD_TRANSMIT 0x11
160#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12
161#define TRF7970A_CMD_DELAY_TRANSMIT 0x13
162#define TRF7970A_CMD_EOF 0x14
163#define TRF7970A_CMD_CLOSE_SLOT 0x15
164#define TRF7970A_CMD_BLOCK_RX 0x16
165#define TRF7970A_CMD_ENABLE_RX 0x17
166#define TRF7970A_CMD_TEST_INT_RF 0x18
167#define TRF7970A_CMD_TEST_EXT_RF 0x19
168#define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a
169
170/* Bits determining whether its a direct command or register R/W,
171 * whether to use a continuous SPI transaction or not, and the actual
172 * direct cmd opcode or register address.
173 */
174#define TRF7970A_CMD_BIT_CTRL BIT(7)
175#define TRF7970A_CMD_BIT_RW BIT(6)
176#define TRF7970A_CMD_BIT_CONTINUOUS BIT(5)
177#define TRF7970A_CMD_BIT_OPCODE(opcode) ((opcode) & 0x1f)
178
179/* Registers addresses */
180#define TRF7970A_CHIP_STATUS_CTRL 0x00
181#define TRF7970A_ISO_CTRL 0x01
182#define TRF7970A_ISO14443B_TX_OPTIONS 0x02
183#define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
184#define TRF7970A_TX_TIMER_SETTING_H_BYTE 0x04
185#define TRF7970A_TX_TIMER_SETTING_L_BYTE 0x05
186#define TRF7970A_TX_PULSE_LENGTH_CTRL 0x06
187#define TRF7970A_RX_NO_RESPONSE_WAIT 0x07
188#define TRF7970A_RX_WAIT_TIME 0x08
189#define TRF7970A_MODULATOR_SYS_CLK_CTRL 0x09
190#define TRF7970A_RX_SPECIAL_SETTINGS 0x0a
191#define TRF7970A_REG_IO_CTRL 0x0b
192#define TRF7970A_IRQ_STATUS 0x0c
193#define TRF7970A_COLLISION_IRQ_MASK 0x0d
194#define TRF7970A_COLLISION_POSITION 0x0e
195#define TRF7970A_RSSI_OSC_STATUS 0x0f
196#define TRF7970A_SPECIAL_FCN_REG1 0x10
197#define TRF7970A_SPECIAL_FCN_REG2 0x11
198#define TRF7970A_RAM1 0x12
199#define TRF7970A_RAM2 0x13
200#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS 0x14
201#define TRF7970A_NFC_LOW_FIELD_LEVEL 0x16
202#define TRF7970A_NFCID1 0x17
203#define TRF7970A_NFC_TARGET_LEVEL 0x18
204#define TRF79070A_NFC_TARGET_PROTOCOL 0x19
205#define TRF7970A_TEST_REGISTER1 0x1a
206#define TRF7970A_TEST_REGISTER2 0x1b
207#define TRF7970A_FIFO_STATUS 0x1c
208#define TRF7970A_TX_LENGTH_BYTE1 0x1d
209#define TRF7970A_TX_LENGTH_BYTE2 0x1e
210#define TRF7970A_FIFO_IO_REGISTER 0x1f
211
212/* Chip Status Control Register Bits */
213#define TRF7970A_CHIP_STATUS_VRS5_3 BIT(0)
214#define TRF7970A_CHIP_STATUS_REC_ON BIT(1)
215#define TRF7970A_CHIP_STATUS_AGC_ON BIT(2)
216#define TRF7970A_CHIP_STATUS_PM_ON BIT(3)
217#define TRF7970A_CHIP_STATUS_RF_PWR BIT(4)
218#define TRF7970A_CHIP_STATUS_RF_ON BIT(5)
219#define TRF7970A_CHIP_STATUS_DIRECT BIT(6)
220#define TRF7970A_CHIP_STATUS_STBY BIT(7)
221
222/* ISO Control Register Bits */
223#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662 0x00
224#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662 0x01
225#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648 0x02
226#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
227#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a 0x04
228#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667 0x05
229#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669 0x06
230#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
231#define TRF7970A_ISO_CTRL_14443A_106 0x08
232#define TRF7970A_ISO_CTRL_14443A_212 0x09
233#define TRF7970A_ISO_CTRL_14443A_424 0x0a
234#define TRF7970A_ISO_CTRL_14443A_848 0x0b
235#define TRF7970A_ISO_CTRL_14443B_106 0x0c
236#define TRF7970A_ISO_CTRL_14443B_212 0x0d
237#define TRF7970A_ISO_CTRL_14443B_424 0x0e
238#define TRF7970A_ISO_CTRL_14443B_848 0x0f
239#define TRF7970A_ISO_CTRL_FELICA_212 0x1a
240#define TRF7970A_ISO_CTRL_FELICA_424 0x1b
241#define TRF7970A_ISO_CTRL_NFC_NFCA_106 0x01
242#define TRF7970A_ISO_CTRL_NFC_NFCF_212 0x02
243#define TRF7970A_ISO_CTRL_NFC_NFCF_424 0x03
244#define TRF7970A_ISO_CTRL_NFC_CE_14443A 0x00
245#define TRF7970A_ISO_CTRL_NFC_CE_14443B 0x01
246#define TRF7970A_ISO_CTRL_NFC_CE BIT(2)
247#define TRF7970A_ISO_CTRL_NFC_ACTIVE BIT(3)
248#define TRF7970A_ISO_CTRL_NFC_INITIATOR BIT(4)
249#define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE BIT(5)
250#define TRF7970A_ISO_CTRL_RFID BIT(5)
251#define TRF7970A_ISO_CTRL_DIR_MODE BIT(6)
252#define TRF7970A_ISO_CTRL_RX_CRC_N BIT(7) /* true == No CRC */
253
254#define TRF7970A_ISO_CTRL_RFID_SPEED_MASK 0x1f
255
256/* Modulator and SYS_CLK Control Register Bits */
257#define TRF7970A_MODULATOR_DEPTH(n) ((n) & 0x7)
258#define TRF7970A_MODULATOR_DEPTH_ASK10 (TRF7970A_MODULATOR_DEPTH(0))
259#define TRF7970A_MODULATOR_DEPTH_OOK (TRF7970A_MODULATOR_DEPTH(1))
260#define TRF7970A_MODULATOR_DEPTH_ASK7 (TRF7970A_MODULATOR_DEPTH(2))
261#define TRF7970A_MODULATOR_DEPTH_ASK8_5 (TRF7970A_MODULATOR_DEPTH(3))
262#define TRF7970A_MODULATOR_DEPTH_ASK13 (TRF7970A_MODULATOR_DEPTH(4))
263#define TRF7970A_MODULATOR_DEPTH_ASK16 (TRF7970A_MODULATOR_DEPTH(5))
264#define TRF7970A_MODULATOR_DEPTH_ASK22 (TRF7970A_MODULATOR_DEPTH(6))
265#define TRF7970A_MODULATOR_DEPTH_ASK30 (TRF7970A_MODULATOR_DEPTH(7))
266#define TRF7970A_MODULATOR_EN_ANA BIT(3)
267#define TRF7970A_MODULATOR_CLK(n) (((n) & 0x3) << 4)
268#define TRF7970A_MODULATOR_CLK_DISABLED (TRF7970A_MODULATOR_CLK(0))
269#define TRF7970A_MODULATOR_CLK_3_6 (TRF7970A_MODULATOR_CLK(1))
270#define TRF7970A_MODULATOR_CLK_6_13 (TRF7970A_MODULATOR_CLK(2))
271#define TRF7970A_MODULATOR_CLK_13_27 (TRF7970A_MODULATOR_CLK(3))
272#define TRF7970A_MODULATOR_EN_OOK BIT(6)
273#define TRF7970A_MODULATOR_27MHZ BIT(7)
274
275#define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
276#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR BIT(1)
277#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << 2)
278#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << 2)
279#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << 2)
280#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << 2)
281#define TRF7970A_RX_SPECIAL_SETTINGS_HBT BIT(4)
282#define TRF7970A_RX_SPECIAL_SETTINGS_M848 BIT(5)
283#define TRF7970A_RX_SPECIAL_SETTINGS_C424 BIT(6)
284#define TRF7970A_RX_SPECIAL_SETTINGS_C212 BIT(7)
285
286#define TRF7970A_REG_IO_CTRL_VRS(v) ((v) & 0x07)
287#define TRF7970A_REG_IO_CTRL_IO_LOW BIT(5)
288#define TRF7970A_REG_IO_CTRL_EN_EXT_PA BIT(6)
289#define TRF7970A_REG_IO_CTRL_AUTO_REG BIT(7)
290
291/* IRQ Status Register Bits */
292#define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
293#define TRF7970A_IRQ_STATUS_NFC_COL_ERROR BIT(0)
294#define TRF7970A_IRQ_STATUS_COL BIT(1)
295#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
296#define TRF7970A_IRQ_STATUS_NFC_RF BIT(2)
297#define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
298#define TRF7970A_IRQ_STATUS_NFC_SDD BIT(3)
299#define TRF7970A_IRQ_STATUS_CRC_ERROR BIT(4)
300#define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR BIT(4)
301#define TRF7970A_IRQ_STATUS_FIFO BIT(5)
302#define TRF7970A_IRQ_STATUS_SRX BIT(6)
303#define TRF7970A_IRQ_STATUS_TX BIT(7)
304
305#define TRF7970A_IRQ_STATUS_ERROR \
306 (TRF7970A_IRQ_STATUS_COL | \
307 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR | \
308 TRF7970A_IRQ_STATUS_PARITY_ERROR | \
309 TRF7970A_IRQ_STATUS_CRC_ERROR)
310
311#define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK (BIT(2) | BIT(1) | BIT(0))
312#define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK (BIT(5) | BIT(4) | BIT(3))
313#define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK BIT(6)
314
315#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6 BIT(0)
316#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL BIT(1)
317#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX BIT(2)
318#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE BIT(3)
319#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US BIT(4)
320#define TRF7970A_SPECIAL_FCN_REG1_PAR43 BIT(5)
321
322#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124 (0x0 << 2)
323#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120 (0x1 << 2)
324#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112 (0x2 << 2)
325#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 (0x3 << 2)
326#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4 0x0
327#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8 0x1
328#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16 0x2
329#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32 0x3
330
331#define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v) ((v) & 0x07)
332#define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS BIT(7)
333
334#define TRF7970A_NFC_TARGET_LEVEL_RFDET(v) ((v) & 0x07)
335#define TRF7970A_NFC_TARGET_LEVEL_HI_RF BIT(3)
336#define TRF7970A_NFC_TARGET_LEVEL_SDD_EN BIT(5)
337#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES (0x0 << 6)
338#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES (0x1 << 6)
339#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES (0x2 << 6)
340
341#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106 BIT(0)
342#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212 BIT(1)
343#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424 (BIT(0) | BIT(1))
344#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B BIT(2)
345#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 BIT(3)
346#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA BIT(4)
347#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L BIT(6)
348#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H BIT(7)
349
350#define TRF79070A_NFC_TARGET_PROTOCOL_106A \
351 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
352 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
353 TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 | \
354 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
355
356#define TRF79070A_NFC_TARGET_PROTOCOL_106B \
357 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
358 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
359 TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B | \
360 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
361
362#define TRF79070A_NFC_TARGET_PROTOCOL_212F \
363 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
364 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
365 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
366 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
367
368#define TRF79070A_NFC_TARGET_PROTOCOL_424F \
369 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
370 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
371 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
372 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
373
374#define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7)
375
376/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
377#define NFC_T2T_CMD_READ 0x30
378
379/* ISO 15693 commands codes */
380#define ISO15693_CMD_INVENTORY 0x01
381#define ISO15693_CMD_READ_SINGLE_BLOCK 0x20
382#define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21
383#define ISO15693_CMD_LOCK_BLOCK 0x22
384#define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23
385#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24
386#define ISO15693_CMD_SELECT 0x25
387#define ISO15693_CMD_RESET_TO_READY 0x26
388#define ISO15693_CMD_WRITE_AFI 0x27
389#define ISO15693_CMD_LOCK_AFI 0x28
390#define ISO15693_CMD_WRITE_DSFID 0x29
391#define ISO15693_CMD_LOCK_DSFID 0x2a
392#define ISO15693_CMD_GET_SYSTEM_INFO 0x2b
393#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
394
395/* ISO 15693 request and response flags */
396#define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0)
397#define ISO15693_REQ_FLAG_DATA_RATE BIT(1)
398#define ISO15693_REQ_FLAG_INVENTORY BIT(2)
399#define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3)
400#define ISO15693_REQ_FLAG_SELECT BIT(4)
401#define ISO15693_REQ_FLAG_AFI BIT(4)
402#define ISO15693_REQ_FLAG_ADDRESS BIT(5)
403#define ISO15693_REQ_FLAG_NB_SLOTS BIT(5)
404#define ISO15693_REQ_FLAG_OPTION BIT(6)
405
406#define ISO15693_REQ_FLAG_SPEED_MASK \
407 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
408
409enum trf7970a_state {
410 TRF7970A_ST_PWR_OFF,
411 TRF7970A_ST_RF_OFF,
412 TRF7970A_ST_IDLE,
413 TRF7970A_ST_IDLE_RX_BLOCKED,
414 TRF7970A_ST_WAIT_FOR_TX_FIFO,
415 TRF7970A_ST_WAIT_FOR_RX_DATA,
416 TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
417 TRF7970A_ST_WAIT_TO_ISSUE_EOF,
418 TRF7970A_ST_LISTENING,
419 TRF7970A_ST_LISTENING_MD,
420 TRF7970A_ST_MAX
421};
422
423struct trf7970a {
424 enum trf7970a_state state;
425 struct device *dev;
426 struct spi_device *spi;
427 struct regulator *regulator;
428 struct nfc_digital_dev *ddev;
429 u32 quirks;
430 bool is_initiator;
431 bool aborting;
432 struct sk_buff *tx_skb;
433 struct sk_buff *rx_skb;
434 nfc_digital_cmd_complete_t cb;
435 void *cb_arg;
436 u8 chip_status_ctrl;
437 u8 iso_ctrl;
438 u8 iso_ctrl_tech;
439 u8 modulator_sys_clk_ctrl;
440 u8 special_fcn_reg1;
441 u8 io_ctrl;
442 unsigned int guard_time;
443 int technology;
444 int framing;
445 u8 md_rf_tech;
446 u8 tx_cmd;
447 bool issue_eof;
448 struct gpio_desc *en_gpiod;
449 struct gpio_desc *en2_gpiod;
450 struct mutex lock;
451 unsigned int timeout;
452 bool ignore_timeout;
453 struct delayed_work timeout_work;
454};
455
456static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
457{
458 u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
459 int ret;
460
461 dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
462
463 ret = spi_write(trf->spi, &cmd, 1);
464 if (ret)
465 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
466 ret);
467 return ret;
468}
469
470static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
471{
472 u8 addr = TRF7970A_CMD_BIT_RW | reg;
473 int ret;
474
475 ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
476 if (ret)
477 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
478 ret);
479
480 dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
481
482 return ret;
483}
484
485static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
486 size_t len)
487{
488 u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
489 struct spi_transfer t[2];
490 struct spi_message m;
491 int ret;
492
493 dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
494
495 spi_message_init(&m);
496
497 memset(&t, 0, sizeof(t));
498
499 t[0].tx_buf = &addr;
500 t[0].len = sizeof(addr);
501 spi_message_add_tail(&t[0], &m);
502
503 t[1].rx_buf = buf;
504 t[1].len = len;
505 spi_message_add_tail(&t[1], &m);
506
507 ret = spi_sync(trf->spi, &m);
508 if (ret)
509 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
510 ret);
511 return ret;
512}
513
514static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
515{
516 u8 buf[2] = { reg, val };
517 int ret;
518
519 dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
520
521 ret = spi_write(trf->spi, buf, 2);
522 if (ret)
523 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
524 buf[0], buf[1], ret);
525
526 return ret;
527}
528
529static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
530{
531 int ret;
532 u8 buf[2];
533 u8 addr;
534
535 addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
536
537 if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
538 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
539 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
540 } else {
541 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
542 }
543
544 if (ret)
545 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
546 __func__, ret);
547 else
548 *status = buf[0];
549
550 return ret;
551}
552
553static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
554{
555 int ret;
556 u8 buf[2];
557 u8 addr;
558
559 addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
560 TRF7970A_CMD_BIT_CONTINUOUS;
561
562 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
563 if (ret)
564 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
565 __func__, ret);
566 else
567 *target_proto = buf[0];
568
569 return ret;
570}
571
572static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
573{
574 int ret;
575 u8 target_proto, tech;
576
577 ret = trf7970a_read_target_proto(trf, &target_proto);
578 if (ret)
579 return ret;
580
581 switch (target_proto) {
582 case TRF79070A_NFC_TARGET_PROTOCOL_106A:
583 tech = NFC_DIGITAL_RF_TECH_106A;
584 break;
585 case TRF79070A_NFC_TARGET_PROTOCOL_106B:
586 tech = NFC_DIGITAL_RF_TECH_106B;
587 break;
588 case TRF79070A_NFC_TARGET_PROTOCOL_212F:
589 tech = NFC_DIGITAL_RF_TECH_212F;
590 break;
591 case TRF79070A_NFC_TARGET_PROTOCOL_424F:
592 tech = NFC_DIGITAL_RF_TECH_424F;
593 break;
594 default:
595 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
596 __func__, target_proto);
597 return -EIO;
598 }
599
600 *rf_tech = tech;
601
602 return ret;
603}
604
605static void trf7970a_send_upstream(struct trf7970a *trf)
606{
607 dev_kfree_skb_any(trf->tx_skb);
608 trf->tx_skb = NULL;
609
610 if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
611 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
612 16, 1, trf->rx_skb->data, trf->rx_skb->len,
613 false);
614
615 trf->state = TRF7970A_ST_IDLE;
616
617 if (trf->aborting) {
618 dev_dbg(trf->dev, "Abort process complete\n");
619
620 if (!IS_ERR(trf->rx_skb)) {
621 kfree_skb(trf->rx_skb);
622 trf->rx_skb = ERR_PTR(-ECANCELED);
623 }
624
625 trf->aborting = false;
626 }
627
628 trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
629
630 trf->rx_skb = NULL;
631}
632
633static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
634{
635 dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
636
637 cancel_delayed_work(&trf->timeout_work);
638
639 kfree_skb(trf->rx_skb);
640 trf->rx_skb = ERR_PTR(errno);
641
642 trf7970a_send_upstream(trf);
643}
644
645static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
646 unsigned int len, const u8 *prefix,
647 unsigned int prefix_len)
648{
649 struct spi_transfer t[2];
650 struct spi_message m;
651 unsigned int timeout;
652 int ret;
653
654 print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
655 16, 1, skb->data, len, false);
656
657 spi_message_init(&m);
658
659 memset(&t, 0, sizeof(t));
660
661 t[0].tx_buf = prefix;
662 t[0].len = prefix_len;
663 spi_message_add_tail(&t[0], &m);
664
665 t[1].tx_buf = skb->data;
666 t[1].len = len;
667 spi_message_add_tail(&t[1], &m);
668
669 ret = spi_sync(trf->spi, &m);
670 if (ret) {
671 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
672 ret);
673 return ret;
674 }
675
676 skb_pull(skb, len);
677
678 if (skb->len > 0) {
679 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
680 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
681 } else {
682 if (trf->issue_eof) {
683 trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
684 timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
685 } else {
686 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
687
688 if (!trf->timeout)
689 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
690 else
691 timeout = trf->timeout;
692 }
693 }
694
695 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
696 trf->state);
697
698 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
699
700 return 0;
701}
702
703static void trf7970a_fill_fifo(struct trf7970a *trf)
704{
705 struct sk_buff *skb = trf->tx_skb;
706 unsigned int len;
707 int ret;
708 u8 fifo_bytes;
709 u8 prefix;
710
711 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
712 if (ret) {
713 trf7970a_send_err_upstream(trf, ret);
714 return;
715 }
716
717 dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
718
719 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
720
721 /* Calculate how much more data can be written to the fifo */
722 len = TRF7970A_FIFO_SIZE - fifo_bytes;
723 if (!len) {
724 schedule_delayed_work(&trf->timeout_work,
725 msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
726 return;
727 }
728
729 len = min(skb->len, len);
730
731 prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
732
733 ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
734 if (ret)
735 trf7970a_send_err_upstream(trf, ret);
736}
737
738static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
739{
740 struct sk_buff *skb = trf->rx_skb;
741 int ret;
742 u8 fifo_bytes;
743
744 if (status & TRF7970A_IRQ_STATUS_ERROR) {
745 trf7970a_send_err_upstream(trf, -EIO);
746 return;
747 }
748
749 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
750 if (ret) {
751 trf7970a_send_err_upstream(trf, ret);
752 return;
753 }
754
755 dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
756
757 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
758
759 if (!fifo_bytes)
760 goto no_rx_data;
761
762 if (fifo_bytes > skb_tailroom(skb)) {
763 skb = skb_copy_expand(skb, skb_headroom(skb),
764 max_t(int, fifo_bytes,
765 TRF7970A_RX_SKB_ALLOC_SIZE),
766 GFP_KERNEL);
767 if (!skb) {
768 trf7970a_send_err_upstream(trf, -ENOMEM);
769 return;
770 }
771
772 kfree_skb(trf->rx_skb);
773 trf->rx_skb = skb;
774 }
775
776 ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
777 skb_put(skb, fifo_bytes), fifo_bytes);
778 if (ret) {
779 trf7970a_send_err_upstream(trf, ret);
780 return;
781 }
782
783 /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
784 if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
785 (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
786 skb->data[0] >>= 4;
787 status = TRF7970A_IRQ_STATUS_SRX;
788 } else {
789 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
790
791 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
792 if (ret) {
793 trf7970a_send_err_upstream(trf, ret);
794 return;
795 }
796
797 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
798
799 /* If there are bytes in the FIFO, set status to '0' so
800 * the if stmt below doesn't fire and the driver will wait
801 * for the trf7970a to generate another RX interrupt.
802 */
803 if (fifo_bytes)
804 status = 0;
805 }
806
807no_rx_data:
808 if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
809 trf7970a_send_upstream(trf);
810 return;
811 }
812
813 dev_dbg(trf->dev, "Setting timeout for %d ms\n",
814 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
815
816 schedule_delayed_work(&trf->timeout_work,
817 msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
818}
819
820static irqreturn_t trf7970a_irq(int irq, void *dev_id)
821{
822 struct trf7970a *trf = dev_id;
823 int ret;
824 u8 status, fifo_bytes, iso_ctrl;
825
826 mutex_lock(&trf->lock);
827
828 if (trf->state == TRF7970A_ST_RF_OFF) {
829 mutex_unlock(&trf->lock);
830 return IRQ_NONE;
831 }
832
833 ret = trf7970a_read_irqstatus(trf, &status);
834 if (ret) {
835 mutex_unlock(&trf->lock);
836 return IRQ_NONE;
837 }
838
839 dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
840 status);
841
842 if (!status) {
843 mutex_unlock(&trf->lock);
844 return IRQ_NONE;
845 }
846
847 switch (trf->state) {
848 case TRF7970A_ST_IDLE:
849 case TRF7970A_ST_IDLE_RX_BLOCKED:
850 /* If initiator and getting interrupts caused by RF noise,
851 * turn off the receiver to avoid unnecessary interrupts.
852 * It will be turned back on in trf7970a_send_cmd() when
853 * the next command is issued.
854 */
855 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
856 trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
857 trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
858 }
859
860 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
861 break;
862 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
863 if (status & TRF7970A_IRQ_STATUS_TX) {
864 trf->ignore_timeout =
865 !cancel_delayed_work(&trf->timeout_work);
866 trf7970a_fill_fifo(trf);
867 } else {
868 trf7970a_send_err_upstream(trf, -EIO);
869 }
870 break;
871 case TRF7970A_ST_WAIT_FOR_RX_DATA:
872 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
873 if (status & TRF7970A_IRQ_STATUS_SRX) {
874 trf->ignore_timeout =
875 !cancel_delayed_work(&trf->timeout_work);
876 trf7970a_drain_fifo(trf, status);
877 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
878 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
879 &fifo_bytes);
880
881 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
882
883 if (ret)
884 trf7970a_send_err_upstream(trf, ret);
885 else if (!fifo_bytes)
886 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
887 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
888 (!trf->is_initiator &&
889 (status == (TRF7970A_IRQ_STATUS_TX |
890 TRF7970A_IRQ_STATUS_NFC_RF)))) {
891 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
892
893 if (!trf->timeout) {
894 trf->ignore_timeout =
895 !cancel_delayed_work(&trf->timeout_work);
896 trf->rx_skb = ERR_PTR(0);
897 trf7970a_send_upstream(trf);
898 break;
899 }
900
901 if (trf->is_initiator)
902 break;
903
904 iso_ctrl = trf->iso_ctrl;
905
906 switch (trf->framing) {
907 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
908 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
909 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
910 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
911 break;
912 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
913 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
914 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
915 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
916 break;
917 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
918 ret = trf7970a_write(trf,
919 TRF7970A_SPECIAL_FCN_REG1,
920 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
921 if (ret)
922 goto err_unlock_exit;
923
924 trf->special_fcn_reg1 =
925 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
926 break;
927 default:
928 break;
929 }
930
931 if (iso_ctrl != trf->iso_ctrl) {
932 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
933 iso_ctrl);
934 if (ret)
935 goto err_unlock_exit;
936
937 trf->iso_ctrl = iso_ctrl;
938 }
939 } else {
940 trf7970a_send_err_upstream(trf, -EIO);
941 }
942 break;
943 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
944 if (status != TRF7970A_IRQ_STATUS_TX)
945 trf7970a_send_err_upstream(trf, -EIO);
946 break;
947 case TRF7970A_ST_LISTENING:
948 if (status & TRF7970A_IRQ_STATUS_SRX) {
949 trf->ignore_timeout =
950 !cancel_delayed_work(&trf->timeout_work);
951 trf7970a_drain_fifo(trf, status);
952 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
953 trf7970a_send_err_upstream(trf, -EIO);
954 }
955 break;
956 case TRF7970A_ST_LISTENING_MD:
957 if (status & TRF7970A_IRQ_STATUS_SRX) {
958 trf->ignore_timeout =
959 !cancel_delayed_work(&trf->timeout_work);
960
961 ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
962 if (ret) {
963 trf7970a_send_err_upstream(trf, ret);
964 } else {
965 trf->state = TRF7970A_ST_LISTENING;
966 trf7970a_drain_fifo(trf, status);
967 }
968 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
969 trf7970a_send_err_upstream(trf, -EIO);
970 }
971 break;
972 default:
973 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
974 __func__, trf->state);
975 }
976
977err_unlock_exit:
978 mutex_unlock(&trf->lock);
979 return IRQ_HANDLED;
980}
981
982static void trf7970a_issue_eof(struct trf7970a *trf)
983{
984 int ret;
985
986 dev_dbg(trf->dev, "Issuing EOF\n");
987
988 ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
989 if (ret)
990 trf7970a_send_err_upstream(trf, ret);
991
992 ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
993 if (ret)
994 trf7970a_send_err_upstream(trf, ret);
995
996 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
997
998 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
999 trf->timeout, trf->state);
1000
1001 schedule_delayed_work(&trf->timeout_work,
1002 msecs_to_jiffies(trf->timeout));
1003}
1004
1005static void trf7970a_timeout_work_handler(struct work_struct *work)
1006{
1007 struct trf7970a *trf = container_of(work, struct trf7970a,
1008 timeout_work.work);
1009
1010 dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1011 trf->state, trf->ignore_timeout);
1012
1013 mutex_lock(&trf->lock);
1014
1015 if (trf->ignore_timeout)
1016 trf->ignore_timeout = false;
1017 else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1018 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1019 else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1020 trf7970a_issue_eof(trf);
1021 else
1022 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1023
1024 mutex_unlock(&trf->lock);
1025}
1026
1027static int trf7970a_init(struct trf7970a *trf)
1028{
1029 int ret;
1030
1031 dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1032
1033 ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1034 if (ret)
1035 goto err_out;
1036
1037 ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1038 if (ret)
1039 goto err_out;
1040
1041 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1042 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1043 if (ret)
1044 goto err_out;
1045
1046 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1047 if (ret)
1048 goto err_out;
1049
1050 usleep_range(1000, 2000);
1051
1052 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1053
1054 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1055 trf->modulator_sys_clk_ctrl);
1056 if (ret)
1057 goto err_out;
1058
1059 ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1060 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1061 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1062 if (ret)
1063 goto err_out;
1064
1065 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1066 if (ret)
1067 goto err_out;
1068
1069 trf->special_fcn_reg1 = 0;
1070
1071 trf->iso_ctrl = 0xff;
1072 return 0;
1073
1074err_out:
1075 dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1076 return ret;
1077}
1078
1079static void trf7970a_switch_rf_off(struct trf7970a *trf)
1080{
1081 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1082 (trf->state == TRF7970A_ST_RF_OFF))
1083 return;
1084
1085 dev_dbg(trf->dev, "Switching rf off\n");
1086
1087 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1088
1089 trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1090
1091 trf->aborting = false;
1092 trf->state = TRF7970A_ST_RF_OFF;
1093
1094 pm_runtime_mark_last_busy(trf->dev);
1095 pm_runtime_put_autosuspend(trf->dev);
1096}
1097
1098static int trf7970a_switch_rf_on(struct trf7970a *trf)
1099{
1100 int ret;
1101
1102 dev_dbg(trf->dev, "Switching rf on\n");
1103
1104 pm_runtime_get_sync(trf->dev);
1105
1106 if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1107 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1108 trf->state);
1109 return -EINVAL;
1110 }
1111
1112 ret = trf7970a_init(trf);
1113 if (ret) {
1114 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1115 return ret;
1116 }
1117
1118 trf->state = TRF7970A_ST_IDLE;
1119
1120 return 0;
1121}
1122
1123static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1124{
1125 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1126 int ret = 0;
1127
1128 dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1129
1130 mutex_lock(&trf->lock);
1131
1132 if (on) {
1133 switch (trf->state) {
1134 case TRF7970A_ST_PWR_OFF:
1135 case TRF7970A_ST_RF_OFF:
1136 ret = trf7970a_switch_rf_on(trf);
1137 break;
1138 case TRF7970A_ST_IDLE:
1139 case TRF7970A_ST_IDLE_RX_BLOCKED:
1140 break;
1141 default:
1142 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1143 __func__, trf->state, on);
1144 trf7970a_switch_rf_off(trf);
1145 ret = -EINVAL;
1146 }
1147 } else {
1148 switch (trf->state) {
1149 case TRF7970A_ST_PWR_OFF:
1150 case TRF7970A_ST_RF_OFF:
1151 break;
1152 default:
1153 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1154 __func__, trf->state, on);
1155 ret = -EINVAL;
1156 fallthrough;
1157 case TRF7970A_ST_IDLE:
1158 case TRF7970A_ST_IDLE_RX_BLOCKED:
1159 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1160 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1161 trf7970a_switch_rf_off(trf);
1162 }
1163 }
1164
1165 mutex_unlock(&trf->lock);
1166 return ret;
1167}
1168
1169static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1170{
1171 int ret = 0;
1172
1173 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1174
1175 switch (tech) {
1176 case NFC_DIGITAL_RF_TECH_106A:
1177 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1178 trf->modulator_sys_clk_ctrl =
1179 (trf->modulator_sys_clk_ctrl & 0xf8) |
1180 TRF7970A_MODULATOR_DEPTH_OOK;
1181 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1182 break;
1183 case NFC_DIGITAL_RF_TECH_106B:
1184 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1185 trf->modulator_sys_clk_ctrl =
1186 (trf->modulator_sys_clk_ctrl & 0xf8) |
1187 TRF7970A_MODULATOR_DEPTH_ASK10;
1188 trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1189 break;
1190 case NFC_DIGITAL_RF_TECH_212F:
1191 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1192 trf->modulator_sys_clk_ctrl =
1193 (trf->modulator_sys_clk_ctrl & 0xf8) |
1194 TRF7970A_MODULATOR_DEPTH_ASK10;
1195 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1196 break;
1197 case NFC_DIGITAL_RF_TECH_424F:
1198 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1199 trf->modulator_sys_clk_ctrl =
1200 (trf->modulator_sys_clk_ctrl & 0xf8) |
1201 TRF7970A_MODULATOR_DEPTH_ASK10;
1202 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1203 break;
1204 case NFC_DIGITAL_RF_TECH_ISO15693:
1205 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1206 trf->modulator_sys_clk_ctrl =
1207 (trf->modulator_sys_clk_ctrl & 0xf8) |
1208 TRF7970A_MODULATOR_DEPTH_OOK;
1209 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1210 break;
1211 default:
1212 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1213 return -EINVAL;
1214 }
1215
1216 trf->technology = tech;
1217
1218 /* If in initiator mode and not changing the RF tech due to a
1219 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1220 * trf7970a_init()), clear the NFC Target Detection Level register
1221 * due to erratum.
1222 */
1223 if (trf->iso_ctrl == 0xff)
1224 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1225
1226 return ret;
1227}
1228
1229static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1230{
1231 int ret;
1232 u8 rssi;
1233
1234 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1235 trf->chip_status_ctrl |
1236 TRF7970A_CHIP_STATUS_REC_ON);
1237 if (ret)
1238 return ret;
1239
1240 ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1241 if (ret)
1242 return ret;
1243
1244 usleep_range(50, 60);
1245
1246 ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1247 if (ret)
1248 return ret;
1249
1250 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1251 trf->chip_status_ctrl);
1252 if (ret)
1253 return ret;
1254
1255 if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1256 *is_rf_field = true;
1257 else
1258 *is_rf_field = false;
1259
1260 return 0;
1261}
1262
1263static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1264{
1265 u8 iso_ctrl = trf->iso_ctrl_tech;
1266 bool is_rf_field = false;
1267 int ret;
1268
1269 dev_dbg(trf->dev, "framing: %d\n", framing);
1270
1271 switch (framing) {
1272 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1273 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1274 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1275 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1276 break;
1277 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1278 case NFC_DIGITAL_FRAMING_NFCA_T4T:
1279 case NFC_DIGITAL_FRAMING_NFCB:
1280 case NFC_DIGITAL_FRAMING_NFCB_T4T:
1281 case NFC_DIGITAL_FRAMING_NFCF:
1282 case NFC_DIGITAL_FRAMING_NFCF_T3T:
1283 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1284 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1285 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1286 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1287 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1288 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1289 break;
1290 case NFC_DIGITAL_FRAMING_NFCA_T2T:
1291 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1292 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1293 break;
1294 default:
1295 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1296 return -EINVAL;
1297 }
1298
1299 trf->framing = framing;
1300
1301 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1302 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1303 if (ret)
1304 return ret;
1305
1306 if (is_rf_field)
1307 return -EBUSY;
1308 }
1309
1310 if (iso_ctrl != trf->iso_ctrl) {
1311 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1312 if (ret)
1313 return ret;
1314
1315 trf->iso_ctrl = iso_ctrl;
1316
1317 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1318 trf->modulator_sys_clk_ctrl);
1319 if (ret)
1320 return ret;
1321 }
1322
1323 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1324 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1325 trf->chip_status_ctrl |
1326 TRF7970A_CHIP_STATUS_RF_ON);
1327 if (ret)
1328 return ret;
1329
1330 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1331
1332 usleep_range(trf->guard_time, trf->guard_time + 1000);
1333 }
1334
1335 return 0;
1336}
1337
1338static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1339 int param)
1340{
1341 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1342 int ret;
1343
1344 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1345
1346 mutex_lock(&trf->lock);
1347
1348 trf->is_initiator = true;
1349
1350 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1351 (trf->state == TRF7970A_ST_RF_OFF)) {
1352 ret = trf7970a_switch_rf_on(trf);
1353 if (ret)
1354 goto err_unlock;
1355 }
1356
1357 switch (type) {
1358 case NFC_DIGITAL_CONFIG_RF_TECH:
1359 ret = trf7970a_in_config_rf_tech(trf, param);
1360 break;
1361 case NFC_DIGITAL_CONFIG_FRAMING:
1362 ret = trf7970a_in_config_framing(trf, param);
1363 break;
1364 default:
1365 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1366 ret = -EINVAL;
1367 }
1368
1369err_unlock:
1370 mutex_unlock(&trf->lock);
1371 return ret;
1372}
1373
1374static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1375{
1376 switch (cmd) {
1377 case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1378 case ISO15693_CMD_LOCK_BLOCK:
1379 case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1380 case ISO15693_CMD_WRITE_AFI:
1381 case ISO15693_CMD_LOCK_AFI:
1382 case ISO15693_CMD_WRITE_DSFID:
1383 case ISO15693_CMD_LOCK_DSFID:
1384 return 1;
1385 default:
1386 return 0;
1387 }
1388}
1389
1390static int trf7970a_per_cmd_config(struct trf7970a *trf,
1391 const struct sk_buff *skb)
1392{
1393 const u8 *req = skb->data;
1394 u8 special_fcn_reg1, iso_ctrl;
1395 int ret;
1396
1397 trf->issue_eof = false;
1398
1399 /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1400 * special functions register 1 is cleared; otherwise, its a write or
1401 * sector select command and '4_bit_RX' must be set.
1402 *
1403 * When issuing an ISO 15693 command, inspect the flags byte to see
1404 * what speed to use. Also, remember if the OPTION flag is set on
1405 * a Type 5 write or lock command so the driver will know that it
1406 * has to send an EOF in order to get a response.
1407 */
1408 if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1409 (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1410 if (req[0] == NFC_T2T_CMD_READ)
1411 special_fcn_reg1 = 0;
1412 else
1413 special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1414
1415 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1416 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1417 special_fcn_reg1);
1418 if (ret)
1419 return ret;
1420
1421 trf->special_fcn_reg1 = special_fcn_reg1;
1422 }
1423 } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1424 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1425
1426 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1427 case 0x00:
1428 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1429 break;
1430 case ISO15693_REQ_FLAG_SUB_CARRIER:
1431 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1432 break;
1433 case ISO15693_REQ_FLAG_DATA_RATE:
1434 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1435 break;
1436 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1437 ISO15693_REQ_FLAG_DATA_RATE):
1438 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1439 break;
1440 }
1441
1442 if (iso_ctrl != trf->iso_ctrl) {
1443 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1444 if (ret)
1445 return ret;
1446
1447 trf->iso_ctrl = iso_ctrl;
1448 }
1449
1450 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1451 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1452 (req[0] & ISO15693_REQ_FLAG_OPTION))
1453 trf->issue_eof = true;
1454 }
1455
1456 return 0;
1457}
1458
1459static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1460 struct sk_buff *skb, u16 timeout,
1461 nfc_digital_cmd_complete_t cb, void *arg)
1462{
1463 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1464 u8 prefix[5];
1465 unsigned int len;
1466 int ret;
1467 u8 status;
1468
1469 dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1470 trf->state, timeout, skb->len);
1471
1472 if (skb->len > TRF7970A_TX_MAX)
1473 return -EINVAL;
1474
1475 mutex_lock(&trf->lock);
1476
1477 if ((trf->state != TRF7970A_ST_IDLE) &&
1478 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1479 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1480 trf->state);
1481 ret = -EIO;
1482 goto out_err;
1483 }
1484
1485 if (trf->aborting) {
1486 dev_dbg(trf->dev, "Abort process complete\n");
1487 trf->aborting = false;
1488 ret = -ECANCELED;
1489 goto out_err;
1490 }
1491
1492 if (timeout) {
1493 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1494 GFP_KERNEL);
1495 if (!trf->rx_skb) {
1496 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1497 ret = -ENOMEM;
1498 goto out_err;
1499 }
1500 }
1501
1502 if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1503 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1504 if (ret)
1505 goto out_err;
1506
1507 trf->state = TRF7970A_ST_IDLE;
1508 }
1509
1510 if (trf->is_initiator) {
1511 ret = trf7970a_per_cmd_config(trf, skb);
1512 if (ret)
1513 goto out_err;
1514 }
1515
1516 trf->ddev = ddev;
1517 trf->tx_skb = skb;
1518 trf->cb = cb;
1519 trf->cb_arg = arg;
1520 trf->timeout = timeout;
1521 trf->ignore_timeout = false;
1522
1523 len = skb->len;
1524
1525 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1526 * on what the current framing is, the address of the TX length byte 1
1527 * register (0x1d), and the 2 byte length of the data to be transmitted.
1528 * That totals 5 bytes.
1529 */
1530 prefix[0] = TRF7970A_CMD_BIT_CTRL |
1531 TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1532 prefix[1] = TRF7970A_CMD_BIT_CTRL |
1533 TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1534 prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1535
1536 if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1537 prefix[3] = 0x00;
1538 prefix[4] = 0x0f; /* 7 bits */
1539 } else {
1540 prefix[3] = (len & 0xf00) >> 4;
1541 prefix[3] |= ((len & 0xf0) >> 4);
1542 prefix[4] = ((len & 0x0f) << 4);
1543 }
1544
1545 len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1546
1547 /* Clear possible spurious interrupt */
1548 ret = trf7970a_read_irqstatus(trf, &status);
1549 if (ret)
1550 goto out_err;
1551
1552 ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1553 if (ret) {
1554 kfree_skb(trf->rx_skb);
1555 trf->rx_skb = NULL;
1556 }
1557
1558out_err:
1559 mutex_unlock(&trf->lock);
1560 return ret;
1561}
1562
1563static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1564{
1565 int ret = 0;
1566
1567 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1568
1569 switch (tech) {
1570 case NFC_DIGITAL_RF_TECH_106A:
1571 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1572 TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1573 trf->modulator_sys_clk_ctrl =
1574 (trf->modulator_sys_clk_ctrl & 0xf8) |
1575 TRF7970A_MODULATOR_DEPTH_OOK;
1576 break;
1577 case NFC_DIGITAL_RF_TECH_212F:
1578 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1579 TRF7970A_ISO_CTRL_NFC_NFCF_212;
1580 trf->modulator_sys_clk_ctrl =
1581 (trf->modulator_sys_clk_ctrl & 0xf8) |
1582 TRF7970A_MODULATOR_DEPTH_ASK10;
1583 break;
1584 case NFC_DIGITAL_RF_TECH_424F:
1585 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1586 TRF7970A_ISO_CTRL_NFC_NFCF_424;
1587 trf->modulator_sys_clk_ctrl =
1588 (trf->modulator_sys_clk_ctrl & 0xf8) |
1589 TRF7970A_MODULATOR_DEPTH_ASK10;
1590 break;
1591 default:
1592 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1593 return -EINVAL;
1594 }
1595
1596 trf->technology = tech;
1597
1598 /* Normally we write the ISO_CTRL register in
1599 * trf7970a_tg_config_framing() because the framing can change
1600 * the value written. However, when sending a PSL RES,
1601 * digital_tg_send_psl_res_complete() doesn't call
1602 * trf7970a_tg_config_framing() so we must write the register
1603 * here.
1604 */
1605 if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1606 (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1607 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1608 trf->iso_ctrl_tech);
1609
1610 trf->iso_ctrl = trf->iso_ctrl_tech;
1611 }
1612
1613 return ret;
1614}
1615
1616/* Since this is a target routine, several of the framing calls are
1617 * made between receiving the request and sending the response so they
1618 * should take effect until after the response is sent. This is accomplished
1619 * by skipping the ISO_CTRL register write here and doing it in the interrupt
1620 * handler.
1621 */
1622static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1623{
1624 u8 iso_ctrl = trf->iso_ctrl_tech;
1625 int ret;
1626
1627 dev_dbg(trf->dev, "framing: %d\n", framing);
1628
1629 switch (framing) {
1630 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1631 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1632 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1633 break;
1634 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1635 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1636 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1637 /* These ones are applied in the interrupt handler */
1638 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1639 break;
1640 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1641 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1642 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1643 break;
1644 case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1645 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1646 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1647 break;
1648 default:
1649 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1650 return -EINVAL;
1651 }
1652
1653 trf->framing = framing;
1654
1655 if (iso_ctrl != trf->iso_ctrl) {
1656 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1657 if (ret)
1658 return ret;
1659
1660 trf->iso_ctrl = iso_ctrl;
1661
1662 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1663 trf->modulator_sys_clk_ctrl);
1664 if (ret)
1665 return ret;
1666 }
1667
1668 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1669 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1670 trf->chip_status_ctrl |
1671 TRF7970A_CHIP_STATUS_RF_ON);
1672 if (ret)
1673 return ret;
1674
1675 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1676 }
1677
1678 return 0;
1679}
1680
1681static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1682 int param)
1683{
1684 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1685 int ret;
1686
1687 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1688
1689 mutex_lock(&trf->lock);
1690
1691 trf->is_initiator = false;
1692
1693 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1694 (trf->state == TRF7970A_ST_RF_OFF)) {
1695 ret = trf7970a_switch_rf_on(trf);
1696 if (ret)
1697 goto err_unlock;
1698 }
1699
1700 switch (type) {
1701 case NFC_DIGITAL_CONFIG_RF_TECH:
1702 ret = trf7970a_tg_config_rf_tech(trf, param);
1703 break;
1704 case NFC_DIGITAL_CONFIG_FRAMING:
1705 ret = trf7970a_tg_config_framing(trf, param);
1706 break;
1707 default:
1708 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1709 ret = -EINVAL;
1710 }
1711
1712err_unlock:
1713 mutex_unlock(&trf->lock);
1714 return ret;
1715}
1716
1717static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1718 nfc_digital_cmd_complete_t cb, void *arg,
1719 bool mode_detect)
1720{
1721 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1722 int ret;
1723
1724 mutex_lock(&trf->lock);
1725
1726 if ((trf->state != TRF7970A_ST_IDLE) &&
1727 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1728 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1729 trf->state);
1730 ret = -EIO;
1731 goto out_err;
1732 }
1733
1734 if (trf->aborting) {
1735 dev_dbg(trf->dev, "Abort process complete\n");
1736 trf->aborting = false;
1737 ret = -ECANCELED;
1738 goto out_err;
1739 }
1740
1741 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1742 GFP_KERNEL);
1743 if (!trf->rx_skb) {
1744 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1745 ret = -ENOMEM;
1746 goto out_err;
1747 }
1748
1749 ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1750 TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1751 TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1752 TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1753 TRF7970A_RX_SPECIAL_SETTINGS_C212);
1754 if (ret)
1755 goto out_err;
1756
1757 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1758 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1759 if (ret)
1760 goto out_err;
1761
1762 ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1763 TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1764 if (ret)
1765 goto out_err;
1766
1767 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1768 TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1769 if (ret)
1770 goto out_err;
1771
1772 trf->ddev = ddev;
1773 trf->cb = cb;
1774 trf->cb_arg = arg;
1775 trf->timeout = timeout;
1776 trf->ignore_timeout = false;
1777
1778 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1779 if (ret)
1780 goto out_err;
1781
1782 trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1783 TRF7970A_ST_LISTENING;
1784
1785 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1786
1787out_err:
1788 mutex_unlock(&trf->lock);
1789 return ret;
1790}
1791
1792static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1793 nfc_digital_cmd_complete_t cb, void *arg)
1794{
1795 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1796
1797 dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1798 trf->state, timeout);
1799
1800 return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1801}
1802
1803static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1804 u16 timeout, nfc_digital_cmd_complete_t cb,
1805 void *arg)
1806{
1807 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1808 int ret;
1809
1810 dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1811 trf->state, timeout);
1812
1813 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1814 NFC_DIGITAL_RF_TECH_106A);
1815 if (ret)
1816 return ret;
1817
1818 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1819 NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1820 if (ret)
1821 return ret;
1822
1823 return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1824}
1825
1826static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1827{
1828 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1829
1830 dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1831 trf->state, trf->md_rf_tech);
1832
1833 *rf_tech = trf->md_rf_tech;
1834
1835 return 0;
1836}
1837
1838static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1839{
1840 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1841
1842 dev_dbg(trf->dev, "Abort process initiated\n");
1843
1844 mutex_lock(&trf->lock);
1845
1846 switch (trf->state) {
1847 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1848 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1849 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1850 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1851 trf->aborting = true;
1852 break;
1853 case TRF7970A_ST_LISTENING:
1854 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1855 trf7970a_send_err_upstream(trf, -ECANCELED);
1856 dev_dbg(trf->dev, "Abort process complete\n");
1857 break;
1858 default:
1859 break;
1860 }
1861
1862 mutex_unlock(&trf->lock);
1863}
1864
1865static const struct nfc_digital_ops trf7970a_nfc_ops = {
1866 .in_configure_hw = trf7970a_in_configure_hw,
1867 .in_send_cmd = trf7970a_send_cmd,
1868 .tg_configure_hw = trf7970a_tg_configure_hw,
1869 .tg_send_cmd = trf7970a_send_cmd,
1870 .tg_listen = trf7970a_tg_listen,
1871 .tg_listen_md = trf7970a_tg_listen_md,
1872 .tg_get_rf_tech = trf7970a_tg_get_rf_tech,
1873 .switch_rf = trf7970a_switch_rf,
1874 .abort_cmd = trf7970a_abort_cmd,
1875};
1876
1877static int trf7970a_power_up(struct trf7970a *trf)
1878{
1879 int ret;
1880
1881 dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1882
1883 if (trf->state != TRF7970A_ST_PWR_OFF)
1884 return 0;
1885
1886 ret = regulator_enable(trf->regulator);
1887 if (ret) {
1888 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1889 return ret;
1890 }
1891
1892 usleep_range(5000, 6000);
1893
1894 if (trf->en2_gpiod &&
1895 !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1896 gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1897 usleep_range(1000, 2000);
1898 }
1899
1900 gpiod_set_value_cansleep(trf->en_gpiod, 1);
1901
1902 usleep_range(20000, 21000);
1903
1904 trf->state = TRF7970A_ST_RF_OFF;
1905
1906 return 0;
1907}
1908
1909static int trf7970a_power_down(struct trf7970a *trf)
1910{
1911 int ret;
1912
1913 dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1914
1915 if (trf->state == TRF7970A_ST_PWR_OFF)
1916 return 0;
1917
1918 if (trf->state != TRF7970A_ST_RF_OFF) {
1919 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1920 trf->state);
1921 return -EBUSY;
1922 }
1923
1924 gpiod_set_value_cansleep(trf->en_gpiod, 0);
1925
1926 if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1927 gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1928
1929 ret = regulator_disable(trf->regulator);
1930 if (ret)
1931 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1932 ret);
1933
1934 trf->state = TRF7970A_ST_PWR_OFF;
1935
1936 return ret;
1937}
1938
1939static int trf7970a_startup(struct trf7970a *trf)
1940{
1941 int ret;
1942
1943 ret = trf7970a_power_up(trf);
1944 if (ret)
1945 return ret;
1946
1947 pm_runtime_set_active(trf->dev);
1948 pm_runtime_enable(trf->dev);
1949 pm_runtime_mark_last_busy(trf->dev);
1950
1951 return 0;
1952}
1953
1954static void trf7970a_shutdown(struct trf7970a *trf)
1955{
1956 switch (trf->state) {
1957 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1958 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1959 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1960 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1961 case TRF7970A_ST_LISTENING:
1962 trf7970a_send_err_upstream(trf, -ECANCELED);
1963 fallthrough;
1964 case TRF7970A_ST_IDLE:
1965 case TRF7970A_ST_IDLE_RX_BLOCKED:
1966 trf7970a_switch_rf_off(trf);
1967 break;
1968 default:
1969 break;
1970 }
1971
1972 pm_runtime_disable(trf->dev);
1973 pm_runtime_set_suspended(trf->dev);
1974
1975 trf7970a_power_down(trf);
1976}
1977
1978static int trf7970a_get_autosuspend_delay(const struct device_node *np)
1979{
1980 int autosuspend_delay, ret;
1981
1982 ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1983 if (ret)
1984 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1985
1986 return autosuspend_delay;
1987}
1988
1989static int trf7970a_probe(struct spi_device *spi)
1990{
1991 const struct device_node *np = spi->dev.of_node;
1992 struct trf7970a *trf;
1993 int uvolts, autosuspend_delay, ret;
1994 u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1995
1996 if (!np) {
1997 dev_err(&spi->dev, "No Device Tree entry\n");
1998 return -EINVAL;
1999 }
2000
2001 trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2002 if (!trf)
2003 return -ENOMEM;
2004
2005 trf->state = TRF7970A_ST_PWR_OFF;
2006 trf->dev = &spi->dev;
2007 trf->spi = spi;
2008
2009 spi->mode = SPI_MODE_1;
2010 spi->bits_per_word = 8;
2011
2012 ret = spi_setup(spi);
2013 if (ret < 0) {
2014 dev_err(trf->dev, "Can't set up SPI Communication\n");
2015 return ret;
2016 }
2017
2018 if (of_property_read_bool(np, "irq-status-read-quirk"))
2019 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2020
2021 /* There are two enable pins - only EN must be present in the DT */
2022 trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2023 GPIOD_OUT_LOW);
2024 if (IS_ERR(trf->en_gpiod)) {
2025 dev_err(trf->dev, "No EN GPIO property\n");
2026 return PTR_ERR(trf->en_gpiod);
2027 }
2028
2029 trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2030 GPIOD_OUT_LOW);
2031 if (!trf->en2_gpiod) {
2032 dev_info(trf->dev, "No EN2 GPIO property\n");
2033 } else if (IS_ERR(trf->en2_gpiod)) {
2034 dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2035 PTR_ERR(trf->en2_gpiod));
2036 return PTR_ERR(trf->en2_gpiod);
2037 } else if (of_property_read_bool(np, "en2-rf-quirk")) {
2038 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2039 }
2040
2041 of_property_read_u32(np, "clock-frequency", &clk_freq);
2042 if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2043 (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2044 dev_err(trf->dev,
2045 "clock-frequency (%u Hz) unsupported\n", clk_freq);
2046 return -EINVAL;
2047 }
2048
2049 if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2050 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2051 dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2052 } else {
2053 trf->modulator_sys_clk_ctrl = 0;
2054 }
2055
2056 ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2057 trf7970a_irq,
2058 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2059 "trf7970a", trf);
2060 if (ret) {
2061 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2062 return ret;
2063 }
2064
2065 mutex_init(&trf->lock);
2066 INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2067
2068 trf->regulator = devm_regulator_get(&spi->dev, "vin");
2069 if (IS_ERR(trf->regulator)) {
2070 ret = PTR_ERR(trf->regulator);
2071 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2072 goto err_destroy_lock;
2073 }
2074
2075 ret = regulator_enable(trf->regulator);
2076 if (ret) {
2077 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2078 goto err_destroy_lock;
2079 }
2080
2081 uvolts = regulator_get_voltage(trf->regulator);
2082 if (uvolts > 4000000)
2083 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2084
2085 trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2086 if (IS_ERR(trf->regulator)) {
2087 ret = PTR_ERR(trf->regulator);
2088 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2089 goto err_destroy_lock;
2090 }
2091
2092 ret = regulator_enable(trf->regulator);
2093 if (ret) {
2094 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2095 goto err_destroy_lock;
2096 }
2097
2098 if (regulator_get_voltage(trf->regulator) == 1800000) {
2099 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2100 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2101 }
2102
2103 trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2104 TRF7970A_SUPPORTED_PROTOCOLS,
2105 NFC_DIGITAL_DRV_CAPS_IN_CRC |
2106 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2107 0);
2108 if (!trf->ddev) {
2109 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2110 ret = -ENOMEM;
2111 goto err_disable_regulator;
2112 }
2113
2114 nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2115 nfc_digital_set_drvdata(trf->ddev, trf);
2116 spi_set_drvdata(spi, trf);
2117
2118 autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2119
2120 pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2121 pm_runtime_use_autosuspend(trf->dev);
2122
2123 ret = trf7970a_startup(trf);
2124 if (ret)
2125 goto err_free_ddev;
2126
2127 ret = nfc_digital_register_device(trf->ddev);
2128 if (ret) {
2129 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2130 ret);
2131 goto err_shutdown;
2132 }
2133
2134 return 0;
2135
2136err_shutdown:
2137 trf7970a_shutdown(trf);
2138err_free_ddev:
2139 nfc_digital_free_device(trf->ddev);
2140err_disable_regulator:
2141 regulator_disable(trf->regulator);
2142err_destroy_lock:
2143 mutex_destroy(&trf->lock);
2144 return ret;
2145}
2146
2147static void trf7970a_remove(struct spi_device *spi)
2148{
2149 struct trf7970a *trf = spi_get_drvdata(spi);
2150
2151 mutex_lock(&trf->lock);
2152
2153 trf7970a_shutdown(trf);
2154
2155 mutex_unlock(&trf->lock);
2156
2157 nfc_digital_unregister_device(trf->ddev);
2158 nfc_digital_free_device(trf->ddev);
2159
2160 regulator_disable(trf->regulator);
2161
2162 mutex_destroy(&trf->lock);
2163}
2164
2165#ifdef CONFIG_PM_SLEEP
2166static int trf7970a_suspend(struct device *dev)
2167{
2168 struct spi_device *spi = to_spi_device(dev);
2169 struct trf7970a *trf = spi_get_drvdata(spi);
2170
2171 mutex_lock(&trf->lock);
2172
2173 trf7970a_shutdown(trf);
2174
2175 mutex_unlock(&trf->lock);
2176
2177 return 0;
2178}
2179
2180static int trf7970a_resume(struct device *dev)
2181{
2182 struct spi_device *spi = to_spi_device(dev);
2183 struct trf7970a *trf = spi_get_drvdata(spi);
2184 int ret;
2185
2186 mutex_lock(&trf->lock);
2187
2188 ret = trf7970a_startup(trf);
2189
2190 mutex_unlock(&trf->lock);
2191
2192 return ret;
2193}
2194#endif
2195
2196#ifdef CONFIG_PM
2197static int trf7970a_pm_runtime_suspend(struct device *dev)
2198{
2199 struct spi_device *spi = to_spi_device(dev);
2200 struct trf7970a *trf = spi_get_drvdata(spi);
2201 int ret;
2202
2203 mutex_lock(&trf->lock);
2204
2205 ret = trf7970a_power_down(trf);
2206
2207 mutex_unlock(&trf->lock);
2208
2209 return ret;
2210}
2211
2212static int trf7970a_pm_runtime_resume(struct device *dev)
2213{
2214 struct spi_device *spi = to_spi_device(dev);
2215 struct trf7970a *trf = spi_get_drvdata(spi);
2216 int ret;
2217
2218 ret = trf7970a_power_up(trf);
2219 if (!ret)
2220 pm_runtime_mark_last_busy(dev);
2221
2222 return ret;
2223}
2224#endif
2225
2226static const struct dev_pm_ops trf7970a_pm_ops = {
2227 SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2228 SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2229 trf7970a_pm_runtime_resume, NULL)
2230};
2231
2232static const struct of_device_id trf7970a_of_match[] = {
2233 {.compatible = "ti,trf7970a",},
2234 {},
2235};
2236
2237MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2238
2239static const struct spi_device_id trf7970a_id_table[] = {
2240 {"trf7970a", 0},
2241 {}
2242};
2243
2244MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2245
2246static struct spi_driver trf7970a_spi_driver = {
2247 .probe = trf7970a_probe,
2248 .remove = trf7970a_remove,
2249 .id_table = trf7970a_id_table,
2250 .driver = {
2251 .name = "trf7970a",
2252 .of_match_table = of_match_ptr(trf7970a_of_match),
2253 .pm = &trf7970a_pm_ops,
2254 },
2255};
2256
2257module_spi_driver(trf7970a_spi_driver);
2258
2259MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2260MODULE_LICENSE("GPL v2");
2261MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");