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1// SPDX-License-Identifier: GPL-2.0-only
2/* drivers/net/ethernet/micrel/ks8851.c
3 *
4 * Copyright 2009 Simtec Electronics
5 * http://www.simtec.co.uk/
6 * Ben Dooks <ben@simtec.co.uk>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#define DEBUG
12
13#include <linux/interrupt.h>
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/netdevice.h>
17#include <linux/etherdevice.h>
18#include <linux/ethtool.h>
19#include <linux/cache.h>
20#include <linux/crc32.h>
21#include <linux/mii.h>
22#include <linux/regulator/consumer.h>
23
24#include <linux/spi/spi.h>
25#include <linux/gpio.h>
26#include <linux/of_gpio.h>
27#include <linux/of_net.h>
28
29#include "ks8851.h"
30
31static int msg_enable;
32
33/**
34 * struct ks8851_net_spi - KS8851 SPI driver private data
35 * @lock: Lock to ensure that the device is not accessed when busy.
36 * @tx_work: Work queue for tx packets
37 * @ks8851: KS8851 driver common private data
38 * @spidev: The spi device we're bound to.
39 * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
40 * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2.
41 * @spi_xfer1: @spi_msg1 SPI transfer structure
42 * @spi_xfer2: @spi_msg2 SPI transfer structure
43 *
44 * The @lock ensures that the chip is protected when certain operations are
45 * in progress. When the read or write packet transfer is in progress, most
46 * of the chip registers are not ccessible until the transfer is finished and
47 * the DMA has been de-asserted.
48 */
49struct ks8851_net_spi {
50 struct ks8851_net ks8851;
51 struct mutex lock;
52 struct work_struct tx_work;
53 struct spi_device *spidev;
54 struct spi_message spi_msg1;
55 struct spi_message spi_msg2;
56 struct spi_transfer spi_xfer1;
57 struct spi_transfer spi_xfer2[2];
58};
59
60#define to_ks8851_spi(ks) container_of((ks), struct ks8851_net_spi, ks8851)
61
62/* SPI frame opcodes */
63#define KS_SPIOP_RD 0x00
64#define KS_SPIOP_WR 0x40
65#define KS_SPIOP_RXFIFO 0x80
66#define KS_SPIOP_TXFIFO 0xC0
67
68/* shift for byte-enable data */
69#define BYTE_EN(_x) ((_x) << 2)
70
71/* turn register number and byte-enable mask into data for start of packet */
72#define MK_OP(_byteen, _reg) \
73 (BYTE_EN(_byteen) | (_reg) << (8 + 2) | (_reg) >> 6)
74
75/**
76 * ks8851_lock_spi - register access lock
77 * @ks: The chip state
78 * @flags: Spinlock flags
79 *
80 * Claim chip register access lock
81 */
82static void ks8851_lock_spi(struct ks8851_net *ks, unsigned long *flags)
83{
84 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
85
86 mutex_lock(&kss->lock);
87}
88
89/**
90 * ks8851_unlock_spi - register access unlock
91 * @ks: The chip state
92 * @flags: Spinlock flags
93 *
94 * Release chip register access lock
95 */
96static void ks8851_unlock_spi(struct ks8851_net *ks, unsigned long *flags)
97{
98 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
99
100 mutex_unlock(&kss->lock);
101}
102
103/* SPI register read/write calls.
104 *
105 * All these calls issue SPI transactions to access the chip's registers. They
106 * all require that the necessary lock is held to prevent accesses when the
107 * chip is busy transferring packet data (RX/TX FIFO accesses).
108 */
109
110/**
111 * ks8851_wrreg16_spi - write 16bit register value to chip via SPI
112 * @ks: The chip state
113 * @reg: The register address
114 * @val: The value to write
115 *
116 * Issue a write to put the value @val into the register specified in @reg.
117 */
118static void ks8851_wrreg16_spi(struct ks8851_net *ks, unsigned int reg,
119 unsigned int val)
120{
121 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
122 struct spi_transfer *xfer = &kss->spi_xfer1;
123 struct spi_message *msg = &kss->spi_msg1;
124 __le16 txb[2];
125 int ret;
126
127 txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR);
128 txb[1] = cpu_to_le16(val);
129
130 xfer->tx_buf = txb;
131 xfer->rx_buf = NULL;
132 xfer->len = 4;
133
134 ret = spi_sync(kss->spidev, msg);
135 if (ret < 0)
136 netdev_err(ks->netdev, "spi_sync() failed\n");
137}
138
139/**
140 * ks8851_rdreg - issue read register command and return the data
141 * @ks: The device state
142 * @op: The register address and byte enables in message format.
143 * @rxb: The RX buffer to return the result into
144 * @rxl: The length of data expected.
145 *
146 * This is the low level read call that issues the necessary spi message(s)
147 * to read data from the register specified in @op.
148 */
149static void ks8851_rdreg(struct ks8851_net *ks, unsigned int op,
150 u8 *rxb, unsigned int rxl)
151{
152 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
153 struct spi_transfer *xfer;
154 struct spi_message *msg;
155 __le16 *txb = (__le16 *)ks->txd;
156 u8 *trx = ks->rxd;
157 int ret;
158
159 txb[0] = cpu_to_le16(op | KS_SPIOP_RD);
160
161 if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX) {
162 msg = &kss->spi_msg2;
163 xfer = kss->spi_xfer2;
164
165 xfer->tx_buf = txb;
166 xfer->rx_buf = NULL;
167 xfer->len = 2;
168
169 xfer++;
170 xfer->tx_buf = NULL;
171 xfer->rx_buf = trx;
172 xfer->len = rxl;
173 } else {
174 msg = &kss->spi_msg1;
175 xfer = &kss->spi_xfer1;
176
177 xfer->tx_buf = txb;
178 xfer->rx_buf = trx;
179 xfer->len = rxl + 2;
180 }
181
182 ret = spi_sync(kss->spidev, msg);
183 if (ret < 0)
184 netdev_err(ks->netdev, "read: spi_sync() failed\n");
185 else if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX)
186 memcpy(rxb, trx, rxl);
187 else
188 memcpy(rxb, trx + 2, rxl);
189}
190
191/**
192 * ks8851_rdreg16_spi - read 16 bit register from device via SPI
193 * @ks: The chip information
194 * @reg: The register address
195 *
196 * Read a 16bit register from the chip, returning the result
197 */
198static unsigned int ks8851_rdreg16_spi(struct ks8851_net *ks, unsigned int reg)
199{
200 __le16 rx = 0;
201
202 ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2);
203 return le16_to_cpu(rx);
204}
205
206/**
207 * ks8851_rdfifo_spi - read data from the receive fifo via SPI
208 * @ks: The device state.
209 * @buff: The buffer address
210 * @len: The length of the data to read
211 *
212 * Issue an RXQ FIFO read command and read the @len amount of data from
213 * the FIFO into the buffer specified by @buff.
214 */
215static void ks8851_rdfifo_spi(struct ks8851_net *ks, u8 *buff, unsigned int len)
216{
217 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
218 struct spi_transfer *xfer = kss->spi_xfer2;
219 struct spi_message *msg = &kss->spi_msg2;
220 u8 txb[1];
221 int ret;
222
223 netif_dbg(ks, rx_status, ks->netdev,
224 "%s: %d@%p\n", __func__, len, buff);
225
226 /* set the operation we're issuing */
227 txb[0] = KS_SPIOP_RXFIFO;
228
229 xfer->tx_buf = txb;
230 xfer->rx_buf = NULL;
231 xfer->len = 1;
232
233 xfer++;
234 xfer->rx_buf = buff;
235 xfer->tx_buf = NULL;
236 xfer->len = len;
237
238 ret = spi_sync(kss->spidev, msg);
239 if (ret < 0)
240 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
241}
242
243/**
244 * ks8851_wrfifo_spi - write packet to TX FIFO via SPI
245 * @ks: The device state.
246 * @txp: The sk_buff to transmit.
247 * @irq: IRQ on completion of the packet.
248 *
249 * Send the @txp to the chip. This means creating the relevant packet header
250 * specifying the length of the packet and the other information the chip
251 * needs, such as IRQ on completion. Send the header and the packet data to
252 * the device.
253 */
254static void ks8851_wrfifo_spi(struct ks8851_net *ks, struct sk_buff *txp,
255 bool irq)
256{
257 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
258 struct spi_transfer *xfer = kss->spi_xfer2;
259 struct spi_message *msg = &kss->spi_msg2;
260 unsigned int fid = 0;
261 int ret;
262
263 netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",
264 __func__, txp, txp->len, txp->data, irq);
265
266 fid = ks->fid++;
267 fid &= TXFR_TXFID_MASK;
268
269 if (irq)
270 fid |= TXFR_TXIC; /* irq on completion */
271
272 /* start header at txb[1] to align txw entries */
273 ks->txh.txb[1] = KS_SPIOP_TXFIFO;
274 ks->txh.txw[1] = cpu_to_le16(fid);
275 ks->txh.txw[2] = cpu_to_le16(txp->len);
276
277 xfer->tx_buf = &ks->txh.txb[1];
278 xfer->rx_buf = NULL;
279 xfer->len = 5;
280
281 xfer++;
282 xfer->tx_buf = txp->data;
283 xfer->rx_buf = NULL;
284 xfer->len = ALIGN(txp->len, 4);
285
286 ret = spi_sync(kss->spidev, msg);
287 if (ret < 0)
288 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
289}
290
291/**
292 * ks8851_rx_skb_spi - receive skbuff
293 * @ks: The device state
294 * @skb: The skbuff
295 */
296static void ks8851_rx_skb_spi(struct ks8851_net *ks, struct sk_buff *skb)
297{
298 netif_rx_ni(skb);
299}
300
301/**
302 * ks8851_tx_work - process tx packet(s)
303 * @work: The work strucutre what was scheduled.
304 *
305 * This is called when a number of packets have been scheduled for
306 * transmission and need to be sent to the device.
307 */
308static void ks8851_tx_work(struct work_struct *work)
309{
310 struct ks8851_net_spi *kss;
311 struct ks8851_net *ks;
312 unsigned long flags;
313 struct sk_buff *txb;
314 bool last;
315
316 kss = container_of(work, struct ks8851_net_spi, tx_work);
317 ks = &kss->ks8851;
318 last = skb_queue_empty(&ks->txq);
319
320 ks8851_lock_spi(ks, &flags);
321
322 while (!last) {
323 txb = skb_dequeue(&ks->txq);
324 last = skb_queue_empty(&ks->txq);
325
326 if (txb) {
327 ks8851_wrreg16_spi(ks, KS_RXQCR,
328 ks->rc_rxqcr | RXQCR_SDA);
329 ks8851_wrfifo_spi(ks, txb, last);
330 ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr);
331 ks8851_wrreg16_spi(ks, KS_TXQCR, TXQCR_METFE);
332
333 ks8851_done_tx(ks, txb);
334 }
335 }
336
337 ks8851_unlock_spi(ks, &flags);
338}
339
340/**
341 * ks8851_flush_tx_work_spi - flush outstanding TX work
342 * @ks: The device state
343 */
344static void ks8851_flush_tx_work_spi(struct ks8851_net *ks)
345{
346 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
347
348 flush_work(&kss->tx_work);
349}
350
351/**
352 * calc_txlen - calculate size of message to send packet
353 * @len: Length of data
354 *
355 * Returns the size of the TXFIFO message needed to send
356 * this packet.
357 */
358static unsigned int calc_txlen(unsigned int len)
359{
360 return ALIGN(len + 4, 4);
361}
362
363/**
364 * ks8851_start_xmit_spi - transmit packet using SPI
365 * @skb: The buffer to transmit
366 * @dev: The device used to transmit the packet.
367 *
368 * Called by the network layer to transmit the @skb. Queue the packet for
369 * the device and schedule the necessary work to transmit the packet when
370 * it is free.
371 *
372 * We do this to firstly avoid sleeping with the network device locked,
373 * and secondly so we can round up more than one packet to transmit which
374 * means we can try and avoid generating too many transmit done interrupts.
375 */
376static netdev_tx_t ks8851_start_xmit_spi(struct sk_buff *skb,
377 struct net_device *dev)
378{
379 unsigned int needed = calc_txlen(skb->len);
380 struct ks8851_net *ks = netdev_priv(dev);
381 netdev_tx_t ret = NETDEV_TX_OK;
382 struct ks8851_net_spi *kss;
383
384 kss = to_ks8851_spi(ks);
385
386 netif_dbg(ks, tx_queued, ks->netdev,
387 "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
388
389 spin_lock(&ks->statelock);
390
391 if (needed > ks->tx_space) {
392 netif_stop_queue(dev);
393 ret = NETDEV_TX_BUSY;
394 } else {
395 ks->tx_space -= needed;
396 skb_queue_tail(&ks->txq, skb);
397 }
398
399 spin_unlock(&ks->statelock);
400 schedule_work(&kss->tx_work);
401
402 return ret;
403}
404
405static int ks8851_probe_spi(struct spi_device *spi)
406{
407 struct device *dev = &spi->dev;
408 struct ks8851_net_spi *kss;
409 struct net_device *netdev;
410 struct ks8851_net *ks;
411
412 netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_spi));
413 if (!netdev)
414 return -ENOMEM;
415
416 spi->bits_per_word = 8;
417
418 ks = netdev_priv(netdev);
419
420 ks->lock = ks8851_lock_spi;
421 ks->unlock = ks8851_unlock_spi;
422 ks->rdreg16 = ks8851_rdreg16_spi;
423 ks->wrreg16 = ks8851_wrreg16_spi;
424 ks->rdfifo = ks8851_rdfifo_spi;
425 ks->wrfifo = ks8851_wrfifo_spi;
426 ks->start_xmit = ks8851_start_xmit_spi;
427 ks->rx_skb = ks8851_rx_skb_spi;
428 ks->flush_tx_work = ks8851_flush_tx_work_spi;
429
430#define STD_IRQ (IRQ_LCI | /* Link Change */ \
431 IRQ_TXI | /* TX done */ \
432 IRQ_RXI | /* RX done */ \
433 IRQ_SPIBEI | /* SPI bus error */ \
434 IRQ_TXPSI | /* TX process stop */ \
435 IRQ_RXPSI) /* RX process stop */
436 ks->rc_ier = STD_IRQ;
437
438 kss = to_ks8851_spi(ks);
439
440 kss->spidev = spi;
441 mutex_init(&kss->lock);
442 INIT_WORK(&kss->tx_work, ks8851_tx_work);
443
444 /* initialise pre-made spi transfer messages */
445 spi_message_init(&kss->spi_msg1);
446 spi_message_add_tail(&kss->spi_xfer1, &kss->spi_msg1);
447
448 spi_message_init(&kss->spi_msg2);
449 spi_message_add_tail(&kss->spi_xfer2[0], &kss->spi_msg2);
450 spi_message_add_tail(&kss->spi_xfer2[1], &kss->spi_msg2);
451
452 netdev->irq = spi->irq;
453
454 return ks8851_probe_common(netdev, dev, msg_enable);
455}
456
457static int ks8851_remove_spi(struct spi_device *spi)
458{
459 return ks8851_remove_common(&spi->dev);
460}
461
462static const struct of_device_id ks8851_match_table[] = {
463 { .compatible = "micrel,ks8851" },
464 { }
465};
466MODULE_DEVICE_TABLE(of, ks8851_match_table);
467
468static struct spi_driver ks8851_driver = {
469 .driver = {
470 .name = "ks8851",
471 .of_match_table = ks8851_match_table,
472 .pm = &ks8851_pm_ops,
473 },
474 .probe = ks8851_probe_spi,
475 .remove = ks8851_remove_spi,
476};
477module_spi_driver(ks8851_driver);
478
479MODULE_DESCRIPTION("KS8851 Network driver");
480MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
481MODULE_LICENSE("GPL");
482
483module_param_named(message, msg_enable, int, 0);
484MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");
485MODULE_ALIAS("spi:ks8851");
1// SPDX-License-Identifier: GPL-2.0-only
2/* drivers/net/ethernet/micrel/ks8851.c
3 *
4 * Copyright 2009 Simtec Electronics
5 * http://www.simtec.co.uk/
6 * Ben Dooks <ben@simtec.co.uk>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/interrupt.h>
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/netdevice.h>
15#include <linux/etherdevice.h>
16#include <linux/ethtool.h>
17#include <linux/cache.h>
18#include <linux/crc32.h>
19#include <linux/mii.h>
20#include <linux/regulator/consumer.h>
21
22#include <linux/spi/spi.h>
23#include <linux/gpio.h>
24#include <linux/of_gpio.h>
25#include <linux/of_net.h>
26
27#include "ks8851.h"
28
29static int msg_enable;
30
31/**
32 * struct ks8851_net_spi - KS8851 SPI driver private data
33 * @lock: Lock to ensure that the device is not accessed when busy.
34 * @tx_work: Work queue for tx packets
35 * @ks8851: KS8851 driver common private data
36 * @spidev: The spi device we're bound to.
37 * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
38 * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2.
39 * @spi_xfer1: @spi_msg1 SPI transfer structure
40 * @spi_xfer2: @spi_msg2 SPI transfer structure
41 *
42 * The @lock ensures that the chip is protected when certain operations are
43 * in progress. When the read or write packet transfer is in progress, most
44 * of the chip registers are not ccessible until the transfer is finished and
45 * the DMA has been de-asserted.
46 */
47struct ks8851_net_spi {
48 struct ks8851_net ks8851;
49 struct mutex lock;
50 struct work_struct tx_work;
51 struct spi_device *spidev;
52 struct spi_message spi_msg1;
53 struct spi_message spi_msg2;
54 struct spi_transfer spi_xfer1;
55 struct spi_transfer spi_xfer2[2];
56};
57
58#define to_ks8851_spi(ks) container_of((ks), struct ks8851_net_spi, ks8851)
59
60/* SPI frame opcodes */
61#define KS_SPIOP_RD 0x00
62#define KS_SPIOP_WR 0x40
63#define KS_SPIOP_RXFIFO 0x80
64#define KS_SPIOP_TXFIFO 0xC0
65
66/* shift for byte-enable data */
67#define BYTE_EN(_x) ((_x) << 2)
68
69/* turn register number and byte-enable mask into data for start of packet */
70#define MK_OP(_byteen, _reg) \
71 (BYTE_EN(_byteen) | (_reg) << (8 + 2) | (_reg) >> 6)
72
73/**
74 * ks8851_lock_spi - register access lock
75 * @ks: The chip state
76 * @flags: Spinlock flags
77 *
78 * Claim chip register access lock
79 */
80static void ks8851_lock_spi(struct ks8851_net *ks, unsigned long *flags)
81{
82 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
83
84 mutex_lock(&kss->lock);
85}
86
87/**
88 * ks8851_unlock_spi - register access unlock
89 * @ks: The chip state
90 * @flags: Spinlock flags
91 *
92 * Release chip register access lock
93 */
94static void ks8851_unlock_spi(struct ks8851_net *ks, unsigned long *flags)
95{
96 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
97
98 mutex_unlock(&kss->lock);
99}
100
101/* SPI register read/write calls.
102 *
103 * All these calls issue SPI transactions to access the chip's registers. They
104 * all require that the necessary lock is held to prevent accesses when the
105 * chip is busy transferring packet data (RX/TX FIFO accesses).
106 */
107
108/**
109 * ks8851_wrreg16_spi - write 16bit register value to chip via SPI
110 * @ks: The chip state
111 * @reg: The register address
112 * @val: The value to write
113 *
114 * Issue a write to put the value @val into the register specified in @reg.
115 */
116static void ks8851_wrreg16_spi(struct ks8851_net *ks, unsigned int reg,
117 unsigned int val)
118{
119 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
120 struct spi_transfer *xfer = &kss->spi_xfer1;
121 struct spi_message *msg = &kss->spi_msg1;
122 __le16 txb[2];
123 int ret;
124
125 txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR);
126 txb[1] = cpu_to_le16(val);
127
128 xfer->tx_buf = txb;
129 xfer->rx_buf = NULL;
130 xfer->len = 4;
131
132 ret = spi_sync(kss->spidev, msg);
133 if (ret < 0)
134 netdev_err(ks->netdev, "spi_sync() failed\n");
135}
136
137/**
138 * ks8851_rdreg - issue read register command and return the data
139 * @ks: The device state
140 * @op: The register address and byte enables in message format.
141 * @rxb: The RX buffer to return the result into
142 * @rxl: The length of data expected.
143 *
144 * This is the low level read call that issues the necessary spi message(s)
145 * to read data from the register specified in @op.
146 */
147static void ks8851_rdreg(struct ks8851_net *ks, unsigned int op,
148 u8 *rxb, unsigned int rxl)
149{
150 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
151 struct spi_transfer *xfer;
152 struct spi_message *msg;
153 __le16 *txb = (__le16 *)ks->txd;
154 u8 *trx = ks->rxd;
155 int ret;
156
157 txb[0] = cpu_to_le16(op | KS_SPIOP_RD);
158
159 if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX) {
160 msg = &kss->spi_msg2;
161 xfer = kss->spi_xfer2;
162
163 xfer->tx_buf = txb;
164 xfer->rx_buf = NULL;
165 xfer->len = 2;
166
167 xfer++;
168 xfer->tx_buf = NULL;
169 xfer->rx_buf = trx;
170 xfer->len = rxl;
171 } else {
172 msg = &kss->spi_msg1;
173 xfer = &kss->spi_xfer1;
174
175 xfer->tx_buf = txb;
176 xfer->rx_buf = trx;
177 xfer->len = rxl + 2;
178 }
179
180 ret = spi_sync(kss->spidev, msg);
181 if (ret < 0)
182 netdev_err(ks->netdev, "read: spi_sync() failed\n");
183 else if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX)
184 memcpy(rxb, trx, rxl);
185 else
186 memcpy(rxb, trx + 2, rxl);
187}
188
189/**
190 * ks8851_rdreg16_spi - read 16 bit register from device via SPI
191 * @ks: The chip information
192 * @reg: The register address
193 *
194 * Read a 16bit register from the chip, returning the result
195 */
196static unsigned int ks8851_rdreg16_spi(struct ks8851_net *ks, unsigned int reg)
197{
198 __le16 rx = 0;
199
200 ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2);
201 return le16_to_cpu(rx);
202}
203
204/**
205 * ks8851_rdfifo_spi - read data from the receive fifo via SPI
206 * @ks: The device state.
207 * @buff: The buffer address
208 * @len: The length of the data to read
209 *
210 * Issue an RXQ FIFO read command and read the @len amount of data from
211 * the FIFO into the buffer specified by @buff.
212 */
213static void ks8851_rdfifo_spi(struct ks8851_net *ks, u8 *buff, unsigned int len)
214{
215 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
216 struct spi_transfer *xfer = kss->spi_xfer2;
217 struct spi_message *msg = &kss->spi_msg2;
218 u8 txb[1];
219 int ret;
220
221 netif_dbg(ks, rx_status, ks->netdev,
222 "%s: %d@%p\n", __func__, len, buff);
223
224 /* set the operation we're issuing */
225 txb[0] = KS_SPIOP_RXFIFO;
226
227 xfer->tx_buf = txb;
228 xfer->rx_buf = NULL;
229 xfer->len = 1;
230
231 xfer++;
232 xfer->rx_buf = buff;
233 xfer->tx_buf = NULL;
234 xfer->len = len;
235
236 ret = spi_sync(kss->spidev, msg);
237 if (ret < 0)
238 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
239}
240
241/**
242 * ks8851_wrfifo_spi - write packet to TX FIFO via SPI
243 * @ks: The device state.
244 * @txp: The sk_buff to transmit.
245 * @irq: IRQ on completion of the packet.
246 *
247 * Send the @txp to the chip. This means creating the relevant packet header
248 * specifying the length of the packet and the other information the chip
249 * needs, such as IRQ on completion. Send the header and the packet data to
250 * the device.
251 */
252static void ks8851_wrfifo_spi(struct ks8851_net *ks, struct sk_buff *txp,
253 bool irq)
254{
255 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
256 struct spi_transfer *xfer = kss->spi_xfer2;
257 struct spi_message *msg = &kss->spi_msg2;
258 unsigned int fid = 0;
259 int ret;
260
261 netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",
262 __func__, txp, txp->len, txp->data, irq);
263
264 fid = ks->fid++;
265 fid &= TXFR_TXFID_MASK;
266
267 if (irq)
268 fid |= TXFR_TXIC; /* irq on completion */
269
270 /* start header at txb[1] to align txw entries */
271 ks->txh.txb[1] = KS_SPIOP_TXFIFO;
272 ks->txh.txw[1] = cpu_to_le16(fid);
273 ks->txh.txw[2] = cpu_to_le16(txp->len);
274
275 xfer->tx_buf = &ks->txh.txb[1];
276 xfer->rx_buf = NULL;
277 xfer->len = 5;
278
279 xfer++;
280 xfer->tx_buf = txp->data;
281 xfer->rx_buf = NULL;
282 xfer->len = ALIGN(txp->len, 4);
283
284 ret = spi_sync(kss->spidev, msg);
285 if (ret < 0)
286 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
287}
288
289/**
290 * ks8851_rx_skb_spi - receive skbuff
291 * @ks: The device state
292 * @skb: The skbuff
293 */
294static void ks8851_rx_skb_spi(struct ks8851_net *ks, struct sk_buff *skb)
295{
296 netif_rx_ni(skb);
297}
298
299/**
300 * ks8851_tx_work - process tx packet(s)
301 * @work: The work strucutre what was scheduled.
302 *
303 * This is called when a number of packets have been scheduled for
304 * transmission and need to be sent to the device.
305 */
306static void ks8851_tx_work(struct work_struct *work)
307{
308 struct ks8851_net_spi *kss;
309 struct ks8851_net *ks;
310 unsigned long flags;
311 struct sk_buff *txb;
312 bool last;
313
314 kss = container_of(work, struct ks8851_net_spi, tx_work);
315 ks = &kss->ks8851;
316 last = skb_queue_empty(&ks->txq);
317
318 ks8851_lock_spi(ks, &flags);
319
320 while (!last) {
321 txb = skb_dequeue(&ks->txq);
322 last = skb_queue_empty(&ks->txq);
323
324 if (txb) {
325 ks8851_wrreg16_spi(ks, KS_RXQCR,
326 ks->rc_rxqcr | RXQCR_SDA);
327 ks8851_wrfifo_spi(ks, txb, last);
328 ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr);
329 ks8851_wrreg16_spi(ks, KS_TXQCR, TXQCR_METFE);
330
331 ks8851_done_tx(ks, txb);
332 }
333 }
334
335 ks8851_unlock_spi(ks, &flags);
336}
337
338/**
339 * ks8851_flush_tx_work_spi - flush outstanding TX work
340 * @ks: The device state
341 */
342static void ks8851_flush_tx_work_spi(struct ks8851_net *ks)
343{
344 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
345
346 flush_work(&kss->tx_work);
347}
348
349/**
350 * calc_txlen - calculate size of message to send packet
351 * @len: Length of data
352 *
353 * Returns the size of the TXFIFO message needed to send
354 * this packet.
355 */
356static unsigned int calc_txlen(unsigned int len)
357{
358 return ALIGN(len + 4, 4);
359}
360
361/**
362 * ks8851_start_xmit_spi - transmit packet using SPI
363 * @skb: The buffer to transmit
364 * @dev: The device used to transmit the packet.
365 *
366 * Called by the network layer to transmit the @skb. Queue the packet for
367 * the device and schedule the necessary work to transmit the packet when
368 * it is free.
369 *
370 * We do this to firstly avoid sleeping with the network device locked,
371 * and secondly so we can round up more than one packet to transmit which
372 * means we can try and avoid generating too many transmit done interrupts.
373 */
374static netdev_tx_t ks8851_start_xmit_spi(struct sk_buff *skb,
375 struct net_device *dev)
376{
377 unsigned int needed = calc_txlen(skb->len);
378 struct ks8851_net *ks = netdev_priv(dev);
379 netdev_tx_t ret = NETDEV_TX_OK;
380 struct ks8851_net_spi *kss;
381
382 kss = to_ks8851_spi(ks);
383
384 netif_dbg(ks, tx_queued, ks->netdev,
385 "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
386
387 spin_lock(&ks->statelock);
388
389 if (needed > ks->tx_space) {
390 netif_stop_queue(dev);
391 ret = NETDEV_TX_BUSY;
392 } else {
393 ks->tx_space -= needed;
394 skb_queue_tail(&ks->txq, skb);
395 }
396
397 spin_unlock(&ks->statelock);
398 schedule_work(&kss->tx_work);
399
400 return ret;
401}
402
403static int ks8851_probe_spi(struct spi_device *spi)
404{
405 struct device *dev = &spi->dev;
406 struct ks8851_net_spi *kss;
407 struct net_device *netdev;
408 struct ks8851_net *ks;
409
410 netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_spi));
411 if (!netdev)
412 return -ENOMEM;
413
414 spi->bits_per_word = 8;
415
416 ks = netdev_priv(netdev);
417
418 ks->lock = ks8851_lock_spi;
419 ks->unlock = ks8851_unlock_spi;
420 ks->rdreg16 = ks8851_rdreg16_spi;
421 ks->wrreg16 = ks8851_wrreg16_spi;
422 ks->rdfifo = ks8851_rdfifo_spi;
423 ks->wrfifo = ks8851_wrfifo_spi;
424 ks->start_xmit = ks8851_start_xmit_spi;
425 ks->rx_skb = ks8851_rx_skb_spi;
426 ks->flush_tx_work = ks8851_flush_tx_work_spi;
427
428#define STD_IRQ (IRQ_LCI | /* Link Change */ \
429 IRQ_TXI | /* TX done */ \
430 IRQ_RXI | /* RX done */ \
431 IRQ_SPIBEI | /* SPI bus error */ \
432 IRQ_TXPSI | /* TX process stop */ \
433 IRQ_RXPSI) /* RX process stop */
434 ks->rc_ier = STD_IRQ;
435
436 kss = to_ks8851_spi(ks);
437
438 kss->spidev = spi;
439 mutex_init(&kss->lock);
440 INIT_WORK(&kss->tx_work, ks8851_tx_work);
441
442 /* initialise pre-made spi transfer messages */
443 spi_message_init(&kss->spi_msg1);
444 spi_message_add_tail(&kss->spi_xfer1, &kss->spi_msg1);
445
446 spi_message_init(&kss->spi_msg2);
447 spi_message_add_tail(&kss->spi_xfer2[0], &kss->spi_msg2);
448 spi_message_add_tail(&kss->spi_xfer2[1], &kss->spi_msg2);
449
450 netdev->irq = spi->irq;
451
452 return ks8851_probe_common(netdev, dev, msg_enable);
453}
454
455static int ks8851_remove_spi(struct spi_device *spi)
456{
457 return ks8851_remove_common(&spi->dev);
458}
459
460static const struct of_device_id ks8851_match_table[] = {
461 { .compatible = "micrel,ks8851" },
462 { }
463};
464MODULE_DEVICE_TABLE(of, ks8851_match_table);
465
466static struct spi_driver ks8851_driver = {
467 .driver = {
468 .name = "ks8851",
469 .of_match_table = ks8851_match_table,
470 .pm = &ks8851_pm_ops,
471 },
472 .probe = ks8851_probe_spi,
473 .remove = ks8851_remove_spi,
474};
475module_spi_driver(ks8851_driver);
476
477MODULE_DESCRIPTION("KS8851 Network driver");
478MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
479MODULE_LICENSE("GPL");
480
481module_param_named(message, msg_enable, int, 0);
482MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");
483MODULE_ALIAS("spi:ks8851");