1 // SPDX-License-Identifier: GPL-2.0-only
2 /* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
3 *
4 * Copyright(C) Timesys Corporation 2016
5 *
6 * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
7 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
8 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
9 * Copyright 2006 Arcom Control Systems Ltd.
10 *
11 * Based on CAN bus driver for the CCAN controller written by
12 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
13 * - Simon Kallweit, intefo AG
14 * Copyright 2007
15 */
16
17 #include <linux/can/core.h>
18 #include <linux/can/dev.h>
19 #include <linux/clk.h>
20 #include <linux/completion.h>
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/ethtool.h>
24 #include <linux/freezer.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/mod_devicetable.h>
29 #include <linux/module.h>
30 #include <linux/netdevice.h>
31 #include <linux/platform_device.h>
32 #include <linux/property.h>
33 #include <linux/regulator/consumer.h>
34 #include <linux/slab.h>
35 #include <linux/spi/spi.h>
36 #include <linux/uaccess.h>
37
38 #define HI3110_MASTER_RESET 0x56
39 #define HI3110_READ_CTRL0 0xD2
40 #define HI3110_READ_CTRL1 0xD4
41 #define HI3110_READ_STATF 0xE2
42 #define HI3110_WRITE_CTRL0 0x14
43 #define HI3110_WRITE_CTRL1 0x16
44 #define HI3110_WRITE_INTE 0x1C
45 #define HI3110_WRITE_BTR0 0x18
46 #define HI3110_WRITE_BTR1 0x1A
47 #define HI3110_READ_BTR0 0xD6
48 #define HI3110_READ_BTR1 0xD8
49 #define HI3110_READ_INTF 0xDE
50 #define HI3110_READ_ERR 0xDC
51 #define HI3110_READ_FIFO_WOTIME 0x48
52 #define HI3110_WRITE_FIFO 0x12
53 #define HI3110_READ_MESSTAT 0xDA
54 #define HI3110_READ_REC 0xEA
55 #define HI3110_READ_TEC 0xEC
56
57 #define HI3110_CTRL0_MODE_MASK (7 << 5)
58 #define HI3110_CTRL0_NORMAL_MODE (0 << 5)
59 #define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
60 #define HI3110_CTRL0_MONITOR_MODE (2 << 5)
61 #define HI3110_CTRL0_SLEEP_MODE (3 << 5)
62 #define HI3110_CTRL0_INIT_MODE (4 << 5)
63
64 #define HI3110_CTRL1_TXEN BIT(7)
65
66 #define HI3110_INT_RXTMP BIT(7)
67 #define HI3110_INT_RXFIFO BIT(6)
68 #define HI3110_INT_TXCPLT BIT(5)
69 #define HI3110_INT_BUSERR BIT(4)
70 #define HI3110_INT_MCHG BIT(3)
71 #define HI3110_INT_WAKEUP BIT(2)
72 #define HI3110_INT_F1MESS BIT(1)
73 #define HI3110_INT_F0MESS BIT(0)
74
75 #define HI3110_ERR_BUSOFF BIT(7)
76 #define HI3110_ERR_TXERRP BIT(6)
77 #define HI3110_ERR_RXERRP BIT(5)
78 #define HI3110_ERR_BITERR BIT(4)
79 #define HI3110_ERR_FRMERR BIT(3)
80 #define HI3110_ERR_CRCERR BIT(2)
81 #define HI3110_ERR_ACKERR BIT(1)
82 #define HI3110_ERR_STUFERR BIT(0)
83 #define HI3110_ERR_PROTOCOL_MASK (0x1F)
84 #define HI3110_ERR_PASSIVE_MASK (0x60)
85
86 #define HI3110_STAT_RXFMTY BIT(1)
87 #define HI3110_STAT_BUSOFF BIT(2)
88 #define HI3110_STAT_ERRP BIT(3)
89 #define HI3110_STAT_ERRW BIT(4)
90 #define HI3110_STAT_TXMTY BIT(7)
91
92 #define HI3110_BTR0_SJW_SHIFT 6
93 #define HI3110_BTR0_BRP_SHIFT 0
94
95 #define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
96 #define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
97 #define HI3110_BTR1_TSEG2_SHIFT 4
98 #define HI3110_BTR1_TSEG1_SHIFT 0
99
100 #define HI3110_FIFO_WOTIME_TAG_OFF 0
101 #define HI3110_FIFO_WOTIME_ID_OFF 1
102 #define HI3110_FIFO_WOTIME_DLC_OFF 5
103 #define HI3110_FIFO_WOTIME_DAT_OFF 6
104
105 #define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
106 #define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
107
108 #define HI3110_FIFO_TAG_OFF 0
109 #define HI3110_FIFO_ID_OFF 1
110 #define HI3110_FIFO_STD_DLC_OFF 3
111 #define HI3110_FIFO_STD_DATA_OFF 4
112 #define HI3110_FIFO_EXT_DLC_OFF 5
113 #define HI3110_FIFO_EXT_DATA_OFF 6
114
115 #define HI3110_CAN_MAX_DATA_LEN 8
116 #define HI3110_RX_BUF_LEN 15
117 #define HI3110_TX_STD_BUF_LEN 12
118 #define HI3110_TX_EXT_BUF_LEN 14
119 #define HI3110_CAN_FRAME_MAX_BITS 128
120 #define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
121
122 #define HI3110_TX_ECHO_SKB_MAX 1
123
124 #define HI3110_OST_DELAY_MS (10)
125
126 #define DEVICE_NAME "hi3110"
127
128 static const struct can_bittiming_const hi3110_bittiming_const = {
129 .name = DEVICE_NAME,
130 .tseg1_min = 2,
131 .tseg1_max = 16,
132 .tseg2_min = 2,
133 .tseg2_max = 8,
134 .sjw_max = 4,
135 .brp_min = 1,
136 .brp_max = 64,
137 .brp_inc = 1,
138 };
139
140 enum hi3110_model {
141 CAN_HI3110_HI3110 = 0x3110,
142 };
143
144 struct hi3110_priv {
145 struct can_priv can;
146 struct net_device *net;
147 struct spi_device *spi;
148 enum hi3110_model model;
149
150 struct mutex hi3110_lock; /* SPI device lock */
151
152 u8 *spi_tx_buf;
153 u8 *spi_rx_buf;
154
155 struct sk_buff *tx_skb;
156
157 struct workqueue_struct *wq;
158 struct work_struct tx_work;
159 struct work_struct restart_work;
160
161 int force_quit;
162 int after_suspend;
163 #define HI3110_AFTER_SUSPEND_UP 1
164 #define HI3110_AFTER_SUSPEND_DOWN 2
165 #define HI3110_AFTER_SUSPEND_POWER 4
166 #define HI3110_AFTER_SUSPEND_RESTART 8
167 int restart_tx;
168 bool tx_busy;
169
170 struct regulator *power;
171 struct regulator *transceiver;
172 struct clk *clk;
173 };
174
hi3110_clean(struct net_device * net)175 static void hi3110_clean(struct net_device *net)
176 {
177 struct hi3110_priv *priv = netdev_priv(net);
178
179 if (priv->tx_skb || priv->tx_busy)
180 net->stats.tx_errors++;
181 dev_kfree_skb(priv->tx_skb);
182 if (priv->tx_busy)
183 can_free_echo_skb(priv->net, 0, NULL);
184 priv->tx_skb = NULL;
185 priv->tx_busy = false;
186 }
187
188 /* Note about handling of error return of hi3110_spi_trans: accessing
189 * registers via SPI is not really different conceptually than using
190 * normal I/O assembler instructions, although it's much more
191 * complicated from a practical POV. So it's not advisable to always
192 * check the return value of this function. Imagine that every
193 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
194 * error();", it would be a great mess (well there are some situation
195 * when exception handling C++ like could be useful after all). So we
196 * just check that transfers are OK at the beginning of our
197 * conversation with the chip and to avoid doing really nasty things
198 * (like injecting bogus packets in the network stack).
199 */
hi3110_spi_trans(struct spi_device * spi,int len)200 static int hi3110_spi_trans(struct spi_device *spi, int len)
201 {
202 struct hi3110_priv *priv = spi_get_drvdata(spi);
203 struct spi_transfer t = {
204 .tx_buf = priv->spi_tx_buf,
205 .rx_buf = priv->spi_rx_buf,
206 .len = len,
207 .cs_change = 0,
208 };
209 struct spi_message m;
210 int ret;
211
212 spi_message_init(&m);
213 spi_message_add_tail(&t, &m);
214
215 ret = spi_sync(spi, &m);
216
217 if (ret)
218 dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
219 return ret;
220 }
221
hi3110_cmd(struct spi_device * spi,u8 command)222 static int hi3110_cmd(struct spi_device *spi, u8 command)
223 {
224 struct hi3110_priv *priv = spi_get_drvdata(spi);
225
226 priv->spi_tx_buf[0] = command;
227 dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
228
229 return hi3110_spi_trans(spi, 1);
230 }
231
hi3110_read(struct spi_device * spi,u8 command)232 static u8 hi3110_read(struct spi_device *spi, u8 command)
233 {
234 struct hi3110_priv *priv = spi_get_drvdata(spi);
235 u8 val = 0;
236
237 priv->spi_tx_buf[0] = command;
238 hi3110_spi_trans(spi, 2);
239 val = priv->spi_rx_buf[1];
240
241 return val;
242 }
243
hi3110_write(struct spi_device * spi,u8 reg,u8 val)244 static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
245 {
246 struct hi3110_priv *priv = spi_get_drvdata(spi);
247
248 priv->spi_tx_buf[0] = reg;
249 priv->spi_tx_buf[1] = val;
250 hi3110_spi_trans(spi, 2);
251 }
252
hi3110_hw_tx_frame(struct spi_device * spi,u8 * buf,int len)253 static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
254 {
255 struct hi3110_priv *priv = spi_get_drvdata(spi);
256
257 priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
258 memcpy(priv->spi_tx_buf + 1, buf, len);
259 hi3110_spi_trans(spi, len + 1);
260 }
261
hi3110_hw_tx(struct spi_device * spi,struct can_frame * frame)262 static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
263 {
264 u8 buf[HI3110_TX_EXT_BUF_LEN];
265
266 buf[HI3110_FIFO_TAG_OFF] = 0;
267
268 if (frame->can_id & CAN_EFF_FLAG) {
269 /* Extended frame */
270 buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
271 buf[HI3110_FIFO_ID_OFF + 1] =
272 (((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
273 HI3110_EFF_FLAGS |
274 (((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
275 buf[HI3110_FIFO_ID_OFF + 2] =
276 (frame->can_id & CAN_EFF_MASK) >> 7;
277 buf[HI3110_FIFO_ID_OFF + 3] =
278 ((frame->can_id & CAN_EFF_MASK) << 1) |
279 ((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
280
281 buf[HI3110_FIFO_EXT_DLC_OFF] = frame->len;
282
283 memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
284 frame->data, frame->len);
285
286 hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
287 (HI3110_CAN_MAX_DATA_LEN - frame->len));
288 } else {
289 /* Standard frame */
290 buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_SFF_MASK) >> 3;
291 buf[HI3110_FIFO_ID_OFF + 1] =
292 ((frame->can_id & CAN_SFF_MASK) << 5) |
293 ((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
294
295 buf[HI3110_FIFO_STD_DLC_OFF] = frame->len;
296
297 memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
298 frame->data, frame->len);
299
300 hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
301 (HI3110_CAN_MAX_DATA_LEN - frame->len));
302 }
303 }
304
hi3110_hw_rx_frame(struct spi_device * spi,u8 * buf)305 static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
306 {
307 struct hi3110_priv *priv = spi_get_drvdata(spi);
308
309 priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
310 hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
311 memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
312 }
313
hi3110_hw_rx(struct spi_device * spi)314 static void hi3110_hw_rx(struct spi_device *spi)
315 {
316 struct hi3110_priv *priv = spi_get_drvdata(spi);
317 struct sk_buff *skb;
318 struct can_frame *frame;
319 u8 buf[HI3110_RX_BUF_LEN - 1];
320
321 skb = alloc_can_skb(priv->net, &frame);
322 if (!skb) {
323 priv->net->stats.rx_dropped++;
324 return;
325 }
326
327 hi3110_hw_rx_frame(spi, buf);
328 if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
329 /* IDE is recessive (1), indicating extended 29-bit frame */
330 frame->can_id = CAN_EFF_FLAG;
331 frame->can_id |=
332 (buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
333 (((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
334 ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
335 (buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
336 (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
337 } else {
338 /* IDE is dominant (0), frame indicating standard 11-bit */
339 frame->can_id =
340 (buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
341 ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
342 }
343
344 /* Data length */
345 frame->len = can_cc_dlc2len(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
346
347 if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR) {
348 frame->can_id |= CAN_RTR_FLAG;
349 } else {
350 memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
351 frame->len);
352
353 priv->net->stats.rx_bytes += frame->len;
354 }
355 priv->net->stats.rx_packets++;
356
357 netif_rx(skb);
358 }
359
hi3110_hw_sleep(struct spi_device * spi)360 static void hi3110_hw_sleep(struct spi_device *spi)
361 {
362 hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
363 }
364
hi3110_hard_start_xmit(struct sk_buff * skb,struct net_device * net)365 static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
366 struct net_device *net)
367 {
368 struct hi3110_priv *priv = netdev_priv(net);
369 struct spi_device *spi = priv->spi;
370
371 if (priv->tx_skb || priv->tx_busy) {
372 dev_err(&spi->dev, "hard_xmit called while tx busy\n");
373 return NETDEV_TX_BUSY;
374 }
375
376 if (can_dev_dropped_skb(net, skb))
377 return NETDEV_TX_OK;
378
379 netif_stop_queue(net);
380 priv->tx_skb = skb;
381 queue_work(priv->wq, &priv->tx_work);
382
383 return NETDEV_TX_OK;
384 }
385
hi3110_do_set_mode(struct net_device * net,enum can_mode mode)386 static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
387 {
388 struct hi3110_priv *priv = netdev_priv(net);
389
390 switch (mode) {
391 case CAN_MODE_START:
392 hi3110_clean(net);
393 /* We have to delay work since SPI I/O may sleep */
394 priv->can.state = CAN_STATE_ERROR_ACTIVE;
395 priv->restart_tx = 1;
396 if (priv->can.restart_ms == 0)
397 priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
398 queue_work(priv->wq, &priv->restart_work);
399 break;
400 default:
401 return -EOPNOTSUPP;
402 }
403
404 return 0;
405 }
406
hi3110_get_berr_counter(const struct net_device * net,struct can_berr_counter * bec)407 static int hi3110_get_berr_counter(const struct net_device *net,
408 struct can_berr_counter *bec)
409 {
410 struct hi3110_priv *priv = netdev_priv(net);
411 struct spi_device *spi = priv->spi;
412
413 mutex_lock(&priv->hi3110_lock);
414 bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
415 bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
416 mutex_unlock(&priv->hi3110_lock);
417
418 return 0;
419 }
420
hi3110_set_normal_mode(struct spi_device * spi)421 static int hi3110_set_normal_mode(struct spi_device *spi)
422 {
423 struct hi3110_priv *priv = spi_get_drvdata(spi);
424 u8 reg = 0;
425
426 hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
427 HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
428
429 /* Enable TX */
430 hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
431
432 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
433 reg = HI3110_CTRL0_LOOPBACK_MODE;
434 else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
435 reg = HI3110_CTRL0_MONITOR_MODE;
436 else
437 reg = HI3110_CTRL0_NORMAL_MODE;
438
439 hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
440
441 /* Wait for the device to enter the mode */
442 mdelay(HI3110_OST_DELAY_MS);
443 reg = hi3110_read(spi, HI3110_READ_CTRL0);
444 if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
445 return -EBUSY;
446
447 priv->can.state = CAN_STATE_ERROR_ACTIVE;
448 return 0;
449 }
450
hi3110_do_set_bittiming(struct net_device * net)451 static int hi3110_do_set_bittiming(struct net_device *net)
452 {
453 struct hi3110_priv *priv = netdev_priv(net);
454 struct can_bittiming *bt = &priv->can.bittiming;
455 struct spi_device *spi = priv->spi;
456
457 hi3110_write(spi, HI3110_WRITE_BTR0,
458 ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
459 ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
460
461 hi3110_write(spi, HI3110_WRITE_BTR1,
462 (priv->can.ctrlmode &
463 CAN_CTRLMODE_3_SAMPLES ?
464 HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
465 ((bt->phase_seg1 + bt->prop_seg - 1)
466 << HI3110_BTR1_TSEG1_SHIFT) |
467 ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
468
469 dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
470 hi3110_read(spi, HI3110_READ_BTR0),
471 hi3110_read(spi, HI3110_READ_BTR1));
472
473 return 0;
474 }
475
hi3110_setup(struct net_device * net)476 static int hi3110_setup(struct net_device *net)
477 {
478 hi3110_do_set_bittiming(net);
479 return 0;
480 }
481
hi3110_hw_reset(struct spi_device * spi)482 static int hi3110_hw_reset(struct spi_device *spi)
483 {
484 u8 reg;
485 int ret;
486
487 /* Wait for oscillator startup timer after power up */
488 mdelay(HI3110_OST_DELAY_MS);
489
490 ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
491 if (ret)
492 return ret;
493
494 /* Wait for oscillator startup timer after reset */
495 mdelay(HI3110_OST_DELAY_MS);
496
497 reg = hi3110_read(spi, HI3110_READ_CTRL0);
498 if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
499 return -ENODEV;
500
501 /* As per the datasheet it appears the error flags are
502 * not cleared on reset. Explicitly clear them by performing a read
503 */
504 hi3110_read(spi, HI3110_READ_ERR);
505
506 return 0;
507 }
508
hi3110_hw_probe(struct spi_device * spi)509 static int hi3110_hw_probe(struct spi_device *spi)
510 {
511 u8 statf;
512
513 hi3110_hw_reset(spi);
514
515 /* Confirm correct operation by checking against reset values
516 * in datasheet
517 */
518 statf = hi3110_read(spi, HI3110_READ_STATF);
519
520 dev_dbg(&spi->dev, "statf: %02X\n", statf);
521
522 if (statf != 0x82)
523 return -ENODEV;
524
525 return 0;
526 }
527
hi3110_power_enable(struct regulator * reg,int enable)528 static int hi3110_power_enable(struct regulator *reg, int enable)
529 {
530 if (IS_ERR_OR_NULL(reg))
531 return 0;
532
533 if (enable)
534 return regulator_enable(reg);
535 else
536 return regulator_disable(reg);
537 }
538
hi3110_stop(struct net_device * net)539 static int hi3110_stop(struct net_device *net)
540 {
541 struct hi3110_priv *priv = netdev_priv(net);
542 struct spi_device *spi = priv->spi;
543
544 close_candev(net);
545
546 priv->force_quit = 1;
547 free_irq(spi->irq, priv);
548 destroy_workqueue(priv->wq);
549 priv->wq = NULL;
550
551 mutex_lock(&priv->hi3110_lock);
552
553 /* Disable transmit, interrupts and clear flags */
554 hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
555 hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
556 hi3110_read(spi, HI3110_READ_INTF);
557
558 hi3110_clean(net);
559
560 hi3110_hw_sleep(spi);
561
562 hi3110_power_enable(priv->transceiver, 0);
563
564 priv->can.state = CAN_STATE_STOPPED;
565
566 mutex_unlock(&priv->hi3110_lock);
567
568 return 0;
569 }
570
hi3110_tx_work_handler(struct work_struct * ws)571 static void hi3110_tx_work_handler(struct work_struct *ws)
572 {
573 struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
574 tx_work);
575 struct spi_device *spi = priv->spi;
576 struct net_device *net = priv->net;
577 struct can_frame *frame;
578
579 mutex_lock(&priv->hi3110_lock);
580 if (priv->tx_skb) {
581 if (priv->can.state == CAN_STATE_BUS_OFF) {
582 hi3110_clean(net);
583 } else {
584 frame = (struct can_frame *)priv->tx_skb->data;
585 hi3110_hw_tx(spi, frame);
586 priv->tx_busy = true;
587 can_put_echo_skb(priv->tx_skb, net, 0, 0);
588 priv->tx_skb = NULL;
589 }
590 }
591 mutex_unlock(&priv->hi3110_lock);
592 }
593
hi3110_restart_work_handler(struct work_struct * ws)594 static void hi3110_restart_work_handler(struct work_struct *ws)
595 {
596 struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
597 restart_work);
598 struct spi_device *spi = priv->spi;
599 struct net_device *net = priv->net;
600
601 mutex_lock(&priv->hi3110_lock);
602 if (priv->after_suspend) {
603 hi3110_hw_reset(spi);
604 hi3110_setup(net);
605 if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
606 hi3110_set_normal_mode(spi);
607 } else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
608 netif_device_attach(net);
609 hi3110_clean(net);
610 hi3110_set_normal_mode(spi);
611 netif_wake_queue(net);
612 } else {
613 hi3110_hw_sleep(spi);
614 }
615 priv->after_suspend = 0;
616 priv->force_quit = 0;
617 }
618
619 if (priv->restart_tx) {
620 priv->restart_tx = 0;
621 hi3110_hw_reset(spi);
622 hi3110_setup(net);
623 hi3110_clean(net);
624 hi3110_set_normal_mode(spi);
625 netif_wake_queue(net);
626 }
627 mutex_unlock(&priv->hi3110_lock);
628 }
629
hi3110_can_ist(int irq,void * dev_id)630 static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
631 {
632 struct hi3110_priv *priv = dev_id;
633 struct spi_device *spi = priv->spi;
634 struct net_device *net = priv->net;
635
636 mutex_lock(&priv->hi3110_lock);
637
638 while (!priv->force_quit) {
639 enum can_state new_state;
640 u8 intf, eflag, statf;
641
642 while (!(HI3110_STAT_RXFMTY &
643 (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
644 hi3110_hw_rx(spi);
645 }
646
647 intf = hi3110_read(spi, HI3110_READ_INTF);
648 eflag = hi3110_read(spi, HI3110_READ_ERR);
649 /* Update can state */
650 if (eflag & HI3110_ERR_BUSOFF)
651 new_state = CAN_STATE_BUS_OFF;
652 else if (eflag & HI3110_ERR_PASSIVE_MASK)
653 new_state = CAN_STATE_ERROR_PASSIVE;
654 else if (statf & HI3110_STAT_ERRW)
655 new_state = CAN_STATE_ERROR_WARNING;
656 else
657 new_state = CAN_STATE_ERROR_ACTIVE;
658
659 if (new_state != priv->can.state) {
660 struct can_frame *cf;
661 struct sk_buff *skb;
662 enum can_state rx_state, tx_state;
663 u8 rxerr, txerr;
664
665 skb = alloc_can_err_skb(net, &cf);
666 if (!skb)
667 break;
668
669 txerr = hi3110_read(spi, HI3110_READ_TEC);
670 rxerr = hi3110_read(spi, HI3110_READ_REC);
671 tx_state = txerr >= rxerr ? new_state : 0;
672 rx_state = txerr <= rxerr ? new_state : 0;
673 can_change_state(net, cf, tx_state, rx_state);
674 netif_rx(skb);
675
676 if (new_state == CAN_STATE_BUS_OFF) {
677 can_bus_off(net);
678 if (priv->can.restart_ms == 0) {
679 priv->force_quit = 1;
680 hi3110_hw_sleep(spi);
681 break;
682 }
683 } else {
684 cf->can_id |= CAN_ERR_CNT;
685 cf->data[6] = txerr;
686 cf->data[7] = rxerr;
687 }
688 }
689
690 /* Update bus errors */
691 if ((intf & HI3110_INT_BUSERR) &&
692 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
693 struct can_frame *cf;
694 struct sk_buff *skb;
695
696 /* Check for protocol errors */
697 if (eflag & HI3110_ERR_PROTOCOL_MASK) {
698 skb = alloc_can_err_skb(net, &cf);
699 if (!skb)
700 break;
701
702 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
703 priv->can.can_stats.bus_error++;
704 priv->net->stats.rx_errors++;
705 if (eflag & HI3110_ERR_BITERR)
706 cf->data[2] |= CAN_ERR_PROT_BIT;
707 else if (eflag & HI3110_ERR_FRMERR)
708 cf->data[2] |= CAN_ERR_PROT_FORM;
709 else if (eflag & HI3110_ERR_STUFERR)
710 cf->data[2] |= CAN_ERR_PROT_STUFF;
711 else if (eflag & HI3110_ERR_CRCERR)
712 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
713 else if (eflag & HI3110_ERR_ACKERR)
714 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
715
716 cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
717 cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
718 netdev_dbg(priv->net, "Bus Error\n");
719 netif_rx(skb);
720 }
721 }
722
723 if (priv->tx_busy && statf & HI3110_STAT_TXMTY) {
724 net->stats.tx_packets++;
725 net->stats.tx_bytes += can_get_echo_skb(net, 0, NULL);
726 priv->tx_busy = false;
727 netif_wake_queue(net);
728 }
729
730 if (intf == 0)
731 break;
732 }
733 mutex_unlock(&priv->hi3110_lock);
734 return IRQ_HANDLED;
735 }
736
hi3110_open(struct net_device * net)737 static int hi3110_open(struct net_device *net)
738 {
739 struct hi3110_priv *priv = netdev_priv(net);
740 struct spi_device *spi = priv->spi;
741 unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_HIGH;
742 int ret;
743
744 ret = open_candev(net);
745 if (ret)
746 return ret;
747
748 mutex_lock(&priv->hi3110_lock);
749 hi3110_power_enable(priv->transceiver, 1);
750
751 priv->force_quit = 0;
752 priv->tx_skb = NULL;
753 priv->tx_busy = false;
754
755 ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
756 flags, DEVICE_NAME, priv);
757 if (ret) {
758 dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
759 goto out_close;
760 }
761
762 priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
763 0);
764 if (!priv->wq) {
765 ret = -ENOMEM;
766 goto out_free_irq;
767 }
768 INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
769 INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
770
771 ret = hi3110_hw_reset(spi);
772 if (ret)
773 goto out_free_wq;
774
775 ret = hi3110_setup(net);
776 if (ret)
777 goto out_free_wq;
778
779 ret = hi3110_set_normal_mode(spi);
780 if (ret)
781 goto out_free_wq;
782
783 netif_wake_queue(net);
784 mutex_unlock(&priv->hi3110_lock);
785
786 return 0;
787
788 out_free_wq:
789 destroy_workqueue(priv->wq);
790 out_free_irq:
791 free_irq(spi->irq, priv);
792 hi3110_hw_sleep(spi);
793 out_close:
794 hi3110_power_enable(priv->transceiver, 0);
795 close_candev(net);
796 mutex_unlock(&priv->hi3110_lock);
797 return ret;
798 }
799
800 static const struct net_device_ops hi3110_netdev_ops = {
801 .ndo_open = hi3110_open,
802 .ndo_stop = hi3110_stop,
803 .ndo_start_xmit = hi3110_hard_start_xmit,
804 };
805
806 static const struct ethtool_ops hi3110_ethtool_ops = {
807 .get_ts_info = ethtool_op_get_ts_info,
808 };
809
810 static const struct of_device_id hi3110_of_match[] = {
811 {
812 .compatible = "holt,hi3110",
813 .data = (void *)CAN_HI3110_HI3110,
814 },
815 { }
816 };
817 MODULE_DEVICE_TABLE(of, hi3110_of_match);
818
819 static const struct spi_device_id hi3110_id_table[] = {
820 {
821 .name = "hi3110",
822 .driver_data = (kernel_ulong_t)CAN_HI3110_HI3110,
823 },
824 { }
825 };
826 MODULE_DEVICE_TABLE(spi, hi3110_id_table);
827
hi3110_can_probe(struct spi_device * spi)828 static int hi3110_can_probe(struct spi_device *spi)
829 {
830 struct device *dev = &spi->dev;
831 struct net_device *net;
832 struct hi3110_priv *priv;
833 struct clk *clk;
834 u32 freq;
835 int ret;
836
837 clk = devm_clk_get_optional(&spi->dev, NULL);
838 if (IS_ERR(clk))
839 return dev_err_probe(dev, PTR_ERR(clk), "no CAN clock source defined\n");
840
841 if (clk) {
842 freq = clk_get_rate(clk);
843 } else {
844 ret = device_property_read_u32(dev, "clock-frequency", &freq);
845 if (ret)
846 return dev_err_probe(dev, ret, "Failed to get clock-frequency!\n");
847 }
848
849 /* Sanity check */
850 if (freq > 40000000)
851 return -ERANGE;
852
853 /* Allocate can/net device */
854 net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
855 if (!net)
856 return -ENOMEM;
857
858 ret = clk_prepare_enable(clk);
859 if (ret)
860 goto out_free;
861
862 net->netdev_ops = &hi3110_netdev_ops;
863 net->ethtool_ops = &hi3110_ethtool_ops;
864 net->flags |= IFF_ECHO;
865
866 priv = netdev_priv(net);
867 priv->can.bittiming_const = &hi3110_bittiming_const;
868 priv->can.do_set_mode = hi3110_do_set_mode;
869 priv->can.do_get_berr_counter = hi3110_get_berr_counter;
870 priv->can.clock.freq = freq / 2;
871 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
872 CAN_CTRLMODE_LOOPBACK |
873 CAN_CTRLMODE_LISTENONLY |
874 CAN_CTRLMODE_BERR_REPORTING;
875
876 priv->model = (enum hi3110_model)(uintptr_t)spi_get_device_match_data(spi);
877 priv->net = net;
878 priv->clk = clk;
879
880 spi_set_drvdata(spi, priv);
881
882 /* Configure the SPI bus */
883 spi->bits_per_word = 8;
884 ret = spi_setup(spi);
885 if (ret)
886 goto out_clk;
887
888 priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
889 priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
890 if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
891 (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
892 ret = -EPROBE_DEFER;
893 goto out_clk;
894 }
895
896 ret = hi3110_power_enable(priv->power, 1);
897 if (ret)
898 goto out_clk;
899
900 priv->spi = spi;
901 mutex_init(&priv->hi3110_lock);
902
903 priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
904 GFP_KERNEL);
905 if (!priv->spi_tx_buf) {
906 ret = -ENOMEM;
907 goto error_probe;
908 }
909 priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
910 GFP_KERNEL);
911
912 if (!priv->spi_rx_buf) {
913 ret = -ENOMEM;
914 goto error_probe;
915 }
916
917 SET_NETDEV_DEV(net, &spi->dev);
918
919 ret = hi3110_hw_probe(spi);
920 if (ret) {
921 dev_err_probe(dev, ret, "Cannot initialize %x. Wrong wiring?\n", priv->model);
922 goto error_probe;
923 }
924 hi3110_hw_sleep(spi);
925
926 ret = register_candev(net);
927 if (ret)
928 goto error_probe;
929
930 netdev_info(net, "%x successfully initialized.\n", priv->model);
931
932 return 0;
933
934 error_probe:
935 hi3110_power_enable(priv->power, 0);
936
937 out_clk:
938 clk_disable_unprepare(clk);
939
940 out_free:
941 free_candev(net);
942
943 return dev_err_probe(dev, ret, "Probe failed\n");
944 }
945
hi3110_can_remove(struct spi_device * spi)946 static void hi3110_can_remove(struct spi_device *spi)
947 {
948 struct hi3110_priv *priv = spi_get_drvdata(spi);
949 struct net_device *net = priv->net;
950
951 unregister_candev(net);
952
953 hi3110_power_enable(priv->power, 0);
954
955 clk_disable_unprepare(priv->clk);
956
957 free_candev(net);
958 }
959
hi3110_can_suspend(struct device * dev)960 static int __maybe_unused hi3110_can_suspend(struct device *dev)
961 {
962 struct spi_device *spi = to_spi_device(dev);
963 struct hi3110_priv *priv = spi_get_drvdata(spi);
964 struct net_device *net = priv->net;
965
966 priv->force_quit = 1;
967 disable_irq(spi->irq);
968
969 /* Note: at this point neither IST nor workqueues are running.
970 * open/stop cannot be called anyway so locking is not needed
971 */
972 if (netif_running(net)) {
973 netif_device_detach(net);
974
975 hi3110_hw_sleep(spi);
976 hi3110_power_enable(priv->transceiver, 0);
977 priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
978 } else {
979 priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
980 }
981
982 if (!IS_ERR_OR_NULL(priv->power)) {
983 regulator_disable(priv->power);
984 priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
985 }
986
987 return 0;
988 }
989
hi3110_can_resume(struct device * dev)990 static int __maybe_unused hi3110_can_resume(struct device *dev)
991 {
992 struct spi_device *spi = to_spi_device(dev);
993 struct hi3110_priv *priv = spi_get_drvdata(spi);
994
995 if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
996 hi3110_power_enable(priv->power, 1);
997
998 if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
999 hi3110_power_enable(priv->transceiver, 1);
1000 queue_work(priv->wq, &priv->restart_work);
1001 } else {
1002 priv->after_suspend = 0;
1003 }
1004
1005 priv->force_quit = 0;
1006 enable_irq(spi->irq);
1007 return 0;
1008 }
1009
1010 static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);
1011
1012 static struct spi_driver hi3110_can_driver = {
1013 .driver = {
1014 .name = DEVICE_NAME,
1015 .of_match_table = hi3110_of_match,
1016 .pm = &hi3110_can_pm_ops,
1017 },
1018 .id_table = hi3110_id_table,
1019 .probe = hi3110_can_probe,
1020 .remove = hi3110_can_remove,
1021 };
1022
1023 module_spi_driver(hi3110_can_driver);
1024
1025 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
1026 MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
1027 MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
1028 MODULE_LICENSE("GPL v2");
1029