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can: hi311x: Use level-triggered interrupt
[linux/fpc-iii.git] / drivers / net / can / spi / hi311x.c
blobddaf46239e39e92337a4ed54ecb3feb1ab94cc59
1 /* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
2 *
3 * Copyright(C) Timesys Corporation 2016
4 *
5 * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
6 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
7 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
8 * Copyright 2006 Arcom Control Systems Ltd.
9 *
10 * Based on CAN bus driver for the CCAN controller written by
11 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
12 * - Simon Kallweit, intefo AG
13 * Copyright 2007
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 as
17 * published by the Free Software Foundation.
18 */
19
20 #include <linux/can/core.h>
21 #include <linux/can/dev.h>
22 #include <linux/can/led.h>
23 #include <linux/clk.h>
24 #include <linux/completion.h>
25 #include <linux/delay.h>
26 #include <linux/device.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/freezer.h>
29 #include <linux/interrupt.h>
30 #include <linux/io.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/netdevice.h>
34 #include <linux/of.h>
35 #include <linux/of_device.h>
36 #include <linux/platform_device.h>
37 #include <linux/regulator/consumer.h>
38 #include <linux/slab.h>
39 #include <linux/spi/spi.h>
40 #include <linux/uaccess.h>
41
42 #define HI3110_MASTER_RESET 0x56
43 #define HI3110_READ_CTRL0 0xD2
44 #define HI3110_READ_CTRL1 0xD4
45 #define HI3110_READ_STATF 0xE2
46 #define HI3110_WRITE_CTRL0 0x14
47 #define HI3110_WRITE_CTRL1 0x16
48 #define HI3110_WRITE_INTE 0x1C
49 #define HI3110_WRITE_BTR0 0x18
50 #define HI3110_WRITE_BTR1 0x1A
51 #define HI3110_READ_BTR0 0xD6
52 #define HI3110_READ_BTR1 0xD8
53 #define HI3110_READ_INTF 0xDE
54 #define HI3110_READ_ERR 0xDC
55 #define HI3110_READ_FIFO_WOTIME 0x48
56 #define HI3110_WRITE_FIFO 0x12
57 #define HI3110_READ_MESSTAT 0xDA
58 #define HI3110_READ_REC 0xEA
59 #define HI3110_READ_TEC 0xEC
60
61 #define HI3110_CTRL0_MODE_MASK (7 << 5)
62 #define HI3110_CTRL0_NORMAL_MODE (0 << 5)
63 #define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
64 #define HI3110_CTRL0_MONITOR_MODE (2 << 5)
65 #define HI3110_CTRL0_SLEEP_MODE (3 << 5)
66 #define HI3110_CTRL0_INIT_MODE (4 << 5)
67
68 #define HI3110_CTRL1_TXEN BIT(7)
69
70 #define HI3110_INT_RXTMP BIT(7)
71 #define HI3110_INT_RXFIFO BIT(6)
72 #define HI3110_INT_TXCPLT BIT(5)
73 #define HI3110_INT_BUSERR BIT(4)
74 #define HI3110_INT_MCHG BIT(3)
75 #define HI3110_INT_WAKEUP BIT(2)
76 #define HI3110_INT_F1MESS BIT(1)
77 #define HI3110_INT_F0MESS BIT(0)
78
79 #define HI3110_ERR_BUSOFF BIT(7)
80 #define HI3110_ERR_TXERRP BIT(6)
81 #define HI3110_ERR_RXERRP BIT(5)
82 #define HI3110_ERR_BITERR BIT(4)
83 #define HI3110_ERR_FRMERR BIT(3)
84 #define HI3110_ERR_CRCERR BIT(2)
85 #define HI3110_ERR_ACKERR BIT(1)
86 #define HI3110_ERR_STUFERR BIT(0)
87 #define HI3110_ERR_PROTOCOL_MASK (0x1F)
88 #define HI3110_ERR_PASSIVE_MASK (0x60)
89
90 #define HI3110_STAT_RXFMTY BIT(1)
91 #define HI3110_STAT_BUSOFF BIT(2)
92 #define HI3110_STAT_ERRP BIT(3)
93 #define HI3110_STAT_ERRW BIT(4)
94 #define HI3110_STAT_TXMTY BIT(7)
95
96 #define HI3110_BTR0_SJW_SHIFT 6
97 #define HI3110_BTR0_BRP_SHIFT 0
98
99 #define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
100 #define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
101 #define HI3110_BTR1_TSEG2_SHIFT 4
102 #define HI3110_BTR1_TSEG1_SHIFT 0
103
104 #define HI3110_FIFO_WOTIME_TAG_OFF 0
105 #define HI3110_FIFO_WOTIME_ID_OFF 1
106 #define HI3110_FIFO_WOTIME_DLC_OFF 5
107 #define HI3110_FIFO_WOTIME_DAT_OFF 6
108
109 #define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
110 #define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
111
112 #define HI3110_FIFO_TAG_OFF 0
113 #define HI3110_FIFO_ID_OFF 1
114 #define HI3110_FIFO_STD_DLC_OFF 3
115 #define HI3110_FIFO_STD_DATA_OFF 4
116 #define HI3110_FIFO_EXT_DLC_OFF 5
117 #define HI3110_FIFO_EXT_DATA_OFF 6
118
119 #define HI3110_CAN_MAX_DATA_LEN 8
120 #define HI3110_RX_BUF_LEN 15
121 #define HI3110_TX_STD_BUF_LEN 12
122 #define HI3110_TX_EXT_BUF_LEN 14
123 #define HI3110_CAN_FRAME_MAX_BITS 128
124 #define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
125
126 #define HI3110_TX_ECHO_SKB_MAX 1
127
128 #define HI3110_OST_DELAY_MS (10)
129
130 #define DEVICE_NAME "hi3110"
131
132 static int hi3110_enable_dma = 1; /* Enable SPI DMA. Default: 1 (On) */
133 module_param(hi3110_enable_dma, int, 0444);
134 MODULE_PARM_DESC(hi3110_enable_dma, "Enable SPI DMA. Default: 1 (On)");
135
136 static const struct can_bittiming_const hi3110_bittiming_const = {
137 .name = DEVICE_NAME,
138 .tseg1_min = 2,
139 .tseg1_max = 16,
140 .tseg2_min = 2,
141 .tseg2_max = 8,
142 .sjw_max = 4,
143 .brp_min = 1,
144 .brp_max = 64,
145 .brp_inc = 1,
146 };
147
148 enum hi3110_model {
149 CAN_HI3110_HI3110 = 0x3110,
150 };
151
152 struct hi3110_priv {
153 struct can_priv can;
154 struct net_device *net;
155 struct spi_device *spi;
156 enum hi3110_model model;
157
158 struct mutex hi3110_lock; /* SPI device lock */
159
160 u8 *spi_tx_buf;
161 u8 *spi_rx_buf;
162 dma_addr_t spi_tx_dma;
163 dma_addr_t spi_rx_dma;
164
165 struct sk_buff *tx_skb;
166 int tx_len;
167
168 struct workqueue_struct *wq;
169 struct work_struct tx_work;
170 struct work_struct restart_work;
171
172 int force_quit;
173 int after_suspend;
174 #define HI3110_AFTER_SUSPEND_UP 1
175 #define HI3110_AFTER_SUSPEND_DOWN 2
176 #define HI3110_AFTER_SUSPEND_POWER 4
177 #define HI3110_AFTER_SUSPEND_RESTART 8
178 int restart_tx;
179 struct regulator *power;
180 struct regulator *transceiver;
181 struct clk *clk;
182 };
183
184 static void hi3110_clean(struct net_device *net)
185 {
186 struct hi3110_priv *priv = netdev_priv(net);
187
188 if (priv->tx_skb || priv->tx_len)
189 net->stats.tx_errors++;
190 if (priv->tx_skb)
191 dev_kfree_skb(priv->tx_skb);
192 if (priv->tx_len)
193 can_free_echo_skb(priv->net, 0);
194 priv->tx_skb = NULL;
195 priv->tx_len = 0;
196 }
197
198 /* Note about handling of error return of hi3110_spi_trans: accessing
199 * registers via SPI is not really different conceptually than using
200 * normal I/O assembler instructions, although it's much more
201 * complicated from a practical POV. So it's not advisable to always
202 * check the return value of this function. Imagine that every
203 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
204 * error();", it would be a great mess (well there are some situation
205 * when exception handling C++ like could be useful after all). So we
206 * just check that transfers are OK at the beginning of our
207 * conversation with the chip and to avoid doing really nasty things
208 * (like injecting bogus packets in the network stack).
209 */
210 static int hi3110_spi_trans(struct spi_device *spi, int len)
211 {
212 struct hi3110_priv *priv = spi_get_drvdata(spi);
213 struct spi_transfer t = {
214 .tx_buf = priv->spi_tx_buf,
215 .rx_buf = priv->spi_rx_buf,
216 .len = len,
217 .cs_change = 0,
218 };
219 struct spi_message m;
220 int ret;
221
222 spi_message_init(&m);
223
224 if (hi3110_enable_dma) {
225 t.tx_dma = priv->spi_tx_dma;
226 t.rx_dma = priv->spi_rx_dma;
227 m.is_dma_mapped = 1;
228 }
229
230 spi_message_add_tail(&t, &m);
231
232 ret = spi_sync(spi, &m);
233
234 if (ret)
235 dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
236 return ret;
237 }
238
239 static u8 hi3110_cmd(struct spi_device *spi, u8 command)
240 {
241 struct hi3110_priv *priv = spi_get_drvdata(spi);
242
243 priv->spi_tx_buf[0] = command;
244 dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
245
246 return hi3110_spi_trans(spi, 1);
247 }
248
249 static u8 hi3110_read(struct spi_device *spi, u8 command)
250 {
251 struct hi3110_priv *priv = spi_get_drvdata(spi);
252 u8 val = 0;
253
254 priv->spi_tx_buf[0] = command;
255 hi3110_spi_trans(spi, 2);
256 val = priv->spi_rx_buf[1];
257
258 return val;
259 }
260
261 static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
262 {
263 struct hi3110_priv *priv = spi_get_drvdata(spi);
264
265 priv->spi_tx_buf[0] = reg;
266 priv->spi_tx_buf[1] = val;
267 hi3110_spi_trans(spi, 2);
268 }
269
270 static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
271 {
272 struct hi3110_priv *priv = spi_get_drvdata(spi);
273
274 priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
275 memcpy(priv->spi_tx_buf + 1, buf, len);
276 hi3110_spi_trans(spi, len + 1);
277 }
278
279 static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
280 {
281 u8 buf[HI3110_TX_EXT_BUF_LEN];
282
283 buf[HI3110_FIFO_TAG_OFF] = 0;
284
285 if (frame->can_id & CAN_EFF_FLAG) {
286 /* Extended frame */
287 buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
288 buf[HI3110_FIFO_ID_OFF + 1] =
289 (((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
290 HI3110_EFF_FLAGS |
291 (((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
292 buf[HI3110_FIFO_ID_OFF + 2] =
293 (frame->can_id & CAN_EFF_MASK) >> 7;
294 buf[HI3110_FIFO_ID_OFF + 3] =
295 ((frame->can_id & CAN_EFF_MASK) << 1) |
296 ((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
297
298 buf[HI3110_FIFO_EXT_DLC_OFF] = frame->can_dlc;
299
300 memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
301 frame->data, frame->can_dlc);
302
303 hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
304 (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
305 } else {
306 /* Standard frame */
307 buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_SFF_MASK) >> 3;
308 buf[HI3110_FIFO_ID_OFF + 1] =
309 ((frame->can_id & CAN_SFF_MASK) << 5) |
310 ((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
311
312 buf[HI3110_FIFO_STD_DLC_OFF] = frame->can_dlc;
313
314 memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
315 frame->data, frame->can_dlc);
316
317 hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
318 (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
319 }
320 }
321
322 static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
323 {
324 struct hi3110_priv *priv = spi_get_drvdata(spi);
325
326 priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
327 hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
328 memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
329 }
330
331 static void hi3110_hw_rx(struct spi_device *spi)
332 {
333 struct hi3110_priv *priv = spi_get_drvdata(spi);
334 struct sk_buff *skb;
335 struct can_frame *frame;
336 u8 buf[HI3110_RX_BUF_LEN - 1];
337
338 skb = alloc_can_skb(priv->net, &frame);
339 if (!skb) {
340 priv->net->stats.rx_dropped++;
341 return;
342 }
343
344 hi3110_hw_rx_frame(spi, buf);
345 if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
346 /* IDE is recessive (1), indicating extended 29-bit frame */
347 frame->can_id = CAN_EFF_FLAG;
348 frame->can_id |=
349 (buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
350 (((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
351 ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
352 (buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
353 (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
354 } else {
355 /* IDE is dominant (0), frame indicating standard 11-bit */
356 frame->can_id =
357 (buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
358 ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
359 }
360
361 /* Data length */
362 frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
363
364 if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
365 frame->can_id |= CAN_RTR_FLAG;
366 else
367 memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
368 frame->can_dlc);
369
370 priv->net->stats.rx_packets++;
371 priv->net->stats.rx_bytes += frame->can_dlc;
372
373 can_led_event(priv->net, CAN_LED_EVENT_RX);
374
375 netif_rx_ni(skb);
376 }
377
378 static void hi3110_hw_sleep(struct spi_device *spi)
379 {
380 hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
381 }
382
383 static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
384 struct net_device *net)
385 {
386 struct hi3110_priv *priv = netdev_priv(net);
387 struct spi_device *spi = priv->spi;
388
389 if (priv->tx_skb || priv->tx_len) {
390 dev_err(&spi->dev, "hard_xmit called while tx busy\n");
391 return NETDEV_TX_BUSY;
392 }
393
394 if (can_dropped_invalid_skb(net, skb))
395 return NETDEV_TX_OK;
396
397 netif_stop_queue(net);
398 priv->tx_skb = skb;
399 queue_work(priv->wq, &priv->tx_work);
400
401 return NETDEV_TX_OK;
402 }
403
404 static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
405 {
406 struct hi3110_priv *priv = netdev_priv(net);
407
408 switch (mode) {
409 case CAN_MODE_START:
410 hi3110_clean(net);
411 /* We have to delay work since SPI I/O may sleep */
412 priv->can.state = CAN_STATE_ERROR_ACTIVE;
413 priv->restart_tx = 1;
414 if (priv->can.restart_ms == 0)
415 priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
416 queue_work(priv->wq, &priv->restart_work);
417 break;
418 default:
419 return -EOPNOTSUPP;
420 }
421
422 return 0;
423 }
424
425 static int hi3110_get_berr_counter(const struct net_device *net,
426 struct can_berr_counter *bec)
427 {
428 struct hi3110_priv *priv = netdev_priv(net);
429 struct spi_device *spi = priv->spi;
430
431 mutex_lock(&priv->hi3110_lock);
432 bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
433 bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
434 mutex_unlock(&priv->hi3110_lock);
435
436 return 0;
437 }
438
439 static int hi3110_set_normal_mode(struct spi_device *spi)
440 {
441 struct hi3110_priv *priv = spi_get_drvdata(spi);
442 u8 reg = 0;
443
444 hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
445 HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
446
447 /* Enable TX */
448 hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
449
450 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
451 reg = HI3110_CTRL0_LOOPBACK_MODE;
452 else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
453 reg = HI3110_CTRL0_MONITOR_MODE;
454 else
455 reg = HI3110_CTRL0_NORMAL_MODE;
456
457 hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
458
459 /* Wait for the device to enter the mode */
460 mdelay(HI3110_OST_DELAY_MS);
461 reg = hi3110_read(spi, HI3110_READ_CTRL0);
462 if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
463 return -EBUSY;
464
465 priv->can.state = CAN_STATE_ERROR_ACTIVE;
466 return 0;
467 }
468
469 static int hi3110_do_set_bittiming(struct net_device *net)
470 {
471 struct hi3110_priv *priv = netdev_priv(net);
472 struct can_bittiming *bt = &priv->can.bittiming;
473 struct spi_device *spi = priv->spi;
474
475 hi3110_write(spi, HI3110_WRITE_BTR0,
476 ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
477 ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
478
479 hi3110_write(spi, HI3110_WRITE_BTR1,
480 (priv->can.ctrlmode &
481 CAN_CTRLMODE_3_SAMPLES ?
482 HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
483 ((bt->phase_seg1 + bt->prop_seg - 1)
484 << HI3110_BTR1_TSEG1_SHIFT) |
485 ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
486
487 dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
488 hi3110_read(spi, HI3110_READ_BTR0),
489 hi3110_read(spi, HI3110_READ_BTR1));
490
491 return 0;
492 }
493
494 static int hi3110_setup(struct net_device *net)
495 {
496 hi3110_do_set_bittiming(net);
497 return 0;
498 }
499
500 static int hi3110_hw_reset(struct spi_device *spi)
501 {
502 u8 reg;
503 int ret;
504
505 /* Wait for oscillator startup timer after power up */
506 mdelay(HI3110_OST_DELAY_MS);
507
508 ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
509 if (ret)
510 return ret;
511
512 /* Wait for oscillator startup timer after reset */
513 mdelay(HI3110_OST_DELAY_MS);
514
515 reg = hi3110_read(spi, HI3110_READ_CTRL0);
516 if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
517 return -ENODEV;
518
519 /* As per the datasheet it appears the error flags are
520 * not cleared on reset. Explicitly clear them by performing a read
521 */
522 hi3110_read(spi, HI3110_READ_ERR);
523
524 return 0;
525 }
526
527 static int hi3110_hw_probe(struct spi_device *spi)
528 {
529 u8 statf;
530
531 hi3110_hw_reset(spi);
532
533 /* Confirm correct operation by checking against reset values
534 * in datasheet
535 */
536 statf = hi3110_read(spi, HI3110_READ_STATF);
537
538 dev_dbg(&spi->dev, "statf: %02X\n", statf);
539
540 if (statf != 0x82)
541 return -ENODEV;
542
543 return 0;
544 }
545
546 static int hi3110_power_enable(struct regulator *reg, int enable)
547 {
548 if (IS_ERR_OR_NULL(reg))
549 return 0;
550
551 if (enable)
552 return regulator_enable(reg);
553 else
554 return regulator_disable(reg);
555 }
556
557 static int hi3110_stop(struct net_device *net)
558 {
559 struct hi3110_priv *priv = netdev_priv(net);
560 struct spi_device *spi = priv->spi;
561
562 close_candev(net);
563
564 priv->force_quit = 1;
565 free_irq(spi->irq, priv);
566 destroy_workqueue(priv->wq);
567 priv->wq = NULL;
568
569 mutex_lock(&priv->hi3110_lock);
570
571 /* Disable transmit, interrupts and clear flags */
572 hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
573 hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
574 hi3110_read(spi, HI3110_READ_INTF);
575
576 hi3110_clean(net);
577
578 hi3110_hw_sleep(spi);
579
580 hi3110_power_enable(priv->transceiver, 0);
581
582 priv->can.state = CAN_STATE_STOPPED;
583
584 mutex_unlock(&priv->hi3110_lock);
585
586 can_led_event(net, CAN_LED_EVENT_STOP);
587
588 return 0;
589 }
590
591 static void hi3110_tx_work_handler(struct work_struct *ws)
592 {
593 struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
594 tx_work);
595 struct spi_device *spi = priv->spi;
596 struct net_device *net = priv->net;
597 struct can_frame *frame;
598
599 mutex_lock(&priv->hi3110_lock);
600 if (priv->tx_skb) {
601 if (priv->can.state == CAN_STATE_BUS_OFF) {
602 hi3110_clean(net);
603 } else {
604 frame = (struct can_frame *)priv->tx_skb->data;
605 hi3110_hw_tx(spi, frame);
606 priv->tx_len = 1 + frame->can_dlc;
607 can_put_echo_skb(priv->tx_skb, net, 0);
608 priv->tx_skb = NULL;
609 }
610 }
611 mutex_unlock(&priv->hi3110_lock);
612 }
613
614 static void hi3110_restart_work_handler(struct work_struct *ws)
615 {
616 struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
617 restart_work);
618 struct spi_device *spi = priv->spi;
619 struct net_device *net = priv->net;
620
621 mutex_lock(&priv->hi3110_lock);
622 if (priv->after_suspend) {
623 hi3110_hw_reset(spi);
624 hi3110_setup(net);
625 if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
626 hi3110_set_normal_mode(spi);
627 } else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
628 netif_device_attach(net);
629 hi3110_clean(net);
630 hi3110_set_normal_mode(spi);
631 netif_wake_queue(net);
632 } else {
633 hi3110_hw_sleep(spi);
634 }
635 priv->after_suspend = 0;
636 priv->force_quit = 0;
637 }
638
639 if (priv->restart_tx) {
640 priv->restart_tx = 0;
641 hi3110_hw_reset(spi);
642 hi3110_setup(net);
643 hi3110_clean(net);
644 hi3110_set_normal_mode(spi);
645 netif_wake_queue(net);
646 }
647 mutex_unlock(&priv->hi3110_lock);
648 }
649
650 static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
651 {
652 struct hi3110_priv *priv = dev_id;
653 struct spi_device *spi = priv->spi;
654 struct net_device *net = priv->net;
655
656 mutex_lock(&priv->hi3110_lock);
657
658 while (!priv->force_quit) {
659 enum can_state new_state;
660 u8 intf, eflag, statf;
661
662 while (!(HI3110_STAT_RXFMTY &
663 (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
664 hi3110_hw_rx(spi);
665 }
666
667 intf = hi3110_read(spi, HI3110_READ_INTF);
668 eflag = hi3110_read(spi, HI3110_READ_ERR);
669 /* Update can state */
670 if (eflag & HI3110_ERR_BUSOFF)
671 new_state = CAN_STATE_BUS_OFF;
672 else if (eflag & HI3110_ERR_PASSIVE_MASK)
673 new_state = CAN_STATE_ERROR_PASSIVE;
674 else if (statf & HI3110_STAT_ERRW)
675 new_state = CAN_STATE_ERROR_WARNING;
676 else
677 new_state = CAN_STATE_ERROR_ACTIVE;
678
679 if (new_state != priv->can.state) {
680 struct can_frame *cf;
681 struct sk_buff *skb;
682 enum can_state rx_state, tx_state;
683 u8 rxerr, txerr;
684
685 skb = alloc_can_err_skb(net, &cf);
686 if (!skb)
687 break;
688
689 txerr = hi3110_read(spi, HI3110_READ_TEC);
690 rxerr = hi3110_read(spi, HI3110_READ_REC);
691 cf->data[6] = txerr;
692 cf->data[7] = rxerr;
693 tx_state = txerr >= rxerr ? new_state : 0;
694 rx_state = txerr <= rxerr ? new_state : 0;
695 can_change_state(net, cf, tx_state, rx_state);
696 netif_rx_ni(skb);
697
698 if (new_state == CAN_STATE_BUS_OFF) {
699 can_bus_off(net);
700 if (priv->can.restart_ms == 0) {
701 priv->force_quit = 1;
702 hi3110_hw_sleep(spi);
703 break;
704 }
705 }
706 }
707
708 /* Update bus errors */
709 if ((intf & HI3110_INT_BUSERR) &&
710 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
711 struct can_frame *cf;
712 struct sk_buff *skb;
713
714 /* Check for protocol errors */
715 if (eflag & HI3110_ERR_PROTOCOL_MASK) {
716 skb = alloc_can_err_skb(net, &cf);
717 if (!skb)
718 break;
719
720 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
721 priv->can.can_stats.bus_error++;
722 priv->net->stats.rx_errors++;
723 if (eflag & HI3110_ERR_BITERR)
724 cf->data[2] |= CAN_ERR_PROT_BIT;
725 else if (eflag & HI3110_ERR_FRMERR)
726 cf->data[2] |= CAN_ERR_PROT_FORM;
727 else if (eflag & HI3110_ERR_STUFERR)
728 cf->data[2] |= CAN_ERR_PROT_STUFF;
729 else if (eflag & HI3110_ERR_CRCERR)
730 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
731 else if (eflag & HI3110_ERR_ACKERR)
732 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
733
734 cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
735 cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
736 netdev_dbg(priv->net, "Bus Error\n");
737 netif_rx_ni(skb);
738 }
739 }
740
741 if (priv->tx_len && statf & HI3110_STAT_TXMTY) {
742 net->stats.tx_packets++;
743 net->stats.tx_bytes += priv->tx_len - 1;
744 can_led_event(net, CAN_LED_EVENT_TX);
745 if (priv->tx_len) {
746 can_get_echo_skb(net, 0);
747 priv->tx_len = 0;
748 }
749 netif_wake_queue(net);
750 }
751
752 if (intf == 0)
753 break;
754 }
755 mutex_unlock(&priv->hi3110_lock);
756 return IRQ_HANDLED;
757 }
758
759 static int hi3110_open(struct net_device *net)
760 {
761 struct hi3110_priv *priv = netdev_priv(net);
762 struct spi_device *spi = priv->spi;
763 unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_HIGH;
764 int ret;
765
766 ret = open_candev(net);
767 if (ret)
768 return ret;
769
770 mutex_lock(&priv->hi3110_lock);
771 hi3110_power_enable(priv->transceiver, 1);
772
773 priv->force_quit = 0;
774 priv->tx_skb = NULL;
775 priv->tx_len = 0;
776
777 ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
778 flags, DEVICE_NAME, priv);
779 if (ret) {
780 dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
781 goto out_close;
782 }
783
784 priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
785 0);
786 if (!priv->wq) {
787 ret = -ENOMEM;
788 goto out_free_irq;
789 }
790 INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
791 INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
792
793 ret = hi3110_hw_reset(spi);
794 if (ret)
795 goto out_free_wq;
796
797 ret = hi3110_setup(net);
798 if (ret)
799 goto out_free_wq;
800
801 ret = hi3110_set_normal_mode(spi);
802 if (ret)
803 goto out_free_wq;
804
805 can_led_event(net, CAN_LED_EVENT_OPEN);
806 netif_wake_queue(net);
807 mutex_unlock(&priv->hi3110_lock);
808
809 return 0;
810
811 out_free_wq:
812 destroy_workqueue(priv->wq);
813 out_free_irq:
814 free_irq(spi->irq, priv);
815 hi3110_hw_sleep(spi);
816 out_close:
817 hi3110_power_enable(priv->transceiver, 0);
818 close_candev(net);
819 mutex_unlock(&priv->hi3110_lock);
820 return ret;
821 }
822
823 static const struct net_device_ops hi3110_netdev_ops = {
824 .ndo_open = hi3110_open,
825 .ndo_stop = hi3110_stop,
826 .ndo_start_xmit = hi3110_hard_start_xmit,
827 };
828
829 static const struct of_device_id hi3110_of_match[] = {
830 {
831 .compatible = "holt,hi3110",
832 .data = (void *)CAN_HI3110_HI3110,
833 },
834 { }
835 };
836 MODULE_DEVICE_TABLE(of, hi3110_of_match);
837
838 static const struct spi_device_id hi3110_id_table[] = {
839 {
840 .name = "hi3110",
841 .driver_data = (kernel_ulong_t)CAN_HI3110_HI3110,
842 },
843 { }
844 };
845 MODULE_DEVICE_TABLE(spi, hi3110_id_table);
846
847 static int hi3110_can_probe(struct spi_device *spi)
848 {
849 const struct of_device_id *of_id = of_match_device(hi3110_of_match,
850 &spi->dev);
851 struct net_device *net;
852 struct hi3110_priv *priv;
853 struct clk *clk;
854 int freq, ret;
855
856 clk = devm_clk_get(&spi->dev, NULL);
857 if (IS_ERR(clk)) {
858 dev_err(&spi->dev, "no CAN clock source defined\n");
859 return PTR_ERR(clk);
860 }
861 freq = clk_get_rate(clk);
862
863 /* Sanity check */
864 if (freq > 40000000)
865 return -ERANGE;
866
867 /* Allocate can/net device */
868 net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
869 if (!net)
870 return -ENOMEM;
871
872 if (!IS_ERR(clk)) {
873 ret = clk_prepare_enable(clk);
874 if (ret)
875 goto out_free;
876 }
877
878 net->netdev_ops = &hi3110_netdev_ops;
879 net->flags |= IFF_ECHO;
880
881 priv = netdev_priv(net);
882 priv->can.bittiming_const = &hi3110_bittiming_const;
883 priv->can.do_set_mode = hi3110_do_set_mode;
884 priv->can.do_get_berr_counter = hi3110_get_berr_counter;
885 priv->can.clock.freq = freq / 2;
886 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
887 CAN_CTRLMODE_LOOPBACK |
888 CAN_CTRLMODE_LISTENONLY |
889 CAN_CTRLMODE_BERR_REPORTING;
890
891 if (of_id)
892 priv->model = (enum hi3110_model)of_id->data;
893 else
894 priv->model = spi_get_device_id(spi)->driver_data;
895 priv->net = net;
896 priv->clk = clk;
897
898 spi_set_drvdata(spi, priv);
899
900 /* Configure the SPI bus */
901 spi->bits_per_word = 8;
902 ret = spi_setup(spi);
903 if (ret)
904 goto out_clk;
905
906 priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
907 priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
908 if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
909 (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
910 ret = -EPROBE_DEFER;
911 goto out_clk;
912 }
913
914 ret = hi3110_power_enable(priv->power, 1);
915 if (ret)
916 goto out_clk;
917
918 priv->spi = spi;
919 mutex_init(&priv->hi3110_lock);
920
921 /* If requested, allocate DMA buffers */
922 if (hi3110_enable_dma) {
923 spi->dev.coherent_dma_mask = ~0;
924
925 /* Minimum coherent DMA allocation is PAGE_SIZE, so allocate
926 * that much and share it between Tx and Rx DMA buffers.
927 */
928 priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
929 PAGE_SIZE,
930 &priv->spi_tx_dma,
931 GFP_DMA);
932
933 if (priv->spi_tx_buf) {
934 priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
935 priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
936 (PAGE_SIZE / 2));
937 } else {
938 /* Fall back to non-DMA */
939 hi3110_enable_dma = 0;
940 }
941 }
942
943 /* Allocate non-DMA buffers */
944 if (!hi3110_enable_dma) {
945 priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
946 GFP_KERNEL);
947 if (!priv->spi_tx_buf) {
948 ret = -ENOMEM;
949 goto error_probe;
950 }
951 priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
952 GFP_KERNEL);
953
954 if (!priv->spi_rx_buf) {
955 ret = -ENOMEM;
956 goto error_probe;
957 }
958 }
959
960 SET_NETDEV_DEV(net, &spi->dev);
961
962 ret = hi3110_hw_probe(spi);
963 if (ret) {
964 if (ret == -ENODEV)
965 dev_err(&spi->dev, "Cannot initialize %x. Wrong wiring?\n",
966 priv->model);
967 goto error_probe;
968 }
969 hi3110_hw_sleep(spi);
970
971 ret = register_candev(net);
972 if (ret)
973 goto error_probe;
974
975 devm_can_led_init(net);
976 netdev_info(net, "%x successfully initialized.\n", priv->model);
977
978 return 0;
979
980 error_probe:
981 hi3110_power_enable(priv->power, 0);
982
983 out_clk:
984 if (!IS_ERR(clk))
985 clk_disable_unprepare(clk);
986
987 out_free:
988 free_candev(net);
989
990 dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
991 return ret;
992 }
993
994 static int hi3110_can_remove(struct spi_device *spi)
995 {
996 struct hi3110_priv *priv = spi_get_drvdata(spi);
997 struct net_device *net = priv->net;
998
999 unregister_candev(net);
1000
1001 hi3110_power_enable(priv->power, 0);
1002
1003 if (!IS_ERR(priv->clk))
1004 clk_disable_unprepare(priv->clk);
1005
1006 free_candev(net);
1007
1008 return 0;
1009 }
1010
1011 static int __maybe_unused hi3110_can_suspend(struct device *dev)
1012 {
1013 struct spi_device *spi = to_spi_device(dev);
1014 struct hi3110_priv *priv = spi_get_drvdata(spi);
1015 struct net_device *net = priv->net;
1016
1017 priv->force_quit = 1;
1018 disable_irq(spi->irq);
1019
1020 /* Note: at this point neither IST nor workqueues are running.
1021 * open/stop cannot be called anyway so locking is not needed
1022 */
1023 if (netif_running(net)) {
1024 netif_device_detach(net);
1025
1026 hi3110_hw_sleep(spi);
1027 hi3110_power_enable(priv->transceiver, 0);
1028 priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
1029 } else {
1030 priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
1031 }
1032
1033 if (!IS_ERR_OR_NULL(priv->power)) {
1034 regulator_disable(priv->power);
1035 priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
1036 }
1037
1038 return 0;
1039 }
1040
1041 static int __maybe_unused hi3110_can_resume(struct device *dev)
1042 {
1043 struct spi_device *spi = to_spi_device(dev);
1044 struct hi3110_priv *priv = spi_get_drvdata(spi);
1045
1046 if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
1047 hi3110_power_enable(priv->power, 1);
1048
1049 if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
1050 hi3110_power_enable(priv->transceiver, 1);
1051 queue_work(priv->wq, &priv->restart_work);
1052 } else {
1053 priv->after_suspend = 0;
1054 }
1055
1056 priv->force_quit = 0;
1057 enable_irq(spi->irq);
1058 return 0;
1059 }
1060
1061 static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);
1062
1063 static struct spi_driver hi3110_can_driver = {
1064 .driver = {
1065 .name = DEVICE_NAME,
1066 .of_match_table = hi3110_of_match,
1067 .pm = &hi3110_can_pm_ops,
1068 },
1069 .id_table = hi3110_id_table,
1070 .probe = hi3110_can_probe,
1071 .remove = hi3110_can_remove,
1072 };
1073
1074 module_spi_driver(hi3110_can_driver);
1075
1076 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
1077 MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
1078 MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
1079 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support