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David S. Miller99c4a632009-09-25 12:14:43 -07001/*
2 * at91_can.c - CAN network driver for AT91 SoC CAN controller
3 *
Hans J. Koch3e9ebd32010-10-29 12:33:57 +00004 * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
Marc Kleine-Budde0909c1e2011-01-06 09:58:42 +01005 * (C) 2008, 2009, 2010, 2011 by Marc Kleine-Budde <kernel@pengutronix.de>
David S. Miller99c4a632009-09-25 12:14:43 -07006 *
7 * This software may be distributed under the terms of the GNU General
8 * Public License ("GPL") version 2 as distributed in the 'COPYING'
9 * file from the main directory of the linux kernel source.
10 *
David S. Miller99c4a632009-09-25 12:14:43 -070011 *
12 * Your platform definition file should specify something like:
13 *
14 * static struct at91_can_data ek_can_data = {
15 * transceiver_switch = sam9263ek_transceiver_switch,
16 * };
17 *
18 * at91_add_device_can(&ek_can_data);
19 *
20 */
21
22#include <linux/clk.h>
23#include <linux/errno.h>
24#include <linux/if_arp.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/netdevice.h>
30#include <linux/platform_device.h>
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +010031#include <linux/rtnetlink.h>
David S. Miller99c4a632009-09-25 12:14:43 -070032#include <linux/skbuff.h>
33#include <linux/spinlock.h>
34#include <linux/string.h>
35#include <linux/types.h>
Jean-Christophe PLAGNIOL-VILLARDbcd23602012-10-30 05:12:23 +080036#include <linux/platform_data/atmel.h>
David S. Miller99c4a632009-09-25 12:14:43 -070037
David S. Miller99c4a632009-09-25 12:14:43 -070038#include <linux/can/dev.h>
39#include <linux/can/error.h>
Fabio Baltieri4723f2b2012-12-18 18:50:59 +010040#include <linux/can/led.h>
David S. Miller99c4a632009-09-25 12:14:43 -070041
Marc Kleine-Buddeb0499942011-05-03 16:37:16 +020042#define AT91_MB_MASK(i) ((1 << (i)) - 1)
David S. Miller99c4a632009-09-25 12:14:43 -070043
44/* Common registers */
45enum at91_reg {
46 AT91_MR = 0x000,
47 AT91_IER = 0x004,
48 AT91_IDR = 0x008,
49 AT91_IMR = 0x00C,
50 AT91_SR = 0x010,
51 AT91_BR = 0x014,
52 AT91_TIM = 0x018,
53 AT91_TIMESTP = 0x01C,
54 AT91_ECR = 0x020,
55 AT91_TCR = 0x024,
56 AT91_ACR = 0x028,
57};
58
59/* Mailbox registers (0 <= i <= 15) */
60#define AT91_MMR(i) (enum at91_reg)(0x200 + ((i) * 0x20))
61#define AT91_MAM(i) (enum at91_reg)(0x204 + ((i) * 0x20))
62#define AT91_MID(i) (enum at91_reg)(0x208 + ((i) * 0x20))
63#define AT91_MFID(i) (enum at91_reg)(0x20C + ((i) * 0x20))
64#define AT91_MSR(i) (enum at91_reg)(0x210 + ((i) * 0x20))
65#define AT91_MDL(i) (enum at91_reg)(0x214 + ((i) * 0x20))
66#define AT91_MDH(i) (enum at91_reg)(0x218 + ((i) * 0x20))
67#define AT91_MCR(i) (enum at91_reg)(0x21C + ((i) * 0x20))
68
69/* Register bits */
70#define AT91_MR_CANEN BIT(0)
71#define AT91_MR_LPM BIT(1)
72#define AT91_MR_ABM BIT(2)
73#define AT91_MR_OVL BIT(3)
74#define AT91_MR_TEOF BIT(4)
75#define AT91_MR_TTM BIT(5)
76#define AT91_MR_TIMFRZ BIT(6)
77#define AT91_MR_DRPT BIT(7)
78
79#define AT91_SR_RBSY BIT(29)
80
81#define AT91_MMR_PRIO_SHIFT (16)
82
83#define AT91_MID_MIDE BIT(29)
84
85#define AT91_MSR_MRTR BIT(20)
86#define AT91_MSR_MABT BIT(22)
87#define AT91_MSR_MRDY BIT(23)
88#define AT91_MSR_MMI BIT(24)
89
90#define AT91_MCR_MRTR BIT(20)
91#define AT91_MCR_MTCR BIT(23)
92
93/* Mailbox Modes */
94enum at91_mb_mode {
95 AT91_MB_MODE_DISABLED = 0,
96 AT91_MB_MODE_RX = 1,
97 AT91_MB_MODE_RX_OVRWR = 2,
98 AT91_MB_MODE_TX = 3,
99 AT91_MB_MODE_CONSUMER = 4,
100 AT91_MB_MODE_PRODUCER = 5,
101};
102
103/* Interrupt mask bits */
David S. Miller99c4a632009-09-25 12:14:43 -0700104#define AT91_IRQ_ERRA (1 << 16)
105#define AT91_IRQ_WARN (1 << 17)
106#define AT91_IRQ_ERRP (1 << 18)
107#define AT91_IRQ_BOFF (1 << 19)
108#define AT91_IRQ_SLEEP (1 << 20)
109#define AT91_IRQ_WAKEUP (1 << 21)
110#define AT91_IRQ_TOVF (1 << 22)
111#define AT91_IRQ_TSTP (1 << 23)
112#define AT91_IRQ_CERR (1 << 24)
113#define AT91_IRQ_SERR (1 << 25)
114#define AT91_IRQ_AERR (1 << 26)
115#define AT91_IRQ_FERR (1 << 27)
116#define AT91_IRQ_BERR (1 << 28)
117
118#define AT91_IRQ_ERR_ALL (0x1fff0000)
119#define AT91_IRQ_ERR_FRAME (AT91_IRQ_CERR | AT91_IRQ_SERR | \
120 AT91_IRQ_AERR | AT91_IRQ_FERR | AT91_IRQ_BERR)
121#define AT91_IRQ_ERR_LINE (AT91_IRQ_ERRA | AT91_IRQ_WARN | \
122 AT91_IRQ_ERRP | AT91_IRQ_BOFF)
123
124#define AT91_IRQ_ALL (0x1fffffff)
125
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200126enum at91_devtype {
127 AT91_DEVTYPE_SAM9263,
Marc Kleine-Budde6388b392011-04-17 00:08:45 +0200128 AT91_DEVTYPE_SAM9X5,
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200129};
130
131struct at91_devtype_data {
132 unsigned int rx_first;
133 unsigned int rx_split;
134 unsigned int rx_last;
135 unsigned int tx_shift;
136 enum at91_devtype type;
137};
138
David S. Miller99c4a632009-09-25 12:14:43 -0700139struct at91_priv {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100140 struct can_priv can; /* must be the first member! */
141 struct net_device *dev;
142 struct napi_struct napi;
David S. Miller99c4a632009-09-25 12:14:43 -0700143
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100144 void __iomem *reg_base;
David S. Miller99c4a632009-09-25 12:14:43 -0700145
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100146 u32 reg_sr;
147 unsigned int tx_next;
148 unsigned int tx_echo;
149 unsigned int rx_next;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200150 struct at91_devtype_data devtype_data;
David S. Miller99c4a632009-09-25 12:14:43 -0700151
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100152 struct clk *clk;
153 struct at91_can_data *pdata;
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100154
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100155 canid_t mb0_id;
David S. Miller99c4a632009-09-25 12:14:43 -0700156};
157
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -0500158static const struct at91_devtype_data at91_devtype_data[] = {
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200159 [AT91_DEVTYPE_SAM9263] = {
160 .rx_first = 1,
161 .rx_split = 8,
162 .rx_last = 11,
163 .tx_shift = 2,
164 },
Marc Kleine-Budde6388b392011-04-17 00:08:45 +0200165 [AT91_DEVTYPE_SAM9X5] = {
166 .rx_first = 0,
167 .rx_split = 4,
168 .rx_last = 5,
169 .tx_shift = 1,
170 },
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200171};
172
Marc Kleine-Budde194b9a42012-07-16 12:58:31 +0200173static const struct can_bittiming_const at91_bittiming_const = {
Marc Kleine-Budde00389b02010-10-21 01:01:22 +0000174 .name = KBUILD_MODNAME,
David S. Miller99c4a632009-09-25 12:14:43 -0700175 .tseg1_min = 4,
176 .tseg1_max = 16,
177 .tseg2_min = 2,
178 .tseg2_max = 8,
179 .sjw_max = 4,
180 .brp_min = 2,
181 .brp_max = 128,
182 .brp_inc = 1,
183};
184
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200185#define AT91_IS(_model) \
186static inline int at91_is_sam##_model(const struct at91_priv *priv) \
187{ \
188 return priv->devtype_data.type == AT91_DEVTYPE_SAM##_model; \
189}
190
191AT91_IS(9263);
Marc Kleine-Budde6388b392011-04-17 00:08:45 +0200192AT91_IS(9X5);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200193
194static inline unsigned int get_mb_rx_first(const struct at91_priv *priv)
195{
196 return priv->devtype_data.rx_first;
197}
198
199static inline unsigned int get_mb_rx_last(const struct at91_priv *priv)
200{
201 return priv->devtype_data.rx_last;
202}
203
204static inline unsigned int get_mb_rx_split(const struct at91_priv *priv)
205{
206 return priv->devtype_data.rx_split;
207}
208
209static inline unsigned int get_mb_rx_num(const struct at91_priv *priv)
210{
211 return get_mb_rx_last(priv) - get_mb_rx_first(priv) + 1;
212}
213
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200214static inline unsigned int get_mb_rx_low_last(const struct at91_priv *priv)
215{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200216 return get_mb_rx_split(priv) - 1;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200217}
218
219static inline unsigned int get_mb_rx_low_mask(const struct at91_priv *priv)
220{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200221 return AT91_MB_MASK(get_mb_rx_split(priv)) &
222 ~AT91_MB_MASK(get_mb_rx_first(priv));
223}
224
225static inline unsigned int get_mb_tx_shift(const struct at91_priv *priv)
226{
227 return priv->devtype_data.tx_shift;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200228}
229
230static inline unsigned int get_mb_tx_num(const struct at91_priv *priv)
231{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200232 return 1 << get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200233}
234
235static inline unsigned int get_mb_tx_first(const struct at91_priv *priv)
236{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200237 return get_mb_rx_last(priv) + 1;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200238}
239
240static inline unsigned int get_mb_tx_last(const struct at91_priv *priv)
241{
242 return get_mb_tx_first(priv) + get_mb_tx_num(priv) - 1;
243}
244
245static inline unsigned int get_next_prio_shift(const struct at91_priv *priv)
246{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200247 return get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200248}
249
250static inline unsigned int get_next_prio_mask(const struct at91_priv *priv)
251{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200252 return 0xf << get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200253}
254
255static inline unsigned int get_next_mb_mask(const struct at91_priv *priv)
256{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200257 return AT91_MB_MASK(get_mb_tx_shift(priv));
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200258}
259
260static inline unsigned int get_next_mask(const struct at91_priv *priv)
261{
262 return get_next_mb_mask(priv) | get_next_prio_mask(priv);
263}
264
265static inline unsigned int get_irq_mb_rx(const struct at91_priv *priv)
266{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200267 return AT91_MB_MASK(get_mb_rx_last(priv) + 1) &
268 ~AT91_MB_MASK(get_mb_rx_first(priv));
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200269}
270
271static inline unsigned int get_irq_mb_tx(const struct at91_priv *priv)
272{
273 return AT91_MB_MASK(get_mb_tx_last(priv) + 1) &
274 ~AT91_MB_MASK(get_mb_tx_first(priv));
275}
276
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200277static inline unsigned int get_tx_next_mb(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700278{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200279 return (priv->tx_next & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700280}
281
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200282static inline unsigned int get_tx_next_prio(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700283{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200284 return (priv->tx_next >> get_next_prio_shift(priv)) & 0xf;
David S. Miller99c4a632009-09-25 12:14:43 -0700285}
286
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200287static inline unsigned int get_tx_echo_mb(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700288{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200289 return (priv->tx_echo & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700290}
291
292static inline u32 at91_read(const struct at91_priv *priv, enum at91_reg reg)
293{
Marc Kleine-Budde7672fe72010-10-21 01:01:20 +0000294 return __raw_readl(priv->reg_base + reg);
David S. Miller99c4a632009-09-25 12:14:43 -0700295}
296
297static inline void at91_write(const struct at91_priv *priv, enum at91_reg reg,
298 u32 value)
299{
Marc Kleine-Budde7672fe72010-10-21 01:01:20 +0000300 __raw_writel(value, priv->reg_base + reg);
David S. Miller99c4a632009-09-25 12:14:43 -0700301}
302
303static inline void set_mb_mode_prio(const struct at91_priv *priv,
304 unsigned int mb, enum at91_mb_mode mode, int prio)
305{
306 at91_write(priv, AT91_MMR(mb), (mode << 24) | (prio << 16));
307}
308
309static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb,
310 enum at91_mb_mode mode)
311{
312 set_mb_mode_prio(priv, mb, mode, 0);
313}
314
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100315static inline u32 at91_can_id_to_reg_mid(canid_t can_id)
316{
317 u32 reg_mid;
318
319 if (can_id & CAN_EFF_FLAG)
320 reg_mid = (can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
321 else
322 reg_mid = (can_id & CAN_SFF_MASK) << 18;
323
324 return reg_mid;
325}
326
David S. Miller99c4a632009-09-25 12:14:43 -0700327/*
328 * Swtich transceiver on or off
329 */
330static void at91_transceiver_switch(const struct at91_priv *priv, int on)
331{
332 if (priv->pdata && priv->pdata->transceiver_switch)
333 priv->pdata->transceiver_switch(on);
334}
335
336static void at91_setup_mailboxes(struct net_device *dev)
337{
338 struct at91_priv *priv = netdev_priv(dev);
339 unsigned int i;
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100340 u32 reg_mid;
David S. Miller99c4a632009-09-25 12:14:43 -0700341
342 /*
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100343 * Due to a chip bug (errata 50.2.6.3 & 50.3.5.3) the first
344 * mailbox is disabled. The next 11 mailboxes are used as a
345 * reception FIFO. The last mailbox is configured with
346 * overwrite option. The overwrite flag indicates a FIFO
347 * overflow.
David S. Miller99c4a632009-09-25 12:14:43 -0700348 */
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100349 reg_mid = at91_can_id_to_reg_mid(priv->mb0_id);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200350 for (i = 0; i < get_mb_rx_first(priv); i++) {
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100351 set_mb_mode(priv, i, AT91_MB_MODE_DISABLED);
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100352 at91_write(priv, AT91_MID(i), reg_mid);
353 at91_write(priv, AT91_MCR(i), 0x0); /* clear dlc */
354 }
355
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200356 for (i = get_mb_rx_first(priv); i < get_mb_rx_last(priv); i++)
David S. Miller99c4a632009-09-25 12:14:43 -0700357 set_mb_mode(priv, i, AT91_MB_MODE_RX);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200358 set_mb_mode(priv, get_mb_rx_last(priv), AT91_MB_MODE_RX_OVRWR);
David S. Miller99c4a632009-09-25 12:14:43 -0700359
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000360 /* reset acceptance mask and id register */
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200361 for (i = get_mb_rx_first(priv); i <= get_mb_rx_last(priv); i++) {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100362 at91_write(priv, AT91_MAM(i), 0x0);
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000363 at91_write(priv, AT91_MID(i), AT91_MID_MIDE);
364 }
365
David S. Miller99c4a632009-09-25 12:14:43 -0700366 /* The last 4 mailboxes are used for transmitting. */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200367 for (i = get_mb_tx_first(priv); i <= get_mb_tx_last(priv); i++)
David S. Miller99c4a632009-09-25 12:14:43 -0700368 set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);
369
370 /* Reset tx and rx helper pointers */
Marc Kleine-Budde0909c1e2011-01-06 09:58:42 +0100371 priv->tx_next = priv->tx_echo = 0;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200372 priv->rx_next = get_mb_rx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700373}
374
375static int at91_set_bittiming(struct net_device *dev)
376{
377 const struct at91_priv *priv = netdev_priv(dev);
378 const struct can_bittiming *bt = &priv->can.bittiming;
379 u32 reg_br;
380
Marc Kleine-Buddedbe91322010-10-21 01:01:13 +0000381 reg_br = ((priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) ? 1 << 24 : 0) |
382 ((bt->brp - 1) << 16) | ((bt->sjw - 1) << 12) |
David S. Miller99c4a632009-09-25 12:14:43 -0700383 ((bt->prop_seg - 1) << 8) | ((bt->phase_seg1 - 1) << 4) |
384 ((bt->phase_seg2 - 1) << 0);
385
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000386 netdev_info(dev, "writing AT91_BR: 0x%08x\n", reg_br);
David S. Miller99c4a632009-09-25 12:14:43 -0700387
388 at91_write(priv, AT91_BR, reg_br);
389
390 return 0;
391}
392
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000393static int at91_get_berr_counter(const struct net_device *dev,
394 struct can_berr_counter *bec)
395{
396 const struct at91_priv *priv = netdev_priv(dev);
397 u32 reg_ecr = at91_read(priv, AT91_ECR);
398
399 bec->rxerr = reg_ecr & 0xff;
400 bec->txerr = reg_ecr >> 16;
401
402 return 0;
403}
404
David S. Miller99c4a632009-09-25 12:14:43 -0700405static void at91_chip_start(struct net_device *dev)
406{
407 struct at91_priv *priv = netdev_priv(dev);
408 u32 reg_mr, reg_ier;
409
410 /* disable interrupts */
411 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
412
413 /* disable chip */
414 reg_mr = at91_read(priv, AT91_MR);
415 at91_write(priv, AT91_MR, reg_mr & ~AT91_MR_CANEN);
416
Marc Kleine-Buddeb156fd02010-10-21 01:01:19 +0000417 at91_set_bittiming(dev);
David S. Miller99c4a632009-09-25 12:14:43 -0700418 at91_setup_mailboxes(dev);
419 at91_transceiver_switch(priv, 1);
420
421 /* enable chip */
422 at91_write(priv, AT91_MR, AT91_MR_CANEN);
423
424 priv->can.state = CAN_STATE_ERROR_ACTIVE;
425
426 /* Enable interrupts */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200427 reg_ier = get_irq_mb_rx(priv) | AT91_IRQ_ERRP | AT91_IRQ_ERR_FRAME;
David S. Miller99c4a632009-09-25 12:14:43 -0700428 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
429 at91_write(priv, AT91_IER, reg_ier);
430}
431
432static void at91_chip_stop(struct net_device *dev, enum can_state state)
433{
434 struct at91_priv *priv = netdev_priv(dev);
435 u32 reg_mr;
436
437 /* disable interrupts */
438 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
439
440 reg_mr = at91_read(priv, AT91_MR);
441 at91_write(priv, AT91_MR, reg_mr & ~AT91_MR_CANEN);
442
443 at91_transceiver_switch(priv, 0);
444 priv->can.state = state;
445}
446
447/*
448 * theory of operation:
449 *
450 * According to the datasheet priority 0 is the highest priority, 15
451 * is the lowest. If two mailboxes have the same priority level the
452 * message of the mailbox with the lowest number is sent first.
453 *
454 * We use the first TX mailbox (AT91_MB_TX_FIRST) with prio 0, then
455 * the next mailbox with prio 0, and so on, until all mailboxes are
456 * used. Then we start from the beginning with mailbox
457 * AT91_MB_TX_FIRST, but with prio 1, mailbox AT91_MB_TX_FIRST + 1
458 * prio 1. When we reach the last mailbox with prio 15, we have to
459 * stop sending, waiting for all messages to be delivered, then start
460 * again with mailbox AT91_MB_TX_FIRST prio 0.
461 *
462 * We use the priv->tx_next as counter for the next transmission
463 * mailbox, but without the offset AT91_MB_TX_FIRST. The lower bits
464 * encode the mailbox number, the upper 4 bits the mailbox priority:
465 *
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200466 * priv->tx_next = (prio << get_next_prio_shift(priv)) |
467 * (mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700468 *
469 */
470static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
471{
472 struct at91_priv *priv = netdev_priv(dev);
473 struct net_device_stats *stats = &dev->stats;
474 struct can_frame *cf = (struct can_frame *)skb->data;
475 unsigned int mb, prio;
476 u32 reg_mid, reg_mcr;
477
Oliver Hartkopp3ccd4c62010-01-12 02:00:46 -0800478 if (can_dropped_invalid_skb(dev, skb))
479 return NETDEV_TX_OK;
480
David S. Miller99c4a632009-09-25 12:14:43 -0700481 mb = get_tx_next_mb(priv);
482 prio = get_tx_next_prio(priv);
483
484 if (unlikely(!(at91_read(priv, AT91_MSR(mb)) & AT91_MSR_MRDY))) {
485 netif_stop_queue(dev);
486
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000487 netdev_err(dev, "BUG! TX buffer full when queue awake!\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700488 return NETDEV_TX_BUSY;
489 }
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100490 reg_mid = at91_can_id_to_reg_mid(cf->can_id);
David S. Miller99c4a632009-09-25 12:14:43 -0700491 reg_mcr = ((cf->can_id & CAN_RTR_FLAG) ? AT91_MCR_MRTR : 0) |
492 (cf->can_dlc << 16) | AT91_MCR_MTCR;
493
494 /* disable MB while writing ID (see datasheet) */
495 set_mb_mode(priv, mb, AT91_MB_MODE_DISABLED);
496 at91_write(priv, AT91_MID(mb), reg_mid);
497 set_mb_mode_prio(priv, mb, AT91_MB_MODE_TX, prio);
498
499 at91_write(priv, AT91_MDL(mb), *(u32 *)(cf->data + 0));
500 at91_write(priv, AT91_MDH(mb), *(u32 *)(cf->data + 4));
501
502 /* This triggers transmission */
503 at91_write(priv, AT91_MCR(mb), reg_mcr);
504
505 stats->tx_bytes += cf->can_dlc;
David S. Miller99c4a632009-09-25 12:14:43 -0700506
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300507 /* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200508 can_put_echo_skb(skb, dev, mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700509
510 /*
511 * we have to stop the queue and deliver all messages in case
512 * of a prio+mb counter wrap around. This is the case if
513 * tx_next buffer prio and mailbox equals 0.
514 *
515 * also stop the queue if next buffer is still in use
516 * (== not ready)
517 */
518 priv->tx_next++;
519 if (!(at91_read(priv, AT91_MSR(get_tx_next_mb(priv))) &
520 AT91_MSR_MRDY) ||
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200521 (priv->tx_next & get_next_mask(priv)) == 0)
David S. Miller99c4a632009-09-25 12:14:43 -0700522 netif_stop_queue(dev);
523
524 /* Enable interrupt for this mailbox */
525 at91_write(priv, AT91_IER, 1 << mb);
526
527 return NETDEV_TX_OK;
528}
529
530/**
531 * at91_activate_rx_low - activate lower rx mailboxes
532 * @priv: a91 context
533 *
534 * Reenables the lower mailboxes for reception of new CAN messages
535 */
536static inline void at91_activate_rx_low(const struct at91_priv *priv)
537{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200538 u32 mask = get_mb_rx_low_mask(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700539 at91_write(priv, AT91_TCR, mask);
540}
541
542/**
543 * at91_activate_rx_mb - reactive single rx mailbox
544 * @priv: a91 context
545 * @mb: mailbox to reactivate
546 *
547 * Reenables given mailbox for reception of new CAN messages
548 */
549static inline void at91_activate_rx_mb(const struct at91_priv *priv,
550 unsigned int mb)
551{
552 u32 mask = 1 << mb;
553 at91_write(priv, AT91_TCR, mask);
554}
555
556/**
557 * at91_rx_overflow_err - send error frame due to rx overflow
558 * @dev: net device
559 */
560static void at91_rx_overflow_err(struct net_device *dev)
561{
562 struct net_device_stats *stats = &dev->stats;
563 struct sk_buff *skb;
564 struct can_frame *cf;
565
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000566 netdev_dbg(dev, "RX buffer overflow\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700567 stats->rx_over_errors++;
568 stats->rx_errors++;
569
570 skb = alloc_can_err_skb(dev, &cf);
571 if (unlikely(!skb))
572 return;
573
574 cf->can_id |= CAN_ERR_CRTL;
575 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
576 netif_receive_skb(skb);
577
578 stats->rx_packets++;
579 stats->rx_bytes += cf->can_dlc;
580}
581
582/**
583 * at91_read_mb - read CAN msg from mailbox (lowlevel impl)
584 * @dev: net device
585 * @mb: mailbox number to read from
586 * @cf: can frame where to store message
587 *
588 * Reads a CAN message from the given mailbox and stores data into
589 * given can frame. "mb" and "cf" must be valid.
590 */
591static void at91_read_mb(struct net_device *dev, unsigned int mb,
592 struct can_frame *cf)
593{
594 const struct at91_priv *priv = netdev_priv(dev);
595 u32 reg_msr, reg_mid;
596
597 reg_mid = at91_read(priv, AT91_MID(mb));
598 if (reg_mid & AT91_MID_MIDE)
599 cf->can_id = ((reg_mid >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
600 else
601 cf->can_id = (reg_mid >> 18) & CAN_SFF_MASK;
602
603 reg_msr = at91_read(priv, AT91_MSR(mb));
Oliver Hartkoppc7cd6062009-12-12 04:13:21 +0000604 cf->can_dlc = get_can_dlc((reg_msr >> 16) & 0xf);
David S. Miller99c4a632009-09-25 12:14:43 -0700605
Marc Kleine-Buddee14ee402010-10-21 18:39:26 +0200606 if (reg_msr & AT91_MSR_MRTR)
607 cf->can_id |= CAN_RTR_FLAG;
608 else {
609 *(u32 *)(cf->data + 0) = at91_read(priv, AT91_MDL(mb));
610 *(u32 *)(cf->data + 4) = at91_read(priv, AT91_MDH(mb));
611 }
David S. Miller99c4a632009-09-25 12:14:43 -0700612
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000613 /* allow RX of extended frames */
614 at91_write(priv, AT91_MID(mb), AT91_MID_MIDE);
615
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200616 if (unlikely(mb == get_mb_rx_last(priv) && reg_msr & AT91_MSR_MMI))
David S. Miller99c4a632009-09-25 12:14:43 -0700617 at91_rx_overflow_err(dev);
618}
619
620/**
621 * at91_read_msg - read CAN message from mailbox
622 * @dev: net device
623 * @mb: mail box to read from
624 *
625 * Reads a CAN message from given mailbox, and put into linux network
626 * RX queue, does all housekeeping chores (stats, ...)
627 */
628static void at91_read_msg(struct net_device *dev, unsigned int mb)
629{
630 struct net_device_stats *stats = &dev->stats;
631 struct can_frame *cf;
632 struct sk_buff *skb;
633
634 skb = alloc_can_skb(dev, &cf);
635 if (unlikely(!skb)) {
636 stats->rx_dropped++;
637 return;
638 }
639
640 at91_read_mb(dev, mb, cf);
641 netif_receive_skb(skb);
642
643 stats->rx_packets++;
644 stats->rx_bytes += cf->can_dlc;
Fabio Baltieri4723f2b2012-12-18 18:50:59 +0100645
646 can_led_event(dev, CAN_LED_EVENT_RX);
David S. Miller99c4a632009-09-25 12:14:43 -0700647}
648
649/**
650 * at91_poll_rx - read multiple CAN messages from mailboxes
651 * @dev: net device
652 * @quota: max number of pkgs we're allowed to receive
653 *
654 * Theory of Operation:
655 *
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200656 * About 3/4 of the mailboxes (get_mb_rx_first()...get_mb_rx_last())
657 * on the chip are reserved for RX. We split them into 2 groups. The
658 * lower group ranges from get_mb_rx_first() to get_mb_rx_low_last().
David S. Miller99c4a632009-09-25 12:14:43 -0700659 *
660 * Like it or not, but the chip always saves a received CAN message
661 * into the first free mailbox it finds (starting with the
662 * lowest). This makes it very difficult to read the messages in the
663 * right order from the chip. This is how we work around that problem:
664 *
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100665 * The first message goes into mb nr. 1 and issues an interrupt. All
David S. Miller99c4a632009-09-25 12:14:43 -0700666 * rx ints are disabled in the interrupt handler and a napi poll is
667 * scheduled. We read the mailbox, but do _not_ reenable the mb (to
668 * receive another message).
669 *
670 * lower mbxs upper
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100671 * ____^______ __^__
672 * / \ / \
David S. Miller99c4a632009-09-25 12:14:43 -0700673 * +-+-+-+-+-+-+-+-++-+-+-+-+
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100674 * | |x|x|x|x|x|x|x|| | | | |
David S. Miller99c4a632009-09-25 12:14:43 -0700675 * +-+-+-+-+-+-+-+-++-+-+-+-+
676 * 0 0 0 0 0 0 0 0 0 0 1 1 \ mail
677 * 0 1 2 3 4 5 6 7 8 9 0 1 / box
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100678 * ^
679 * |
680 * \
681 * unused, due to chip bug
David S. Miller99c4a632009-09-25 12:14:43 -0700682 *
683 * The variable priv->rx_next points to the next mailbox to read a
684 * message from. As long we're in the lower mailboxes we just read the
685 * mailbox but not reenable it.
686 *
687 * With completion of the last of the lower mailboxes, we reenable the
688 * whole first group, but continue to look for filled mailboxes in the
689 * upper mailboxes. Imagine the second group like overflow mailboxes,
690 * which takes CAN messages if the lower goup is full. While in the
691 * upper group we reenable the mailbox right after reading it. Giving
692 * the chip more room to store messages.
693 *
694 * After finishing we look again in the lower group if we've still
695 * quota.
696 *
697 */
698static int at91_poll_rx(struct net_device *dev, int quota)
699{
700 struct at91_priv *priv = netdev_priv(dev);
701 u32 reg_sr = at91_read(priv, AT91_SR);
702 const unsigned long *addr = (unsigned long *)&reg_sr;
703 unsigned int mb;
704 int received = 0;
705
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200706 if (priv->rx_next > get_mb_rx_low_last(priv) &&
707 reg_sr & get_mb_rx_low_mask(priv))
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000708 netdev_info(dev,
709 "order of incoming frames cannot be guaranteed\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700710
711 again:
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200712 for (mb = find_next_bit(addr, get_mb_tx_first(priv), priv->rx_next);
713 mb < get_mb_tx_first(priv) && quota > 0;
David S. Miller99c4a632009-09-25 12:14:43 -0700714 reg_sr = at91_read(priv, AT91_SR),
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200715 mb = find_next_bit(addr, get_mb_tx_first(priv), ++priv->rx_next)) {
David S. Miller99c4a632009-09-25 12:14:43 -0700716 at91_read_msg(dev, mb);
717
718 /* reactivate mailboxes */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200719 if (mb == get_mb_rx_low_last(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700720 /* all lower mailboxed, if just finished it */
721 at91_activate_rx_low(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200722 else if (mb > get_mb_rx_low_last(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700723 /* only the mailbox we read */
724 at91_activate_rx_mb(priv, mb);
725
726 received++;
727 quota--;
728 }
729
730 /* upper group completed, look again in lower */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200731 if (priv->rx_next > get_mb_rx_low_last(priv) &&
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200732 quota > 0 && mb > get_mb_rx_last(priv)) {
733 priv->rx_next = get_mb_rx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700734 goto again;
735 }
736
737 return received;
738}
739
740static void at91_poll_err_frame(struct net_device *dev,
741 struct can_frame *cf, u32 reg_sr)
742{
743 struct at91_priv *priv = netdev_priv(dev);
744
745 /* CRC error */
746 if (reg_sr & AT91_IRQ_CERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000747 netdev_dbg(dev, "CERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700748 dev->stats.rx_errors++;
749 priv->can.can_stats.bus_error++;
750 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
751 }
752
753 /* Stuffing Error */
754 if (reg_sr & AT91_IRQ_SERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000755 netdev_dbg(dev, "SERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700756 dev->stats.rx_errors++;
757 priv->can.can_stats.bus_error++;
758 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
759 cf->data[2] |= CAN_ERR_PROT_STUFF;
760 }
761
762 /* Acknowledgement Error */
763 if (reg_sr & AT91_IRQ_AERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000764 netdev_dbg(dev, "AERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700765 dev->stats.tx_errors++;
766 cf->can_id |= CAN_ERR_ACK;
767 }
768
769 /* Form error */
770 if (reg_sr & AT91_IRQ_FERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000771 netdev_dbg(dev, "FERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700772 dev->stats.rx_errors++;
773 priv->can.can_stats.bus_error++;
774 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
775 cf->data[2] |= CAN_ERR_PROT_FORM;
776 }
777
778 /* Bit Error */
779 if (reg_sr & AT91_IRQ_BERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000780 netdev_dbg(dev, "BERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700781 dev->stats.tx_errors++;
782 priv->can.can_stats.bus_error++;
783 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
784 cf->data[2] |= CAN_ERR_PROT_BIT;
785 }
786}
787
788static int at91_poll_err(struct net_device *dev, int quota, u32 reg_sr)
789{
790 struct sk_buff *skb;
791 struct can_frame *cf;
792
793 if (quota == 0)
794 return 0;
795
796 skb = alloc_can_err_skb(dev, &cf);
797 if (unlikely(!skb))
798 return 0;
799
800 at91_poll_err_frame(dev, cf, reg_sr);
801 netif_receive_skb(skb);
802
David S. Miller99c4a632009-09-25 12:14:43 -0700803 dev->stats.rx_packets++;
804 dev->stats.rx_bytes += cf->can_dlc;
805
806 return 1;
807}
808
809static int at91_poll(struct napi_struct *napi, int quota)
810{
811 struct net_device *dev = napi->dev;
812 const struct at91_priv *priv = netdev_priv(dev);
813 u32 reg_sr = at91_read(priv, AT91_SR);
814 int work_done = 0;
815
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200816 if (reg_sr & get_irq_mb_rx(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700817 work_done += at91_poll_rx(dev, quota - work_done);
818
819 /*
820 * The error bits are clear on read,
821 * so use saved value from irq handler.
822 */
823 reg_sr |= priv->reg_sr;
824 if (reg_sr & AT91_IRQ_ERR_FRAME)
825 work_done += at91_poll_err(dev, quota - work_done, reg_sr);
826
827 if (work_done < quota) {
828 /* enable IRQs for frame errors and all mailboxes >= rx_next */
829 u32 reg_ier = AT91_IRQ_ERR_FRAME;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200830 reg_ier |= get_irq_mb_rx(priv) & ~AT91_MB_MASK(priv->rx_next);
David S. Miller99c4a632009-09-25 12:14:43 -0700831
832 napi_complete(napi);
833 at91_write(priv, AT91_IER, reg_ier);
834 }
835
836 return work_done;
837}
838
839/*
840 * theory of operation:
841 *
842 * priv->tx_echo holds the number of the oldest can_frame put for
843 * transmission into the hardware, but not yet ACKed by the CAN tx
844 * complete IRQ.
845 *
846 * We iterate from priv->tx_echo to priv->tx_next and check if the
847 * packet has been transmitted, echo it back to the CAN framework. If
848 * we discover a not yet transmitted package, stop looking for more.
849 *
850 */
851static void at91_irq_tx(struct net_device *dev, u32 reg_sr)
852{
853 struct at91_priv *priv = netdev_priv(dev);
854 u32 reg_msr;
855 unsigned int mb;
856
857 /* masking of reg_sr not needed, already done by at91_irq */
858
859 for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
860 mb = get_tx_echo_mb(priv);
861
862 /* no event in mailbox? */
863 if (!(reg_sr & (1 << mb)))
864 break;
865
866 /* Disable irq for this TX mailbox */
867 at91_write(priv, AT91_IDR, 1 << mb);
868
869 /*
870 * only echo if mailbox signals us a transfer
871 * complete (MSR_MRDY). Otherwise it's a tansfer
872 * abort. "can_bus_off()" takes care about the skbs
873 * parked in the echo queue.
874 */
875 reg_msr = at91_read(priv, AT91_MSR(mb));
876 if (likely(reg_msr & AT91_MSR_MRDY &&
877 ~reg_msr & AT91_MSR_MABT)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300878 /* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200879 can_get_echo_skb(dev, mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700880 dev->stats.tx_packets++;
Fabio Baltieri4723f2b2012-12-18 18:50:59 +0100881 can_led_event(dev, CAN_LED_EVENT_TX);
David S. Miller99c4a632009-09-25 12:14:43 -0700882 }
883 }
884
885 /*
886 * restart queue if we don't have a wrap around but restart if
887 * we get a TX int for the last can frame directly before a
888 * wrap around.
889 */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200890 if ((priv->tx_next & get_next_mask(priv)) != 0 ||
891 (priv->tx_echo & get_next_mask(priv)) == 0)
David S. Miller99c4a632009-09-25 12:14:43 -0700892 netif_wake_queue(dev);
893}
894
895static void at91_irq_err_state(struct net_device *dev,
896 struct can_frame *cf, enum can_state new_state)
897{
898 struct at91_priv *priv = netdev_priv(dev);
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000899 u32 reg_idr = 0, reg_ier = 0;
900 struct can_berr_counter bec;
David S. Miller99c4a632009-09-25 12:14:43 -0700901
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000902 at91_get_berr_counter(dev, &bec);
David S. Miller99c4a632009-09-25 12:14:43 -0700903
904 switch (priv->can.state) {
905 case CAN_STATE_ERROR_ACTIVE:
906 /*
907 * from: ERROR_ACTIVE
908 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
909 * => : there was a warning int
910 */
911 if (new_state >= CAN_STATE_ERROR_WARNING &&
912 new_state <= CAN_STATE_BUS_OFF) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000913 netdev_dbg(dev, "Error Warning IRQ\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700914 priv->can.can_stats.error_warning++;
915
916 cf->can_id |= CAN_ERR_CRTL;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000917 cf->data[1] = (bec.txerr > bec.rxerr) ?
David S. Miller99c4a632009-09-25 12:14:43 -0700918 CAN_ERR_CRTL_TX_WARNING :
919 CAN_ERR_CRTL_RX_WARNING;
920 }
921 case CAN_STATE_ERROR_WARNING: /* fallthrough */
922 /*
923 * from: ERROR_ACTIVE, ERROR_WARNING
924 * to : ERROR_PASSIVE, BUS_OFF
925 * => : error passive int
926 */
927 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
928 new_state <= CAN_STATE_BUS_OFF) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000929 netdev_dbg(dev, "Error Passive IRQ\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700930 priv->can.can_stats.error_passive++;
931
932 cf->can_id |= CAN_ERR_CRTL;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000933 cf->data[1] = (bec.txerr > bec.rxerr) ?
David S. Miller99c4a632009-09-25 12:14:43 -0700934 CAN_ERR_CRTL_TX_PASSIVE :
935 CAN_ERR_CRTL_RX_PASSIVE;
936 }
937 break;
938 case CAN_STATE_BUS_OFF:
939 /*
940 * from: BUS_OFF
941 * to : ERROR_ACTIVE, ERROR_WARNING, ERROR_PASSIVE
942 */
943 if (new_state <= CAN_STATE_ERROR_PASSIVE) {
944 cf->can_id |= CAN_ERR_RESTARTED;
945
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000946 netdev_dbg(dev, "restarted\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700947 priv->can.can_stats.restarts++;
948
949 netif_carrier_on(dev);
950 netif_wake_queue(dev);
951 }
952 break;
953 default:
954 break;
955 }
956
957
958 /* process state changes depending on the new state */
959 switch (new_state) {
960 case CAN_STATE_ERROR_ACTIVE:
961 /*
962 * actually we want to enable AT91_IRQ_WARN here, but
963 * it screws up the system under certain
964 * circumstances. so just enable AT91_IRQ_ERRP, thus
965 * the "fallthrough"
966 */
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000967 netdev_dbg(dev, "Error Active\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700968 cf->can_id |= CAN_ERR_PROT;
969 cf->data[2] = CAN_ERR_PROT_ACTIVE;
970 case CAN_STATE_ERROR_WARNING: /* fallthrough */
971 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_BOFF;
972 reg_ier = AT91_IRQ_ERRP;
973 break;
974 case CAN_STATE_ERROR_PASSIVE:
975 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_ERRP;
976 reg_ier = AT91_IRQ_BOFF;
977 break;
978 case CAN_STATE_BUS_OFF:
979 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_ERRP |
980 AT91_IRQ_WARN | AT91_IRQ_BOFF;
981 reg_ier = 0;
982
983 cf->can_id |= CAN_ERR_BUSOFF;
984
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000985 netdev_dbg(dev, "bus-off\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700986 netif_carrier_off(dev);
987 priv->can.can_stats.bus_off++;
988
989 /* turn off chip, if restart is disabled */
990 if (!priv->can.restart_ms) {
991 at91_chip_stop(dev, CAN_STATE_BUS_OFF);
992 return;
993 }
994 break;
995 default:
996 break;
997 }
998
999 at91_write(priv, AT91_IDR, reg_idr);
1000 at91_write(priv, AT91_IER, reg_ier);
1001}
1002
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001003static int at91_get_state_by_bec(const struct net_device *dev,
1004 enum can_state *state)
1005{
1006 struct can_berr_counter bec;
1007 int err;
1008
1009 err = at91_get_berr_counter(dev, &bec);
1010 if (err)
1011 return err;
1012
1013 if (bec.txerr < 96 && bec.rxerr < 96)
1014 *state = CAN_STATE_ERROR_ACTIVE;
1015 else if (bec.txerr < 128 && bec.rxerr < 128)
1016 *state = CAN_STATE_ERROR_WARNING;
1017 else if (bec.txerr < 256 && bec.rxerr < 256)
1018 *state = CAN_STATE_ERROR_PASSIVE;
1019 else
1020 *state = CAN_STATE_BUS_OFF;
1021
1022 return 0;
1023}
1024
1025
David S. Miller99c4a632009-09-25 12:14:43 -07001026static void at91_irq_err(struct net_device *dev)
1027{
1028 struct at91_priv *priv = netdev_priv(dev);
1029 struct sk_buff *skb;
1030 struct can_frame *cf;
1031 enum can_state new_state;
1032 u32 reg_sr;
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001033 int err;
David S. Miller99c4a632009-09-25 12:14:43 -07001034
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001035 if (at91_is_sam9263(priv)) {
1036 reg_sr = at91_read(priv, AT91_SR);
David S. Miller99c4a632009-09-25 12:14:43 -07001037
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001038 /* we need to look at the unmasked reg_sr */
1039 if (unlikely(reg_sr & AT91_IRQ_BOFF))
1040 new_state = CAN_STATE_BUS_OFF;
1041 else if (unlikely(reg_sr & AT91_IRQ_ERRP))
1042 new_state = CAN_STATE_ERROR_PASSIVE;
1043 else if (unlikely(reg_sr & AT91_IRQ_WARN))
1044 new_state = CAN_STATE_ERROR_WARNING;
1045 else if (likely(reg_sr & AT91_IRQ_ERRA))
1046 new_state = CAN_STATE_ERROR_ACTIVE;
1047 else {
1048 netdev_err(dev, "BUG! hardware in undefined state\n");
1049 return;
1050 }
1051 } else {
1052 err = at91_get_state_by_bec(dev, &new_state);
1053 if (err)
1054 return;
David S. Miller99c4a632009-09-25 12:14:43 -07001055 }
1056
1057 /* state hasn't changed */
1058 if (likely(new_state == priv->can.state))
1059 return;
1060
1061 skb = alloc_can_err_skb(dev, &cf);
1062 if (unlikely(!skb))
1063 return;
1064
1065 at91_irq_err_state(dev, cf, new_state);
1066 netif_rx(skb);
1067
David S. Miller99c4a632009-09-25 12:14:43 -07001068 dev->stats.rx_packets++;
1069 dev->stats.rx_bytes += cf->can_dlc;
1070
1071 priv->can.state = new_state;
1072}
1073
1074/*
1075 * interrupt handler
1076 */
1077static irqreturn_t at91_irq(int irq, void *dev_id)
1078{
1079 struct net_device *dev = dev_id;
1080 struct at91_priv *priv = netdev_priv(dev);
1081 irqreturn_t handled = IRQ_NONE;
1082 u32 reg_sr, reg_imr;
1083
1084 reg_sr = at91_read(priv, AT91_SR);
1085 reg_imr = at91_read(priv, AT91_IMR);
1086
1087 /* Ignore masked interrupts */
1088 reg_sr &= reg_imr;
1089 if (!reg_sr)
1090 goto exit;
1091
1092 handled = IRQ_HANDLED;
1093
1094 /* Receive or error interrupt? -> napi */
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001095 if (reg_sr & (get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME)) {
David S. Miller99c4a632009-09-25 12:14:43 -07001096 /*
1097 * The error bits are clear on read,
1098 * save for later use.
1099 */
1100 priv->reg_sr = reg_sr;
1101 at91_write(priv, AT91_IDR,
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001102 get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME);
David S. Miller99c4a632009-09-25 12:14:43 -07001103 napi_schedule(&priv->napi);
1104 }
1105
1106 /* Transmission complete interrupt */
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001107 if (reg_sr & get_irq_mb_tx(priv))
David S. Miller99c4a632009-09-25 12:14:43 -07001108 at91_irq_tx(dev, reg_sr);
1109
1110 at91_irq_err(dev);
1111
1112 exit:
1113 return handled;
1114}
1115
1116static int at91_open(struct net_device *dev)
1117{
1118 struct at91_priv *priv = netdev_priv(dev);
1119 int err;
1120
1121 clk_enable(priv->clk);
1122
1123 /* check or determine and set bittime */
1124 err = open_candev(dev);
1125 if (err)
1126 goto out;
1127
1128 /* register interrupt handler */
1129 if (request_irq(dev->irq, at91_irq, IRQF_SHARED,
1130 dev->name, dev)) {
1131 err = -EAGAIN;
1132 goto out_close;
1133 }
1134
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001135 can_led_event(dev, CAN_LED_EVENT_OPEN);
1136
David S. Miller99c4a632009-09-25 12:14:43 -07001137 /* start chip and queuing */
1138 at91_chip_start(dev);
1139 napi_enable(&priv->napi);
1140 netif_start_queue(dev);
1141
1142 return 0;
1143
1144 out_close:
1145 close_candev(dev);
1146 out:
1147 clk_disable(priv->clk);
1148
1149 return err;
1150}
1151
1152/*
1153 * stop CAN bus activity
1154 */
1155static int at91_close(struct net_device *dev)
1156{
1157 struct at91_priv *priv = netdev_priv(dev);
1158
1159 netif_stop_queue(dev);
1160 napi_disable(&priv->napi);
1161 at91_chip_stop(dev, CAN_STATE_STOPPED);
1162
1163 free_irq(dev->irq, dev);
1164 clk_disable(priv->clk);
1165
1166 close_candev(dev);
1167
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001168 can_led_event(dev, CAN_LED_EVENT_STOP);
1169
David S. Miller99c4a632009-09-25 12:14:43 -07001170 return 0;
1171}
1172
1173static int at91_set_mode(struct net_device *dev, enum can_mode mode)
1174{
1175 switch (mode) {
1176 case CAN_MODE_START:
1177 at91_chip_start(dev);
1178 netif_wake_queue(dev);
1179 break;
1180
1181 default:
1182 return -EOPNOTSUPP;
1183 }
1184
1185 return 0;
1186}
1187
1188static const struct net_device_ops at91_netdev_ops = {
1189 .ndo_open = at91_open,
1190 .ndo_stop = at91_close,
1191 .ndo_start_xmit = at91_start_xmit,
1192};
1193
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001194static ssize_t at91_sysfs_show_mb0_id(struct device *dev,
1195 struct device_attribute *attr, char *buf)
1196{
1197 struct at91_priv *priv = netdev_priv(to_net_dev(dev));
1198
1199 if (priv->mb0_id & CAN_EFF_FLAG)
1200 return snprintf(buf, PAGE_SIZE, "0x%08x\n", priv->mb0_id);
1201 else
1202 return snprintf(buf, PAGE_SIZE, "0x%03x\n", priv->mb0_id);
1203}
1204
1205static ssize_t at91_sysfs_set_mb0_id(struct device *dev,
1206 struct device_attribute *attr, const char *buf, size_t count)
1207{
1208 struct net_device *ndev = to_net_dev(dev);
1209 struct at91_priv *priv = netdev_priv(ndev);
1210 unsigned long can_id;
1211 ssize_t ret;
1212 int err;
1213
1214 rtnl_lock();
1215
1216 if (ndev->flags & IFF_UP) {
1217 ret = -EBUSY;
1218 goto out;
1219 }
1220
1221 err = strict_strtoul(buf, 0, &can_id);
1222 if (err) {
1223 ret = err;
1224 goto out;
1225 }
1226
1227 if (can_id & CAN_EFF_FLAG)
1228 can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
1229 else
1230 can_id &= CAN_SFF_MASK;
1231
1232 priv->mb0_id = can_id;
1233 ret = count;
1234
1235 out:
1236 rtnl_unlock();
1237 return ret;
1238}
1239
Vasiliy Kulikovfef52b02011-02-04 02:23:50 +00001240static DEVICE_ATTR(mb0_id, S_IWUSR | S_IRUGO,
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001241 at91_sysfs_show_mb0_id, at91_sysfs_set_mb0_id);
1242
1243static struct attribute *at91_sysfs_attrs[] = {
1244 &dev_attr_mb0_id.attr,
1245 NULL,
1246};
1247
1248static struct attribute_group at91_sysfs_attr_group = {
1249 .attrs = at91_sysfs_attrs,
1250};
1251
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001252static int at91_can_probe(struct platform_device *pdev)
David S. Miller99c4a632009-09-25 12:14:43 -07001253{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001254 const struct at91_devtype_data *devtype_data;
1255 enum at91_devtype devtype;
David S. Miller99c4a632009-09-25 12:14:43 -07001256 struct net_device *dev;
1257 struct at91_priv *priv;
1258 struct resource *res;
1259 struct clk *clk;
1260 void __iomem *addr;
1261 int err, irq;
1262
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001263 devtype = pdev->id_entry->driver_data;
1264 devtype_data = &at91_devtype_data[devtype];
1265
David S. Miller99c4a632009-09-25 12:14:43 -07001266 clk = clk_get(&pdev->dev, "can_clk");
1267 if (IS_ERR(clk)) {
1268 dev_err(&pdev->dev, "no clock defined\n");
1269 err = -ENODEV;
1270 goto exit;
1271 }
1272
1273 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1274 irq = platform_get_irq(pdev, 0);
Uwe Kleine-König4773a472009-12-18 20:31:56 -08001275 if (!res || irq <= 0) {
David S. Miller99c4a632009-09-25 12:14:43 -07001276 err = -ENODEV;
1277 goto exit_put;
1278 }
1279
1280 if (!request_mem_region(res->start,
1281 resource_size(res),
1282 pdev->name)) {
1283 err = -EBUSY;
1284 goto exit_put;
1285 }
1286
1287 addr = ioremap_nocache(res->start, resource_size(res));
1288 if (!addr) {
1289 err = -ENOMEM;
1290 goto exit_release;
1291 }
1292
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001293 dev = alloc_candev(sizeof(struct at91_priv),
1294 1 << devtype_data->tx_shift);
David S. Miller99c4a632009-09-25 12:14:43 -07001295 if (!dev) {
1296 err = -ENOMEM;
1297 goto exit_iounmap;
1298 }
1299
1300 dev->netdev_ops = &at91_netdev_ops;
1301 dev->irq = irq;
1302 dev->flags |= IFF_ECHO;
1303
1304 priv = netdev_priv(dev);
1305 priv->can.clock.freq = clk_get_rate(clk);
1306 priv->can.bittiming_const = &at91_bittiming_const;
David S. Miller99c4a632009-09-25 12:14:43 -07001307 priv->can.do_set_mode = at91_set_mode;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +00001308 priv->can.do_get_berr_counter = at91_get_berr_counter;
Christian Pellegrinad72c342010-01-14 07:08:34 +00001309 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
David S. Miller99c4a632009-09-25 12:14:43 -07001310 priv->dev = dev;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001311 priv->reg_base = addr;
1312 priv->devtype_data = *devtype_data;
1313 priv->devtype_data.type = devtype;
David S. Miller99c4a632009-09-25 12:14:43 -07001314 priv->clk = clk;
1315 priv->pdata = pdev->dev.platform_data;
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001316 priv->mb0_id = 0x7ff;
David S. Miller99c4a632009-09-25 12:14:43 -07001317
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001318 netif_napi_add(dev, &priv->napi, at91_poll, get_mb_rx_num(priv));
David S. Miller99c4a632009-09-25 12:14:43 -07001319
Marc Kleine-Budde07a648e2011-06-01 00:20:17 +02001320 if (at91_is_sam9263(priv))
1321 dev->sysfs_groups[0] = &at91_sysfs_attr_group;
1322
David S. Miller99c4a632009-09-25 12:14:43 -07001323 dev_set_drvdata(&pdev->dev, dev);
1324 SET_NETDEV_DEV(dev, &pdev->dev);
1325
1326 err = register_candev(dev);
1327 if (err) {
1328 dev_err(&pdev->dev, "registering netdev failed\n");
1329 goto exit_free;
1330 }
1331
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001332 devm_can_led_init(dev);
1333
David S. Miller99c4a632009-09-25 12:14:43 -07001334 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1335 priv->reg_base, dev->irq);
1336
1337 return 0;
1338
1339 exit_free:
Marc Kleine-Budde759a6c72010-10-21 01:01:15 +00001340 free_candev(dev);
David S. Miller99c4a632009-09-25 12:14:43 -07001341 exit_iounmap:
1342 iounmap(addr);
1343 exit_release:
1344 release_mem_region(res->start, resource_size(res));
1345 exit_put:
1346 clk_put(clk);
1347 exit:
1348 return err;
1349}
1350
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001351static int at91_can_remove(struct platform_device *pdev)
David S. Miller99c4a632009-09-25 12:14:43 -07001352{
1353 struct net_device *dev = platform_get_drvdata(pdev);
1354 struct at91_priv *priv = netdev_priv(dev);
1355 struct resource *res;
1356
1357 unregister_netdev(dev);
1358
1359 platform_set_drvdata(pdev, NULL);
1360
David S. Miller99c4a632009-09-25 12:14:43 -07001361 iounmap(priv->reg_base);
1362
1363 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1364 release_mem_region(res->start, resource_size(res));
1365
1366 clk_put(priv->clk);
1367
Marc Kleine-Budde759a6c72010-10-21 01:01:15 +00001368 free_candev(dev);
1369
David S. Miller99c4a632009-09-25 12:14:43 -07001370 return 0;
1371}
1372
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001373static const struct platform_device_id at91_can_id_table[] = {
1374 {
1375 .name = "at91_can",
1376 .driver_data = AT91_DEVTYPE_SAM9263,
1377 }, {
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001378 .name = "at91sam9x5_can",
1379 .driver_data = AT91_DEVTYPE_SAM9X5,
1380 }, {
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001381 /* sentinel */
1382 }
1383};
Marc Kleine-Budde09ca71c2012-10-12 09:44:51 +02001384MODULE_DEVICE_TABLE(platform, at91_can_id_table);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001385
David S. Miller99c4a632009-09-25 12:14:43 -07001386static struct platform_driver at91_can_driver = {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +01001387 .probe = at91_can_probe,
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001388 .remove = at91_can_remove,
Marc Kleine-Budde44d85662011-01-30 22:14:49 +01001389 .driver = {
1390 .name = KBUILD_MODNAME,
1391 .owner = THIS_MODULE,
David S. Miller99c4a632009-09-25 12:14:43 -07001392 },
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001393 .id_table = at91_can_id_table,
David S. Miller99c4a632009-09-25 12:14:43 -07001394};
1395
Axel Lin871d3372011-11-27 15:42:31 +00001396module_platform_driver(at91_can_driver);
David S. Miller99c4a632009-09-25 12:14:43 -07001397
1398MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
1399MODULE_LICENSE("GPL v2");
Marc Kleine-Budde00389b02010-10-21 01:01:22 +00001400MODULE_DESCRIPTION(KBUILD_MODNAME " CAN netdevice driver");