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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>
Ludovic Desroches3078cde72013-03-11 18:26:03 +010030#include <linux/of.h>
David S. Miller99c4a632009-09-25 12:14:43 -070031#include <linux/platform_device.h>
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +010032#include <linux/rtnetlink.h>
David S. Miller99c4a632009-09-25 12:14:43 -070033#include <linux/skbuff.h>
34#include <linux/spinlock.h>
35#include <linux/string.h>
36#include <linux/types.h>
Jean-Christophe PLAGNIOL-VILLARDbcd23602012-10-30 05:12:23 +080037#include <linux/platform_data/atmel.h>
David S. Miller99c4a632009-09-25 12:14:43 -070038
David S. Miller99c4a632009-09-25 12:14:43 -070039#include <linux/can/dev.h>
40#include <linux/can/error.h>
Fabio Baltieri4723f2b2012-12-18 18:50:59 +010041#include <linux/can/led.h>
David S. Miller99c4a632009-09-25 12:14:43 -070042
Marc Kleine-Buddeb0499942011-05-03 16:37:16 +020043#define AT91_MB_MASK(i) ((1 << (i)) - 1)
David S. Miller99c4a632009-09-25 12:14:43 -070044
45/* Common registers */
46enum at91_reg {
47 AT91_MR = 0x000,
48 AT91_IER = 0x004,
49 AT91_IDR = 0x008,
50 AT91_IMR = 0x00C,
51 AT91_SR = 0x010,
52 AT91_BR = 0x014,
53 AT91_TIM = 0x018,
54 AT91_TIMESTP = 0x01C,
55 AT91_ECR = 0x020,
56 AT91_TCR = 0x024,
57 AT91_ACR = 0x028,
58};
59
60/* Mailbox registers (0 <= i <= 15) */
61#define AT91_MMR(i) (enum at91_reg)(0x200 + ((i) * 0x20))
62#define AT91_MAM(i) (enum at91_reg)(0x204 + ((i) * 0x20))
63#define AT91_MID(i) (enum at91_reg)(0x208 + ((i) * 0x20))
64#define AT91_MFID(i) (enum at91_reg)(0x20C + ((i) * 0x20))
65#define AT91_MSR(i) (enum at91_reg)(0x210 + ((i) * 0x20))
66#define AT91_MDL(i) (enum at91_reg)(0x214 + ((i) * 0x20))
67#define AT91_MDH(i) (enum at91_reg)(0x218 + ((i) * 0x20))
68#define AT91_MCR(i) (enum at91_reg)(0x21C + ((i) * 0x20))
69
70/* Register bits */
71#define AT91_MR_CANEN BIT(0)
72#define AT91_MR_LPM BIT(1)
73#define AT91_MR_ABM BIT(2)
74#define AT91_MR_OVL BIT(3)
75#define AT91_MR_TEOF BIT(4)
76#define AT91_MR_TTM BIT(5)
77#define AT91_MR_TIMFRZ BIT(6)
78#define AT91_MR_DRPT BIT(7)
79
80#define AT91_SR_RBSY BIT(29)
81
82#define AT91_MMR_PRIO_SHIFT (16)
83
84#define AT91_MID_MIDE BIT(29)
85
86#define AT91_MSR_MRTR BIT(20)
87#define AT91_MSR_MABT BIT(22)
88#define AT91_MSR_MRDY BIT(23)
89#define AT91_MSR_MMI BIT(24)
90
91#define AT91_MCR_MRTR BIT(20)
92#define AT91_MCR_MTCR BIT(23)
93
94/* Mailbox Modes */
95enum at91_mb_mode {
96 AT91_MB_MODE_DISABLED = 0,
97 AT91_MB_MODE_RX = 1,
98 AT91_MB_MODE_RX_OVRWR = 2,
99 AT91_MB_MODE_TX = 3,
100 AT91_MB_MODE_CONSUMER = 4,
101 AT91_MB_MODE_PRODUCER = 5,
102};
103
104/* Interrupt mask bits */
David S. Miller99c4a632009-09-25 12:14:43 -0700105#define AT91_IRQ_ERRA (1 << 16)
106#define AT91_IRQ_WARN (1 << 17)
107#define AT91_IRQ_ERRP (1 << 18)
108#define AT91_IRQ_BOFF (1 << 19)
109#define AT91_IRQ_SLEEP (1 << 20)
110#define AT91_IRQ_WAKEUP (1 << 21)
111#define AT91_IRQ_TOVF (1 << 22)
112#define AT91_IRQ_TSTP (1 << 23)
113#define AT91_IRQ_CERR (1 << 24)
114#define AT91_IRQ_SERR (1 << 25)
115#define AT91_IRQ_AERR (1 << 26)
116#define AT91_IRQ_FERR (1 << 27)
117#define AT91_IRQ_BERR (1 << 28)
118
119#define AT91_IRQ_ERR_ALL (0x1fff0000)
120#define AT91_IRQ_ERR_FRAME (AT91_IRQ_CERR | AT91_IRQ_SERR | \
121 AT91_IRQ_AERR | AT91_IRQ_FERR | AT91_IRQ_BERR)
122#define AT91_IRQ_ERR_LINE (AT91_IRQ_ERRA | AT91_IRQ_WARN | \
123 AT91_IRQ_ERRP | AT91_IRQ_BOFF)
124
125#define AT91_IRQ_ALL (0x1fffffff)
126
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200127enum at91_devtype {
128 AT91_DEVTYPE_SAM9263,
Marc Kleine-Budde6388b392011-04-17 00:08:45 +0200129 AT91_DEVTYPE_SAM9X5,
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200130};
131
132struct at91_devtype_data {
133 unsigned int rx_first;
134 unsigned int rx_split;
135 unsigned int rx_last;
136 unsigned int tx_shift;
137 enum at91_devtype type;
138};
139
David S. Miller99c4a632009-09-25 12:14:43 -0700140struct at91_priv {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100141 struct can_priv can; /* must be the first member! */
142 struct net_device *dev;
143 struct napi_struct napi;
David S. Miller99c4a632009-09-25 12:14:43 -0700144
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100145 void __iomem *reg_base;
David S. Miller99c4a632009-09-25 12:14:43 -0700146
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100147 u32 reg_sr;
148 unsigned int tx_next;
149 unsigned int tx_echo;
150 unsigned int rx_next;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200151 struct at91_devtype_data devtype_data;
David S. Miller99c4a632009-09-25 12:14:43 -0700152
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100153 struct clk *clk;
154 struct at91_can_data *pdata;
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100155
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100156 canid_t mb0_id;
David S. Miller99c4a632009-09-25 12:14:43 -0700157};
158
Ludovic Desroches3078cde72013-03-11 18:26:03 +0100159static const struct at91_devtype_data at91_at91sam9263_data = {
160 .rx_first = 1,
161 .rx_split = 8,
162 .rx_last = 11,
163 .tx_shift = 2,
164 .type = AT91_DEVTYPE_SAM9263,
165};
166
167static const struct at91_devtype_data at91_at91sam9x5_data = {
168 .rx_first = 0,
169 .rx_split = 4,
170 .rx_last = 5,
171 .tx_shift = 1,
172 .type = AT91_DEVTYPE_SAM9X5,
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200173};
174
Marc Kleine-Budde194b9a42012-07-16 12:58:31 +0200175static const struct can_bittiming_const at91_bittiming_const = {
Marc Kleine-Budde00389b02010-10-21 01:01:22 +0000176 .name = KBUILD_MODNAME,
David S. Miller99c4a632009-09-25 12:14:43 -0700177 .tseg1_min = 4,
178 .tseg1_max = 16,
179 .tseg2_min = 2,
180 .tseg2_max = 8,
181 .sjw_max = 4,
182 .brp_min = 2,
183 .brp_max = 128,
184 .brp_inc = 1,
185};
186
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200187#define AT91_IS(_model) \
188static inline int at91_is_sam##_model(const struct at91_priv *priv) \
189{ \
190 return priv->devtype_data.type == AT91_DEVTYPE_SAM##_model; \
191}
192
193AT91_IS(9263);
Marc Kleine-Budde6388b392011-04-17 00:08:45 +0200194AT91_IS(9X5);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200195
196static inline unsigned int get_mb_rx_first(const struct at91_priv *priv)
197{
198 return priv->devtype_data.rx_first;
199}
200
201static inline unsigned int get_mb_rx_last(const struct at91_priv *priv)
202{
203 return priv->devtype_data.rx_last;
204}
205
206static inline unsigned int get_mb_rx_split(const struct at91_priv *priv)
207{
208 return priv->devtype_data.rx_split;
209}
210
211static inline unsigned int get_mb_rx_num(const struct at91_priv *priv)
212{
213 return get_mb_rx_last(priv) - get_mb_rx_first(priv) + 1;
214}
215
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200216static inline unsigned int get_mb_rx_low_last(const struct at91_priv *priv)
217{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200218 return get_mb_rx_split(priv) - 1;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200219}
220
221static inline unsigned int get_mb_rx_low_mask(const struct at91_priv *priv)
222{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200223 return AT91_MB_MASK(get_mb_rx_split(priv)) &
224 ~AT91_MB_MASK(get_mb_rx_first(priv));
225}
226
227static inline unsigned int get_mb_tx_shift(const struct at91_priv *priv)
228{
229 return priv->devtype_data.tx_shift;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200230}
231
232static inline unsigned int get_mb_tx_num(const struct at91_priv *priv)
233{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200234 return 1 << get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200235}
236
237static inline unsigned int get_mb_tx_first(const struct at91_priv *priv)
238{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200239 return get_mb_rx_last(priv) + 1;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200240}
241
242static inline unsigned int get_mb_tx_last(const struct at91_priv *priv)
243{
244 return get_mb_tx_first(priv) + get_mb_tx_num(priv) - 1;
245}
246
247static inline unsigned int get_next_prio_shift(const struct at91_priv *priv)
248{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200249 return get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200250}
251
252static inline unsigned int get_next_prio_mask(const struct at91_priv *priv)
253{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200254 return 0xf << get_mb_tx_shift(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200255}
256
257static inline unsigned int get_next_mb_mask(const struct at91_priv *priv)
258{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200259 return AT91_MB_MASK(get_mb_tx_shift(priv));
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200260}
261
262static inline unsigned int get_next_mask(const struct at91_priv *priv)
263{
264 return get_next_mb_mask(priv) | get_next_prio_mask(priv);
265}
266
267static inline unsigned int get_irq_mb_rx(const struct at91_priv *priv)
268{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200269 return AT91_MB_MASK(get_mb_rx_last(priv) + 1) &
270 ~AT91_MB_MASK(get_mb_rx_first(priv));
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200271}
272
273static inline unsigned int get_irq_mb_tx(const struct at91_priv *priv)
274{
275 return AT91_MB_MASK(get_mb_tx_last(priv) + 1) &
276 ~AT91_MB_MASK(get_mb_tx_first(priv));
277}
278
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200279static inline unsigned int get_tx_next_mb(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700280{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200281 return (priv->tx_next & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700282}
283
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200284static inline unsigned int get_tx_next_prio(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700285{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200286 return (priv->tx_next >> get_next_prio_shift(priv)) & 0xf;
David S. Miller99c4a632009-09-25 12:14:43 -0700287}
288
Marc Kleine-Budde9c2e0a62011-05-03 17:47:55 +0200289static inline unsigned int get_tx_echo_mb(const struct at91_priv *priv)
David S. Miller99c4a632009-09-25 12:14:43 -0700290{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200291 return (priv->tx_echo & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700292}
293
294static inline u32 at91_read(const struct at91_priv *priv, enum at91_reg reg)
295{
Marc Kleine-Budde7672fe72010-10-21 01:01:20 +0000296 return __raw_readl(priv->reg_base + reg);
David S. Miller99c4a632009-09-25 12:14:43 -0700297}
298
299static inline void at91_write(const struct at91_priv *priv, enum at91_reg reg,
300 u32 value)
301{
Marc Kleine-Budde7672fe72010-10-21 01:01:20 +0000302 __raw_writel(value, priv->reg_base + reg);
David S. Miller99c4a632009-09-25 12:14:43 -0700303}
304
305static inline void set_mb_mode_prio(const struct at91_priv *priv,
306 unsigned int mb, enum at91_mb_mode mode, int prio)
307{
308 at91_write(priv, AT91_MMR(mb), (mode << 24) | (prio << 16));
309}
310
311static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb,
312 enum at91_mb_mode mode)
313{
314 set_mb_mode_prio(priv, mb, mode, 0);
315}
316
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100317static inline u32 at91_can_id_to_reg_mid(canid_t can_id)
318{
319 u32 reg_mid;
320
321 if (can_id & CAN_EFF_FLAG)
322 reg_mid = (can_id & CAN_EFF_MASK) | AT91_MID_MIDE;
323 else
324 reg_mid = (can_id & CAN_SFF_MASK) << 18;
325
326 return reg_mid;
327}
328
David S. Miller99c4a632009-09-25 12:14:43 -0700329/*
330 * Swtich transceiver on or off
331 */
332static void at91_transceiver_switch(const struct at91_priv *priv, int on)
333{
334 if (priv->pdata && priv->pdata->transceiver_switch)
335 priv->pdata->transceiver_switch(on);
336}
337
338static void at91_setup_mailboxes(struct net_device *dev)
339{
340 struct at91_priv *priv = netdev_priv(dev);
341 unsigned int i;
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100342 u32 reg_mid;
David S. Miller99c4a632009-09-25 12:14:43 -0700343
344 /*
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100345 * Due to a chip bug (errata 50.2.6.3 & 50.3.5.3) the first
346 * mailbox is disabled. The next 11 mailboxes are used as a
347 * reception FIFO. The last mailbox is configured with
348 * overwrite option. The overwrite flag indicates a FIFO
349 * overflow.
David S. Miller99c4a632009-09-25 12:14:43 -0700350 */
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100351 reg_mid = at91_can_id_to_reg_mid(priv->mb0_id);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200352 for (i = 0; i < get_mb_rx_first(priv); i++) {
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100353 set_mb_mode(priv, i, AT91_MB_MODE_DISABLED);
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100354 at91_write(priv, AT91_MID(i), reg_mid);
355 at91_write(priv, AT91_MCR(i), 0x0); /* clear dlc */
356 }
357
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200358 for (i = get_mb_rx_first(priv); i < get_mb_rx_last(priv); i++)
David S. Miller99c4a632009-09-25 12:14:43 -0700359 set_mb_mode(priv, i, AT91_MB_MODE_RX);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200360 set_mb_mode(priv, get_mb_rx_last(priv), AT91_MB_MODE_RX_OVRWR);
David S. Miller99c4a632009-09-25 12:14:43 -0700361
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000362 /* reset acceptance mask and id register */
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200363 for (i = get_mb_rx_first(priv); i <= get_mb_rx_last(priv); i++) {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +0100364 at91_write(priv, AT91_MAM(i), 0x0);
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000365 at91_write(priv, AT91_MID(i), AT91_MID_MIDE);
366 }
367
David S. Miller99c4a632009-09-25 12:14:43 -0700368 /* The last 4 mailboxes are used for transmitting. */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200369 for (i = get_mb_tx_first(priv); i <= get_mb_tx_last(priv); i++)
David S. Miller99c4a632009-09-25 12:14:43 -0700370 set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);
371
372 /* Reset tx and rx helper pointers */
Marc Kleine-Budde0909c1e2011-01-06 09:58:42 +0100373 priv->tx_next = priv->tx_echo = 0;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200374 priv->rx_next = get_mb_rx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700375}
376
377static int at91_set_bittiming(struct net_device *dev)
378{
379 const struct at91_priv *priv = netdev_priv(dev);
380 const struct can_bittiming *bt = &priv->can.bittiming;
381 u32 reg_br;
382
Marc Kleine-Buddedbe91322010-10-21 01:01:13 +0000383 reg_br = ((priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) ? 1 << 24 : 0) |
384 ((bt->brp - 1) << 16) | ((bt->sjw - 1) << 12) |
David S. Miller99c4a632009-09-25 12:14:43 -0700385 ((bt->prop_seg - 1) << 8) | ((bt->phase_seg1 - 1) << 4) |
386 ((bt->phase_seg2 - 1) << 0);
387
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000388 netdev_info(dev, "writing AT91_BR: 0x%08x\n", reg_br);
David S. Miller99c4a632009-09-25 12:14:43 -0700389
390 at91_write(priv, AT91_BR, reg_br);
391
392 return 0;
393}
394
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000395static int at91_get_berr_counter(const struct net_device *dev,
396 struct can_berr_counter *bec)
397{
398 const struct at91_priv *priv = netdev_priv(dev);
399 u32 reg_ecr = at91_read(priv, AT91_ECR);
400
401 bec->rxerr = reg_ecr & 0xff;
402 bec->txerr = reg_ecr >> 16;
403
404 return 0;
405}
406
David S. Miller99c4a632009-09-25 12:14:43 -0700407static void at91_chip_start(struct net_device *dev)
408{
409 struct at91_priv *priv = netdev_priv(dev);
410 u32 reg_mr, reg_ier;
411
412 /* disable interrupts */
413 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
414
415 /* disable chip */
416 reg_mr = at91_read(priv, AT91_MR);
417 at91_write(priv, AT91_MR, reg_mr & ~AT91_MR_CANEN);
418
Marc Kleine-Buddeb156fd02010-10-21 01:01:19 +0000419 at91_set_bittiming(dev);
David S. Miller99c4a632009-09-25 12:14:43 -0700420 at91_setup_mailboxes(dev);
421 at91_transceiver_switch(priv, 1);
422
423 /* enable chip */
424 at91_write(priv, AT91_MR, AT91_MR_CANEN);
425
426 priv->can.state = CAN_STATE_ERROR_ACTIVE;
427
428 /* Enable interrupts */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200429 reg_ier = get_irq_mb_rx(priv) | AT91_IRQ_ERRP | AT91_IRQ_ERR_FRAME;
David S. Miller99c4a632009-09-25 12:14:43 -0700430 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
431 at91_write(priv, AT91_IER, reg_ier);
432}
433
434static void at91_chip_stop(struct net_device *dev, enum can_state state)
435{
436 struct at91_priv *priv = netdev_priv(dev);
437 u32 reg_mr;
438
439 /* disable interrupts */
440 at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
441
442 reg_mr = at91_read(priv, AT91_MR);
443 at91_write(priv, AT91_MR, reg_mr & ~AT91_MR_CANEN);
444
445 at91_transceiver_switch(priv, 0);
446 priv->can.state = state;
447}
448
449/*
450 * theory of operation:
451 *
452 * According to the datasheet priority 0 is the highest priority, 15
453 * is the lowest. If two mailboxes have the same priority level the
454 * message of the mailbox with the lowest number is sent first.
455 *
456 * We use the first TX mailbox (AT91_MB_TX_FIRST) with prio 0, then
457 * the next mailbox with prio 0, and so on, until all mailboxes are
458 * used. Then we start from the beginning with mailbox
459 * AT91_MB_TX_FIRST, but with prio 1, mailbox AT91_MB_TX_FIRST + 1
460 * prio 1. When we reach the last mailbox with prio 15, we have to
461 * stop sending, waiting for all messages to be delivered, then start
462 * again with mailbox AT91_MB_TX_FIRST prio 0.
463 *
464 * We use the priv->tx_next as counter for the next transmission
465 * mailbox, but without the offset AT91_MB_TX_FIRST. The lower bits
466 * encode the mailbox number, the upper 4 bits the mailbox priority:
467 *
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200468 * priv->tx_next = (prio << get_next_prio_shift(priv)) |
469 * (mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700470 *
471 */
472static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
473{
474 struct at91_priv *priv = netdev_priv(dev);
475 struct net_device_stats *stats = &dev->stats;
476 struct can_frame *cf = (struct can_frame *)skb->data;
477 unsigned int mb, prio;
478 u32 reg_mid, reg_mcr;
479
Oliver Hartkopp3ccd4c62010-01-12 02:00:46 -0800480 if (can_dropped_invalid_skb(dev, skb))
481 return NETDEV_TX_OK;
482
David S. Miller99c4a632009-09-25 12:14:43 -0700483 mb = get_tx_next_mb(priv);
484 prio = get_tx_next_prio(priv);
485
486 if (unlikely(!(at91_read(priv, AT91_MSR(mb)) & AT91_MSR_MRDY))) {
487 netif_stop_queue(dev);
488
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000489 netdev_err(dev, "BUG! TX buffer full when queue awake!\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700490 return NETDEV_TX_BUSY;
491 }
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +0100492 reg_mid = at91_can_id_to_reg_mid(cf->can_id);
David S. Miller99c4a632009-09-25 12:14:43 -0700493 reg_mcr = ((cf->can_id & CAN_RTR_FLAG) ? AT91_MCR_MRTR : 0) |
494 (cf->can_dlc << 16) | AT91_MCR_MTCR;
495
496 /* disable MB while writing ID (see datasheet) */
497 set_mb_mode(priv, mb, AT91_MB_MODE_DISABLED);
498 at91_write(priv, AT91_MID(mb), reg_mid);
499 set_mb_mode_prio(priv, mb, AT91_MB_MODE_TX, prio);
500
501 at91_write(priv, AT91_MDL(mb), *(u32 *)(cf->data + 0));
502 at91_write(priv, AT91_MDH(mb), *(u32 *)(cf->data + 4));
503
504 /* This triggers transmission */
505 at91_write(priv, AT91_MCR(mb), reg_mcr);
506
507 stats->tx_bytes += cf->can_dlc;
David S. Miller99c4a632009-09-25 12:14:43 -0700508
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300509 /* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200510 can_put_echo_skb(skb, dev, mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700511
512 /*
513 * we have to stop the queue and deliver all messages in case
514 * of a prio+mb counter wrap around. This is the case if
515 * tx_next buffer prio and mailbox equals 0.
516 *
517 * also stop the queue if next buffer is still in use
518 * (== not ready)
519 */
520 priv->tx_next++;
521 if (!(at91_read(priv, AT91_MSR(get_tx_next_mb(priv))) &
522 AT91_MSR_MRDY) ||
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200523 (priv->tx_next & get_next_mask(priv)) == 0)
David S. Miller99c4a632009-09-25 12:14:43 -0700524 netif_stop_queue(dev);
525
526 /* Enable interrupt for this mailbox */
527 at91_write(priv, AT91_IER, 1 << mb);
528
529 return NETDEV_TX_OK;
530}
531
532/**
533 * at91_activate_rx_low - activate lower rx mailboxes
534 * @priv: a91 context
535 *
536 * Reenables the lower mailboxes for reception of new CAN messages
537 */
538static inline void at91_activate_rx_low(const struct at91_priv *priv)
539{
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200540 u32 mask = get_mb_rx_low_mask(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700541 at91_write(priv, AT91_TCR, mask);
542}
543
544/**
545 * at91_activate_rx_mb - reactive single rx mailbox
546 * @priv: a91 context
547 * @mb: mailbox to reactivate
548 *
549 * Reenables given mailbox for reception of new CAN messages
550 */
551static inline void at91_activate_rx_mb(const struct at91_priv *priv,
552 unsigned int mb)
553{
554 u32 mask = 1 << mb;
555 at91_write(priv, AT91_TCR, mask);
556}
557
558/**
559 * at91_rx_overflow_err - send error frame due to rx overflow
560 * @dev: net device
561 */
562static void at91_rx_overflow_err(struct net_device *dev)
563{
564 struct net_device_stats *stats = &dev->stats;
565 struct sk_buff *skb;
566 struct can_frame *cf;
567
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000568 netdev_dbg(dev, "RX buffer overflow\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700569 stats->rx_over_errors++;
570 stats->rx_errors++;
571
572 skb = alloc_can_err_skb(dev, &cf);
573 if (unlikely(!skb))
574 return;
575
576 cf->can_id |= CAN_ERR_CRTL;
577 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
578 netif_receive_skb(skb);
579
580 stats->rx_packets++;
581 stats->rx_bytes += cf->can_dlc;
582}
583
584/**
585 * at91_read_mb - read CAN msg from mailbox (lowlevel impl)
586 * @dev: net device
587 * @mb: mailbox number to read from
588 * @cf: can frame where to store message
589 *
590 * Reads a CAN message from the given mailbox and stores data into
591 * given can frame. "mb" and "cf" must be valid.
592 */
593static void at91_read_mb(struct net_device *dev, unsigned int mb,
594 struct can_frame *cf)
595{
596 const struct at91_priv *priv = netdev_priv(dev);
597 u32 reg_msr, reg_mid;
598
599 reg_mid = at91_read(priv, AT91_MID(mb));
600 if (reg_mid & AT91_MID_MIDE)
601 cf->can_id = ((reg_mid >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
602 else
603 cf->can_id = (reg_mid >> 18) & CAN_SFF_MASK;
604
605 reg_msr = at91_read(priv, AT91_MSR(mb));
Oliver Hartkoppc7cd6062009-12-12 04:13:21 +0000606 cf->can_dlc = get_can_dlc((reg_msr >> 16) & 0xf);
David S. Miller99c4a632009-09-25 12:14:43 -0700607
Marc Kleine-Buddee14ee402010-10-21 18:39:26 +0200608 if (reg_msr & AT91_MSR_MRTR)
609 cf->can_id |= CAN_RTR_FLAG;
610 else {
611 *(u32 *)(cf->data + 0) = at91_read(priv, AT91_MDL(mb));
612 *(u32 *)(cf->data + 4) = at91_read(priv, AT91_MDH(mb));
613 }
David S. Miller99c4a632009-09-25 12:14:43 -0700614
Marc Kleine-Budde8a0e0a42010-10-21 01:01:14 +0000615 /* allow RX of extended frames */
616 at91_write(priv, AT91_MID(mb), AT91_MID_MIDE);
617
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200618 if (unlikely(mb == get_mb_rx_last(priv) && reg_msr & AT91_MSR_MMI))
David S. Miller99c4a632009-09-25 12:14:43 -0700619 at91_rx_overflow_err(dev);
620}
621
622/**
623 * at91_read_msg - read CAN message from mailbox
624 * @dev: net device
625 * @mb: mail box to read from
626 *
627 * Reads a CAN message from given mailbox, and put into linux network
628 * RX queue, does all housekeeping chores (stats, ...)
629 */
630static void at91_read_msg(struct net_device *dev, unsigned int mb)
631{
632 struct net_device_stats *stats = &dev->stats;
633 struct can_frame *cf;
634 struct sk_buff *skb;
635
636 skb = alloc_can_skb(dev, &cf);
637 if (unlikely(!skb)) {
638 stats->rx_dropped++;
639 return;
640 }
641
642 at91_read_mb(dev, mb, cf);
643 netif_receive_skb(skb);
644
645 stats->rx_packets++;
646 stats->rx_bytes += cf->can_dlc;
Fabio Baltieri4723f2b2012-12-18 18:50:59 +0100647
648 can_led_event(dev, CAN_LED_EVENT_RX);
David S. Miller99c4a632009-09-25 12:14:43 -0700649}
650
651/**
652 * at91_poll_rx - read multiple CAN messages from mailboxes
653 * @dev: net device
654 * @quota: max number of pkgs we're allowed to receive
655 *
656 * Theory of Operation:
657 *
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200658 * About 3/4 of the mailboxes (get_mb_rx_first()...get_mb_rx_last())
659 * on the chip are reserved for RX. We split them into 2 groups. The
660 * lower group ranges from get_mb_rx_first() to get_mb_rx_low_last().
David S. Miller99c4a632009-09-25 12:14:43 -0700661 *
662 * Like it or not, but the chip always saves a received CAN message
663 * into the first free mailbox it finds (starting with the
664 * lowest). This makes it very difficult to read the messages in the
665 * right order from the chip. This is how we work around that problem:
666 *
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100667 * The first message goes into mb nr. 1 and issues an interrupt. All
David S. Miller99c4a632009-09-25 12:14:43 -0700668 * rx ints are disabled in the interrupt handler and a napi poll is
669 * scheduled. We read the mailbox, but do _not_ reenable the mb (to
670 * receive another message).
671 *
672 * lower mbxs upper
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100673 * ____^______ __^__
674 * / \ / \
David S. Miller99c4a632009-09-25 12:14:43 -0700675 * +-+-+-+-+-+-+-+-++-+-+-+-+
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100676 * | |x|x|x|x|x|x|x|| | | | |
David S. Miller99c4a632009-09-25 12:14:43 -0700677 * +-+-+-+-+-+-+-+-++-+-+-+-+
678 * 0 0 0 0 0 0 0 0 0 0 1 1 \ mail
679 * 0 1 2 3 4 5 6 7 8 9 0 1 / box
Marc Kleine-Budde9e0a2d12011-01-09 22:46:25 +0100680 * ^
681 * |
682 * \
683 * unused, due to chip bug
David S. Miller99c4a632009-09-25 12:14:43 -0700684 *
685 * The variable priv->rx_next points to the next mailbox to read a
686 * message from. As long we're in the lower mailboxes we just read the
687 * mailbox but not reenable it.
688 *
689 * With completion of the last of the lower mailboxes, we reenable the
690 * whole first group, but continue to look for filled mailboxes in the
691 * upper mailboxes. Imagine the second group like overflow mailboxes,
692 * which takes CAN messages if the lower goup is full. While in the
693 * upper group we reenable the mailbox right after reading it. Giving
694 * the chip more room to store messages.
695 *
696 * After finishing we look again in the lower group if we've still
697 * quota.
698 *
699 */
700static int at91_poll_rx(struct net_device *dev, int quota)
701{
702 struct at91_priv *priv = netdev_priv(dev);
703 u32 reg_sr = at91_read(priv, AT91_SR);
704 const unsigned long *addr = (unsigned long *)&reg_sr;
705 unsigned int mb;
706 int received = 0;
707
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200708 if (priv->rx_next > get_mb_rx_low_last(priv) &&
709 reg_sr & get_mb_rx_low_mask(priv))
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000710 netdev_info(dev,
711 "order of incoming frames cannot be guaranteed\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700712
713 again:
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200714 for (mb = find_next_bit(addr, get_mb_tx_first(priv), priv->rx_next);
715 mb < get_mb_tx_first(priv) && quota > 0;
David S. Miller99c4a632009-09-25 12:14:43 -0700716 reg_sr = at91_read(priv, AT91_SR),
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200717 mb = find_next_bit(addr, get_mb_tx_first(priv), ++priv->rx_next)) {
David S. Miller99c4a632009-09-25 12:14:43 -0700718 at91_read_msg(dev, mb);
719
720 /* reactivate mailboxes */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200721 if (mb == get_mb_rx_low_last(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700722 /* all lower mailboxed, if just finished it */
723 at91_activate_rx_low(priv);
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200724 else if (mb > get_mb_rx_low_last(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700725 /* only the mailbox we read */
726 at91_activate_rx_mb(priv, mb);
727
728 received++;
729 quota--;
730 }
731
732 /* upper group completed, look again in lower */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200733 if (priv->rx_next > get_mb_rx_low_last(priv) &&
Marc Kleine-Budded3d47262011-05-03 17:41:09 +0200734 quota > 0 && mb > get_mb_rx_last(priv)) {
735 priv->rx_next = get_mb_rx_first(priv);
David S. Miller99c4a632009-09-25 12:14:43 -0700736 goto again;
737 }
738
739 return received;
740}
741
742static void at91_poll_err_frame(struct net_device *dev,
743 struct can_frame *cf, u32 reg_sr)
744{
745 struct at91_priv *priv = netdev_priv(dev);
746
747 /* CRC error */
748 if (reg_sr & AT91_IRQ_CERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000749 netdev_dbg(dev, "CERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700750 dev->stats.rx_errors++;
751 priv->can.can_stats.bus_error++;
752 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
753 }
754
755 /* Stuffing Error */
756 if (reg_sr & AT91_IRQ_SERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000757 netdev_dbg(dev, "SERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700758 dev->stats.rx_errors++;
759 priv->can.can_stats.bus_error++;
760 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
761 cf->data[2] |= CAN_ERR_PROT_STUFF;
762 }
763
764 /* Acknowledgement Error */
765 if (reg_sr & AT91_IRQ_AERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000766 netdev_dbg(dev, "AERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700767 dev->stats.tx_errors++;
768 cf->can_id |= CAN_ERR_ACK;
769 }
770
771 /* Form error */
772 if (reg_sr & AT91_IRQ_FERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000773 netdev_dbg(dev, "FERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700774 dev->stats.rx_errors++;
775 priv->can.can_stats.bus_error++;
776 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
777 cf->data[2] |= CAN_ERR_PROT_FORM;
778 }
779
780 /* Bit Error */
781 if (reg_sr & AT91_IRQ_BERR) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000782 netdev_dbg(dev, "BERR irq\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700783 dev->stats.tx_errors++;
784 priv->can.can_stats.bus_error++;
785 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
786 cf->data[2] |= CAN_ERR_PROT_BIT;
787 }
788}
789
790static int at91_poll_err(struct net_device *dev, int quota, u32 reg_sr)
791{
792 struct sk_buff *skb;
793 struct can_frame *cf;
794
795 if (quota == 0)
796 return 0;
797
798 skb = alloc_can_err_skb(dev, &cf);
799 if (unlikely(!skb))
800 return 0;
801
802 at91_poll_err_frame(dev, cf, reg_sr);
803 netif_receive_skb(skb);
804
David S. Miller99c4a632009-09-25 12:14:43 -0700805 dev->stats.rx_packets++;
806 dev->stats.rx_bytes += cf->can_dlc;
807
808 return 1;
809}
810
811static int at91_poll(struct napi_struct *napi, int quota)
812{
813 struct net_device *dev = napi->dev;
814 const struct at91_priv *priv = netdev_priv(dev);
815 u32 reg_sr = at91_read(priv, AT91_SR);
816 int work_done = 0;
817
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200818 if (reg_sr & get_irq_mb_rx(priv))
David S. Miller99c4a632009-09-25 12:14:43 -0700819 work_done += at91_poll_rx(dev, quota - work_done);
820
821 /*
822 * The error bits are clear on read,
823 * so use saved value from irq handler.
824 */
825 reg_sr |= priv->reg_sr;
826 if (reg_sr & AT91_IRQ_ERR_FRAME)
827 work_done += at91_poll_err(dev, quota - work_done, reg_sr);
828
829 if (work_done < quota) {
830 /* enable IRQs for frame errors and all mailboxes >= rx_next */
831 u32 reg_ier = AT91_IRQ_ERR_FRAME;
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200832 reg_ier |= get_irq_mb_rx(priv) & ~AT91_MB_MASK(priv->rx_next);
David S. Miller99c4a632009-09-25 12:14:43 -0700833
834 napi_complete(napi);
835 at91_write(priv, AT91_IER, reg_ier);
836 }
837
838 return work_done;
839}
840
841/*
842 * theory of operation:
843 *
844 * priv->tx_echo holds the number of the oldest can_frame put for
845 * transmission into the hardware, but not yet ACKed by the CAN tx
846 * complete IRQ.
847 *
848 * We iterate from priv->tx_echo to priv->tx_next and check if the
849 * packet has been transmitted, echo it back to the CAN framework. If
850 * we discover a not yet transmitted package, stop looking for more.
851 *
852 */
853static void at91_irq_tx(struct net_device *dev, u32 reg_sr)
854{
855 struct at91_priv *priv = netdev_priv(dev);
856 u32 reg_msr;
857 unsigned int mb;
858
859 /* masking of reg_sr not needed, already done by at91_irq */
860
861 for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
862 mb = get_tx_echo_mb(priv);
863
864 /* no event in mailbox? */
865 if (!(reg_sr & (1 << mb)))
866 break;
867
868 /* Disable irq for this TX mailbox */
869 at91_write(priv, AT91_IDR, 1 << mb);
870
871 /*
872 * only echo if mailbox signals us a transfer
873 * complete (MSR_MRDY). Otherwise it's a tansfer
874 * abort. "can_bus_off()" takes care about the skbs
875 * parked in the echo queue.
876 */
877 reg_msr = at91_read(priv, AT91_MSR(mb));
878 if (likely(reg_msr & AT91_MSR_MRDY &&
879 ~reg_msr & AT91_MSR_MABT)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300880 /* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200881 can_get_echo_skb(dev, mb - get_mb_tx_first(priv));
David S. Miller99c4a632009-09-25 12:14:43 -0700882 dev->stats.tx_packets++;
Fabio Baltieri4723f2b2012-12-18 18:50:59 +0100883 can_led_event(dev, CAN_LED_EVENT_TX);
David S. Miller99c4a632009-09-25 12:14:43 -0700884 }
885 }
886
887 /*
888 * restart queue if we don't have a wrap around but restart if
889 * we get a TX int for the last can frame directly before a
890 * wrap around.
891 */
Marc Kleine-Budde79008992011-05-03 17:31:40 +0200892 if ((priv->tx_next & get_next_mask(priv)) != 0 ||
893 (priv->tx_echo & get_next_mask(priv)) == 0)
David S. Miller99c4a632009-09-25 12:14:43 -0700894 netif_wake_queue(dev);
895}
896
897static void at91_irq_err_state(struct net_device *dev,
898 struct can_frame *cf, enum can_state new_state)
899{
900 struct at91_priv *priv = netdev_priv(dev);
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000901 u32 reg_idr = 0, reg_ier = 0;
902 struct can_berr_counter bec;
David S. Miller99c4a632009-09-25 12:14:43 -0700903
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000904 at91_get_berr_counter(dev, &bec);
David S. Miller99c4a632009-09-25 12:14:43 -0700905
906 switch (priv->can.state) {
907 case CAN_STATE_ERROR_ACTIVE:
908 /*
909 * from: ERROR_ACTIVE
910 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
911 * => : there was a warning int
912 */
913 if (new_state >= CAN_STATE_ERROR_WARNING &&
914 new_state <= CAN_STATE_BUS_OFF) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000915 netdev_dbg(dev, "Error Warning IRQ\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700916 priv->can.can_stats.error_warning++;
917
918 cf->can_id |= CAN_ERR_CRTL;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000919 cf->data[1] = (bec.txerr > bec.rxerr) ?
David S. Miller99c4a632009-09-25 12:14:43 -0700920 CAN_ERR_CRTL_TX_WARNING :
921 CAN_ERR_CRTL_RX_WARNING;
922 }
923 case CAN_STATE_ERROR_WARNING: /* fallthrough */
924 /*
925 * from: ERROR_ACTIVE, ERROR_WARNING
926 * to : ERROR_PASSIVE, BUS_OFF
927 * => : error passive int
928 */
929 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
930 new_state <= CAN_STATE_BUS_OFF) {
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000931 netdev_dbg(dev, "Error Passive IRQ\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700932 priv->can.can_stats.error_passive++;
933
934 cf->can_id |= CAN_ERR_CRTL;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +0000935 cf->data[1] = (bec.txerr > bec.rxerr) ?
David S. Miller99c4a632009-09-25 12:14:43 -0700936 CAN_ERR_CRTL_TX_PASSIVE :
937 CAN_ERR_CRTL_RX_PASSIVE;
938 }
939 break;
940 case CAN_STATE_BUS_OFF:
941 /*
942 * from: BUS_OFF
943 * to : ERROR_ACTIVE, ERROR_WARNING, ERROR_PASSIVE
944 */
945 if (new_state <= CAN_STATE_ERROR_PASSIVE) {
946 cf->can_id |= CAN_ERR_RESTARTED;
947
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000948 netdev_dbg(dev, "restarted\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700949 priv->can.can_stats.restarts++;
950
951 netif_carrier_on(dev);
952 netif_wake_queue(dev);
953 }
954 break;
955 default:
956 break;
957 }
958
959
960 /* process state changes depending on the new state */
961 switch (new_state) {
962 case CAN_STATE_ERROR_ACTIVE:
963 /*
964 * actually we want to enable AT91_IRQ_WARN here, but
965 * it screws up the system under certain
966 * circumstances. so just enable AT91_IRQ_ERRP, thus
967 * the "fallthrough"
968 */
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000969 netdev_dbg(dev, "Error Active\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700970 cf->can_id |= CAN_ERR_PROT;
971 cf->data[2] = CAN_ERR_PROT_ACTIVE;
972 case CAN_STATE_ERROR_WARNING: /* fallthrough */
973 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_BOFF;
974 reg_ier = AT91_IRQ_ERRP;
975 break;
976 case CAN_STATE_ERROR_PASSIVE:
977 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_ERRP;
978 reg_ier = AT91_IRQ_BOFF;
979 break;
980 case CAN_STATE_BUS_OFF:
981 reg_idr = AT91_IRQ_ERRA | AT91_IRQ_ERRP |
982 AT91_IRQ_WARN | AT91_IRQ_BOFF;
983 reg_ier = 0;
984
985 cf->can_id |= CAN_ERR_BUSOFF;
986
Marc Kleine-Budde882055c2010-10-21 01:01:21 +0000987 netdev_dbg(dev, "bus-off\n");
David S. Miller99c4a632009-09-25 12:14:43 -0700988 netif_carrier_off(dev);
989 priv->can.can_stats.bus_off++;
990
991 /* turn off chip, if restart is disabled */
992 if (!priv->can.restart_ms) {
993 at91_chip_stop(dev, CAN_STATE_BUS_OFF);
994 return;
995 }
996 break;
997 default:
998 break;
999 }
1000
1001 at91_write(priv, AT91_IDR, reg_idr);
1002 at91_write(priv, AT91_IER, reg_ier);
1003}
1004
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001005static int at91_get_state_by_bec(const struct net_device *dev,
1006 enum can_state *state)
1007{
1008 struct can_berr_counter bec;
1009 int err;
1010
1011 err = at91_get_berr_counter(dev, &bec);
1012 if (err)
1013 return err;
1014
1015 if (bec.txerr < 96 && bec.rxerr < 96)
1016 *state = CAN_STATE_ERROR_ACTIVE;
1017 else if (bec.txerr < 128 && bec.rxerr < 128)
1018 *state = CAN_STATE_ERROR_WARNING;
1019 else if (bec.txerr < 256 && bec.rxerr < 256)
1020 *state = CAN_STATE_ERROR_PASSIVE;
1021 else
1022 *state = CAN_STATE_BUS_OFF;
1023
1024 return 0;
1025}
1026
1027
David S. Miller99c4a632009-09-25 12:14:43 -07001028static void at91_irq_err(struct net_device *dev)
1029{
1030 struct at91_priv *priv = netdev_priv(dev);
1031 struct sk_buff *skb;
1032 struct can_frame *cf;
1033 enum can_state new_state;
1034 u32 reg_sr;
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001035 int err;
David S. Miller99c4a632009-09-25 12:14:43 -07001036
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001037 if (at91_is_sam9263(priv)) {
1038 reg_sr = at91_read(priv, AT91_SR);
David S. Miller99c4a632009-09-25 12:14:43 -07001039
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001040 /* we need to look at the unmasked reg_sr */
1041 if (unlikely(reg_sr & AT91_IRQ_BOFF))
1042 new_state = CAN_STATE_BUS_OFF;
1043 else if (unlikely(reg_sr & AT91_IRQ_ERRP))
1044 new_state = CAN_STATE_ERROR_PASSIVE;
1045 else if (unlikely(reg_sr & AT91_IRQ_WARN))
1046 new_state = CAN_STATE_ERROR_WARNING;
1047 else if (likely(reg_sr & AT91_IRQ_ERRA))
1048 new_state = CAN_STATE_ERROR_ACTIVE;
1049 else {
1050 netdev_err(dev, "BUG! hardware in undefined state\n");
1051 return;
1052 }
1053 } else {
1054 err = at91_get_state_by_bec(dev, &new_state);
1055 if (err)
1056 return;
David S. Miller99c4a632009-09-25 12:14:43 -07001057 }
1058
1059 /* state hasn't changed */
1060 if (likely(new_state == priv->can.state))
1061 return;
1062
1063 skb = alloc_can_err_skb(dev, &cf);
1064 if (unlikely(!skb))
1065 return;
1066
1067 at91_irq_err_state(dev, cf, new_state);
1068 netif_rx(skb);
1069
David S. Miller99c4a632009-09-25 12:14:43 -07001070 dev->stats.rx_packets++;
1071 dev->stats.rx_bytes += cf->can_dlc;
1072
1073 priv->can.state = new_state;
1074}
1075
1076/*
1077 * interrupt handler
1078 */
1079static irqreturn_t at91_irq(int irq, void *dev_id)
1080{
1081 struct net_device *dev = dev_id;
1082 struct at91_priv *priv = netdev_priv(dev);
1083 irqreturn_t handled = IRQ_NONE;
1084 u32 reg_sr, reg_imr;
1085
1086 reg_sr = at91_read(priv, AT91_SR);
1087 reg_imr = at91_read(priv, AT91_IMR);
1088
1089 /* Ignore masked interrupts */
1090 reg_sr &= reg_imr;
1091 if (!reg_sr)
1092 goto exit;
1093
1094 handled = IRQ_HANDLED;
1095
1096 /* Receive or error interrupt? -> napi */
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001097 if (reg_sr & (get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME)) {
David S. Miller99c4a632009-09-25 12:14:43 -07001098 /*
1099 * The error bits are clear on read,
1100 * save for later use.
1101 */
1102 priv->reg_sr = reg_sr;
1103 at91_write(priv, AT91_IDR,
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001104 get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME);
David S. Miller99c4a632009-09-25 12:14:43 -07001105 napi_schedule(&priv->napi);
1106 }
1107
1108 /* Transmission complete interrupt */
Marc Kleine-Budde79008992011-05-03 17:31:40 +02001109 if (reg_sr & get_irq_mb_tx(priv))
David S. Miller99c4a632009-09-25 12:14:43 -07001110 at91_irq_tx(dev, reg_sr);
1111
1112 at91_irq_err(dev);
1113
1114 exit:
1115 return handled;
1116}
1117
1118static int at91_open(struct net_device *dev)
1119{
1120 struct at91_priv *priv = netdev_priv(dev);
1121 int err;
1122
1123 clk_enable(priv->clk);
1124
1125 /* check or determine and set bittime */
1126 err = open_candev(dev);
1127 if (err)
1128 goto out;
1129
1130 /* register interrupt handler */
1131 if (request_irq(dev->irq, at91_irq, IRQF_SHARED,
1132 dev->name, dev)) {
1133 err = -EAGAIN;
1134 goto out_close;
1135 }
1136
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001137 can_led_event(dev, CAN_LED_EVENT_OPEN);
1138
David S. Miller99c4a632009-09-25 12:14:43 -07001139 /* start chip and queuing */
1140 at91_chip_start(dev);
1141 napi_enable(&priv->napi);
1142 netif_start_queue(dev);
1143
1144 return 0;
1145
1146 out_close:
1147 close_candev(dev);
1148 out:
1149 clk_disable(priv->clk);
1150
1151 return err;
1152}
1153
1154/*
1155 * stop CAN bus activity
1156 */
1157static int at91_close(struct net_device *dev)
1158{
1159 struct at91_priv *priv = netdev_priv(dev);
1160
1161 netif_stop_queue(dev);
1162 napi_disable(&priv->napi);
1163 at91_chip_stop(dev, CAN_STATE_STOPPED);
1164
1165 free_irq(dev->irq, dev);
1166 clk_disable(priv->clk);
1167
1168 close_candev(dev);
1169
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001170 can_led_event(dev, CAN_LED_EVENT_STOP);
1171
David S. Miller99c4a632009-09-25 12:14:43 -07001172 return 0;
1173}
1174
1175static int at91_set_mode(struct net_device *dev, enum can_mode mode)
1176{
1177 switch (mode) {
1178 case CAN_MODE_START:
1179 at91_chip_start(dev);
1180 netif_wake_queue(dev);
1181 break;
1182
1183 default:
1184 return -EOPNOTSUPP;
1185 }
1186
1187 return 0;
1188}
1189
1190static const struct net_device_ops at91_netdev_ops = {
1191 .ndo_open = at91_open,
1192 .ndo_stop = at91_close,
1193 .ndo_start_xmit = at91_start_xmit,
1194};
1195
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001196static ssize_t at91_sysfs_show_mb0_id(struct device *dev,
1197 struct device_attribute *attr, char *buf)
1198{
1199 struct at91_priv *priv = netdev_priv(to_net_dev(dev));
1200
1201 if (priv->mb0_id & CAN_EFF_FLAG)
1202 return snprintf(buf, PAGE_SIZE, "0x%08x\n", priv->mb0_id);
1203 else
1204 return snprintf(buf, PAGE_SIZE, "0x%03x\n", priv->mb0_id);
1205}
1206
1207static ssize_t at91_sysfs_set_mb0_id(struct device *dev,
1208 struct device_attribute *attr, const char *buf, size_t count)
1209{
1210 struct net_device *ndev = to_net_dev(dev);
1211 struct at91_priv *priv = netdev_priv(ndev);
1212 unsigned long can_id;
1213 ssize_t ret;
1214 int err;
1215
1216 rtnl_lock();
1217
1218 if (ndev->flags & IFF_UP) {
1219 ret = -EBUSY;
1220 goto out;
1221 }
1222
Jingoo Han0672f0a2013-05-31 21:18:55 +00001223 err = kstrtoul(buf, 0, &can_id);
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001224 if (err) {
1225 ret = err;
1226 goto out;
1227 }
1228
1229 if (can_id & CAN_EFF_FLAG)
1230 can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
1231 else
1232 can_id &= CAN_SFF_MASK;
1233
1234 priv->mb0_id = can_id;
1235 ret = count;
1236
1237 out:
1238 rtnl_unlock();
1239 return ret;
1240}
1241
Vasiliy Kulikovfef52b02011-02-04 02:23:50 +00001242static DEVICE_ATTR(mb0_id, S_IWUSR | S_IRUGO,
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001243 at91_sysfs_show_mb0_id, at91_sysfs_set_mb0_id);
1244
1245static struct attribute *at91_sysfs_attrs[] = {
1246 &dev_attr_mb0_id.attr,
1247 NULL,
1248};
1249
1250static struct attribute_group at91_sysfs_attr_group = {
1251 .attrs = at91_sysfs_attrs,
1252};
1253
Ludovic Desroches3078cde72013-03-11 18:26:03 +01001254#if defined(CONFIG_OF)
1255static const struct of_device_id at91_can_dt_ids[] = {
1256 {
1257 .compatible = "atmel,at91sam9x5-can",
1258 .data = &at91_at91sam9x5_data,
1259 }, {
1260 .compatible = "atmel,at91sam9263-can",
1261 .data = &at91_at91sam9263_data,
1262 }, {
1263 /* sentinel */
1264 }
1265};
1266MODULE_DEVICE_TABLE(of, at91_can_dt_ids);
Ludovic Desroches3078cde72013-03-11 18:26:03 +01001267#endif
1268
1269static const struct at91_devtype_data *at91_can_get_driver_data(struct platform_device *pdev)
1270{
1271 if (pdev->dev.of_node) {
1272 const struct of_device_id *match;
1273
1274 match = of_match_node(at91_can_dt_ids, pdev->dev.of_node);
1275 if (!match) {
1276 dev_err(&pdev->dev, "no matching node found in dtb\n");
1277 return NULL;
1278 }
1279 return (const struct at91_devtype_data *)match->data;
1280 }
1281 return (const struct at91_devtype_data *)
1282 platform_get_device_id(pdev)->driver_data;
1283}
1284
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001285static int at91_can_probe(struct platform_device *pdev)
David S. Miller99c4a632009-09-25 12:14:43 -07001286{
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001287 const struct at91_devtype_data *devtype_data;
David S. Miller99c4a632009-09-25 12:14:43 -07001288 struct net_device *dev;
1289 struct at91_priv *priv;
1290 struct resource *res;
1291 struct clk *clk;
1292 void __iomem *addr;
1293 int err, irq;
1294
Ludovic Desroches3078cde72013-03-11 18:26:03 +01001295 devtype_data = at91_can_get_driver_data(pdev);
1296 if (!devtype_data) {
1297 dev_err(&pdev->dev, "no driver data\n");
1298 err = -ENODEV;
1299 goto exit;
1300 }
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001301
David S. Miller99c4a632009-09-25 12:14:43 -07001302 clk = clk_get(&pdev->dev, "can_clk");
1303 if (IS_ERR(clk)) {
1304 dev_err(&pdev->dev, "no clock defined\n");
1305 err = -ENODEV;
1306 goto exit;
1307 }
1308
1309 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1310 irq = platform_get_irq(pdev, 0);
Uwe Kleine-König4773a472009-12-18 20:31:56 -08001311 if (!res || irq <= 0) {
David S. Miller99c4a632009-09-25 12:14:43 -07001312 err = -ENODEV;
1313 goto exit_put;
1314 }
1315
1316 if (!request_mem_region(res->start,
1317 resource_size(res),
1318 pdev->name)) {
1319 err = -EBUSY;
1320 goto exit_put;
1321 }
1322
1323 addr = ioremap_nocache(res->start, resource_size(res));
1324 if (!addr) {
1325 err = -ENOMEM;
1326 goto exit_release;
1327 }
1328
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001329 dev = alloc_candev(sizeof(struct at91_priv),
1330 1 << devtype_data->tx_shift);
David S. Miller99c4a632009-09-25 12:14:43 -07001331 if (!dev) {
1332 err = -ENOMEM;
1333 goto exit_iounmap;
1334 }
1335
1336 dev->netdev_ops = &at91_netdev_ops;
1337 dev->irq = irq;
1338 dev->flags |= IFF_ECHO;
1339
1340 priv = netdev_priv(dev);
1341 priv->can.clock.freq = clk_get_rate(clk);
1342 priv->can.bittiming_const = &at91_bittiming_const;
David S. Miller99c4a632009-09-25 12:14:43 -07001343 priv->can.do_set_mode = at91_set_mode;
Marc Kleine-Budde33a6f292010-10-21 01:01:18 +00001344 priv->can.do_get_berr_counter = at91_get_berr_counter;
Christian Pellegrinad72c342010-01-14 07:08:34 +00001345 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
David S. Miller99c4a632009-09-25 12:14:43 -07001346 priv->dev = dev;
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001347 priv->reg_base = addr;
1348 priv->devtype_data = *devtype_data;
David S. Miller99c4a632009-09-25 12:14:43 -07001349 priv->clk = clk;
Jingoo Han6cbdb912013-09-10 17:40:09 +09001350 priv->pdata = dev_get_platdata(&pdev->dev);
Marc Kleine-Budde3a5655a2011-01-10 20:44:22 +01001351 priv->mb0_id = 0x7ff;
David S. Miller99c4a632009-09-25 12:14:43 -07001352
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001353 netif_napi_add(dev, &priv->napi, at91_poll, get_mb_rx_num(priv));
David S. Miller99c4a632009-09-25 12:14:43 -07001354
Marc Kleine-Budde07a648e2011-06-01 00:20:17 +02001355 if (at91_is_sam9263(priv))
1356 dev->sysfs_groups[0] = &at91_sysfs_attr_group;
1357
Libo Chen40f7e0d2013-08-21 18:15:03 +08001358 platform_set_drvdata(pdev, dev);
David S. Miller99c4a632009-09-25 12:14:43 -07001359 SET_NETDEV_DEV(dev, &pdev->dev);
1360
1361 err = register_candev(dev);
1362 if (err) {
1363 dev_err(&pdev->dev, "registering netdev failed\n");
1364 goto exit_free;
1365 }
1366
Fabio Baltieri4723f2b2012-12-18 18:50:59 +01001367 devm_can_led_init(dev);
1368
David S. Miller99c4a632009-09-25 12:14:43 -07001369 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1370 priv->reg_base, dev->irq);
1371
1372 return 0;
1373
1374 exit_free:
Marc Kleine-Budde759a6c72010-10-21 01:01:15 +00001375 free_candev(dev);
David S. Miller99c4a632009-09-25 12:14:43 -07001376 exit_iounmap:
1377 iounmap(addr);
1378 exit_release:
1379 release_mem_region(res->start, resource_size(res));
1380 exit_put:
1381 clk_put(clk);
1382 exit:
1383 return err;
1384}
1385
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001386static int at91_can_remove(struct platform_device *pdev)
David S. Miller99c4a632009-09-25 12:14:43 -07001387{
1388 struct net_device *dev = platform_get_drvdata(pdev);
1389 struct at91_priv *priv = netdev_priv(dev);
1390 struct resource *res;
1391
1392 unregister_netdev(dev);
1393
David S. Miller99c4a632009-09-25 12:14:43 -07001394 iounmap(priv->reg_base);
1395
1396 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1397 release_mem_region(res->start, resource_size(res));
1398
1399 clk_put(priv->clk);
1400
Marc Kleine-Budde759a6c72010-10-21 01:01:15 +00001401 free_candev(dev);
1402
David S. Miller99c4a632009-09-25 12:14:43 -07001403 return 0;
1404}
1405
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001406static const struct platform_device_id at91_can_id_table[] = {
1407 {
1408 .name = "at91_can",
Ludovic Desroches3078cde72013-03-11 18:26:03 +01001409 .driver_data = (kernel_ulong_t)&at91_at91sam9x5_data,
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001410 }, {
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001411 .name = "at91sam9x5_can",
Ludovic Desroches3078cde72013-03-11 18:26:03 +01001412 .driver_data = (kernel_ulong_t)&at91_at91sam9263_data,
Marc Kleine-Budde6388b392011-04-17 00:08:45 +02001413 }, {
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001414 /* sentinel */
1415 }
1416};
Marc Kleine-Budde09ca71c2012-10-12 09:44:51 +02001417MODULE_DEVICE_TABLE(platform, at91_can_id_table);
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001418
David S. Miller99c4a632009-09-25 12:14:43 -07001419static struct platform_driver at91_can_driver = {
Marc Kleine-Budde44d85662011-01-30 22:14:49 +01001420 .probe = at91_can_probe,
Bill Pemberton3c8ac0f2012-12-03 09:22:44 -05001421 .remove = at91_can_remove,
Marc Kleine-Budde44d85662011-01-30 22:14:49 +01001422 .driver = {
1423 .name = KBUILD_MODNAME,
1424 .owner = THIS_MODULE,
Sachin Kamat1f3e4b02013-06-12 17:00:39 +05301425 .of_match_table = of_match_ptr(at91_can_dt_ids),
David S. Miller99c4a632009-09-25 12:14:43 -07001426 },
Marc Kleine-Budded3d47262011-05-03 17:41:09 +02001427 .id_table = at91_can_id_table,
David S. Miller99c4a632009-09-25 12:14:43 -07001428};
1429
Axel Lin871d3372011-11-27 15:42:31 +00001430module_platform_driver(at91_can_driver);
David S. Miller99c4a632009-09-25 12:14:43 -07001431
1432MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
1433MODULE_LICENSE("GPL v2");
Marc Kleine-Budde00389b02010-10-21 01:01:22 +00001434MODULE_DESCRIPTION(KBUILD_MODNAME " CAN netdevice driver");