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881ff67a BS |
1 | /* |
2 | * CAN bus driver for Bosch C_CAN controller | |
3 | * | |
4 | * Copyright (C) 2010 ST Microelectronics | |
5 | * Bhupesh Sharma <bhupesh.sharma@st.com> | |
6 | * | |
7 | * Borrowed heavily from the C_CAN driver originally written by: | |
8 | * Copyright (C) 2007 | |
9 | * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de> | |
10 | * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch> | |
11 | * | |
12 | * TX and RX NAPI implementation has been borrowed from at91 CAN driver | |
13 | * written by: | |
14 | * Copyright | |
15 | * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de> | |
16 | * (C) 2008, 2009 by Marc Kleine-Budde <kernel@pengutronix.de> | |
17 | * | |
18 | * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B. | |
19 | * Bosch C_CAN user manual can be obtained from: | |
20 | * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/ | |
21 | * users_manual_c_can.pdf | |
22 | * | |
23 | * This file is licensed under the terms of the GNU General Public | |
24 | * License version 2. This program is licensed "as is" without any | |
25 | * warranty of any kind, whether express or implied. | |
26 | */ | |
27 | ||
28 | #include <linux/kernel.h> | |
29 | #include <linux/version.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/interrupt.h> | |
32 | #include <linux/delay.h> | |
33 | #include <linux/netdevice.h> | |
34 | #include <linux/if_arp.h> | |
35 | #include <linux/if_ether.h> | |
36 | #include <linux/list.h> | |
37 | #include <linux/delay.h> | |
38 | #include <linux/io.h> | |
39 | ||
40 | #include <linux/can.h> | |
41 | #include <linux/can/dev.h> | |
42 | #include <linux/can/error.h> | |
43 | ||
44 | #include "c_can.h" | |
45 | ||
46 | /* control register */ | |
47 | #define CONTROL_TEST BIT(7) | |
48 | #define CONTROL_CCE BIT(6) | |
49 | #define CONTROL_DISABLE_AR BIT(5) | |
50 | #define CONTROL_ENABLE_AR (0 << 5) | |
51 | #define CONTROL_EIE BIT(3) | |
52 | #define CONTROL_SIE BIT(2) | |
53 | #define CONTROL_IE BIT(1) | |
54 | #define CONTROL_INIT BIT(0) | |
55 | ||
56 | /* test register */ | |
57 | #define TEST_RX BIT(7) | |
58 | #define TEST_TX1 BIT(6) | |
59 | #define TEST_TX2 BIT(5) | |
60 | #define TEST_LBACK BIT(4) | |
61 | #define TEST_SILENT BIT(3) | |
62 | #define TEST_BASIC BIT(2) | |
63 | ||
64 | /* status register */ | |
65 | #define STATUS_BOFF BIT(7) | |
66 | #define STATUS_EWARN BIT(6) | |
67 | #define STATUS_EPASS BIT(5) | |
68 | #define STATUS_RXOK BIT(4) | |
69 | #define STATUS_TXOK BIT(3) | |
70 | ||
71 | /* error counter register */ | |
72 | #define ERR_CNT_TEC_MASK 0xff | |
73 | #define ERR_CNT_TEC_SHIFT 0 | |
74 | #define ERR_CNT_REC_SHIFT 8 | |
75 | #define ERR_CNT_REC_MASK (0x7f << ERR_CNT_REC_SHIFT) | |
76 | #define ERR_CNT_RP_SHIFT 15 | |
77 | #define ERR_CNT_RP_MASK (0x1 << ERR_CNT_RP_SHIFT) | |
78 | ||
79 | /* bit-timing register */ | |
80 | #define BTR_BRP_MASK 0x3f | |
81 | #define BTR_BRP_SHIFT 0 | |
82 | #define BTR_SJW_SHIFT 6 | |
83 | #define BTR_SJW_MASK (0x3 << BTR_SJW_SHIFT) | |
84 | #define BTR_TSEG1_SHIFT 8 | |
85 | #define BTR_TSEG1_MASK (0xf << BTR_TSEG1_SHIFT) | |
86 | #define BTR_TSEG2_SHIFT 12 | |
87 | #define BTR_TSEG2_MASK (0x7 << BTR_TSEG2_SHIFT) | |
88 | ||
89 | /* brp extension register */ | |
90 | #define BRP_EXT_BRPE_MASK 0x0f | |
91 | #define BRP_EXT_BRPE_SHIFT 0 | |
92 | ||
93 | /* IFx command request */ | |
94 | #define IF_COMR_BUSY BIT(15) | |
95 | ||
96 | /* IFx command mask */ | |
97 | #define IF_COMM_WR BIT(7) | |
98 | #define IF_COMM_MASK BIT(6) | |
99 | #define IF_COMM_ARB BIT(5) | |
100 | #define IF_COMM_CONTROL BIT(4) | |
101 | #define IF_COMM_CLR_INT_PND BIT(3) | |
102 | #define IF_COMM_TXRQST BIT(2) | |
103 | #define IF_COMM_DATAA BIT(1) | |
104 | #define IF_COMM_DATAB BIT(0) | |
105 | #define IF_COMM_ALL (IF_COMM_MASK | IF_COMM_ARB | \ | |
106 | IF_COMM_CONTROL | IF_COMM_TXRQST | \ | |
107 | IF_COMM_DATAA | IF_COMM_DATAB) | |
108 | ||
109 | /* IFx arbitration */ | |
110 | #define IF_ARB_MSGVAL BIT(15) | |
111 | #define IF_ARB_MSGXTD BIT(14) | |
112 | #define IF_ARB_TRANSMIT BIT(13) | |
113 | ||
114 | /* IFx message control */ | |
115 | #define IF_MCONT_NEWDAT BIT(15) | |
116 | #define IF_MCONT_MSGLST BIT(14) | |
117 | #define IF_MCONT_CLR_MSGLST (0 << 14) | |
118 | #define IF_MCONT_INTPND BIT(13) | |
119 | #define IF_MCONT_UMASK BIT(12) | |
120 | #define IF_MCONT_TXIE BIT(11) | |
121 | #define IF_MCONT_RXIE BIT(10) | |
122 | #define IF_MCONT_RMTEN BIT(9) | |
123 | #define IF_MCONT_TXRQST BIT(8) | |
124 | #define IF_MCONT_EOB BIT(7) | |
125 | #define IF_MCONT_DLC_MASK 0xf | |
126 | ||
127 | /* | |
128 | * IFx register masks: | |
129 | * allow easy operation on 16-bit registers when the | |
130 | * argument is 32-bit instead | |
131 | */ | |
132 | #define IFX_WRITE_LOW_16BIT(x) ((x) & 0xFFFF) | |
133 | #define IFX_WRITE_HIGH_16BIT(x) (((x) & 0xFFFF0000) >> 16) | |
134 | ||
135 | /* message object split */ | |
136 | #define C_CAN_NO_OF_OBJECTS 32 | |
137 | #define C_CAN_MSG_OBJ_RX_NUM 16 | |
138 | #define C_CAN_MSG_OBJ_TX_NUM 16 | |
139 | ||
140 | #define C_CAN_MSG_OBJ_RX_FIRST 1 | |
141 | #define C_CAN_MSG_OBJ_RX_LAST (C_CAN_MSG_OBJ_RX_FIRST + \ | |
142 | C_CAN_MSG_OBJ_RX_NUM - 1) | |
143 | ||
144 | #define C_CAN_MSG_OBJ_TX_FIRST (C_CAN_MSG_OBJ_RX_LAST + 1) | |
145 | #define C_CAN_MSG_OBJ_TX_LAST (C_CAN_MSG_OBJ_TX_FIRST + \ | |
146 | C_CAN_MSG_OBJ_TX_NUM - 1) | |
147 | ||
148 | #define C_CAN_MSG_OBJ_RX_SPLIT 9 | |
149 | #define C_CAN_MSG_RX_LOW_LAST (C_CAN_MSG_OBJ_RX_SPLIT - 1) | |
150 | ||
151 | #define C_CAN_NEXT_MSG_OBJ_MASK (C_CAN_MSG_OBJ_TX_NUM - 1) | |
152 | #define RECEIVE_OBJECT_BITS 0x0000ffff | |
153 | ||
154 | /* status interrupt */ | |
155 | #define STATUS_INTERRUPT 0x8000 | |
156 | ||
157 | /* global interrupt masks */ | |
158 | #define ENABLE_ALL_INTERRUPTS 1 | |
159 | #define DISABLE_ALL_INTERRUPTS 0 | |
160 | ||
161 | /* minimum timeout for checking BUSY status */ | |
162 | #define MIN_TIMEOUT_VALUE 6 | |
163 | ||
164 | /* napi related */ | |
165 | #define C_CAN_NAPI_WEIGHT C_CAN_MSG_OBJ_RX_NUM | |
166 | ||
167 | /* c_can lec values */ | |
168 | enum c_can_lec_type { | |
169 | LEC_NO_ERROR = 0, | |
170 | LEC_STUFF_ERROR, | |
171 | LEC_FORM_ERROR, | |
172 | LEC_ACK_ERROR, | |
173 | LEC_BIT1_ERROR, | |
174 | LEC_BIT0_ERROR, | |
175 | LEC_CRC_ERROR, | |
176 | LEC_UNUSED, | |
177 | }; | |
178 | ||
179 | /* | |
180 | * c_can error types: | |
181 | * Bus errors (BUS_OFF, ERROR_WARNING, ERROR_PASSIVE) are supported | |
182 | */ | |
183 | enum c_can_bus_error_types { | |
184 | C_CAN_NO_ERROR = 0, | |
185 | C_CAN_BUS_OFF, | |
186 | C_CAN_ERROR_WARNING, | |
187 | C_CAN_ERROR_PASSIVE, | |
188 | }; | |
189 | ||
190 | static struct can_bittiming_const c_can_bittiming_const = { | |
191 | .name = KBUILD_MODNAME, | |
192 | .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ | |
193 | .tseg1_max = 16, | |
194 | .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ | |
195 | .tseg2_max = 8, | |
196 | .sjw_max = 4, | |
197 | .brp_min = 1, | |
198 | .brp_max = 1024, /* 6-bit BRP field + 4-bit BRPE field*/ | |
199 | .brp_inc = 1, | |
200 | }; | |
201 | ||
202 | static inline int get_tx_next_msg_obj(const struct c_can_priv *priv) | |
203 | { | |
204 | return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) + | |
205 | C_CAN_MSG_OBJ_TX_FIRST; | |
206 | } | |
207 | ||
208 | static inline int get_tx_echo_msg_obj(const struct c_can_priv *priv) | |
209 | { | |
210 | return (priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) + | |
211 | C_CAN_MSG_OBJ_TX_FIRST; | |
212 | } | |
213 | ||
214 | static u32 c_can_read_reg32(struct c_can_priv *priv, void *reg) | |
215 | { | |
216 | u32 val = priv->read_reg(priv, reg); | |
217 | val |= ((u32) priv->read_reg(priv, reg + 2)) << 16; | |
218 | return val; | |
219 | } | |
220 | ||
221 | static void c_can_enable_all_interrupts(struct c_can_priv *priv, | |
222 | int enable) | |
223 | { | |
224 | unsigned int cntrl_save = priv->read_reg(priv, | |
225 | &priv->regs->control); | |
226 | ||
227 | if (enable) | |
228 | cntrl_save |= (CONTROL_SIE | CONTROL_EIE | CONTROL_IE); | |
229 | else | |
230 | cntrl_save &= ~(CONTROL_EIE | CONTROL_IE | CONTROL_SIE); | |
231 | ||
232 | priv->write_reg(priv, &priv->regs->control, cntrl_save); | |
233 | } | |
234 | ||
235 | static inline int c_can_msg_obj_is_busy(struct c_can_priv *priv, int iface) | |
236 | { | |
237 | int count = MIN_TIMEOUT_VALUE; | |
238 | ||
239 | while (count && priv->read_reg(priv, | |
240 | &priv->regs->ifregs[iface].com_req) & | |
241 | IF_COMR_BUSY) { | |
242 | count--; | |
243 | udelay(1); | |
244 | } | |
245 | ||
246 | if (!count) | |
247 | return 1; | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | static inline void c_can_object_get(struct net_device *dev, | |
253 | int iface, int objno, int mask) | |
254 | { | |
255 | struct c_can_priv *priv = netdev_priv(dev); | |
256 | ||
257 | /* | |
258 | * As per specs, after writting the message object number in the | |
259 | * IF command request register the transfer b/w interface | |
260 | * register and message RAM must be complete in 6 CAN-CLK | |
261 | * period. | |
262 | */ | |
263 | priv->write_reg(priv, &priv->regs->ifregs[iface].com_mask, | |
264 | IFX_WRITE_LOW_16BIT(mask)); | |
265 | priv->write_reg(priv, &priv->regs->ifregs[iface].com_req, | |
266 | IFX_WRITE_LOW_16BIT(objno)); | |
267 | ||
268 | if (c_can_msg_obj_is_busy(priv, iface)) | |
269 | netdev_err(dev, "timed out in object get\n"); | |
270 | } | |
271 | ||
272 | static inline void c_can_object_put(struct net_device *dev, | |
273 | int iface, int objno, int mask) | |
274 | { | |
275 | struct c_can_priv *priv = netdev_priv(dev); | |
276 | ||
277 | /* | |
278 | * As per specs, after writting the message object number in the | |
279 | * IF command request register the transfer b/w interface | |
280 | * register and message RAM must be complete in 6 CAN-CLK | |
281 | * period. | |
282 | */ | |
283 | priv->write_reg(priv, &priv->regs->ifregs[iface].com_mask, | |
284 | (IF_COMM_WR | IFX_WRITE_LOW_16BIT(mask))); | |
285 | priv->write_reg(priv, &priv->regs->ifregs[iface].com_req, | |
286 | IFX_WRITE_LOW_16BIT(objno)); | |
287 | ||
288 | if (c_can_msg_obj_is_busy(priv, iface)) | |
289 | netdev_err(dev, "timed out in object put\n"); | |
290 | } | |
291 | ||
292 | static void c_can_write_msg_object(struct net_device *dev, | |
293 | int iface, struct can_frame *frame, int objno) | |
294 | { | |
295 | int i; | |
296 | u16 flags = 0; | |
297 | unsigned int id; | |
298 | struct c_can_priv *priv = netdev_priv(dev); | |
299 | ||
300 | if (!(frame->can_id & CAN_RTR_FLAG)) | |
301 | flags |= IF_ARB_TRANSMIT; | |
302 | ||
303 | if (frame->can_id & CAN_EFF_FLAG) { | |
304 | id = frame->can_id & CAN_EFF_MASK; | |
305 | flags |= IF_ARB_MSGXTD; | |
306 | } else | |
307 | id = ((frame->can_id & CAN_SFF_MASK) << 18); | |
308 | ||
309 | flags |= IF_ARB_MSGVAL; | |
310 | ||
311 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb1, | |
312 | IFX_WRITE_LOW_16BIT(id)); | |
313 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb2, flags | | |
314 | IFX_WRITE_HIGH_16BIT(id)); | |
315 | ||
316 | for (i = 0; i < frame->can_dlc; i += 2) { | |
317 | priv->write_reg(priv, &priv->regs->ifregs[iface].data[i / 2], | |
318 | frame->data[i] | (frame->data[i + 1] << 8)); | |
319 | } | |
320 | ||
321 | /* enable interrupt for this message object */ | |
322 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, | |
323 | IF_MCONT_TXIE | IF_MCONT_TXRQST | IF_MCONT_EOB | | |
324 | frame->can_dlc); | |
325 | c_can_object_put(dev, iface, objno, IF_COMM_ALL); | |
326 | } | |
327 | ||
328 | static inline void c_can_mark_rx_msg_obj(struct net_device *dev, | |
329 | int iface, int ctrl_mask, | |
330 | int obj) | |
331 | { | |
332 | struct c_can_priv *priv = netdev_priv(dev); | |
333 | ||
334 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, | |
335 | ctrl_mask & ~(IF_MCONT_MSGLST | IF_MCONT_INTPND)); | |
336 | c_can_object_put(dev, iface, obj, IF_COMM_CONTROL); | |
337 | ||
338 | } | |
339 | ||
340 | static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev, | |
341 | int iface, | |
342 | int ctrl_mask) | |
343 | { | |
344 | int i; | |
345 | struct c_can_priv *priv = netdev_priv(dev); | |
346 | ||
347 | for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++) { | |
348 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, | |
349 | ctrl_mask & ~(IF_MCONT_MSGLST | | |
350 | IF_MCONT_INTPND | IF_MCONT_NEWDAT)); | |
351 | c_can_object_put(dev, iface, i, IF_COMM_CONTROL); | |
352 | } | |
353 | } | |
354 | ||
355 | static inline void c_can_activate_rx_msg_obj(struct net_device *dev, | |
356 | int iface, int ctrl_mask, | |
357 | int obj) | |
358 | { | |
359 | struct c_can_priv *priv = netdev_priv(dev); | |
360 | ||
361 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, | |
362 | ctrl_mask & ~(IF_MCONT_MSGLST | | |
363 | IF_MCONT_INTPND | IF_MCONT_NEWDAT)); | |
364 | c_can_object_put(dev, iface, obj, IF_COMM_CONTROL); | |
365 | } | |
366 | ||
367 | static void c_can_handle_lost_msg_obj(struct net_device *dev, | |
368 | int iface, int objno) | |
369 | { | |
370 | struct c_can_priv *priv = netdev_priv(dev); | |
371 | struct net_device_stats *stats = &dev->stats; | |
372 | struct sk_buff *skb; | |
373 | struct can_frame *frame; | |
374 | ||
375 | netdev_err(dev, "msg lost in buffer %d\n", objno); | |
376 | ||
377 | c_can_object_get(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST); | |
378 | ||
379 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, | |
380 | IF_MCONT_CLR_MSGLST); | |
381 | ||
382 | c_can_object_put(dev, 0, objno, IF_COMM_CONTROL); | |
383 | ||
384 | /* create an error msg */ | |
385 | skb = alloc_can_err_skb(dev, &frame); | |
386 | if (unlikely(!skb)) | |
387 | return; | |
388 | ||
389 | frame->can_id |= CAN_ERR_CRTL; | |
390 | frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; | |
391 | stats->rx_errors++; | |
392 | stats->rx_over_errors++; | |
393 | ||
394 | netif_receive_skb(skb); | |
395 | } | |
396 | ||
397 | static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl) | |
398 | { | |
399 | u16 flags, data; | |
400 | int i; | |
401 | unsigned int val; | |
402 | struct c_can_priv *priv = netdev_priv(dev); | |
403 | struct net_device_stats *stats = &dev->stats; | |
404 | struct sk_buff *skb; | |
405 | struct can_frame *frame; | |
406 | ||
407 | skb = alloc_can_skb(dev, &frame); | |
408 | if (!skb) { | |
409 | stats->rx_dropped++; | |
410 | return -ENOMEM; | |
411 | } | |
412 | ||
413 | frame->can_dlc = get_can_dlc(ctrl & 0x0F); | |
414 | ||
415 | flags = priv->read_reg(priv, &priv->regs->ifregs[iface].arb2); | |
416 | val = priv->read_reg(priv, &priv->regs->ifregs[iface].arb1) | | |
417 | (flags << 16); | |
418 | ||
419 | if (flags & IF_ARB_MSGXTD) | |
420 | frame->can_id = (val & CAN_EFF_MASK) | CAN_EFF_FLAG; | |
421 | else | |
422 | frame->can_id = (val >> 18) & CAN_SFF_MASK; | |
423 | ||
424 | if (flags & IF_ARB_TRANSMIT) | |
425 | frame->can_id |= CAN_RTR_FLAG; | |
426 | else { | |
427 | for (i = 0; i < frame->can_dlc; i += 2) { | |
428 | data = priv->read_reg(priv, | |
429 | &priv->regs->ifregs[iface].data[i / 2]); | |
430 | frame->data[i] = data; | |
431 | frame->data[i + 1] = data >> 8; | |
432 | } | |
433 | } | |
434 | ||
435 | netif_receive_skb(skb); | |
436 | ||
437 | stats->rx_packets++; | |
438 | stats->rx_bytes += frame->can_dlc; | |
439 | ||
440 | return 0; | |
441 | } | |
442 | ||
443 | static void c_can_setup_receive_object(struct net_device *dev, int iface, | |
444 | int objno, unsigned int mask, | |
445 | unsigned int id, unsigned int mcont) | |
446 | { | |
447 | struct c_can_priv *priv = netdev_priv(dev); | |
448 | ||
449 | priv->write_reg(priv, &priv->regs->ifregs[iface].mask1, | |
450 | IFX_WRITE_LOW_16BIT(mask)); | |
451 | priv->write_reg(priv, &priv->regs->ifregs[iface].mask2, | |
452 | IFX_WRITE_HIGH_16BIT(mask)); | |
453 | ||
454 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb1, | |
455 | IFX_WRITE_LOW_16BIT(id)); | |
456 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb2, | |
457 | (IF_ARB_MSGVAL | IFX_WRITE_HIGH_16BIT(id))); | |
458 | ||
459 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, mcont); | |
460 | c_can_object_put(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST); | |
461 | ||
462 | netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno, | |
463 | c_can_read_reg32(priv, &priv->regs->msgval1)); | |
464 | } | |
465 | ||
466 | static void c_can_inval_msg_object(struct net_device *dev, int iface, int objno) | |
467 | { | |
468 | struct c_can_priv *priv = netdev_priv(dev); | |
469 | ||
470 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb1, 0); | |
471 | priv->write_reg(priv, &priv->regs->ifregs[iface].arb2, 0); | |
472 | priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, 0); | |
473 | ||
474 | c_can_object_put(dev, iface, objno, IF_COMM_ARB | IF_COMM_CONTROL); | |
475 | ||
476 | netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno, | |
477 | c_can_read_reg32(priv, &priv->regs->msgval1)); | |
478 | } | |
479 | ||
480 | static inline int c_can_is_next_tx_obj_busy(struct c_can_priv *priv, int objno) | |
481 | { | |
482 | int val = c_can_read_reg32(priv, &priv->regs->txrqst1); | |
483 | ||
484 | /* | |
485 | * as transmission request register's bit n-1 corresponds to | |
486 | * message object n, we need to handle the same properly. | |
487 | */ | |
488 | if (val & (1 << (objno - 1))) | |
489 | return 1; | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
494 | static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, | |
495 | struct net_device *dev) | |
496 | { | |
497 | u32 msg_obj_no; | |
498 | struct c_can_priv *priv = netdev_priv(dev); | |
499 | struct can_frame *frame = (struct can_frame *)skb->data; | |
500 | ||
501 | if (can_dropped_invalid_skb(dev, skb)) | |
502 | return NETDEV_TX_OK; | |
503 | ||
504 | msg_obj_no = get_tx_next_msg_obj(priv); | |
505 | ||
506 | /* prepare message object for transmission */ | |
507 | c_can_write_msg_object(dev, 0, frame, msg_obj_no); | |
508 | can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); | |
509 | ||
510 | /* | |
511 | * we have to stop the queue in case of a wrap around or | |
512 | * if the next TX message object is still in use | |
513 | */ | |
514 | priv->tx_next++; | |
515 | if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) || | |
516 | (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0) | |
517 | netif_stop_queue(dev); | |
518 | ||
519 | return NETDEV_TX_OK; | |
520 | } | |
521 | ||
522 | static int c_can_set_bittiming(struct net_device *dev) | |
523 | { | |
524 | unsigned int reg_btr, reg_brpe, ctrl_save; | |
525 | u8 brp, brpe, sjw, tseg1, tseg2; | |
526 | u32 ten_bit_brp; | |
527 | struct c_can_priv *priv = netdev_priv(dev); | |
528 | const struct can_bittiming *bt = &priv->can.bittiming; | |
529 | ||
530 | /* c_can provides a 6-bit brp and 4-bit brpe fields */ | |
531 | ten_bit_brp = bt->brp - 1; | |
532 | brp = ten_bit_brp & BTR_BRP_MASK; | |
533 | brpe = ten_bit_brp >> 6; | |
534 | ||
535 | sjw = bt->sjw - 1; | |
536 | tseg1 = bt->prop_seg + bt->phase_seg1 - 1; | |
537 | tseg2 = bt->phase_seg2 - 1; | |
538 | reg_btr = brp | (sjw << BTR_SJW_SHIFT) | (tseg1 << BTR_TSEG1_SHIFT) | | |
539 | (tseg2 << BTR_TSEG2_SHIFT); | |
540 | reg_brpe = brpe & BRP_EXT_BRPE_MASK; | |
541 | ||
542 | netdev_info(dev, | |
543 | "setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe); | |
544 | ||
545 | ctrl_save = priv->read_reg(priv, &priv->regs->control); | |
546 | priv->write_reg(priv, &priv->regs->control, | |
547 | ctrl_save | CONTROL_CCE | CONTROL_INIT); | |
548 | priv->write_reg(priv, &priv->regs->btr, reg_btr); | |
549 | priv->write_reg(priv, &priv->regs->brp_ext, reg_brpe); | |
550 | priv->write_reg(priv, &priv->regs->control, ctrl_save); | |
551 | ||
552 | return 0; | |
553 | } | |
554 | ||
555 | /* | |
556 | * Configure C_CAN message objects for Tx and Rx purposes: | |
557 | * C_CAN provides a total of 32 message objects that can be configured | |
558 | * either for Tx or Rx purposes. Here the first 16 message objects are used as | |
559 | * a reception FIFO. The end of reception FIFO is signified by the EoB bit | |
560 | * being SET. The remaining 16 message objects are kept aside for Tx purposes. | |
561 | * See user guide document for further details on configuring message | |
562 | * objects. | |
563 | */ | |
564 | static void c_can_configure_msg_objects(struct net_device *dev) | |
565 | { | |
566 | int i; | |
567 | ||
568 | /* first invalidate all message objects */ | |
569 | for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_NO_OF_OBJECTS; i++) | |
570 | c_can_inval_msg_object(dev, 0, i); | |
571 | ||
572 | /* setup receive message objects */ | |
573 | for (i = C_CAN_MSG_OBJ_RX_FIRST; i < C_CAN_MSG_OBJ_RX_LAST; i++) | |
574 | c_can_setup_receive_object(dev, 0, i, 0, 0, | |
575 | (IF_MCONT_RXIE | IF_MCONT_UMASK) & ~IF_MCONT_EOB); | |
576 | ||
577 | c_can_setup_receive_object(dev, 0, C_CAN_MSG_OBJ_RX_LAST, 0, 0, | |
578 | IF_MCONT_EOB | IF_MCONT_RXIE | IF_MCONT_UMASK); | |
579 | } | |
580 | ||
581 | /* | |
582 | * Configure C_CAN chip: | |
583 | * - enable/disable auto-retransmission | |
584 | * - set operating mode | |
585 | * - configure message objects | |
586 | */ | |
587 | static void c_can_chip_config(struct net_device *dev) | |
588 | { | |
589 | struct c_can_priv *priv = netdev_priv(dev); | |
590 | ||
591 | if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) | |
592 | /* disable automatic retransmission */ | |
593 | priv->write_reg(priv, &priv->regs->control, | |
594 | CONTROL_DISABLE_AR); | |
595 | else | |
596 | /* enable automatic retransmission */ | |
597 | priv->write_reg(priv, &priv->regs->control, | |
598 | CONTROL_ENABLE_AR); | |
599 | ||
600 | if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY & | |
601 | CAN_CTRLMODE_LOOPBACK)) { | |
602 | /* loopback + silent mode : useful for hot self-test */ | |
603 | priv->write_reg(priv, &priv->regs->control, CONTROL_EIE | | |
604 | CONTROL_SIE | CONTROL_IE | CONTROL_TEST); | |
605 | priv->write_reg(priv, &priv->regs->test, | |
606 | TEST_LBACK | TEST_SILENT); | |
607 | } else if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { | |
608 | /* loopback mode : useful for self-test function */ | |
609 | priv->write_reg(priv, &priv->regs->control, CONTROL_EIE | | |
610 | CONTROL_SIE | CONTROL_IE | CONTROL_TEST); | |
611 | priv->write_reg(priv, &priv->regs->test, TEST_LBACK); | |
612 | } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) { | |
613 | /* silent mode : bus-monitoring mode */ | |
614 | priv->write_reg(priv, &priv->regs->control, CONTROL_EIE | | |
615 | CONTROL_SIE | CONTROL_IE | CONTROL_TEST); | |
616 | priv->write_reg(priv, &priv->regs->test, TEST_SILENT); | |
617 | } else | |
618 | /* normal mode*/ | |
619 | priv->write_reg(priv, &priv->regs->control, | |
620 | CONTROL_EIE | CONTROL_SIE | CONTROL_IE); | |
621 | ||
622 | /* configure message objects */ | |
623 | c_can_configure_msg_objects(dev); | |
624 | ||
625 | /* set a `lec` value so that we can check for updates later */ | |
626 | priv->write_reg(priv, &priv->regs->status, LEC_UNUSED); | |
627 | ||
628 | /* set bittiming params */ | |
629 | c_can_set_bittiming(dev); | |
630 | } | |
631 | ||
632 | static void c_can_start(struct net_device *dev) | |
633 | { | |
634 | struct c_can_priv *priv = netdev_priv(dev); | |
635 | ||
881ff67a BS |
636 | /* basic c_can configuration */ |
637 | c_can_chip_config(dev); | |
638 | ||
639 | priv->can.state = CAN_STATE_ERROR_ACTIVE; | |
640 | ||
641 | /* reset tx helper pointers */ | |
642 | priv->tx_next = priv->tx_echo = 0; | |
4f2d56c4 JA |
643 | |
644 | /* enable status change, error and module interrupts */ | |
645 | c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS); | |
881ff67a BS |
646 | } |
647 | ||
648 | static void c_can_stop(struct net_device *dev) | |
649 | { | |
650 | struct c_can_priv *priv = netdev_priv(dev); | |
651 | ||
652 | /* disable all interrupts */ | |
653 | c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS); | |
654 | ||
655 | /* set the state as STOPPED */ | |
656 | priv->can.state = CAN_STATE_STOPPED; | |
657 | } | |
658 | ||
659 | static int c_can_set_mode(struct net_device *dev, enum can_mode mode) | |
660 | { | |
661 | switch (mode) { | |
662 | case CAN_MODE_START: | |
663 | c_can_start(dev); | |
664 | netif_wake_queue(dev); | |
665 | break; | |
666 | default: | |
667 | return -EOPNOTSUPP; | |
668 | } | |
669 | ||
670 | return 0; | |
671 | } | |
672 | ||
673 | static int c_can_get_berr_counter(const struct net_device *dev, | |
674 | struct can_berr_counter *bec) | |
675 | { | |
676 | unsigned int reg_err_counter; | |
677 | struct c_can_priv *priv = netdev_priv(dev); | |
678 | ||
679 | reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt); | |
680 | bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >> | |
681 | ERR_CNT_REC_SHIFT; | |
682 | bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK; | |
683 | ||
684 | return 0; | |
685 | } | |
686 | ||
687 | /* | |
688 | * theory of operation: | |
689 | * | |
690 | * priv->tx_echo holds the number of the oldest can_frame put for | |
691 | * transmission into the hardware, but not yet ACKed by the CAN tx | |
692 | * complete IRQ. | |
693 | * | |
694 | * We iterate from priv->tx_echo to priv->tx_next and check if the | |
695 | * packet has been transmitted, echo it back to the CAN framework. | |
696 | * If we discover a not yet transmitted package, stop looking for more. | |
697 | */ | |
698 | static void c_can_do_tx(struct net_device *dev) | |
699 | { | |
700 | u32 val; | |
701 | u32 msg_obj_no; | |
702 | struct c_can_priv *priv = netdev_priv(dev); | |
703 | struct net_device_stats *stats = &dev->stats; | |
704 | ||
705 | for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { | |
706 | msg_obj_no = get_tx_echo_msg_obj(priv); | |
707 | c_can_inval_msg_object(dev, 0, msg_obj_no); | |
708 | val = c_can_read_reg32(priv, &priv->regs->txrqst1); | |
709 | if (!(val & (1 << msg_obj_no))) { | |
710 | can_get_echo_skb(dev, | |
711 | msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); | |
712 | stats->tx_bytes += priv->read_reg(priv, | |
713 | &priv->regs->ifregs[0].msg_cntrl) | |
714 | & IF_MCONT_DLC_MASK; | |
715 | stats->tx_packets++; | |
716 | } | |
717 | } | |
718 | ||
719 | /* restart queue if wrap-up or if queue stalled on last pkt */ | |
720 | if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) || | |
721 | ((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0)) | |
722 | netif_wake_queue(dev); | |
723 | } | |
724 | ||
725 | /* | |
726 | * theory of operation: | |
727 | * | |
728 | * c_can core saves a received CAN message into the first free message | |
729 | * object it finds free (starting with the lowest). Bits NEWDAT and | |
730 | * INTPND are set for this message object indicating that a new message | |
731 | * has arrived. To work-around this issue, we keep two groups of message | |
732 | * objects whose partitioning is defined by C_CAN_MSG_OBJ_RX_SPLIT. | |
733 | * | |
734 | * To ensure in-order frame reception we use the following | |
735 | * approach while re-activating a message object to receive further | |
736 | * frames: | |
737 | * - if the current message object number is lower than | |
738 | * C_CAN_MSG_RX_LOW_LAST, do not clear the NEWDAT bit while clearing | |
739 | * the INTPND bit. | |
740 | * - if the current message object number is equal to | |
741 | * C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of all lower | |
742 | * receive message objects. | |
743 | * - if the current message object number is greater than | |
744 | * C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of | |
745 | * only this message object. | |
746 | */ | |
747 | static int c_can_do_rx_poll(struct net_device *dev, int quota) | |
748 | { | |
749 | u32 num_rx_pkts = 0; | |
750 | unsigned int msg_obj, msg_ctrl_save; | |
751 | struct c_can_priv *priv = netdev_priv(dev); | |
752 | u32 val = c_can_read_reg32(priv, &priv->regs->intpnd1); | |
753 | ||
754 | for (msg_obj = C_CAN_MSG_OBJ_RX_FIRST; | |
755 | msg_obj <= C_CAN_MSG_OBJ_RX_LAST && quota > 0; | |
756 | val = c_can_read_reg32(priv, &priv->regs->intpnd1), | |
757 | msg_obj++) { | |
758 | /* | |
759 | * as interrupt pending register's bit n-1 corresponds to | |
760 | * message object n, we need to handle the same properly. | |
761 | */ | |
762 | if (val & (1 << (msg_obj - 1))) { | |
763 | c_can_object_get(dev, 0, msg_obj, IF_COMM_ALL & | |
764 | ~IF_COMM_TXRQST); | |
765 | msg_ctrl_save = priv->read_reg(priv, | |
766 | &priv->regs->ifregs[0].msg_cntrl); | |
767 | ||
768 | if (msg_ctrl_save & IF_MCONT_EOB) | |
769 | return num_rx_pkts; | |
770 | ||
771 | if (msg_ctrl_save & IF_MCONT_MSGLST) { | |
772 | c_can_handle_lost_msg_obj(dev, 0, msg_obj); | |
773 | num_rx_pkts++; | |
774 | quota--; | |
775 | continue; | |
776 | } | |
777 | ||
778 | if (!(msg_ctrl_save & IF_MCONT_NEWDAT)) | |
779 | continue; | |
780 | ||
781 | /* read the data from the message object */ | |
782 | c_can_read_msg_object(dev, 0, msg_ctrl_save); | |
783 | ||
784 | if (msg_obj < C_CAN_MSG_RX_LOW_LAST) | |
785 | c_can_mark_rx_msg_obj(dev, 0, | |
786 | msg_ctrl_save, msg_obj); | |
787 | else if (msg_obj > C_CAN_MSG_RX_LOW_LAST) | |
788 | /* activate this msg obj */ | |
789 | c_can_activate_rx_msg_obj(dev, 0, | |
790 | msg_ctrl_save, msg_obj); | |
791 | else if (msg_obj == C_CAN_MSG_RX_LOW_LAST) | |
792 | /* activate all lower message objects */ | |
793 | c_can_activate_all_lower_rx_msg_obj(dev, | |
794 | 0, msg_ctrl_save); | |
795 | ||
796 | num_rx_pkts++; | |
797 | quota--; | |
798 | } | |
799 | } | |
800 | ||
801 | return num_rx_pkts; | |
802 | } | |
803 | ||
804 | static inline int c_can_has_and_handle_berr(struct c_can_priv *priv) | |
805 | { | |
806 | return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) && | |
807 | (priv->current_status & LEC_UNUSED); | |
808 | } | |
809 | ||
810 | static int c_can_handle_state_change(struct net_device *dev, | |
811 | enum c_can_bus_error_types error_type) | |
812 | { | |
813 | unsigned int reg_err_counter; | |
814 | unsigned int rx_err_passive; | |
815 | struct c_can_priv *priv = netdev_priv(dev); | |
816 | struct net_device_stats *stats = &dev->stats; | |
817 | struct can_frame *cf; | |
818 | struct sk_buff *skb; | |
819 | struct can_berr_counter bec; | |
820 | ||
821 | /* propogate the error condition to the CAN stack */ | |
822 | skb = alloc_can_err_skb(dev, &cf); | |
823 | if (unlikely(!skb)) | |
824 | return 0; | |
825 | ||
826 | c_can_get_berr_counter(dev, &bec); | |
827 | reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt); | |
828 | rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >> | |
829 | ERR_CNT_RP_SHIFT; | |
830 | ||
831 | switch (error_type) { | |
832 | case C_CAN_ERROR_WARNING: | |
833 | /* error warning state */ | |
834 | priv->can.can_stats.error_warning++; | |
835 | priv->can.state = CAN_STATE_ERROR_WARNING; | |
836 | cf->can_id |= CAN_ERR_CRTL; | |
837 | cf->data[1] = (bec.txerr > bec.rxerr) ? | |
838 | CAN_ERR_CRTL_TX_WARNING : | |
839 | CAN_ERR_CRTL_RX_WARNING; | |
840 | cf->data[6] = bec.txerr; | |
841 | cf->data[7] = bec.rxerr; | |
842 | ||
843 | break; | |
844 | case C_CAN_ERROR_PASSIVE: | |
845 | /* error passive state */ | |
846 | priv->can.can_stats.error_passive++; | |
847 | priv->can.state = CAN_STATE_ERROR_PASSIVE; | |
848 | cf->can_id |= CAN_ERR_CRTL; | |
849 | if (rx_err_passive) | |
850 | cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; | |
851 | if (bec.txerr > 127) | |
852 | cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; | |
853 | ||
854 | cf->data[6] = bec.txerr; | |
855 | cf->data[7] = bec.rxerr; | |
856 | break; | |
857 | case C_CAN_BUS_OFF: | |
858 | /* bus-off state */ | |
859 | priv->can.state = CAN_STATE_BUS_OFF; | |
860 | cf->can_id |= CAN_ERR_BUSOFF; | |
861 | /* | |
862 | * disable all interrupts in bus-off mode to ensure that | |
863 | * the CPU is not hogged down | |
864 | */ | |
865 | c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS); | |
866 | can_bus_off(dev); | |
867 | break; | |
868 | default: | |
869 | break; | |
870 | } | |
871 | ||
872 | netif_receive_skb(skb); | |
873 | stats->rx_packets++; | |
874 | stats->rx_bytes += cf->can_dlc; | |
875 | ||
876 | return 1; | |
877 | } | |
878 | ||
879 | static int c_can_handle_bus_err(struct net_device *dev, | |
880 | enum c_can_lec_type lec_type) | |
881 | { | |
882 | struct c_can_priv *priv = netdev_priv(dev); | |
883 | struct net_device_stats *stats = &dev->stats; | |
884 | struct can_frame *cf; | |
885 | struct sk_buff *skb; | |
886 | ||
887 | /* | |
888 | * early exit if no lec update or no error. | |
889 | * no lec update means that no CAN bus event has been detected | |
890 | * since CPU wrote 0x7 value to status reg. | |
891 | */ | |
892 | if (lec_type == LEC_UNUSED || lec_type == LEC_NO_ERROR) | |
893 | return 0; | |
894 | ||
895 | /* propogate the error condition to the CAN stack */ | |
896 | skb = alloc_can_err_skb(dev, &cf); | |
897 | if (unlikely(!skb)) | |
898 | return 0; | |
899 | ||
900 | /* | |
901 | * check for 'last error code' which tells us the | |
902 | * type of the last error to occur on the CAN bus | |
903 | */ | |
904 | ||
905 | /* common for all type of bus errors */ | |
906 | priv->can.can_stats.bus_error++; | |
907 | stats->rx_errors++; | |
908 | cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; | |
909 | cf->data[2] |= CAN_ERR_PROT_UNSPEC; | |
910 | ||
911 | switch (lec_type) { | |
912 | case LEC_STUFF_ERROR: | |
913 | netdev_dbg(dev, "stuff error\n"); | |
914 | cf->data[2] |= CAN_ERR_PROT_STUFF; | |
915 | break; | |
916 | case LEC_FORM_ERROR: | |
917 | netdev_dbg(dev, "form error\n"); | |
918 | cf->data[2] |= CAN_ERR_PROT_FORM; | |
919 | break; | |
920 | case LEC_ACK_ERROR: | |
921 | netdev_dbg(dev, "ack error\n"); | |
922 | cf->data[2] |= (CAN_ERR_PROT_LOC_ACK | | |
923 | CAN_ERR_PROT_LOC_ACK_DEL); | |
924 | break; | |
925 | case LEC_BIT1_ERROR: | |
926 | netdev_dbg(dev, "bit1 error\n"); | |
927 | cf->data[2] |= CAN_ERR_PROT_BIT1; | |
928 | break; | |
929 | case LEC_BIT0_ERROR: | |
930 | netdev_dbg(dev, "bit0 error\n"); | |
931 | cf->data[2] |= CAN_ERR_PROT_BIT0; | |
932 | break; | |
933 | case LEC_CRC_ERROR: | |
934 | netdev_dbg(dev, "CRC error\n"); | |
935 | cf->data[2] |= (CAN_ERR_PROT_LOC_CRC_SEQ | | |
936 | CAN_ERR_PROT_LOC_CRC_DEL); | |
937 | break; | |
938 | default: | |
939 | break; | |
940 | } | |
941 | ||
942 | /* set a `lec` value so that we can check for updates later */ | |
943 | priv->write_reg(priv, &priv->regs->status, LEC_UNUSED); | |
944 | ||
945 | netif_receive_skb(skb); | |
946 | stats->rx_packets++; | |
947 | stats->rx_bytes += cf->can_dlc; | |
948 | ||
949 | return 1; | |
950 | } | |
951 | ||
952 | static int c_can_poll(struct napi_struct *napi, int quota) | |
953 | { | |
954 | u16 irqstatus; | |
955 | int lec_type = 0; | |
956 | int work_done = 0; | |
957 | struct net_device *dev = napi->dev; | |
958 | struct c_can_priv *priv = netdev_priv(dev); | |
959 | ||
960 | irqstatus = priv->read_reg(priv, &priv->regs->interrupt); | |
961 | if (!irqstatus) | |
962 | goto end; | |
963 | ||
964 | /* status events have the highest priority */ | |
965 | if (irqstatus == STATUS_INTERRUPT) { | |
966 | priv->current_status = priv->read_reg(priv, | |
967 | &priv->regs->status); | |
968 | ||
969 | /* handle Tx/Rx events */ | |
970 | if (priv->current_status & STATUS_TXOK) | |
971 | priv->write_reg(priv, &priv->regs->status, | |
972 | priv->current_status & ~STATUS_TXOK); | |
973 | ||
974 | if (priv->current_status & STATUS_RXOK) | |
975 | priv->write_reg(priv, &priv->regs->status, | |
976 | priv->current_status & ~STATUS_RXOK); | |
977 | ||
978 | /* handle state changes */ | |
979 | if ((priv->current_status & STATUS_EWARN) && | |
980 | (!(priv->last_status & STATUS_EWARN))) { | |
981 | netdev_dbg(dev, "entered error warning state\n"); | |
982 | work_done += c_can_handle_state_change(dev, | |
983 | C_CAN_ERROR_WARNING); | |
984 | } | |
985 | if ((priv->current_status & STATUS_EPASS) && | |
986 | (!(priv->last_status & STATUS_EPASS))) { | |
987 | netdev_dbg(dev, "entered error passive state\n"); | |
988 | work_done += c_can_handle_state_change(dev, | |
989 | C_CAN_ERROR_PASSIVE); | |
990 | } | |
991 | if ((priv->current_status & STATUS_BOFF) && | |
992 | (!(priv->last_status & STATUS_BOFF))) { | |
993 | netdev_dbg(dev, "entered bus off state\n"); | |
994 | work_done += c_can_handle_state_change(dev, | |
995 | C_CAN_BUS_OFF); | |
996 | } | |
997 | ||
998 | /* handle bus recovery events */ | |
999 | if ((!(priv->current_status & STATUS_BOFF)) && | |
1000 | (priv->last_status & STATUS_BOFF)) { | |
1001 | netdev_dbg(dev, "left bus off state\n"); | |
1002 | priv->can.state = CAN_STATE_ERROR_ACTIVE; | |
1003 | } | |
1004 | if ((!(priv->current_status & STATUS_EPASS)) && | |
1005 | (priv->last_status & STATUS_EPASS)) { | |
1006 | netdev_dbg(dev, "left error passive state\n"); | |
1007 | priv->can.state = CAN_STATE_ERROR_ACTIVE; | |
1008 | } | |
1009 | ||
1010 | priv->last_status = priv->current_status; | |
1011 | ||
1012 | /* handle lec errors on the bus */ | |
1013 | lec_type = c_can_has_and_handle_berr(priv); | |
1014 | if (lec_type) | |
1015 | work_done += c_can_handle_bus_err(dev, lec_type); | |
1016 | } else if ((irqstatus >= C_CAN_MSG_OBJ_RX_FIRST) && | |
1017 | (irqstatus <= C_CAN_MSG_OBJ_RX_LAST)) { | |
1018 | /* handle events corresponding to receive message objects */ | |
1019 | work_done += c_can_do_rx_poll(dev, (quota - work_done)); | |
1020 | } else if ((irqstatus >= C_CAN_MSG_OBJ_TX_FIRST) && | |
1021 | (irqstatus <= C_CAN_MSG_OBJ_TX_LAST)) { | |
1022 | /* handle events corresponding to transmit message objects */ | |
1023 | c_can_do_tx(dev); | |
1024 | } | |
1025 | ||
1026 | end: | |
1027 | if (work_done < quota) { | |
1028 | napi_complete(napi); | |
1029 | /* enable all IRQs */ | |
1030 | c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS); | |
1031 | } | |
1032 | ||
1033 | return work_done; | |
1034 | } | |
1035 | ||
1036 | static irqreturn_t c_can_isr(int irq, void *dev_id) | |
1037 | { | |
1038 | u16 irqstatus; | |
1039 | struct net_device *dev = (struct net_device *)dev_id; | |
1040 | struct c_can_priv *priv = netdev_priv(dev); | |
1041 | ||
1042 | irqstatus = priv->read_reg(priv, &priv->regs->interrupt); | |
1043 | if (!irqstatus) | |
1044 | return IRQ_NONE; | |
1045 | ||
1046 | /* disable all interrupts and schedule the NAPI */ | |
1047 | c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS); | |
1048 | napi_schedule(&priv->napi); | |
1049 | ||
1050 | return IRQ_HANDLED; | |
1051 | } | |
1052 | ||
1053 | static int c_can_open(struct net_device *dev) | |
1054 | { | |
1055 | int err; | |
1056 | struct c_can_priv *priv = netdev_priv(dev); | |
1057 | ||
1058 | /* open the can device */ | |
1059 | err = open_candev(dev); | |
1060 | if (err) { | |
1061 | netdev_err(dev, "failed to open can device\n"); | |
1062 | return err; | |
1063 | } | |
1064 | ||
1065 | /* register interrupt handler */ | |
1066 | err = request_irq(dev->irq, &c_can_isr, IRQF_SHARED, dev->name, | |
1067 | dev); | |
1068 | if (err < 0) { | |
1069 | netdev_err(dev, "failed to request interrupt\n"); | |
1070 | goto exit_irq_fail; | |
1071 | } | |
1072 | ||
1073 | /* start the c_can controller */ | |
1074 | c_can_start(dev); | |
1075 | ||
1076 | napi_enable(&priv->napi); | |
1077 | netif_start_queue(dev); | |
1078 | ||
1079 | return 0; | |
1080 | ||
1081 | exit_irq_fail: | |
1082 | close_candev(dev); | |
1083 | return err; | |
1084 | } | |
1085 | ||
1086 | static int c_can_close(struct net_device *dev) | |
1087 | { | |
1088 | struct c_can_priv *priv = netdev_priv(dev); | |
1089 | ||
1090 | netif_stop_queue(dev); | |
1091 | napi_disable(&priv->napi); | |
1092 | c_can_stop(dev); | |
1093 | free_irq(dev->irq, dev); | |
1094 | close_candev(dev); | |
1095 | ||
1096 | return 0; | |
1097 | } | |
1098 | ||
1099 | struct net_device *alloc_c_can_dev(void) | |
1100 | { | |
1101 | struct net_device *dev; | |
1102 | struct c_can_priv *priv; | |
1103 | ||
1104 | dev = alloc_candev(sizeof(struct c_can_priv), C_CAN_MSG_OBJ_TX_NUM); | |
1105 | if (!dev) | |
1106 | return NULL; | |
1107 | ||
1108 | priv = netdev_priv(dev); | |
1109 | netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT); | |
1110 | ||
1111 | priv->dev = dev; | |
1112 | priv->can.bittiming_const = &c_can_bittiming_const; | |
1113 | priv->can.do_set_mode = c_can_set_mode; | |
1114 | priv->can.do_get_berr_counter = c_can_get_berr_counter; | |
1115 | priv->can.ctrlmode_supported = CAN_CTRLMODE_ONE_SHOT | | |
1116 | CAN_CTRLMODE_LOOPBACK | | |
1117 | CAN_CTRLMODE_LISTENONLY | | |
1118 | CAN_CTRLMODE_BERR_REPORTING; | |
1119 | ||
1120 | return dev; | |
1121 | } | |
1122 | EXPORT_SYMBOL_GPL(alloc_c_can_dev); | |
1123 | ||
1124 | void free_c_can_dev(struct net_device *dev) | |
1125 | { | |
1126 | free_candev(dev); | |
1127 | } | |
1128 | EXPORT_SYMBOL_GPL(free_c_can_dev); | |
1129 | ||
1130 | static const struct net_device_ops c_can_netdev_ops = { | |
1131 | .ndo_open = c_can_open, | |
1132 | .ndo_stop = c_can_close, | |
1133 | .ndo_start_xmit = c_can_start_xmit, | |
1134 | }; | |
1135 | ||
1136 | int register_c_can_dev(struct net_device *dev) | |
1137 | { | |
1138 | dev->flags |= IFF_ECHO; /* we support local echo */ | |
1139 | dev->netdev_ops = &c_can_netdev_ops; | |
1140 | ||
1141 | return register_candev(dev); | |
1142 | } | |
1143 | EXPORT_SYMBOL_GPL(register_c_can_dev); | |
1144 | ||
1145 | void unregister_c_can_dev(struct net_device *dev) | |
1146 | { | |
1147 | struct c_can_priv *priv = netdev_priv(dev); | |
1148 | ||
1149 | /* disable all interrupts */ | |
1150 | c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS); | |
1151 | ||
1152 | unregister_candev(dev); | |
1153 | } | |
1154 | EXPORT_SYMBOL_GPL(unregister_c_can_dev); | |
1155 | ||
1156 | MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); | |
1157 | MODULE_LICENSE("GPL v2"); | |
1158 | MODULE_DESCRIPTION("CAN bus driver for Bosch C_CAN controller"); |