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pvrusb2: reduce stack usage pvr2_eeprom_analyze()
[linux/fpc-iii.git] / drivers / net / can / ti_hecc.c
blob6749b1829469411315dedac1634b7be974cf21d8
1 /*
2 * TI HECC (CAN) device driver
3 *
4 * This driver supports TI's HECC (High End CAN Controller module) and the
5 * specs for the same is available at <http://www.ti.com>
6 *
7 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation version 2.
12 *
13 * This program is distributed as is WITHOUT ANY WARRANTY of any
14 * kind, whether express or implied; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 */
19
20 /*
21 * Your platform definitions should specify module ram offsets and interrupt
22 * number to use as follows:
23 *
24 * static struct ti_hecc_platform_data am3517_evm_hecc_pdata = {
25 * .scc_hecc_offset = 0,
26 * .scc_ram_offset = 0x3000,
27 * .hecc_ram_offset = 0x3000,
28 * .mbx_offset = 0x2000,
29 * .int_line = 0,
30 * .revision = 1,
31 * .transceiver_switch = hecc_phy_control,
32 * };
33 *
34 * Please see include/linux/can/platform/ti_hecc.h for description of
35 * above fields.
36 *
37 */
38
39 #include <linux/module.h>
40 #include <linux/kernel.h>
41 #include <linux/types.h>
42 #include <linux/interrupt.h>
43 #include <linux/errno.h>
44 #include <linux/netdevice.h>
45 #include <linux/skbuff.h>
46 #include <linux/platform_device.h>
47 #include <linux/clk.h>
48 #include <linux/io.h>
49
50 #include <linux/can/dev.h>
51 #include <linux/can/error.h>
52 #include <linux/can/led.h>
53 #include <linux/can/platform/ti_hecc.h>
54
55 #define DRV_NAME "ti_hecc"
56 #define HECC_MODULE_VERSION "0.7"
57 MODULE_VERSION(HECC_MODULE_VERSION);
58 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
59
60 /* TX / RX Mailbox Configuration */
61 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
62 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */
63
64 /*
65 * Important Note: TX mailbox configuration
66 * TX mailboxes should be restricted to the number of SKB buffers to avoid
67 * maintaining SKB buffers separately. TX mailboxes should be a power of 2
68 * for the mailbox logic to work. Top mailbox numbers are reserved for RX
69 * and lower mailboxes for TX.
70 *
71 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
72 * 4 (default) 2
73 * 8 3
74 * 16 4
75 */
76 #define HECC_MB_TX_SHIFT 2 /* as per table above */
77 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
78
79 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
80 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
81 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
82 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
83 #define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1))
84 #define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX
85
86 /*
87 * Important Note: RX mailbox configuration
88 * RX mailboxes are further logically split into two - main and buffer
89 * mailboxes. The goal is to get all packets into main mailboxes as
90 * driven by mailbox number and receive priority (higher to lower) and
91 * buffer mailboxes are used to receive pkts while main mailboxes are being
92 * processed. This ensures in-order packet reception.
93 *
94 * Here are the recommended values for buffer mailbox. Note that RX mailboxes
95 * start after TX mailboxes:
96 *
97 * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes
98 * 28 12 8
99 * 16 20 4
100 */
101
102 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
103 #define HECC_RX_BUFFER_MBOX 12 /* as per table above */
104 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
105 #define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1))
106
107 /* TI HECC module registers */
108 #define HECC_CANME 0x0 /* Mailbox enable */
109 #define HECC_CANMD 0x4 /* Mailbox direction */
110 #define HECC_CANTRS 0x8 /* Transmit request set */
111 #define HECC_CANTRR 0xC /* Transmit request */
112 #define HECC_CANTA 0x10 /* Transmission acknowledge */
113 #define HECC_CANAA 0x14 /* Abort acknowledge */
114 #define HECC_CANRMP 0x18 /* Receive message pending */
115 #define HECC_CANRML 0x1C /* Remote message lost */
116 #define HECC_CANRFP 0x20 /* Remote frame pending */
117 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
118 #define HECC_CANMC 0x28 /* Master control */
119 #define HECC_CANBTC 0x2C /* Bit timing configuration */
120 #define HECC_CANES 0x30 /* Error and status */
121 #define HECC_CANTEC 0x34 /* Transmit error counter */
122 #define HECC_CANREC 0x38 /* Receive error counter */
123 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
124 #define HECC_CANGIM 0x40 /* Global interrupt mask */
125 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
126 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
127 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */
128 #define HECC_CANOPC 0x50 /* Overwrite protection control */
129 #define HECC_CANTIOC 0x54 /* Transmit I/O control */
130 #define HECC_CANRIOC 0x58 /* Receive I/O control */
131 #define HECC_CANLNT 0x5C /* HECC only: Local network time */
132 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */
133 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */
134 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
135 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
136
137 /* Mailbox registers */
138 #define HECC_CANMID 0x0
139 #define HECC_CANMCF 0x4
140 #define HECC_CANMDL 0x8
141 #define HECC_CANMDH 0xC
142
143 #define HECC_SET_REG 0xFFFFFFFF
144 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
145 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
146
147 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
148 #define HECC_CANMC_CCR BIT(12) /* Change config request */
149 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
150 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
151 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
152 #define HECC_CANMC_SRES BIT(5) /* Software reset */
153
154 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
155 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
156
157 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */
158 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
159 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
160
161 #define HECC_CANES_FE BIT(24) /* form error */
162 #define HECC_CANES_BE BIT(23) /* bit error */
163 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
164 #define HECC_CANES_CRCE BIT(21) /* CRC error */
165 #define HECC_CANES_SE BIT(20) /* stuff bit error */
166 #define HECC_CANES_ACKE BIT(19) /* ack error */
167 #define HECC_CANES_BO BIT(18) /* Bus off status */
168 #define HECC_CANES_EP BIT(17) /* Error passive status */
169 #define HECC_CANES_EW BIT(16) /* Error warning status */
170 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */
171 #define HECC_CANES_CCE BIT(4) /* Change config enabled */
172 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */
173
174 #define HECC_CANBTC_SAM BIT(7) /* sample points */
175
176 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
177 HECC_CANES_CRCE | HECC_CANES_SE |\
178 HECC_CANES_ACKE)
179
180 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
181
182 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
183 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
184 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
185 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
186 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
187 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
188 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
189 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
190 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
191 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
192 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
193 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
194 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
195 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
196 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
197
198 /* CAN Bittiming constants as per HECC specs */
199 static const struct can_bittiming_const ti_hecc_bittiming_const = {
200 .name = DRV_NAME,
201 .tseg1_min = 1,
202 .tseg1_max = 16,
203 .tseg2_min = 1,
204 .tseg2_max = 8,
205 .sjw_max = 4,
206 .brp_min = 1,
207 .brp_max = 256,
208 .brp_inc = 1,
209 };
210
211 struct ti_hecc_priv {
212 struct can_priv can; /* MUST be first member/field */
213 struct napi_struct napi;
214 struct net_device *ndev;
215 struct clk *clk;
216 void __iomem *base;
217 u32 scc_ram_offset;
218 u32 hecc_ram_offset;
219 u32 mbx_offset;
220 u32 int_line;
221 spinlock_t mbx_lock; /* CANME register needs protection */
222 u32 tx_head;
223 u32 tx_tail;
224 u32 rx_next;
225 void (*transceiver_switch)(int);
226 };
227
228 static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
229 {
230 return priv->tx_head & HECC_TX_MB_MASK;
231 }
232
233 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
234 {
235 return priv->tx_tail & HECC_TX_MB_MASK;
236 }
237
238 static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
239 {
240 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
241 }
242
243 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
244 {
245 __raw_writel(val, priv->base + priv->hecc_ram_offset + mbxno * 4);
246 }
247
248 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
249 u32 reg, u32 val)
250 {
251 __raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 +
252 reg);
253 }
254
255 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
256 {
257 return __raw_readl(priv->base + priv->mbx_offset + mbxno * 0x10 +
258 reg);
259 }
260
261 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
262 {
263 __raw_writel(val, priv->base + reg);
264 }
265
266 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
267 {
268 return __raw_readl(priv->base + reg);
269 }
270
271 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
272 u32 bit_mask)
273 {
274 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
275 }
276
277 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
278 u32 bit_mask)
279 {
280 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
281 }
282
283 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
284 {
285 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
286 }
287
288 static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
289 {
290 struct can_bittiming *bit_timing = &priv->can.bittiming;
291 u32 can_btc;
292
293 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
294 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
295 & 0xF) << 3;
296 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
297 if (bit_timing->brp > 4)
298 can_btc |= HECC_CANBTC_SAM;
299 else
300 netdev_warn(priv->ndev, "WARN: Triple"
301 "sampling not set due to h/w limitations");
302 }
303 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
304 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
305
306 /* ERM being set to 0 by default meaning resync at falling edge */
307
308 hecc_write(priv, HECC_CANBTC, can_btc);
309 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
310
311 return 0;
312 }
313
314 static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
315 int on)
316 {
317 if (priv->transceiver_switch)
318 priv->transceiver_switch(on);
319 }
320
321 static void ti_hecc_reset(struct net_device *ndev)
322 {
323 u32 cnt;
324 struct ti_hecc_priv *priv = netdev_priv(ndev);
325
326 netdev_dbg(ndev, "resetting hecc ...\n");
327 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
328
329 /* Set change control request and wait till enabled */
330 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
331
332 /*
333 * INFO: It has been observed that at times CCE bit may not be
334 * set and hw seems to be ok even if this bit is not set so
335 * timing out with a timing of 1ms to respect the specs
336 */
337 cnt = HECC_CCE_WAIT_COUNT;
338 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
339 --cnt;
340 udelay(10);
341 }
342
343 /*
344 * Note: On HECC, BTC can be programmed only in initialization mode, so
345 * it is expected that the can bittiming parameters are set via ip
346 * utility before the device is opened
347 */
348 ti_hecc_set_btc(priv);
349
350 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
351 hecc_write(priv, HECC_CANMC, 0);
352
353 /*
354 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on
355 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
356 */
357
358 /*
359 * INFO: It has been observed that at times CCE bit may not be
360 * set and hw seems to be ok even if this bit is not set so
361 */
362 cnt = HECC_CCE_WAIT_COUNT;
363 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
364 --cnt;
365 udelay(10);
366 }
367
368 /* Enable TX and RX I/O Control pins */
369 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
370 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
371
372 /* Clear registers for clean operation */
373 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
374 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
375 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
376 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
377 hecc_write(priv, HECC_CANME, 0);
378 hecc_write(priv, HECC_CANMD, 0);
379
380 /* SCC compat mode NOT supported (and not needed too) */
381 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
382 }
383
384 static void ti_hecc_start(struct net_device *ndev)
385 {
386 struct ti_hecc_priv *priv = netdev_priv(ndev);
387 u32 cnt, mbxno, mbx_mask;
388
389 /* put HECC in initialization mode and set btc */
390 ti_hecc_reset(ndev);
391
392 priv->tx_head = priv->tx_tail = HECC_TX_MASK;
393 priv->rx_next = HECC_RX_FIRST_MBOX;
394
395 /* Enable local and global acceptance mask registers */
396 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
397
398 /* Prepare configured mailboxes to receive messages */
399 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
400 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
401 mbx_mask = BIT(mbxno);
402 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
403 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
404 hecc_write_lam(priv, mbxno, HECC_SET_REG);
405 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
406 hecc_set_bit(priv, HECC_CANME, mbx_mask);
407 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
408 }
409
410 /* Prevent message over-write & Enable interrupts */
411 hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
412 if (priv->int_line) {
413 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
414 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
415 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
416 } else {
417 hecc_write(priv, HECC_CANMIL, 0);
418 hecc_write(priv, HECC_CANGIM,
419 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
420 }
421 priv->can.state = CAN_STATE_ERROR_ACTIVE;
422 }
423
424 static void ti_hecc_stop(struct net_device *ndev)
425 {
426 struct ti_hecc_priv *priv = netdev_priv(ndev);
427
428 /* Disable interrupts and disable mailboxes */
429 hecc_write(priv, HECC_CANGIM, 0);
430 hecc_write(priv, HECC_CANMIM, 0);
431 hecc_write(priv, HECC_CANME, 0);
432 priv->can.state = CAN_STATE_STOPPED;
433 }
434
435 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
436 {
437 int ret = 0;
438
439 switch (mode) {
440 case CAN_MODE_START:
441 ti_hecc_start(ndev);
442 netif_wake_queue(ndev);
443 break;
444 default:
445 ret = -EOPNOTSUPP;
446 break;
447 }
448
449 return ret;
450 }
451
452 static int ti_hecc_get_berr_counter(const struct net_device *ndev,
453 struct can_berr_counter *bec)
454 {
455 struct ti_hecc_priv *priv = netdev_priv(ndev);
456
457 bec->txerr = hecc_read(priv, HECC_CANTEC);
458 bec->rxerr = hecc_read(priv, HECC_CANREC);
459
460 return 0;
461 }
462
463 /*
464 * ti_hecc_xmit: HECC Transmit
465 *
466 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
467 * priority of the mailbox for tranmission is dependent upon priority setting
468 * field in mailbox registers. The mailbox with highest value in priority field
469 * is transmitted first. Only when two mailboxes have the same value in
470 * priority field the highest numbered mailbox is transmitted first.
471 *
472 * To utilize the HECC priority feature as described above we start with the
473 * highest numbered mailbox with highest priority level and move on to the next
474 * mailbox with the same priority level and so on. Once we loop through all the
475 * transmit mailboxes we choose the next priority level (lower) and so on
476 * until we reach the lowest priority level on the lowest numbered mailbox
477 * when we stop transmission until all mailboxes are transmitted and then
478 * restart at highest numbered mailbox with highest priority.
479 *
480 * Two counters (head and tail) are used to track the next mailbox to transmit
481 * and to track the echo buffer for already transmitted mailbox. The queue
482 * is stopped when all the mailboxes are busy or when there is a priority
483 * value roll-over happens.
484 */
485 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
486 {
487 struct ti_hecc_priv *priv = netdev_priv(ndev);
488 struct can_frame *cf = (struct can_frame *)skb->data;
489 u32 mbxno, mbx_mask, data;
490 unsigned long flags;
491
492 if (can_dropped_invalid_skb(ndev, skb))
493 return NETDEV_TX_OK;
494
495 mbxno = get_tx_head_mb(priv);
496 mbx_mask = BIT(mbxno);
497 spin_lock_irqsave(&priv->mbx_lock, flags);
498 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
499 spin_unlock_irqrestore(&priv->mbx_lock, flags);
500 netif_stop_queue(ndev);
501 netdev_err(priv->ndev,
502 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
503 priv->tx_head, priv->tx_tail);
504 return NETDEV_TX_BUSY;
505 }
506 spin_unlock_irqrestore(&priv->mbx_lock, flags);
507
508 /* Prepare mailbox for transmission */
509 data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
510 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
511 data |= HECC_CANMCF_RTR;
512 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
513
514 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
515 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
516 else /* Standard frame format */
517 data = (cf->can_id & CAN_SFF_MASK) << 18;
518 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
519 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
520 be32_to_cpu(*(__be32 *)(cf->data)));
521 if (cf->can_dlc > 4)
522 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
523 be32_to_cpu(*(__be32 *)(cf->data + 4)));
524 else
525 *(u32 *)(cf->data + 4) = 0;
526 can_put_echo_skb(skb, ndev, mbxno);
527
528 spin_lock_irqsave(&priv->mbx_lock, flags);
529 --priv->tx_head;
530 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
531 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
532 netif_stop_queue(ndev);
533 }
534 hecc_set_bit(priv, HECC_CANME, mbx_mask);
535 spin_unlock_irqrestore(&priv->mbx_lock, flags);
536
537 hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
538 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
539 hecc_write(priv, HECC_CANTRS, mbx_mask);
540
541 return NETDEV_TX_OK;
542 }
543
544 static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
545 {
546 struct net_device_stats *stats = &priv->ndev->stats;
547 struct can_frame *cf;
548 struct sk_buff *skb;
549 u32 data, mbx_mask;
550 unsigned long flags;
551
552 skb = alloc_can_skb(priv->ndev, &cf);
553 if (!skb) {
554 if (printk_ratelimit())
555 netdev_err(priv->ndev,
556 "ti_hecc_rx_pkt: alloc_can_skb() failed\n");
557 return -ENOMEM;
558 }
559
560 mbx_mask = BIT(mbxno);
561 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
562 if (data & HECC_CANMID_IDE)
563 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
564 else
565 cf->can_id = (data >> 18) & CAN_SFF_MASK;
566 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
567 if (data & HECC_CANMCF_RTR)
568 cf->can_id |= CAN_RTR_FLAG;
569 cf->can_dlc = get_can_dlc(data & 0xF);
570 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
571 *(__be32 *)(cf->data) = cpu_to_be32(data);
572 if (cf->can_dlc > 4) {
573 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
574 *(__be32 *)(cf->data + 4) = cpu_to_be32(data);
575 }
576 spin_lock_irqsave(&priv->mbx_lock, flags);
577 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
578 hecc_write(priv, HECC_CANRMP, mbx_mask);
579 /* enable mailbox only if it is part of rx buffer mailboxes */
580 if (priv->rx_next < HECC_RX_BUFFER_MBOX)
581 hecc_set_bit(priv, HECC_CANME, mbx_mask);
582 spin_unlock_irqrestore(&priv->mbx_lock, flags);
583
584 stats->rx_bytes += cf->can_dlc;
585 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
586 netif_receive_skb(skb);
587 stats->rx_packets++;
588
589 return 0;
590 }
591
592 /*
593 * ti_hecc_rx_poll - HECC receive pkts
594 *
595 * The receive mailboxes start from highest numbered mailbox till last xmit
596 * mailbox. On CAN frame reception the hardware places the data into highest
597 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
598 * have same filtering (ALL CAN frames) packets will arrive in the highest
599 * available RX mailbox and we need to ensure in-order packet reception.
600 *
601 * To ensure the packets are received in the right order we logically divide
602 * the RX mailboxes into main and buffer mailboxes. Packets are received as per
603 * mailbox priotity (higher to lower) in the main bank and once it is full we
604 * disable further reception into main mailboxes. While the main mailboxes are
605 * processed in NAPI, further packets are received in buffer mailboxes.
606 *
607 * We maintain a RX next mailbox counter to process packets and once all main
608 * mailboxe packets are passed to the upper stack we enable all of them but
609 * continue to process packets received in buffer mailboxes. With each packet
610 * received from buffer mailbox we enable it immediately so as to handle the
611 * overflow from higher mailboxes.
612 */
613 static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
614 {
615 struct net_device *ndev = napi->dev;
616 struct ti_hecc_priv *priv = netdev_priv(ndev);
617 u32 num_pkts = 0;
618 u32 mbx_mask;
619 unsigned long pending_pkts, flags;
620
621 if (!netif_running(ndev))
622 return 0;
623
624 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
625 num_pkts < quota) {
626 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
627 if (mbx_mask & pending_pkts) {
628 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
629 return num_pkts;
630 ++num_pkts;
631 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
632 break; /* pkt not received yet */
633 }
634 --priv->rx_next;
635 if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
636 /* enable high bank mailboxes */
637 spin_lock_irqsave(&priv->mbx_lock, flags);
638 mbx_mask = hecc_read(priv, HECC_CANME);
639 mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
640 hecc_write(priv, HECC_CANME, mbx_mask);
641 spin_unlock_irqrestore(&priv->mbx_lock, flags);
642 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
643 priv->rx_next = HECC_RX_FIRST_MBOX;
644 break;
645 }
646 }
647
648 /* Enable packet interrupt if all pkts are handled */
649 if (hecc_read(priv, HECC_CANRMP) == 0) {
650 napi_complete(napi);
651 /* Re-enable RX mailbox interrupts */
652 mbx_mask = hecc_read(priv, HECC_CANMIM);
653 mbx_mask |= HECC_TX_MBOX_MASK;
654 hecc_write(priv, HECC_CANMIM, mbx_mask);
655 }
656
657 return num_pkts;
658 }
659
660 static int ti_hecc_error(struct net_device *ndev, int int_status,
661 int err_status)
662 {
663 struct ti_hecc_priv *priv = netdev_priv(ndev);
664 struct net_device_stats *stats = &ndev->stats;
665 struct can_frame *cf;
666 struct sk_buff *skb;
667
668 /* propagate the error condition to the can stack */
669 skb = alloc_can_err_skb(ndev, &cf);
670 if (!skb) {
671 if (printk_ratelimit())
672 netdev_err(priv->ndev,
673 "ti_hecc_error: alloc_can_err_skb() failed\n");
674 return -ENOMEM;
675 }
676
677 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
678 if ((int_status & HECC_CANGIF_BOIF) == 0) {
679 priv->can.state = CAN_STATE_ERROR_WARNING;
680 ++priv->can.can_stats.error_warning;
681 cf->can_id |= CAN_ERR_CRTL;
682 if (hecc_read(priv, HECC_CANTEC) > 96)
683 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
684 if (hecc_read(priv, HECC_CANREC) > 96)
685 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
686 }
687 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
688 netdev_dbg(priv->ndev, "Error Warning interrupt\n");
689 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
690 }
691
692 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
693 if ((int_status & HECC_CANGIF_BOIF) == 0) {
694 priv->can.state = CAN_STATE_ERROR_PASSIVE;
695 ++priv->can.can_stats.error_passive;
696 cf->can_id |= CAN_ERR_CRTL;
697 if (hecc_read(priv, HECC_CANTEC) > 127)
698 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
699 if (hecc_read(priv, HECC_CANREC) > 127)
700 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
701 }
702 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
703 netdev_dbg(priv->ndev, "Error passive interrupt\n");
704 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
705 }
706
707 /*
708 * Need to check busoff condition in error status register too to
709 * ensure warning interrupts don't hog the system
710 */
711 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
712 priv->can.state = CAN_STATE_BUS_OFF;
713 cf->can_id |= CAN_ERR_BUSOFF;
714 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
715 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
716 /* Disable all interrupts in bus-off to avoid int hog */
717 hecc_write(priv, HECC_CANGIM, 0);
718 ++priv->can.can_stats.bus_off;
719 can_bus_off(ndev);
720 }
721
722 if (err_status & HECC_BUS_ERROR) {
723 ++priv->can.can_stats.bus_error;
724 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
725 if (err_status & HECC_CANES_FE) {
726 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
727 cf->data[2] |= CAN_ERR_PROT_FORM;
728 }
729 if (err_status & HECC_CANES_BE) {
730 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
731 cf->data[2] |= CAN_ERR_PROT_BIT;
732 }
733 if (err_status & HECC_CANES_SE) {
734 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
735 cf->data[2] |= CAN_ERR_PROT_STUFF;
736 }
737 if (err_status & HECC_CANES_CRCE) {
738 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
739 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
740 }
741 if (err_status & HECC_CANES_ACKE) {
742 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
743 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
744 }
745 }
746
747 stats->rx_packets++;
748 stats->rx_bytes += cf->can_dlc;
749 netif_rx(skb);
750
751 return 0;
752 }
753
754 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
755 {
756 struct net_device *ndev = (struct net_device *)dev_id;
757 struct ti_hecc_priv *priv = netdev_priv(ndev);
758 struct net_device_stats *stats = &ndev->stats;
759 u32 mbxno, mbx_mask, int_status, err_status;
760 unsigned long ack, flags;
761
762 int_status = hecc_read(priv,
763 (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0);
764
765 if (!int_status)
766 return IRQ_NONE;
767
768 err_status = hecc_read(priv, HECC_CANES);
769 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
770 HECC_CANES_EP | HECC_CANES_EW))
771 ti_hecc_error(ndev, int_status, err_status);
772
773 if (int_status & HECC_CANGIF_GMIF) {
774 while (priv->tx_tail - priv->tx_head > 0) {
775 mbxno = get_tx_tail_mb(priv);
776 mbx_mask = BIT(mbxno);
777 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
778 break;
779 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
780 hecc_write(priv, HECC_CANTA, mbx_mask);
781 spin_lock_irqsave(&priv->mbx_lock, flags);
782 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
783 spin_unlock_irqrestore(&priv->mbx_lock, flags);
784 stats->tx_bytes += hecc_read_mbx(priv, mbxno,
785 HECC_CANMCF) & 0xF;
786 stats->tx_packets++;
787 can_led_event(ndev, CAN_LED_EVENT_TX);
788 can_get_echo_skb(ndev, mbxno);
789 --priv->tx_tail;
790 }
791
792 /* restart queue if wrap-up or if queue stalled on last pkt */
793 if (((priv->tx_head == priv->tx_tail) &&
794 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
795 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
796 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
797 netif_wake_queue(ndev);
798
799 /* Disable RX mailbox interrupts and let NAPI reenable them */
800 if (hecc_read(priv, HECC_CANRMP)) {
801 ack = hecc_read(priv, HECC_CANMIM);
802 ack &= BIT(HECC_MAX_TX_MBOX) - 1;
803 hecc_write(priv, HECC_CANMIM, ack);
804 napi_schedule(&priv->napi);
805 }
806 }
807
808 /* clear all interrupt conditions - read back to avoid spurious ints */
809 if (priv->int_line) {
810 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
811 int_status = hecc_read(priv, HECC_CANGIF1);
812 } else {
813 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
814 int_status = hecc_read(priv, HECC_CANGIF0);
815 }
816
817 return IRQ_HANDLED;
818 }
819
820 static int ti_hecc_open(struct net_device *ndev)
821 {
822 struct ti_hecc_priv *priv = netdev_priv(ndev);
823 int err;
824
825 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
826 ndev->name, ndev);
827 if (err) {
828 netdev_err(ndev, "error requesting interrupt\n");
829 return err;
830 }
831
832 ti_hecc_transceiver_switch(priv, 1);
833
834 /* Open common can device */
835 err = open_candev(ndev);
836 if (err) {
837 netdev_err(ndev, "open_candev() failed %d\n", err);
838 ti_hecc_transceiver_switch(priv, 0);
839 free_irq(ndev->irq, ndev);
840 return err;
841 }
842
843 can_led_event(ndev, CAN_LED_EVENT_OPEN);
844
845 ti_hecc_start(ndev);
846 napi_enable(&priv->napi);
847 netif_start_queue(ndev);
848
849 return 0;
850 }
851
852 static int ti_hecc_close(struct net_device *ndev)
853 {
854 struct ti_hecc_priv *priv = netdev_priv(ndev);
855
856 netif_stop_queue(ndev);
857 napi_disable(&priv->napi);
858 ti_hecc_stop(ndev);
859 free_irq(ndev->irq, ndev);
860 close_candev(ndev);
861 ti_hecc_transceiver_switch(priv, 0);
862
863 can_led_event(ndev, CAN_LED_EVENT_STOP);
864
865 return 0;
866 }
867
868 static const struct net_device_ops ti_hecc_netdev_ops = {
869 .ndo_open = ti_hecc_open,
870 .ndo_stop = ti_hecc_close,
871 .ndo_start_xmit = ti_hecc_xmit,
872 .ndo_change_mtu = can_change_mtu,
873 };
874
875 static int ti_hecc_probe(struct platform_device *pdev)
876 {
877 struct net_device *ndev = (struct net_device *)0;
878 struct ti_hecc_priv *priv;
879 struct ti_hecc_platform_data *pdata;
880 struct resource *mem, *irq;
881 void __iomem *addr;
882 int err = -ENODEV;
883
884 pdata = dev_get_platdata(&pdev->dev);
885 if (!pdata) {
886 dev_err(&pdev->dev, "No platform data\n");
887 goto probe_exit;
888 }
889
890 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
891 if (!mem) {
892 dev_err(&pdev->dev, "No mem resources\n");
893 goto probe_exit;
894 }
895 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
896 if (!irq) {
897 dev_err(&pdev->dev, "No irq resource\n");
898 goto probe_exit;
899 }
900 if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) {
901 dev_err(&pdev->dev, "HECC region already claimed\n");
902 err = -EBUSY;
903 goto probe_exit;
904 }
905 addr = ioremap(mem->start, resource_size(mem));
906 if (!addr) {
907 dev_err(&pdev->dev, "ioremap failed\n");
908 err = -ENOMEM;
909 goto probe_exit_free_region;
910 }
911
912 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
913 if (!ndev) {
914 dev_err(&pdev->dev, "alloc_candev failed\n");
915 err = -ENOMEM;
916 goto probe_exit_iounmap;
917 }
918
919 priv = netdev_priv(ndev);
920 priv->ndev = ndev;
921 priv->base = addr;
922 priv->scc_ram_offset = pdata->scc_ram_offset;
923 priv->hecc_ram_offset = pdata->hecc_ram_offset;
924 priv->mbx_offset = pdata->mbx_offset;
925 priv->int_line = pdata->int_line;
926 priv->transceiver_switch = pdata->transceiver_switch;
927
928 priv->can.bittiming_const = &ti_hecc_bittiming_const;
929 priv->can.do_set_mode = ti_hecc_do_set_mode;
930 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
931 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
932
933 spin_lock_init(&priv->mbx_lock);
934 ndev->irq = irq->start;
935 ndev->flags |= IFF_ECHO;
936 platform_set_drvdata(pdev, ndev);
937 SET_NETDEV_DEV(ndev, &pdev->dev);
938 ndev->netdev_ops = &ti_hecc_netdev_ops;
939
940 priv->clk = clk_get(&pdev->dev, "hecc_ck");
941 if (IS_ERR(priv->clk)) {
942 dev_err(&pdev->dev, "No clock available\n");
943 err = PTR_ERR(priv->clk);
944 priv->clk = NULL;
945 goto probe_exit_candev;
946 }
947 priv->can.clock.freq = clk_get_rate(priv->clk);
948 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
949 HECC_DEF_NAPI_WEIGHT);
950
951 err = clk_prepare_enable(priv->clk);
952 if (err) {
953 dev_err(&pdev->dev, "clk_prepare_enable() failed\n");
954 goto probe_exit_clk;
955 }
956
957 err = register_candev(ndev);
958 if (err) {
959 dev_err(&pdev->dev, "register_candev() failed\n");
960 goto probe_exit_clk;
961 }
962
963 devm_can_led_init(ndev);
964
965 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
966 priv->base, (u32) ndev->irq);
967
968 return 0;
969
970 probe_exit_clk:
971 clk_put(priv->clk);
972 probe_exit_candev:
973 free_candev(ndev);
974 probe_exit_iounmap:
975 iounmap(addr);
976 probe_exit_free_region:
977 release_mem_region(mem->start, resource_size(mem));
978 probe_exit:
979 return err;
980 }
981
982 static int ti_hecc_remove(struct platform_device *pdev)
983 {
984 struct resource *res;
985 struct net_device *ndev = platform_get_drvdata(pdev);
986 struct ti_hecc_priv *priv = netdev_priv(ndev);
987
988 unregister_candev(ndev);
989 clk_disable_unprepare(priv->clk);
990 clk_put(priv->clk);
991 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
992 iounmap(priv->base);
993 release_mem_region(res->start, resource_size(res));
994 free_candev(ndev);
995
996 return 0;
997 }
998
999
1000 #ifdef CONFIG_PM
1001 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
1002 {
1003 struct net_device *dev = platform_get_drvdata(pdev);
1004 struct ti_hecc_priv *priv = netdev_priv(dev);
1005
1006 if (netif_running(dev)) {
1007 netif_stop_queue(dev);
1008 netif_device_detach(dev);
1009 }
1010
1011 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1012 priv->can.state = CAN_STATE_SLEEPING;
1013
1014 clk_disable_unprepare(priv->clk);
1015
1016 return 0;
1017 }
1018
1019 static int ti_hecc_resume(struct platform_device *pdev)
1020 {
1021 struct net_device *dev = platform_get_drvdata(pdev);
1022 struct ti_hecc_priv *priv = netdev_priv(dev);
1023 int err;
1024
1025 err = clk_prepare_enable(priv->clk);
1026 if (err)
1027 return err;
1028
1029 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1030 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1031
1032 if (netif_running(dev)) {
1033 netif_device_attach(dev);
1034 netif_start_queue(dev);
1035 }
1036
1037 return 0;
1038 }
1039 #else
1040 #define ti_hecc_suspend NULL
1041 #define ti_hecc_resume NULL
1042 #endif
1043
1044 /* TI HECC netdevice driver: platform driver structure */
1045 static struct platform_driver ti_hecc_driver = {
1046 .driver = {
1047 .name = DRV_NAME,
1048 },
1049 .probe = ti_hecc_probe,
1050 .remove = ti_hecc_remove,
1051 .suspend = ti_hecc_suspend,
1052 .resume = ti_hecc_resume,
1053 };
1054
1055 module_platform_driver(ti_hecc_driver);
1056
1057 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1058 MODULE_LICENSE("GPL v2");
1059 MODULE_DESCRIPTION(DRV_DESC);
1060 MODULE_ALIAS("platform:" DRV_NAME);
Linux with added FPC-III support