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OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / net / can / ti_hecc.c
blob5a2e1e3588a194a387660c0dd8715f5eb27fc39f
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/init.h>
41 #include <linux/kernel.h>
42 #include <linux/types.h>
43 #include <linux/interrupt.h>
44 #include <linux/errno.h>
45 #include <linux/netdevice.h>
46 #include <linux/skbuff.h>
47 #include <linux/platform_device.h>
48 #include <linux/clk.h>
49 #include <linux/io.h>
50
51 #include <linux/can/dev.h>
52 #include <linux/can/error.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 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_get_state(const struct net_device *ndev,
289 enum can_state *state)
290 {
291 struct ti_hecc_priv *priv = netdev_priv(ndev);
292
293 *state = priv->can.state;
294 return 0;
295 }
296
297 static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
298 {
299 struct can_bittiming *bit_timing = &priv->can.bittiming;
300 u32 can_btc;
301
302 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
303 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
304 & 0xF) << 3;
305 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
306 if (bit_timing->brp > 4)
307 can_btc |= HECC_CANBTC_SAM;
308 else
309 dev_warn(priv->ndev->dev.parent, "WARN: Triple" \
310 "sampling not set due to h/w limitations");
311 }
312 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
313 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
314
315 /* ERM being set to 0 by default meaning resync at falling edge */
316
317 hecc_write(priv, HECC_CANBTC, can_btc);
318 dev_info(priv->ndev->dev.parent, "setting CANBTC=%#x\n", can_btc);
319
320 return 0;
321 }
322
323 static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
324 int on)
325 {
326 if (priv->transceiver_switch)
327 priv->transceiver_switch(on);
328 }
329
330 static void ti_hecc_reset(struct net_device *ndev)
331 {
332 u32 cnt;
333 struct ti_hecc_priv *priv = netdev_priv(ndev);
334
335 dev_dbg(ndev->dev.parent, "resetting hecc ...\n");
336 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
337
338 /* Set change control request and wait till enabled */
339 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
340
341 /*
342 * INFO: It has been observed that at times CCE bit may not be
343 * set and hw seems to be ok even if this bit is not set so
344 * timing out with a timing of 1ms to respect the specs
345 */
346 cnt = HECC_CCE_WAIT_COUNT;
347 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
348 --cnt;
349 udelay(10);
350 }
351
352 /*
353 * Note: On HECC, BTC can be programmed only in initialization mode, so
354 * it is expected that the can bittiming parameters are set via ip
355 * utility before the device is opened
356 */
357 ti_hecc_set_btc(priv);
358
359 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
360 hecc_write(priv, HECC_CANMC, 0);
361
362 /*
363 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on
364 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
365 */
366
367 /*
368 * INFO: It has been observed that at times CCE bit may not be
369 * set and hw seems to be ok even if this bit is not set so
370 */
371 cnt = HECC_CCE_WAIT_COUNT;
372 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
373 --cnt;
374 udelay(10);
375 }
376
377 /* Enable TX and RX I/O Control pins */
378 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
379 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
380
381 /* Clear registers for clean operation */
382 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
383 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
384 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
385 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
386 hecc_write(priv, HECC_CANME, 0);
387 hecc_write(priv, HECC_CANMD, 0);
388
389 /* SCC compat mode NOT supported (and not needed too) */
390 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
391 }
392
393 static void ti_hecc_start(struct net_device *ndev)
394 {
395 struct ti_hecc_priv *priv = netdev_priv(ndev);
396 u32 cnt, mbxno, mbx_mask;
397
398 /* put HECC in initialization mode and set btc */
399 ti_hecc_reset(ndev);
400
401 priv->tx_head = priv->tx_tail = HECC_TX_MASK;
402 priv->rx_next = HECC_RX_FIRST_MBOX;
403
404 /* Enable local and global acceptance mask registers */
405 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
406
407 /* Prepare configured mailboxes to receive messages */
408 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
409 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
410 mbx_mask = BIT(mbxno);
411 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
412 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
413 hecc_write_lam(priv, mbxno, HECC_SET_REG);
414 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
415 hecc_set_bit(priv, HECC_CANME, mbx_mask);
416 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
417 }
418
419 /* Prevent message over-write & Enable interrupts */
420 hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
421 if (priv->int_line) {
422 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
423 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
424 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
425 } else {
426 hecc_write(priv, HECC_CANMIL, 0);
427 hecc_write(priv, HECC_CANGIM,
428 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
429 }
430 priv->can.state = CAN_STATE_ERROR_ACTIVE;
431 }
432
433 static void ti_hecc_stop(struct net_device *ndev)
434 {
435 struct ti_hecc_priv *priv = netdev_priv(ndev);
436
437 /* Disable interrupts and disable mailboxes */
438 hecc_write(priv, HECC_CANGIM, 0);
439 hecc_write(priv, HECC_CANMIM, 0);
440 hecc_write(priv, HECC_CANME, 0);
441 priv->can.state = CAN_STATE_STOPPED;
442 }
443
444 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
445 {
446 int ret = 0;
447
448 switch (mode) {
449 case CAN_MODE_START:
450 ti_hecc_start(ndev);
451 netif_wake_queue(ndev);
452 break;
453 default:
454 ret = -EOPNOTSUPP;
455 break;
456 }
457
458 return ret;
459 }
460
461 /*
462 * ti_hecc_xmit: HECC Transmit
463 *
464 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
465 * priority of the mailbox for tranmission is dependent upon priority setting
466 * field in mailbox registers. The mailbox with highest value in priority field
467 * is transmitted first. Only when two mailboxes have the same value in
468 * priority field the highest numbered mailbox is transmitted first.
469 *
470 * To utilize the HECC priority feature as described above we start with the
471 * highest numbered mailbox with highest priority level and move on to the next
472 * mailbox with the same priority level and so on. Once we loop through all the
473 * transmit mailboxes we choose the next priority level (lower) and so on
474 * until we reach the lowest priority level on the lowest numbered mailbox
475 * when we stop transmission until all mailboxes are transmitted and then
476 * restart at highest numbered mailbox with highest priority.
477 *
478 * Two counters (head and tail) are used to track the next mailbox to transmit
479 * and to track the echo buffer for already transmitted mailbox. The queue
480 * is stopped when all the mailboxes are busy or when there is a priority
481 * value roll-over happens.
482 */
483 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
484 {
485 struct ti_hecc_priv *priv = netdev_priv(ndev);
486 struct can_frame *cf = (struct can_frame *)skb->data;
487 u32 mbxno, mbx_mask, data;
488 unsigned long flags;
489
490 if (can_dropped_invalid_skb(ndev, skb))
491 return NETDEV_TX_OK;
492
493 mbxno = get_tx_head_mb(priv);
494 mbx_mask = BIT(mbxno);
495 spin_lock_irqsave(&priv->mbx_lock, flags);
496 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
497 spin_unlock_irqrestore(&priv->mbx_lock, flags);
498 netif_stop_queue(ndev);
499 dev_err(priv->ndev->dev.parent,
500 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
501 priv->tx_head, priv->tx_tail);
502 return NETDEV_TX_BUSY;
503 }
504 spin_unlock_irqrestore(&priv->mbx_lock, flags);
505
506 /* Prepare mailbox for transmission */
507 data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
508 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
509 data |= HECC_CANMCF_RTR;
510 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
511
512 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
513 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
514 else /* Standard frame format */
515 data = (cf->can_id & CAN_SFF_MASK) << 18;
516 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
517 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
518 be32_to_cpu(*(u32 *)(cf->data)));
519 if (cf->can_dlc > 4)
520 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
521 be32_to_cpu(*(u32 *)(cf->data + 4)));
522 else
523 *(u32 *)(cf->data + 4) = 0;
524 can_put_echo_skb(skb, ndev, mbxno);
525
526 spin_lock_irqsave(&priv->mbx_lock, flags);
527 --priv->tx_head;
528 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
529 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
530 netif_stop_queue(ndev);
531 }
532 hecc_set_bit(priv, HECC_CANME, mbx_mask);
533 spin_unlock_irqrestore(&priv->mbx_lock, flags);
534
535 hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
536 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
537 hecc_write(priv, HECC_CANTRS, mbx_mask);
538
539 return NETDEV_TX_OK;
540 }
541
542 static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
543 {
544 struct net_device_stats *stats = &priv->ndev->stats;
545 struct can_frame *cf;
546 struct sk_buff *skb;
547 u32 data, mbx_mask;
548 unsigned long flags;
549
550 skb = alloc_can_skb(priv->ndev, &cf);
551 if (!skb) {
552 if (printk_ratelimit())
553 dev_err(priv->ndev->dev.parent,
554 "ti_hecc_rx_pkt: alloc_can_skb() failed\n");
555 return -ENOMEM;
556 }
557
558 mbx_mask = BIT(mbxno);
559 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
560 if (data & HECC_CANMID_IDE)
561 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
562 else
563 cf->can_id = (data >> 18) & CAN_SFF_MASK;
564 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
565 if (data & HECC_CANMCF_RTR)
566 cf->can_id |= CAN_RTR_FLAG;
567 cf->can_dlc = get_can_dlc(data & 0xF);
568 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
569 *(u32 *)(cf->data) = cpu_to_be32(data);
570 if (cf->can_dlc > 4) {
571 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
572 *(u32 *)(cf->data + 4) = cpu_to_be32(data);
573 } else {
574 *(u32 *)(cf->data + 4) = 0;
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 netif_receive_skb(skb);
586 stats->rx_packets++;
587
588 return 0;
589 }
590
591 /*
592 * ti_hecc_rx_poll - HECC receive pkts
593 *
594 * The receive mailboxes start from highest numbered mailbox till last xmit
595 * mailbox. On CAN frame reception the hardware places the data into highest
596 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
597 * have same filtering (ALL CAN frames) packets will arrive in the highest
598 * available RX mailbox and we need to ensure in-order packet reception.
599 *
600 * To ensure the packets are received in the right order we logically divide
601 * the RX mailboxes into main and buffer mailboxes. Packets are received as per
602 * mailbox priotity (higher to lower) in the main bank and once it is full we
603 * disable further reception into main mailboxes. While the main mailboxes are
604 * processed in NAPI, further packets are received in buffer mailboxes.
605 *
606 * We maintain a RX next mailbox counter to process packets and once all main
607 * mailboxe packets are passed to the upper stack we enable all of them but
608 * continue to process packets received in buffer mailboxes. With each packet
609 * received from buffer mailbox we enable it immediately so as to handle the
610 * overflow from higher mailboxes.
611 */
612 static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
613 {
614 struct net_device *ndev = napi->dev;
615 struct ti_hecc_priv *priv = netdev_priv(ndev);
616 u32 num_pkts = 0;
617 u32 mbx_mask;
618 unsigned long pending_pkts, flags;
619
620 if (!netif_running(ndev))
621 return 0;
622
623 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
624 num_pkts < quota) {
625 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
626 if (mbx_mask & pending_pkts) {
627 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
628 return num_pkts;
629 ++num_pkts;
630 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
631 break; /* pkt not received yet */
632 }
633 --priv->rx_next;
634 if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
635 /* enable high bank mailboxes */
636 spin_lock_irqsave(&priv->mbx_lock, flags);
637 mbx_mask = hecc_read(priv, HECC_CANME);
638 mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
639 hecc_write(priv, HECC_CANME, mbx_mask);
640 spin_unlock_irqrestore(&priv->mbx_lock, flags);
641 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
642 priv->rx_next = HECC_RX_FIRST_MBOX;
643 break;
644 }
645 }
646
647 /* Enable packet interrupt if all pkts are handled */
648 if (hecc_read(priv, HECC_CANRMP) == 0) {
649 napi_complete(napi);
650 /* Re-enable RX mailbox interrupts */
651 mbx_mask = hecc_read(priv, HECC_CANMIM);
652 mbx_mask |= HECC_TX_MBOX_MASK;
653 hecc_write(priv, HECC_CANMIM, mbx_mask);
654 }
655
656 return num_pkts;
657 }
658
659 static int ti_hecc_error(struct net_device *ndev, int int_status,
660 int err_status)
661 {
662 struct ti_hecc_priv *priv = netdev_priv(ndev);
663 struct net_device_stats *stats = &ndev->stats;
664 struct can_frame *cf;
665 struct sk_buff *skb;
666
667 /* propagate the error condition to the can stack */
668 skb = alloc_can_err_skb(ndev, &cf);
669 if (!skb) {
670 if (printk_ratelimit())
671 dev_err(priv->ndev->dev.parent,
672 "ti_hecc_error: alloc_can_err_skb() failed\n");
673 return -ENOMEM;
674 }
675
676 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
677 if ((int_status & HECC_CANGIF_BOIF) == 0) {
678 priv->can.state = CAN_STATE_ERROR_WARNING;
679 ++priv->can.can_stats.error_warning;
680 cf->can_id |= CAN_ERR_CRTL;
681 if (hecc_read(priv, HECC_CANTEC) > 96)
682 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
683 if (hecc_read(priv, HECC_CANREC) > 96)
684 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
685 }
686 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
687 dev_dbg(priv->ndev->dev.parent, "Error Warning interrupt\n");
688 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
689 }
690
691 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
692 if ((int_status & HECC_CANGIF_BOIF) == 0) {
693 priv->can.state = CAN_STATE_ERROR_PASSIVE;
694 ++priv->can.can_stats.error_passive;
695 cf->can_id |= CAN_ERR_CRTL;
696 if (hecc_read(priv, HECC_CANTEC) > 127)
697 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
698 if (hecc_read(priv, HECC_CANREC) > 127)
699 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
700 }
701 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
702 dev_dbg(priv->ndev->dev.parent, "Error passive interrupt\n");
703 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
704 }
705
706 /*
707 * Need to check busoff condition in error status register too to
708 * ensure warning interrupts don't hog the system
709 */
710 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
711 priv->can.state = CAN_STATE_BUS_OFF;
712 cf->can_id |= CAN_ERR_BUSOFF;
713 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
714 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
715 /* Disable all interrupts in bus-off to avoid int hog */
716 hecc_write(priv, HECC_CANGIM, 0);
717 can_bus_off(ndev);
718 }
719
720 if (err_status & HECC_BUS_ERROR) {
721 ++priv->can.can_stats.bus_error;
722 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
723 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
724 if (err_status & HECC_CANES_FE) {
725 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
726 cf->data[2] |= CAN_ERR_PROT_FORM;
727 }
728 if (err_status & HECC_CANES_BE) {
729 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
730 cf->data[2] |= CAN_ERR_PROT_BIT;
731 }
732 if (err_status & HECC_CANES_SE) {
733 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
734 cf->data[2] |= CAN_ERR_PROT_STUFF;
735 }
736 if (err_status & HECC_CANES_CRCE) {
737 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
738 cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
739 CAN_ERR_PROT_LOC_CRC_DEL;
740 }
741 if (err_status & HECC_CANES_ACKE) {
742 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
743 cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
744 CAN_ERR_PROT_LOC_ACK_DEL;
745 }
746 }
747
748 netif_rx(skb);
749 stats->rx_packets++;
750 stats->rx_bytes += cf->can_dlc;
751
752 return 0;
753 }
754
755 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
756 {
757 struct net_device *ndev = (struct net_device *)dev_id;
758 struct ti_hecc_priv *priv = netdev_priv(ndev);
759 struct net_device_stats *stats = &ndev->stats;
760 u32 mbxno, mbx_mask, int_status, err_status;
761 unsigned long ack, flags;
762
763 int_status = hecc_read(priv,
764 (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0);
765
766 if (!int_status)
767 return IRQ_NONE;
768
769 err_status = hecc_read(priv, HECC_CANES);
770 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
771 HECC_CANES_EP | HECC_CANES_EW))
772 ti_hecc_error(ndev, int_status, err_status);
773
774 if (int_status & HECC_CANGIF_GMIF) {
775 while (priv->tx_tail - priv->tx_head > 0) {
776 mbxno = get_tx_tail_mb(priv);
777 mbx_mask = BIT(mbxno);
778 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
779 break;
780 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
781 hecc_write(priv, HECC_CANTA, mbx_mask);
782 spin_lock_irqsave(&priv->mbx_lock, flags);
783 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
784 spin_unlock_irqrestore(&priv->mbx_lock, flags);
785 stats->tx_bytes += hecc_read_mbx(priv, mbxno,
786 HECC_CANMCF) & 0xF;
787 stats->tx_packets++;
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 dev_err(ndev->dev.parent, "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 dev_err(ndev->dev.parent, "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 ti_hecc_start(ndev);
844 napi_enable(&priv->napi);
845 netif_start_queue(ndev);
846
847 return 0;
848 }
849
850 static int ti_hecc_close(struct net_device *ndev)
851 {
852 struct ti_hecc_priv *priv = netdev_priv(ndev);
853
854 netif_stop_queue(ndev);
855 napi_disable(&priv->napi);
856 ti_hecc_stop(ndev);
857 free_irq(ndev->irq, ndev);
858 close_candev(ndev);
859 ti_hecc_transceiver_switch(priv, 0);
860
861 return 0;
862 }
863
864 static const struct net_device_ops ti_hecc_netdev_ops = {
865 .ndo_open = ti_hecc_open,
866 .ndo_stop = ti_hecc_close,
867 .ndo_start_xmit = ti_hecc_xmit,
868 };
869
870 static int ti_hecc_probe(struct platform_device *pdev)
871 {
872 struct net_device *ndev = (struct net_device *)0;
873 struct ti_hecc_priv *priv;
874 struct ti_hecc_platform_data *pdata;
875 struct resource *mem, *irq;
876 void __iomem *addr;
877 int err = -ENODEV;
878
879 pdata = pdev->dev.platform_data;
880 if (!pdata) {
881 dev_err(&pdev->dev, "No platform data\n");
882 goto probe_exit;
883 }
884
885 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
886 if (!mem) {
887 dev_err(&pdev->dev, "No mem resources\n");
888 goto probe_exit;
889 }
890 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
891 if (!irq) {
892 dev_err(&pdev->dev, "No irq resource\n");
893 goto probe_exit;
894 }
895 if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) {
896 dev_err(&pdev->dev, "HECC region already claimed\n");
897 err = -EBUSY;
898 goto probe_exit;
899 }
900 addr = ioremap(mem->start, resource_size(mem));
901 if (!addr) {
902 dev_err(&pdev->dev, "ioremap failed\n");
903 err = -ENOMEM;
904 goto probe_exit_free_region;
905 }
906
907 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
908 if (!ndev) {
909 dev_err(&pdev->dev, "alloc_candev failed\n");
910 err = -ENOMEM;
911 goto probe_exit_iounmap;
912 }
913
914 priv = netdev_priv(ndev);
915 priv->ndev = ndev;
916 priv->base = addr;
917 priv->scc_ram_offset = pdata->scc_ram_offset;
918 priv->hecc_ram_offset = pdata->hecc_ram_offset;
919 priv->mbx_offset = pdata->mbx_offset;
920 priv->int_line = pdata->int_line;
921 priv->transceiver_switch = pdata->transceiver_switch;
922
923 priv->can.bittiming_const = &ti_hecc_bittiming_const;
924 priv->can.do_set_mode = ti_hecc_do_set_mode;
925 priv->can.do_get_state = ti_hecc_get_state;
926 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
927
928 spin_lock_init(&priv->mbx_lock);
929 ndev->irq = irq->start;
930 ndev->flags |= IFF_ECHO;
931 platform_set_drvdata(pdev, ndev);
932 SET_NETDEV_DEV(ndev, &pdev->dev);
933 ndev->netdev_ops = &ti_hecc_netdev_ops;
934
935 priv->clk = clk_get(&pdev->dev, "hecc_ck");
936 if (IS_ERR(priv->clk)) {
937 dev_err(&pdev->dev, "No clock available\n");
938 err = PTR_ERR(priv->clk);
939 priv->clk = NULL;
940 goto probe_exit_candev;
941 }
942 priv->can.clock.freq = clk_get_rate(priv->clk);
943 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
944 HECC_DEF_NAPI_WEIGHT);
945
946 clk_enable(priv->clk);
947 err = register_candev(ndev);
948 if (err) {
949 dev_err(&pdev->dev, "register_candev() failed\n");
950 goto probe_exit_clk;
951 }
952 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
953 priv->base, (u32) ndev->irq);
954
955 return 0;
956
957 probe_exit_clk:
958 clk_put(priv->clk);
959 probe_exit_candev:
960 free_candev(ndev);
961 probe_exit_iounmap:
962 iounmap(addr);
963 probe_exit_free_region:
964 release_mem_region(mem->start, resource_size(mem));
965 probe_exit:
966 return err;
967 }
968
969 static int __devexit ti_hecc_remove(struct platform_device *pdev)
970 {
971 struct resource *res;
972 struct net_device *ndev = platform_get_drvdata(pdev);
973 struct ti_hecc_priv *priv = netdev_priv(ndev);
974
975 clk_disable(priv->clk);
976 clk_put(priv->clk);
977 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
978 iounmap(priv->base);
979 release_mem_region(res->start, resource_size(res));
980 unregister_candev(ndev);
981 free_candev(ndev);
982 platform_set_drvdata(pdev, NULL);
983
984 return 0;
985 }
986
987
988 #ifdef CONFIG_PM
989 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
990 {
991 struct net_device *dev = platform_get_drvdata(pdev);
992 struct ti_hecc_priv *priv = netdev_priv(dev);
993
994 if (netif_running(dev)) {
995 netif_stop_queue(dev);
996 netif_device_detach(dev);
997 }
998
999 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1000 priv->can.state = CAN_STATE_SLEEPING;
1001
1002 clk_disable(priv->clk);
1003
1004 return 0;
1005 }
1006
1007 static int ti_hecc_resume(struct platform_device *pdev)
1008 {
1009 struct net_device *dev = platform_get_drvdata(pdev);
1010 struct ti_hecc_priv *priv = netdev_priv(dev);
1011
1012 clk_enable(priv->clk);
1013
1014 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1015 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1016
1017 if (netif_running(dev)) {
1018 netif_device_attach(dev);
1019 netif_start_queue(dev);
1020 }
1021
1022 return 0;
1023 }
1024 #else
1025 #define ti_hecc_suspend NULL
1026 #define ti_hecc_resume NULL
1027 #endif
1028
1029 /* TI HECC netdevice driver: platform driver structure */
1030 static struct platform_driver ti_hecc_driver = {
1031 .driver = {
1032 .name = DRV_NAME,
1033 .owner = THIS_MODULE,
1034 },
1035 .probe = ti_hecc_probe,
1036 .remove = __devexit_p(ti_hecc_remove),
1037 .suspend = ti_hecc_suspend,
1038 .resume = ti_hecc_resume,
1039 };
1040
1041 module_platform_driver(ti_hecc_driver);
1042
1043 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1044 MODULE_LICENSE("GPL v2");
1045 MODULE_DESCRIPTION(DRV_DESC);