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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#include <linux/module.h>
21#include <linux/kernel.h>
22#include <linux/types.h>
23#include <linux/interrupt.h>
24#include <linux/errno.h>
25#include <linux/netdevice.h>
26#include <linux/skbuff.h>
27#include <linux/platform_device.h>
28#include <linux/clk.h>
29#include <linux/io.h>
30#include <linux/of.h>
31#include <linux/of_device.h>
32#include <linux/regulator/consumer.h>
33
34#include <linux/can/dev.h>
35#include <linux/can/error.h>
36#include <linux/can/led.h>
37
38#define DRV_NAME "ti_hecc"
39#define HECC_MODULE_VERSION "0.7"
40MODULE_VERSION(HECC_MODULE_VERSION);
41#define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
42
43/* TX / RX Mailbox Configuration */
44#define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
45#define MAX_TX_PRIO 0x3F /* hardware value - do not change */
46
47/*
48 * Important Note: TX mailbox configuration
49 * TX mailboxes should be restricted to the number of SKB buffers to avoid
50 * maintaining SKB buffers separately. TX mailboxes should be a power of 2
51 * for the mailbox logic to work. Top mailbox numbers are reserved for RX
52 * and lower mailboxes for TX.
53 *
54 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
55 * 4 (default) 2
56 * 8 3
57 * 16 4
58 */
59#define HECC_MB_TX_SHIFT 2 /* as per table above */
60#define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
61
62#define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
63#define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
64#define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
65#define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
66#define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1))
67#define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX
68
69/*
70 * Important Note: RX mailbox configuration
71 * RX mailboxes are further logically split into two - main and buffer
72 * mailboxes. The goal is to get all packets into main mailboxes as
73 * driven by mailbox number and receive priority (higher to lower) and
74 * buffer mailboxes are used to receive pkts while main mailboxes are being
75 * processed. This ensures in-order packet reception.
76 *
77 * Here are the recommended values for buffer mailbox. Note that RX mailboxes
78 * start after TX mailboxes:
79 *
80 * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes
81 * 28 12 8
82 * 16 20 4
83 */
84
85#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
86#define HECC_RX_BUFFER_MBOX 12 /* as per table above */
87#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
88#define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1))
89
90/* TI HECC module registers */
91#define HECC_CANME 0x0 /* Mailbox enable */
92#define HECC_CANMD 0x4 /* Mailbox direction */
93#define HECC_CANTRS 0x8 /* Transmit request set */
94#define HECC_CANTRR 0xC /* Transmit request */
95#define HECC_CANTA 0x10 /* Transmission acknowledge */
96#define HECC_CANAA 0x14 /* Abort acknowledge */
97#define HECC_CANRMP 0x18 /* Receive message pending */
98#define HECC_CANRML 0x1C /* Remote message lost */
99#define HECC_CANRFP 0x20 /* Remote frame pending */
100#define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
101#define HECC_CANMC 0x28 /* Master control */
102#define HECC_CANBTC 0x2C /* Bit timing configuration */
103#define HECC_CANES 0x30 /* Error and status */
104#define HECC_CANTEC 0x34 /* Transmit error counter */
105#define HECC_CANREC 0x38 /* Receive error counter */
106#define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
107#define HECC_CANGIM 0x40 /* Global interrupt mask */
108#define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
109#define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
110#define HECC_CANMIL 0x4C /* Mailbox interrupt level */
111#define HECC_CANOPC 0x50 /* Overwrite protection control */
112#define HECC_CANTIOC 0x54 /* Transmit I/O control */
113#define HECC_CANRIOC 0x58 /* Receive I/O control */
114#define HECC_CANLNT 0x5C /* HECC only: Local network time */
115#define HECC_CANTOC 0x60 /* HECC only: Time-out control */
116#define HECC_CANTOS 0x64 /* HECC only: Time-out status */
117#define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
118#define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
119
120/* Mailbox registers */
121#define HECC_CANMID 0x0
122#define HECC_CANMCF 0x4
123#define HECC_CANMDL 0x8
124#define HECC_CANMDH 0xC
125
126#define HECC_SET_REG 0xFFFFFFFF
127#define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
128#define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
129
130#define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
131#define HECC_CANMC_CCR BIT(12) /* Change config request */
132#define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
133#define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
134#define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
135#define HECC_CANMC_SRES BIT(5) /* Software reset */
136
137#define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
138#define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
139
140#define HECC_CANMID_IDE BIT(31) /* Extended frame format */
141#define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
142#define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
143
144#define HECC_CANES_FE BIT(24) /* form error */
145#define HECC_CANES_BE BIT(23) /* bit error */
146#define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
147#define HECC_CANES_CRCE BIT(21) /* CRC error */
148#define HECC_CANES_SE BIT(20) /* stuff bit error */
149#define HECC_CANES_ACKE BIT(19) /* ack error */
150#define HECC_CANES_BO BIT(18) /* Bus off status */
151#define HECC_CANES_EP BIT(17) /* Error passive status */
152#define HECC_CANES_EW BIT(16) /* Error warning status */
153#define HECC_CANES_SMA BIT(5) /* suspend mode ack */
154#define HECC_CANES_CCE BIT(4) /* Change config enabled */
155#define HECC_CANES_PDA BIT(3) /* Power down mode ack */
156
157#define HECC_CANBTC_SAM BIT(7) /* sample points */
158
159#define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
160 HECC_CANES_CRCE | HECC_CANES_SE |\
161 HECC_CANES_ACKE)
162
163#define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
164
165#define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
166#define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
167#define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
168#define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
169#define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
170#define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
171#define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
172#define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
173#define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
174#define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
175#define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
176#define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
177#define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
178#define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
179#define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
180
181/* CAN Bittiming constants as per HECC specs */
182static const struct can_bittiming_const ti_hecc_bittiming_const = {
183 .name = DRV_NAME,
184 .tseg1_min = 1,
185 .tseg1_max = 16,
186 .tseg2_min = 1,
187 .tseg2_max = 8,
188 .sjw_max = 4,
189 .brp_min = 1,
190 .brp_max = 256,
191 .brp_inc = 1,
192};
193
194struct ti_hecc_priv {
195 struct can_priv can; /* MUST be first member/field */
196 struct napi_struct napi;
197 struct net_device *ndev;
198 struct clk *clk;
199 void __iomem *base;
200 void __iomem *hecc_ram;
201 void __iomem *mbx;
202 bool use_hecc1int;
203 spinlock_t mbx_lock; /* CANME register needs protection */
204 u32 tx_head;
205 u32 tx_tail;
206 u32 rx_next;
207 struct regulator *reg_xceiver;
208};
209
210static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
211{
212 return priv->tx_head & HECC_TX_MB_MASK;
213}
214
215static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
216{
217 return priv->tx_tail & HECC_TX_MB_MASK;
218}
219
220static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
221{
222 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
223}
224
225static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
226{
227 __raw_writel(val, priv->hecc_ram + mbxno * 4);
228}
229
230static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
231 u32 reg, u32 val)
232{
233 __raw_writel(val, priv->mbx + mbxno * 0x10 + reg);
234}
235
236static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
237{
238 return __raw_readl(priv->mbx + mbxno * 0x10 + reg);
239}
240
241static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
242{
243 __raw_writel(val, priv->base + reg);
244}
245
246static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
247{
248 return __raw_readl(priv->base + reg);
249}
250
251static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
252 u32 bit_mask)
253{
254 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
255}
256
257static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
258 u32 bit_mask)
259{
260 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
261}
262
263static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
264{
265 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
266}
267
268static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
269{
270 struct can_bittiming *bit_timing = &priv->can.bittiming;
271 u32 can_btc;
272
273 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
274 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
275 & 0xF) << 3;
276 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
277 if (bit_timing->brp > 4)
278 can_btc |= HECC_CANBTC_SAM;
279 else
280 netdev_warn(priv->ndev, "WARN: Triple"
281 "sampling not set due to h/w limitations");
282 }
283 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
284 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
285
286 /* ERM being set to 0 by default meaning resync at falling edge */
287
288 hecc_write(priv, HECC_CANBTC, can_btc);
289 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
290
291 return 0;
292}
293
294static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
295 int on)
296{
297 if (!priv->reg_xceiver)
298 return 0;
299
300 if (on)
301 return regulator_enable(priv->reg_xceiver);
302 else
303 return regulator_disable(priv->reg_xceiver);
304}
305
306static void ti_hecc_reset(struct net_device *ndev)
307{
308 u32 cnt;
309 struct ti_hecc_priv *priv = netdev_priv(ndev);
310
311 netdev_dbg(ndev, "resetting hecc ...\n");
312 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
313
314 /* Set change control request and wait till enabled */
315 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
316
317 /*
318 * INFO: It has been observed that at times CCE bit may not be
319 * set and hw seems to be ok even if this bit is not set so
320 * timing out with a timing of 1ms to respect the specs
321 */
322 cnt = HECC_CCE_WAIT_COUNT;
323 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
324 --cnt;
325 udelay(10);
326 }
327
328 /*
329 * Note: On HECC, BTC can be programmed only in initialization mode, so
330 * it is expected that the can bittiming parameters are set via ip
331 * utility before the device is opened
332 */
333 ti_hecc_set_btc(priv);
334
335 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
336 hecc_write(priv, HECC_CANMC, 0);
337
338 /*
339 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on
340 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
341 */
342
343 /*
344 * INFO: It has been observed that at times CCE bit may not be
345 * set and hw seems to be ok even if this bit is not set so
346 */
347 cnt = HECC_CCE_WAIT_COUNT;
348 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
349 --cnt;
350 udelay(10);
351 }
352
353 /* Enable TX and RX I/O Control pins */
354 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
355 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
356
357 /* Clear registers for clean operation */
358 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
359 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
360 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
361 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
362 hecc_write(priv, HECC_CANME, 0);
363 hecc_write(priv, HECC_CANMD, 0);
364
365 /* SCC compat mode NOT supported (and not needed too) */
366 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
367}
368
369static void ti_hecc_start(struct net_device *ndev)
370{
371 struct ti_hecc_priv *priv = netdev_priv(ndev);
372 u32 cnt, mbxno, mbx_mask;
373
374 /* put HECC in initialization mode and set btc */
375 ti_hecc_reset(ndev);
376
377 priv->tx_head = priv->tx_tail = HECC_TX_MASK;
378 priv->rx_next = HECC_RX_FIRST_MBOX;
379
380 /* Enable local and global acceptance mask registers */
381 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
382
383 /* Prepare configured mailboxes to receive messages */
384 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
385 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
386 mbx_mask = BIT(mbxno);
387 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
388 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
389 hecc_write_lam(priv, mbxno, HECC_SET_REG);
390 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
391 hecc_set_bit(priv, HECC_CANME, mbx_mask);
392 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
393 }
394
395 /* Prevent message over-write & Enable interrupts */
396 hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
397 if (priv->use_hecc1int) {
398 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
399 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
400 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
401 } else {
402 hecc_write(priv, HECC_CANMIL, 0);
403 hecc_write(priv, HECC_CANGIM,
404 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
405 }
406 priv->can.state = CAN_STATE_ERROR_ACTIVE;
407}
408
409static void ti_hecc_stop(struct net_device *ndev)
410{
411 struct ti_hecc_priv *priv = netdev_priv(ndev);
412
413 /* Disable interrupts and disable mailboxes */
414 hecc_write(priv, HECC_CANGIM, 0);
415 hecc_write(priv, HECC_CANMIM, 0);
416 hecc_write(priv, HECC_CANME, 0);
417 priv->can.state = CAN_STATE_STOPPED;
418}
419
420static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
421{
422 int ret = 0;
423
424 switch (mode) {
425 case CAN_MODE_START:
426 ti_hecc_start(ndev);
427 netif_wake_queue(ndev);
428 break;
429 default:
430 ret = -EOPNOTSUPP;
431 break;
432 }
433
434 return ret;
435}
436
437static int ti_hecc_get_berr_counter(const struct net_device *ndev,
438 struct can_berr_counter *bec)
439{
440 struct ti_hecc_priv *priv = netdev_priv(ndev);
441
442 bec->txerr = hecc_read(priv, HECC_CANTEC);
443 bec->rxerr = hecc_read(priv, HECC_CANREC);
444
445 return 0;
446}
447
448/*
449 * ti_hecc_xmit: HECC Transmit
450 *
451 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
452 * priority of the mailbox for tranmission is dependent upon priority setting
453 * field in mailbox registers. The mailbox with highest value in priority field
454 * is transmitted first. Only when two mailboxes have the same value in
455 * priority field the highest numbered mailbox is transmitted first.
456 *
457 * To utilize the HECC priority feature as described above we start with the
458 * highest numbered mailbox with highest priority level and move on to the next
459 * mailbox with the same priority level and so on. Once we loop through all the
460 * transmit mailboxes we choose the next priority level (lower) and so on
461 * until we reach the lowest priority level on the lowest numbered mailbox
462 * when we stop transmission until all mailboxes are transmitted and then
463 * restart at highest numbered mailbox with highest priority.
464 *
465 * Two counters (head and tail) are used to track the next mailbox to transmit
466 * and to track the echo buffer for already transmitted mailbox. The queue
467 * is stopped when all the mailboxes are busy or when there is a priority
468 * value roll-over happens.
469 */
470static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
471{
472 struct ti_hecc_priv *priv = netdev_priv(ndev);
473 struct can_frame *cf = (struct can_frame *)skb->data;
474 u32 mbxno, mbx_mask, data;
475 unsigned long flags;
476
477 if (can_dropped_invalid_skb(ndev, skb))
478 return NETDEV_TX_OK;
479
480 mbxno = get_tx_head_mb(priv);
481 mbx_mask = BIT(mbxno);
482 spin_lock_irqsave(&priv->mbx_lock, flags);
483 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
484 spin_unlock_irqrestore(&priv->mbx_lock, flags);
485 netif_stop_queue(ndev);
486 netdev_err(priv->ndev,
487 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
488 priv->tx_head, priv->tx_tail);
489 return NETDEV_TX_BUSY;
490 }
491 spin_unlock_irqrestore(&priv->mbx_lock, flags);
492
493 /* Prepare mailbox for transmission */
494 data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
495 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
496 data |= HECC_CANMCF_RTR;
497 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
498
499 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
500 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
501 else /* Standard frame format */
502 data = (cf->can_id & CAN_SFF_MASK) << 18;
503 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
504 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
505 be32_to_cpu(*(__be32 *)(cf->data)));
506 if (cf->can_dlc > 4)
507 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
508 be32_to_cpu(*(__be32 *)(cf->data + 4)));
509 else
510 *(u32 *)(cf->data + 4) = 0;
511 can_put_echo_skb(skb, ndev, mbxno);
512
513 spin_lock_irqsave(&priv->mbx_lock, flags);
514 --priv->tx_head;
515 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
516 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
517 netif_stop_queue(ndev);
518 }
519 hecc_set_bit(priv, HECC_CANME, mbx_mask);
520 spin_unlock_irqrestore(&priv->mbx_lock, flags);
521
522 hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
523 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
524 hecc_write(priv, HECC_CANTRS, mbx_mask);
525
526 return NETDEV_TX_OK;
527}
528
529static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
530{
531 struct net_device_stats *stats = &priv->ndev->stats;
532 struct can_frame *cf;
533 struct sk_buff *skb;
534 u32 data, mbx_mask;
535 unsigned long flags;
536
537 skb = alloc_can_skb(priv->ndev, &cf);
538 if (!skb) {
539 if (printk_ratelimit())
540 netdev_err(priv->ndev,
541 "ti_hecc_rx_pkt: alloc_can_skb() failed\n");
542 return -ENOMEM;
543 }
544
545 mbx_mask = BIT(mbxno);
546 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
547 if (data & HECC_CANMID_IDE)
548 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
549 else
550 cf->can_id = (data >> 18) & CAN_SFF_MASK;
551 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
552 if (data & HECC_CANMCF_RTR)
553 cf->can_id |= CAN_RTR_FLAG;
554 cf->can_dlc = get_can_dlc(data & 0xF);
555 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
556 *(__be32 *)(cf->data) = cpu_to_be32(data);
557 if (cf->can_dlc > 4) {
558 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
559 *(__be32 *)(cf->data + 4) = cpu_to_be32(data);
560 }
561 spin_lock_irqsave(&priv->mbx_lock, flags);
562 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
563 hecc_write(priv, HECC_CANRMP, mbx_mask);
564 /* enable mailbox only if it is part of rx buffer mailboxes */
565 if (priv->rx_next < HECC_RX_BUFFER_MBOX)
566 hecc_set_bit(priv, HECC_CANME, mbx_mask);
567 spin_unlock_irqrestore(&priv->mbx_lock, flags);
568
569 stats->rx_bytes += cf->can_dlc;
570 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
571 netif_receive_skb(skb);
572 stats->rx_packets++;
573
574 return 0;
575}
576
577/*
578 * ti_hecc_rx_poll - HECC receive pkts
579 *
580 * The receive mailboxes start from highest numbered mailbox till last xmit
581 * mailbox. On CAN frame reception the hardware places the data into highest
582 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
583 * have same filtering (ALL CAN frames) packets will arrive in the highest
584 * available RX mailbox and we need to ensure in-order packet reception.
585 *
586 * To ensure the packets are received in the right order we logically divide
587 * the RX mailboxes into main and buffer mailboxes. Packets are received as per
588 * mailbox priotity (higher to lower) in the main bank and once it is full we
589 * disable further reception into main mailboxes. While the main mailboxes are
590 * processed in NAPI, further packets are received in buffer mailboxes.
591 *
592 * We maintain a RX next mailbox counter to process packets and once all main
593 * mailboxe packets are passed to the upper stack we enable all of them but
594 * continue to process packets received in buffer mailboxes. With each packet
595 * received from buffer mailbox we enable it immediately so as to handle the
596 * overflow from higher mailboxes.
597 */
598static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
599{
600 struct net_device *ndev = napi->dev;
601 struct ti_hecc_priv *priv = netdev_priv(ndev);
602 u32 num_pkts = 0;
603 u32 mbx_mask;
604 unsigned long pending_pkts, flags;
605
606 if (!netif_running(ndev))
607 return 0;
608
609 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
610 num_pkts < quota) {
611 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
612 if (mbx_mask & pending_pkts) {
613 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
614 return num_pkts;
615 ++num_pkts;
616 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
617 break; /* pkt not received yet */
618 }
619 --priv->rx_next;
620 if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
621 /* enable high bank mailboxes */
622 spin_lock_irqsave(&priv->mbx_lock, flags);
623 mbx_mask = hecc_read(priv, HECC_CANME);
624 mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
625 hecc_write(priv, HECC_CANME, mbx_mask);
626 spin_unlock_irqrestore(&priv->mbx_lock, flags);
627 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
628 priv->rx_next = HECC_RX_FIRST_MBOX;
629 break;
630 }
631 }
632
633 /* Enable packet interrupt if all pkts are handled */
634 if (hecc_read(priv, HECC_CANRMP) == 0) {
635 napi_complete(napi);
636 /* Re-enable RX mailbox interrupts */
637 mbx_mask = hecc_read(priv, HECC_CANMIM);
638 mbx_mask |= HECC_TX_MBOX_MASK;
639 hecc_write(priv, HECC_CANMIM, mbx_mask);
640 } else {
641 /* repoll is done only if whole budget is used */
642 num_pkts = quota;
643 }
644
645 return num_pkts;
646}
647
648static int ti_hecc_error(struct net_device *ndev, int int_status,
649 int err_status)
650{
651 struct ti_hecc_priv *priv = netdev_priv(ndev);
652 struct net_device_stats *stats = &ndev->stats;
653 struct can_frame *cf;
654 struct sk_buff *skb;
655
656 /* propagate the error condition to the can stack */
657 skb = alloc_can_err_skb(ndev, &cf);
658 if (!skb) {
659 if (printk_ratelimit())
660 netdev_err(priv->ndev,
661 "ti_hecc_error: alloc_can_err_skb() failed\n");
662 return -ENOMEM;
663 }
664
665 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
666 if ((int_status & HECC_CANGIF_BOIF) == 0) {
667 priv->can.state = CAN_STATE_ERROR_WARNING;
668 ++priv->can.can_stats.error_warning;
669 cf->can_id |= CAN_ERR_CRTL;
670 if (hecc_read(priv, HECC_CANTEC) > 96)
671 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
672 if (hecc_read(priv, HECC_CANREC) > 96)
673 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
674 }
675 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
676 netdev_dbg(priv->ndev, "Error Warning interrupt\n");
677 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
678 }
679
680 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
681 if ((int_status & HECC_CANGIF_BOIF) == 0) {
682 priv->can.state = CAN_STATE_ERROR_PASSIVE;
683 ++priv->can.can_stats.error_passive;
684 cf->can_id |= CAN_ERR_CRTL;
685 if (hecc_read(priv, HECC_CANTEC) > 127)
686 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
687 if (hecc_read(priv, HECC_CANREC) > 127)
688 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
689 }
690 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
691 netdev_dbg(priv->ndev, "Error passive interrupt\n");
692 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
693 }
694
695 /*
696 * Need to check busoff condition in error status register too to
697 * ensure warning interrupts don't hog the system
698 */
699 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
700 priv->can.state = CAN_STATE_BUS_OFF;
701 cf->can_id |= CAN_ERR_BUSOFF;
702 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
703 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
704 /* Disable all interrupts in bus-off to avoid int hog */
705 hecc_write(priv, HECC_CANGIM, 0);
706 ++priv->can.can_stats.bus_off;
707 can_bus_off(ndev);
708 }
709
710 if (err_status & HECC_BUS_ERROR) {
711 ++priv->can.can_stats.bus_error;
712 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
713 if (err_status & HECC_CANES_FE) {
714 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
715 cf->data[2] |= CAN_ERR_PROT_FORM;
716 }
717 if (err_status & HECC_CANES_BE) {
718 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
719 cf->data[2] |= CAN_ERR_PROT_BIT;
720 }
721 if (err_status & HECC_CANES_SE) {
722 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
723 cf->data[2] |= CAN_ERR_PROT_STUFF;
724 }
725 if (err_status & HECC_CANES_CRCE) {
726 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
727 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
728 }
729 if (err_status & HECC_CANES_ACKE) {
730 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
731 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
732 }
733 }
734
735 stats->rx_packets++;
736 stats->rx_bytes += cf->can_dlc;
737 netif_rx(skb);
738
739 return 0;
740}
741
742static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
743{
744 struct net_device *ndev = (struct net_device *)dev_id;
745 struct ti_hecc_priv *priv = netdev_priv(ndev);
746 struct net_device_stats *stats = &ndev->stats;
747 u32 mbxno, mbx_mask, int_status, err_status;
748 unsigned long ack, flags;
749
750 int_status = hecc_read(priv,
751 (priv->use_hecc1int) ? HECC_CANGIF1 : HECC_CANGIF0);
752
753 if (!int_status)
754 return IRQ_NONE;
755
756 err_status = hecc_read(priv, HECC_CANES);
757 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
758 HECC_CANES_EP | HECC_CANES_EW))
759 ti_hecc_error(ndev, int_status, err_status);
760
761 if (int_status & HECC_CANGIF_GMIF) {
762 while (priv->tx_tail - priv->tx_head > 0) {
763 mbxno = get_tx_tail_mb(priv);
764 mbx_mask = BIT(mbxno);
765 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
766 break;
767 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
768 hecc_write(priv, HECC_CANTA, mbx_mask);
769 spin_lock_irqsave(&priv->mbx_lock, flags);
770 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
771 spin_unlock_irqrestore(&priv->mbx_lock, flags);
772 stats->tx_bytes += hecc_read_mbx(priv, mbxno,
773 HECC_CANMCF) & 0xF;
774 stats->tx_packets++;
775 can_led_event(ndev, CAN_LED_EVENT_TX);
776 can_get_echo_skb(ndev, mbxno);
777 --priv->tx_tail;
778 }
779
780 /* restart queue if wrap-up or if queue stalled on last pkt */
781 if (((priv->tx_head == priv->tx_tail) &&
782 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
783 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
784 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
785 netif_wake_queue(ndev);
786
787 /* Disable RX mailbox interrupts and let NAPI reenable them */
788 if (hecc_read(priv, HECC_CANRMP)) {
789 ack = hecc_read(priv, HECC_CANMIM);
790 ack &= BIT(HECC_MAX_TX_MBOX) - 1;
791 hecc_write(priv, HECC_CANMIM, ack);
792 napi_schedule(&priv->napi);
793 }
794 }
795
796 /* clear all interrupt conditions - read back to avoid spurious ints */
797 if (priv->use_hecc1int) {
798 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
799 int_status = hecc_read(priv, HECC_CANGIF1);
800 } else {
801 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
802 int_status = hecc_read(priv, HECC_CANGIF0);
803 }
804
805 return IRQ_HANDLED;
806}
807
808static int ti_hecc_open(struct net_device *ndev)
809{
810 struct ti_hecc_priv *priv = netdev_priv(ndev);
811 int err;
812
813 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
814 ndev->name, ndev);
815 if (err) {
816 netdev_err(ndev, "error requesting interrupt\n");
817 return err;
818 }
819
820 ti_hecc_transceiver_switch(priv, 1);
821
822 /* Open common can device */
823 err = open_candev(ndev);
824 if (err) {
825 netdev_err(ndev, "open_candev() failed %d\n", err);
826 ti_hecc_transceiver_switch(priv, 0);
827 free_irq(ndev->irq, ndev);
828 return err;
829 }
830
831 can_led_event(ndev, CAN_LED_EVENT_OPEN);
832
833 ti_hecc_start(ndev);
834 napi_enable(&priv->napi);
835 netif_start_queue(ndev);
836
837 return 0;
838}
839
840static int ti_hecc_close(struct net_device *ndev)
841{
842 struct ti_hecc_priv *priv = netdev_priv(ndev);
843
844 netif_stop_queue(ndev);
845 napi_disable(&priv->napi);
846 ti_hecc_stop(ndev);
847 free_irq(ndev->irq, ndev);
848 close_candev(ndev);
849 ti_hecc_transceiver_switch(priv, 0);
850
851 can_led_event(ndev, CAN_LED_EVENT_STOP);
852
853 return 0;
854}
855
856static const struct net_device_ops ti_hecc_netdev_ops = {
857 .ndo_open = ti_hecc_open,
858 .ndo_stop = ti_hecc_close,
859 .ndo_start_xmit = ti_hecc_xmit,
860 .ndo_change_mtu = can_change_mtu,
861};
862
863static const struct of_device_id ti_hecc_dt_ids[] = {
864 {
865 .compatible = "ti,am3517-hecc",
866 },
867 { }
868};
869MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids);
870
871static int ti_hecc_probe(struct platform_device *pdev)
872{
873 struct net_device *ndev = (struct net_device *)0;
874 struct ti_hecc_priv *priv;
875 struct device_node *np = pdev->dev.of_node;
876 struct resource *res, *irq;
877 struct regulator *reg_xceiver;
878 int err = -ENODEV;
879
880 if (!IS_ENABLED(CONFIG_OF) || !np)
881 return -EINVAL;
882
883 reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
884 if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
885 return -EPROBE_DEFER;
886 else if (IS_ERR(reg_xceiver))
887 reg_xceiver = NULL;
888
889 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
890 if (!ndev) {
891 dev_err(&pdev->dev, "alloc_candev failed\n");
892 return -ENOMEM;
893 }
894 priv = netdev_priv(ndev);
895
896 /* handle hecc memory */
897 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hecc");
898 if (!res) {
899 dev_err(&pdev->dev, "can't get IORESOURCE_MEM hecc\n");
900 return -EINVAL;
901 }
902
903 priv->base = devm_ioremap_resource(&pdev->dev, res);
904 if (IS_ERR(priv->base)) {
905 dev_err(&pdev->dev, "hecc ioremap failed\n");
906 return PTR_ERR(priv->base);
907 }
908
909 /* handle hecc-ram memory */
910 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hecc-ram");
911 if (!res) {
912 dev_err(&pdev->dev, "can't get IORESOURCE_MEM hecc-ram\n");
913 return -EINVAL;
914 }
915
916 priv->hecc_ram = devm_ioremap_resource(&pdev->dev, res);
917 if (IS_ERR(priv->hecc_ram)) {
918 dev_err(&pdev->dev, "hecc-ram ioremap failed\n");
919 return PTR_ERR(priv->hecc_ram);
920 }
921
922 /* handle mbx memory */
923 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbx");
924 if (!res) {
925 dev_err(&pdev->dev, "can't get IORESOURCE_MEM mbx\n");
926 return -EINVAL;
927 }
928
929 priv->mbx = devm_ioremap_resource(&pdev->dev, res);
930 if (IS_ERR(priv->mbx)) {
931 dev_err(&pdev->dev, "mbx ioremap failed\n");
932 return PTR_ERR(priv->mbx);
933 }
934
935 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
936 if (!irq) {
937 dev_err(&pdev->dev, "No irq resource\n");
938 goto probe_exit;
939 }
940
941 priv->ndev = ndev;
942 priv->reg_xceiver = reg_xceiver;
943 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int");
944
945 priv->can.bittiming_const = &ti_hecc_bittiming_const;
946 priv->can.do_set_mode = ti_hecc_do_set_mode;
947 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
948 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
949
950 spin_lock_init(&priv->mbx_lock);
951 ndev->irq = irq->start;
952 ndev->flags |= IFF_ECHO;
953 platform_set_drvdata(pdev, ndev);
954 SET_NETDEV_DEV(ndev, &pdev->dev);
955 ndev->netdev_ops = &ti_hecc_netdev_ops;
956
957 priv->clk = clk_get(&pdev->dev, "hecc_ck");
958 if (IS_ERR(priv->clk)) {
959 dev_err(&pdev->dev, "No clock available\n");
960 err = PTR_ERR(priv->clk);
961 priv->clk = NULL;
962 goto probe_exit_candev;
963 }
964 priv->can.clock.freq = clk_get_rate(priv->clk);
965 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
966 HECC_DEF_NAPI_WEIGHT);
967
968 err = clk_prepare_enable(priv->clk);
969 if (err) {
970 dev_err(&pdev->dev, "clk_prepare_enable() failed\n");
971 goto probe_exit_clk;
972 }
973
974 err = register_candev(ndev);
975 if (err) {
976 dev_err(&pdev->dev, "register_candev() failed\n");
977 goto probe_exit_clk;
978 }
979
980 devm_can_led_init(ndev);
981
982 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
983 priv->base, (u32) ndev->irq);
984
985 return 0;
986
987probe_exit_clk:
988 clk_put(priv->clk);
989probe_exit_candev:
990 free_candev(ndev);
991probe_exit:
992 return err;
993}
994
995static int ti_hecc_remove(struct platform_device *pdev)
996{
997 struct net_device *ndev = platform_get_drvdata(pdev);
998 struct ti_hecc_priv *priv = netdev_priv(ndev);
999
1000 unregister_candev(ndev);
1001 clk_disable_unprepare(priv->clk);
1002 clk_put(priv->clk);
1003 free_candev(ndev);
1004
1005 return 0;
1006}
1007
1008#ifdef CONFIG_PM
1009static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
1010{
1011 struct net_device *dev = platform_get_drvdata(pdev);
1012 struct ti_hecc_priv *priv = netdev_priv(dev);
1013
1014 if (netif_running(dev)) {
1015 netif_stop_queue(dev);
1016 netif_device_detach(dev);
1017 }
1018
1019 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1020 priv->can.state = CAN_STATE_SLEEPING;
1021
1022 clk_disable_unprepare(priv->clk);
1023
1024 return 0;
1025}
1026
1027static int ti_hecc_resume(struct platform_device *pdev)
1028{
1029 struct net_device *dev = platform_get_drvdata(pdev);
1030 struct ti_hecc_priv *priv = netdev_priv(dev);
1031 int err;
1032
1033 err = clk_prepare_enable(priv->clk);
1034 if (err)
1035 return err;
1036
1037 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1038 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1039
1040 if (netif_running(dev)) {
1041 netif_device_attach(dev);
1042 netif_start_queue(dev);
1043 }
1044
1045 return 0;
1046}
1047#else
1048#define ti_hecc_suspend NULL
1049#define ti_hecc_resume NULL
1050#endif
1051
1052/* TI HECC netdevice driver: platform driver structure */
1053static struct platform_driver ti_hecc_driver = {
1054 .driver = {
1055 .name = DRV_NAME,
1056 .of_match_table = ti_hecc_dt_ids,
1057 },
1058 .probe = ti_hecc_probe,
1059 .remove = ti_hecc_remove,
1060 .suspend = ti_hecc_suspend,
1061 .resume = ti_hecc_resume,
1062};
1063
1064module_platform_driver(ti_hecc_driver);
1065
1066MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1067MODULE_LICENSE("GPL v2");
1068MODULE_DESCRIPTION(DRV_DESC);
1069MODULE_ALIAS("platform:" DRV_NAME);
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 * Copyright (C) 2019 Jeroen Hofstee <jhofstee@victronenergy.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation version 2.
13 *
14 * This program is distributed as is WITHOUT ANY WARRANTY of any
15 * kind, whether express or implied; without even the implied warranty
16 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 */
20
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/types.h>
24#include <linux/interrupt.h>
25#include <linux/errno.h>
26#include <linux/netdevice.h>
27#include <linux/skbuff.h>
28#include <linux/platform_device.h>
29#include <linux/clk.h>
30#include <linux/io.h>
31#include <linux/of.h>
32#include <linux/of_device.h>
33#include <linux/regulator/consumer.h>
34
35#include <linux/can/dev.h>
36#include <linux/can/error.h>
37#include <linux/can/led.h>
38#include <linux/can/rx-offload.h>
39
40#define DRV_NAME "ti_hecc"
41#define HECC_MODULE_VERSION "0.7"
42MODULE_VERSION(HECC_MODULE_VERSION);
43#define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
44
45/* TX / RX Mailbox Configuration */
46#define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
47#define MAX_TX_PRIO 0x3F /* hardware value - do not change */
48
49/* Important Note: TX mailbox configuration
50 * TX mailboxes should be restricted to the number of SKB buffers to avoid
51 * maintaining SKB buffers separately. TX mailboxes should be a power of 2
52 * for the mailbox logic to work. Top mailbox numbers are reserved for RX
53 * and lower mailboxes for TX.
54 *
55 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
56 * 4 (default) 2
57 * 8 3
58 * 16 4
59 */
60#define HECC_MB_TX_SHIFT 2 /* as per table above */
61#define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
62
63#define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
64#define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
65#define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
66#define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
67
68/* RX mailbox configuration
69 *
70 * The remaining mailboxes are used for reception and are delivered
71 * based on their timestamp, to avoid a hardware race when CANME is
72 * changed while CAN-bus traffic is being received.
73 */
74#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
75#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
76#define HECC_RX_LAST_MBOX (HECC_MAX_TX_MBOX)
77
78/* TI HECC module registers */
79#define HECC_CANME 0x0 /* Mailbox enable */
80#define HECC_CANMD 0x4 /* Mailbox direction */
81#define HECC_CANTRS 0x8 /* Transmit request set */
82#define HECC_CANTRR 0xC /* Transmit request */
83#define HECC_CANTA 0x10 /* Transmission acknowledge */
84#define HECC_CANAA 0x14 /* Abort acknowledge */
85#define HECC_CANRMP 0x18 /* Receive message pending */
86#define HECC_CANRML 0x1C /* Receive message lost */
87#define HECC_CANRFP 0x20 /* Remote frame pending */
88#define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
89#define HECC_CANMC 0x28 /* Master control */
90#define HECC_CANBTC 0x2C /* Bit timing configuration */
91#define HECC_CANES 0x30 /* Error and status */
92#define HECC_CANTEC 0x34 /* Transmit error counter */
93#define HECC_CANREC 0x38 /* Receive error counter */
94#define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
95#define HECC_CANGIM 0x40 /* Global interrupt mask */
96#define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
97#define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
98#define HECC_CANMIL 0x4C /* Mailbox interrupt level */
99#define HECC_CANOPC 0x50 /* Overwrite protection control */
100#define HECC_CANTIOC 0x54 /* Transmit I/O control */
101#define HECC_CANRIOC 0x58 /* Receive I/O control */
102#define HECC_CANLNT 0x5C /* HECC only: Local network time */
103#define HECC_CANTOC 0x60 /* HECC only: Time-out control */
104#define HECC_CANTOS 0x64 /* HECC only: Time-out status */
105#define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
106#define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
107
108/* TI HECC RAM registers */
109#define HECC_CANMOTS 0x80 /* Message object time stamp */
110
111/* Mailbox registers */
112#define HECC_CANMID 0x0
113#define HECC_CANMCF 0x4
114#define HECC_CANMDL 0x8
115#define HECC_CANMDH 0xC
116
117#define HECC_SET_REG 0xFFFFFFFF
118#define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
119#define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
120
121#define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
122#define HECC_CANMC_CCR BIT(12) /* Change config request */
123#define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
124#define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
125#define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
126#define HECC_CANMC_SRES BIT(5) /* Software reset */
127
128#define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
129#define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
130
131#define HECC_CANMID_IDE BIT(31) /* Extended frame format */
132#define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
133#define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
134
135#define HECC_CANES_FE BIT(24) /* form error */
136#define HECC_CANES_BE BIT(23) /* bit error */
137#define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
138#define HECC_CANES_CRCE BIT(21) /* CRC error */
139#define HECC_CANES_SE BIT(20) /* stuff bit error */
140#define HECC_CANES_ACKE BIT(19) /* ack error */
141#define HECC_CANES_BO BIT(18) /* Bus off status */
142#define HECC_CANES_EP BIT(17) /* Error passive status */
143#define HECC_CANES_EW BIT(16) /* Error warning status */
144#define HECC_CANES_SMA BIT(5) /* suspend mode ack */
145#define HECC_CANES_CCE BIT(4) /* Change config enabled */
146#define HECC_CANES_PDA BIT(3) /* Power down mode ack */
147
148#define HECC_CANBTC_SAM BIT(7) /* sample points */
149
150#define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
151 HECC_CANES_CRCE | HECC_CANES_SE |\
152 HECC_CANES_ACKE)
153#define HECC_CANES_FLAGS (HECC_BUS_ERROR | HECC_CANES_BO |\
154 HECC_CANES_EP | HECC_CANES_EW)
155
156#define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
157
158#define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
159#define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
160#define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
161#define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
162#define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
163#define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
164#define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
165#define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
166#define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
167#define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
168#define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
169#define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
170#define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
171#define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
172#define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
173
174/* CAN Bittiming constants as per HECC specs */
175static const struct can_bittiming_const ti_hecc_bittiming_const = {
176 .name = DRV_NAME,
177 .tseg1_min = 1,
178 .tseg1_max = 16,
179 .tseg2_min = 1,
180 .tseg2_max = 8,
181 .sjw_max = 4,
182 .brp_min = 1,
183 .brp_max = 256,
184 .brp_inc = 1,
185};
186
187struct ti_hecc_priv {
188 struct can_priv can; /* MUST be first member/field */
189 struct can_rx_offload offload;
190 struct net_device *ndev;
191 struct clk *clk;
192 void __iomem *base;
193 void __iomem *hecc_ram;
194 void __iomem *mbx;
195 bool use_hecc1int;
196 spinlock_t mbx_lock; /* CANME register needs protection */
197 u32 tx_head;
198 u32 tx_tail;
199 struct regulator *reg_xceiver;
200};
201
202static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
203{
204 return priv->tx_head & HECC_TX_MB_MASK;
205}
206
207static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
208{
209 return priv->tx_tail & HECC_TX_MB_MASK;
210}
211
212static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
213{
214 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
215}
216
217static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
218{
219 __raw_writel(val, priv->hecc_ram + mbxno * 4);
220}
221
222static inline u32 hecc_read_stamp(struct ti_hecc_priv *priv, u32 mbxno)
223{
224 return __raw_readl(priv->hecc_ram + HECC_CANMOTS + mbxno * 4);
225}
226
227static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
228 u32 reg, u32 val)
229{
230 __raw_writel(val, priv->mbx + mbxno * 0x10 + reg);
231}
232
233static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
234{
235 return __raw_readl(priv->mbx + mbxno * 0x10 + reg);
236}
237
238static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
239{
240 __raw_writel(val, priv->base + reg);
241}
242
243static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
244{
245 return __raw_readl(priv->base + reg);
246}
247
248static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
249 u32 bit_mask)
250{
251 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
252}
253
254static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
255 u32 bit_mask)
256{
257 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
258}
259
260static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
261{
262 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
263}
264
265static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
266{
267 struct can_bittiming *bit_timing = &priv->can.bittiming;
268 u32 can_btc;
269
270 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
271 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
272 & 0xF) << 3;
273 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
274 if (bit_timing->brp > 4)
275 can_btc |= HECC_CANBTC_SAM;
276 else
277 netdev_warn(priv->ndev,
278 "WARN: Triple sampling not set due to h/w limitations");
279 }
280 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
281 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
282
283 /* ERM being set to 0 by default meaning resync at falling edge */
284
285 hecc_write(priv, HECC_CANBTC, can_btc);
286 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
287
288 return 0;
289}
290
291static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
292 int on)
293{
294 if (!priv->reg_xceiver)
295 return 0;
296
297 if (on)
298 return regulator_enable(priv->reg_xceiver);
299 else
300 return regulator_disable(priv->reg_xceiver);
301}
302
303static void ti_hecc_reset(struct net_device *ndev)
304{
305 u32 cnt;
306 struct ti_hecc_priv *priv = netdev_priv(ndev);
307
308 netdev_dbg(ndev, "resetting hecc ...\n");
309 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
310
311 /* Set change control request and wait till enabled */
312 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
313
314 /* INFO: It has been observed that at times CCE bit may not be
315 * set and hw seems to be ok even if this bit is not set so
316 * timing out with a timing of 1ms to respect the specs
317 */
318 cnt = HECC_CCE_WAIT_COUNT;
319 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
320 --cnt;
321 udelay(10);
322 }
323
324 /* Note: On HECC, BTC can be programmed only in initialization mode, so
325 * it is expected that the can bittiming parameters are set via ip
326 * utility before the device is opened
327 */
328 ti_hecc_set_btc(priv);
329
330 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
331 hecc_write(priv, HECC_CANMC, 0);
332
333 /* INFO: CAN net stack handles bus off and hence disabling auto-bus-on
334 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
335 */
336
337 /* INFO: It has been observed that at times CCE bit may not be
338 * set and hw seems to be ok even if this bit is not set so
339 */
340 cnt = HECC_CCE_WAIT_COUNT;
341 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
342 --cnt;
343 udelay(10);
344 }
345
346 /* Enable TX and RX I/O Control pins */
347 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
348 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
349
350 /* Clear registers for clean operation */
351 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
352 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
353 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
354 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
355 hecc_write(priv, HECC_CANME, 0);
356 hecc_write(priv, HECC_CANMD, 0);
357
358 /* SCC compat mode NOT supported (and not needed too) */
359 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
360}
361
362static void ti_hecc_start(struct net_device *ndev)
363{
364 struct ti_hecc_priv *priv = netdev_priv(ndev);
365 u32 cnt, mbxno, mbx_mask;
366
367 /* put HECC in initialization mode and set btc */
368 ti_hecc_reset(ndev);
369
370 priv->tx_head = HECC_TX_MASK;
371 priv->tx_tail = HECC_TX_MASK;
372
373 /* Enable local and global acceptance mask registers */
374 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
375
376 /* Prepare configured mailboxes to receive messages */
377 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
378 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
379 mbx_mask = BIT(mbxno);
380 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
381 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
382 hecc_write_lam(priv, mbxno, HECC_SET_REG);
383 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
384 hecc_set_bit(priv, HECC_CANME, mbx_mask);
385 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
386 }
387
388 /* Enable tx interrupts */
389 hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1);
390
391 /* Prevent message over-write to create a rx fifo, but not for
392 * the lowest priority mailbox, since that allows detecting
393 * overflows instead of the hardware silently dropping the
394 * messages.
395 */
396 mbx_mask = ~BIT(HECC_RX_LAST_MBOX);
397 hecc_write(priv, HECC_CANOPC, mbx_mask);
398
399 /* Enable interrupts */
400 if (priv->use_hecc1int) {
401 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
402 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
403 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
404 } else {
405 hecc_write(priv, HECC_CANMIL, 0);
406 hecc_write(priv, HECC_CANGIM,
407 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
408 }
409 priv->can.state = CAN_STATE_ERROR_ACTIVE;
410}
411
412static void ti_hecc_stop(struct net_device *ndev)
413{
414 struct ti_hecc_priv *priv = netdev_priv(ndev);
415
416 /* Disable the CPK; stop sending, erroring and acking */
417 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
418
419 /* Disable interrupts and disable mailboxes */
420 hecc_write(priv, HECC_CANGIM, 0);
421 hecc_write(priv, HECC_CANMIM, 0);
422 hecc_write(priv, HECC_CANME, 0);
423 priv->can.state = CAN_STATE_STOPPED;
424}
425
426static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
427{
428 int ret = 0;
429
430 switch (mode) {
431 case CAN_MODE_START:
432 ti_hecc_start(ndev);
433 netif_wake_queue(ndev);
434 break;
435 default:
436 ret = -EOPNOTSUPP;
437 break;
438 }
439
440 return ret;
441}
442
443static int ti_hecc_get_berr_counter(const struct net_device *ndev,
444 struct can_berr_counter *bec)
445{
446 struct ti_hecc_priv *priv = netdev_priv(ndev);
447
448 bec->txerr = hecc_read(priv, HECC_CANTEC);
449 bec->rxerr = hecc_read(priv, HECC_CANREC);
450
451 return 0;
452}
453
454/* ti_hecc_xmit: HECC Transmit
455 *
456 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
457 * priority of the mailbox for transmission is dependent upon priority setting
458 * field in mailbox registers. The mailbox with highest value in priority field
459 * is transmitted first. Only when two mailboxes have the same value in
460 * priority field the highest numbered mailbox is transmitted first.
461 *
462 * To utilize the HECC priority feature as described above we start with the
463 * highest numbered mailbox with highest priority level and move on to the next
464 * mailbox with the same priority level and so on. Once we loop through all the
465 * transmit mailboxes we choose the next priority level (lower) and so on
466 * until we reach the lowest priority level on the lowest numbered mailbox
467 * when we stop transmission until all mailboxes are transmitted and then
468 * restart at highest numbered mailbox with highest priority.
469 *
470 * Two counters (head and tail) are used to track the next mailbox to transmit
471 * and to track the echo buffer for already transmitted mailbox. The queue
472 * is stopped when all the mailboxes are busy or when there is a priority
473 * value roll-over happens.
474 */
475static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
476{
477 struct ti_hecc_priv *priv = netdev_priv(ndev);
478 struct can_frame *cf = (struct can_frame *)skb->data;
479 u32 mbxno, mbx_mask, data;
480 unsigned long flags;
481
482 if (can_dropped_invalid_skb(ndev, skb))
483 return NETDEV_TX_OK;
484
485 mbxno = get_tx_head_mb(priv);
486 mbx_mask = BIT(mbxno);
487 spin_lock_irqsave(&priv->mbx_lock, flags);
488 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
489 spin_unlock_irqrestore(&priv->mbx_lock, flags);
490 netif_stop_queue(ndev);
491 netdev_err(priv->ndev,
492 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
493 priv->tx_head, priv->tx_tail);
494 return NETDEV_TX_BUSY;
495 }
496 spin_unlock_irqrestore(&priv->mbx_lock, flags);
497
498 /* Prepare mailbox for transmission */
499 data = cf->len | (get_tx_head_prio(priv) << 8);
500 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
501 data |= HECC_CANMCF_RTR;
502 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
503
504 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
505 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
506 else /* Standard frame format */
507 data = (cf->can_id & CAN_SFF_MASK) << 18;
508 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
509 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
510 be32_to_cpu(*(__be32 *)(cf->data)));
511 if (cf->len > 4)
512 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
513 be32_to_cpu(*(__be32 *)(cf->data + 4)));
514 else
515 *(u32 *)(cf->data + 4) = 0;
516 can_put_echo_skb(skb, ndev, mbxno, 0);
517
518 spin_lock_irqsave(&priv->mbx_lock, flags);
519 --priv->tx_head;
520 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
521 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
522 netif_stop_queue(ndev);
523 }
524 hecc_set_bit(priv, HECC_CANME, mbx_mask);
525 spin_unlock_irqrestore(&priv->mbx_lock, flags);
526
527 hecc_write(priv, HECC_CANTRS, mbx_mask);
528
529 return NETDEV_TX_OK;
530}
531
532static inline
533struct ti_hecc_priv *rx_offload_to_priv(struct can_rx_offload *offload)
534{
535 return container_of(offload, struct ti_hecc_priv, offload);
536}
537
538static struct sk_buff *ti_hecc_mailbox_read(struct can_rx_offload *offload,
539 unsigned int mbxno, u32 *timestamp,
540 bool drop)
541{
542 struct ti_hecc_priv *priv = rx_offload_to_priv(offload);
543 struct sk_buff *skb;
544 struct can_frame *cf;
545 u32 data, mbx_mask;
546
547 mbx_mask = BIT(mbxno);
548
549 if (unlikely(drop)) {
550 skb = ERR_PTR(-ENOBUFS);
551 goto mark_as_read;
552 }
553
554 skb = alloc_can_skb(offload->dev, &cf);
555 if (unlikely(!skb)) {
556 skb = ERR_PTR(-ENOMEM);
557 goto mark_as_read;
558 }
559
560 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
561 if (data & HECC_CANMID_IDE)
562 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
563 else
564 cf->can_id = (data >> 18) & CAN_SFF_MASK;
565
566 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
567 if (data & HECC_CANMCF_RTR)
568 cf->can_id |= CAN_RTR_FLAG;
569 cf->len = can_cc_dlc2len(data & 0xF);
570
571 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
572 *(__be32 *)(cf->data) = cpu_to_be32(data);
573 if (cf->len > 4) {
574 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
575 *(__be32 *)(cf->data + 4) = cpu_to_be32(data);
576 }
577
578 *timestamp = hecc_read_stamp(priv, mbxno);
579
580 /* Check for FIFO overrun.
581 *
582 * All but the last RX mailbox have activated overwrite
583 * protection. So skip check for overrun, if we're not
584 * handling the last RX mailbox.
585 *
586 * As the overwrite protection for the last RX mailbox is
587 * disabled, the CAN core might update while we're reading
588 * it. This means the skb might be inconsistent.
589 *
590 * Return an error to let rx-offload discard this CAN frame.
591 */
592 if (unlikely(mbxno == HECC_RX_LAST_MBOX &&
593 hecc_read(priv, HECC_CANRML) & mbx_mask))
594 skb = ERR_PTR(-ENOBUFS);
595
596 mark_as_read:
597 hecc_write(priv, HECC_CANRMP, mbx_mask);
598
599 return skb;
600}
601
602static int ti_hecc_error(struct net_device *ndev, int int_status,
603 int err_status)
604{
605 struct ti_hecc_priv *priv = netdev_priv(ndev);
606 struct can_frame *cf;
607 struct sk_buff *skb;
608 u32 timestamp;
609 int err;
610
611 if (err_status & HECC_BUS_ERROR) {
612 /* propagate the error condition to the can stack */
613 skb = alloc_can_err_skb(ndev, &cf);
614 if (!skb) {
615 if (net_ratelimit())
616 netdev_err(priv->ndev,
617 "%s: alloc_can_err_skb() failed\n",
618 __func__);
619 return -ENOMEM;
620 }
621
622 ++priv->can.can_stats.bus_error;
623 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
624 if (err_status & HECC_CANES_FE)
625 cf->data[2] |= CAN_ERR_PROT_FORM;
626 if (err_status & HECC_CANES_BE)
627 cf->data[2] |= CAN_ERR_PROT_BIT;
628 if (err_status & HECC_CANES_SE)
629 cf->data[2] |= CAN_ERR_PROT_STUFF;
630 if (err_status & HECC_CANES_CRCE)
631 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
632 if (err_status & HECC_CANES_ACKE)
633 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
634
635 timestamp = hecc_read(priv, HECC_CANLNT);
636 err = can_rx_offload_queue_sorted(&priv->offload, skb,
637 timestamp);
638 if (err)
639 ndev->stats.rx_fifo_errors++;
640 }
641
642 hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS);
643
644 return 0;
645}
646
647static void ti_hecc_change_state(struct net_device *ndev,
648 enum can_state rx_state,
649 enum can_state tx_state)
650{
651 struct ti_hecc_priv *priv = netdev_priv(ndev);
652 struct can_frame *cf;
653 struct sk_buff *skb;
654 u32 timestamp;
655 int err;
656
657 skb = alloc_can_err_skb(priv->ndev, &cf);
658 if (unlikely(!skb)) {
659 priv->can.state = max(tx_state, rx_state);
660 return;
661 }
662
663 can_change_state(priv->ndev, cf, tx_state, rx_state);
664
665 if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) {
666 cf->data[6] = hecc_read(priv, HECC_CANTEC);
667 cf->data[7] = hecc_read(priv, HECC_CANREC);
668 }
669
670 timestamp = hecc_read(priv, HECC_CANLNT);
671 err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
672 if (err)
673 ndev->stats.rx_fifo_errors++;
674}
675
676static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
677{
678 struct net_device *ndev = (struct net_device *)dev_id;
679 struct ti_hecc_priv *priv = netdev_priv(ndev);
680 struct net_device_stats *stats = &ndev->stats;
681 u32 mbxno, mbx_mask, int_status, err_status, stamp;
682 unsigned long flags, rx_pending;
683 u32 handled = 0;
684
685 int_status = hecc_read(priv,
686 priv->use_hecc1int ?
687 HECC_CANGIF1 : HECC_CANGIF0);
688
689 if (!int_status)
690 return IRQ_NONE;
691
692 err_status = hecc_read(priv, HECC_CANES);
693 if (unlikely(err_status & HECC_CANES_FLAGS))
694 ti_hecc_error(ndev, int_status, err_status);
695
696 if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) {
697 enum can_state rx_state, tx_state;
698 u32 rec = hecc_read(priv, HECC_CANREC);
699 u32 tec = hecc_read(priv, HECC_CANTEC);
700
701 if (int_status & HECC_CANGIF_WLIF) {
702 handled |= HECC_CANGIF_WLIF;
703 rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0;
704 tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0;
705 netdev_dbg(priv->ndev, "Error Warning interrupt\n");
706 ti_hecc_change_state(ndev, rx_state, tx_state);
707 }
708
709 if (int_status & HECC_CANGIF_EPIF) {
710 handled |= HECC_CANGIF_EPIF;
711 rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0;
712 tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0;
713 netdev_dbg(priv->ndev, "Error passive interrupt\n");
714 ti_hecc_change_state(ndev, rx_state, tx_state);
715 }
716
717 if (int_status & HECC_CANGIF_BOIF) {
718 handled |= HECC_CANGIF_BOIF;
719 rx_state = CAN_STATE_BUS_OFF;
720 tx_state = CAN_STATE_BUS_OFF;
721 netdev_dbg(priv->ndev, "Bus off interrupt\n");
722
723 /* Disable all interrupts */
724 hecc_write(priv, HECC_CANGIM, 0);
725 can_bus_off(ndev);
726 ti_hecc_change_state(ndev, rx_state, tx_state);
727 }
728 } else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) {
729 enum can_state new_state, tx_state, rx_state;
730 u32 rec = hecc_read(priv, HECC_CANREC);
731 u32 tec = hecc_read(priv, HECC_CANTEC);
732
733 if (rec >= 128 || tec >= 128)
734 new_state = CAN_STATE_ERROR_PASSIVE;
735 else if (rec >= 96 || tec >= 96)
736 new_state = CAN_STATE_ERROR_WARNING;
737 else
738 new_state = CAN_STATE_ERROR_ACTIVE;
739
740 if (new_state < priv->can.state) {
741 rx_state = rec >= tec ? new_state : 0;
742 tx_state = rec <= tec ? new_state : 0;
743 ti_hecc_change_state(ndev, rx_state, tx_state);
744 }
745 }
746
747 if (int_status & HECC_CANGIF_GMIF) {
748 while (priv->tx_tail - priv->tx_head > 0) {
749 mbxno = get_tx_tail_mb(priv);
750 mbx_mask = BIT(mbxno);
751 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
752 break;
753 hecc_write(priv, HECC_CANTA, mbx_mask);
754 spin_lock_irqsave(&priv->mbx_lock, flags);
755 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
756 spin_unlock_irqrestore(&priv->mbx_lock, flags);
757 stamp = hecc_read_stamp(priv, mbxno);
758 stats->tx_bytes +=
759 can_rx_offload_get_echo_skb(&priv->offload,
760 mbxno, stamp, NULL);
761 stats->tx_packets++;
762 can_led_event(ndev, CAN_LED_EVENT_TX);
763 --priv->tx_tail;
764 }
765
766 /* restart queue if wrap-up or if queue stalled on last pkt */
767 if ((priv->tx_head == priv->tx_tail &&
768 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
769 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
770 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
771 netif_wake_queue(ndev);
772
773 /* offload RX mailboxes and let NAPI deliver them */
774 while ((rx_pending = hecc_read(priv, HECC_CANRMP))) {
775 can_rx_offload_irq_offload_timestamp(&priv->offload,
776 rx_pending);
777 }
778 }
779
780 /* clear all interrupt conditions - read back to avoid spurious ints */
781 if (priv->use_hecc1int) {
782 hecc_write(priv, HECC_CANGIF1, handled);
783 int_status = hecc_read(priv, HECC_CANGIF1);
784 } else {
785 hecc_write(priv, HECC_CANGIF0, handled);
786 int_status = hecc_read(priv, HECC_CANGIF0);
787 }
788
789 return IRQ_HANDLED;
790}
791
792static int ti_hecc_open(struct net_device *ndev)
793{
794 struct ti_hecc_priv *priv = netdev_priv(ndev);
795 int err;
796
797 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
798 ndev->name, ndev);
799 if (err) {
800 netdev_err(ndev, "error requesting interrupt\n");
801 return err;
802 }
803
804 ti_hecc_transceiver_switch(priv, 1);
805
806 /* Open common can device */
807 err = open_candev(ndev);
808 if (err) {
809 netdev_err(ndev, "open_candev() failed %d\n", err);
810 ti_hecc_transceiver_switch(priv, 0);
811 free_irq(ndev->irq, ndev);
812 return err;
813 }
814
815 can_led_event(ndev, CAN_LED_EVENT_OPEN);
816
817 ti_hecc_start(ndev);
818 can_rx_offload_enable(&priv->offload);
819 netif_start_queue(ndev);
820
821 return 0;
822}
823
824static int ti_hecc_close(struct net_device *ndev)
825{
826 struct ti_hecc_priv *priv = netdev_priv(ndev);
827
828 netif_stop_queue(ndev);
829 can_rx_offload_disable(&priv->offload);
830 ti_hecc_stop(ndev);
831 free_irq(ndev->irq, ndev);
832 close_candev(ndev);
833 ti_hecc_transceiver_switch(priv, 0);
834
835 can_led_event(ndev, CAN_LED_EVENT_STOP);
836
837 return 0;
838}
839
840static const struct net_device_ops ti_hecc_netdev_ops = {
841 .ndo_open = ti_hecc_open,
842 .ndo_stop = ti_hecc_close,
843 .ndo_start_xmit = ti_hecc_xmit,
844 .ndo_change_mtu = can_change_mtu,
845};
846
847static const struct of_device_id ti_hecc_dt_ids[] = {
848 {
849 .compatible = "ti,am3517-hecc",
850 },
851 { }
852};
853MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids);
854
855static int ti_hecc_probe(struct platform_device *pdev)
856{
857 struct net_device *ndev = (struct net_device *)0;
858 struct ti_hecc_priv *priv;
859 struct device_node *np = pdev->dev.of_node;
860 struct resource *irq;
861 struct regulator *reg_xceiver;
862 int err = -ENODEV;
863
864 if (!IS_ENABLED(CONFIG_OF) || !np)
865 return -EINVAL;
866
867 reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
868 if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
869 return -EPROBE_DEFER;
870 else if (IS_ERR(reg_xceiver))
871 reg_xceiver = NULL;
872
873 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
874 if (!ndev) {
875 dev_err(&pdev->dev, "alloc_candev failed\n");
876 return -ENOMEM;
877 }
878 priv = netdev_priv(ndev);
879
880 /* handle hecc memory */
881 priv->base = devm_platform_ioremap_resource_byname(pdev, "hecc");
882 if (IS_ERR(priv->base)) {
883 dev_err(&pdev->dev, "hecc ioremap failed\n");
884 err = PTR_ERR(priv->base);
885 goto probe_exit_candev;
886 }
887
888 /* handle hecc-ram memory */
889 priv->hecc_ram = devm_platform_ioremap_resource_byname(pdev,
890 "hecc-ram");
891 if (IS_ERR(priv->hecc_ram)) {
892 dev_err(&pdev->dev, "hecc-ram ioremap failed\n");
893 err = PTR_ERR(priv->hecc_ram);
894 goto probe_exit_candev;
895 }
896
897 /* handle mbx memory */
898 priv->mbx = devm_platform_ioremap_resource_byname(pdev, "mbx");
899 if (IS_ERR(priv->mbx)) {
900 dev_err(&pdev->dev, "mbx ioremap failed\n");
901 err = PTR_ERR(priv->mbx);
902 goto probe_exit_candev;
903 }
904
905 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
906 if (!irq) {
907 dev_err(&pdev->dev, "No irq resource\n");
908 goto probe_exit_candev;
909 }
910
911 priv->ndev = ndev;
912 priv->reg_xceiver = reg_xceiver;
913 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int");
914
915 priv->can.bittiming_const = &ti_hecc_bittiming_const;
916 priv->can.do_set_mode = ti_hecc_do_set_mode;
917 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
918 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
919
920 spin_lock_init(&priv->mbx_lock);
921 ndev->irq = irq->start;
922 ndev->flags |= IFF_ECHO;
923 platform_set_drvdata(pdev, ndev);
924 SET_NETDEV_DEV(ndev, &pdev->dev);
925 ndev->netdev_ops = &ti_hecc_netdev_ops;
926
927 priv->clk = clk_get(&pdev->dev, "hecc_ck");
928 if (IS_ERR(priv->clk)) {
929 dev_err(&pdev->dev, "No clock available\n");
930 err = PTR_ERR(priv->clk);
931 priv->clk = NULL;
932 goto probe_exit_candev;
933 }
934 priv->can.clock.freq = clk_get_rate(priv->clk);
935
936 err = clk_prepare_enable(priv->clk);
937 if (err) {
938 dev_err(&pdev->dev, "clk_prepare_enable() failed\n");
939 goto probe_exit_release_clk;
940 }
941
942 priv->offload.mailbox_read = ti_hecc_mailbox_read;
943 priv->offload.mb_first = HECC_RX_FIRST_MBOX;
944 priv->offload.mb_last = HECC_RX_LAST_MBOX;
945 err = can_rx_offload_add_timestamp(ndev, &priv->offload);
946 if (err) {
947 dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n");
948 goto probe_exit_disable_clk;
949 }
950
951 err = register_candev(ndev);
952 if (err) {
953 dev_err(&pdev->dev, "register_candev() failed\n");
954 goto probe_exit_offload;
955 }
956
957 devm_can_led_init(ndev);
958
959 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
960 priv->base, (u32)ndev->irq);
961
962 return 0;
963
964probe_exit_offload:
965 can_rx_offload_del(&priv->offload);
966probe_exit_disable_clk:
967 clk_disable_unprepare(priv->clk);
968probe_exit_release_clk:
969 clk_put(priv->clk);
970probe_exit_candev:
971 free_candev(ndev);
972
973 return err;
974}
975
976static int ti_hecc_remove(struct platform_device *pdev)
977{
978 struct net_device *ndev = platform_get_drvdata(pdev);
979 struct ti_hecc_priv *priv = netdev_priv(ndev);
980
981 unregister_candev(ndev);
982 clk_disable_unprepare(priv->clk);
983 clk_put(priv->clk);
984 can_rx_offload_del(&priv->offload);
985 free_candev(ndev);
986
987 return 0;
988}
989
990#ifdef CONFIG_PM
991static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
992{
993 struct net_device *dev = platform_get_drvdata(pdev);
994 struct ti_hecc_priv *priv = netdev_priv(dev);
995
996 if (netif_running(dev)) {
997 netif_stop_queue(dev);
998 netif_device_detach(dev);
999 }
1000
1001 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1002 priv->can.state = CAN_STATE_SLEEPING;
1003
1004 clk_disable_unprepare(priv->clk);
1005
1006 return 0;
1007}
1008
1009static int ti_hecc_resume(struct platform_device *pdev)
1010{
1011 struct net_device *dev = platform_get_drvdata(pdev);
1012 struct ti_hecc_priv *priv = netdev_priv(dev);
1013 int err;
1014
1015 err = clk_prepare_enable(priv->clk);
1016 if (err)
1017 return err;
1018
1019 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1020 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1021
1022 if (netif_running(dev)) {
1023 netif_device_attach(dev);
1024 netif_start_queue(dev);
1025 }
1026
1027 return 0;
1028}
1029#else
1030#define ti_hecc_suspend NULL
1031#define ti_hecc_resume NULL
1032#endif
1033
1034/* TI HECC netdevice driver: platform driver structure */
1035static struct platform_driver ti_hecc_driver = {
1036 .driver = {
1037 .name = DRV_NAME,
1038 .of_match_table = ti_hecc_dt_ids,
1039 },
1040 .probe = ti_hecc_probe,
1041 .remove = ti_hecc_remove,
1042 .suspend = ti_hecc_suspend,
1043 .resume = ti_hecc_resume,
1044};
1045
1046module_platform_driver(ti_hecc_driver);
1047
1048MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1049MODULE_LICENSE("GPL v2");
1050MODULE_DESCRIPTION(DRV_DESC);
1051MODULE_ALIAS("platform:" DRV_NAME);