Loading...
1/*
2 * TI HECC (CAN) device driver
3 *
4 * This driver supports TI's HECC (High End CAN Controller module) and the
5 * specs for the same is available at <http://www.ti.com>
6 *
7 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation version 2.
12 *
13 * This program is distributed as is WITHOUT ANY WARRANTY of any
14 * kind, whether express or implied; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 */
19
20/*
21 * Your platform definitions should specify module ram offsets and interrupt
22 * number to use as follows:
23 *
24 * static struct ti_hecc_platform_data am3517_evm_hecc_pdata = {
25 * .scc_hecc_offset = 0,
26 * .scc_ram_offset = 0x3000,
27 * .hecc_ram_offset = 0x3000,
28 * .mbx_offset = 0x2000,
29 * .int_line = 0,
30 * .revision = 1,
31 * .transceiver_switch = hecc_phy_control,
32 * };
33 *
34 * Please see include/linux/can/platform/ti_hecc.h for description of
35 * above fields.
36 *
37 */
38
39#include <linux/module.h>
40#include <linux/kernel.h>
41#include <linux/types.h>
42#include <linux/interrupt.h>
43#include <linux/errno.h>
44#include <linux/netdevice.h>
45#include <linux/skbuff.h>
46#include <linux/platform_device.h>
47#include <linux/clk.h>
48#include <linux/io.h>
49
50#include <linux/can/dev.h>
51#include <linux/can/error.h>
52#include <linux/can/led.h>
53#include <linux/can/platform/ti_hecc.h>
54
55#define DRV_NAME "ti_hecc"
56#define HECC_MODULE_VERSION "0.7"
57MODULE_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 */
199static const struct can_bittiming_const ti_hecc_bittiming_const = {
200 .name = DRV_NAME,
201 .tseg1_min = 1,
202 .tseg1_max = 16,
203 .tseg2_min = 1,
204 .tseg2_max = 8,
205 .sjw_max = 4,
206 .brp_min = 1,
207 .brp_max = 256,
208 .brp_inc = 1,
209};
210
211struct 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
228static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
229{
230 return priv->tx_head & HECC_TX_MB_MASK;
231}
232
233static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
234{
235 return priv->tx_tail & HECC_TX_MB_MASK;
236}
237
238static 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
243static 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
248static 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
255static 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
261static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
262{
263 __raw_writel(val, priv->base + reg);
264}
265
266static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
267{
268 return __raw_readl(priv->base + reg);
269}
270
271static 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
277static 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
283static 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
288static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
289{
290 struct can_bittiming *bit_timing = &priv->can.bittiming;
291 u32 can_btc;
292
293 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
294 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
295 & 0xF) << 3;
296 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
297 if (bit_timing->brp > 4)
298 can_btc |= HECC_CANBTC_SAM;
299 else
300 netdev_warn(priv->ndev, "WARN: Triple"
301 "sampling not set due to h/w limitations");
302 }
303 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
304 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
305
306 /* ERM being set to 0 by default meaning resync at falling edge */
307
308 hecc_write(priv, HECC_CANBTC, can_btc);
309 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
310
311 return 0;
312}
313
314static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
315 int on)
316{
317 if (priv->transceiver_switch)
318 priv->transceiver_switch(on);
319}
320
321static void ti_hecc_reset(struct net_device *ndev)
322{
323 u32 cnt;
324 struct ti_hecc_priv *priv = netdev_priv(ndev);
325
326 netdev_dbg(ndev, "resetting hecc ...\n");
327 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
328
329 /* Set change control request and wait till enabled */
330 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
331
332 /*
333 * INFO: It has been observed that at times CCE bit may not be
334 * set and hw seems to be ok even if this bit is not set so
335 * timing out with a timing of 1ms to respect the specs
336 */
337 cnt = HECC_CCE_WAIT_COUNT;
338 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
339 --cnt;
340 udelay(10);
341 }
342
343 /*
344 * Note: On HECC, BTC can be programmed only in initialization mode, so
345 * it is expected that the can bittiming parameters are set via ip
346 * utility before the device is opened
347 */
348 ti_hecc_set_btc(priv);
349
350 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
351 hecc_write(priv, HECC_CANMC, 0);
352
353 /*
354 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on
355 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
356 */
357
358 /*
359 * INFO: It has been observed that at times CCE bit may not be
360 * set and hw seems to be ok even if this bit is not set so
361 */
362 cnt = HECC_CCE_WAIT_COUNT;
363 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
364 --cnt;
365 udelay(10);
366 }
367
368 /* Enable TX and RX I/O Control pins */
369 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
370 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
371
372 /* Clear registers for clean operation */
373 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
374 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
375 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
376 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
377 hecc_write(priv, HECC_CANME, 0);
378 hecc_write(priv, HECC_CANMD, 0);
379
380 /* SCC compat mode NOT supported (and not needed too) */
381 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
382}
383
384static void ti_hecc_start(struct net_device *ndev)
385{
386 struct ti_hecc_priv *priv = netdev_priv(ndev);
387 u32 cnt, mbxno, mbx_mask;
388
389 /* put HECC in initialization mode and set btc */
390 ti_hecc_reset(ndev);
391
392 priv->tx_head = priv->tx_tail = HECC_TX_MASK;
393 priv->rx_next = HECC_RX_FIRST_MBOX;
394
395 /* Enable local and global acceptance mask registers */
396 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
397
398 /* Prepare configured mailboxes to receive messages */
399 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
400 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
401 mbx_mask = BIT(mbxno);
402 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
403 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
404 hecc_write_lam(priv, mbxno, HECC_SET_REG);
405 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
406 hecc_set_bit(priv, HECC_CANME, mbx_mask);
407 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
408 }
409
410 /* Prevent message over-write & Enable interrupts */
411 hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
412 if (priv->int_line) {
413 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
414 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
415 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
416 } else {
417 hecc_write(priv, HECC_CANMIL, 0);
418 hecc_write(priv, HECC_CANGIM,
419 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
420 }
421 priv->can.state = CAN_STATE_ERROR_ACTIVE;
422}
423
424static void ti_hecc_stop(struct net_device *ndev)
425{
426 struct ti_hecc_priv *priv = netdev_priv(ndev);
427
428 /* Disable interrupts and disable mailboxes */
429 hecc_write(priv, HECC_CANGIM, 0);
430 hecc_write(priv, HECC_CANMIM, 0);
431 hecc_write(priv, HECC_CANME, 0);
432 priv->can.state = CAN_STATE_STOPPED;
433}
434
435static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
436{
437 int ret = 0;
438
439 switch (mode) {
440 case CAN_MODE_START:
441 ti_hecc_start(ndev);
442 netif_wake_queue(ndev);
443 break;
444 default:
445 ret = -EOPNOTSUPP;
446 break;
447 }
448
449 return ret;
450}
451
452static int ti_hecc_get_berr_counter(const struct net_device *ndev,
453 struct can_berr_counter *bec)
454{
455 struct ti_hecc_priv *priv = netdev_priv(ndev);
456
457 bec->txerr = hecc_read(priv, HECC_CANTEC);
458 bec->rxerr = hecc_read(priv, HECC_CANREC);
459
460 return 0;
461}
462
463/*
464 * ti_hecc_xmit: HECC Transmit
465 *
466 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
467 * priority of the mailbox for tranmission is dependent upon priority setting
468 * field in mailbox registers. The mailbox with highest value in priority field
469 * is transmitted first. Only when two mailboxes have the same value in
470 * priority field the highest numbered mailbox is transmitted first.
471 *
472 * To utilize the HECC priority feature as described above we start with the
473 * highest numbered mailbox with highest priority level and move on to the next
474 * mailbox with the same priority level and so on. Once we loop through all the
475 * transmit mailboxes we choose the next priority level (lower) and so on
476 * until we reach the lowest priority level on the lowest numbered mailbox
477 * when we stop transmission until all mailboxes are transmitted and then
478 * restart at highest numbered mailbox with highest priority.
479 *
480 * Two counters (head and tail) are used to track the next mailbox to transmit
481 * and to track the echo buffer for already transmitted mailbox. The queue
482 * is stopped when all the mailboxes are busy or when there is a priority
483 * value roll-over happens.
484 */
485static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
486{
487 struct ti_hecc_priv *priv = netdev_priv(ndev);
488 struct can_frame *cf = (struct can_frame *)skb->data;
489 u32 mbxno, mbx_mask, data;
490 unsigned long flags;
491
492 if (can_dropped_invalid_skb(ndev, skb))
493 return NETDEV_TX_OK;
494
495 mbxno = get_tx_head_mb(priv);
496 mbx_mask = BIT(mbxno);
497 spin_lock_irqsave(&priv->mbx_lock, flags);
498 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
499 spin_unlock_irqrestore(&priv->mbx_lock, flags);
500 netif_stop_queue(ndev);
501 netdev_err(priv->ndev,
502 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
503 priv->tx_head, priv->tx_tail);
504 return NETDEV_TX_BUSY;
505 }
506 spin_unlock_irqrestore(&priv->mbx_lock, flags);
507
508 /* Prepare mailbox for transmission */
509 data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
510 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
511 data |= HECC_CANMCF_RTR;
512 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
513
514 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
515 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
516 else /* Standard frame format */
517 data = (cf->can_id & CAN_SFF_MASK) << 18;
518 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
519 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
520 be32_to_cpu(*(__be32 *)(cf->data)));
521 if (cf->can_dlc > 4)
522 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
523 be32_to_cpu(*(__be32 *)(cf->data + 4)));
524 else
525 *(u32 *)(cf->data + 4) = 0;
526 can_put_echo_skb(skb, ndev, mbxno);
527
528 spin_lock_irqsave(&priv->mbx_lock, flags);
529 --priv->tx_head;
530 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
531 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
532 netif_stop_queue(ndev);
533 }
534 hecc_set_bit(priv, HECC_CANME, mbx_mask);
535 spin_unlock_irqrestore(&priv->mbx_lock, flags);
536
537 hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
538 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
539 hecc_write(priv, HECC_CANTRS, mbx_mask);
540
541 return NETDEV_TX_OK;
542}
543
544static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
545{
546 struct net_device_stats *stats = &priv->ndev->stats;
547 struct can_frame *cf;
548 struct sk_buff *skb;
549 u32 data, mbx_mask;
550 unsigned long flags;
551
552 skb = alloc_can_skb(priv->ndev, &cf);
553 if (!skb) {
554 if (printk_ratelimit())
555 netdev_err(priv->ndev,
556 "ti_hecc_rx_pkt: alloc_can_skb() failed\n");
557 return -ENOMEM;
558 }
559
560 mbx_mask = BIT(mbxno);
561 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
562 if (data & HECC_CANMID_IDE)
563 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
564 else
565 cf->can_id = (data >> 18) & CAN_SFF_MASK;
566 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
567 if (data & HECC_CANMCF_RTR)
568 cf->can_id |= CAN_RTR_FLAG;
569 cf->can_dlc = get_can_dlc(data & 0xF);
570 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
571 *(__be32 *)(cf->data) = cpu_to_be32(data);
572 if (cf->can_dlc > 4) {
573 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
574 *(__be32 *)(cf->data + 4) = cpu_to_be32(data);
575 }
576 spin_lock_irqsave(&priv->mbx_lock, flags);
577 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
578 hecc_write(priv, HECC_CANRMP, mbx_mask);
579 /* enable mailbox only if it is part of rx buffer mailboxes */
580 if (priv->rx_next < HECC_RX_BUFFER_MBOX)
581 hecc_set_bit(priv, HECC_CANME, mbx_mask);
582 spin_unlock_irqrestore(&priv->mbx_lock, flags);
583
584 stats->rx_bytes += cf->can_dlc;
585 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
586 netif_receive_skb(skb);
587 stats->rx_packets++;
588
589 return 0;
590}
591
592/*
593 * ti_hecc_rx_poll - HECC receive pkts
594 *
595 * The receive mailboxes start from highest numbered mailbox till last xmit
596 * mailbox. On CAN frame reception the hardware places the data into highest
597 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes
598 * have same filtering (ALL CAN frames) packets will arrive in the highest
599 * available RX mailbox and we need to ensure in-order packet reception.
600 *
601 * To ensure the packets are received in the right order we logically divide
602 * the RX mailboxes into main and buffer mailboxes. Packets are received as per
603 * mailbox priotity (higher to lower) in the main bank and once it is full we
604 * disable further reception into main mailboxes. While the main mailboxes are
605 * processed in NAPI, further packets are received in buffer mailboxes.
606 *
607 * We maintain a RX next mailbox counter to process packets and once all main
608 * mailboxe packets are passed to the upper stack we enable all of them but
609 * continue to process packets received in buffer mailboxes. With each packet
610 * received from buffer mailbox we enable it immediately so as to handle the
611 * overflow from higher mailboxes.
612 */
613static int ti_hecc_rx_poll(struct napi_struct *napi, int quota)
614{
615 struct net_device *ndev = napi->dev;
616 struct ti_hecc_priv *priv = netdev_priv(ndev);
617 u32 num_pkts = 0;
618 u32 mbx_mask;
619 unsigned long pending_pkts, flags;
620
621 if (!netif_running(ndev))
622 return 0;
623
624 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) &&
625 num_pkts < quota) {
626 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */
627 if (mbx_mask & pending_pkts) {
628 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0)
629 return num_pkts;
630 ++num_pkts;
631 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) {
632 break; /* pkt not received yet */
633 }
634 --priv->rx_next;
635 if (priv->rx_next == HECC_RX_BUFFER_MBOX) {
636 /* enable high bank mailboxes */
637 spin_lock_irqsave(&priv->mbx_lock, flags);
638 mbx_mask = hecc_read(priv, HECC_CANME);
639 mbx_mask |= HECC_RX_HIGH_MBOX_MASK;
640 hecc_write(priv, HECC_CANME, mbx_mask);
641 spin_unlock_irqrestore(&priv->mbx_lock, flags);
642 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
643 priv->rx_next = HECC_RX_FIRST_MBOX;
644 break;
645 }
646 }
647
648 /* Enable packet interrupt if all pkts are handled */
649 if (hecc_read(priv, HECC_CANRMP) == 0) {
650 napi_complete(napi);
651 /* Re-enable RX mailbox interrupts */
652 mbx_mask = hecc_read(priv, HECC_CANMIM);
653 mbx_mask |= HECC_TX_MBOX_MASK;
654 hecc_write(priv, HECC_CANMIM, mbx_mask);
655 }
656
657 return num_pkts;
658}
659
660static int ti_hecc_error(struct net_device *ndev, int int_status,
661 int err_status)
662{
663 struct ti_hecc_priv *priv = netdev_priv(ndev);
664 struct net_device_stats *stats = &ndev->stats;
665 struct can_frame *cf;
666 struct sk_buff *skb;
667
668 /* propagate the error condition to the can stack */
669 skb = alloc_can_err_skb(ndev, &cf);
670 if (!skb) {
671 if (printk_ratelimit())
672 netdev_err(priv->ndev,
673 "ti_hecc_error: alloc_can_err_skb() failed\n");
674 return -ENOMEM;
675 }
676
677 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
678 if ((int_status & HECC_CANGIF_BOIF) == 0) {
679 priv->can.state = CAN_STATE_ERROR_WARNING;
680 ++priv->can.can_stats.error_warning;
681 cf->can_id |= CAN_ERR_CRTL;
682 if (hecc_read(priv, HECC_CANTEC) > 96)
683 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
684 if (hecc_read(priv, HECC_CANREC) > 96)
685 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
686 }
687 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
688 netdev_dbg(priv->ndev, "Error Warning interrupt\n");
689 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
690 }
691
692 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
693 if ((int_status & HECC_CANGIF_BOIF) == 0) {
694 priv->can.state = CAN_STATE_ERROR_PASSIVE;
695 ++priv->can.can_stats.error_passive;
696 cf->can_id |= CAN_ERR_CRTL;
697 if (hecc_read(priv, HECC_CANTEC) > 127)
698 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
699 if (hecc_read(priv, HECC_CANREC) > 127)
700 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
701 }
702 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
703 netdev_dbg(priv->ndev, "Error passive interrupt\n");
704 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
705 }
706
707 /*
708 * Need to check busoff condition in error status register too to
709 * ensure warning interrupts don't hog the system
710 */
711 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
712 priv->can.state = CAN_STATE_BUS_OFF;
713 cf->can_id |= CAN_ERR_BUSOFF;
714 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
715 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
716 /* Disable all interrupts in bus-off to avoid int hog */
717 hecc_write(priv, HECC_CANGIM, 0);
718 can_bus_off(ndev);
719 }
720
721 if (err_status & HECC_BUS_ERROR) {
722 ++priv->can.can_stats.bus_error;
723 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
724 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
725 if (err_status & HECC_CANES_FE) {
726 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
727 cf->data[2] |= CAN_ERR_PROT_FORM;
728 }
729 if (err_status & HECC_CANES_BE) {
730 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
731 cf->data[2] |= CAN_ERR_PROT_BIT;
732 }
733 if (err_status & HECC_CANES_SE) {
734 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
735 cf->data[2] |= CAN_ERR_PROT_STUFF;
736 }
737 if (err_status & HECC_CANES_CRCE) {
738 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
739 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ |
740 CAN_ERR_PROT_LOC_CRC_DEL;
741 }
742 if (err_status & HECC_CANES_ACKE) {
743 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
744 cf->data[3] |= CAN_ERR_PROT_LOC_ACK |
745 CAN_ERR_PROT_LOC_ACK_DEL;
746 }
747 }
748
749 netif_rx(skb);
750 stats->rx_packets++;
751 stats->rx_bytes += cf->can_dlc;
752
753 return 0;
754}
755
756static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
757{
758 struct net_device *ndev = (struct net_device *)dev_id;
759 struct ti_hecc_priv *priv = netdev_priv(ndev);
760 struct net_device_stats *stats = &ndev->stats;
761 u32 mbxno, mbx_mask, int_status, err_status;
762 unsigned long ack, flags;
763
764 int_status = hecc_read(priv,
765 (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0);
766
767 if (!int_status)
768 return IRQ_NONE;
769
770 err_status = hecc_read(priv, HECC_CANES);
771 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
772 HECC_CANES_EP | HECC_CANES_EW))
773 ti_hecc_error(ndev, int_status, err_status);
774
775 if (int_status & HECC_CANGIF_GMIF) {
776 while (priv->tx_tail - priv->tx_head > 0) {
777 mbxno = get_tx_tail_mb(priv);
778 mbx_mask = BIT(mbxno);
779 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
780 break;
781 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
782 hecc_write(priv, HECC_CANTA, mbx_mask);
783 spin_lock_irqsave(&priv->mbx_lock, flags);
784 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
785 spin_unlock_irqrestore(&priv->mbx_lock, flags);
786 stats->tx_bytes += hecc_read_mbx(priv, mbxno,
787 HECC_CANMCF) & 0xF;
788 stats->tx_packets++;
789 can_led_event(ndev, CAN_LED_EVENT_TX);
790 can_get_echo_skb(ndev, mbxno);
791 --priv->tx_tail;
792 }
793
794 /* restart queue if wrap-up or if queue stalled on last pkt */
795 if (((priv->tx_head == priv->tx_tail) &&
796 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
797 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
798 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
799 netif_wake_queue(ndev);
800
801 /* Disable RX mailbox interrupts and let NAPI reenable them */
802 if (hecc_read(priv, HECC_CANRMP)) {
803 ack = hecc_read(priv, HECC_CANMIM);
804 ack &= BIT(HECC_MAX_TX_MBOX) - 1;
805 hecc_write(priv, HECC_CANMIM, ack);
806 napi_schedule(&priv->napi);
807 }
808 }
809
810 /* clear all interrupt conditions - read back to avoid spurious ints */
811 if (priv->int_line) {
812 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
813 int_status = hecc_read(priv, HECC_CANGIF1);
814 } else {
815 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
816 int_status = hecc_read(priv, HECC_CANGIF0);
817 }
818
819 return IRQ_HANDLED;
820}
821
822static int ti_hecc_open(struct net_device *ndev)
823{
824 struct ti_hecc_priv *priv = netdev_priv(ndev);
825 int err;
826
827 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
828 ndev->name, ndev);
829 if (err) {
830 netdev_err(ndev, "error requesting interrupt\n");
831 return err;
832 }
833
834 ti_hecc_transceiver_switch(priv, 1);
835
836 /* Open common can device */
837 err = open_candev(ndev);
838 if (err) {
839 netdev_err(ndev, "open_candev() failed %d\n", err);
840 ti_hecc_transceiver_switch(priv, 0);
841 free_irq(ndev->irq, ndev);
842 return err;
843 }
844
845 can_led_event(ndev, CAN_LED_EVENT_OPEN);
846
847 ti_hecc_start(ndev);
848 napi_enable(&priv->napi);
849 netif_start_queue(ndev);
850
851 return 0;
852}
853
854static int ti_hecc_close(struct net_device *ndev)
855{
856 struct ti_hecc_priv *priv = netdev_priv(ndev);
857
858 netif_stop_queue(ndev);
859 napi_disable(&priv->napi);
860 ti_hecc_stop(ndev);
861 free_irq(ndev->irq, ndev);
862 close_candev(ndev);
863 ti_hecc_transceiver_switch(priv, 0);
864
865 can_led_event(ndev, CAN_LED_EVENT_STOP);
866
867 return 0;
868}
869
870static const struct net_device_ops ti_hecc_netdev_ops = {
871 .ndo_open = ti_hecc_open,
872 .ndo_stop = ti_hecc_close,
873 .ndo_start_xmit = ti_hecc_xmit,
874 .ndo_change_mtu = can_change_mtu,
875};
876
877static int ti_hecc_probe(struct platform_device *pdev)
878{
879 struct net_device *ndev = (struct net_device *)0;
880 struct ti_hecc_priv *priv;
881 struct ti_hecc_platform_data *pdata;
882 struct resource *mem, *irq;
883 void __iomem *addr;
884 int err = -ENODEV;
885
886 pdata = dev_get_platdata(&pdev->dev);
887 if (!pdata) {
888 dev_err(&pdev->dev, "No platform data\n");
889 goto probe_exit;
890 }
891
892 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
893 if (!mem) {
894 dev_err(&pdev->dev, "No mem resources\n");
895 goto probe_exit;
896 }
897 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
898 if (!irq) {
899 dev_err(&pdev->dev, "No irq resource\n");
900 goto probe_exit;
901 }
902 if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) {
903 dev_err(&pdev->dev, "HECC region already claimed\n");
904 err = -EBUSY;
905 goto probe_exit;
906 }
907 addr = ioremap(mem->start, resource_size(mem));
908 if (!addr) {
909 dev_err(&pdev->dev, "ioremap failed\n");
910 err = -ENOMEM;
911 goto probe_exit_free_region;
912 }
913
914 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
915 if (!ndev) {
916 dev_err(&pdev->dev, "alloc_candev failed\n");
917 err = -ENOMEM;
918 goto probe_exit_iounmap;
919 }
920
921 priv = netdev_priv(ndev);
922 priv->ndev = ndev;
923 priv->base = addr;
924 priv->scc_ram_offset = pdata->scc_ram_offset;
925 priv->hecc_ram_offset = pdata->hecc_ram_offset;
926 priv->mbx_offset = pdata->mbx_offset;
927 priv->int_line = pdata->int_line;
928 priv->transceiver_switch = pdata->transceiver_switch;
929
930 priv->can.bittiming_const = &ti_hecc_bittiming_const;
931 priv->can.do_set_mode = ti_hecc_do_set_mode;
932 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
933 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
934
935 spin_lock_init(&priv->mbx_lock);
936 ndev->irq = irq->start;
937 ndev->flags |= IFF_ECHO;
938 platform_set_drvdata(pdev, ndev);
939 SET_NETDEV_DEV(ndev, &pdev->dev);
940 ndev->netdev_ops = &ti_hecc_netdev_ops;
941
942 priv->clk = clk_get(&pdev->dev, "hecc_ck");
943 if (IS_ERR(priv->clk)) {
944 dev_err(&pdev->dev, "No clock available\n");
945 err = PTR_ERR(priv->clk);
946 priv->clk = NULL;
947 goto probe_exit_candev;
948 }
949 priv->can.clock.freq = clk_get_rate(priv->clk);
950 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll,
951 HECC_DEF_NAPI_WEIGHT);
952
953 clk_enable(priv->clk);
954 err = register_candev(ndev);
955 if (err) {
956 dev_err(&pdev->dev, "register_candev() failed\n");
957 goto probe_exit_clk;
958 }
959
960 devm_can_led_init(ndev);
961
962 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
963 priv->base, (u32) ndev->irq);
964
965 return 0;
966
967probe_exit_clk:
968 clk_put(priv->clk);
969probe_exit_candev:
970 free_candev(ndev);
971probe_exit_iounmap:
972 iounmap(addr);
973probe_exit_free_region:
974 release_mem_region(mem->start, resource_size(mem));
975probe_exit:
976 return err;
977}
978
979static int ti_hecc_remove(struct platform_device *pdev)
980{
981 struct resource *res;
982 struct net_device *ndev = platform_get_drvdata(pdev);
983 struct ti_hecc_priv *priv = netdev_priv(ndev);
984
985 unregister_candev(ndev);
986 clk_disable(priv->clk);
987 clk_put(priv->clk);
988 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
989 iounmap(priv->base);
990 release_mem_region(res->start, resource_size(res));
991 free_candev(ndev);
992
993 return 0;
994}
995
996
997#ifdef CONFIG_PM
998static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
999{
1000 struct net_device *dev = platform_get_drvdata(pdev);
1001 struct ti_hecc_priv *priv = netdev_priv(dev);
1002
1003 if (netif_running(dev)) {
1004 netif_stop_queue(dev);
1005 netif_device_detach(dev);
1006 }
1007
1008 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1009 priv->can.state = CAN_STATE_SLEEPING;
1010
1011 clk_disable(priv->clk);
1012
1013 return 0;
1014}
1015
1016static int ti_hecc_resume(struct platform_device *pdev)
1017{
1018 struct net_device *dev = platform_get_drvdata(pdev);
1019 struct ti_hecc_priv *priv = netdev_priv(dev);
1020
1021 clk_enable(priv->clk);
1022
1023 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1024 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1025
1026 if (netif_running(dev)) {
1027 netif_device_attach(dev);
1028 netif_start_queue(dev);
1029 }
1030
1031 return 0;
1032}
1033#else
1034#define ti_hecc_suspend NULL
1035#define ti_hecc_resume NULL
1036#endif
1037
1038/* TI HECC netdevice driver: platform driver structure */
1039static struct platform_driver ti_hecc_driver = {
1040 .driver = {
1041 .name = DRV_NAME,
1042 .owner = THIS_MODULE,
1043 },
1044 .probe = ti_hecc_probe,
1045 .remove = ti_hecc_remove,
1046 .suspend = ti_hecc_suspend,
1047 .resume = ti_hecc_resume,
1048};
1049
1050module_platform_driver(ti_hecc_driver);
1051
1052MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1053MODULE_LICENSE("GPL v2");
1054MODULE_DESCRIPTION(DRV_DESC);
1055MODULE_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 tranmission 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->can_dlc | (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->can_dlc > 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);
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->can_dlc = get_can_dlc(data & 0xF);
570
571 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
572 *(__be32 *)(cf->data) = cpu_to_be32(data);
573 if (cf->can_dlc > 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);
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 *res, *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 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hecc");
882 if (!res) {
883 dev_err(&pdev->dev, "can't get IORESOURCE_MEM hecc\n");
884 return -EINVAL;
885 }
886
887 priv->base = devm_ioremap_resource(&pdev->dev, res);
888 if (IS_ERR(priv->base)) {
889 dev_err(&pdev->dev, "hecc ioremap failed\n");
890 return PTR_ERR(priv->base);
891 }
892
893 /* handle hecc-ram memory */
894 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hecc-ram");
895 if (!res) {
896 dev_err(&pdev->dev, "can't get IORESOURCE_MEM hecc-ram\n");
897 return -EINVAL;
898 }
899
900 priv->hecc_ram = devm_ioremap_resource(&pdev->dev, res);
901 if (IS_ERR(priv->hecc_ram)) {
902 dev_err(&pdev->dev, "hecc-ram ioremap failed\n");
903 return PTR_ERR(priv->hecc_ram);
904 }
905
906 /* handle mbx memory */
907 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbx");
908 if (!res) {
909 dev_err(&pdev->dev, "can't get IORESOURCE_MEM mbx\n");
910 return -EINVAL;
911 }
912
913 priv->mbx = devm_ioremap_resource(&pdev->dev, res);
914 if (IS_ERR(priv->mbx)) {
915 dev_err(&pdev->dev, "mbx ioremap failed\n");
916 return PTR_ERR(priv->mbx);
917 }
918
919 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
920 if (!irq) {
921 dev_err(&pdev->dev, "No irq resource\n");
922 goto probe_exit;
923 }
924
925 priv->ndev = ndev;
926 priv->reg_xceiver = reg_xceiver;
927 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int");
928
929 priv->can.bittiming_const = &ti_hecc_bittiming_const;
930 priv->can.do_set_mode = ti_hecc_do_set_mode;
931 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
932 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
933
934 spin_lock_init(&priv->mbx_lock);
935 ndev->irq = irq->start;
936 ndev->flags |= IFF_ECHO;
937 platform_set_drvdata(pdev, ndev);
938 SET_NETDEV_DEV(ndev, &pdev->dev);
939 ndev->netdev_ops = &ti_hecc_netdev_ops;
940
941 priv->clk = clk_get(&pdev->dev, "hecc_ck");
942 if (IS_ERR(priv->clk)) {
943 dev_err(&pdev->dev, "No clock available\n");
944 err = PTR_ERR(priv->clk);
945 priv->clk = NULL;
946 goto probe_exit_candev;
947 }
948 priv->can.clock.freq = clk_get_rate(priv->clk);
949
950 err = clk_prepare_enable(priv->clk);
951 if (err) {
952 dev_err(&pdev->dev, "clk_prepare_enable() failed\n");
953 goto probe_exit_clk;
954 }
955
956 priv->offload.mailbox_read = ti_hecc_mailbox_read;
957 priv->offload.mb_first = HECC_RX_FIRST_MBOX;
958 priv->offload.mb_last = HECC_RX_LAST_MBOX;
959 err = can_rx_offload_add_timestamp(ndev, &priv->offload);
960 if (err) {
961 dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n");
962 goto probe_exit_clk;
963 }
964
965 err = register_candev(ndev);
966 if (err) {
967 dev_err(&pdev->dev, "register_candev() failed\n");
968 goto probe_exit_offload;
969 }
970
971 devm_can_led_init(ndev);
972
973 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
974 priv->base, (u32)ndev->irq);
975
976 return 0;
977
978probe_exit_offload:
979 can_rx_offload_del(&priv->offload);
980probe_exit_clk:
981 clk_put(priv->clk);
982probe_exit_candev:
983 free_candev(ndev);
984probe_exit:
985 return err;
986}
987
988static int ti_hecc_remove(struct platform_device *pdev)
989{
990 struct net_device *ndev = platform_get_drvdata(pdev);
991 struct ti_hecc_priv *priv = netdev_priv(ndev);
992
993 unregister_candev(ndev);
994 clk_disable_unprepare(priv->clk);
995 clk_put(priv->clk);
996 can_rx_offload_del(&priv->offload);
997 free_candev(ndev);
998
999 return 0;
1000}
1001
1002#ifdef CONFIG_PM
1003static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
1004{
1005 struct net_device *dev = platform_get_drvdata(pdev);
1006 struct ti_hecc_priv *priv = netdev_priv(dev);
1007
1008 if (netif_running(dev)) {
1009 netif_stop_queue(dev);
1010 netif_device_detach(dev);
1011 }
1012
1013 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1014 priv->can.state = CAN_STATE_SLEEPING;
1015
1016 clk_disable_unprepare(priv->clk);
1017
1018 return 0;
1019}
1020
1021static int ti_hecc_resume(struct platform_device *pdev)
1022{
1023 struct net_device *dev = platform_get_drvdata(pdev);
1024 struct ti_hecc_priv *priv = netdev_priv(dev);
1025 int err;
1026
1027 err = clk_prepare_enable(priv->clk);
1028 if (err)
1029 return err;
1030
1031 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1032 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1033
1034 if (netif_running(dev)) {
1035 netif_device_attach(dev);
1036 netif_start_queue(dev);
1037 }
1038
1039 return 0;
1040}
1041#else
1042#define ti_hecc_suspend NULL
1043#define ti_hecc_resume NULL
1044#endif
1045
1046/* TI HECC netdevice driver: platform driver structure */
1047static struct platform_driver ti_hecc_driver = {
1048 .driver = {
1049 .name = DRV_NAME,
1050 .of_match_table = ti_hecc_dt_ids,
1051 },
1052 .probe = ti_hecc_probe,
1053 .remove = ti_hecc_remove,
1054 .suspend = ti_hecc_suspend,
1055 .resume = ti_hecc_resume,
1056};
1057
1058module_platform_driver(ti_hecc_driver);
1059
1060MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1061MODULE_LICENSE("GPL v2");
1062MODULE_DESCRIPTION(DRV_DESC);
1063MODULE_ALIAS("platform:" DRV_NAME);