1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI HECC (CAN) device driver
4 *
5 * This driver supports TI's HECC (High End CAN Controller module) and the
6 * specs for the same is available at <http://www.ti.com>
7 *
8 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
9 * Copyright (C) 2019 Jeroen Hofstee <jhofstee@victronenergy.com>
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/interrupt.h>
16 #include <linux/errno.h>
17 #include <linux/ethtool.h>
18 #include <linux/netdevice.h>
19 #include <linux/skbuff.h>
20 #include <linux/platform_device.h>
21 #include <linux/clk.h>
22 #include <linux/io.h>
23 #include <linux/of.h>
24 #include <linux/regulator/consumer.h>
25
26 #include <linux/can/dev.h>
27 #include <linux/can/error.h>
28 #include <linux/can/rx-offload.h>
29
30 #define DRV_NAME "ti_hecc"
31 #define HECC_MODULE_VERSION "0.7"
32 MODULE_VERSION(HECC_MODULE_VERSION);
33 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION
34
35 /* TX / RX Mailbox Configuration */
36 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */
37 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */
38
39 /* Important Note: TX mailbox configuration
40 * TX mailboxes should be restricted to the number of SKB buffers to avoid
41 * maintaining SKB buffers separately. TX mailboxes should be a power of 2
42 * for the mailbox logic to work. Top mailbox numbers are reserved for RX
43 * and lower mailboxes for TX.
44 *
45 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT
46 * 4 (default) 2
47 * 8 3
48 * 16 4
49 */
50 #define HECC_MB_TX_SHIFT 2 /* as per table above */
51 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT)
52
53 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT)
54 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT)
55 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1)
56 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK)
57
58 /* RX mailbox configuration
59 *
60 * The remaining mailboxes are used for reception and are delivered
61 * based on their timestamp, to avoid a hardware race when CANME is
62 * changed while CAN-bus traffic is being received.
63 */
64 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
65 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1)
66 #define HECC_RX_LAST_MBOX (HECC_MAX_TX_MBOX)
67
68 /* TI HECC module registers */
69 #define HECC_CANME 0x0 /* Mailbox enable */
70 #define HECC_CANMD 0x4 /* Mailbox direction */
71 #define HECC_CANTRS 0x8 /* Transmit request set */
72 #define HECC_CANTRR 0xC /* Transmit request */
73 #define HECC_CANTA 0x10 /* Transmission acknowledge */
74 #define HECC_CANAA 0x14 /* Abort acknowledge */
75 #define HECC_CANRMP 0x18 /* Receive message pending */
76 #define HECC_CANRML 0x1C /* Receive message lost */
77 #define HECC_CANRFP 0x20 /* Remote frame pending */
78 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */
79 #define HECC_CANMC 0x28 /* Master control */
80 #define HECC_CANBTC 0x2C /* Bit timing configuration */
81 #define HECC_CANES 0x30 /* Error and status */
82 #define HECC_CANTEC 0x34 /* Transmit error counter */
83 #define HECC_CANREC 0x38 /* Receive error counter */
84 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */
85 #define HECC_CANGIM 0x40 /* Global interrupt mask */
86 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */
87 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */
88 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */
89 #define HECC_CANOPC 0x50 /* Overwrite protection control */
90 #define HECC_CANTIOC 0x54 /* Transmit I/O control */
91 #define HECC_CANRIOC 0x58 /* Receive I/O control */
92 #define HECC_CANLNT 0x5C /* HECC only: Local network time */
93 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */
94 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */
95 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */
96 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */
97
98 /* TI HECC RAM registers */
99 #define HECC_CANMOTS 0x80 /* Message object time stamp */
100
101 /* Mailbox registers */
102 #define HECC_CANMID 0x0
103 #define HECC_CANMCF 0x4
104 #define HECC_CANMDL 0x8
105 #define HECC_CANMDH 0xC
106
107 #define HECC_SET_REG 0xFFFFFFFF
108 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */
109 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */
110
111 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */
112 #define HECC_CANMC_CCR BIT(12) /* Change config request */
113 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */
114 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */
115 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */
116 #define HECC_CANMC_SRES BIT(5) /* Software reset */
117
118 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */
119 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */
120
121 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */
122 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */
123 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */
124
125 #define HECC_CANES_FE BIT(24) /* form error */
126 #define HECC_CANES_BE BIT(23) /* bit error */
127 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */
128 #define HECC_CANES_CRCE BIT(21) /* CRC error */
129 #define HECC_CANES_SE BIT(20) /* stuff bit error */
130 #define HECC_CANES_ACKE BIT(19) /* ack error */
131 #define HECC_CANES_BO BIT(18) /* Bus off status */
132 #define HECC_CANES_EP BIT(17) /* Error passive status */
133 #define HECC_CANES_EW BIT(16) /* Error warning status */
134 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */
135 #define HECC_CANES_CCE BIT(4) /* Change config enabled */
136 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */
137
138 #define HECC_CANBTC_SAM BIT(7) /* sample points */
139
140 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\
141 HECC_CANES_CRCE | HECC_CANES_SE |\
142 HECC_CANES_ACKE)
143 #define HECC_CANES_FLAGS (HECC_BUS_ERROR | HECC_CANES_BO |\
144 HECC_CANES_EP | HECC_CANES_EW)
145
146 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */
147
148 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */
149 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */
150 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */
151 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */
152 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */
153 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */
154 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */
155 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */
156 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */
157 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */
158 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */
159 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */
160 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */
161 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */
162 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */
163
164 /* CAN Bittiming constants as per HECC specs */
165 static const struct can_bittiming_const ti_hecc_bittiming_const = {
166 .name = DRV_NAME,
167 .tseg1_min = 1,
168 .tseg1_max = 16,
169 .tseg2_min = 1,
170 .tseg2_max = 8,
171 .sjw_max = 4,
172 .brp_min = 1,
173 .brp_max = 256,
174 .brp_inc = 1,
175 };
176
177 struct ti_hecc_priv {
178 struct can_priv can; /* MUST be first member/field */
179 struct can_rx_offload offload;
180 struct net_device *ndev;
181 struct clk *clk;
182 void __iomem *base;
183 void __iomem *hecc_ram;
184 void __iomem *mbx;
185 bool use_hecc1int;
186 spinlock_t mbx_lock; /* CANME register needs protection */
187 u32 tx_head;
188 u32 tx_tail;
189 struct regulator *reg_xceiver;
190 };
191
get_tx_head_mb(struct ti_hecc_priv * priv)192 static inline int get_tx_head_mb(struct ti_hecc_priv *priv)
193 {
194 return priv->tx_head & HECC_TX_MB_MASK;
195 }
196
get_tx_tail_mb(struct ti_hecc_priv * priv)197 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv)
198 {
199 return priv->tx_tail & HECC_TX_MB_MASK;
200 }
201
get_tx_head_prio(struct ti_hecc_priv * priv)202 static inline int get_tx_head_prio(struct ti_hecc_priv *priv)
203 {
204 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO;
205 }
206
hecc_write_lam(struct ti_hecc_priv * priv,u32 mbxno,u32 val)207 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val)
208 {
209 __raw_writel(val, priv->hecc_ram + mbxno * 4);
210 }
211
hecc_read_stamp(struct ti_hecc_priv * priv,u32 mbxno)212 static inline u32 hecc_read_stamp(struct ti_hecc_priv *priv, u32 mbxno)
213 {
214 return __raw_readl(priv->hecc_ram + HECC_CANMOTS + mbxno * 4);
215 }
216
hecc_write_mbx(struct ti_hecc_priv * priv,u32 mbxno,u32 reg,u32 val)217 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno,
218 u32 reg, u32 val)
219 {
220 __raw_writel(val, priv->mbx + mbxno * 0x10 + reg);
221 }
222
hecc_read_mbx(struct ti_hecc_priv * priv,u32 mbxno,u32 reg)223 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg)
224 {
225 return __raw_readl(priv->mbx + mbxno * 0x10 + reg);
226 }
227
hecc_write(struct ti_hecc_priv * priv,u32 reg,u32 val)228 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val)
229 {
230 __raw_writel(val, priv->base + reg);
231 }
232
hecc_read(struct ti_hecc_priv * priv,int reg)233 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg)
234 {
235 return __raw_readl(priv->base + reg);
236 }
237
hecc_set_bit(struct ti_hecc_priv * priv,int reg,u32 bit_mask)238 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg,
239 u32 bit_mask)
240 {
241 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask);
242 }
243
hecc_clear_bit(struct ti_hecc_priv * priv,int reg,u32 bit_mask)244 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg,
245 u32 bit_mask)
246 {
247 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask);
248 }
249
hecc_get_bit(struct ti_hecc_priv * priv,int reg,u32 bit_mask)250 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
251 {
252 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
253 }
254
ti_hecc_set_btc(struct ti_hecc_priv * priv)255 static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
256 {
257 struct can_bittiming *bit_timing = &priv->can.bittiming;
258 u32 can_btc;
259
260 can_btc = (bit_timing->phase_seg2 - 1) & 0x7;
261 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1)
262 & 0xF) << 3;
263 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) {
264 if (bit_timing->brp > 4)
265 can_btc |= HECC_CANBTC_SAM;
266 else
267 netdev_warn(priv->ndev,
268 "WARN: Triple sampling not set due to h/w limitations");
269 }
270 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8;
271 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16;
272
273 /* ERM being set to 0 by default meaning resync at falling edge */
274
275 hecc_write(priv, HECC_CANBTC, can_btc);
276 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc);
277
278 return 0;
279 }
280
ti_hecc_transceiver_switch(const struct ti_hecc_priv * priv,int on)281 static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv,
282 int on)
283 {
284 if (!priv->reg_xceiver)
285 return 0;
286
287 if (on)
288 return regulator_enable(priv->reg_xceiver);
289 else
290 return regulator_disable(priv->reg_xceiver);
291 }
292
ti_hecc_reset(struct net_device * ndev)293 static void ti_hecc_reset(struct net_device *ndev)
294 {
295 u32 cnt;
296 struct ti_hecc_priv *priv = netdev_priv(ndev);
297
298 netdev_dbg(ndev, "resetting hecc ...\n");
299 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES);
300
301 /* Set change control request and wait till enabled */
302 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
303
304 /* INFO: It has been observed that at times CCE bit may not be
305 * set and hw seems to be ok even if this bit is not set so
306 * timing out with a timing of 1ms to respect the specs
307 */
308 cnt = HECC_CCE_WAIT_COUNT;
309 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
310 --cnt;
311 udelay(10);
312 }
313
314 /* Note: On HECC, BTC can be programmed only in initialization mode, so
315 * it is expected that the can bittiming parameters are set via ip
316 * utility before the device is opened
317 */
318 ti_hecc_set_btc(priv);
319
320 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */
321 hecc_write(priv, HECC_CANMC, 0);
322
323 /* INFO: CAN net stack handles bus off and hence disabling auto-bus-on
324 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO);
325 */
326
327 /* INFO: It has been observed that at times CCE bit may not be
328 * set and hw seems to be ok even if this bit is not set so
329 */
330 cnt = HECC_CCE_WAIT_COUNT;
331 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) {
332 --cnt;
333 udelay(10);
334 }
335
336 /* Enable TX and RX I/O Control pins */
337 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN);
338 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN);
339
340 /* Clear registers for clean operation */
341 hecc_write(priv, HECC_CANTA, HECC_SET_REG);
342 hecc_write(priv, HECC_CANRMP, HECC_SET_REG);
343 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
344 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
345 hecc_write(priv, HECC_CANME, 0);
346 hecc_write(priv, HECC_CANMD, 0);
347
348 /* SCC compat mode NOT supported (and not needed too) */
349 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM);
350 }
351
ti_hecc_start(struct net_device * ndev)352 static void ti_hecc_start(struct net_device *ndev)
353 {
354 struct ti_hecc_priv *priv = netdev_priv(ndev);
355 u32 cnt, mbxno, mbx_mask;
356
357 /* put HECC in initialization mode and set btc */
358 ti_hecc_reset(ndev);
359
360 priv->tx_head = HECC_TX_MASK;
361 priv->tx_tail = HECC_TX_MASK;
362
363 /* Enable local and global acceptance mask registers */
364 hecc_write(priv, HECC_CANGAM, HECC_SET_REG);
365
366 /* Prepare configured mailboxes to receive messages */
367 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) {
368 mbxno = HECC_MAX_MAILBOXES - 1 - cnt;
369 mbx_mask = BIT(mbxno);
370 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
371 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME);
372 hecc_write_lam(priv, mbxno, HECC_SET_REG);
373 hecc_set_bit(priv, HECC_CANMD, mbx_mask);
374 hecc_set_bit(priv, HECC_CANME, mbx_mask);
375 hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
376 }
377
378 /* Enable tx interrupts */
379 hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1);
380
381 /* Prevent message over-write to create a rx fifo, but not for
382 * the lowest priority mailbox, since that allows detecting
383 * overflows instead of the hardware silently dropping the
384 * messages.
385 */
386 mbx_mask = ~BIT(HECC_RX_LAST_MBOX);
387 hecc_write(priv, HECC_CANOPC, mbx_mask);
388
389 /* Enable interrupts */
390 if (priv->use_hecc1int) {
391 hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
392 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
393 HECC_CANGIM_I1EN | HECC_CANGIM_SIL);
394 } else {
395 hecc_write(priv, HECC_CANMIL, 0);
396 hecc_write(priv, HECC_CANGIM,
397 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN);
398 }
399 priv->can.state = CAN_STATE_ERROR_ACTIVE;
400 }
401
ti_hecc_stop(struct net_device * ndev)402 static void ti_hecc_stop(struct net_device *ndev)
403 {
404 struct ti_hecc_priv *priv = netdev_priv(ndev);
405
406 /* Disable the CPK; stop sending, erroring and acking */
407 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
408
409 /* Disable interrupts and disable mailboxes */
410 hecc_write(priv, HECC_CANGIM, 0);
411 hecc_write(priv, HECC_CANMIM, 0);
412 hecc_write(priv, HECC_CANME, 0);
413 priv->can.state = CAN_STATE_STOPPED;
414 }
415
ti_hecc_do_set_mode(struct net_device * ndev,enum can_mode mode)416 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode)
417 {
418 int ret = 0;
419
420 switch (mode) {
421 case CAN_MODE_START:
422 ti_hecc_start(ndev);
423 netif_wake_queue(ndev);
424 break;
425 default:
426 ret = -EOPNOTSUPP;
427 break;
428 }
429
430 return ret;
431 }
432
ti_hecc_get_berr_counter(const struct net_device * ndev,struct can_berr_counter * bec)433 static int ti_hecc_get_berr_counter(const struct net_device *ndev,
434 struct can_berr_counter *bec)
435 {
436 struct ti_hecc_priv *priv = netdev_priv(ndev);
437
438 bec->txerr = hecc_read(priv, HECC_CANTEC);
439 bec->rxerr = hecc_read(priv, HECC_CANREC);
440
441 return 0;
442 }
443
444 /* ti_hecc_xmit: HECC Transmit
445 *
446 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
447 * priority of the mailbox for transmission is dependent upon priority setting
448 * field in mailbox registers. The mailbox with highest value in priority field
449 * is transmitted first. Only when two mailboxes have the same value in
450 * priority field the highest numbered mailbox is transmitted first.
451 *
452 * To utilize the HECC priority feature as described above we start with the
453 * highest numbered mailbox with highest priority level and move on to the next
454 * mailbox with the same priority level and so on. Once we loop through all the
455 * transmit mailboxes we choose the next priority level (lower) and so on
456 * until we reach the lowest priority level on the lowest numbered mailbox
457 * when we stop transmission until all mailboxes are transmitted and then
458 * restart at highest numbered mailbox with highest priority.
459 *
460 * Two counters (head and tail) are used to track the next mailbox to transmit
461 * and to track the echo buffer for already transmitted mailbox. The queue
462 * is stopped when all the mailboxes are busy or when there is a priority
463 * value roll-over happens.
464 */
ti_hecc_xmit(struct sk_buff * skb,struct net_device * ndev)465 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
466 {
467 struct ti_hecc_priv *priv = netdev_priv(ndev);
468 struct can_frame *cf = (struct can_frame *)skb->data;
469 u32 mbxno, mbx_mask, data;
470 unsigned long flags;
471
472 if (can_dev_dropped_skb(ndev, skb))
473 return NETDEV_TX_OK;
474
475 mbxno = get_tx_head_mb(priv);
476 mbx_mask = BIT(mbxno);
477 spin_lock_irqsave(&priv->mbx_lock, flags);
478 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
479 spin_unlock_irqrestore(&priv->mbx_lock, flags);
480 netif_stop_queue(ndev);
481 netdev_err(priv->ndev,
482 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
483 priv->tx_head, priv->tx_tail);
484 return NETDEV_TX_BUSY;
485 }
486 spin_unlock_irqrestore(&priv->mbx_lock, flags);
487
488 /* Prepare mailbox for transmission */
489 data = cf->len | (get_tx_head_prio(priv) << 8);
490 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
491 data |= HECC_CANMCF_RTR;
492 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);
493
494 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
495 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
496 else /* Standard frame format */
497 data = (cf->can_id & CAN_SFF_MASK) << 18;
498 hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
499 hecc_write_mbx(priv, mbxno, HECC_CANMDL,
500 be32_to_cpu(*(__be32 *)(cf->data)));
501 if (cf->len > 4)
502 hecc_write_mbx(priv, mbxno, HECC_CANMDH,
503 be32_to_cpu(*(__be32 *)(cf->data + 4)));
504 else
505 *(u32 *)(cf->data + 4) = 0;
506 can_put_echo_skb(skb, ndev, mbxno, 0);
507
508 spin_lock_irqsave(&priv->mbx_lock, flags);
509 --priv->tx_head;
510 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
511 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
512 netif_stop_queue(ndev);
513 }
514 hecc_set_bit(priv, HECC_CANME, mbx_mask);
515 spin_unlock_irqrestore(&priv->mbx_lock, flags);
516
517 hecc_write(priv, HECC_CANTRS, mbx_mask);
518
519 return NETDEV_TX_OK;
520 }
521
522 static inline
rx_offload_to_priv(struct can_rx_offload * offload)523 struct ti_hecc_priv *rx_offload_to_priv(struct can_rx_offload *offload)
524 {
525 return container_of(offload, struct ti_hecc_priv, offload);
526 }
527
ti_hecc_mailbox_read(struct can_rx_offload * offload,unsigned int mbxno,u32 * timestamp,bool drop)528 static struct sk_buff *ti_hecc_mailbox_read(struct can_rx_offload *offload,
529 unsigned int mbxno, u32 *timestamp,
530 bool drop)
531 {
532 struct ti_hecc_priv *priv = rx_offload_to_priv(offload);
533 struct sk_buff *skb;
534 struct can_frame *cf;
535 u32 data, mbx_mask;
536
537 mbx_mask = BIT(mbxno);
538
539 if (unlikely(drop)) {
540 skb = ERR_PTR(-ENOBUFS);
541 goto mark_as_read;
542 }
543
544 skb = alloc_can_skb(offload->dev, &cf);
545 if (unlikely(!skb)) {
546 skb = ERR_PTR(-ENOMEM);
547 goto mark_as_read;
548 }
549
550 data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
551 if (data & HECC_CANMID_IDE)
552 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
553 else
554 cf->can_id = (data >> 18) & CAN_SFF_MASK;
555
556 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF);
557 if (data & HECC_CANMCF_RTR)
558 cf->can_id |= CAN_RTR_FLAG;
559 cf->len = can_cc_dlc2len(data & 0xF);
560
561 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL);
562 *(__be32 *)(cf->data) = cpu_to_be32(data);
563 if (cf->len > 4) {
564 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH);
565 *(__be32 *)(cf->data + 4) = cpu_to_be32(data);
566 }
567
568 *timestamp = hecc_read_stamp(priv, mbxno);
569
570 /* Check for FIFO overrun.
571 *
572 * All but the last RX mailbox have activated overwrite
573 * protection. So skip check for overrun, if we're not
574 * handling the last RX mailbox.
575 *
576 * As the overwrite protection for the last RX mailbox is
577 * disabled, the CAN core might update while we're reading
578 * it. This means the skb might be inconsistent.
579 *
580 * Return an error to let rx-offload discard this CAN frame.
581 */
582 if (unlikely(mbxno == HECC_RX_LAST_MBOX &&
583 hecc_read(priv, HECC_CANRML) & mbx_mask))
584 skb = ERR_PTR(-ENOBUFS);
585
586 mark_as_read:
587 hecc_write(priv, HECC_CANRMP, mbx_mask);
588
589 return skb;
590 }
591
ti_hecc_error(struct net_device * ndev,int int_status,int err_status)592 static int ti_hecc_error(struct net_device *ndev, int int_status,
593 int err_status)
594 {
595 struct ti_hecc_priv *priv = netdev_priv(ndev);
596 struct can_frame *cf;
597 struct sk_buff *skb;
598 u32 timestamp;
599 int err;
600
601 if (err_status & HECC_BUS_ERROR) {
602 /* propagate the error condition to the can stack */
603 skb = alloc_can_err_skb(ndev, &cf);
604 if (!skb) {
605 if (net_ratelimit())
606 netdev_err(priv->ndev,
607 "%s: alloc_can_err_skb() failed\n",
608 __func__);
609 return -ENOMEM;
610 }
611
612 ++priv->can.can_stats.bus_error;
613 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
614 if (err_status & HECC_CANES_FE)
615 cf->data[2] |= CAN_ERR_PROT_FORM;
616 if (err_status & HECC_CANES_BE)
617 cf->data[2] |= CAN_ERR_PROT_BIT;
618 if (err_status & HECC_CANES_SE)
619 cf->data[2] |= CAN_ERR_PROT_STUFF;
620 if (err_status & HECC_CANES_CRCE)
621 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
622 if (err_status & HECC_CANES_ACKE)
623 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
624
625 timestamp = hecc_read(priv, HECC_CANLNT);
626 err = can_rx_offload_queue_timestamp(&priv->offload, skb,
627 timestamp);
628 if (err)
629 ndev->stats.rx_fifo_errors++;
630 }
631
632 hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS);
633
634 return 0;
635 }
636
ti_hecc_change_state(struct net_device * ndev,enum can_state rx_state,enum can_state tx_state)637 static void ti_hecc_change_state(struct net_device *ndev,
638 enum can_state rx_state,
639 enum can_state tx_state)
640 {
641 struct ti_hecc_priv *priv = netdev_priv(ndev);
642 struct can_frame *cf;
643 struct sk_buff *skb;
644 u32 timestamp;
645 int err;
646
647 skb = alloc_can_err_skb(priv->ndev, &cf);
648 if (unlikely(!skb)) {
649 priv->can.state = max(tx_state, rx_state);
650 return;
651 }
652
653 can_change_state(priv->ndev, cf, tx_state, rx_state);
654
655 if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) {
656 cf->can_id |= CAN_ERR_CNT;
657 cf->data[6] = hecc_read(priv, HECC_CANTEC);
658 cf->data[7] = hecc_read(priv, HECC_CANREC);
659 }
660
661 timestamp = hecc_read(priv, HECC_CANLNT);
662 err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
663 if (err)
664 ndev->stats.rx_fifo_errors++;
665 }
666
ti_hecc_interrupt(int irq,void * dev_id)667 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
668 {
669 struct net_device *ndev = (struct net_device *)dev_id;
670 struct ti_hecc_priv *priv = netdev_priv(ndev);
671 struct net_device_stats *stats = &ndev->stats;
672 u32 mbxno, mbx_mask, int_status, err_status, stamp;
673 unsigned long flags, rx_pending;
674 u32 handled = 0;
675
676 int_status = hecc_read(priv,
677 priv->use_hecc1int ?
678 HECC_CANGIF1 : HECC_CANGIF0);
679
680 if (!int_status)
681 return IRQ_NONE;
682
683 err_status = hecc_read(priv, HECC_CANES);
684 if (unlikely(err_status & HECC_CANES_FLAGS))
685 ti_hecc_error(ndev, int_status, err_status);
686
687 if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) {
688 enum can_state rx_state, tx_state;
689 u32 rec = hecc_read(priv, HECC_CANREC);
690 u32 tec = hecc_read(priv, HECC_CANTEC);
691
692 if (int_status & HECC_CANGIF_WLIF) {
693 handled |= HECC_CANGIF_WLIF;
694 rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0;
695 tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0;
696 netdev_dbg(priv->ndev, "Error Warning interrupt\n");
697 ti_hecc_change_state(ndev, rx_state, tx_state);
698 }
699
700 if (int_status & HECC_CANGIF_EPIF) {
701 handled |= HECC_CANGIF_EPIF;
702 rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0;
703 tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0;
704 netdev_dbg(priv->ndev, "Error passive interrupt\n");
705 ti_hecc_change_state(ndev, rx_state, tx_state);
706 }
707
708 if (int_status & HECC_CANGIF_BOIF) {
709 handled |= HECC_CANGIF_BOIF;
710 rx_state = CAN_STATE_BUS_OFF;
711 tx_state = CAN_STATE_BUS_OFF;
712 netdev_dbg(priv->ndev, "Bus off interrupt\n");
713
714 /* Disable all interrupts */
715 hecc_write(priv, HECC_CANGIM, 0);
716 can_bus_off(ndev);
717 ti_hecc_change_state(ndev, rx_state, tx_state);
718 }
719 } else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) {
720 enum can_state new_state, tx_state, rx_state;
721 u32 rec = hecc_read(priv, HECC_CANREC);
722 u32 tec = hecc_read(priv, HECC_CANTEC);
723
724 if (rec >= 128 || tec >= 128)
725 new_state = CAN_STATE_ERROR_PASSIVE;
726 else if (rec >= 96 || tec >= 96)
727 new_state = CAN_STATE_ERROR_WARNING;
728 else
729 new_state = CAN_STATE_ERROR_ACTIVE;
730
731 if (new_state < priv->can.state) {
732 rx_state = rec >= tec ? new_state : 0;
733 tx_state = rec <= tec ? new_state : 0;
734 ti_hecc_change_state(ndev, rx_state, tx_state);
735 }
736 }
737
738 if (int_status & HECC_CANGIF_GMIF) {
739 while (priv->tx_tail - priv->tx_head > 0) {
740 mbxno = get_tx_tail_mb(priv);
741 mbx_mask = BIT(mbxno);
742 if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
743 break;
744 hecc_write(priv, HECC_CANTA, mbx_mask);
745 spin_lock_irqsave(&priv->mbx_lock, flags);
746 hecc_clear_bit(priv, HECC_CANME, mbx_mask);
747 spin_unlock_irqrestore(&priv->mbx_lock, flags);
748 stamp = hecc_read_stamp(priv, mbxno);
749 stats->tx_bytes +=
750 can_rx_offload_get_echo_skb_queue_timestamp(&priv->offload,
751 mbxno, stamp, NULL);
752 stats->tx_packets++;
753 --priv->tx_tail;
754 }
755
756 /* restart queue if wrap-up or if queue stalled on last pkt */
757 if ((priv->tx_head == priv->tx_tail &&
758 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) ||
759 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) &&
760 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK)))
761 netif_wake_queue(ndev);
762
763 /* offload RX mailboxes and let NAPI deliver them */
764 while ((rx_pending = hecc_read(priv, HECC_CANRMP))) {
765 can_rx_offload_irq_offload_timestamp(&priv->offload,
766 rx_pending);
767 }
768 }
769
770 /* clear all interrupt conditions - read back to avoid spurious ints */
771 if (priv->use_hecc1int) {
772 hecc_write(priv, HECC_CANGIF1, handled);
773 int_status = hecc_read(priv, HECC_CANGIF1);
774 } else {
775 hecc_write(priv, HECC_CANGIF0, handled);
776 int_status = hecc_read(priv, HECC_CANGIF0);
777 }
778
779 can_rx_offload_irq_finish(&priv->offload);
780
781 return IRQ_HANDLED;
782 }
783
ti_hecc_open(struct net_device * ndev)784 static int ti_hecc_open(struct net_device *ndev)
785 {
786 struct ti_hecc_priv *priv = netdev_priv(ndev);
787 int err;
788
789 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED,
790 ndev->name, ndev);
791 if (err) {
792 netdev_err(ndev, "error requesting interrupt\n");
793 return err;
794 }
795
796 ti_hecc_transceiver_switch(priv, 1);
797
798 /* Open common can device */
799 err = open_candev(ndev);
800 if (err) {
801 netdev_err(ndev, "open_candev() failed %d\n", err);
802 ti_hecc_transceiver_switch(priv, 0);
803 free_irq(ndev->irq, ndev);
804 return err;
805 }
806
807 ti_hecc_start(ndev);
808 can_rx_offload_enable(&priv->offload);
809 netif_start_queue(ndev);
810
811 return 0;
812 }
813
ti_hecc_close(struct net_device * ndev)814 static int ti_hecc_close(struct net_device *ndev)
815 {
816 struct ti_hecc_priv *priv = netdev_priv(ndev);
817
818 netif_stop_queue(ndev);
819 can_rx_offload_disable(&priv->offload);
820 ti_hecc_stop(ndev);
821 free_irq(ndev->irq, ndev);
822 close_candev(ndev);
823 ti_hecc_transceiver_switch(priv, 0);
824
825 return 0;
826 }
827
828 static const struct net_device_ops ti_hecc_netdev_ops = {
829 .ndo_open = ti_hecc_open,
830 .ndo_stop = ti_hecc_close,
831 .ndo_start_xmit = ti_hecc_xmit,
832 .ndo_change_mtu = can_change_mtu,
833 };
834
835 static const struct ethtool_ops ti_hecc_ethtool_ops = {
836 .get_ts_info = ethtool_op_get_ts_info,
837 };
838
839 static const struct of_device_id ti_hecc_dt_ids[] = {
840 {
841 .compatible = "ti,am3517-hecc",
842 },
843 { }
844 };
845 MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids);
846
ti_hecc_probe(struct platform_device * pdev)847 static int ti_hecc_probe(struct platform_device *pdev)
848 {
849 struct net_device *ndev = (struct net_device *)0;
850 struct ti_hecc_priv *priv;
851 struct device_node *np = pdev->dev.of_node;
852 struct regulator *reg_xceiver;
853 int err = -ENODEV;
854
855 if (!IS_ENABLED(CONFIG_OF) || !np)
856 return -EINVAL;
857
858 reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
859 if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
860 return -EPROBE_DEFER;
861 else if (IS_ERR(reg_xceiver))
862 reg_xceiver = NULL;
863
864 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX);
865 if (!ndev) {
866 dev_err(&pdev->dev, "alloc_candev failed\n");
867 return -ENOMEM;
868 }
869 priv = netdev_priv(ndev);
870
871 /* handle hecc memory */
872 priv->base = devm_platform_ioremap_resource_byname(pdev, "hecc");
873 if (IS_ERR(priv->base)) {
874 dev_err(&pdev->dev, "hecc ioremap failed\n");
875 err = PTR_ERR(priv->base);
876 goto probe_exit_candev;
877 }
878
879 /* handle hecc-ram memory */
880 priv->hecc_ram = devm_platform_ioremap_resource_byname(pdev,
881 "hecc-ram");
882 if (IS_ERR(priv->hecc_ram)) {
883 dev_err(&pdev->dev, "hecc-ram ioremap failed\n");
884 err = PTR_ERR(priv->hecc_ram);
885 goto probe_exit_candev;
886 }
887
888 /* handle mbx memory */
889 priv->mbx = devm_platform_ioremap_resource_byname(pdev, "mbx");
890 if (IS_ERR(priv->mbx)) {
891 dev_err(&pdev->dev, "mbx ioremap failed\n");
892 err = PTR_ERR(priv->mbx);
893 goto probe_exit_candev;
894 }
895
896 ndev->irq = platform_get_irq(pdev, 0);
897 if (ndev->irq < 0) {
898 err = ndev->irq;
899 goto probe_exit_candev;
900 }
901
902 priv->ndev = ndev;
903 priv->reg_xceiver = reg_xceiver;
904 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int");
905
906 priv->can.bittiming_const = &ti_hecc_bittiming_const;
907 priv->can.do_set_mode = ti_hecc_do_set_mode;
908 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
909 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
910
911 spin_lock_init(&priv->mbx_lock);
912 ndev->flags |= IFF_ECHO;
913 platform_set_drvdata(pdev, ndev);
914 SET_NETDEV_DEV(ndev, &pdev->dev);
915 ndev->netdev_ops = &ti_hecc_netdev_ops;
916 ndev->ethtool_ops = &ti_hecc_ethtool_ops;
917
918 priv->clk = clk_get(&pdev->dev, "hecc_ck");
919 if (IS_ERR(priv->clk)) {
920 dev_err(&pdev->dev, "No clock available\n");
921 err = PTR_ERR(priv->clk);
922 priv->clk = NULL;
923 goto probe_exit_candev;
924 }
925 priv->can.clock.freq = clk_get_rate(priv->clk);
926
927 err = clk_prepare_enable(priv->clk);
928 if (err) {
929 dev_err(&pdev->dev, "clk_prepare_enable() failed\n");
930 goto probe_exit_release_clk;
931 }
932
933 priv->offload.mailbox_read = ti_hecc_mailbox_read;
934 priv->offload.mb_first = HECC_RX_FIRST_MBOX;
935 priv->offload.mb_last = HECC_RX_LAST_MBOX;
936 err = can_rx_offload_add_timestamp(ndev, &priv->offload);
937 if (err) {
938 dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n");
939 goto probe_exit_disable_clk;
940 }
941
942 err = register_candev(ndev);
943 if (err) {
944 dev_err(&pdev->dev, "register_candev() failed\n");
945 goto probe_exit_offload;
946 }
947
948 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
949 priv->base, (u32)ndev->irq);
950
951 return 0;
952
953 probe_exit_offload:
954 can_rx_offload_del(&priv->offload);
955 probe_exit_disable_clk:
956 clk_disable_unprepare(priv->clk);
957 probe_exit_release_clk:
958 clk_put(priv->clk);
959 probe_exit_candev:
960 free_candev(ndev);
961
962 return err;
963 }
964
ti_hecc_remove(struct platform_device * pdev)965 static void ti_hecc_remove(struct platform_device *pdev)
966 {
967 struct net_device *ndev = platform_get_drvdata(pdev);
968 struct ti_hecc_priv *priv = netdev_priv(ndev);
969
970 unregister_candev(ndev);
971 clk_disable_unprepare(priv->clk);
972 clk_put(priv->clk);
973 can_rx_offload_del(&priv->offload);
974 free_candev(ndev);
975 }
976
977 #ifdef CONFIG_PM
ti_hecc_suspend(struct platform_device * pdev,pm_message_t state)978 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state)
979 {
980 struct net_device *dev = platform_get_drvdata(pdev);
981 struct ti_hecc_priv *priv = netdev_priv(dev);
982
983 if (netif_running(dev)) {
984 netif_stop_queue(dev);
985 netif_device_detach(dev);
986 }
987
988 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
989 priv->can.state = CAN_STATE_SLEEPING;
990
991 clk_disable_unprepare(priv->clk);
992
993 return 0;
994 }
995
ti_hecc_resume(struct platform_device * pdev)996 static int ti_hecc_resume(struct platform_device *pdev)
997 {
998 struct net_device *dev = platform_get_drvdata(pdev);
999 struct ti_hecc_priv *priv = netdev_priv(dev);
1000 int err;
1001
1002 err = clk_prepare_enable(priv->clk);
1003 if (err)
1004 return err;
1005
1006 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR);
1007 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1008
1009 if (netif_running(dev)) {
1010 netif_device_attach(dev);
1011 netif_start_queue(dev);
1012 }
1013
1014 return 0;
1015 }
1016 #else
1017 #define ti_hecc_suspend NULL
1018 #define ti_hecc_resume NULL
1019 #endif
1020
1021 /* TI HECC netdevice driver: platform driver structure */
1022 static struct platform_driver ti_hecc_driver = {
1023 .driver = {
1024 .name = DRV_NAME,
1025 .of_match_table = ti_hecc_dt_ids,
1026 },
1027 .probe = ti_hecc_probe,
1028 .remove = ti_hecc_remove,
1029 .suspend = ti_hecc_suspend,
1030 .resume = ti_hecc_resume,
1031 };
1032
1033 module_platform_driver(ti_hecc_driver);
1034
1035 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>");
1036 MODULE_LICENSE("GPL v2");
1037 MODULE_DESCRIPTION(DRV_DESC);
1038 MODULE_ALIAS("platform:" DRV_NAME);
1039