1 // SPDX-License-Identifier: GPL-2.0
2 // CAN bus driver for Bosch M_CAN controller
3 // Copyright (C) 2014 Freescale Semiconductor, Inc.
4 // Dong Aisheng <b29396@freescale.com>
5 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
7 /* Bosch M_CAN user manual can be obtained from:
8 * https://github.com/linux-can/can-doc/tree/master/m_can
11 #include <linux/bitfield.h>
12 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/netdevice.h>
18 #include <linux/of_device.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/iopoll.h>
22 #include <linux/can/dev.h>
23 #include <linux/pinctrl/consumer.h>
24 #include <linux/phy/phy.h>
28 /* registers definition */
44 /* TDCR Register only available for version >=3.1.x */
80 /* message ram configuration data length */
81 #define MRAM_CFG_LEN 8
83 /* Core Release Register (CREL) */
84 #define CREL_REL_MASK GENMASK(31, 28)
85 #define CREL_STEP_MASK GENMASK(27, 24)
86 #define CREL_SUBSTEP_MASK GENMASK(23, 20)
88 /* Data Bit Timing & Prescaler Register (DBTP) */
89 #define DBTP_TDC BIT(23)
90 #define DBTP_DBRP_MASK GENMASK(20, 16)
91 #define DBTP_DTSEG1_MASK GENMASK(12, 8)
92 #define DBTP_DTSEG2_MASK GENMASK(7, 4)
93 #define DBTP_DSJW_MASK GENMASK(3, 0)
95 /* Transmitter Delay Compensation Register (TDCR) */
96 #define TDCR_TDCO_MASK GENMASK(14, 8)
97 #define TDCR_TDCF_MASK GENMASK(6, 0)
99 /* Test Register (TEST) */
100 #define TEST_LBCK BIT(4)
102 /* CC Control Register (CCCR) */
103 #define CCCR_TXP BIT(14)
104 #define CCCR_TEST BIT(7)
105 #define CCCR_DAR BIT(6)
106 #define CCCR_MON BIT(5)
107 #define CCCR_CSR BIT(4)
108 #define CCCR_CSA BIT(3)
109 #define CCCR_ASM BIT(2)
110 #define CCCR_CCE BIT(1)
111 #define CCCR_INIT BIT(0)
112 /* for version 3.0.x */
113 #define CCCR_CMR_MASK GENMASK(11, 10)
114 #define CCCR_CMR_CANFD 0x1
115 #define CCCR_CMR_CANFD_BRS 0x2
116 #define CCCR_CMR_CAN 0x3
117 #define CCCR_CME_MASK GENMASK(9, 8)
118 #define CCCR_CME_CAN 0
119 #define CCCR_CME_CANFD 0x1
120 #define CCCR_CME_CANFD_BRS 0x2
121 /* for version >=3.1.x */
122 #define CCCR_EFBI BIT(13)
123 #define CCCR_PXHD BIT(12)
124 #define CCCR_BRSE BIT(9)
125 #define CCCR_FDOE BIT(8)
126 /* for version >=3.2.x */
127 #define CCCR_NISO BIT(15)
128 /* for version >=3.3.x */
129 #define CCCR_WMM BIT(11)
130 #define CCCR_UTSU BIT(10)
132 /* Nominal Bit Timing & Prescaler Register (NBTP) */
133 #define NBTP_NSJW_MASK GENMASK(31, 25)
134 #define NBTP_NBRP_MASK GENMASK(24, 16)
135 #define NBTP_NTSEG1_MASK GENMASK(15, 8)
136 #define NBTP_NTSEG2_MASK GENMASK(6, 0)
138 /* Timestamp Counter Configuration Register (TSCC) */
139 #define TSCC_TCP_MASK GENMASK(19, 16)
140 #define TSCC_TSS_MASK GENMASK(1, 0)
141 #define TSCC_TSS_DISABLE 0x0
142 #define TSCC_TSS_INTERNAL 0x1
143 #define TSCC_TSS_EXTERNAL 0x2
145 /* Timestamp Counter Value Register (TSCV) */
146 #define TSCV_TSC_MASK GENMASK(15, 0)
148 /* Error Counter Register (ECR) */
149 #define ECR_RP BIT(15)
150 #define ECR_REC_MASK GENMASK(14, 8)
151 #define ECR_TEC_MASK GENMASK(7, 0)
153 /* Protocol Status Register (PSR) */
154 #define PSR_BO BIT(7)
155 #define PSR_EW BIT(6)
156 #define PSR_EP BIT(5)
157 #define PSR_LEC_MASK GENMASK(2, 0)
159 /* Interrupt Register (IR) */
160 #define IR_ALL_INT 0xffffffff
162 /* Renamed bits for versions > 3.1.x */
163 #define IR_ARA BIT(29)
164 #define IR_PED BIT(28)
165 #define IR_PEA BIT(27)
167 /* Bits for version 3.0.x */
168 #define IR_STE BIT(31)
169 #define IR_FOE BIT(30)
170 #define IR_ACKE BIT(29)
171 #define IR_BE BIT(28)
172 #define IR_CRCE BIT(27)
173 #define IR_WDI BIT(26)
174 #define IR_BO BIT(25)
175 #define IR_EW BIT(24)
176 #define IR_EP BIT(23)
177 #define IR_ELO BIT(22)
178 #define IR_BEU BIT(21)
179 #define IR_BEC BIT(20)
180 #define IR_DRX BIT(19)
181 #define IR_TOO BIT(18)
182 #define IR_MRAF BIT(17)
183 #define IR_TSW BIT(16)
184 #define IR_TEFL BIT(15)
185 #define IR_TEFF BIT(14)
186 #define IR_TEFW BIT(13)
187 #define IR_TEFN BIT(12)
188 #define IR_TFE BIT(11)
189 #define IR_TCF BIT(10)
191 #define IR_HPM BIT(8)
192 #define IR_RF1L BIT(7)
193 #define IR_RF1F BIT(6)
194 #define IR_RF1W BIT(5)
195 #define IR_RF1N BIT(4)
196 #define IR_RF0L BIT(3)
197 #define IR_RF0F BIT(2)
198 #define IR_RF0W BIT(1)
199 #define IR_RF0N BIT(0)
200 #define IR_ERR_STATE (IR_BO | IR_EW | IR_EP)
202 /* Interrupts for version 3.0.x */
203 #define IR_ERR_LEC_30X (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
204 #define IR_ERR_BUS_30X (IR_ERR_LEC_30X | IR_WDI | IR_BEU | IR_BEC | \
205 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
207 #define IR_ERR_ALL_30X (IR_ERR_STATE | IR_ERR_BUS_30X)
209 /* Interrupts for version >= 3.1.x */
210 #define IR_ERR_LEC_31X (IR_PED | IR_PEA)
211 #define IR_ERR_BUS_31X (IR_ERR_LEC_31X | IR_WDI | IR_BEU | IR_BEC | \
212 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
214 #define IR_ERR_ALL_31X (IR_ERR_STATE | IR_ERR_BUS_31X)
216 /* Interrupt Line Select (ILS) */
217 #define ILS_ALL_INT0 0x0
218 #define ILS_ALL_INT1 0xFFFFFFFF
220 /* Interrupt Line Enable (ILE) */
221 #define ILE_EINT1 BIT(1)
222 #define ILE_EINT0 BIT(0)
224 /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
225 #define RXFC_FWM_MASK GENMASK(30, 24)
226 #define RXFC_FS_MASK GENMASK(22, 16)
228 /* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
229 #define RXFS_RFL BIT(25)
230 #define RXFS_FF BIT(24)
231 #define RXFS_FPI_MASK GENMASK(21, 16)
232 #define RXFS_FGI_MASK GENMASK(13, 8)
233 #define RXFS_FFL_MASK GENMASK(6, 0)
235 /* Rx Buffer / FIFO Element Size Configuration (RXESC) */
236 #define RXESC_RBDS_MASK GENMASK(10, 8)
237 #define RXESC_F1DS_MASK GENMASK(6, 4)
238 #define RXESC_F0DS_MASK GENMASK(2, 0)
239 #define RXESC_64B 0x7
241 /* Tx Buffer Configuration (TXBC) */
242 #define TXBC_TFQS_MASK GENMASK(29, 24)
243 #define TXBC_NDTB_MASK GENMASK(21, 16)
245 /* Tx FIFO/Queue Status (TXFQS) */
246 #define TXFQS_TFQF BIT(21)
247 #define TXFQS_TFQPI_MASK GENMASK(20, 16)
248 #define TXFQS_TFGI_MASK GENMASK(12, 8)
249 #define TXFQS_TFFL_MASK GENMASK(5, 0)
251 /* Tx Buffer Element Size Configuration (TXESC) */
252 #define TXESC_TBDS_MASK GENMASK(2, 0)
253 #define TXESC_TBDS_64B 0x7
255 /* Tx Event FIFO Configuration (TXEFC) */
256 #define TXEFC_EFS_MASK GENMASK(21, 16)
258 /* Tx Event FIFO Status (TXEFS) */
259 #define TXEFS_TEFL BIT(25)
260 #define TXEFS_EFF BIT(24)
261 #define TXEFS_EFGI_MASK GENMASK(12, 8)
262 #define TXEFS_EFFL_MASK GENMASK(5, 0)
264 /* Tx Event FIFO Acknowledge (TXEFA) */
265 #define TXEFA_EFAI_MASK GENMASK(4, 0)
267 /* Message RAM Configuration (in bytes) */
268 #define SIDF_ELEMENT_SIZE 4
269 #define XIDF_ELEMENT_SIZE 8
270 #define RXF0_ELEMENT_SIZE 72
271 #define RXF1_ELEMENT_SIZE 72
272 #define RXB_ELEMENT_SIZE 72
273 #define TXE_ELEMENT_SIZE 8
274 #define TXB_ELEMENT_SIZE 72
276 /* Message RAM Elements */
277 #define M_CAN_FIFO_ID 0x0
278 #define M_CAN_FIFO_DLC 0x4
279 #define M_CAN_FIFO_DATA 0x8
281 /* Rx Buffer Element */
283 #define RX_BUF_ESI BIT(31)
284 #define RX_BUF_XTD BIT(30)
285 #define RX_BUF_RTR BIT(29)
287 #define RX_BUF_ANMF BIT(31)
288 #define RX_BUF_FDF BIT(21)
289 #define RX_BUF_BRS BIT(20)
290 #define RX_BUF_RXTS_MASK GENMASK(15, 0)
292 /* Tx Buffer Element */
294 #define TX_BUF_ESI BIT(31)
295 #define TX_BUF_XTD BIT(30)
296 #define TX_BUF_RTR BIT(29)
298 #define TX_BUF_EFC BIT(23)
299 #define TX_BUF_FDF BIT(21)
300 #define TX_BUF_BRS BIT(20)
301 #define TX_BUF_MM_MASK GENMASK(31, 24)
302 #define TX_BUF_DLC_MASK GENMASK(19, 16)
304 /* Tx event FIFO Element */
306 #define TX_EVENT_MM_MASK GENMASK(31, 24)
307 #define TX_EVENT_TXTS_MASK GENMASK(15, 0)
309 /* The ID and DLC registers are adjacent in M_CAN FIFO memory,
310 * and we can save a (potentially slow) bus round trip by combining
311 * reads and writes to them.
318 static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
320 return cdev->ops->read_reg(cdev, reg);
323 static inline void m_can_write(struct m_can_classdev *cdev, enum m_can_reg reg,
326 cdev->ops->write_reg(cdev, reg, val);
330 m_can_fifo_read(struct m_can_classdev *cdev,
331 u32 fgi, unsigned int offset, void *val, size_t val_count)
333 u32 addr_offset = cdev->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
339 return cdev->ops->read_fifo(cdev, addr_offset, val, val_count);
343 m_can_fifo_write(struct m_can_classdev *cdev,
344 u32 fpi, unsigned int offset, const void *val, size_t val_count)
346 u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
352 return cdev->ops->write_fifo(cdev, addr_offset, val, val_count);
355 static inline int m_can_fifo_write_no_off(struct m_can_classdev *cdev,
358 return cdev->ops->write_fifo(cdev, fpi, &val, 1);
362 m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
364 u32 addr_offset = cdev->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
367 return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
370 static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
372 return !!(m_can_read(cdev, M_CAN_TXFQS) & TXFQS_TFQF);
375 static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
377 u32 cccr = m_can_read(cdev, M_CAN_CCCR);
381 /* Clear the Clock stop request if it was set */
386 /* enable m_can configuration */
387 m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
389 /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
390 m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
392 m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
395 /* there's a delay for module initialization */
397 val = CCCR_INIT | CCCR_CCE;
399 while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
401 netdev_warn(cdev->net, "Failed to init module\n");
409 static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
411 /* Only interrupt line 0 is used in this driver */
412 m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
415 static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
417 m_can_write(cdev, M_CAN_ILE, 0x0);
420 /* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
423 static u32 m_can_get_timestamp(struct m_can_classdev *cdev)
428 tscv = m_can_read(cdev, M_CAN_TSCV);
429 tsc = FIELD_GET(TSCV_TSC_MASK, tscv);
434 static void m_can_clean(struct net_device *net)
436 struct m_can_classdev *cdev = netdev_priv(net);
441 net->stats.tx_errors++;
442 if (cdev->version > 30)
443 putidx = FIELD_GET(TXFQS_TFQPI_MASK,
444 m_can_read(cdev, M_CAN_TXFQS));
446 can_free_echo_skb(cdev->net, putidx, NULL);
451 /* For peripherals, pass skb to rx-offload, which will push skb from
452 * napi. For non-peripherals, RX is done in napi already, so push
453 * directly. timestamp is used to ensure good skb ordering in
454 * rx-offload and is ignored for non-peripherals.
456 static void m_can_receive_skb(struct m_can_classdev *cdev,
460 if (cdev->is_peripheral) {
461 struct net_device_stats *stats = &cdev->net->stats;
464 err = can_rx_offload_queue_timestamp(&cdev->offload, skb,
467 stats->rx_fifo_errors++;
469 netif_receive_skb(skb);
473 static int m_can_read_fifo(struct net_device *dev, u32 rxfs)
475 struct net_device_stats *stats = &dev->stats;
476 struct m_can_classdev *cdev = netdev_priv(dev);
477 struct canfd_frame *cf;
479 struct id_and_dlc fifo_header;
484 /* calculate the fifo get index for where to read data */
485 fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
486 err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID, &fifo_header, 2);
490 if (fifo_header.dlc & RX_BUF_FDF)
491 skb = alloc_canfd_skb(dev, &cf);
493 skb = alloc_can_skb(dev, (struct can_frame **)&cf);
499 if (fifo_header.dlc & RX_BUF_FDF)
500 cf->len = can_fd_dlc2len((fifo_header.dlc >> 16) & 0x0F);
502 cf->len = can_cc_dlc2len((fifo_header.dlc >> 16) & 0x0F);
504 if (fifo_header.id & RX_BUF_XTD)
505 cf->can_id = (fifo_header.id & CAN_EFF_MASK) | CAN_EFF_FLAG;
507 cf->can_id = (fifo_header.id >> 18) & CAN_SFF_MASK;
509 if (fifo_header.id & RX_BUF_ESI) {
510 cf->flags |= CANFD_ESI;
511 netdev_dbg(dev, "ESI Error\n");
514 if (!(fifo_header.dlc & RX_BUF_FDF) && (fifo_header.id & RX_BUF_RTR)) {
515 cf->can_id |= CAN_RTR_FLAG;
517 if (fifo_header.dlc & RX_BUF_BRS)
518 cf->flags |= CANFD_BRS;
520 err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA,
521 cf->data, DIV_ROUND_UP(cf->len, 4));
525 stats->rx_bytes += cf->len;
529 /* acknowledge rx fifo 0 */
530 m_can_write(cdev, M_CAN_RXF0A, fgi);
532 timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;
534 m_can_receive_skb(cdev, skb, timestamp);
541 netdev_err(dev, "FIFO read returned %d\n", err);
545 static int m_can_do_rx_poll(struct net_device *dev, int quota)
547 struct m_can_classdev *cdev = netdev_priv(dev);
552 rxfs = m_can_read(cdev, M_CAN_RXF0S);
553 if (!(rxfs & RXFS_FFL_MASK)) {
554 netdev_dbg(dev, "no messages in fifo0\n");
558 while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
559 err = m_can_read_fifo(dev, rxfs);
565 rxfs = m_can_read(cdev, M_CAN_RXF0S);
571 static int m_can_handle_lost_msg(struct net_device *dev)
573 struct m_can_classdev *cdev = netdev_priv(dev);
574 struct net_device_stats *stats = &dev->stats;
576 struct can_frame *frame;
579 netdev_err(dev, "msg lost in rxf0\n");
582 stats->rx_over_errors++;
584 skb = alloc_can_err_skb(dev, &frame);
588 frame->can_id |= CAN_ERR_CRTL;
589 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
591 if (cdev->is_peripheral)
592 timestamp = m_can_get_timestamp(cdev);
594 m_can_receive_skb(cdev, skb, timestamp);
599 static int m_can_handle_lec_err(struct net_device *dev,
600 enum m_can_lec_type lec_type)
602 struct m_can_classdev *cdev = netdev_priv(dev);
603 struct net_device_stats *stats = &dev->stats;
604 struct can_frame *cf;
608 cdev->can.can_stats.bus_error++;
611 /* propagate the error condition to the CAN stack */
612 skb = alloc_can_err_skb(dev, &cf);
616 /* check for 'last error code' which tells us the
617 * type of the last error to occur on the CAN bus
619 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
622 case LEC_STUFF_ERROR:
623 netdev_dbg(dev, "stuff error\n");
624 cf->data[2] |= CAN_ERR_PROT_STUFF;
627 netdev_dbg(dev, "form error\n");
628 cf->data[2] |= CAN_ERR_PROT_FORM;
631 netdev_dbg(dev, "ack error\n");
632 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
635 netdev_dbg(dev, "bit1 error\n");
636 cf->data[2] |= CAN_ERR_PROT_BIT1;
639 netdev_dbg(dev, "bit0 error\n");
640 cf->data[2] |= CAN_ERR_PROT_BIT0;
643 netdev_dbg(dev, "CRC error\n");
644 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
650 if (cdev->is_peripheral)
651 timestamp = m_can_get_timestamp(cdev);
653 m_can_receive_skb(cdev, skb, timestamp);
658 static int __m_can_get_berr_counter(const struct net_device *dev,
659 struct can_berr_counter *bec)
661 struct m_can_classdev *cdev = netdev_priv(dev);
664 ecr = m_can_read(cdev, M_CAN_ECR);
665 bec->rxerr = FIELD_GET(ECR_REC_MASK, ecr);
666 bec->txerr = FIELD_GET(ECR_TEC_MASK, ecr);
671 static int m_can_clk_start(struct m_can_classdev *cdev)
673 if (cdev->pm_clock_support == 0)
676 return pm_runtime_resume_and_get(cdev->dev);
679 static void m_can_clk_stop(struct m_can_classdev *cdev)
681 if (cdev->pm_clock_support)
682 pm_runtime_put_sync(cdev->dev);
685 static int m_can_get_berr_counter(const struct net_device *dev,
686 struct can_berr_counter *bec)
688 struct m_can_classdev *cdev = netdev_priv(dev);
691 err = m_can_clk_start(cdev);
695 __m_can_get_berr_counter(dev, bec);
697 m_can_clk_stop(cdev);
702 static int m_can_handle_state_change(struct net_device *dev,
703 enum can_state new_state)
705 struct m_can_classdev *cdev = netdev_priv(dev);
706 struct can_frame *cf;
708 struct can_berr_counter bec;
713 case CAN_STATE_ERROR_WARNING:
714 /* error warning state */
715 cdev->can.can_stats.error_warning++;
716 cdev->can.state = CAN_STATE_ERROR_WARNING;
718 case CAN_STATE_ERROR_PASSIVE:
719 /* error passive state */
720 cdev->can.can_stats.error_passive++;
721 cdev->can.state = CAN_STATE_ERROR_PASSIVE;
723 case CAN_STATE_BUS_OFF:
725 cdev->can.state = CAN_STATE_BUS_OFF;
726 m_can_disable_all_interrupts(cdev);
727 cdev->can.can_stats.bus_off++;
734 /* propagate the error condition to the CAN stack */
735 skb = alloc_can_err_skb(dev, &cf);
739 __m_can_get_berr_counter(dev, &bec);
742 case CAN_STATE_ERROR_WARNING:
743 /* error warning state */
744 cf->can_id |= CAN_ERR_CRTL;
745 cf->data[1] = (bec.txerr > bec.rxerr) ?
746 CAN_ERR_CRTL_TX_WARNING :
747 CAN_ERR_CRTL_RX_WARNING;
748 cf->data[6] = bec.txerr;
749 cf->data[7] = bec.rxerr;
751 case CAN_STATE_ERROR_PASSIVE:
752 /* error passive state */
753 cf->can_id |= CAN_ERR_CRTL;
754 ecr = m_can_read(cdev, M_CAN_ECR);
756 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
758 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
759 cf->data[6] = bec.txerr;
760 cf->data[7] = bec.rxerr;
762 case CAN_STATE_BUS_OFF:
764 cf->can_id |= CAN_ERR_BUSOFF;
770 if (cdev->is_peripheral)
771 timestamp = m_can_get_timestamp(cdev);
773 m_can_receive_skb(cdev, skb, timestamp);
778 static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
780 struct m_can_classdev *cdev = netdev_priv(dev);
783 if (psr & PSR_EW && cdev->can.state != CAN_STATE_ERROR_WARNING) {
784 netdev_dbg(dev, "entered error warning state\n");
785 work_done += m_can_handle_state_change(dev,
786 CAN_STATE_ERROR_WARNING);
789 if (psr & PSR_EP && cdev->can.state != CAN_STATE_ERROR_PASSIVE) {
790 netdev_dbg(dev, "entered error passive state\n");
791 work_done += m_can_handle_state_change(dev,
792 CAN_STATE_ERROR_PASSIVE);
795 if (psr & PSR_BO && cdev->can.state != CAN_STATE_BUS_OFF) {
796 netdev_dbg(dev, "entered error bus off state\n");
797 work_done += m_can_handle_state_change(dev,
804 static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
806 if (irqstatus & IR_WDI)
807 netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
808 if (irqstatus & IR_BEU)
809 netdev_err(dev, "Bit Error Uncorrected\n");
810 if (irqstatus & IR_BEC)
811 netdev_err(dev, "Bit Error Corrected\n");
812 if (irqstatus & IR_TOO)
813 netdev_err(dev, "Timeout reached\n");
814 if (irqstatus & IR_MRAF)
815 netdev_err(dev, "Message RAM access failure occurred\n");
818 static inline bool is_lec_err(u32 psr)
822 return psr && (psr != LEC_UNUSED);
825 static inline bool m_can_is_protocol_err(u32 irqstatus)
827 return irqstatus & IR_ERR_LEC_31X;
830 static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
832 struct net_device_stats *stats = &dev->stats;
833 struct m_can_classdev *cdev = netdev_priv(dev);
834 struct can_frame *cf;
838 /* propagate the error condition to the CAN stack */
839 skb = alloc_can_err_skb(dev, &cf);
841 /* update tx error stats since there is protocol error */
844 /* update arbitration lost status */
845 if (cdev->version >= 31 && (irqstatus & IR_PEA)) {
846 netdev_dbg(dev, "Protocol error in Arbitration fail\n");
847 cdev->can.can_stats.arbitration_lost++;
849 cf->can_id |= CAN_ERR_LOSTARB;
850 cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
854 if (unlikely(!skb)) {
855 netdev_dbg(dev, "allocation of skb failed\n");
859 if (cdev->is_peripheral)
860 timestamp = m_can_get_timestamp(cdev);
862 m_can_receive_skb(cdev, skb, timestamp);
867 static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
870 struct m_can_classdev *cdev = netdev_priv(dev);
873 if (irqstatus & IR_RF0L)
874 work_done += m_can_handle_lost_msg(dev);
876 /* handle lec errors on the bus */
877 if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
879 work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
881 /* handle protocol errors in arbitration phase */
882 if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
883 m_can_is_protocol_err(irqstatus))
884 work_done += m_can_handle_protocol_error(dev, irqstatus);
886 /* other unproccessed error interrupts */
887 m_can_handle_other_err(dev, irqstatus);
892 static int m_can_rx_handler(struct net_device *dev, int quota)
894 struct m_can_classdev *cdev = netdev_priv(dev);
899 irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
903 /* Errata workaround for issue "Needless activation of MRAF irq"
904 * During frame reception while the MCAN is in Error Passive state
905 * and the Receive Error Counter has the value MCAN_ECR.REC = 127,
906 * it may happen that MCAN_IR.MRAF is set although there was no
907 * Message RAM access failure.
908 * If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated
909 * The Message RAM Access Failure interrupt routine needs to check
910 * whether MCAN_ECR.RP = ’1’ and MCAN_ECR.REC = 127.
911 * In this case, reset MCAN_IR.MRAF. No further action is required.
913 if (cdev->version <= 31 && irqstatus & IR_MRAF &&
914 m_can_read(cdev, M_CAN_ECR) & ECR_RP) {
915 struct can_berr_counter bec;
917 __m_can_get_berr_counter(dev, &bec);
918 if (bec.rxerr == 127) {
919 m_can_write(cdev, M_CAN_IR, IR_MRAF);
920 irqstatus &= ~IR_MRAF;
924 psr = m_can_read(cdev, M_CAN_PSR);
926 if (irqstatus & IR_ERR_STATE)
927 work_done += m_can_handle_state_errors(dev, psr);
929 if (irqstatus & IR_ERR_BUS_30X)
930 work_done += m_can_handle_bus_errors(dev, irqstatus, psr);
932 if (irqstatus & IR_RF0N) {
933 rx_work_or_err = m_can_do_rx_poll(dev, (quota - work_done));
934 if (rx_work_or_err < 0)
935 return rx_work_or_err;
937 work_done += rx_work_or_err;
943 static int m_can_rx_peripheral(struct net_device *dev)
945 struct m_can_classdev *cdev = netdev_priv(dev);
948 work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT);
950 /* Don't re-enable interrupts if the driver had a fatal error
951 * (e.g., FIFO read failure).
954 m_can_enable_all_interrupts(cdev);
959 static int m_can_poll(struct napi_struct *napi, int quota)
961 struct net_device *dev = napi->dev;
962 struct m_can_classdev *cdev = netdev_priv(dev);
965 work_done = m_can_rx_handler(dev, quota);
967 /* Don't re-enable interrupts if the driver had a fatal error
968 * (e.g., FIFO read failure).
970 if (work_done >= 0 && work_done < quota) {
971 napi_complete_done(napi, work_done);
972 m_can_enable_all_interrupts(cdev);
978 /* Echo tx skb and update net stats. Peripherals use rx-offload for
979 * echo. timestamp is used for peripherals to ensure correct ordering
980 * by rx-offload, and is ignored for non-peripherals.
982 static void m_can_tx_update_stats(struct m_can_classdev *cdev,
983 unsigned int msg_mark,
986 struct net_device *dev = cdev->net;
987 struct net_device_stats *stats = &dev->stats;
989 if (cdev->is_peripheral)
991 can_rx_offload_get_echo_skb(&cdev->offload,
996 stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
1001 static int m_can_echo_tx_event(struct net_device *dev)
1007 unsigned int msg_mark;
1009 struct m_can_classdev *cdev = netdev_priv(dev);
1011 /* read tx event fifo status */
1012 m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
1014 /* Get Tx Event fifo element count */
1015 txe_count = FIELD_GET(TXEFS_EFFL_MASK, m_can_txefs);
1017 /* Get and process all sent elements */
1018 for (i = 0; i < txe_count; i++) {
1019 u32 txe, timestamp = 0;
1022 /* retrieve get index */
1023 fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_read(cdev, M_CAN_TXEFS));
1025 /* get message marker, timestamp */
1026 err = m_can_txe_fifo_read(cdev, fgi, 4, &txe);
1028 netdev_err(dev, "TXE FIFO read returned %d\n", err);
1032 msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
1033 timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;
1035 /* ack txe element */
1036 m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
1040 m_can_tx_update_stats(cdev, msg_mark, timestamp);
1046 static irqreturn_t m_can_isr(int irq, void *dev_id)
1048 struct net_device *dev = (struct net_device *)dev_id;
1049 struct m_can_classdev *cdev = netdev_priv(dev);
1052 if (pm_runtime_suspended(cdev->dev))
1054 ir = m_can_read(cdev, M_CAN_IR);
1059 if (ir & IR_ALL_INT)
1060 m_can_write(cdev, M_CAN_IR, ir);
1062 if (cdev->ops->clear_interrupts)
1063 cdev->ops->clear_interrupts(cdev);
1065 /* schedule NAPI in case of
1067 * - state change IRQ
1068 * - bus error IRQ and bus error reporting
1070 if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
1071 cdev->irqstatus = ir;
1072 m_can_disable_all_interrupts(cdev);
1073 if (!cdev->is_peripheral)
1074 napi_schedule(&cdev->napi);
1075 else if (m_can_rx_peripheral(dev) < 0)
1079 if (cdev->version == 30) {
1081 /* Transmission Complete Interrupt*/
1084 if (cdev->is_peripheral)
1085 timestamp = m_can_get_timestamp(cdev);
1086 m_can_tx_update_stats(cdev, 0, timestamp);
1087 netif_wake_queue(dev);
1091 /* New TX FIFO Element arrived */
1092 if (m_can_echo_tx_event(dev) != 0)
1095 if (netif_queue_stopped(dev) &&
1096 !m_can_tx_fifo_full(cdev))
1097 netif_wake_queue(dev);
1101 if (cdev->is_peripheral)
1102 can_rx_offload_threaded_irq_finish(&cdev->offload);
1107 m_can_disable_all_interrupts(cdev);
1111 static const struct can_bittiming_const m_can_bittiming_const_30X = {
1112 .name = KBUILD_MODNAME,
1113 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1115 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1123 static const struct can_bittiming_const m_can_data_bittiming_const_30X = {
1124 .name = KBUILD_MODNAME,
1125 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1127 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1135 static const struct can_bittiming_const m_can_bittiming_const_31X = {
1136 .name = KBUILD_MODNAME,
1137 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1139 .tseg2_min = 2, /* Time segment 2 = phase_seg2 */
1147 static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
1148 .name = KBUILD_MODNAME,
1149 .tseg1_min = 1, /* Time segment 1 = prop_seg + phase_seg1 */
1151 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1159 static int m_can_set_bittiming(struct net_device *dev)
1161 struct m_can_classdev *cdev = netdev_priv(dev);
1162 const struct can_bittiming *bt = &cdev->can.bittiming;
1163 const struct can_bittiming *dbt = &cdev->can.data_bittiming;
1164 u16 brp, sjw, tseg1, tseg2;
1169 tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
1170 tseg2 = bt->phase_seg2 - 1;
1171 reg_btp = FIELD_PREP(NBTP_NBRP_MASK, brp) |
1172 FIELD_PREP(NBTP_NSJW_MASK, sjw) |
1173 FIELD_PREP(NBTP_NTSEG1_MASK, tseg1) |
1174 FIELD_PREP(NBTP_NTSEG2_MASK, tseg2);
1175 m_can_write(cdev, M_CAN_NBTP, reg_btp);
1177 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1181 tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
1182 tseg2 = dbt->phase_seg2 - 1;
1184 /* TDC is only needed for bitrates beyond 2.5 MBit/s.
1185 * This is mentioned in the "Bit Time Requirements for CAN FD"
1186 * paper presented at the International CAN Conference 2013
1188 if (dbt->bitrate > 2500000) {
1191 /* Use the same value of secondary sampling point
1192 * as the data sampling point
1194 ssp = dbt->sample_point;
1196 /* Equation based on Bosch's M_CAN User Manual's
1197 * Transmitter Delay Compensation Section
1199 tdco = (cdev->can.clock.freq / 1000) *
1202 /* Max valid TDCO value is 127 */
1204 netdev_warn(dev, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
1209 reg_btp |= DBTP_TDC;
1210 m_can_write(cdev, M_CAN_TDCR,
1211 FIELD_PREP(TDCR_TDCO_MASK, tdco));
1214 reg_btp |= FIELD_PREP(DBTP_DBRP_MASK, brp) |
1215 FIELD_PREP(DBTP_DSJW_MASK, sjw) |
1216 FIELD_PREP(DBTP_DTSEG1_MASK, tseg1) |
1217 FIELD_PREP(DBTP_DTSEG2_MASK, tseg2);
1219 m_can_write(cdev, M_CAN_DBTP, reg_btp);
1225 /* Configure M_CAN chip:
1226 * - set rx buffer/fifo element size
1227 * - configure rx fifo
1228 * - accept non-matching frame into fifo 0
1229 * - configure tx buffer
1230 * - >= v3.1.x: TX FIFO is used
1233 * - configure timestamp generation
1235 static void m_can_chip_config(struct net_device *dev)
1237 struct m_can_classdev *cdev = netdev_priv(dev);
1240 m_can_config_endisable(cdev, true);
1242 /* RX Buffer/FIFO Element Size 64 bytes data field */
1243 m_can_write(cdev, M_CAN_RXESC,
1244 FIELD_PREP(RXESC_RBDS_MASK, RXESC_64B) |
1245 FIELD_PREP(RXESC_F1DS_MASK, RXESC_64B) |
1246 FIELD_PREP(RXESC_F0DS_MASK, RXESC_64B));
1248 /* Accept Non-matching Frames Into FIFO 0 */
1249 m_can_write(cdev, M_CAN_GFC, 0x0);
1251 if (cdev->version == 30) {
1252 /* only support one Tx Buffer currently */
1253 m_can_write(cdev, M_CAN_TXBC, FIELD_PREP(TXBC_NDTB_MASK, 1) |
1254 cdev->mcfg[MRAM_TXB].off);
1256 /* TX FIFO is used for newer IP Core versions */
1257 m_can_write(cdev, M_CAN_TXBC,
1258 FIELD_PREP(TXBC_TFQS_MASK,
1259 cdev->mcfg[MRAM_TXB].num) |
1260 cdev->mcfg[MRAM_TXB].off);
1263 /* support 64 bytes payload */
1264 m_can_write(cdev, M_CAN_TXESC,
1265 FIELD_PREP(TXESC_TBDS_MASK, TXESC_TBDS_64B));
1268 if (cdev->version == 30) {
1269 m_can_write(cdev, M_CAN_TXEFC,
1270 FIELD_PREP(TXEFC_EFS_MASK, 1) |
1271 cdev->mcfg[MRAM_TXE].off);
1273 /* Full TX Event FIFO is used */
1274 m_can_write(cdev, M_CAN_TXEFC,
1275 FIELD_PREP(TXEFC_EFS_MASK,
1276 cdev->mcfg[MRAM_TXE].num) |
1277 cdev->mcfg[MRAM_TXE].off);
1280 /* rx fifo configuration, blocking mode, fifo size 1 */
1281 m_can_write(cdev, M_CAN_RXF0C,
1282 FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF0].num) |
1283 cdev->mcfg[MRAM_RXF0].off);
1285 m_can_write(cdev, M_CAN_RXF1C,
1286 FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF1].num) |
1287 cdev->mcfg[MRAM_RXF1].off);
1289 cccr = m_can_read(cdev, M_CAN_CCCR);
1290 test = m_can_read(cdev, M_CAN_TEST);
1292 if (cdev->version == 30) {
1295 cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_DAR |
1296 FIELD_PREP(CCCR_CMR_MASK, FIELD_MAX(CCCR_CMR_MASK)) |
1297 FIELD_PREP(CCCR_CME_MASK, FIELD_MAX(CCCR_CME_MASK)));
1299 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1300 cccr |= FIELD_PREP(CCCR_CME_MASK, CCCR_CME_CANFD_BRS);
1303 /* Version 3.1.x or 3.2.x */
1304 cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
1305 CCCR_NISO | CCCR_DAR);
1307 /* Only 3.2.x has NISO Bit implemented */
1308 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
1311 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1312 cccr |= (CCCR_BRSE | CCCR_FDOE);
1316 if (cdev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
1317 cccr |= CCCR_TEST | CCCR_MON;
1321 /* Enable Monitoring (all versions) */
1322 if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1325 /* Disable Auto Retransmission (all versions) */
1326 if (cdev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
1330 m_can_write(cdev, M_CAN_CCCR, cccr);
1331 m_can_write(cdev, M_CAN_TEST, test);
1333 /* Enable interrupts */
1334 m_can_write(cdev, M_CAN_IR, IR_ALL_INT);
1335 if (!(cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1336 if (cdev->version == 30)
1337 m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
1340 m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
1343 m_can_write(cdev, M_CAN_IE, IR_ALL_INT);
1345 /* route all interrupts to INT0 */
1346 m_can_write(cdev, M_CAN_ILS, ILS_ALL_INT0);
1348 /* set bittiming params */
1349 m_can_set_bittiming(dev);
1351 /* enable internal timestamp generation, with a prescaler of 16. The
1352 * prescaler is applied to the nominal bit timing
1354 m_can_write(cdev, M_CAN_TSCC,
1355 FIELD_PREP(TSCC_TCP_MASK, 0xf) |
1356 FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL));
1358 m_can_config_endisable(cdev, false);
1360 if (cdev->ops->init)
1361 cdev->ops->init(cdev);
1364 static void m_can_start(struct net_device *dev)
1366 struct m_can_classdev *cdev = netdev_priv(dev);
1368 /* basic m_can configuration */
1369 m_can_chip_config(dev);
1371 cdev->can.state = CAN_STATE_ERROR_ACTIVE;
1373 m_can_enable_all_interrupts(cdev);
1376 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
1379 case CAN_MODE_START:
1382 netif_wake_queue(dev);
1391 /* Checks core release number of M_CAN
1392 * returns 0 if an unsupported device is detected
1393 * else it returns the release and step coded as:
1394 * return value = 10 * <release> + 1 * <step>
1396 static int m_can_check_core_release(struct m_can_classdev *cdev)
1403 /* Read Core Release Version and split into version number
1404 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
1406 crel_reg = m_can_read(cdev, M_CAN_CREL);
1407 rel = (u8)FIELD_GET(CREL_REL_MASK, crel_reg);
1408 step = (u8)FIELD_GET(CREL_STEP_MASK, crel_reg);
1411 /* M_CAN v3.x.y: create return value */
1414 /* Unsupported M_CAN version */
1421 /* Selectable Non ISO support only in version 3.2.x
1422 * This function checks if the bit is writable.
1424 static bool m_can_niso_supported(struct m_can_classdev *cdev)
1426 u32 cccr_reg, cccr_poll = 0;
1427 int niso_timeout = -ETIMEDOUT;
1430 m_can_config_endisable(cdev, true);
1431 cccr_reg = m_can_read(cdev, M_CAN_CCCR);
1432 cccr_reg |= CCCR_NISO;
1433 m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1435 for (i = 0; i <= 10; i++) {
1436 cccr_poll = m_can_read(cdev, M_CAN_CCCR);
1437 if (cccr_poll == cccr_reg) {
1446 cccr_reg &= ~(CCCR_NISO);
1447 m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1449 m_can_config_endisable(cdev, false);
1451 /* return false if time out (-ETIMEDOUT), else return true */
1452 return !niso_timeout;
1455 static int m_can_dev_setup(struct m_can_classdev *cdev)
1457 struct net_device *dev = cdev->net;
1458 int m_can_version, err;
1460 m_can_version = m_can_check_core_release(cdev);
1461 /* return if unsupported version */
1462 if (!m_can_version) {
1463 dev_err(cdev->dev, "Unsupported version number: %2d",
1468 if (!cdev->is_peripheral)
1469 netif_napi_add(dev, &cdev->napi,
1470 m_can_poll, NAPI_POLL_WEIGHT);
1472 /* Shared properties of all M_CAN versions */
1473 cdev->version = m_can_version;
1474 cdev->can.do_set_mode = m_can_set_mode;
1475 cdev->can.do_get_berr_counter = m_can_get_berr_counter;
1477 /* Set M_CAN supported operations */
1478 cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1479 CAN_CTRLMODE_LISTENONLY |
1480 CAN_CTRLMODE_BERR_REPORTING |
1482 CAN_CTRLMODE_ONE_SHOT;
1484 /* Set properties depending on M_CAN version */
1485 switch (cdev->version) {
1487 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
1488 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1491 cdev->can.bittiming_const = &m_can_bittiming_const_30X;
1492 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X;
1495 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
1496 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1499 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1500 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1504 /* Support both MCAN version v3.2.x and v3.3.0 */
1505 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1506 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1508 cdev->can.ctrlmode_supported |=
1509 (m_can_niso_supported(cdev) ?
1510 CAN_CTRLMODE_FD_NON_ISO : 0);
1513 dev_err(cdev->dev, "Unsupported version number: %2d",
1518 if (cdev->ops->init)
1519 cdev->ops->init(cdev);
1524 static void m_can_stop(struct net_device *dev)
1526 struct m_can_classdev *cdev = netdev_priv(dev);
1528 /* disable all interrupts */
1529 m_can_disable_all_interrupts(cdev);
1531 /* Set init mode to disengage from the network */
1532 m_can_config_endisable(cdev, true);
1534 /* set the state as STOPPED */
1535 cdev->can.state = CAN_STATE_STOPPED;
1538 static int m_can_close(struct net_device *dev)
1540 struct m_can_classdev *cdev = netdev_priv(dev);
1542 netif_stop_queue(dev);
1544 if (!cdev->is_peripheral)
1545 napi_disable(&cdev->napi);
1548 m_can_clk_stop(cdev);
1549 free_irq(dev->irq, dev);
1551 if (cdev->is_peripheral) {
1552 cdev->tx_skb = NULL;
1553 destroy_workqueue(cdev->tx_wq);
1557 if (cdev->is_peripheral)
1558 can_rx_offload_disable(&cdev->offload);
1562 phy_power_off(cdev->transceiver);
1567 static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
1569 struct m_can_classdev *cdev = netdev_priv(dev);
1570 /*get wrap around for loopback skb index */
1571 unsigned int wrap = cdev->can.echo_skb_max;
1574 /* calculate next index */
1575 next_idx = (++putidx >= wrap ? 0 : putidx);
1577 /* check if occupied */
1578 return !!cdev->can.echo_skb[next_idx];
1581 static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
1583 struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data;
1584 struct net_device *dev = cdev->net;
1585 struct sk_buff *skb = cdev->tx_skb;
1586 struct id_and_dlc fifo_header;
1591 cdev->tx_skb = NULL;
1593 /* Generate ID field for TX buffer Element */
1594 /* Common to all supported M_CAN versions */
1595 if (cf->can_id & CAN_EFF_FLAG) {
1596 fifo_header.id = cf->can_id & CAN_EFF_MASK;
1597 fifo_header.id |= TX_BUF_XTD;
1599 fifo_header.id = ((cf->can_id & CAN_SFF_MASK) << 18);
1602 if (cf->can_id & CAN_RTR_FLAG)
1603 fifo_header.id |= TX_BUF_RTR;
1605 if (cdev->version == 30) {
1606 netif_stop_queue(dev);
1608 fifo_header.dlc = can_fd_len2dlc(cf->len) << 16;
1610 /* Write the frame ID, DLC, and payload to the FIFO element. */
1611 err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_header, 2);
1615 err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA,
1616 cf->data, DIV_ROUND_UP(cf->len, 4));
1620 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1621 cccr = m_can_read(cdev, M_CAN_CCCR);
1622 cccr &= ~CCCR_CMR_MASK;
1623 if (can_is_canfd_skb(skb)) {
1624 if (cf->flags & CANFD_BRS)
1625 cccr |= FIELD_PREP(CCCR_CMR_MASK,
1626 CCCR_CMR_CANFD_BRS);
1628 cccr |= FIELD_PREP(CCCR_CMR_MASK,
1631 cccr |= FIELD_PREP(CCCR_CMR_MASK, CCCR_CMR_CAN);
1633 m_can_write(cdev, M_CAN_CCCR, cccr);
1635 m_can_write(cdev, M_CAN_TXBTIE, 0x1);
1637 can_put_echo_skb(skb, dev, 0, 0);
1639 m_can_write(cdev, M_CAN_TXBAR, 0x1);
1640 /* End of xmit function for version 3.0.x */
1642 /* Transmit routine for version >= v3.1.x */
1644 /* Check if FIFO full */
1645 if (m_can_tx_fifo_full(cdev)) {
1646 /* This shouldn't happen */
1647 netif_stop_queue(dev);
1649 "TX queue active although FIFO is full.");
1651 if (cdev->is_peripheral) {
1653 dev->stats.tx_dropped++;
1654 return NETDEV_TX_OK;
1656 return NETDEV_TX_BUSY;
1660 /* get put index for frame */
1661 putidx = FIELD_GET(TXFQS_TFQPI_MASK,
1662 m_can_read(cdev, M_CAN_TXFQS));
1664 /* Construct DLC Field, with CAN-FD configuration.
1665 * Use the put index of the fifo as the message marker,
1666 * used in the TX interrupt for sending the correct echo frame.
1669 /* get CAN FD configuration of frame */
1671 if (can_is_canfd_skb(skb)) {
1672 fdflags |= TX_BUF_FDF;
1673 if (cf->flags & CANFD_BRS)
1674 fdflags |= TX_BUF_BRS;
1677 fifo_header.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) |
1678 FIELD_PREP(TX_BUF_DLC_MASK, can_fd_len2dlc(cf->len)) |
1679 fdflags | TX_BUF_EFC;
1680 err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, &fifo_header, 2);
1684 err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA,
1685 cf->data, DIV_ROUND_UP(cf->len, 4));
1689 /* Push loopback echo.
1690 * Will be looped back on TX interrupt based on message marker
1692 can_put_echo_skb(skb, dev, putidx, 0);
1694 /* Enable TX FIFO element to start transfer */
1695 m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
1697 /* stop network queue if fifo full */
1698 if (m_can_tx_fifo_full(cdev) ||
1699 m_can_next_echo_skb_occupied(dev, putidx))
1700 netif_stop_queue(dev);
1703 return NETDEV_TX_OK;
1706 netdev_err(dev, "FIFO write returned %d\n", err);
1707 m_can_disable_all_interrupts(cdev);
1708 return NETDEV_TX_BUSY;
1711 static void m_can_tx_work_queue(struct work_struct *ws)
1713 struct m_can_classdev *cdev = container_of(ws, struct m_can_classdev,
1716 m_can_tx_handler(cdev);
1719 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
1720 struct net_device *dev)
1722 struct m_can_classdev *cdev = netdev_priv(dev);
1724 if (can_dropped_invalid_skb(dev, skb))
1725 return NETDEV_TX_OK;
1727 if (cdev->is_peripheral) {
1729 netdev_err(dev, "hard_xmit called while tx busy\n");
1730 return NETDEV_TX_BUSY;
1733 if (cdev->can.state == CAN_STATE_BUS_OFF) {
1736 /* Need to stop the queue to avoid numerous requests
1737 * from being sent. Suggested improvement is to create
1738 * a queueing mechanism that will queue the skbs and
1739 * process them in order.
1742 netif_stop_queue(cdev->net);
1743 queue_work(cdev->tx_wq, &cdev->tx_work);
1747 return m_can_tx_handler(cdev);
1750 return NETDEV_TX_OK;
1753 static int m_can_open(struct net_device *dev)
1755 struct m_can_classdev *cdev = netdev_priv(dev);
1758 err = phy_power_on(cdev->transceiver);
1762 err = m_can_clk_start(cdev);
1764 goto out_phy_power_off;
1766 /* open the can device */
1767 err = open_candev(dev);
1769 netdev_err(dev, "failed to open can device\n");
1770 goto exit_disable_clks;
1773 if (cdev->is_peripheral)
1774 can_rx_offload_enable(&cdev->offload);
1776 /* register interrupt handler */
1777 if (cdev->is_peripheral) {
1778 cdev->tx_skb = NULL;
1779 cdev->tx_wq = alloc_workqueue("mcan_wq",
1780 WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
1786 INIT_WORK(&cdev->tx_work, m_can_tx_work_queue);
1788 err = request_threaded_irq(dev->irq, NULL, m_can_isr,
1792 err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
1797 netdev_err(dev, "failed to request interrupt\n");
1801 /* start the m_can controller */
1804 if (!cdev->is_peripheral)
1805 napi_enable(&cdev->napi);
1807 netif_start_queue(dev);
1812 if (cdev->is_peripheral)
1813 destroy_workqueue(cdev->tx_wq);
1815 if (cdev->is_peripheral)
1816 can_rx_offload_disable(&cdev->offload);
1819 m_can_clk_stop(cdev);
1821 phy_power_off(cdev->transceiver);
1825 static const struct net_device_ops m_can_netdev_ops = {
1826 .ndo_open = m_can_open,
1827 .ndo_stop = m_can_close,
1828 .ndo_start_xmit = m_can_start_xmit,
1829 .ndo_change_mtu = can_change_mtu,
1832 static int register_m_can_dev(struct net_device *dev)
1834 dev->flags |= IFF_ECHO; /* we support local echo */
1835 dev->netdev_ops = &m_can_netdev_ops;
1837 return register_candev(dev);
1840 static void m_can_of_parse_mram(struct m_can_classdev *cdev,
1841 const u32 *mram_config_vals)
1843 cdev->mcfg[MRAM_SIDF].off = mram_config_vals[0];
1844 cdev->mcfg[MRAM_SIDF].num = mram_config_vals[1];
1845 cdev->mcfg[MRAM_XIDF].off = cdev->mcfg[MRAM_SIDF].off +
1846 cdev->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
1847 cdev->mcfg[MRAM_XIDF].num = mram_config_vals[2];
1848 cdev->mcfg[MRAM_RXF0].off = cdev->mcfg[MRAM_XIDF].off +
1849 cdev->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
1850 cdev->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
1851 FIELD_MAX(RXFC_FS_MASK);
1852 cdev->mcfg[MRAM_RXF1].off = cdev->mcfg[MRAM_RXF0].off +
1853 cdev->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
1854 cdev->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
1855 FIELD_MAX(RXFC_FS_MASK);
1856 cdev->mcfg[MRAM_RXB].off = cdev->mcfg[MRAM_RXF1].off +
1857 cdev->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
1858 cdev->mcfg[MRAM_RXB].num = mram_config_vals[5];
1859 cdev->mcfg[MRAM_TXE].off = cdev->mcfg[MRAM_RXB].off +
1860 cdev->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
1861 cdev->mcfg[MRAM_TXE].num = mram_config_vals[6];
1862 cdev->mcfg[MRAM_TXB].off = cdev->mcfg[MRAM_TXE].off +
1863 cdev->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
1864 cdev->mcfg[MRAM_TXB].num = mram_config_vals[7] &
1865 FIELD_MAX(TXBC_NDTB_MASK);
1868 "sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
1869 cdev->mcfg[MRAM_SIDF].off, cdev->mcfg[MRAM_SIDF].num,
1870 cdev->mcfg[MRAM_XIDF].off, cdev->mcfg[MRAM_XIDF].num,
1871 cdev->mcfg[MRAM_RXF0].off, cdev->mcfg[MRAM_RXF0].num,
1872 cdev->mcfg[MRAM_RXF1].off, cdev->mcfg[MRAM_RXF1].num,
1873 cdev->mcfg[MRAM_RXB].off, cdev->mcfg[MRAM_RXB].num,
1874 cdev->mcfg[MRAM_TXE].off, cdev->mcfg[MRAM_TXE].num,
1875 cdev->mcfg[MRAM_TXB].off, cdev->mcfg[MRAM_TXB].num);
1878 int m_can_init_ram(struct m_can_classdev *cdev)
1883 /* initialize the entire Message RAM in use to avoid possible
1884 * ECC/parity checksum errors when reading an uninitialized buffer
1886 start = cdev->mcfg[MRAM_SIDF].off;
1887 end = cdev->mcfg[MRAM_TXB].off +
1888 cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1890 for (i = start; i < end; i += 4) {
1891 err = m_can_fifo_write_no_off(cdev, i, 0x0);
1898 EXPORT_SYMBOL_GPL(m_can_init_ram);
1900 int m_can_class_get_clocks(struct m_can_classdev *cdev)
1904 cdev->hclk = devm_clk_get(cdev->dev, "hclk");
1905 cdev->cclk = devm_clk_get(cdev->dev, "cclk");
1907 if (IS_ERR(cdev->cclk)) {
1908 dev_err(cdev->dev, "no clock found\n");
1914 EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
1916 struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
1919 struct m_can_classdev *class_dev = NULL;
1920 u32 mram_config_vals[MRAM_CFG_LEN];
1921 struct net_device *net_dev;
1925 ret = fwnode_property_read_u32_array(dev_fwnode(dev),
1928 sizeof(mram_config_vals) / 4);
1930 dev_err(dev, "Could not get Message RAM configuration.");
1935 * Defines the total amount of echo buffers for loopback
1937 tx_fifo_size = mram_config_vals[7];
1939 /* allocate the m_can device */
1940 net_dev = alloc_candev(sizeof_priv, tx_fifo_size);
1942 dev_err(dev, "Failed to allocate CAN device");
1946 class_dev = netdev_priv(net_dev);
1947 class_dev->net = net_dev;
1948 class_dev->dev = dev;
1949 SET_NETDEV_DEV(net_dev, dev);
1951 m_can_of_parse_mram(class_dev, mram_config_vals);
1955 EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
1957 void m_can_class_free_dev(struct net_device *net)
1961 EXPORT_SYMBOL_GPL(m_can_class_free_dev);
1963 int m_can_class_register(struct m_can_classdev *cdev)
1967 if (cdev->pm_clock_support) {
1968 ret = m_can_clk_start(cdev);
1973 if (cdev->is_peripheral) {
1974 ret = can_rx_offload_add_manual(cdev->net, &cdev->offload,
1980 ret = m_can_dev_setup(cdev);
1982 goto rx_offload_del;
1984 ret = register_m_can_dev(cdev->net);
1986 dev_err(cdev->dev, "registering %s failed (err=%d)\n",
1987 cdev->net->name, ret);
1988 goto rx_offload_del;
1991 of_can_transceiver(cdev->net);
1993 dev_info(cdev->dev, "%s device registered (irq=%d, version=%d)\n",
1994 KBUILD_MODNAME, cdev->net->irq, cdev->version);
1997 * Stop clocks. They will be reactivated once the M_CAN device is opened
1999 m_can_clk_stop(cdev);
2004 if (cdev->is_peripheral)
2005 can_rx_offload_del(&cdev->offload);
2007 m_can_clk_stop(cdev);
2011 EXPORT_SYMBOL_GPL(m_can_class_register);
2013 void m_can_class_unregister(struct m_can_classdev *cdev)
2015 if (cdev->is_peripheral)
2016 can_rx_offload_del(&cdev->offload);
2017 unregister_candev(cdev->net);
2019 EXPORT_SYMBOL_GPL(m_can_class_unregister);
2021 int m_can_class_suspend(struct device *dev)
2023 struct m_can_classdev *cdev = dev_get_drvdata(dev);
2024 struct net_device *ndev = cdev->net;
2026 if (netif_running(ndev)) {
2027 netif_stop_queue(ndev);
2028 netif_device_detach(ndev);
2030 m_can_clk_stop(cdev);
2033 pinctrl_pm_select_sleep_state(dev);
2035 cdev->can.state = CAN_STATE_SLEEPING;
2039 EXPORT_SYMBOL_GPL(m_can_class_suspend);
2041 int m_can_class_resume(struct device *dev)
2043 struct m_can_classdev *cdev = dev_get_drvdata(dev);
2044 struct net_device *ndev = cdev->net;
2046 pinctrl_pm_select_default_state(dev);
2048 cdev->can.state = CAN_STATE_ERROR_ACTIVE;
2050 if (netif_running(ndev)) {
2053 ret = m_can_clk_start(cdev);
2057 m_can_init_ram(cdev);
2059 netif_device_attach(ndev);
2060 netif_start_queue(ndev);
2065 EXPORT_SYMBOL_GPL(m_can_class_resume);
2067 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
2068 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
2069 MODULE_LICENSE("GPL v2");
2070 MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");