2 * CAN bus driver for Bosch M_CAN controller
4 * Copyright (C) 2014 Freescale Semiconductor, Inc.
5 * Dong Aisheng <b29396@freescale.com>
7 * Bosch M_CAN user manual can be obtained from:
8 * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
9 * mcan_users_manual_v302.pdf
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/if_arp.h>
19 #include <linux/if_ether.h>
20 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/module.h>
25 #include <linux/netdevice.h>
27 #include <linux/of_device.h>
28 #include <linux/pinctrl/consumer.h>
29 #include <linux/platform_device.h>
31 #include <linux/can/dev.h>
34 #define M_CAN_NAPI_WEIGHT 64
36 /* registers definition */
86 /* CC Control Register(CCCR) */
87 #define CCCR_CCE BIT(1)
88 #define CCCR_INIT BIT(0)
90 /* Bit Timing & Prescaler Register (BTP) */
91 #define BTR_BRP_MASK 0x3ff
92 #define BTR_BRP_SHIFT 16
93 #define BTR_TSEG1_SHIFT 8
94 #define BTR_TSEG1_MASK (0x3f << BTR_TSEG1_SHIFT)
95 #define BTR_TSEG2_SHIFT 4
96 #define BTR_TSEG2_MASK (0xf << BTR_TSEG2_SHIFT)
97 #define BTR_SJW_SHIFT 0
98 #define BTR_SJW_MASK 0xf
100 /* Interrupt Register(IR) */
101 #define IR_ALL_INT 0xffffffff
102 #define IR_STE BIT(31)
103 #define IR_FOE BIT(30)
104 #define IR_ACKE BIT(29)
105 #define IR_BE BIT(28)
106 #define IR_CRCE BIT(27)
107 #define IR_WDI BIT(26)
108 #define IR_BO BIT(25)
109 #define IR_EW BIT(24)
110 #define IR_EP BIT(23)
111 #define IR_ELO BIT(22)
112 #define IR_BEU BIT(21)
113 #define IR_BEC BIT(20)
114 #define IR_DRX BIT(19)
115 #define IR_TOO BIT(18)
116 #define IR_MRAF BIT(17)
117 #define IR_TSW BIT(16)
118 #define IR_TEFL BIT(15)
119 #define IR_TEFF BIT(14)
120 #define IR_TEFW BIT(13)
121 #define IR_TEFN BIT(12)
122 #define IR_TFE BIT(11)
123 #define IR_TCF BIT(10)
125 #define IR_HPM BIT(8)
126 #define IR_RF1L BIT(7)
127 #define IR_RF1F BIT(6)
128 #define IR_RF1W BIT(5)
129 #define IR_RF1N BIT(4)
130 #define IR_RF0L BIT(3)
131 #define IR_RF0F BIT(2)
132 #define IR_RF0W BIT(1)
133 #define IR_RF0N BIT(0)
134 #define IR_ERR_ALL (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE | \
135 IR_WDI | IR_BO | IR_EW | IR_EP | IR_ELO | IR_BEU | \
136 IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
139 /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
140 #define RXFC_FWM_OFF 24
141 #define RXFC_FWM_MASK 0x7f
142 #define RXFC_FWM_1 (1 << RXFC_FWM_OFF)
143 #define RXFC_FS_OFF 16
144 #define RXFC_FS_MASK 0x7f
146 /* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
147 #define RXFS_RFL BIT(25)
148 #define RXFS_FF BIT(24)
149 #define RXFS_FPI_OFF 16
150 #define RXFS_FPI_MASK 0x3f0000
151 #define RXFS_FGI_OFF 8
152 #define RXFS_FGI_MASK 0x3f00
153 #define RXFS_FFL_MASK 0x7f
155 /* Tx Buffer Configuration(TXBC) */
156 #define TXBC_NDTB_OFF 16
157 #define TXBC_NDTB_MASK 0x3f
159 /* Tx Buffer Element Size Configuration(TXESC) */
160 #define TXESC_TBDS_8BYTES 0x0
161 /* Tx Buffer Element */
162 #define TX_BUF_XTD BIT(30)
163 #define TX_BUF_RTR BIT(29)
165 /* Rx Buffer Element Size Configuration(TXESC) */
166 #define M_CAN_RXESC_8BYTES 0x0
167 /* Tx Buffer Element */
168 #define RX_BUF_ESI BIT(31)
169 #define RX_BUF_XTD BIT(30)
170 #define RX_BUF_RTR BIT(29)
172 /* Message RAM Configuration (in bytes) */
173 #define SIDF_ELEMENT_SIZE 4
174 #define XIDF_ELEMENT_SIZE 8
175 #define RXF0_ELEMENT_SIZE 16
176 #define RXF1_ELEMENT_SIZE 16
177 #define RXB_ELEMENT_SIZE 16
178 #define TXE_ELEMENT_SIZE 8
179 #define TXB_ELEMENT_SIZE 16
181 /* m_can private data structure */
183 struct can_priv can; /* must be the first member */
184 struct napi_struct napi;
185 struct net_device *dev;
186 struct device *device;
191 /* message ram configuration */
192 void __iomem *mram_base;
210 static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
212 return readl(priv->base + reg);
215 static inline void m_can_write(const struct m_can_priv *priv,
216 enum m_can_reg reg, u32 val)
218 writel(val, priv->base + reg);
221 static inline void m_can_config_endisable(const struct m_can_priv *priv,
224 u32 cccr = m_can_read(priv, M_CAN_CCCR);
225 u32 timeout = 10, val;
228 /* enable m_can configuration */
229 m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
230 /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
231 m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
233 m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
236 /* there's a delay for module initialization */
237 val = enable ? CCCR_INIT | CCCR_CCE : 0;
238 while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE))
241 netdev_warn(priv->dev, "Failed to init module\n");
249 static void m_can_enable_all_interrupts(struct m_can_priv *priv, bool enable)
251 m_can_write(priv, M_CAN_ILE, enable ? 0x00000003 : 0x0);
254 static int m_can_do_rx_poll(struct net_device *dev, int quota)
256 struct m_can_priv *priv = netdev_priv(dev);
257 struct net_device_stats *stats = &dev->stats;
259 struct can_frame *frame;
260 u32 rxfs, flags, fgi;
263 rxfs = m_can_read(priv, M_CAN_RXF0S);
264 if (!(rxfs & RXFS_FFL_MASK)) {
265 netdev_dbg(dev, "no messages in fifo0\n");
269 while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
270 netdev_dbg(dev, "fifo0 status 0x%x\n", rxfs);
272 netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
274 skb = alloc_can_skb(dev, &frame);
280 fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
281 flags = readl(priv->mram_base + priv->rxf0_off + fgi * 16);
282 if (flags & RX_BUF_XTD)
283 frame->can_id = (flags & CAN_EFF_MASK) | CAN_EFF_FLAG;
285 frame->can_id = (flags >> 18) & CAN_SFF_MASK;
286 netdev_dbg(dev, "R0 0x%x\n", flags);
288 if (flags & RX_BUF_RTR) {
289 frame->can_id |= CAN_RTR_FLAG;
291 flags = readl(priv->mram_base +
292 priv->rxf0_off + fgi * 16 + 0x4);
293 frame->can_dlc = get_can_dlc((flags >> 16) & 0x0F);
294 netdev_dbg(dev, "R1 0x%x\n", flags);
296 *(u32 *)(frame->data + 0) = readl(priv->mram_base +
297 priv->rxf0_off + fgi * 16 + 0x8);
298 *(u32 *)(frame->data + 4) = readl(priv->mram_base +
299 priv->rxf0_off + fgi * 16 + 0xC);
300 netdev_dbg(dev, "R2 0x%x\n", *(u32 *)(frame->data + 0));
301 netdev_dbg(dev, "R3 0x%x\n", *(u32 *)(frame->data + 4));
304 /* acknowledge rx fifo 0 */
305 m_can_write(priv, M_CAN_RXF0A, fgi);
307 netif_receive_skb(skb);
308 netdev_dbg(dev, "new packet received\n");
311 stats->rx_bytes += frame->can_dlc;
313 can_led_event(dev, CAN_LED_EVENT_RX);
317 rxfs = m_can_read(priv, M_CAN_RXF0S);
323 static int m_can_poll(struct napi_struct *napi, int quota)
325 struct net_device *dev = napi->dev;
326 struct m_can_priv *priv = netdev_priv(dev);
330 irqstatus = m_can_read(priv, M_CAN_IR);
332 netdev_dbg(dev, "irqstatus updated! new 0x%x old 0x%x rxf0s 0x%x\n",
333 irqstatus, priv->irqstatus,
334 m_can_read(priv, M_CAN_RXF0S));
336 irqstatus = irqstatus | priv->irqstatus;
340 if (irqstatus & IR_RF0N)
341 /* handle events corresponding to receive message objects */
342 work_done += m_can_do_rx_poll(dev, (quota - work_done));
344 if (work_done < quota) {
346 /* enable all IRQs */
347 m_can_enable_all_interrupts(priv, true);
354 static irqreturn_t m_can_isr(int irq, void *dev_id)
356 struct net_device *dev = (struct net_device *)dev_id;
357 struct m_can_priv *priv = netdev_priv(dev);
358 struct net_device_stats *stats = &dev->stats;
361 ir = m_can_read(priv, M_CAN_IR);
365 netdev_dbg(dev, "ir 0x%x rxfs0 0x%x\n", ir,
366 m_can_read(priv, M_CAN_RXF0S));
370 m_can_write(priv, M_CAN_IR, ir);
372 if (ir & IR_ERR_ALL) {
373 netdev_dbg(dev, "bus error\n");
374 /* TODO: handle bus error */
377 /* save irqstatus for later using */
378 priv->irqstatus = ir;
381 * schedule NAPI in case of
383 * - state change IRQ(TODO)
384 * - bus error IRQ and bus error reporting (TODO)
387 m_can_enable_all_interrupts(priv, false);
388 napi_schedule(&priv->napi);
393 dev->stats.rx_over_errors++;
394 dev->stats.rx_errors++;
397 /* transmission complete interrupt */
399 netdev_dbg(dev, "tx complete\n");
400 stats->tx_bytes += can_get_echo_skb(dev, 0);
402 can_led_event(dev, CAN_LED_EVENT_TX);
403 netif_wake_queue(dev);
409 static const struct can_bittiming_const m_can_bittiming_const = {
410 .name = KBUILD_MODNAME,
411 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
413 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
421 static int m_can_set_bittiming(struct net_device *dev)
423 struct m_can_priv *priv = netdev_priv(dev);
424 const struct can_bittiming *bt = &priv->can.bittiming;
425 u16 brp, sjw, tseg1, tseg2;
430 tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
431 tseg2 = bt->phase_seg2 - 1;
432 reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) |
433 (tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT);
434 m_can_write(priv, M_CAN_BTP, reg_btp);
435 netdev_dbg(dev, "setting BTP 0x%x\n", reg_btp);
441 * Configure M_CAN chip:
442 * - set rx buffer/fifo element size
443 * - configure rx fifo
444 * - accept non-matching frame into fifo 0
445 * - configure tx buffer
448 * 1) other working modes support like monitor, loopback...
449 * 2) lec error status report enable
451 static void m_can_chip_config(struct net_device *dev)
453 struct m_can_priv *priv = netdev_priv(dev);
455 m_can_config_endisable(priv, true);
457 /* RX Buffer/FIFO Element Size 8 bytes data field */
458 m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_8BYTES);
460 /* Accept Non-matching Frames Into FIFO 0 */
461 m_can_write(priv, M_CAN_GFC, 0x0);
463 /* only support one Tx Buffer currently */
464 m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) |
465 (priv->mram_off + priv->txb_off));
467 /* only support 8 bytes firstly */
468 m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES);
470 m_can_write(priv, M_CAN_TXEFC, 0x00010000 |
471 (priv->mram_off + priv->txe_off));
473 /* rx fifo configuration, blocking mode, fifo size 1 */
474 m_can_write(priv, M_CAN_RXF0C, (priv->rxf0_elems << RXFC_FS_OFF) |
475 RXFC_FWM_1 | (priv->mram_off + priv->rxf0_off));
477 m_can_write(priv, M_CAN_RXF1C, (priv->rxf1_elems << RXFC_FS_OFF) |
478 RXFC_FWM_1 | (priv->mram_off + priv->rxf1_off));
480 /* enable all interrupts */
481 m_can_write(priv, M_CAN_IR, IR_ALL_INT);
482 m_can_write(priv, M_CAN_IE, IR_ALL_INT);
483 m_can_write(priv, M_CAN_ILS, 0xFFFF0000);
485 /* set bittiming params */
486 m_can_set_bittiming(dev);
488 m_can_config_endisable(priv, false);
491 static void m_can_start(struct net_device *dev)
493 struct m_can_priv *priv = netdev_priv(dev);
495 /* basic m_can configuration */
496 m_can_chip_config(dev);
498 priv->can.state = CAN_STATE_ERROR_ACTIVE;
500 /* enable status change, error and module interrupts */
501 m_can_enable_all_interrupts(priv, true);
504 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
509 netif_wake_queue(dev);
518 static int m_can_get_berr_counter(const struct net_device *dev,
519 struct can_berr_counter *bec)
526 static void free_m_can_dev(struct net_device *dev)
531 static struct net_device *alloc_m_can_dev(void)
533 struct net_device *dev;
534 struct m_can_priv *priv;
536 dev = alloc_candev(sizeof(struct m_can_priv), 1);
540 priv = netdev_priv(dev);
541 netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
544 priv->can.bittiming_const = &m_can_bittiming_const;
545 priv->can.do_set_mode = m_can_set_mode;
546 priv->can.do_get_berr_counter = m_can_get_berr_counter;
547 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
548 CAN_CTRLMODE_LISTENONLY |
549 CAN_CTRLMODE_BERR_REPORTING;
555 static int m_can_open(struct net_device *dev)
558 struct m_can_priv *priv = netdev_priv(dev);
560 clk_prepare_enable(priv->clk);
562 /* open the can device */
563 err = open_candev(dev);
565 netdev_err(dev, "failed to open can device\n");
569 /* register interrupt handler */
570 err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
573 netdev_err(dev, "failed to request interrupt\n");
577 /* start the m_can controller */
580 can_led_event(dev, CAN_LED_EVENT_OPEN);
581 napi_enable(&priv->napi);
582 netif_start_queue(dev);
589 clk_disable_unprepare(priv->clk);
593 static void m_can_stop(struct net_device *dev)
595 struct m_can_priv *priv = netdev_priv(dev);
597 /* disable all interrupts */
598 m_can_enable_all_interrupts(priv, false);
600 /* set the state as STOPPED */
601 priv->can.state = CAN_STATE_STOPPED;
605 static int m_can_close(struct net_device *dev)
607 struct m_can_priv *priv = netdev_priv(dev);
609 netif_stop_queue(dev);
610 napi_disable(&priv->napi);
612 free_irq(dev->irq, dev);
614 can_led_event(dev, CAN_LED_EVENT_STOP);
619 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
620 struct net_device *dev)
622 struct m_can_priv *priv = netdev_priv(dev);
623 struct can_frame *frame = (struct can_frame *)skb->data;
626 if (can_dropped_invalid_skb(dev, skb))
629 netif_stop_queue(dev);
631 if (frame->can_id & CAN_RTR_FLAG)
634 if (frame->can_id & CAN_EFF_FLAG) {
635 id = frame->can_id & CAN_EFF_MASK;
638 id = ((frame->can_id & CAN_SFF_MASK) << 18);
641 /* message ram configuration */
643 priv->mram_base + priv->mram_off + priv->txb_off);
644 writel(frame->can_dlc << 16,
645 priv->mram_base + priv->mram_off + priv->txb_off + 0x4);
646 writel(*(u32 *)(frame->data + 0),
647 priv->mram_base + priv->mram_off + priv->txb_off + 0x8);
648 writel(*(u32 *)(frame->data + 4),
649 priv->mram_base + priv->mram_off + priv->txb_off + 0xc);
651 can_put_echo_skb(skb, dev, 0);
653 /* enable first TX buffer to start transfer */
654 m_can_write(priv, M_CAN_TXBTIE, 0x00000001);
655 m_can_write(priv, M_CAN_TXBAR, 0x00000001);
660 static const struct net_device_ops m_can_netdev_ops = {
661 .ndo_open = m_can_open,
662 .ndo_stop = m_can_close,
663 .ndo_start_xmit = m_can_start_xmit,
666 static int register_m_can_dev(struct net_device *dev)
668 dev->flags |= IFF_ECHO; /* we support local echo */
669 dev->netdev_ops = &m_can_netdev_ops;
671 return register_candev(dev);
674 static const struct of_device_id m_can_of_table[] = {
675 { .compatible = "bosch,m_can", .data = NULL },
678 MODULE_DEVICE_TABLE(of, m_can_of_table);
680 static int m_can_of_parse_mram(struct platform_device *pdev,
681 struct m_can_priv *priv)
683 struct device_node *np = pdev->dev.of_node;
684 struct resource *res;
689 /* message ram could be shared */
690 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
694 addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
698 /* get message ram configuration */
699 ret = of_property_read_u32_array(np, "mram-cfg",
700 out_val, sizeof(out_val) / 4);
702 dev_err(&pdev->dev, "can not get message ram configuration\n");
706 priv->mram_base = addr;
707 priv->mram_off = out_val[0];
708 priv->sidf_elems = out_val[1];
709 priv->sidf_off = priv->mram_off;
710 priv->xidf_elems = out_val[2];
711 priv->xidf_off = priv->sidf_off + priv->sidf_elems * SIDF_ELEMENT_SIZE;
712 priv->rxf0_elems = out_val[3] & RXFC_FS_MASK;
713 priv->rxf0_off = priv->xidf_off + priv->xidf_elems * XIDF_ELEMENT_SIZE;
714 priv->rxf1_elems = out_val[4] & RXFC_FS_MASK;
715 priv->rxf1_off = priv->rxf0_off + priv->rxf0_elems * RXF0_ELEMENT_SIZE;
716 priv->rxb_elems = out_val[5];
717 priv->rxb_off = priv->rxf1_off + priv->rxf1_elems * RXF1_ELEMENT_SIZE;
718 priv->txe_elems = out_val[6];
719 priv->txe_off = priv->rxb_off + priv->rxb_elems * RXB_ELEMENT_SIZE;
720 priv->txb_elems = out_val[7] & TXBC_NDTB_MASK;
721 priv->txb_off = priv->txe_off + priv->txe_elems * TXE_ELEMENT_SIZE;
723 dev_dbg(&pdev->dev, "mram_base =%p mram_off =0x%x "
724 "sidf %d xidf %d rxf0 %d rxf1 %d rxb %d txe %d txb %d\n",
725 priv->mram_base, priv->mram_off, priv->sidf_elems,
726 priv->xidf_elems, priv->rxf0_elems, priv->rxf1_elems,
727 priv->rxb_elems, priv->txe_elems, priv->txb_elems);
732 static int m_can_plat_probe(struct platform_device *pdev)
734 struct net_device *dev;
735 struct m_can_priv *priv;
736 struct pinctrl *pinctrl;
737 struct resource *res;
742 pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
745 "failed to configure pins from driver\n");
747 clk = devm_clk_get(&pdev->dev, NULL);
749 dev_err(&pdev->dev, "no clock find\n");
753 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "canfd");
754 addr = devm_request_and_ioremap(&pdev->dev, res);
755 irq = platform_get_irq(pdev, 0);
756 if (!addr || irq < 0)
759 /* allocate the m_can device */
760 dev = alloc_m_can_dev();
764 priv = netdev_priv(dev);
767 priv->device = &pdev->dev;
769 priv->can.clock.freq = clk_get_rate(clk);
771 ret = m_can_of_parse_mram(pdev, priv);
773 goto failed_free_dev;
775 platform_set_drvdata(pdev, dev);
776 SET_NETDEV_DEV(dev, &pdev->dev);
778 ret = register_m_can_dev(dev);
780 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
781 KBUILD_MODNAME, ret);
782 goto failed_free_dev;
785 devm_can_led_init(dev);
787 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
788 KBUILD_MODNAME, priv->base, dev->irq);
798 static int m_can_suspend(struct device *dev)
800 struct net_device *ndev = dev_get_drvdata(dev);
801 struct m_can_priv *priv = netdev_priv(ndev);
803 if (netif_running(ndev)) {
804 netif_stop_queue(ndev);
805 netif_device_detach(ndev);
808 /* TODO: enter low power */
810 priv->can.state = CAN_STATE_SLEEPING;
815 static int m_can_resume(struct device *dev)
817 struct net_device *ndev = dev_get_drvdata(dev);
818 struct m_can_priv *priv = netdev_priv(ndev);
820 /* TODO: exit low power */
822 priv->can.state = CAN_STATE_ERROR_ACTIVE;
824 if (netif_running(ndev)) {
825 netif_device_attach(ndev);
826 netif_start_queue(ndev);
833 static void unregister_m_can_dev(struct net_device *dev)
835 unregister_candev(dev);
838 static int m_can_plat_remove(struct platform_device *pdev)
840 struct net_device *dev = platform_get_drvdata(pdev);
842 unregister_m_can_dev(dev);
843 platform_set_drvdata(pdev, NULL);
850 static const struct dev_pm_ops m_can_pmops = {
851 SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
854 static struct platform_driver m_can_plat_driver = {
856 .name = KBUILD_MODNAME,
857 .owner = THIS_MODULE,
858 .of_match_table = of_match_ptr(m_can_of_table),
861 .probe = m_can_plat_probe,
862 .remove = m_can_plat_remove,
865 module_platform_driver(m_can_plat_driver);
867 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
868 MODULE_LICENSE("GPL v2");
869 MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");