/* * CAN bus driver for Bosch M_CAN controller * * Copyright (C) 2014 Freescale Semiconductor, Inc. * Dong Aisheng * * Bosch M_CAN user manual can be obtained from: * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/ * mcan_users_manual_v302.pdf * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include #include #include #include #include #include #include #include #include #include #include /* napi related */ #define M_CAN_NAPI_WEIGHT 64 /* message ram configuration data length */ #define MRAM_CFG_LEN 8 /* enable Debug */ #define M_CAN_DEBUG_ENABLE 1 /* registers definition */ enum m_can_reg { M_CAN_CREL = 0x0, M_CAN_ENDN = 0x4, M_CAN_CUST = 0x8, M_CAN_FBTP = 0xc, M_CAN_TEST = 0x10, M_CAN_RWD = 0x14, M_CAN_CCCR = 0x18, M_CAN_BTP = 0x1c, M_CAN_TSCC = 0x20, M_CAN_TSCV = 0x24, M_CAN_TOCC = 0x28, M_CAN_TOCV = 0x2c, M_CAN_ECR = 0x40, M_CAN_PSR = 0x44, M_CAN_IR = 0x50, M_CAN_IE = 0x54, M_CAN_ILS = 0x58, M_CAN_ILE = 0x5c, M_CAN_GFC = 0x80, M_CAN_SIDFC = 0x84, M_CAN_XIDFC = 0x88, M_CAN_XIDAM = 0x90, M_CAN_HPMS = 0x94, M_CAN_NDAT1 = 0x98, M_CAN_NDAT2 = 0x9c, M_CAN_RXF0C = 0xa0, M_CAN_RXF0S = 0xa4, M_CAN_RXF0A = 0xa8, M_CAN_RXBC = 0xac, M_CAN_RXF1C = 0xb0, M_CAN_RXF1S = 0xb4, M_CAN_RXF1A = 0xb8, M_CAN_RXESC = 0xbc, M_CAN_TXBC = 0xc0, M_CAN_TXFQS = 0xc4, M_CAN_TXESC = 0xc8, M_CAN_TXBRP = 0xcc, M_CAN_TXBAR = 0xd0, M_CAN_TXBCR = 0xd4, M_CAN_TXBTO = 0xd8, M_CAN_TXBCF = 0xdc, M_CAN_TXBTIE = 0xe0, M_CAN_TXBCIE = 0xe4, M_CAN_TXEFC = 0xf0, M_CAN_TXEFS = 0xf4, M_CAN_TXEFA = 0xf8, }; /* m_can lec values */ enum m_can_lec_type { LEC_NO_ERROR = 0, LEC_STUFF_ERROR, LEC_FORM_ERROR, LEC_ACK_ERROR, LEC_BIT1_ERROR, LEC_BIT0_ERROR, LEC_CRC_ERROR, LEC_UNUSED, }; enum m_can_mram_cfg { MRAM_SIDF = 0, MRAM_XIDF, MRAM_RXF0, MRAM_RXF1, MRAM_RXB, MRAM_TXE, MRAM_TXB, MRAM_CFG_NUM, }; /* Fast Bit Timing & Prescaler Register (FBTP) */ #define FBTR_FBRP_MASK 0x1f #define FBTR_FBRP_SHIFT 16 #define FBTR_FTSEG1_SHIFT 8 #define FBTR_FTSEG1_MASK (0xf << FBTR_FTSEG1_SHIFT) #define FBTR_FTSEG2_SHIFT 4 #define FBTR_FTSEG2_MASK (0x7 << FBTR_FTSEG2_SHIFT) #define FBTR_FSJW_SHIFT 0 #define FBTR_FSJW_MASK 0x3 /* Test Register (TEST) */ #define TEST_LBCK BIT(4) /* CC Control Register(CCCR) */ #define CCCR_TEST BIT(7) #define CCCR_CMR_MASK 0x3 #define CCCR_CMR_SHIFT 10 #define CCCR_CMR_CANFD 0x1 #define CCCR_CMR_CANFD_BRS 0x2 #define CCCR_CMR_CAN 0x3 #define CCCR_CME_MASK 0x3 #define CCCR_CME_SHIFT 8 #define CCCR_CME_CAN 0 #define CCCR_CME_CANFD 0x1 #define CCCR_CME_CANFD_BRS 0x2 #define CCCR_TEST BIT(7) #define CCCR_MON BIT(5) #define CCCR_CCE BIT(1) #define CCCR_INIT BIT(0) #define CCCR_CANFD 0x10 /* Bit Timing & Prescaler Register (BTP) */ #define BTR_BRP_MASK 0x3ff #define BTR_BRP_SHIFT 16 #define BTR_TSEG1_SHIFT 8 #define BTR_TSEG1_MASK (0x3f << BTR_TSEG1_SHIFT) #define BTR_TSEG2_SHIFT 4 #define BTR_TSEG2_MASK (0xf << BTR_TSEG2_SHIFT) #define BTR_SJW_SHIFT 0 #define BTR_SJW_MASK 0xf /* Error Counter Register(ECR) */ #define ECR_RP BIT(15) #define ECR_REC_SHIFT 8 #define ECR_REC_MASK (0x7f << ECR_REC_SHIFT) #define ECR_TEC_SHIFT 0 #define ECR_TEC_MASK 0xff /* Protocol Status Register(PSR) */ #define PSR_BO BIT(7) #define PSR_EW BIT(6) #define PSR_EP BIT(5) #define PSR_LEC_MASK 0x7 /* Interrupt Register(IR) */ #define IR_ALL_INT 0xffffffff #define IR_STE BIT(31) #define IR_FOE BIT(30) #define IR_ACKE BIT(29) #define IR_BE BIT(28) #define IR_CRCE BIT(27) #define IR_WDI BIT(26) #define IR_BO BIT(25) #define IR_EW BIT(24) #define IR_EP BIT(23) #define IR_ELO BIT(22) #define IR_BEU BIT(21) #define IR_BEC BIT(20) #define IR_DRX BIT(19) #define IR_TOO BIT(18) #define IR_MRAF BIT(17) #define IR_TSW BIT(16) #define IR_TEFL BIT(15) #define IR_TEFF BIT(14) #define IR_TEFW BIT(13) #define IR_TEFN BIT(12) #define IR_TFE BIT(11) #define IR_TCF BIT(10) #define IR_TC BIT(9) #define IR_HPM BIT(8) #define IR_RF1L BIT(7) #define IR_RF1F BIT(6) #define IR_RF1W BIT(5) #define IR_RF1N BIT(4) #define IR_RF0L BIT(3) #define IR_RF0F BIT(2) #define IR_RF0W BIT(1) #define IR_RF0N BIT(0) #define IR_ERR_STATE (IR_BO | IR_EW | IR_EP) #define IR_ERR_LEC (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE) #define IR_ERR_BUS (IR_ERR_LEC | IR_WDI | IR_ELO | IR_BEU | \ IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \ IR_RF1L | IR_RF0L) #define IR_ERR_ALL (IR_ERR_STATE | IR_ERR_BUS) /* Interrupt Line Select (ILS) */ #define ILS_ALL_INT0 0x0 #define ILS_ALL_INT1 0xFFFFFFFF /* Interrupt Line Enable (ILE) */ #define ILE_EINT0 BIT(0) #define ILE_EINT1 BIT(1) /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */ #define RXFC_FWM_OFF 24 #define RXFC_FWM_MASK 0x7f #define RXFC_FWM_1 (1 << RXFC_FWM_OFF) #define RXFC_FS_OFF 16 #define RXFC_FS_MASK 0x7f /* Rx FIFO 0/1 Status (RXF0S/RXF1S) */ #define RXFS_RFL BIT(25) #define RXFS_FF BIT(24) #define RXFS_FPI_OFF 16 #define RXFS_FPI_MASK 0x3f0000 #define RXFS_FGI_OFF 8 #define RXFS_FGI_MASK 0x3f00 #define RXFS_FFL_MASK 0x7f /* Rx Buffer / FIFO Element Size Configuration (RXESC) */ #define M_CAN_RXESC_8BYTES 0x0 #define M_CAN_RXESC_64BYTES 0x777 /* Tx Buffer Configuration(TXBC) */ #define TXBC_NDTB_OFF 16 #define TXBC_NDTB_MASK 0x3f /* Tx Buffer Element Size Configuration(TXESC) */ #define TXESC_TBDS_8BYTES 0x0 #define TXESC_TBDS_64BYTES 0x7 /* Tx Event FIFO Con.guration (TXEFC) */ #define TXEFC_EFS_OFF 16 #define TXEFC_EFS_MASK 0x3f /* Message RAM Configuration (in bytes) */ #define SIDF_ELEMENT_SIZE 4 #define XIDF_ELEMENT_SIZE 8 #define RXF0_ELEMENT_SIZE 72 #define RXF1_ELEMENT_SIZE 72 #define RXB_ELEMENT_SIZE 16 #define TXE_ELEMENT_SIZE 8 #define TXB_ELEMENT_SIZE 72 /* Message RAM Elements */ #define M_CAN_FIFO_ID 0x0 #define M_CAN_FIFO_DLC 0x4 #define M_CAN_FIFO_DATA(n) (0x8 + ((n) << 2)) /* Rx Buffer Element */ /* R0 */ #define RX_BUF_ESI BIT(31) #define RX_BUF_XTD BIT(30) #define RX_BUF_RTR BIT(29) /* R1 */ #define RX_BUF_ANMF BIT(31) #define RX_BUF_EDL BIT(21) #define RX_BUF_BRS BIT(20) /* Tx Buffer Element */ /* R0 */ #define TX_BUF_XTD BIT(30) #define TX_BUF_RTR BIT(29) /* address offset and element number for each FIFO/Buffer in the Message RAM */ struct mram_cfg { u16 off; u8 num; }; /* m_can private data structure */ struct m_can_priv { struct can_priv can; /* must be the first member */ struct napi_struct napi; struct net_device *dev; struct device *device; struct clk *hclk; struct clk *cclk; void __iomem *base; u32 irqstatus; /* message ram configuration */ void __iomem *mram_base; struct mram_cfg mcfg[MRAM_CFG_NUM]; }; /* debugging function */ static void m_can_debug(const char* format, ...) { #ifdef M_CAN_DEBUG_ENABLE va_list args; va_start(args, format); vprintk(format, args); va_end(args); #endif } static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg) { return readl(priv->base + reg); } static inline void m_can_write(const struct m_can_priv *priv, enum m_can_reg reg, u32 val) { writel(val, priv->base + reg); } static inline u32 m_can_fifo_read(const struct m_can_priv *priv, u32 fgi, unsigned int offset) { return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE + offset); } static inline void m_can_fifo_write(const struct m_can_priv *priv, u32 fpi, unsigned int offset, u32 val) { writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE + offset); } static inline void m_can_config_endisable(const struct m_can_priv *priv, bool enable) { u32 cccr = m_can_read(priv, M_CAN_CCCR); u32 timeout = 10; u32 val = 0; if (enable) { /* enable m_can configuration */ m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT); udelay(5); /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */ m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE); } else { m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE)); } /* there's a delay for module initialization */ if (enable) val = CCCR_INIT | CCCR_CCE; while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) { if (timeout == 0) { netdev_warn(priv->dev, "Failed to init module\n"); return; } timeout--; udelay(1); } } static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv) { m_can_write(priv, M_CAN_ILE, ILE_EINT0 | ILE_EINT1); } static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv) { m_can_write(priv, M_CAN_ILE, 0x0); } static void m_can_read_fifo(struct net_device *dev, u32 rxfs) { struct net_device_stats *stats = &dev->stats; struct m_can_priv *priv = netdev_priv(dev); struct canfd_frame *cf; struct sk_buff *skb; u32 id, fgi, dlc; int i; /* calculate the fifo get index for where to read data */ fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF; dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC); if (dlc & RX_BUF_EDL) skb = alloc_canfd_skb(dev, &cf); else skb = alloc_can_skb(dev, (struct can_frame **)&cf); if (!skb) { stats->rx_dropped++; return; } if (dlc & RX_BUF_EDL) cf->len = can_dlc2len((dlc >> 16) & 0x0F); else cf->len = get_can_dlc((dlc >> 16) & 0x0F); id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID); if (id & RX_BUF_XTD) cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG; else cf->can_id = (id >> 18) & CAN_SFF_MASK; if (id & RX_BUF_ESI) { cf->flags |= CANFD_ESI; netdev_dbg(dev, "ESI Error\n"); } if (!(dlc & RX_BUF_EDL) && (id & RX_BUF_RTR)) { cf->can_id |= CAN_RTR_FLAG; } else { if (dlc & RX_BUF_BRS) cf->flags |= CANFD_BRS; for (i = 0; i < cf->len; i += 4) *(u32 *)(cf->data + i) = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DATA(i / 4)); } /* acknowledge rx fifo 0 */ m_can_write(priv, M_CAN_RXF0A, fgi); stats->rx_packets++; stats->rx_bytes += cf->len; netif_receive_skb(skb); } static int m_can_do_rx_poll(struct net_device *dev, int quota) { struct m_can_priv *priv = netdev_priv(dev); u32 pkts = 0; u32 rxfs; rxfs = m_can_read(priv, M_CAN_RXF0S); if (!(rxfs & RXFS_FFL_MASK)) { netdev_dbg(dev, "no messages in fifo0\n"); return 0; } while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) { if (rxfs & RXFS_RFL) netdev_warn(dev, "Rx FIFO 0 Message Lost\n"); m_can_read_fifo(dev, rxfs); quota--; pkts++; rxfs = m_can_read(priv, M_CAN_RXF0S); } if (pkts) can_led_event(dev, CAN_LED_EVENT_RX); return pkts; } static int m_can_handle_lost_msg(struct net_device *dev) { struct net_device_stats *stats = &dev->stats; struct sk_buff *skb; struct can_frame *frame; netdev_err(dev, "msg lost in rxf0\n"); stats->rx_errors++; stats->rx_over_errors++; skb = alloc_can_err_skb(dev, &frame); if (unlikely(!skb)) return 0; frame->can_id |= CAN_ERR_CRTL; frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; netif_receive_skb(skb); return 1; } static int m_can_handle_lec_err(struct net_device *dev, enum m_can_lec_type lec_type) { struct m_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; priv->can.can_stats.bus_error++; stats->rx_errors++; /* propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(dev, &cf); if (unlikely(!skb)) return 0; /* check for 'last error code' which tells us the * type of the last error to occur on the CAN bus */ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; switch (lec_type) { case LEC_STUFF_ERROR: netdev_dbg(dev, "stuff error\n"); cf->data[2] |= CAN_ERR_PROT_STUFF; break; case LEC_FORM_ERROR: netdev_dbg(dev, "form error\n"); cf->data[2] |= CAN_ERR_PROT_FORM; break; case LEC_ACK_ERROR: netdev_dbg(dev, "ack error\n"); cf->data[3] = CAN_ERR_PROT_LOC_ACK; break; case LEC_BIT1_ERROR: netdev_dbg(dev, "bit1 error\n"); cf->data[2] |= CAN_ERR_PROT_BIT1; break; case LEC_BIT0_ERROR: netdev_dbg(dev, "bit0 error\n"); cf->data[2] |= CAN_ERR_PROT_BIT0; break; case LEC_CRC_ERROR: netdev_dbg(dev, "CRC error\n"); cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; break; default: break; } stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_receive_skb(skb); return 1; } static int __m_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct m_can_priv *priv = netdev_priv(dev); unsigned int ecr; ecr = m_can_read(priv, M_CAN_ECR); bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT; bec->txerr = ecr & ECR_TEC_MASK; return 0; } static int m_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct m_can_priv *priv = netdev_priv(dev); int err; err = clk_prepare_enable(priv->hclk); if (err) return err; err = clk_prepare_enable(priv->cclk); if (err) { clk_disable_unprepare(priv->hclk); return err; } __m_can_get_berr_counter(dev, bec); clk_disable_unprepare(priv->cclk); clk_disable_unprepare(priv->hclk); return 0; } static int m_can_handle_state_change(struct net_device *dev, enum can_state new_state) { struct m_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; struct can_berr_counter bec; unsigned int ecr; switch (new_state) { case CAN_STATE_ERROR_ACTIVE: /* error warning state */ priv->can.can_stats.error_warning++; priv->can.state = CAN_STATE_ERROR_WARNING; break; case CAN_STATE_ERROR_PASSIVE: /* error passive state */ priv->can.can_stats.error_passive++; priv->can.state = CAN_STATE_ERROR_PASSIVE; break; case CAN_STATE_BUS_OFF: /* bus-off state */ priv->can.state = CAN_STATE_BUS_OFF; m_can_disable_all_interrupts(priv); priv->can.can_stats.bus_off++; can_bus_off(dev); break; default: break; } /* propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(dev, &cf); if (unlikely(!skb)) return 0; __m_can_get_berr_counter(dev, &bec); switch (new_state) { case CAN_STATE_ERROR_ACTIVE: /* error warning state */ cf->can_id |= CAN_ERR_CRTL; cf->data[1] = (bec.txerr > bec.rxerr) ? CAN_ERR_CRTL_TX_WARNING : CAN_ERR_CRTL_RX_WARNING; cf->data[6] = bec.txerr; cf->data[7] = bec.rxerr; break; case CAN_STATE_ERROR_PASSIVE: /* error passive state */ cf->can_id |= CAN_ERR_CRTL; ecr = m_can_read(priv, M_CAN_ECR); if (ecr & ECR_RP) cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; if (bec.txerr > 127) cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; cf->data[6] = bec.txerr; cf->data[7] = bec.rxerr; break; case CAN_STATE_BUS_OFF: /* bus-off state */ cf->can_id |= CAN_ERR_BUSOFF; break; default: break; } stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_receive_skb(skb); return 1; } static int m_can_handle_state_errors(struct net_device *dev, u32 psr) { struct m_can_priv *priv = netdev_priv(dev); int work_done = 0; if ((psr & PSR_EW) && (priv->can.state != CAN_STATE_ERROR_WARNING)) { netdev_dbg(dev, "entered error warning state\n"); work_done += m_can_handle_state_change(dev, CAN_STATE_ERROR_WARNING); } if ((psr & PSR_EP) && (priv->can.state != CAN_STATE_ERROR_PASSIVE)) { netdev_dbg(dev, "entered error passive state\n"); work_done += m_can_handle_state_change(dev, CAN_STATE_ERROR_PASSIVE); } if ((psr & PSR_BO) && (priv->can.state != CAN_STATE_BUS_OFF)) { netdev_dbg(dev, "entered error bus off state\n"); work_done += m_can_handle_state_change(dev, CAN_STATE_BUS_OFF); } return work_done; } static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus) { if (irqstatus & IR_WDI) netdev_err(dev, "Message RAM Watchdog event due to missing READY\n"); if (irqstatus & IR_ELO) netdev_err(dev, "Error Logging Overflow\n"); if (irqstatus & IR_BEU) netdev_err(dev, "Bit Error Uncorrected\n"); if (irqstatus & IR_BEC) netdev_err(dev, "Bit Error Corrected\n"); if (irqstatus & IR_TOO) netdev_err(dev, "Timeout reached\n"); if (irqstatus & IR_MRAF) netdev_err(dev, "Message RAM access failure occurred\n"); } static inline bool is_lec_err(u32 psr) { psr &= LEC_UNUSED; return psr && (psr != LEC_UNUSED); } static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus, u32 psr) { struct m_can_priv *priv = netdev_priv(dev); int work_done = 0; if (irqstatus & IR_RF0L) work_done += m_can_handle_lost_msg(dev); /* handle lec errors on the bus */ if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) && is_lec_err(psr)) work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED); /* other unproccessed error interrupts */ m_can_handle_other_err(dev, irqstatus); return work_done; } static int m_can_poll(struct napi_struct *napi, int quota) { struct net_device *dev = napi->dev; struct m_can_priv *priv = netdev_priv(dev); int work_done = 0; u32 irqstatus, psr; irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR); if (!irqstatus) goto end; psr = m_can_read(priv, M_CAN_PSR); if (irqstatus & IR_ERR_STATE) work_done += m_can_handle_state_errors(dev, psr); if (irqstatus & IR_ERR_BUS) work_done += m_can_handle_bus_errors(dev, irqstatus, psr); if (irqstatus & IR_RF0N) work_done += m_can_do_rx_poll(dev, (quota - work_done)); if (work_done < quota) { napi_complete(napi); m_can_enable_all_interrupts(priv); } end: return work_done; } static irqreturn_t m_can_isr(int irq, void *dev_id) { struct net_device *dev = (struct net_device *)dev_id; struct m_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; u32 ir; ir = m_can_read(priv, M_CAN_IR); if (!ir) return IRQ_NONE; /* ACK all irqs */ if (ir & IR_ALL_INT) m_can_write(priv, M_CAN_IR, ir); /* schedule NAPI in case of * - rx IRQ * - state change IRQ * - bus error IRQ and bus error reporting */ if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) { priv->irqstatus = ir; m_can_disable_all_interrupts(priv); napi_schedule(&priv->napi); } /* transmission complete interrupt */ if (ir & IR_TC) { stats->tx_bytes += can_get_echo_skb(dev, 0); stats->tx_packets++; can_led_event(dev, CAN_LED_EVENT_TX); netif_wake_queue(dev); } return IRQ_HANDLED; } static const struct can_bittiming_const m_can_bittiming_const = { .name = KBUILD_MODNAME, .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ .tseg1_max = 64, .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ .tseg2_max = 16, .sjw_max = 16, .brp_min = 1, .brp_max = 1024, .brp_inc = 1, }; static const struct can_bittiming_const m_can_data_bittiming_const = { .name = KBUILD_MODNAME, .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ .tseg1_max = 16, .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ .tseg2_max = 8, .sjw_max = 4, .brp_min = 1, .brp_max = 32, .brp_inc = 1, }; static int m_can_set_bittiming(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); const struct can_bittiming *bt = &priv->can.bittiming; const struct can_bittiming *dbt = &priv->can.data_bittiming; u16 brp, sjw, tseg1, tseg2; u32 reg_btp; brp = bt->brp - 1; sjw = bt->sjw - 1; tseg1 = bt->prop_seg + bt->phase_seg1 - 1; tseg2 = bt->phase_seg2 - 1; reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) | (tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT); m_can_write(priv, M_CAN_BTP, reg_btp); if (priv->can.ctrlmode & CAN_CTRLMODE_FD) { brp = dbt->brp - 1; sjw = dbt->sjw - 1; tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1; tseg2 = dbt->phase_seg2 - 1; reg_btp = (brp << FBTR_FBRP_SHIFT) | (sjw << FBTR_FSJW_SHIFT) | (tseg1 << FBTR_FTSEG1_SHIFT) | (tseg2 << FBTR_FTSEG2_SHIFT); m_can_write(priv, M_CAN_FBTP, reg_btp); } return 0; } /* Configure M_CAN chip: * - set rx buffer/fifo element size * - configure rx fifo * - accept non-matching frame into fifo 0 * - configure tx buffer * - configure mode * - setup bittiming */ static void m_can_chip_config(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); u32 cccr, test; m_can_config_endisable(priv, true); /* RX Buffer/FIFO Element Size 64 bytes data field */ m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES); /* Accept Non-matching Frames Into FIFO 0 */ m_can_write(priv, M_CAN_GFC, 0x0); /* only support one Tx Buffer currently */ m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) | priv->mcfg[MRAM_TXB].off); /* support 64 bytes payload */ m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES); m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) | priv->mcfg[MRAM_TXE].off); /* rx fifo configuration, blocking mode, fifo size 1 */ m_can_write(priv, M_CAN_RXF0C, (priv->mcfg[MRAM_RXF0].num << RXFC_FS_OFF) | RXFC_FWM_1 | priv->mcfg[MRAM_RXF0].off); m_can_write(priv, M_CAN_RXF1C, (priv->mcfg[MRAM_RXF1].num << RXFC_FS_OFF) | RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off); cccr = m_can_read(priv, M_CAN_CCCR); cccr &= ~(CCCR_TEST | CCCR_MON | (CCCR_CMR_MASK << CCCR_CMR_SHIFT) | (CCCR_CME_MASK << CCCR_CME_SHIFT)); test = m_can_read(priv, M_CAN_TEST); test &= ~TEST_LBCK; if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) cccr |= CCCR_MON; if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { cccr |= CCCR_TEST; test |= TEST_LBCK; } // TODO: Check if (priv->can.ctrlmode & CAN_CTRLMODE_FD) cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT; m_can_write(priv, M_CAN_CCCR, cccr); m_can_write(priv, M_CAN_TEST, test); /* enable interrupts */ m_can_write(priv, M_CAN_IR, IR_ALL_INT); if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) m_can_write(priv, M_CAN_IE, IR_ALL_INT & ~IR_ERR_LEC); else m_can_write(priv, M_CAN_IE, IR_ALL_INT); /* route all interrupts to INT0 */ m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0); /* set bittiming params */ m_can_set_bittiming(dev); m_can_config_endisable(priv, false); } static void m_can_start(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); /* basic m_can configuration */ m_can_chip_config(dev); priv->can.state = CAN_STATE_ERROR_ACTIVE; m_can_enable_all_interrupts(priv); } static int m_can_set_mode(struct net_device *dev, enum can_mode mode) { switch (mode) { case CAN_MODE_START: m_can_start(dev); netif_wake_queue(dev); break; default: return -EOPNOTSUPP; } return 0; } static void free_m_can_dev(struct net_device *dev) { free_candev(dev); } static struct net_device *alloc_m_can_dev(void) { struct net_device *dev; struct m_can_priv *priv; dev = alloc_candev(sizeof(*priv), 1); if (!dev) return NULL; priv = netdev_priv(dev); netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT); priv->dev = dev; priv->can.bittiming_const = &m_can_bittiming_const; priv->can.data_bittiming_const = &m_can_data_bittiming_const; priv->can.do_set_mode = m_can_set_mode; priv->can.do_get_berr_counter = m_can_get_berr_counter; /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.1 */ priv->can.ctrlmode = CAN_CTRLMODE_FD_NON_ISO; /* CAN_CTRLMODE_FD_NON_ISO can not be changed with M_CAN IP v3.0.1 */ priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_FD; return dev; } static int m_can_open(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); int err; err = clk_prepare_enable(priv->hclk); if (err) return err; err = clk_prepare_enable(priv->cclk); if (err) goto exit_disable_hclk; /* open the can device */ err = open_candev(dev); if (err) { netdev_err(dev, "failed to open can device\n"); goto exit_disable_cclk; } /* register interrupt handler */ err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name, dev); if (err < 0) { netdev_err(dev, "failed to request interrupt\n"); goto exit_irq_fail; } /* start the m_can controller */ m_can_start(dev); can_led_event(dev, CAN_LED_EVENT_OPEN); napi_enable(&priv->napi); netif_start_queue(dev); return 0; exit_irq_fail: close_candev(dev); exit_disable_cclk: clk_disable_unprepare(priv->cclk); exit_disable_hclk: clk_disable_unprepare(priv->hclk); return err; } static void m_can_stop(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); /* disable all interrupts */ m_can_disable_all_interrupts(priv); clk_disable_unprepare(priv->hclk); clk_disable_unprepare(priv->cclk); /* set the state as STOPPED */ priv->can.state = CAN_STATE_STOPPED; } static int m_can_close(struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); netif_stop_queue(dev); napi_disable(&priv->napi); m_can_stop(dev); free_irq(dev->irq, dev); close_candev(dev); can_led_event(dev, CAN_LED_EVENT_STOP); return 0; } static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct m_can_priv *priv = netdev_priv(dev); struct canfd_frame *cf = (struct canfd_frame *)skb->data; u32 id, cccr; int i; if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; netif_stop_queue(dev); if (cf->can_id & CAN_EFF_FLAG) { id = cf->can_id & CAN_EFF_MASK; id |= TX_BUF_XTD; } else { id = ((cf->can_id & CAN_SFF_MASK) << 18); } if (cf->can_id & CAN_RTR_FLAG) id |= TX_BUF_RTR; /* message ram configuration */ m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id); m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16); for (i = 0; i < cf->len; i += 4) m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4), *(u32 *)(cf->data + i)); can_put_echo_skb(skb, dev, 0); if (priv->can.ctrlmode & CAN_CTRLMODE_FD) { cccr = m_can_read(priv, M_CAN_CCCR); cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT); if (can_is_canfd_skb(skb)) { m_can_debug(KERN_INFO "Frame is a CAN FD frame\n"); m_can_debug("BRS active: %s", (cf->flags & CANFD_BRS ? "yes" : "no")); if (cf->flags & CANFD_BRS) cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT; else cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT; } else { cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT; m_can_debug(KERN_INFO "Frame is a normal CAN frame\n"); } m_can_write(priv, M_CAN_CCCR, cccr); } m_can_debug(KERN_INFO "Sending Frame\n"); /* enable first TX buffer to start transfer */ m_can_write(priv, M_CAN_TXBTIE, 0x1); m_can_write(priv, M_CAN_TXBAR, 0x1); return NETDEV_TX_OK; } static const struct net_device_ops m_can_netdev_ops = { .ndo_open = m_can_open, .ndo_stop = m_can_close, .ndo_start_xmit = m_can_start_xmit, .ndo_change_mtu = can_change_mtu, }; static int register_m_can_dev(struct net_device *dev) { dev->flags |= IFF_ECHO; /* we support local echo */ dev->netdev_ops = &m_can_netdev_ops; return register_candev(dev); } static int m_can_of_parse_mram(struct platform_device *pdev, struct m_can_priv *priv) { struct device_node *np = pdev->dev.of_node; struct resource *res; void __iomem *addr; u32 out_val[MRAM_CFG_LEN]; int i, start, end, ret; /* message ram could be shared */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram"); if (!res) return -ENODEV; addr = devm_ioremap(&pdev->dev, res->start, resource_size(res)); if (!addr) return -ENOMEM; /* get message ram configuration */ ret = of_property_read_u32_array(np, "bosch,mram-cfg", out_val, sizeof(out_val) / 4); if (ret) { dev_err(&pdev->dev, "can not get message ram configuration\n"); return -ENODEV; } priv->mram_base = addr; priv->mcfg[MRAM_SIDF].off = out_val[0]; priv->mcfg[MRAM_SIDF].num = out_val[1]; priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off + priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE; priv->mcfg[MRAM_XIDF].num = out_val[2]; priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off + priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE; priv->mcfg[MRAM_RXF0].num = out_val[3] & RXFC_FS_MASK; priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off + priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE; priv->mcfg[MRAM_RXF1].num = out_val[4] & RXFC_FS_MASK; priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off + priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE; priv->mcfg[MRAM_RXB].num = out_val[5]; priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off + priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE; priv->mcfg[MRAM_TXE].num = out_val[6]; priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off + priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE; priv->mcfg[MRAM_TXB].num = out_val[7] & TXBC_NDTB_MASK; dev_dbg(&pdev->dev, "mram_base %p 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", priv->mram_base, priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num, priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num, priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num, priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num, priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num, priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num, priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num); /* initialize the entire Message RAM in use to avoid possible * ECC/parity checksum errors when reading an uninitialized buffer */ start = priv->mcfg[MRAM_SIDF].off; end = priv->mcfg[MRAM_TXB].off + priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE; for (i = start; i < end; i += 4) writel(0x0, priv->mram_base + i); return 0; } static int m_can_plat_probe(struct platform_device *pdev) { struct net_device *dev; struct m_can_priv *priv; struct resource *res; void __iomem *addr; struct clk *hclk, *cclk; int irq, ret; hclk = devm_clk_get(&pdev->dev, "hclk"); cclk = devm_clk_get(&pdev->dev, "cclk"); if (IS_ERR(hclk) || IS_ERR(cclk)) { dev_err(&pdev->dev, "no clock found\n"); return -ENODEV; } res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can"); addr = devm_ioremap_resource(&pdev->dev, res); irq = platform_get_irq_byname(pdev, "int0"); if (IS_ERR(addr) || irq < 0) return -EINVAL; /* allocate the m_can device */ dev = alloc_m_can_dev(); if (!dev) return -ENOMEM; priv = netdev_priv(dev); dev->irq = irq; priv->base = addr; priv->device = &pdev->dev; priv->hclk = hclk; priv->cclk = cclk; priv->can.clock.freq = clk_get_rate(cclk); ret = m_can_of_parse_mram(pdev, priv); if (ret) goto failed_free_dev; platform_set_drvdata(pdev, dev); SET_NETDEV_DEV(dev, &pdev->dev); ret = register_m_can_dev(dev); if (ret) { dev_err(&pdev->dev, "registering %s failed (err=%d)\n", KBUILD_MODNAME, ret); goto failed_free_dev; } devm_can_led_init(dev); dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", KBUILD_MODNAME, priv->base, dev->irq); return 0; failed_free_dev: free_m_can_dev(dev); return ret; } static __maybe_unused int m_can_suspend(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct m_can_priv *priv = netdev_priv(ndev); if (netif_running(ndev)) { netif_stop_queue(ndev); netif_device_detach(ndev); } /* TODO: enter low power */ priv->can.state = CAN_STATE_SLEEPING; return 0; } static __maybe_unused int m_can_resume(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct m_can_priv *priv = netdev_priv(ndev); /* TODO: exit low power */ priv->can.state = CAN_STATE_ERROR_ACTIVE; if (netif_running(ndev)) { netif_device_attach(ndev); netif_start_queue(ndev); } return 0; } static void unregister_m_can_dev(struct net_device *dev) { unregister_candev(dev); } static int m_can_plat_remove(struct platform_device *pdev) { struct net_device *dev = platform_get_drvdata(pdev); unregister_m_can_dev(dev); platform_set_drvdata(pdev, NULL); free_m_can_dev(dev); return 0; } static const struct dev_pm_ops m_can_pmops = { SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume) }; static const struct of_device_id m_can_of_table[] = { { .compatible = "bosch,m_can", .data = NULL }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, m_can_of_table); static struct platform_driver m_can_plat_driver = { .driver = { .name = KBUILD_MODNAME, .of_match_table = m_can_of_table, .pm = &m_can_pmops, }, .probe = m_can_plat_probe, .remove = m_can_plat_remove, }; module_platform_driver(m_can_plat_driver); MODULE_AUTHOR("Dong Aisheng "); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");