/* Renesas R-Car CAN device driver * * Copyright (C) 2013 Cogent Embedded, Inc. * Copyright (C) 2013 Renesas Solutions Corp. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include #define RCAR_CAN_DRV_NAME "rcar_can" #define RCAR_SUPPORTED_CLOCKS (BIT(CLKR_CLKP1) | BIT(CLKR_CLKP2) | \ BIT(CLKR_CLKEXT)) /* Mailbox configuration: * mailbox 60 - 63 - Rx FIFO mailboxes * mailbox 56 - 59 - Tx FIFO mailboxes * non-FIFO mailboxes are not used */ #define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */ #define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */ #define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */ #define RCAR_CAN_FIFO_DEPTH 4 /* Mailbox registers structure */ struct rcar_can_mbox_regs { u32 id; /* IDE and RTR bits, SID and EID */ u8 stub; /* Not used */ u8 dlc; /* Data Length Code - bits [0..3] */ u8 data[8]; /* Data Bytes */ u8 tsh; /* Time Stamp Higher Byte */ u8 tsl; /* Time Stamp Lower Byte */ }; struct rcar_can_regs { struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */ u32 mkr_2_9[8]; /* Mask Registers 2-9 */ u32 fidcr[2]; /* FIFO Received ID Compare Register */ u32 mkivlr1; /* Mask Invalid Register 1 */ u32 mier1; /* Mailbox Interrupt Enable Register 1 */ u32 mkr_0_1[2]; /* Mask Registers 0-1 */ u32 mkivlr0; /* Mask Invalid Register 0*/ u32 mier0; /* Mailbox Interrupt Enable Register 0 */ u8 pad_440[0x3c0]; u8 mctl[64]; /* Message Control Registers */ u16 ctlr; /* Control Register */ u16 str; /* Status register */ u8 bcr[3]; /* Bit Configuration Register */ u8 clkr; /* Clock Select Register */ u8 rfcr; /* Receive FIFO Control Register */ u8 rfpcr; /* Receive FIFO Pointer Control Register */ u8 tfcr; /* Transmit FIFO Control Register */ u8 tfpcr; /* Transmit FIFO Pointer Control Register */ u8 eier; /* Error Interrupt Enable Register */ u8 eifr; /* Error Interrupt Factor Judge Register */ u8 recr; /* Receive Error Count Register */ u8 tecr; /* Transmit Error Count Register */ u8 ecsr; /* Error Code Store Register */ u8 cssr; /* Channel Search Support Register */ u8 mssr; /* Mailbox Search Status Register */ u8 msmr; /* Mailbox Search Mode Register */ u16 tsr; /* Time Stamp Register */ u8 afsr; /* Acceptance Filter Support Register */ u8 pad_857; u8 tcr; /* Test Control Register */ u8 pad_859[7]; u8 ier; /* Interrupt Enable Register */ u8 isr; /* Interrupt Status Register */ u8 pad_862; u8 mbsmr; /* Mailbox Search Mask Register */ }; struct rcar_can_priv { struct can_priv can; /* Must be the first member! */ struct net_device *ndev; struct napi_struct napi; struct rcar_can_regs __iomem *regs; struct clk *clk; struct clk *can_clk; u8 tx_dlc[RCAR_CAN_FIFO_DEPTH]; u32 tx_head; u32 tx_tail; u8 clock_select; u8 ier; }; static const struct can_bittiming_const rcar_can_bittiming_const = { .name = RCAR_CAN_DRV_NAME, .tseg1_min = 4, .tseg1_max = 16, .tseg2_min = 2, .tseg2_max = 8, .sjw_max = 4, .brp_min = 1, .brp_max = 1024, .brp_inc = 1, }; /* Control Register bits */ #define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */ #define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */ /* at bus-off entry */ #define RCAR_CAN_CTLR_SLPM (1 << 10) #define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */ #define RCAR_CAN_CTLR_CANM_HALT (1 << 9) #define RCAR_CAN_CTLR_CANM_RESET (1 << 8) #define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8) #define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */ #define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */ #define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */ #define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */ /* Status Register bits */ #define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */ /* FIFO Received ID Compare Registers 0 and 1 bits */ #define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */ #define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */ /* Receive FIFO Control Register bits */ #define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */ #define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */ /* Transmit FIFO Control Register bits */ #define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */ /* Number Status Bits */ #define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */ /* Message Number Status Bits */ #define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */ #define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */ /* for Rx mailboxes 0-31 */ #define RCAR_CAN_N_RX_MKREGS2 8 /* Bit Configuration Register settings */ #define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20) #define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8) #define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4) #define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07) /* Mailbox and Mask Registers bits */ #define RCAR_CAN_IDE (1 << 31) #define RCAR_CAN_RTR (1 << 30) #define RCAR_CAN_SID_SHIFT 18 /* Mailbox Interrupt Enable Register 1 bits */ #define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */ #define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */ /* Interrupt Enable Register bits */ #define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */ #define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */ /* Enable Bit */ #define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */ /* Enable Bit */ /* Interrupt Status Register bits */ #define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */ #define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */ /* Status Bit */ #define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */ /* Status Bit */ /* Error Interrupt Enable Register bits */ #define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */ #define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */ /* Interrupt Enable */ #define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */ #define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */ #define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */ #define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */ #define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */ #define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */ /* Error Interrupt Factor Judge Register bits */ #define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */ #define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */ /* Detect Flag */ #define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */ #define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */ #define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */ #define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */ #define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */ #define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */ /* Error Code Store Register bits */ #define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */ #define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */ #define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */ #define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */ #define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */ #define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */ #define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */ #define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */ #define RCAR_CAN_NAPI_WEIGHT 4 #define MAX_STR_READS 0x100 static void tx_failure_cleanup(struct net_device *ndev) { int i; for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++) can_free_echo_skb(ndev, i); } static void rcar_can_error(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); struct net_device_stats *stats = &ndev->stats; struct can_frame *cf; struct sk_buff *skb; u8 eifr, txerr = 0, rxerr = 0; /* Propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(ndev, &cf); eifr = readb(&priv->regs->eifr); if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) { txerr = readb(&priv->regs->tecr); rxerr = readb(&priv->regs->recr); if (skb) { cf->can_id |= CAN_ERR_CRTL; cf->data[6] = txerr; cf->data[7] = rxerr; } } if (eifr & RCAR_CAN_EIFR_BEIF) { int rx_errors = 0, tx_errors = 0; u8 ecsr; netdev_dbg(priv->ndev, "Bus error interrupt:\n"); if (skb) cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; ecsr = readb(&priv->regs->ecsr); if (ecsr & RCAR_CAN_ECSR_ADEF) { netdev_dbg(priv->ndev, "ACK Delimiter Error\n"); tx_errors++; writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr); if (skb) cf->data[3] = CAN_ERR_PROT_LOC_ACK_DEL; } if (ecsr & RCAR_CAN_ECSR_BE0F) { netdev_dbg(priv->ndev, "Bit Error (dominant)\n"); tx_errors++; writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr); if (skb) cf->data[2] |= CAN_ERR_PROT_BIT0; } if (ecsr & RCAR_CAN_ECSR_BE1F) { netdev_dbg(priv->ndev, "Bit Error (recessive)\n"); tx_errors++; writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr); if (skb) cf->data[2] |= CAN_ERR_PROT_BIT1; } if (ecsr & RCAR_CAN_ECSR_CEF) { netdev_dbg(priv->ndev, "CRC Error\n"); rx_errors++; writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr); if (skb) cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; } if (ecsr & RCAR_CAN_ECSR_AEF) { netdev_dbg(priv->ndev, "ACK Error\n"); tx_errors++; writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr); if (skb) { cf->can_id |= CAN_ERR_ACK; cf->data[3] = CAN_ERR_PROT_LOC_ACK; } } if (ecsr & RCAR_CAN_ECSR_FEF) { netdev_dbg(priv->ndev, "Form Error\n"); rx_errors++; writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr); if (skb) cf->data[2] |= CAN_ERR_PROT_FORM; } if (ecsr & RCAR_CAN_ECSR_SEF) { netdev_dbg(priv->ndev, "Stuff Error\n"); rx_errors++; writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr); if (skb) cf->data[2] |= CAN_ERR_PROT_STUFF; } priv->can.can_stats.bus_error++; ndev->stats.rx_errors += rx_errors; ndev->stats.tx_errors += tx_errors; writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr); } if (eifr & RCAR_CAN_EIFR_EWIF) { netdev_dbg(priv->ndev, "Error warning interrupt\n"); priv->can.state = CAN_STATE_ERROR_WARNING; priv->can.can_stats.error_warning++; /* Clear interrupt condition */ writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr); if (skb) cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING : CAN_ERR_CRTL_RX_WARNING; } if (eifr & RCAR_CAN_EIFR_EPIF) { netdev_dbg(priv->ndev, "Error passive interrupt\n"); priv->can.state = CAN_STATE_ERROR_PASSIVE; priv->can.can_stats.error_passive++; /* Clear interrupt condition */ writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr); if (skb) cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; } if (eifr & RCAR_CAN_EIFR_BOEIF) { netdev_dbg(priv->ndev, "Bus-off entry interrupt\n"); tx_failure_cleanup(ndev); priv->ier = RCAR_CAN_IER_ERSIE; writeb(priv->ier, &priv->regs->ier); priv->can.state = CAN_STATE_BUS_OFF; /* Clear interrupt condition */ writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr); priv->can.can_stats.bus_off++; can_bus_off(ndev); if (skb) cf->can_id |= CAN_ERR_BUSOFF; } if (eifr & RCAR_CAN_EIFR_ORIF) { netdev_dbg(priv->ndev, "Receive overrun error interrupt\n"); ndev->stats.rx_over_errors++; ndev->stats.rx_errors++; writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr); if (skb) { cf->can_id |= CAN_ERR_CRTL; cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; } } if (eifr & RCAR_CAN_EIFR_OLIF) { netdev_dbg(priv->ndev, "Overload Frame Transmission error interrupt\n"); ndev->stats.rx_over_errors++; ndev->stats.rx_errors++; writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr); if (skb) { cf->can_id |= CAN_ERR_PROT; cf->data[2] |= CAN_ERR_PROT_OVERLOAD; } } if (skb) { stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_rx(skb); } } static void rcar_can_tx_done(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); struct net_device_stats *stats = &ndev->stats; u8 isr; while (1) { u8 unsent = readb(&priv->regs->tfcr); unsent = (unsent & RCAR_CAN_TFCR_TFUST) >> RCAR_CAN_TFCR_TFUST_SHIFT; if (priv->tx_head - priv->tx_tail <= unsent) break; stats->tx_packets++; stats->tx_bytes += priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH]; priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0; can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH); priv->tx_tail++; netif_wake_queue(ndev); } /* Clear interrupt */ isr = readb(&priv->regs->isr); writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr); can_led_event(ndev, CAN_LED_EVENT_TX); } static irqreturn_t rcar_can_interrupt(int irq, void *dev_id) { struct net_device *ndev = dev_id; struct rcar_can_priv *priv = netdev_priv(ndev); u8 isr; isr = readb(&priv->regs->isr); if (!(isr & priv->ier)) return IRQ_NONE; if (isr & RCAR_CAN_ISR_ERSF) rcar_can_error(ndev); if (isr & RCAR_CAN_ISR_TXFF) rcar_can_tx_done(ndev); if (isr & RCAR_CAN_ISR_RXFF) { if (napi_schedule_prep(&priv->napi)) { /* Disable Rx FIFO interrupts */ priv->ier &= ~RCAR_CAN_IER_RXFIE; writeb(priv->ier, &priv->regs->ier); __napi_schedule(&priv->napi); } } return IRQ_HANDLED; } static void rcar_can_set_bittiming(struct net_device *dev) { struct rcar_can_priv *priv = netdev_priv(dev); struct can_bittiming *bt = &priv->can.bittiming; u32 bcr; bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) | RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) | RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1); /* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access. * All the registers are big-endian but they get byte-swapped on 32-bit * read/write (but not on 8-bit, contrary to the manuals)... */ writel((bcr << 8) | priv->clock_select, &priv->regs->bcr); } static void rcar_can_start(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); u16 ctlr; int i; /* Set controller to known mode: * - FIFO mailbox mode * - accept all messages * - overrun mode * CAN is in sleep mode after MCU hardware or software reset. */ ctlr = readw(&priv->regs->ctlr); ctlr &= ~RCAR_CAN_CTLR_SLPM; writew(ctlr, &priv->regs->ctlr); /* Go to reset mode */ ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET; writew(ctlr, &priv->regs->ctlr); for (i = 0; i < MAX_STR_READS; i++) { if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST) break; } rcar_can_set_bittiming(ndev); ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */ ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */ /* at bus-off */ ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */ ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */ writew(ctlr, &priv->regs->ctlr); /* Accept all SID and EID */ writel(0, &priv->regs->mkr_2_9[6]); writel(0, &priv->regs->mkr_2_9[7]); /* In FIFO mailbox mode, write "0" to bits 24 to 31 */ writel(0, &priv->regs->mkivlr1); /* Accept all frames */ writel(0, &priv->regs->fidcr[0]); writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]); /* Enable and configure FIFO mailbox interrupts */ writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1); priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE | RCAR_CAN_IER_TXFIE; writeb(priv->ier, &priv->regs->ier); /* Accumulate error codes */ writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr); /* Enable error interrupts */ writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE | (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ? RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE | RCAR_CAN_EIER_OLIE, &priv->regs->eier); priv->can.state = CAN_STATE_ERROR_ACTIVE; /* Go to operation mode */ writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr); for (i = 0; i < MAX_STR_READS; i++) { if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)) break; } /* Enable Rx and Tx FIFO */ writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr); writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr); } static int rcar_can_open(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); int err; err = clk_prepare_enable(priv->clk); if (err) { netdev_err(ndev, "failed to enable peripheral clock, error %d\n", err); goto out; } err = clk_prepare_enable(priv->can_clk); if (err) { netdev_err(ndev, "failed to enable CAN clock, error %d\n", err); goto out_clock; } err = open_candev(ndev); if (err) { netdev_err(ndev, "open_candev() failed, error %d\n", err); goto out_can_clock; } napi_enable(&priv->napi); err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev); if (err) { netdev_err(ndev, "request_irq(%d) failed, error %d\n", ndev->irq, err); goto out_close; } can_led_event(ndev, CAN_LED_EVENT_OPEN); rcar_can_start(ndev); netif_start_queue(ndev); return 0; out_close: napi_disable(&priv->napi); close_candev(ndev); out_can_clock: clk_disable_unprepare(priv->can_clk); out_clock: clk_disable_unprepare(priv->clk); out: return err; } static void rcar_can_stop(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); u16 ctlr; int i; /* Go to (force) reset mode */ ctlr = readw(&priv->regs->ctlr); ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET; writew(ctlr, &priv->regs->ctlr); for (i = 0; i < MAX_STR_READS; i++) { if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST) break; } writel(0, &priv->regs->mier0); writel(0, &priv->regs->mier1); writeb(0, &priv->regs->ier); writeb(0, &priv->regs->eier); /* Go to sleep mode */ ctlr |= RCAR_CAN_CTLR_SLPM; writew(ctlr, &priv->regs->ctlr); priv->can.state = CAN_STATE_STOPPED; } static int rcar_can_close(struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); netif_stop_queue(ndev); rcar_can_stop(ndev); free_irq(ndev->irq, ndev); napi_disable(&priv->napi); clk_disable_unprepare(priv->can_clk); clk_disable_unprepare(priv->clk); close_candev(ndev); can_led_event(ndev, CAN_LED_EVENT_STOP); return 0; } static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct rcar_can_priv *priv = netdev_priv(ndev); struct can_frame *cf = (struct can_frame *)skb->data; u32 data, i; if (can_dropped_invalid_skb(ndev, skb)) return NETDEV_TX_OK; if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE; else /* Standard frame format */ data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT; if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */ data |= RCAR_CAN_RTR; } else { for (i = 0; i < cf->can_dlc; i++) writeb(cf->data[i], &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]); } writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id); writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc); priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc; can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH); priv->tx_head++; /* Start Tx: write 0xff to the TFPCR register to increment * the CPU-side pointer for the transmit FIFO to the next * mailbox location */ writeb(0xff, &priv->regs->tfpcr); /* Stop the queue if we've filled all FIFO entries */ if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH) netif_stop_queue(ndev); return NETDEV_TX_OK; } static const struct net_device_ops rcar_can_netdev_ops = { .ndo_open = rcar_can_open, .ndo_stop = rcar_can_close, .ndo_start_xmit = rcar_can_start_xmit, .ndo_change_mtu = can_change_mtu, }; static void rcar_can_rx_pkt(struct rcar_can_priv *priv) { struct net_device_stats *stats = &priv->ndev->stats; struct can_frame *cf; struct sk_buff *skb; u32 data; u8 dlc; skb = alloc_can_skb(priv->ndev, &cf); if (!skb) { stats->rx_dropped++; return; } data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id); if (data & RCAR_CAN_IDE) cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; else cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK; dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc); cf->can_dlc = get_can_dlc(dlc); if (data & RCAR_CAN_RTR) { cf->can_id |= CAN_RTR_FLAG; } else { for (dlc = 0; dlc < cf->can_dlc; dlc++) cf->data[dlc] = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]); } can_led_event(priv->ndev, CAN_LED_EVENT_RX); stats->rx_bytes += cf->can_dlc; stats->rx_packets++; netif_receive_skb(skb); } static int rcar_can_rx_poll(struct napi_struct *napi, int quota) { struct rcar_can_priv *priv = container_of(napi, struct rcar_can_priv, napi); int num_pkts; for (num_pkts = 0; num_pkts < quota; num_pkts++) { u8 rfcr, isr; isr = readb(&priv->regs->isr); /* Clear interrupt bit */ if (isr & RCAR_CAN_ISR_RXFF) writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr); rfcr = readb(&priv->regs->rfcr); if (rfcr & RCAR_CAN_RFCR_RFEST) break; rcar_can_rx_pkt(priv); /* Write 0xff to the RFPCR register to increment * the CPU-side pointer for the receive FIFO * to the next mailbox location */ writeb(0xff, &priv->regs->rfpcr); } /* All packets processed */ if (num_pkts < quota) { napi_complete(napi); priv->ier |= RCAR_CAN_IER_RXFIE; writeb(priv->ier, &priv->regs->ier); } return num_pkts; } static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode) { switch (mode) { case CAN_MODE_START: rcar_can_start(ndev); netif_wake_queue(ndev); return 0; default: return -EOPNOTSUPP; } } static int rcar_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct rcar_can_priv *priv = netdev_priv(dev); int err; err = clk_prepare_enable(priv->clk); if (err) return err; bec->txerr = readb(&priv->regs->tecr); bec->rxerr = readb(&priv->regs->recr); clk_disable_unprepare(priv->clk); return 0; } static const char * const clock_names[] = { [CLKR_CLKP1] = "clkp1", [CLKR_CLKP2] = "clkp2", [CLKR_CLKEXT] = "can_clk", }; static int rcar_can_probe(struct platform_device *pdev) { struct rcar_can_platform_data *pdata; struct rcar_can_priv *priv; struct net_device *ndev; struct resource *mem; void __iomem *addr; u32 clock_select = CLKR_CLKP1; int err = -ENODEV; int irq; if (pdev->dev.of_node) { of_property_read_u32(pdev->dev.of_node, "renesas,can-clock-select", &clock_select); } else { pdata = dev_get_platdata(&pdev->dev); if (!pdata) { dev_err(&pdev->dev, "No platform data provided!\n"); goto fail; } clock_select = pdata->clock_select; } irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "No IRQ resource\n"); err = irq; goto fail; } mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); addr = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(addr)) { err = PTR_ERR(addr); goto fail; } ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH); if (!ndev) { dev_err(&pdev->dev, "alloc_candev() failed\n"); err = -ENOMEM; goto fail; } priv = netdev_priv(ndev); priv->clk = devm_clk_get(&pdev->dev, "clkp1"); if (IS_ERR(priv->clk)) { err = PTR_ERR(priv->clk); dev_err(&pdev->dev, "cannot get peripheral clock, error %d\n", err); goto fail_clk; } if (!(BIT(clock_select) & RCAR_SUPPORTED_CLOCKS)) { err = -EINVAL; dev_err(&pdev->dev, "invalid CAN clock selected\n"); goto fail_clk; } priv->can_clk = devm_clk_get(&pdev->dev, clock_names[clock_select]); if (IS_ERR(priv->can_clk)) { err = PTR_ERR(priv->can_clk); dev_err(&pdev->dev, "cannot get CAN clock, error %d\n", err); goto fail_clk; } ndev->netdev_ops = &rcar_can_netdev_ops; ndev->irq = irq; ndev->flags |= IFF_ECHO; priv->ndev = ndev; priv->regs = addr; priv->clock_select = clock_select; priv->can.clock.freq = clk_get_rate(priv->can_clk); priv->can.bittiming_const = &rcar_can_bittiming_const; priv->can.do_set_mode = rcar_can_do_set_mode; priv->can.do_get_berr_counter = rcar_can_get_berr_counter; priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING; platform_set_drvdata(pdev, ndev); SET_NETDEV_DEV(ndev, &pdev->dev); netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll, RCAR_CAN_NAPI_WEIGHT); err = register_candev(ndev); if (err) { dev_err(&pdev->dev, "register_candev() failed, error %d\n", err); goto fail_candev; } devm_can_led_init(ndev); dev_info(&pdev->dev, "device registered (regs @ %p, IRQ%d)\n", priv->regs, ndev->irq); return 0; fail_candev: netif_napi_del(&priv->napi); fail_clk: free_candev(ndev); fail: return err; } static int rcar_can_remove(struct platform_device *pdev) { struct net_device *ndev = platform_get_drvdata(pdev); struct rcar_can_priv *priv = netdev_priv(ndev); unregister_candev(ndev); netif_napi_del(&priv->napi); free_candev(ndev); return 0; } static int __maybe_unused rcar_can_suspend(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct rcar_can_priv *priv = netdev_priv(ndev); u16 ctlr; if (!netif_running(ndev)) return 0; netif_stop_queue(ndev); netif_device_detach(ndev); ctlr = readw(&priv->regs->ctlr); ctlr |= RCAR_CAN_CTLR_CANM_HALT; writew(ctlr, &priv->regs->ctlr); ctlr |= RCAR_CAN_CTLR_SLPM; writew(ctlr, &priv->regs->ctlr); priv->can.state = CAN_STATE_SLEEPING; clk_disable(priv->clk); return 0; } static int __maybe_unused rcar_can_resume(struct device *dev) { struct net_device *ndev = dev_get_drvdata(dev); struct rcar_can_priv *priv = netdev_priv(ndev); u16 ctlr; int err; if (!netif_running(ndev)) return 0; err = clk_enable(priv->clk); if (err) { netdev_err(ndev, "clk_enable() failed, error %d\n", err); return err; } ctlr = readw(&priv->regs->ctlr); ctlr &= ~RCAR_CAN_CTLR_SLPM; writew(ctlr, &priv->regs->ctlr); ctlr &= ~RCAR_CAN_CTLR_CANM; writew(ctlr, &priv->regs->ctlr); priv->can.state = CAN_STATE_ERROR_ACTIVE; netif_device_attach(ndev); netif_start_queue(ndev); return 0; } static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume); static const struct of_device_id rcar_can_of_table[] __maybe_unused = { { .compatible = "renesas,can-r8a7778" }, { .compatible = "renesas,can-r8a7779" }, { .compatible = "renesas,can-r8a7790" }, { .compatible = "renesas,can-r8a7791" }, { } }; MODULE_DEVICE_TABLE(of, rcar_can_of_table); static struct platform_driver rcar_can_driver = { .driver = { .name = RCAR_CAN_DRV_NAME, .of_match_table = of_match_ptr(rcar_can_of_table), .pm = &rcar_can_pm_ops, }, .probe = rcar_can_probe, .remove = rcar_can_remove, }; module_platform_driver(rcar_can_driver); MODULE_AUTHOR("Cogent Embedded, Inc."); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC"); MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);