diff options
Diffstat (limited to 'drivers/net/can/rcar/rcar_can.c')
| -rw-r--r-- | drivers/net/can/rcar/rcar_can.c | 935 |
1 files changed, 935 insertions, 0 deletions
diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c new file mode 100644 index 000000000..963da8eda --- /dev/null +++ b/drivers/net/can/rcar/rcar_can.c @@ -0,0 +1,935 @@ +/* Renesas R-Car CAN device driver + * + * Copyright (C) 2013 Cogent Embedded, Inc. <source@cogentembedded.com> + * 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 <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/netdevice.h> +#include <linux/platform_device.h> +#include <linux/can/led.h> +#include <linux/can/dev.h> +#include <linux/clk.h> +#include <linux/can/platform/rcar_can.h> +#include <linux/of.h> + +#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_done(napi, num_pkts); + 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 (IRQ%d)\n", 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" }, + { .compatible = "renesas,rcar-gen1-can" }, + { .compatible = "renesas,rcar-gen2-can" }, + { .compatible = "renesas,rcar-gen3-can" }, + { } +}; +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); 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