/* 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"
/* 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;
cf->data[2] = CAN_ERR_PROT_UNSPEC;
}
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);
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 periperal 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, "error requesting interrupt %x\n", ndev->irq);
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,
};
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) {
dev_err(&pdev->dev, "No IRQ resource\n");
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: %d\n", err);
goto fail_clk;
}
if (clock_select >= ARRAY_SIZE(clock_names)) {
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: %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 (reg_base=%p, irq=%u)\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)) {
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;
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;
if (netif_running(ndev)) {
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);
