- 根目录:
- drivers
- net
- can
- flexcan.c
/*
* flexcan.c - FLEXCAN CAN controller driver
*
* Copyright (c) 2005-2006 Varma Electronics Oy
* Copyright (c) 2009 Sascha Hauer, Pengutronix
* Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
*
* Based on code originally by Andrey Volkov <avolkov@varma-el.com>
*
* LICENCE:
* 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 version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/netdevice.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/can/platform/flexcan.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/consumer.h>
#define DRV_NAME "flexcan"
/* 8 for RX fifo and 2 error handling */
#define FLEXCAN_NAPI_WEIGHT (8 + 2)
/* FLEXCAN module configuration register (CANMCR) bits */
#define FLEXCAN_MCR_MDIS BIT(31)
#define FLEXCAN_MCR_FRZ BIT(30)
#define FLEXCAN_MCR_FEN BIT(29)
#define FLEXCAN_MCR_HALT BIT(28)
#define FLEXCAN_MCR_NOT_RDY BIT(27)
#define FLEXCAN_MCR_WAK_MSK BIT(26)
#define FLEXCAN_MCR_SOFTRST BIT(25)
#define FLEXCAN_MCR_FRZ_ACK BIT(24)
#define FLEXCAN_MCR_SUPV BIT(23)
#define FLEXCAN_MCR_SLF_WAK BIT(22)
#define FLEXCAN_MCR_WRN_EN BIT(21)
#define FLEXCAN_MCR_LPM_ACK BIT(20)
#define FLEXCAN_MCR_WAK_SRC BIT(19)
#define FLEXCAN_MCR_DOZE BIT(18)
#define FLEXCAN_MCR_SRX_DIS BIT(17)
#define FLEXCAN_MCR_BCC BIT(16)
#define FLEXCAN_MCR_LPRIO_EN BIT(13)
#define FLEXCAN_MCR_AEN BIT(12)
#define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf)
#define FLEXCAN_MCR_IDAM_A (0 << 8)
#define FLEXCAN_MCR_IDAM_B (1 << 8)
#define FLEXCAN_MCR_IDAM_C (2 << 8)
#define FLEXCAN_MCR_IDAM_D (3 << 8)
/* FLEXCAN control register (CANCTRL) bits */
#define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24)
#define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22)
#define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19)
#define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16)
#define FLEXCAN_CTRL_BOFF_MSK BIT(15)
#define FLEXCAN_CTRL_ERR_MSK BIT(14)
#define FLEXCAN_CTRL_CLK_SRC BIT(13)
#define FLEXCAN_CTRL_LPB BIT(12)
#define FLEXCAN_CTRL_TWRN_MSK BIT(11)
#define FLEXCAN_CTRL_RWRN_MSK BIT(10)
#define FLEXCAN_CTRL_SMP BIT(7)
#define FLEXCAN_CTRL_BOFF_REC BIT(6)
#define FLEXCAN_CTRL_TSYN BIT(5)
#define FLEXCAN_CTRL_LBUF BIT(4)
#define FLEXCAN_CTRL_LOM BIT(3)
#define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07)
#define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK)
#define FLEXCAN_CTRL_ERR_STATE \
(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
FLEXCAN_CTRL_BOFF_MSK)
#define FLEXCAN_CTRL_ERR_ALL \
(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
/* FLEXCAN error and status register (ESR) bits */
#define FLEXCAN_ESR_TWRN_INT BIT(17)
#define FLEXCAN_ESR_RWRN_INT BIT(16)
#define FLEXCAN_ESR_BIT1_ERR BIT(15)
#define FLEXCAN_ESR_BIT0_ERR BIT(14)
#define FLEXCAN_ESR_ACK_ERR BIT(13)
#define FLEXCAN_ESR_CRC_ERR BIT(12)
#define FLEXCAN_ESR_FRM_ERR BIT(11)
#define FLEXCAN_ESR_STF_ERR BIT(10)
#define FLEXCAN_ESR_TX_WRN BIT(9)
#define FLEXCAN_ESR_RX_WRN BIT(8)
#define FLEXCAN_ESR_IDLE BIT(7)
#define FLEXCAN_ESR_TXRX BIT(6)
#define FLEXCAN_EST_FLT_CONF_SHIFT (4)
#define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_BOFF_INT BIT(2)
#define FLEXCAN_ESR_ERR_INT BIT(1)
#define FLEXCAN_ESR_WAK_INT BIT(0)
#define FLEXCAN_ESR_ERR_BUS \
(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
#define FLEXCAN_ESR_ERR_STATE \
(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
#define FLEXCAN_ESR_ERR_ALL \
(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
#define FLEXCAN_ESR_ALL_INT \
(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
/* FLEXCAN interrupt flag register (IFLAG) bits */
#define FLEXCAN_TX_BUF_ID 8
#define FLEXCAN_IFLAG_BUF(x) BIT(x)
#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
#define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
#define FLEXCAN_IFLAG_DEFAULT \
(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
/* FLEXCAN message buffers */
#define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24)
#define FLEXCAN_MB_CNT_SRR BIT(22)
#define FLEXCAN_MB_CNT_IDE BIT(21)
#define FLEXCAN_MB_CNT_RTR BIT(20)
#define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16)
#define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff)
#define FLEXCAN_MB_CODE_MASK (0xf0ffffff)
/*
* FLEXCAN hardware feature flags
*
* Below is some version info we got:
* SOC Version IP-Version Glitch- [TR]WRN_INT
* Filter? connected?
* MX25 FlexCAN2 03.00.00.00 no no
* MX28 FlexCAN2 03.00.04.00 yes yes
* MX35 FlexCAN2 03.00.00.00 no no
* MX53 FlexCAN2 03.00.00.00 yes no
* MX6s FlexCAN3 10.00.12.00 yes yes
*
* Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
*/
#define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */
#define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */
/* Structure of the message buffer */
struct flexcan_mb {
u32 can_ctrl;
u32 can_id;
u32 data[2];
};
/* Structure of the hardware registers */
struct flexcan_regs {
u32 mcr; /* 0x00 */
u32 ctrl; /* 0x04 */
u32 timer; /* 0x08 */
u32 _reserved1; /* 0x0c */
u32 rxgmask; /* 0x10 */
u32 rx14mask; /* 0x14 */
u32 rx15mask; /* 0x18 */
u32 ecr; /* 0x1c */
u32 esr; /* 0x20 */
u32 imask2; /* 0x24 */
u32 imask1; /* 0x28 */
u32 iflag2; /* 0x2c */
u32 iflag1; /* 0x30 */
u32 crl2; /* 0x34 */
u32 esr2; /* 0x38 */
u32 imeur; /* 0x3c */
u32 lrfr; /* 0x40 */
u32 crcr; /* 0x44 */
u32 rxfgmask; /* 0x48 */
u32 rxfir; /* 0x4c */
u32 _reserved3[12];
struct flexcan_mb cantxfg[64];
};
struct flexcan_devtype_data {
u32 features; /* hardware controller features */
};
struct flexcan_priv {
struct can_priv can;
struct net_device *dev;
struct napi_struct napi;
void __iomem *base;
u32 reg_esr;
u32 reg_ctrl_default;
struct clk *clk_ipg;
struct clk *clk_per;
struct flexcan_platform_data *pdata;
const struct flexcan_devtype_data *devtype_data;
};
static struct flexcan_devtype_data fsl_p1010_devtype_data = {
.features = FLEXCAN_HAS_BROKEN_ERR_STATE,
};
static struct flexcan_devtype_data fsl_imx28_devtype_data;
static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
.features = FLEXCAN_HAS_V10_FEATURES,
};
static const struct can_bittiming_const flexcan_bittiming_const = {
.name = DRV_NAME,
.tseg1_min = 4,
.tseg1_max = 16,
.tseg2_min = 2,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 256,
.brp_inc = 1,
};
/*
* Abstract off the read/write for arm versus ppc.
*/
#if defined(__BIG_ENDIAN)
static inline u32 flexcan_read(void __iomem *addr)
{
return in_be32(addr);
}
static inline void flexcan_write(u32 val, void __iomem *addr)
{
out_be32(addr, val);
}
#else
static inline u32 flexcan_read(void __iomem *addr)
{
return readl(addr);
}
static inline void flexcan_write(u32 val, void __iomem *addr)
{
writel(val, addr);
}
#endif
/*
* Swtich transceiver on or off
*/
static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on)
{
if (priv->pdata && priv->pdata->transceiver_switch)
priv->pdata->transceiver_switch(on);
}
static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
u32 reg_esr)
{
return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
(reg_esr & FLEXCAN_ESR_ERR_BUS);
}
static inline void flexcan_chip_enable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
u32 reg;
reg = flexcan_read(®s->mcr);
reg &= ~FLEXCAN_MCR_MDIS;
flexcan_write(reg, ®s->mcr);
udelay(10);
}
static inline void flexcan_chip_disable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
u32 reg;
reg = flexcan_read(®s->mcr);
reg |= FLEXCAN_MCR_MDIS;
flexcan_write(reg, ®s->mcr);
}
static int flexcan_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
const struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
u32 reg = flexcan_read(®s->ecr);
bec->txerr = (reg >> 0) & 0xff;
bec->rxerr = (reg >> 8) & 0xff;
return 0;
}
static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
const struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
struct can_frame *cf = (struct can_frame *)skb->data;
u32 can_id;
u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
if (cf->can_id & CAN_EFF_FLAG) {
can_id = cf->can_id & CAN_EFF_MASK;
ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
} else {
can_id = (cf->can_id & CAN_SFF_MASK) << 18;
}
if (cf->can_id & CAN_RTR_FLAG)
ctrl |= FLEXCAN_MB_CNT_RTR;
if (cf->can_dlc > 0) {
u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
}
if (cf->can_dlc > 3) {
u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
flexcan_write(data, ®s->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
}
can_put_echo_skb(skb, dev, 0);
flexcan_write(can_id, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
flexcan_write(ctrl, ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
return NETDEV_TX_OK;
}
static void do_bus_err(struct net_device *dev,
struct can_frame *cf, u32 reg_esr)
{
struct flexcan_priv *priv = netdev_priv(dev);
int rx_errors = 0, tx_errors = 0;
cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
netdev_dbg(dev, "BIT1_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT1;
tx_errors = 1;
}
if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
netdev_dbg(dev, "BIT0_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT0;
tx_errors = 1;
}
if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
netdev_dbg(dev, "ACK_ERR irq\n");
cf->can_id |= CAN_ERR_ACK;
cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
tx_errors = 1;
}
if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
netdev_dbg(dev, "CRC_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT;
cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
rx_errors = 1;
}
if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
netdev_dbg(dev, "FRM_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_FORM;
rx_errors = 1;
}
if (reg_esr & FLEXCAN_ESR_STF_ERR) {
netdev_dbg(dev, "STF_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_STUFF;
rx_errors = 1;
}
priv->can.can_stats.bus_error++;
if (rx_errors)
dev->stats.rx_errors++;
if (tx_errors)
dev->stats.tx_errors++;
}
static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
{
struct sk_buff *skb;
struct can_frame *cf;
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return 0;
do_bus_err(dev, cf, reg_esr);
netif_receive_skb(skb);
dev->stats.rx_packets++;
dev->stats.rx_bytes += cf->can_dlc;
return 1;
}
static void do_state(struct net_device *dev,
struct can_frame *cf, enum can_state new_state)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct can_berr_counter bec;
flexcan_get_berr_counter(dev, &bec);
switch (priv->can.state) {
case CAN_STATE_ERROR_ACTIVE:
/*
* from: ERROR_ACTIVE
* to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
* => : there was a warning int
*/
if (new_state >= CAN_STATE_ERROR_WARNING &&
new_state <= CAN_STATE_BUS_OFF) {
netdev_dbg(dev, "Error Warning IRQ\n");
priv->can.can_stats.error_warning++;
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (bec.txerr > bec.rxerr) ?
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
}
case CAN_STATE_ERROR_WARNING: /* fallthrough */
/*
* from: ERROR_ACTIVE, ERROR_WARNING
* to : ERROR_PASSIVE, BUS_OFF
* => : error passive int
*/
if (new_state >= CAN_STATE_ERROR_PASSIVE &&
new_state <= CAN_STATE_BUS_OFF) {
netdev_dbg(dev, "Error Passive IRQ\n");
priv->can.can_stats.error_passive++;
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (bec.txerr > bec.rxerr) ?
CAN_ERR_CRTL_TX_PASSIVE :
CAN_ERR_CRTL_RX_PASSIVE;
}
break;
case CAN_STATE_BUS_OFF:
netdev_err(dev, "BUG! "
"hardware recovered automatically from BUS_OFF\n");
break;
default:
break;
}
/* process state changes depending on the new state */
switch (new_state) {
case CAN_STATE_ERROR_ACTIVE:
netdev_dbg(dev, "Error Active\n");
cf->can_id |= CAN_ERR_PROT;
cf->data[2] = CAN_ERR_PROT_ACTIVE;
break;
case CAN_STATE_BUS_OFF:
cf->can_id |= CAN_ERR_BUSOFF;
can_bus_off(dev);
break;
default:
break;
}
}
static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct sk_buff *skb;
struct can_frame *cf;
enum can_state new_state;
int flt;
flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
FLEXCAN_ESR_RX_WRN))))
new_state = CAN_STATE_ERROR_ACTIVE;
else
new_state = CAN_STATE_ERROR_WARNING;
} else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
new_state = CAN_STATE_ERROR_PASSIVE;
else
new_state = CAN_STATE_BUS_OFF;
/* state hasn't changed */
if (likely(new_state == priv->can.state))
return 0;
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return 0;
do_state(dev, cf, new_state);
priv->can.state = new_state;
netif_receive_skb(skb);
dev->stats.rx_packets++;
dev->stats.rx_bytes += cf->can_dlc;
return 1;
}
static void flexcan_read_fifo(const struct net_device *dev,
struct can_frame *cf)
{
const struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
struct flexcan_mb __iomem *mb = ®s->cantxfg[0];
u32 reg_ctrl, reg_id;
reg_ctrl = flexcan_read(&mb->can_ctrl);
reg_id = flexcan_read(&mb->can_id);
if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
else
cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
cf->can_id |= CAN_RTR_FLAG;
cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
*(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
*(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
/* mark as read */
flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1);
flexcan_read(®s->timer);
}
static int flexcan_read_frame(struct net_device *dev)
{
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
skb = alloc_can_skb(dev, &cf);
if (unlikely(!skb)) {
stats->rx_dropped++;
return 0;
}
flexcan_read_fifo(dev, cf);
netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
can_led_event(dev, CAN_LED_EVENT_RX);
return 1;
}
static int flexcan_poll(struct napi_struct *napi, int quota)
{
struct net_device *dev = napi->dev;
const struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
u32 reg_iflag1, reg_esr;
int work_done = 0;
/*
* The error bits are cleared on read,
* use saved value from irq handler.
*/
reg_esr = flexcan_read(®s->esr) | priv->reg_esr;
/* handle state changes */
work_done += flexcan_poll_state(dev, reg_esr);
/* handle RX-FIFO */
reg_iflag1 = flexcan_read(®s->iflag1);
while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
work_done < quota) {
work_done += flexcan_read_frame(dev);
reg_iflag1 = flexcan_read(®s->iflag1);
}
/* report bus errors */
if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
work_done += flexcan_poll_bus_err(dev, reg_esr);
if (work_done < quota) {
napi_complete(napi);
/* enable IRQs */
flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
flexcan_write(priv->reg_ctrl_default, ®s->ctrl);
}
return work_done;
}
static irqreturn_t flexcan_irq(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct net_device_stats *stats = &dev->stats;
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
u32 reg_iflag1, reg_esr;
reg_iflag1 = flexcan_read(®s->iflag1);
reg_esr = flexcan_read(®s->esr);
/* ACK all bus error and state change IRQ sources */
if (reg_esr & FLEXCAN_ESR_ALL_INT)
flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, ®s->esr);
/*
* schedule NAPI in case of:
* - rx IRQ
* - state change IRQ
* - bus error IRQ and bus error reporting is activated
*/
if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
(reg_esr & FLEXCAN_ESR_ERR_STATE) ||
flexcan_has_and_handle_berr(priv, reg_esr)) {
/*
* The error bits are cleared on read,
* save them for later use.
*/
priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
flexcan_write(FLEXCAN_IFLAG_DEFAULT &
~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->imask1);
flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
®s->ctrl);
napi_schedule(&priv->napi);
}
/* FIFO overflow */
if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, ®s->iflag1);
dev->stats.rx_over_errors++;
dev->stats.rx_errors++;
}
/* transmission complete interrupt */
if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
stats->tx_bytes += can_get_echo_skb(dev, 0);
stats->tx_packets++;
can_led_event(dev, CAN_LED_EVENT_TX);
flexcan_write((1 << FLEXCAN_TX_BUF_ID), ®s->iflag1);
netif_wake_queue(dev);
}
return IRQ_HANDLED;
}
static void flexcan_set_bittiming(struct net_device *dev)
{
const struct flexcan_priv *priv = netdev_priv(dev);
const struct can_bittiming *bt = &priv->can.bittiming;
struct flexcan_regs __iomem *regs = priv->base;
u32 reg;
reg = flexcan_read(®s->ctrl);
reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
FLEXCAN_CTRL_RJW(0x3) |
FLEXCAN_CTRL_PSEG1(0x7) |
FLEXCAN_CTRL_PSEG2(0x7) |
FLEXCAN_CTRL_PROPSEG(0x7) |
FLEXCAN_CTRL_LPB |
FLEXCAN_CTRL_SMP |
FLEXCAN_CTRL_LOM);
reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
FLEXCAN_CTRL_RJW(bt->sjw - 1) |
FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
reg |= FLEXCAN_CTRL_LPB;
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
reg |= FLEXCAN_CTRL_LOM;
if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
reg |= FLEXCAN_CTRL_SMP;
netdev_info(dev, "writing ctrl=0x%08x\n", reg);
flexcan_write(reg, ®s->ctrl);
/* print chip status */
netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
}
/*
* flexcan_chip_start
*
* this functions is entered with clocks enabled
*
*/
static int flexcan_chip_start(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
unsigned int i;
int err;
u32 reg_mcr, reg_ctrl;
/* enable module */
flexcan_chip_enable(priv);
/* soft reset */
flexcan_write(FLEXCAN_MCR_SOFTRST, ®s->mcr);
udelay(10);
reg_mcr = flexcan_read(®s->mcr);
if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
reg_mcr);
err = -ENODEV;
goto out;
}
flexcan_set_bittiming(dev);
/*
* MCR
*
* enable freeze
* enable fifo
* halt now
* only supervisor access
* enable warning int
* choose format C
* disable local echo
*
*/
reg_mcr = flexcan_read(®s->mcr);
reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS;
netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
flexcan_write(reg_mcr, ®s->mcr);
/*
* CTRL
*
* disable timer sync feature
*
* disable auto busoff recovery
* transmit lowest buffer first
*
* enable tx and rx warning interrupt
* enable bus off interrupt
* (== FLEXCAN_CTRL_ERR_STATE)
*/
reg_ctrl = flexcan_read(®s->ctrl);
reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
FLEXCAN_CTRL_ERR_STATE;
/*
* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
* on most Flexcan cores, too. Otherwise we don't get
* any error warning or passive interrupts.
*/
if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE ||
priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
/* save for later use */
priv->reg_ctrl_default = reg_ctrl;
netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
flexcan_write(reg_ctrl, ®s->ctrl);
for (i = 0; i < ARRAY_SIZE(regs->cantxfg); i++) {
flexcan_write(0, ®s->cantxfg[i].can_ctrl);
flexcan_write(0, ®s->cantxfg[i].can_id);
flexcan_write(0, ®s->cantxfg[i].data[0]);
flexcan_write(0, ®s->cantxfg[i].data[1]);
/* put MB into rx queue */
flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
®s->cantxfg[i].can_ctrl);
}
/* acceptance mask/acceptance code (accept everything) */
flexcan_write(0x0, ®s->rxgmask);
flexcan_write(0x0, ®s->rx14mask);
flexcan_write(0x0, ®s->rx15mask);
if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
flexcan_write(0x0, ®s->rxfgmask);
flexcan_transceiver_switch(priv, 1);
/* synchronize with the can bus */
reg_mcr = flexcan_read(®s->mcr);
reg_mcr &= ~FLEXCAN_MCR_HALT;
flexcan_write(reg_mcr, ®s->mcr);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
/* enable FIFO interrupts */
flexcan_write(FLEXCAN_IFLAG_DEFAULT, ®s->imask1);
/* print chip status */
netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
flexcan_read(®s->mcr), flexcan_read(®s->ctrl));
return 0;
out:
flexcan_chip_disable(priv);
return err;
}
/*
* flexcan_chip_stop
*
* this functions is entered with clocks enabled
*
*/
static void flexcan_chip_stop(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
u32 reg;
/* Disable all interrupts */
flexcan_write(0, ®s->imask1);
/* Disable + halt module */
reg = flexcan_read(®s->mcr);
reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
flexcan_write(reg, ®s->mcr);
flexcan_transceiver_switch(priv, 0);
priv->can.state = CAN_STATE_STOPPED;
return;
}
static int flexcan_open(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
int err;
clk_prepare_enable(priv->clk_ipg);
clk_prepare_enable(priv->clk_per);
err = open_candev(dev);
if (err)
goto out;
err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
if (err)
goto out_close;
/* start chip and queuing */
err = flexcan_chip_start(dev);
if (err)
goto out_close;
can_led_event(dev, CAN_LED_EVENT_OPEN);
napi_enable(&priv->napi);
netif_start_queue(dev);
return 0;
out_close:
close_candev(dev);
out:
clk_disable_unprepare(priv->clk_per);
clk_disable_unprepare(priv->clk_ipg);
return err;
}
static int flexcan_close(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
netif_stop_queue(dev);
napi_disable(&priv->napi);
flexcan_chip_stop(dev);
free_irq(dev->irq, dev);
clk_disable_unprepare(priv->clk_per);
clk_disable_unprepare(priv->clk_ipg);
close_candev(dev);
can_led_event(dev, CAN_LED_EVENT_STOP);
return 0;
}
static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
{
int err;
switch (mode) {
case CAN_MODE_START:
err = flexcan_chip_start(dev);
if (err)
return err;
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static const struct net_device_ops flexcan_netdev_ops = {
.ndo_open = flexcan_open,
.ndo_stop = flexcan_close,
.ndo_start_xmit = flexcan_start_xmit,
};
static int register_flexcandev(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
u32 reg, err;
clk_prepare_enable(priv->clk_ipg);
clk_prepare_enable(priv->clk_per);
/* select "bus clock", chip must be disabled */
flexcan_chip_disable(priv);
reg = flexcan_read(®s->ctrl);
reg |= FLEXCAN_CTRL_CLK_SRC;
flexcan_write(reg, ®s->ctrl);
flexcan_chip_enable(priv);
/* set freeze, halt and activate FIFO, restrict register access */
reg = flexcan_read(®s->mcr);
reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
flexcan_write(reg, ®s->mcr);
/*
* Currently we only support newer versions of this core
* featuring a RX FIFO. Older cores found on some Coldfire
* derivates are not yet supported.
*/
reg = flexcan_read(®s->mcr);
if (!(reg & FLEXCAN_MCR_FEN)) {
netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
err = -ENODEV;
goto out;
}
err = register_candev(dev);
out:
/* disable core and turn off clocks */
flexcan_chip_disable(priv);
clk_disable_unprepare(priv->clk_per);
clk_disable_unprepare(priv->clk_ipg);
return err;
}
static void unregister_flexcandev(struct net_device *dev)
{
unregister_candev(dev);
}
static const struct of_device_id flexcan_of_match[] = {
{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, flexcan_of_match);
static const struct platform_device_id flexcan_id_table[] = {
{ .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, flexcan_id_table);
static int flexcan_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
const struct flexcan_devtype_data *devtype_data;
struct net_device *dev;
struct flexcan_priv *priv;
struct resource *mem;
struct clk *clk_ipg = NULL, *clk_per = NULL;
struct pinctrl *pinctrl;
void __iomem *base;
resource_size_t mem_size;
int err, irq;
u32 clock_freq = 0;
pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
if (IS_ERR(pinctrl))
return PTR_ERR(pinctrl);
if (pdev->dev.of_node)
of_property_read_u32(pdev->dev.of_node,
"clock-frequency", &clock_freq);
if (!clock_freq) {
clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(clk_ipg)) {
dev_err(&pdev->dev, "no ipg clock defined\n");
err = PTR_ERR(clk_ipg);
goto failed_clock;
}
clock_freq = clk_get_rate(clk_ipg);
clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(clk_per)) {
dev_err(&pdev->dev, "no per clock defined\n");
err = PTR_ERR(clk_per);
goto failed_clock;
}
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irq = platform_get_irq(pdev, 0);
if (!mem || irq <= 0) {
err = -ENODEV;
goto failed_get;
}
mem_size = resource_size(mem);
if (!request_mem_region(mem->start, mem_size, pdev->name)) {
err = -EBUSY;
goto failed_get;
}
base = ioremap(mem->start, mem_size);
if (!base) {
err = -ENOMEM;
goto failed_map;
}
dev = alloc_candev(sizeof(struct flexcan_priv), 1);
if (!dev) {
err = -ENOMEM;
goto failed_alloc;
}
of_id = of_match_device(flexcan_of_match, &pdev->dev);
if (of_id) {
devtype_data = of_id->data;
} else if (pdev->id_entry->driver_data) {
devtype_data = (struct flexcan_devtype_data *)
pdev->id_entry->driver_data;
} else {
err = -ENODEV;
goto failed_devtype;
}
dev->netdev_ops = &flexcan_netdev_ops;
dev->irq = irq;
dev->flags |= IFF_ECHO;
priv = netdev_priv(dev);
priv->can.clock.freq = clock_freq;
priv->can.bittiming_const = &flexcan_bittiming_const;
priv->can.do_set_mode = flexcan_set_mode;
priv->can.do_get_berr_counter = flexcan_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
CAN_CTRLMODE_BERR_REPORTING;
priv->base = base;
priv->dev = dev;
priv->clk_ipg = clk_ipg;
priv->clk_per = clk_per;
priv->pdata = pdev->dev.platform_data;
priv->devtype_data = devtype_data;
netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
dev_set_drvdata(&pdev->dev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
err = register_flexcandev(dev);
if (err) {
dev_err(&pdev->dev, "registering netdev failed\n");
goto failed_register;
}
devm_can_led_init(dev);
dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
priv->base, dev->irq);
return 0;
failed_register:
failed_devtype:
free_candev(dev);
failed_alloc:
iounmap(base);
failed_map:
release_mem_region(mem->start, mem_size);
failed_get:
failed_clock:
return err;
}
static int flexcan_remove(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct flexcan_priv *priv = netdev_priv(dev);
struct resource *mem;
unregister_flexcandev(dev);
platform_set_drvdata(pdev, NULL);
iounmap(priv->base);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
free_candev(dev);
return 0;
}
#ifdef CONFIG_PM
static int flexcan_suspend(struct platform_device *pdev, pm_message_t state)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct flexcan_priv *priv = netdev_priv(dev);
flexcan_chip_disable(priv);
if (netif_running(dev)) {
netif_stop_queue(dev);
netif_device_detach(dev);
}
priv->can.state = CAN_STATE_SLEEPING;
return 0;
}
static int flexcan_resume(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct flexcan_priv *priv = netdev_priv(dev);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(dev)) {
netif_device_attach(dev);
netif_start_queue(dev);
}
flexcan_chip_enable(priv);
return 0;
}
#else
#define flexcan_suspend NULL
#define flexcan_resume NULL
#endif
static struct platform_driver flexcan_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
.of_match_table = flexcan_of_match,
},
.probe = flexcan_probe,
.remove = flexcan_remove,
.suspend = flexcan_suspend,
.resume = flexcan_resume,
.id_table = flexcan_id_table,
};
module_platform_driver(flexcan_driver);
MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
"Marc Kleine-Budde <kernel@pengutronix.de>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CAN port driver for flexcan based chip");