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linux/drivers/net/can/flexcan.c
Oliver Hartkopp c971fa2ae4 can: Unify MTU settings for CAN interfaces 
CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).
Setting the MTU to other values is pointless but it does not really hurt.
With the introduction of the CAN FD support in drivers/net/can a new
function to switch the MTU for CAN FD has been introduced.

This patch makes use of this can_change_mtu() function to check for correct
MTU settings also in legacy CAN (2.0) devices.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-17 09:20:16 +01:00

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/*
* 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/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/regulator/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) & 0x1f)
#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)
#define FLEXCAN_TIMEOUT_US (50)
/*
* 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;
struct regulator *reg_xceiver;
};
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. This
* assumes that PPC uses big-endian registers and everything
* else uses little-endian registers, independent of CPU
* endianess.
*/
#if defined(CONFIG_PPC)
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
static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
{
if (!priv->reg_xceiver)
return 0;
return regulator_enable(priv->reg_xceiver);
}
static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
{
if (!priv->reg_xceiver)
return 0;
return regulator_disable(priv->reg_xceiver);
}
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 int flexcan_chip_enable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = flexcan_read(&regs->mcr);
reg &= ~FLEXCAN_MCR_MDIS;
flexcan_write(reg, &regs->mcr);
while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
usleep_range(10, 20);
if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_disable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = flexcan_read(&regs->mcr);
reg |= FLEXCAN_MCR_MDIS;
flexcan_write(reg, &regs->mcr);
while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
usleep_range(10, 20);
if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_freeze(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
u32 reg;
reg = flexcan_read(&regs->mcr);
reg |= FLEXCAN_MCR_HALT;
flexcan_write(reg, &regs->mcr);
while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
usleep_range(100, 200);
if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = flexcan_read(&regs->mcr);
reg &= ~FLEXCAN_MCR_HALT;
flexcan_write(reg, &regs->mcr);
while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
usleep_range(10, 20);
if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_softreset(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->base;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
usleep_range(10, 20);
if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
return -ETIMEDOUT;
return 0;
}
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(&regs->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, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
}
if (cf->can_dlc > 3) {
u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
}
can_put_echo_skb(skb, dev, 0);
flexcan_write(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
flexcan_write(ctrl, &regs->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 = &regs->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, &regs->iflag1);
flexcan_read(&regs->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(&regs->esr) | priv->reg_esr;
/* handle state changes */
work_done += flexcan_poll_state(dev, reg_esr);
/* handle RX-FIFO */
reg_iflag1 = flexcan_read(&regs->iflag1);
while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
work_done < quota) {
work_done += flexcan_read_frame(dev);
reg_iflag1 = flexcan_read(&regs->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, &regs->imask1);
flexcan_write(priv->reg_ctrl_default, &regs->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(&regs->iflag1);
reg_esr = flexcan_read(&regs->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, &regs->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, &regs->imask1);
flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
&regs->ctrl);
napi_schedule(&priv->napi);
}
/* FIFO overflow */
if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->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), &regs->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(&regs->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, &regs->ctrl);
/* print chip status */
netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
flexcan_read(&regs->mcr), flexcan_read(&regs->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;
int err;
u32 reg_mcr, reg_ctrl;
/* enable module */
err = flexcan_chip_enable(priv);
if (err)
return err;
/* soft reset */
err = flexcan_chip_softreset(priv);
if (err)
goto out_chip_disable;
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(&regs->mcr);
reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
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 |
FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
flexcan_write(reg_mcr, &regs->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(&regs->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, &regs->ctrl);
/* Abort any pending TX, mark Mailbox as INACTIVE */
flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
&regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
/* acceptance mask/acceptance code (accept everything) */
flexcan_write(0x0, &regs->rxgmask);
flexcan_write(0x0, &regs->rx14mask);
flexcan_write(0x0, &regs->rx15mask);
if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
flexcan_write(0x0, &regs->rxfgmask);
err = flexcan_transceiver_enable(priv);
if (err)
goto out_chip_disable;
/* synchronize with the can bus */
err = flexcan_chip_unfreeze(priv);
if (err)
goto out_transceiver_disable;
priv->can.state = CAN_STATE_ERROR_ACTIVE;
/* enable FIFO interrupts */
flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
/* print chip status */
netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
return 0;
out_transceiver_disable:
flexcan_transceiver_disable(priv);
out_chip_disable:
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;
/* freeze + disable module */
flexcan_chip_freeze(priv);
flexcan_chip_disable(priv);
/* Disable all interrupts */
flexcan_write(0, &regs->imask1);
flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
&regs->ctrl);
flexcan_transceiver_disable(priv);
priv->can.state = CAN_STATE_STOPPED;
return;
}
static int flexcan_open(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
int err;
err = clk_prepare_enable(priv->clk_ipg);
if (err)
return err;
err = clk_prepare_enable(priv->clk_per);
if (err)
goto out_disable_ipg;
err = open_candev(dev);
if (err)
goto out_disable_per;
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_free_irq;
can_led_event(dev, CAN_LED_EVENT_OPEN);
napi_enable(&priv->napi);
netif_start_queue(dev);
return 0;
out_free_irq:
free_irq(dev->irq, dev);
out_close:
close_candev(dev);
out_disable_per:
clk_disable_unprepare(priv->clk_per);
out_disable_ipg:
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,
.ndo_change_mtu = can_change_mtu,
};
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;
err = clk_prepare_enable(priv->clk_ipg);
if (err)
return err;
err = clk_prepare_enable(priv->clk_per);
if (err)
goto out_disable_ipg;
/* select "bus clock", chip must be disabled */
err = flexcan_chip_disable(priv);
if (err)
goto out_disable_per;
reg = flexcan_read(&regs->ctrl);
reg |= FLEXCAN_CTRL_CLK_SRC;
flexcan_write(reg, &regs->ctrl);
err = flexcan_chip_enable(priv);
if (err)
goto out_chip_disable;
/* set freeze, halt and activate FIFO, restrict register access */
reg = flexcan_read(&regs->mcr);
reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
flexcan_write(reg, &regs->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(&regs->mcr);
if (!(reg & FLEXCAN_MCR_FEN)) {
netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
err = -ENODEV;
goto out_chip_disable;
}
err = register_candev(dev);
/* disable core and turn off clocks */
out_chip_disable:
flexcan_chip_disable(priv);
out_disable_per:
clk_disable_unprepare(priv->clk_per);
out_disable_ipg:
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,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_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;
void __iomem *base;
int err, irq;
u32 clock_freq = 0;
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");
return PTR_ERR(clk_ipg);
}
clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(clk_per)) {
dev_err(&pdev->dev, "no per clock defined\n");
return PTR_ERR(clk_per);
}
clock_freq = clk_get_rate(clk_per);
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irq = platform_get_irq(pdev, 0);
if (irq <= 0)
return -ENODEV;
base = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(base))
return PTR_ERR(base);
of_id = of_match_device(flexcan_of_match, &pdev->dev);
if (of_id) {
devtype_data = of_id->data;
} else if (platform_get_device_id(pdev)->driver_data) {
devtype_data = (struct flexcan_devtype_data *)
platform_get_device_id(pdev)->driver_data;
} else {
return -ENODEV;
}
dev = alloc_candev(sizeof(struct flexcan_priv), 1);
if (!dev)
return -ENOMEM;
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 = dev_get_platdata(&pdev->dev);
priv->devtype_data = devtype_data;
priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
if (IS_ERR(priv->reg_xceiver))
priv->reg_xceiver = NULL;
netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
platform_set_drvdata(pdev, 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:
free_candev(dev);
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);
unregister_flexcandev(dev);
netif_napi_del(&priv->napi);
free_candev(dev);
return 0;
}
static int __maybe_unused flexcan_suspend(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
int err;
err = flexcan_chip_disable(priv);
if (err)
return err;
if (netif_running(dev)) {
netif_stop_queue(dev);
netif_device_detach(dev);
}
priv->can.state = CAN_STATE_SLEEPING;
return 0;
}
static int __maybe_unused flexcan_resume(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
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);
}
return flexcan_chip_enable(priv);
}
static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
static struct platform_driver flexcan_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
.pm = &flexcan_pm_ops,
.of_match_table = flexcan_of_match,
},
.probe = flexcan_probe,
.remove = flexcan_remove,
.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");
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