Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1525 insertions, 0 deletions

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
new file mode 100644
index 000000000..d4dfa0247
--- /dev/null
+++ b/drivers/net/can/flexcan.c
@@ -0,0 +1,1525 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// flexcan.c - FLEXCAN CAN controller driver
+//
+// Copyright (c) 2005-2006 Varma Electronics Oy
+// Copyright (c) 2009 Sascha Hauer, Pengutronix
+// Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2014 David Jander, Protonic Holland
+//
+// Based on code originally by Andrey Volkov <avolkov@varma-el.com>
+
+#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/rx-offload.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.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_IRMQ		BIT(16)
+#define FLEXCAN_MCR_LPRIO_EN		BIT(13)
+#define FLEXCAN_MCR_AEN			BIT(12)
+/* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
+#define FLEXCAN_MCR_MAXMB(x)		((x) & 0x7f)
+#define FLEXCAN_MCR_IDAM_A		(0x0 << 8)
+#define FLEXCAN_MCR_IDAM_B		(0x1 << 8)
+#define FLEXCAN_MCR_IDAM_C		(0x2 << 8)
+#define FLEXCAN_MCR_IDAM_D		(0x3 << 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 control register 2 (CTRL2) bits */
+#define FLEXCAN_CTRL2_ECRWRE		BIT(29)
+#define FLEXCAN_CTRL2_WRMFRZ		BIT(28)
+#define FLEXCAN_CTRL2_RFFN(x)		(((x) & 0x0f) << 24)
+#define FLEXCAN_CTRL2_TASD(x)		(((x) & 0x1f) << 19)
+#define FLEXCAN_CTRL2_MRP		BIT(18)
+#define FLEXCAN_CTRL2_RRS		BIT(17)
+#define FLEXCAN_CTRL2_EACEN		BIT(16)
+
+/* FLEXCAN memory error control register (MECR) bits */
+#define FLEXCAN_MECR_ECRWRDIS		BIT(31)
+#define FLEXCAN_MECR_HANCEI_MSK		BIT(19)
+#define FLEXCAN_MECR_FANCEI_MSK		BIT(18)
+#define FLEXCAN_MECR_CEI_MSK		BIT(16)
+#define FLEXCAN_MECR_HAERRIE		BIT(15)
+#define FLEXCAN_MECR_FAERRIE		BIT(14)
+#define FLEXCAN_MECR_EXTERRIE		BIT(13)
+#define FLEXCAN_MECR_RERRDIS		BIT(9)
+#define FLEXCAN_MECR_ECCDIS		BIT(8)
+#define FLEXCAN_MECR_NCEFAFRZ		BIT(7)
+
+/* 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 */
+/* Errata ERR005829 step7: Reserve first valid MB */
+#define FLEXCAN_TX_MB_RESERVED_OFF_FIFO		8
+#define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP	0
+#define FLEXCAN_TX_MB				63
+#define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST	(FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP + 1)
+#define FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST	(FLEXCAN_TX_MB - 1)
+#define FLEXCAN_IFLAG_MB(x)		BIT((x) & 0x1f)
+#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
+#define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
+#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
+
+/* FLEXCAN message buffers */
+#define FLEXCAN_MB_CODE_MASK		(0xf << 24)
+#define FLEXCAN_MB_CODE_RX_BUSY_BIT	(0x1 << 24)
+#define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
+#define FLEXCAN_MB_CODE_RX_EMPTY	(0x4 << 24)
+#define FLEXCAN_MB_CODE_RX_FULL		(0x2 << 24)
+#define FLEXCAN_MB_CODE_RX_OVERRUN	(0x6 << 24)
+#define FLEXCAN_MB_CODE_RX_RANSWER	(0xa << 24)
+
+#define FLEXCAN_MB_CODE_TX_INACTIVE	(0x8 << 24)
+#define FLEXCAN_MB_CODE_TX_ABORT	(0x9 << 24)
+#define FLEXCAN_MB_CODE_TX_DATA		(0xc << 24)
+#define FLEXCAN_MB_CODE_TX_TANSWER	(0xe << 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_TIMEOUT_US		(250)
+
+/* FLEXCAN hardware feature flags
+ *
+ * Below is some version info we got:
+ *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT IRQ Err Memory err RTR re-
+ *                                Filter? connected?  Passive detection  ception in MB
+ *   MX25  FlexCAN2  03.00.00.00     no        no        no       no        no
+ *   MX28  FlexCAN2  03.00.04.00    yes       yes        no       no        no
+ *   MX35  FlexCAN2  03.00.00.00     no        no        no       no        no
+ *   MX53  FlexCAN2  03.00.00.00    yes        no        no       no        no
+ *   MX6s  FlexCAN3  10.00.12.00    yes       yes        no       no       yes
+ *   VF610 FlexCAN3  ?               no       yes        no      yes       yes?
+ * LS1021A FlexCAN2  03.00.04.00     no       yes        no       no       yes
+ *
+ * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
+ */
+#define FLEXCAN_QUIRK_BROKEN_WERR_STATE	BIT(1) /* [TR]WRN_INT not connected */
+#define FLEXCAN_QUIRK_DISABLE_RXFG	BIT(2) /* Disable RX FIFO Global mask */
+#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS	BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
+#define FLEXCAN_QUIRK_DISABLE_MECR	BIT(4) /* Disable Memory error detection */
+#define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP	BIT(5) /* Use timestamp based offloading */
+#define FLEXCAN_QUIRK_BROKEN_PERR_STATE	BIT(6) /* No interrupt for error passive */
+#define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN	BIT(7) /* default to BE register access */
+
+/* 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 */
+	union {			/* 0x34 */
+		u32 gfwr_mx28;	/* MX28, MX53 */
+		u32 ctrl2;	/* MX6, VF610 */
+	};
+	u32 esr2;		/* 0x38 */
+	u32 imeur;		/* 0x3c */
+	u32 lrfr;		/* 0x40 */
+	u32 crcr;		/* 0x44 */
+	u32 rxfgmask;		/* 0x48 */
+	u32 rxfir;		/* 0x4c */
+	u32 _reserved3[12];	/* 0x50 */
+	struct flexcan_mb mb[64];	/* 0x80 */
+	/* FIFO-mode:
+	 *			MB
+	 * 0x080...0x08f	0	RX message buffer
+	 * 0x090...0x0df	1-5	reserverd
+	 * 0x0e0...0x0ff	6-7	8 entry ID table
+	 *				(mx25, mx28, mx35, mx53)
+	 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
+	 *				size conf'ed via ctrl2::RFFN
+	 *				(mx6, vf610)
+	 */
+	u32 _reserved4[256];	/* 0x480 */
+	u32 rximr[64];		/* 0x880 */
+	u32 _reserved5[24];	/* 0x980 */
+	u32 gfwr_mx6;		/* 0x9e0 - MX6 */
+	u32 _reserved6[63];	/* 0x9e4 */
+	u32 mecr;		/* 0xae0 */
+	u32 erriar;		/* 0xae4 */
+	u32 erridpr;		/* 0xae8 */
+	u32 errippr;		/* 0xaec */
+	u32 rerrar;		/* 0xaf0 */
+	u32 rerrdr;		/* 0xaf4 */
+	u32 rerrsynr;		/* 0xaf8 */
+	u32 errsr;		/* 0xafc */
+};
+
+struct flexcan_devtype_data {
+	u32 quirks;		/* quirks needed for different IP cores */
+};
+
+struct flexcan_priv {
+	struct can_priv can;
+	struct can_rx_offload offload;
+
+	struct flexcan_regs __iomem *regs;
+	struct flexcan_mb __iomem *tx_mb_reserved;
+	u32 reg_ctrl_default;
+	u32 reg_imask1_default;
+	u32 reg_imask2_default;
+
+	struct clk *clk_ipg;
+	struct clk *clk_per;
+	const struct flexcan_devtype_data *devtype_data;
+	struct regulator *reg_xceiver;
+
+	/* Read and Write APIs */
+	u32 (*read)(void __iomem *addr);
+	void (*write)(u32 val, void __iomem *addr);
+};
+
+static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN,
+};
+
+static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+};
+
+static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+};
+
+static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
+		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+};
+
+static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
+		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+};
+
+static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
+};
+
+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,
+};
+
+/* FlexCAN module is essentially modelled as a little-endian IP in most
+ * SoCs, i.e the registers as well as the message buffer areas are
+ * implemented in a little-endian fashion.
+ *
+ * However there are some SoCs (e.g. LS1021A) which implement the FlexCAN
+ * module in a big-endian fashion (i.e the registers as well as the
+ * message buffer areas are implemented in a big-endian way).
+ *
+ * In addition, the FlexCAN module can be found on SoCs having ARM or
+ * PPC cores. So, we need to abstract off the register read/write
+ * functions, ensuring that these cater to all the combinations of module
+ * endianness and underlying CPU endianness.
+ */
+static inline u32 flexcan_read_be(void __iomem *addr)
+{
+	return ioread32be(addr);
+}
+
+static inline void flexcan_write_be(u32 val, void __iomem *addr)
+{
+	iowrite32be(val, addr);
+}
+
+static inline u32 flexcan_read_le(void __iomem *addr)
+{
+	return ioread32(addr);
+}
+
+static inline void flexcan_write_le(u32 val, void __iomem *addr)
+{
+	iowrite32(val, addr);
+}
+
+static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK);
+
+	priv->write(reg_ctrl, &regs->ctrl);
+}
+
+static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK);
+
+	priv->write(reg_ctrl, &regs->ctrl);
+}
+
+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 int flexcan_chip_enable(struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+	u32 reg;
+
+	reg = priv->read(&regs->mcr);
+	reg &= ~FLEXCAN_MCR_MDIS;
+	priv->write(reg, &regs->mcr);
+
+	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
+		udelay(10);
+
+	if (priv->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->regs;
+	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+	u32 reg;
+
+	reg = priv->read(&regs->mcr);
+	reg |= FLEXCAN_MCR_MDIS;
+	priv->write(reg, &regs->mcr);
+
+	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
+		udelay(10);
+
+	if (!(priv->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->regs;
+	unsigned int timeout;
+	u32 bitrate = priv->can.bittiming.bitrate;
+	u32 reg;
+
+	if (bitrate)
+		timeout = 1000 * 1000 * 10 / bitrate;
+	else
+		timeout = FLEXCAN_TIMEOUT_US / 10;
+
+	reg = priv->read(&regs->mcr);
+	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT;
+	priv->write(reg, &regs->mcr);
+
+	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+		udelay(100);
+
+	if (!(priv->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->regs;
+	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+	u32 reg;
+
+	reg = priv->read(&regs->mcr);
+	reg &= ~FLEXCAN_MCR_HALT;
+	priv->write(reg, &regs->mcr);
+
+	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+		udelay(10);
+
+	if (priv->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->regs;
+	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+
+	priv->write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
+	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
+		udelay(10);
+
+	if (priv->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->regs;
+	u32 reg = priv->read(&regs->ecr);
+
+	bec->txerr = (reg >> 0) & 0xff;
+	bec->rxerr = (reg >> 8) & 0xff;
+
+	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);
+	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 = __flexcan_get_berr_counter(dev, bec);
+
+	clk_disable_unprepare(priv->clk_per);
+ out_disable_ipg:
+	clk_disable_unprepare(priv->clk_ipg);
+
+	return err;
+}
+
+static netdev_tx_t 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->regs;
+	struct can_frame *cf = (struct can_frame *)skb->data;
+	u32 can_id;
+	u32 data;
+	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (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) {
+		data = be32_to_cpup((__be32 *)&cf->data[0]);
+		priv->write(data, &regs->mb[FLEXCAN_TX_MB].data[0]);
+	}
+	if (cf->can_dlc > 4) {
+		data = be32_to_cpup((__be32 *)&cf->data[4]);
+		priv->write(data, &regs->mb[FLEXCAN_TX_MB].data[1]);
+	}
+
+	can_put_echo_skb(skb, dev, 0);
+
+	priv->write(can_id, &regs->mb[FLEXCAN_TX_MB].can_id);
+	priv->write(ctrl, &regs->mb[FLEXCAN_TX_MB].can_ctrl);
+
+	/* Errata ERR005829 step8:
+	 * Write twice INACTIVE(0x8) code to first MB.
+	 */
+	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &priv->tx_mb_reserved->can_ctrl);
+	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &priv->tx_mb_reserved->can_ctrl);
+
+	return NETDEV_TX_OK;
+}
+
+static void flexcan_irq_bus_err(struct net_device *dev, u32 reg_esr)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->regs;
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	bool rx_errors = false, tx_errors = false;
+	u32 timestamp;
+	int err;
+
+	timestamp = priv->read(&regs->timer) << 16;
+
+	skb = alloc_can_err_skb(dev, &cf);
+	if (unlikely(!skb))
+		return;
+
+	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 = true;
+	}
+	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
+		netdev_dbg(dev, "BIT0_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_BIT0;
+		tx_errors = true;
+	}
+	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 = true;
+	}
+	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 = true;
+	}
+	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
+		netdev_dbg(dev, "FRM_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_FORM;
+		rx_errors = true;
+	}
+	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
+		netdev_dbg(dev, "STF_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_STUFF;
+		rx_errors = true;
+	}
+
+	priv->can.can_stats.bus_error++;
+	if (rx_errors)
+		dev->stats.rx_errors++;
+	if (tx_errors)
+		dev->stats.tx_errors++;
+
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		dev->stats.rx_fifo_errors++;
+}
+
+static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->regs;
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	enum can_state new_state, rx_state, tx_state;
+	int flt;
+	struct can_berr_counter bec;
+	u32 timestamp;
+	int err;
+
+	timestamp = priv->read(&regs->timer) << 16;
+
+	flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
+	if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
+		tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
+			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
+		rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
+			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
+		new_state = max(tx_state, rx_state);
+	} else {
+		__flexcan_get_berr_counter(dev, &bec);
+		new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
+			CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
+		rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
+		tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
+	}
+
+	/* state hasn't changed */
+	if (likely(new_state == priv->can.state))
+		return;
+
+	skb = alloc_can_err_skb(dev, &cf);
+	if (unlikely(!skb))
+		return;
+
+	can_change_state(dev, cf, tx_state, rx_state);
+
+	if (unlikely(new_state == CAN_STATE_BUS_OFF))
+		can_bus_off(dev);
+
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		dev->stats.rx_fifo_errors++;
+}
+
+static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
+{
+	return container_of(offload, struct flexcan_priv, offload);
+}
+
+static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
+					 struct can_frame *cf,
+					 u32 *timestamp, unsigned int n)
+{
+	struct flexcan_priv *priv = rx_offload_to_priv(offload);
+	struct flexcan_regs __iomem *regs = priv->regs;
+	struct flexcan_mb __iomem *mb = &regs->mb[n];
+	u32 reg_ctrl, reg_id, reg_iflag1;
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		u32 code;
+
+		do {
+			reg_ctrl = priv->read(&mb->can_ctrl);
+		} while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
+
+		/* is this MB empty? */
+		code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
+		if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
+		    (code != FLEXCAN_MB_CODE_RX_OVERRUN))
+			return 0;
+
+		if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
+			/* This MB was overrun, we lost data */
+			offload->dev->stats.rx_over_errors++;
+			offload->dev->stats.rx_errors++;
+		}
+	} else {
+		reg_iflag1 = priv->read(&regs->iflag1);
+		if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
+			return 0;
+
+		reg_ctrl = priv->read(&mb->can_ctrl);
+	}
+
+	/* increase timstamp to full 32 bit */
+	*timestamp = reg_ctrl << 16;
+
+	reg_id = priv->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(priv->read(&mb->data[0]));
+	*(__be32 *)(cf->data + 4) = cpu_to_be32(priv->read(&mb->data[1]));
+
+	/* mark as read */
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		/* Clear IRQ */
+		if (n < 32)
+			priv->write(BIT(n), &regs->iflag1);
+		else
+			priv->write(BIT(n - 32), &regs->iflag2);
+	} else {
+		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
+	}
+
+	/* Read the Free Running Timer. It is optional but recommended
+	 * to unlock Mailbox as soon as possible and make it available
+	 * for reception.
+	 */
+	priv->read(&regs->timer);
+
+	return 1;
+}
+
+
+static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	u32 iflag1, iflag2;
+
+	iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default &
+		~FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
+	iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default;
+
+	return (u64)iflag2 << 32 | iflag1;
+}
+
+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->regs;
+	irqreturn_t handled = IRQ_NONE;
+	u32 reg_iflag2, reg_esr;
+	enum can_state last_state = priv->can.state;
+
+	/* reception interrupt */
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		u64 reg_iflag;
+		int ret;
+
+		while ((reg_iflag = flexcan_read_reg_iflag_rx(priv))) {
+			handled = IRQ_HANDLED;
+			ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
+								   reg_iflag);
+			if (!ret)
+				break;
+		}
+	} else {
+		u32 reg_iflag1;
+
+		reg_iflag1 = priv->read(&regs->iflag1);
+		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
+			handled = IRQ_HANDLED;
+			can_rx_offload_irq_offload_fifo(&priv->offload);
+		}
+
+		/* FIFO overflow interrupt */
+		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
+			handled = IRQ_HANDLED;
+			priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW,
+				    &regs->iflag1);
+			dev->stats.rx_over_errors++;
+			dev->stats.rx_errors++;
+		}
+	}
+
+	reg_iflag2 = priv->read(&regs->iflag2);
+
+	/* transmission complete interrupt */
+	if (reg_iflag2 & FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB)) {
+		u32 reg_ctrl = priv->read(&regs->mb[FLEXCAN_TX_MB].can_ctrl);
+
+		handled = IRQ_HANDLED;
+		stats->tx_bytes += can_rx_offload_get_echo_skb(&priv->offload,
+							       0, reg_ctrl << 16);
+		stats->tx_packets++;
+		can_led_event(dev, CAN_LED_EVENT_TX);
+
+		/* after sending a RTR frame MB is in RX mode */
+		priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
+			    &regs->mb[FLEXCAN_TX_MB].can_ctrl);
+		priv->write(FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB), &regs->iflag2);
+		netif_wake_queue(dev);
+	}
+
+	reg_esr = priv->read(&regs->esr);
+
+	/* ACK all bus error and state change IRQ sources */
+	if (reg_esr & FLEXCAN_ESR_ALL_INT) {
+		handled = IRQ_HANDLED;
+		priv->write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
+	}
+
+	/* state change interrupt or broken error state quirk fix is enabled */
+	if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
+	    (priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+	                                   FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
+		flexcan_irq_state(dev, reg_esr);
+
+	/* bus error IRQ - handle if bus error reporting is activated */
+	if ((reg_esr & FLEXCAN_ESR_ERR_BUS) &&
+	    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
+		flexcan_irq_bus_err(dev, reg_esr);
+
+	/* availability of error interrupt among state transitions in case
+	 * bus error reporting is de-activated and
+	 * FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled:
+	 *  +--------------------------------------------------------------+
+	 *  | +----------------------------------------------+ [stopped /  |
+	 *  | |                                              |  sleeping] -+
+	 *  +-+-> active <-> warning <-> passive -> bus off -+
+	 *        ___________^^^^^^^^^^^^_______________________________
+	 *        disabled(1)  enabled             disabled
+	 *
+	 * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
+	 */
+	if ((last_state != priv->can.state) &&
+	    (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
+	    !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
+		switch (priv->can.state) {
+		case CAN_STATE_ERROR_ACTIVE:
+			if (priv->devtype_data->quirks &
+			    FLEXCAN_QUIRK_BROKEN_WERR_STATE)
+				flexcan_error_irq_enable(priv);
+			else
+				flexcan_error_irq_disable(priv);
+			break;
+
+		case CAN_STATE_ERROR_WARNING:
+			flexcan_error_irq_enable(priv);
+			break;
+
+		case CAN_STATE_ERROR_PASSIVE:
+		case CAN_STATE_BUS_OFF:
+			flexcan_error_irq_disable(priv);
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return 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->regs;
+	u32 reg;
+
+	reg = priv->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_dbg(dev, "writing ctrl=0x%08x\n", reg);
+	priv->write(reg, &regs->ctrl);
+
+	/* print chip status */
+	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
+		   priv->read(&regs->mcr), priv->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->regs;
+	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
+	int err, i;
+
+	/* 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
+	 * disable local echo
+	 * enable individual RX masking
+	 * choose format C
+	 * set max mailbox number
+	 */
+	reg_mcr = priv->read(&regs->mcr);
+	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
+	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |
+		FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS | FLEXCAN_MCR_IRMQ |
+		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(FLEXCAN_TX_MB);
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+		reg_mcr &= ~FLEXCAN_MCR_FEN;
+	else
+		reg_mcr |= FLEXCAN_MCR_FEN;
+
+	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
+	priv->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 = priv->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->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
+	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
+	else
+		reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
+
+	/* save for later use */
+	priv->reg_ctrl_default = reg_ctrl;
+	/* leave interrupts disabled for now */
+	reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
+	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
+	priv->write(reg_ctrl, &regs->ctrl);
+
+	if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
+		reg_ctrl2 = priv->read(&regs->ctrl2);
+		reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
+		priv->write(reg_ctrl2, &regs->ctrl2);
+	}
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
+			priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
+				    &regs->mb[i].can_ctrl);
+		}
+	} else {
+		/* clear and invalidate unused mailboxes first */
+		for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < ARRAY_SIZE(regs->mb); i++) {
+			priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
+				    &regs->mb[i].can_ctrl);
+		}
+	}
+
+	/* Errata ERR005829: mark first TX mailbox as INACTIVE */
+	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		    &priv->tx_mb_reserved->can_ctrl);
+
+	/* mark TX mailbox as INACTIVE */
+	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		    &regs->mb[FLEXCAN_TX_MB].can_ctrl);
+
+	/* acceptance mask/acceptance code (accept everything) */
+	priv->write(0x0, &regs->rxgmask);
+	priv->write(0x0, &regs->rx14mask);
+	priv->write(0x0, &regs->rx15mask);
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
+		priv->write(0x0, &regs->rxfgmask);
+
+	/* clear acceptance filters */
+	for (i = 0; i < ARRAY_SIZE(regs->mb); i++)
+		priv->write(0, &regs->rximr[i]);
+
+	/* On Vybrid, disable memory error detection interrupts
+	 * and freeze mode.
+	 * This also works around errata e5295 which generates
+	 * false positive memory errors and put the device in
+	 * freeze mode.
+	 */
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
+		/* Follow the protocol as described in "Detection
+		 * and Correction of Memory Errors" to write to
+		 * MECR register
+		 */
+		reg_ctrl2 = priv->read(&regs->ctrl2);
+		reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
+		priv->write(reg_ctrl2, &regs->ctrl2);
+
+		reg_mecr = priv->read(&regs->mecr);
+		reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
+		priv->write(reg_mecr, &regs->mecr);
+		reg_mecr |= FLEXCAN_MECR_ECCDIS;
+		reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
+			      FLEXCAN_MECR_FANCEI_MSK);
+		priv->write(reg_mecr, &regs->mecr);
+	}
+
+	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 interrupts atomically */
+	disable_irq(dev->irq);
+	priv->write(priv->reg_ctrl_default, &regs->ctrl);
+	priv->write(priv->reg_imask1_default, &regs->imask1);
+	priv->write(priv->reg_imask2_default, &regs->imask2);
+	enable_irq(dev->irq);
+
+	/* print chip status */
+	netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
+		   priv->read(&regs->mcr), priv->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 function is entered with clocks enabled
+ */
+static int __flexcan_chip_stop(struct net_device *dev, bool disable_on_error)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->regs;
+	int err;
+
+	/* freeze + disable module */
+	err = flexcan_chip_freeze(priv);
+	if (err && !disable_on_error)
+		return err;
+	err = flexcan_chip_disable(priv);
+	if (err && !disable_on_error)
+		goto out_chip_unfreeze;
+
+	/* Disable all interrupts */
+	priv->write(0, &regs->imask2);
+	priv->write(0, &regs->imask1);
+	priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
+		    &regs->ctrl);
+
+	flexcan_transceiver_disable(priv);
+	priv->can.state = CAN_STATE_STOPPED;
+
+	return 0;
+
+ out_chip_unfreeze:
+	flexcan_chip_unfreeze(priv);
+
+	return err;
+}
+
+static inline int flexcan_chip_stop_disable_on_error(struct net_device *dev)
+{
+	return __flexcan_chip_stop(dev, true);
+}
+
+static inline int flexcan_chip_stop(struct net_device *dev)
+{
+	return __flexcan_chip_stop(dev, false);
+}
+
+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);
+
+	can_rx_offload_enable(&priv->offload);
+	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);
+	can_rx_offload_disable(&priv->offload);
+	flexcan_chip_stop_disable_on_error(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->regs;
+	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 = priv->read(&regs->ctrl);
+	reg |= FLEXCAN_CTRL_CLK_SRC;
+	priv->write(reg, &regs->ctrl);
+
+	err = flexcan_chip_enable(priv);
+	if (err)
+		goto out_chip_disable;
+
+	/* set freeze, halt */
+	err = flexcan_chip_freeze(priv);
+	if (err)
+		goto out_chip_disable;
+
+	/* activate FIFO, restrict register access */
+	reg = priv->read(&regs->mcr);
+	reg |=  FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
+	priv->write(reg, &regs->mcr);
+
+	/* Currently we only support newer versions of this core
+	 * featuring a RX hardware FIFO (although this driver doesn't
+	 * make use of it on some cores). Older cores, found on some
+	 * Coldfire derivates are not tested.
+	 */
+	reg = priv->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,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
+	{ .compatible = "fsl,imx35-flexcan", .data = &fsl_imx25_devtype_data, },
+	{ .compatible = "fsl,imx25-flexcan", .data = &fsl_imx25_devtype_data, },
+	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
+	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
+	{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_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 regulator *reg_xceiver;
+	struct resource *mem;
+	struct clk *clk_ipg = NULL, *clk_per = NULL;
+	struct flexcan_regs __iomem *regs;
+	int err, irq;
+	u32 clock_freq = 0;
+
+	reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
+	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (IS_ERR(reg_xceiver))
+		reg_xceiver = NULL;
+
+	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;
+
+	regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	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;
+
+	platform_set_drvdata(pdev, dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	dev->netdev_ops = &flexcan_netdev_ops;
+	dev->irq = irq;
+	dev->flags |= IFF_ECHO;
+
+	priv = netdev_priv(dev);
+
+	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
+	    devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
+		priv->read = flexcan_read_be;
+		priv->write = flexcan_write_be;
+	} else {
+		priv->read = flexcan_read_le;
+		priv->write = flexcan_write_le;
+	}
+
+	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->regs = regs;
+	priv->clk_ipg = clk_ipg;
+	priv->clk_per = clk_per;
+	priv->devtype_data = devtype_data;
+	priv->reg_xceiver = reg_xceiver;
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
+		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
+	else
+		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
+
+	priv->reg_imask1_default = 0;
+	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
+
+	priv->offload.mailbox_read = flexcan_mailbox_read;
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+		u64 imask;
+
+		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
+		priv->offload.mb_last = FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST;
+
+		imask = GENMASK_ULL(priv->offload.mb_last, priv->offload.mb_first);
+		priv->reg_imask1_default |= imask;
+		priv->reg_imask2_default |= imask >> 32;
+
+		err = can_rx_offload_add_timestamp(dev, &priv->offload);
+	} else {
+		priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
+			FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
+		err = can_rx_offload_add_fifo(dev, &priv->offload, FLEXCAN_NAPI_WEIGHT);
+	}
+	if (err)
+		goto failed_offload;
+
+	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->regs, dev->irq);
+
+	return 0;
+
+ failed_offload:
+ 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);
+	can_rx_offload_del(&priv->offload);
+	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;
+
+	if (netif_running(dev)) {
+		err = flexcan_chip_disable(priv);
+		if (err)
+			return err;
+		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);
+	int err;
+
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	if (netif_running(dev)) {
+		netif_device_attach(dev);
+		netif_start_queue(dev);
+		err = flexcan_chip_enable(priv);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
+
+static struct platform_driver flexcan_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.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");