Subject: [PATCH 2/2] can: tcan4x5x: Add tcan4x5x driver to the kernel

From: Dan Murphy <[email-masked]>
Date: Mon, 10 Sep 2018 15:12:41 -0500

Add the TCAN4x5x SPI CAN driver.  This device
uses the Bosch MCAN IP core along with a SPI
interface map.  The register and data are
32 bits wide.

Signed-off-by: Dan Murphy <[email-masked]>
---
 drivers/net/can/spi/Kconfig    |    5 +
 drivers/net/can/spi/Makefile   |    1 +
 drivers/net/can/spi/tcan4x5x.c | 1206 ++++++++++++++++++++++++++++++++
 drivers/net/can/spi/tcan4x5x.h |  109 +++
 4 files changed, 1321 insertions(+)
 create mode 100644 drivers/net/can/spi/tcan4x5x.c
 create mode 100644 drivers/net/can/spi/tcan4x5x.h

diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
index 8f2e0dd7b756..8cac6ce37506 100644
--- a/drivers/net/can/spi/Kconfig
+++ b/drivers/net/can/spi/Kconfig
@@ -13,4 +13,9 @@ config CAN_MCP251X
 	---help---
 	  Driver for the Microchip MCP251x SPI CAN controllers.
 
+config CAN_TCAN4X5X
+	tristate "Texas Instruments TCAN4X5X SPI CAN controllers"
+	depends on HAS_DMA
+	---help---
+	  Driver for the Texas Instruments TCAN4X5X SPI CAN controllers.
 endmenu
diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
index f59fa3731073..8ecaace7a920 100644
--- a/drivers/net/can/spi/Makefile
+++ b/drivers/net/can/spi/Makefile
@@ -5,3 +5,4 @@
 
 obj-$(CONFIG_CAN_HI311X)	+= hi311x.o
 obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
+obj-$(CONFIG_CAN_TCAN4X5X)	+= tcan4x5x.o
diff --git a/drivers/net/can/spi/tcan4x5x.c b/drivers/net/can/spi/tcan4x5x.c
new file mode 100644
index 000000000000..ca3753efe35a
--- /dev/null
+++ b/drivers/net/can/spi/tcan4x5x.c
@@ -0,0 +1,1206 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI to CAN driver for the Texas Instruments TCAN4x5x
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/can/core.h>
+#include <linux/can/dev.h>
+#include <linux/can/led.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+
+#include "tcan4x5x.h"
+
+#define DEVICE_NAME "tcan4x5x"
+#define TCAN4X5X_EXT_CLK_DEF	40000000
+
+#define TCAN4X5X_CLEAR_ALL_INT	0xffffffff
+#define TCAN4X5X_SET_ALL_INT	0xffffffff
+
+#define TCAN4X5X_TX_ECHO_SKB_MAX 1
+#define TCAN4X5X_DATA_PKT_OFF	2
+#define TCAN4X5X_WRITE_CMD	(0x61 << 24)
+#define TCAN4X5X_READ_CMD	(0x41 << 24)
+
+#define TCAN4X5X_SID_SHIFT	18
+#define TCAN4X5X_DLC_SHIFT	16
+
+#define TCAN4X5X_ESI_SHIFT	31
+#define TCAN4X5X_XTD_SHIFT	30
+#define TCAN4X5X_RTR_SHIFT	29
+#define TCAN4X5X_FDF_SHIFT	21
+#define TCAN4X5X_BRS_SHIFT	20
+#define TCAN4X5X_DLC_SHIFT	16
+
+#define TCAN4X5X_ESI_MASK	BIT(31)
+#define TCAN4X5X_XTD_MASK	BIT(30)
+#define TCAN4X5X_RTR_MASK	BIT(29)
+
+#define TCAN4X5X_DLC_MASK	0xf0000
+#define TCAN4X5X_SW_RESET	BIT(2)
+
+#define TCAN4X5X_MODE_SEL_MASK		(BIT(7) | BIT(6))
+#define TCAN4X5X_MODE_SLEEP		0x00
+#define TCAN4X5X_MODE_STANDBY		BIT(6)
+#define TCAN4X5X_MODE_NORMAL		BIT(7)
+#define TCAN4X5X_MCAN_CONFIGURED	BIT(5)
+#define TCAN4X5X_WATCHDOG_EN		BIT(3)
+#define TCAN4X5X_WD_60_MS_TIMER		0
+#define TCAN4X5X_WD_600_MS_TIMER	BIT(28)
+#define TCAN4X5X_WD_3_S_TIMER		BIT(29)
+#define TCAN4X5X_WD_6_S_TIMER		(BIT(28) | BIT(29))
+
+/* Nominal Bit Timing & Prescaler Register */
+#define TCAN4X5X_NSJW_SHIFT	25
+#define TCAN4X5X_NBRP_SHIFT	16
+#define TCAN4X5X_NTSEG1_SHIFT	8
+
+#define TCAN4X5X_TDCR_TDCO_SHIFT	8
+
+/* Data Bit Timing & Prescaler Register (DBTP) */
+#define DBTP_TDC		BIT(23)
+#define DBTP_DBRP_SHIFT		16
+#define DBTP_DBRP_MASK		(0x1f << DBTP_DBRP_SHIFT)
+#define DBTP_DTSEG1_SHIFT	8
+#define DBTP_DTSEG1_MASK	(0x1f << DBTP_DTSEG1_SHIFT)
+#define DBTP_DTSEG2_SHIFT	4
+#define DBTP_DTSEG2_MASK	(0xf << DBTP_DTSEG2_SHIFT)
+#define DBTP_DSJW_SHIFT		0
+#define DBTP_DSJW_MASK		(0xf << DBTP_DSJW_SHIFT)
+
+#define TCAN4x5x_QUEUE_LVL_MASK		0x1f
+#define TCAN4x5x_QUEUE_IDX_SHIFT	16
+#define TCAN4x5x_QUEUE_IDX_MASK		0x1f00
+
+#define TCAN4X5X_CANBUSNOM_INT_EN	BIT(14)
+
+#define TCAN4X5X_NUM_TX_BUF	5
+#define TCAN4X5X_TX_QUEUE_SHIFT	24
+#define TCAN4X5X_TX_NDTB_SHIFT	16
+#define TCAN4X5X_TX_BUF_START	0x324
+
+#define TCAN4X5X_NUM_RX_BUF		3
+#define TCAN4X5X_RX_WATER_MARK		2
+#define TCAN4X5X_RX_WATER_MARK_SHIFT	24
+#define TCAN4X5X_RX_FIFO_SZ_SHIFT	16
+#define TCAN4X5X_RX_BUF_START		0x4
+
+#define TCAN4X5X_RX_F1DS_SHIFT	4
+#define TCAN4X5X_RX_RBDS_SHIFT	8
+
+#define TCAN4X5X_RX_FIFO0_MESSAGE	BIT(0)
+#define TCAN4X5X_RX_FIFO1_MESSAGE	BIT(4)
+#define TCAN4X5X_RX_BUFFER_MESSAGE	BIT(19)
+#define TCAN4X5X_RX_INDEX_MASK		0x3f00
+#define TCAN4X5X_RX_INDEX_SHIFT		8
+
+#define TCAN4X5X_RX_ADDR_OFFSET		0x8000
+#define TCAN4X5X_RX_BUF_ADDR_OFFSET	0x8100
+#define TCAN4X5X_RX_ADDR_MASK		0xffff
+
+#define TCAN4X5X_ERR_PROTOCOL_MASK	0x7
+#define TCAN4X5X_ERR_STUFERR		0x1
+#define TCAN4X5X_ERR_FRMERR		0x2
+#define TCAN4X5X_ERR_ACKERR		0x3
+#define TCAN4X5X_ERR_BIT1ERR		0x4
+#define TCAN4X5X_ERR_BIT0ERR		0x5
+#define TCAN4X5X_ERR_CRCERR		0x6
+
+/* Interrupt bits */
+#define TCAN4X5X_CANBUSTERMOPEN_INT_EN	BIT(30)
+#define TCAN4X5X_CANHCANL_INT_EN	BIT(29)
+#define TCAN4X5X_CANHBAT_INT_EN		BIT(28)
+#define TCAN4X5X_CANLGND_INT_EN		BIT(27)
+#define TCAN4X5X_CANBUSOPEN_INT_EN	BIT(26)
+#define TCAN4X5X_CANBUSGND_INT_EN	BIT(25)
+#define TCAN4X5X_CANBUSBAT_INT_EN	BIT(24)
+#define TCAN4X5X_UVSUP_INT_EN		BIT(22)
+#define TCAN4X5X_UVIO_INT_EN		BIT(21)
+#define TCAN4X5X_TSD_INT_EN		BIT(19)
+#define TCAN4X5X_ECCERR_INT_EN		BIT(16)
+#define TCAN4X5X_CANINT_INT_EN		BIT(15)
+#define TCAN4X5X_LWU_INT_EN		BIT(14)
+#define TCAN4X5X_CANSLNT_INT_EN		BIT(10)
+#define TCAN4X5X_CANDOM_INT_EN		BIT(8)
+#define TCAN4X5X_CANBUS_ERR_INT_EN	BIT(5)
+#define TCAN4X5X_BUS_FAULT		BIT(4)
+#define TCAN4X5X_MCAN_INT		BIT(1)
+#define TCAN4X5X_ENABLE_ALL_INT		(TCAN4X5X_MCAN_INT | \
+					TCAN4X5X_BUS_FAULT | \
+					TCAN4X5X_CANBUS_ERR_INT_EN | \
+					TCAN4X5X_CANINT_INT_EN)
+
+/* MCAN Interrupt bits */
+#define TCAN4X5X_MCAN_IR_ARA		BIT(29)
+#define TCAN4X5X_MCAN_IR_PED		BIT(28)
+#define TCAN4X5X_MCAN_IR_PEA		BIT(27)
+#define TCAN4X5X_MCAN_IR_WD		BIT(26)
+#define TCAN4X5X_MCAN_IR_BO		BIT(25)
+#define TCAN4X5X_MCAN_IR_EW		BIT(24)
+#define TCAN4X5X_MCAN_IR_EP		BIT(23)
+#define TCAN4X5X_MCAN_IR_ELO		BIT(22)
+#define TCAN4X5X_MCAN_IR_BEU		BIT(21)
+#define TCAN4X5X_MCAN_IR_BEC		BIT(20)
+#define TCAN4X5X_MCAN_IR_DRX		BIT(19)
+#define TCAN4X5X_MCAN_IR_TOO		BIT(18)
+#define TCAN4X5X_MCAN_IR_MRAF		BIT(17)
+#define TCAN4X5X_MCAN_IR_TSW		BIT(16)
+#define TCAN4X5X_MCAN_IR_TEFL		BIT(15)
+#define TCAN4X5X_MCAN_IR_TEFF		BIT(14)
+#define TCAN4X5X_MCAN_IR_TEFW		BIT(13)
+#define TCAN4X5X_MCAN_IR_TEFN		BIT(12)
+#define TCAN4X5X_MCAN_IR_TFE		BIT(11)
+#define TCAN4X5X_MCAN_IR_TCF		BIT(10)
+#define TCAN4X5X_MCAN_IR_TC		BIT(9)
+#define TCAN4X5X_MCAN_IR_HPM		BIT(8)
+#define TCAN4X5X_MCAN_IR_RF1L		BIT(7)
+#define TCAN4X5X_MCAN_IR_RF1F		BIT(6)
+#define TCAN4X5X_MCAN_IR_RF1W		BIT(5)
+#define TCAN4X5X_MCAN_IR_RF1N		BIT(4)
+#define TCAN4X5X_MCAN_IR_RF0L		BIT(3)
+#define TCAN4X5X_MCAN_IR_RF0F		BIT(2)
+#define TCAN4X5X_MCAN_IR_RF0W		BIT(1)
+#define TCAN4X5X_MCAN_IR_RF0N		BIT(0)
+#define TCAN4X5X_ENABLE_MCAN_INT	(TCAN4X5X_MCAN_IR_TC | \
+					TCAN4X5X_MCAN_IR_RF0N | \
+					TCAN4X5X_MCAN_IR_RF1N | \
+					TCAN4X5X_MCAN_IR_RF0F | \
+					TCAN4X5X_MCAN_IR_RF1F)
+
+/* CCR bits */
+#define TCAN4X5X_CCCR_NISO_BOSCH	BIT(15)
+#define TCAN4X5X_CCCR_TXP		BIT(15)
+#define TCAN4X5X_CCCR_EFBI		BIT(13)
+#define TCAN4X5X_CCCR_PXHD_DIS		BIT(12)
+#define TCAN4X5X_CCCR_BRSE		BIT(9)
+#define TCAN4X5X_CCCR_FDOE		BIT(8)
+#define TCAN4X5X_CCCR_TEST		BIT(7)
+#define TCAN4X5X_CCCR_DAR_DIS		BIT(6)
+#define TCAN4X5X_CCCR_MON		BIT(5)
+#define TCAN4X5X_CCCR_CSR		BIT(4)
+#define TCAN4X5X_CCCR_CSA		BIT(3)
+#define TCAN4X5X_CCCR_ASM		BIT(2)
+#define TCAN4X5X_CCCR_CCE		BIT(1)
+#define TCAN4X5X_CCCR_INIT		BIT(0)
+
+#define TCAN4X5X_EINT0			BIT(0)
+#define TCAN4X5X_EINT1			BIT(1)
+
+struct tcan4x5x_rx_regs {
+	u32 fifo_status_reg;
+	u32 fifo_config_reg;
+	u32 fifo_ack_reg;
+	u32 rx_buf_shift;
+};
+
+struct tcan4x5x_rx_regs tcan4x5x_fifo_regs[] = {
+	{ TCAN4X5X_MCAN_RXF0S, TCAN4X5X_MCAN_RXF0C, TCAN4X5X_MCAN_RXF0A, 0},
+	{ TCAN4X5X_MCAN_RXF1S, TCAN4X5X_MCAN_RXF1C, TCAN4X5X_MCAN_RXF1A, 4},
+	{ TCAN4X5X_MCAN_NDAT1, TCAN4X5X_MCAN_RXBC, TCAN4X5X_MCAN_NDAT1, 8},
+};
+
+enum tcan4x5x_data_size {
+	TCAN4X5X_8_BYTE = 0,
+	TCAN4X5X_12_BYTE,
+	TCAN4X5X_16_BYTE,
+	TCAN4X5X_20_BYTE,
+	TCAN4X5X_24_BYTE,
+	TCAN4X5X_32_BYTE,
+	TCAN4X5X_48_BYTE,
+	TCAN4X5X_64_BYTE,
+};
+
+static const struct can_bittiming_const tcan4x5x_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 2,
+	.tseg1_max = 31,
+	.tseg2_min = 2,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static const struct can_bittiming_const tcan4x5x_data_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 1,
+	.tseg1_max = 32,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static void tcan4x5x_clean(struct net_device *net)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+
+	if (priv->tx_skb || priv->tx_len)
+		net->stats.tx_errors++;
+	if (priv->tx_skb)
+		dev_kfree_skb(priv->tx_skb);
+	if (priv->tx_len)
+		can_free_echo_skb(priv->net, 0);
+
+	priv->tx_skb = NULL;
+	priv->tx_len = 0;
+}
+
+static int regmap_spi_gather_write(void *context, const void *reg,
+				   size_t reg_len, const void *val,
+				   size_t val_len)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+	u32 addr;
+	struct spi_message m;
+	struct spi_transfer t[2] = {{ .tx_buf = &addr, .len = 4, .cs_change = 0,},
+				   { .tx_buf = val, .len = val_len, },};
+
+	addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 2;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
+{
+	u16 *reg = (u16 *)(data);
+	const u32 *val = data + 2;
+
+	return regmap_spi_gather_write(context, reg, 2, val, count - 2);
+}
+
+static int regmap_spi_async_write(void *context,
+				  const void *reg, size_t reg_len,
+				  const void *val, size_t val_len,
+				  struct regmap_async *a)
+{
+	return -ENOTSUPP;
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+	return NULL;
+}
+
+static int tcan4x5x_regmap_read(void *context,
+				const void *reg, size_t reg_size,
+				void *val, size_t val_size)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+
+	u32 addr = TCAN4X5X_READ_CMD | (*((u16 *)reg) << 8) | val_size >> 2;
+
+	return spi_write_then_read(spi, &addr, 4, val, val_size);
+}
+
+static struct regmap_bus tcan4x5x_bus = {
+	.write = tcan4x5x_regmap_write,
+	.gather_write = regmap_spi_gather_write,
+	.async_write = regmap_spi_async_write,
+	.async_alloc = regmap_spi_async_alloc,
+	.read = tcan4x5x_regmap_read,
+	.read_flag_mask = 0x00,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static uint8_t tcan4x5x_dlc_conv(uint8_t input)
+{
+	const static u8 lookup[7] = {12, 16, 20, 24, 32, 48, 64};
+
+	if (input < 9)
+		return input;
+
+	if (input < 16)
+		return lookup[(unsigned int)(input - 9)];
+
+	return 0;
+}
+
+static uint8_t tcan4x5x_txrxesc_value(uint8_t input)
+{
+	const u8 lookup[8] = {8, 12, 16, 20, 24, 32, 48, 64};
+	return lookup[(unsigned int)(input & 0x07)];
+}
+
+static void tcan4x5x_hw_tx(struct tcan4x5x_priv *tcan4x5x)
+{
+	u32 sid, eid, exide, rtr, brs, esi, fdf, xtd, data_len;
+	u32 mcan_address, mcan_tx_element_sz;
+	int queue_stat, queue_lvl, queue_idx;
+	struct canfd_frame *fd_frame;
+	struct can_frame *frame;
+	int tx_element_sz, i, temp;
+	canid_t frame_id;
+	u8 dlc_len;
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_TXFQS, &queue_stat);
+	queue_lvl = queue_stat & TCAN4x5x_QUEUE_LVL_MASK;
+	queue_idx = (queue_stat & TCAN4x5x_QUEUE_IDX_MASK) >> TCAN4x5x_QUEUE_IDX_SHIFT;
+
+	if (tcan4x5x->tx_skb->len == CAN_MTU) {
+		fd_frame = NULL;
+		frame = (struct can_frame *)tcan4x5x->tx_skb->data;
+		frame_id = frame->can_id;
+		dlc_len = frame->can_dlc;
+		data_len = ((dlc_len % 4) + dlc_len) / 4;
+		brs = 0;
+	} else if (tcan4x5x->tx_skb->len == CANFD_MTU) {
+		frame = NULL;
+		fd_frame = (struct canfd_frame *)tcan4x5x->tx_skb->data;
+		frame_id = fd_frame->can_id;
+		dlc_len = fd_frame->len;
+		data_len = ((dlc_len % 4) + dlc_len) / 4;
+		brs = fd_frame->flags & CANFD_BRS;
+		esi = fd_frame->flags & CANFD_ESI;
+		fdf = 1;
+	} else {
+		return;
+	}
+
+	eid = frame_id & CAN_EFF_MASK;
+	rtr = (frame_id & CAN_RTR_FLAG) ? 1 : 0;
+
+	exide = (frame_id & CAN_EFF_FLAG) ? 1 : 0;
+	if (exide) {
+		sid = frame_id & CAN_EFF_MASK;
+		xtd = 1;
+	} else {
+		sid = (frame_id & CAN_SFF_MASK) << TCAN4X5X_SID_SHIFT;
+		xtd = 0;
+	}
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_TXBC, &mcan_address);
+
+	mcan_address = (mcan_address & 0xffff) + TCAN4X5X_MRAM_START;
+	temp = (uint8_t)((mcan_address >> 24) & 0x3F);
+
+	tx_element_sz = temp > 32 ? 32 : temp;
+	temp = (uint8_t)((mcan_address >> 16) & 0x3F);
+
+	tx_element_sz += temp > 32 ? 32 : temp;
+	mcan_address += ((uint32_t)tx_element_sz * queue_idx);
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_TXESC, &mcan_tx_element_sz);
+	tx_element_sz = tcan4x5x_txrxesc_value(mcan_tx_element_sz & 0x07) + 8;
+	mcan_address += ((uint32_t)tx_element_sz * 0);
+
+	tx_element_sz = (tcan4x5x_dlc_conv(dlc_len & 0x0F) + 8) >> 2;
+	if (tcan4x5x_dlc_conv(dlc_len & 0x0F) % 4)
+		tx_element_sz += 1;
+
+	tcan4x5x->spi_tx_buf[0] = esi << TCAN4X5X_ESI_SHIFT |
+				  xtd << TCAN4X5X_XTD_SHIFT |
+				  rtr << TCAN4X5X_RTR_SHIFT | sid;
+
+	tcan4x5x->spi_tx_buf[1] = fdf << TCAN4X5X_FDF_SHIFT |
+		 brs << TCAN4X5X_BRS_SHIFT | dlc_len << TCAN4X5X_DLC_SHIFT;
+
+	if (tcan4x5x->tx_skb->len == CAN_MTU)
+		memcpy(tcan4x5x->spi_tx_buf + TCAN4X5X_DATA_PKT_OFF,
+		       frame->data, dlc_len);
+	else
+		memcpy(tcan4x5x->spi_tx_buf + TCAN4X5X_DATA_PKT_OFF,
+		       fd_frame->data, dlc_len);
+
+	for (i = dlc_len + 1; i < TCAN4X5X_BUF_LEN / 4; i++)
+		tcan4x5x->spi_tx_buf[i] = 0;
+
+	regmap_bulk_write(tcan4x5x->regmap, mcan_address, tcan4x5x->spi_tx_buf,
+			  TCAN4X5X_BUF_LEN);
+
+	regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_TXBAR, (1 << (queue_idx)));
+}
+
+int tcan4x5x_hw_rx(struct tcan4x5x_priv *tcan4x5x)
+{
+	u32 queue_idx, fifo_idx, fifo_start_addr, rx_buf_size, msg_type;
+	u32 data_buffer[TCAN4X5X_BUF_LEN] = {0x0};
+	u32 rx_header[2] = {0x0};
+	struct tcan4x5x_rx_regs *buffer_regs;
+	struct canfd_frame *fd_frame;
+	int dlc_len, data_len;
+	struct sk_buff *skb;
+
+	skb = alloc_canfd_skb(tcan4x5x->net, &fd_frame);
+	if (!skb) {
+		dev_err(&tcan4x5x->spi->dev, "cannot allocate RX skb\n");
+		tcan4x5x->net->stats.rx_dropped++;
+		return -ENOMEM;
+	}
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_INT_FLAG, &msg_type);
+	if (msg_type & TCAN4X5X_RX_FIFO0_MESSAGE) {
+		buffer_regs = &tcan4x5x_fifo_regs[0];
+	} else if (msg_type & TCAN4X5X_RX_FIFO1_MESSAGE) {
+		buffer_regs = &tcan4x5x_fifo_regs[1];
+	} else if (msg_type & TCAN4X5X_RX_BUFFER_MESSAGE) {
+		buffer_regs = &tcan4x5x_fifo_regs[2];
+	} else {
+		buffer_regs = NULL;
+		return -EINVAL;
+	}
+
+	rx_buf_size = TCAN4X5X_BUF_LEN;
+
+	/* Determine which FIFO needs service */
+	regmap_read(tcan4x5x->regmap, buffer_regs->fifo_status_reg, &fifo_idx);
+	if (msg_type & TCAN4X5X_RX_BUFFER_MESSAGE)
+		queue_idx = fifo_idx - 1;
+	else
+		queue_idx = (TCAN4X5X_RX_INDEX_MASK & fifo_idx) >> TCAN4X5X_RX_INDEX_SHIFT;
+
+	/* Calculate the FIFO start address to service */
+	regmap_read(tcan4x5x->regmap, buffer_regs->fifo_config_reg, &fifo_start_addr);
+	fifo_start_addr = (TCAN4X5X_RX_ADDR_MASK & fifo_start_addr);
+	if (msg_type & TCAN4X5X_RX_BUFFER_MESSAGE)
+		fifo_start_addr = fifo_start_addr + TCAN4X5X_RX_BUF_ADDR_OFFSET +
+				  (rx_buf_size * queue_idx);
+	else
+		fifo_start_addr = fifo_start_addr + TCAN4X5X_RX_ADDR_OFFSET +
+				  (rx_buf_size * queue_idx);
+
+	regmap_bulk_read(tcan4x5x->regmap, fifo_start_addr, rx_header, 2);
+
+	dlc_len = (rx_header[1] & TCAN4X5X_DLC_MASK) >> TCAN4X5X_DLC_SHIFT;
+	if (dlc_len <= 8)
+		data_len = dlc_len;
+	else
+		data_len = tcan4x5x_txrxesc_value(dlc_len);
+
+	regmap_bulk_read(tcan4x5x->regmap, fifo_start_addr + 8,
+			 data_buffer, data_len / 4);
+
+	/* Acknowledge receipt of the data */
+	regmap_write(tcan4x5x->regmap, buffer_regs->fifo_ack_reg, queue_idx);
+
+	if (rx_header[0] &  TCAN4X5X_XTD_MASK) {
+		fd_frame->can_id = CAN_EFF_FLAG;
+		fd_frame->can_id |= (rx_header[0] & CAN_EFF_MASK);
+	} else {
+		fd_frame->can_id |= ((rx_header[0] >> TCAN4X5X_SID_SHIFT) &
+				    CAN_SFF_MASK);
+	}
+
+	if (rx_header[0] & TCAN4X5X_RTR_MASK)
+		fd_frame->can_id |= CAN_RTR_FLAG;
+
+	if (rx_header[0] & TCAN4X5X_ESI_MASK) {
+		fd_frame->can_id |= CAN_ERR_FLAG;
+		fd_frame->flags |= CANFD_ESI;
+		netdev_dbg(tcan4x5x->net, "ESI Error\n");
+	}
+
+	fd_frame->len = data_len;
+	memcpy(fd_frame->data, data_buffer, fd_frame->len);
+
+	tcan4x5x->net->stats.rx_packets++;
+	tcan4x5x->net->stats.rx_bytes += fd_frame->len;
+
+	can_led_event(tcan4x5x->net, CAN_LED_EVENT_RX);
+	netif_rx_ni(skb);
+
+	return 0;
+}
+
+static void tcan4x5x_sleep(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *tcan4x5x = spi_get_drvdata(spi);
+
+	regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+			   TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_STANDBY);
+}
+
+static int tcan4x5x_reset(struct net_device *net)
+{
+	struct tcan4x5x_priv *tcan4x5x = netdev_priv(net);
+
+	if (tcan4x5x->reset_gpio) {
+		gpiod_set_value_cansleep(tcan4x5x->reset_gpio, 1);
+		udelay(10);
+		gpiod_set_value_cansleep(tcan4x5x->reset_gpio, 0);
+	} else {
+		regmap_write(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+			     TCAN4X5X_SW_RESET);
+	}
+
+	return 0;
+}
+
+static int tcan4x5x_power_enable(struct regulator *reg, int enable)
+{
+	if (IS_ERR_OR_NULL(reg))
+		return 0;
+
+	if (enable)
+		return regulator_enable(reg);
+	else
+		return regulator_disable(reg);
+}
+
+static irqreturn_t tcan4x5x_can_ist(int irq, void *dev_id)
+{
+	struct tcan4x5x_priv *tcan4x5x = dev_id;
+	struct spi_device *spi = tcan4x5x->spi;
+	struct net_device *net = tcan4x5x->net;
+	enum can_state new_state;
+	int intf, eflag, mcan_intf;
+
+	mutex_lock(&tcan4x5x->tcan4x5x_lock);
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_INT_FLAGS, &intf);
+	if (intf & TCAN4X5X_MCAN_INT)
+		tcan4x5x_hw_rx(tcan4x5x);
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_INT_FLAG, &mcan_intf);
+
+	regmap_read(tcan4x5x->regmap, TCAN4X5X_STATUS, &eflag);
+	/* Update can state */
+	if (eflag & TCAN4X5X_MCAN_IR_BO)
+		new_state = CAN_STATE_BUS_OFF;
+	else if (eflag & TCAN4X5X_MCAN_IR_EP)
+		new_state = CAN_STATE_ERROR_PASSIVE;
+	else if (eflag & TCAN4X5X_MCAN_IR_EW)
+		new_state = CAN_STATE_ERROR_WARNING;
+	else
+		new_state = CAN_STATE_ERROR_ACTIVE;
+
+	if (new_state != tcan4x5x->can.state) {
+		struct can_frame *cf;
+		struct sk_buff *skb;
+		enum can_state rx_state, tx_state;
+		u32 error_count;
+
+		skb = alloc_can_err_skb(net, &cf);
+		if (!skb)
+			goto ist_out;
+
+		regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_ECR, &error_count);
+		cf->data[6] = error_count & 0xff;
+		cf->data[7] = error_count & 0x7f00 >> 8;
+		tx_state = cf->data[6] >= cf->data[7] ? new_state : 0;
+		rx_state = cf->data[6] <= cf->data[7] ? new_state : 0;
+		can_change_state(net, cf, tx_state, rx_state);
+		netif_rx_ni(skb);
+
+		if (new_state == CAN_STATE_BUS_OFF) {
+			can_bus_off(net);
+			if (tcan4x5x->can.restart_ms == 0) {
+				tcan4x5x->force_quit = 1;
+				tcan4x5x_sleep(spi);
+				goto ist_out;
+			}
+		}
+	}
+
+	/* Update bus errors */
+	if ((intf & TCAN4X5X_BUS_FAULT) &&
+	    (tcan4x5x->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
+		struct can_frame *cf;
+		struct sk_buff *skb;
+		u32 psr_err, error_count;
+
+		/* Check for protocol errors */
+		regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_PSR, &psr_err);
+		if (psr_err & TCAN4X5X_ERR_PROTOCOL_MASK) {
+			skb = alloc_can_err_skb(net, &cf);
+			if (!skb)
+				goto ist_out;
+
+			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+			tcan4x5x->can.can_stats.bus_error++;
+			tcan4x5x->net->stats.rx_errors++;
+			if (psr_err & TCAN4X5X_ERR_BIT0ERR)
+				cf->data[2] |= CAN_ERR_PROT_BIT0;
+			else if (psr_err & TCAN4X5X_ERR_BIT1ERR)
+				cf->data[2] |= CAN_ERR_PROT_BIT1;
+			else if (psr_err & TCAN4X5X_ERR_FRMERR)
+				cf->data[2] |= CAN_ERR_PROT_FORM;
+			else if (psr_err & TCAN4X5X_ERR_STUFERR)
+				cf->data[2] |= CAN_ERR_PROT_STUFF;
+			else if (psr_err & TCAN4X5X_ERR_CRCERR)
+				cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+			else if (psr_err & TCAN4X5X_ERR_ACKERR)
+				cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
+
+			regmap_read(tcan4x5x->regmap, TCAN4X5X_MCAN_ECR,
+				    &error_count);
+			cf->data[6] = error_count & 0xff;
+			cf->data[7] = error_count & 0x7f00 >> 8;
+			netdev_dbg(tcan4x5x->net, "Bus Error\n");
+			netif_rx_ni(skb);
+		}
+	}
+
+	if (mcan_intf & TCAN4X5X_MCAN_IR_TC) {
+		net->stats.tx_packets++;
+		net->stats.tx_bytes += tcan4x5x->tx_len - 1;
+		can_led_event(net, CAN_LED_EVENT_TX);
+		if (tcan4x5x->tx_len) {
+			can_get_echo_skb(net, 0);
+			tcan4x5x->tx_len = 0;
+		}
+		netif_wake_queue(net);
+	}
+
+ist_out:
+	regmap_write(tcan4x5x->regmap, TCAN4X5X_INT_FLAGS, TCAN4X5X_CLEAR_ALL_INT);
+	regmap_write(tcan4x5x->regmap, TCAN4X5X_STATUS, TCAN4X5X_CLEAR_ALL_INT);
+	regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_INT_FLAG,
+		     TCAN4X5X_CLEAR_ALL_INT);
+
+	mutex_unlock(&tcan4x5x->tcan4x5x_lock);
+	return IRQ_HANDLED;
+}
+
+static int tcan4x5x_do_set_bittiming(struct net_device *net)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+	struct can_bittiming *bt = &priv->can.bittiming;
+	struct can_bittiming *dbt = &priv->can.data_bittiming;
+	u16 brp, sjw, tseg1, tseg2;
+	int ret;
+	u32 val;
+
+	brp = bt->brp - 1;
+	sjw = bt->sjw - 1;
+	tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
+	tseg2 = bt->phase_seg2 - 1;
+	val = (brp << TCAN4X5X_NBRP_SHIFT) | (sjw << TCAN4X5X_NSJW_SHIFT) |
+		(tseg1 << TCAN4X5X_NTSEG1_SHIFT) | tseg2;
+
+	ret = regmap_write(priv->regmap, TCAN4X5X_MCAN_NBTP, val);
+	if (ret)
+		return -EIO;
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		val = 0;
+		brp = dbt->brp - 1;
+		sjw = dbt->sjw - 1;
+		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
+		tseg2 = dbt->phase_seg2 - 1;
+
+		/* TDC is only needed for bitrates beyond 2.5 MBit/s.
+		 * This is mentioned in the "Bit Time Requirements for CAN FD"
+		 * paper presented at the International CAN Conference 2013
+		 */
+		if (dbt->bitrate > 2500000) {
+			u32 tdco, ssp;
+
+			/* Use the same value of secondary sampling point
+			 * as the data sampling point
+			 */
+			ssp = dbt->sample_point;
+
+			/* Equation based on Bosch's M_CAN User Manual's
+			 * Transmitter Delay Compensation Section
+			 */
+			tdco = (priv->can.clock.freq / 1000) *
+			       ssp / dbt->bitrate;
+
+			/* Max valid TDCO value is 127 */
+			if (tdco > 127) {
+				netdev_warn(net, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
+					    tdco);
+				tdco = 127;
+			}
+
+			val |= DBTP_TDC;
+			ret = regmap_write(priv->regmap, TCAN4X5X_MCAN_TDCR,
+					   tdco << TCAN4X5X_TDCR_TDCO_SHIFT);
+			if (ret)
+				return -EIO;
+		}
+
+		val |= (brp << DBTP_DBRP_SHIFT) |
+			   (sjw << DBTP_DSJW_SHIFT) |
+			   (tseg1 << DBTP_DTSEG1_SHIFT) |
+			   (tseg2 << DBTP_DTSEG2_SHIFT);
+
+		ret = regmap_write(priv->regmap, TCAN4X5X_MCAN_DBTP, val);
+	}
+
+	return ret;
+}
+
+static int tcan4x5x_setup(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *tcan4x5x = spi_get_drvdata(spi);
+	int start_reg = TCAN4X5X_MRAM_START;
+	int end_reg = start_reg + TCAN4X5X_MRAM_SIZE;
+	int ret;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_INT_REG,
+			   TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_INT_EN,
+			   TCAN4X5X_ENABLE_MCAN_INT);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_CCCR,
+			   TCAN4X5X_CCCR_INIT | TCAN4X5X_CCCR_CCE);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_CCCR,
+			   TCAN4X5X_CCCR_INIT | TCAN4X5X_CCCR_CCE |
+			   TCAN4X5X_CCCR_FDOE | TCAN4X5X_CCCR_BRSE);
+	if (ret)
+		return -EIO;
+
+	ret = tcan4x5x_do_set_bittiming(tcan4x5x->net);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_TXESC,
+			   TCAN4X5X_64_BYTE);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_TXBC,
+			   (TCAN4X5X_NUM_TX_BUF << TCAN4X5X_TX_QUEUE_SHIFT |
+			   TCAN4X5X_TX_BUF_START));
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_RXF0C,
+			   (TCAN4X5X_RX_WATER_MARK << TCAN4X5X_RX_WATER_MARK_SHIFT |
+			   TCAN4X5X_NUM_RX_BUF << TCAN4X5X_RX_FIFO_SZ_SHIFT |
+			   TCAN4X5X_RX_BUF_START));
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_RXESC,
+			   (TCAN4X5X_64_BYTE << TCAN4X5X_RX_RBDS_SHIFT |
+			   TCAN4X5X_64_BYTE << TCAN4X5X_RX_F1DS_SHIFT |
+			   TCAN4X5X_64_BYTE));
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_TXBTIE,
+			   TCAN4X5X_SET_ALL_INT);
+	if (ret)
+		return -EIO;
+
+
+	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_write(tcan4x5x->regmap, TCAN4X5X_MCAN_ILE, TCAN4X5X_EINT0);
+	if (ret)
+		return -EIO;
+
+	/* Zero out the MCAN buffers */
+	while (start_reg < end_reg) {
+		regmap_write(tcan4x5x->regmap, start_reg, 0);
+		start_reg += 4;
+	}
+
+	return ret;
+}
+
+static void tcan4x5x_tx_work_handler(struct work_struct *ws)
+{
+	struct tcan4x5x_priv *tcan4x5x = container_of(ws, struct tcan4x5x_priv,
+						tx_work);
+	struct net_device *net = tcan4x5x->net;
+	struct can_frame *frame;
+
+	mutex_lock(&tcan4x5x->tcan4x5x_lock);
+	if (tcan4x5x->tx_skb) {
+		if (tcan4x5x->can.state == CAN_STATE_BUS_OFF) {
+			tcan4x5x_clean(net);
+		} else {
+			frame = (struct can_frame *)tcan4x5x->tx_skb->data;
+			tcan4x5x_hw_tx(tcan4x5x);
+			tcan4x5x->tx_len = 1 + frame->can_dlc;
+			can_put_echo_skb(tcan4x5x->tx_skb, net, 0);
+			tcan4x5x->tx_skb = NULL;
+		}
+	}
+	mutex_unlock(&tcan4x5x->tcan4x5x_lock);
+}
+
+static void tcan4x5x_restart_work_handler(struct work_struct *ws)
+{
+	struct tcan4x5x_priv *tcan4x5x = container_of(ws, struct tcan4x5x_priv,
+						restart_work);
+	struct spi_device *spi = tcan4x5x->spi;
+	struct net_device *net = tcan4x5x->net;
+
+	mutex_lock(&tcan4x5x->tcan4x5x_lock);
+	if (tcan4x5x->after_suspend) {
+		tcan4x5x_reset(net);
+		tcan4x5x_setup(spi);
+		if (tcan4x5x->after_suspend & AFTER_SUSPEND_RESTART) {
+			tcan4x5x_setup(spi);
+		} else if (tcan4x5x->after_suspend & AFTER_SUSPEND_UP) {
+			netif_device_attach(net);
+			tcan4x5x_clean(net);
+			tcan4x5x_setup(spi);
+			netif_wake_queue(net);
+		} else {
+			tcan4x5x_sleep(spi);
+		}
+		tcan4x5x->after_suspend = 0;
+		tcan4x5x->force_quit = 0;
+	}
+
+	if (tcan4x5x->restart_tx) {
+		tcan4x5x->restart_tx = 0;
+		tcan4x5x_reset(net);
+		tcan4x5x_clean(net);
+		tcan4x5x_setup(spi);
+		netif_wake_queue(net);
+	}
+	mutex_unlock(&tcan4x5x->tcan4x5x_lock);
+}
+
+static int tcan4x5x_open(struct net_device *net)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_LOW;
+	int ret;
+
+	ret = open_candev(net);
+	if (ret)
+		return ret;
+
+	mutex_lock(&priv->tcan4x5x_lock);
+	tcan4x5x_power_enable(priv->power, 1);
+
+	priv->force_quit = 0;
+	priv->tx_skb = NULL;
+	priv->tx_len = 0;
+
+	ret = request_threaded_irq(priv->irq, NULL, tcan4x5x_can_ist,
+				   flags, DEVICE_NAME, priv);
+	if (ret) {
+		dev_err(&spi->dev, "failed to acquire irq %d %i\n",
+			priv->irq, ret);
+		goto out_close;
+	}
+
+	priv->wq = alloc_workqueue("tcan4x5x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
+				   0);
+	if (!priv->wq) {
+		ret = -ENOMEM;
+		goto out_free_irq;
+	}
+
+	INIT_WORK(&priv->tx_work, tcan4x5x_tx_work_handler);
+	INIT_WORK(&priv->restart_work, tcan4x5x_restart_work_handler);
+
+	priv->spi_tx_buf = devm_kzalloc(&spi->dev, TCAN4X5X_BUF_LEN,
+					GFP_KERNEL);
+	if (!priv->spi_tx_buf) {
+		ret = -ENOMEM;
+		goto  out_free_wq;
+	}
+
+	priv->spi_rx_buf = devm_kzalloc(&spi->dev, TCAN4X5X_BUF_LEN,
+					GFP_KERNEL);
+	if (!priv->spi_rx_buf) {
+		ret = -ENOMEM;
+		goto  out_free_wq;
+	}
+
+	if (priv->wake_gpio)
+		gpiod_set_value_cansleep(priv->wake_gpio, 1);
+
+	ret = tcan4x5x_reset(net);
+	if (ret)
+		goto out_free_wq;
+
+	ret = tcan4x5x_setup(spi);
+	if (ret)
+		goto out_free_wq;
+
+	can_led_event(net, CAN_LED_EVENT_OPEN);
+	netif_wake_queue(net);
+	mutex_unlock(&priv->tcan4x5x_lock);
+
+	return 0;
+
+ out_free_wq:
+	destroy_workqueue(priv->wq);
+ out_free_irq:
+	free_irq(priv->irq, priv);
+	tcan4x5x_sleep(spi);
+ out_close:
+	tcan4x5x_power_enable(priv->power, 0);
+	close_candev(net);
+	mutex_unlock(&priv->tcan4x5x_lock);
+	return ret;
+}
+
+static int tcan4x5x_stop(struct net_device *net)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+
+	close_candev(net);
+
+	priv->force_quit = 1;
+	free_irq(priv->irq, priv);
+	destroy_workqueue(priv->wq);
+	priv->wq = NULL;
+
+	mutex_lock(&priv->tcan4x5x_lock);
+
+	priv->can.state = CAN_STATE_STOPPED;
+	tcan4x5x_sleep(spi);
+	tcan4x5x_power_enable(priv->power, 0);
+
+	mutex_unlock(&priv->tcan4x5x_lock);
+
+	can_led_event(net, CAN_LED_EVENT_STOP);
+
+	return 0;
+}
+
+static netdev_tx_t tcan4x5x_hard_start_xmit(struct sk_buff *skb,
+					    struct net_device *net)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+	struct spi_device *spi = priv->spi;
+
+	if (priv->tx_skb || priv->tx_len) {
+		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
+		return NETDEV_TX_BUSY;
+	}
+
+	if (can_dropped_invalid_skb(net, skb))
+		return NETDEV_TX_OK;
+
+	netif_stop_queue(net);
+	priv->tx_skb = skb;
+	queue_work(priv->wq, &priv->tx_work);
+
+	return NETDEV_TX_OK;
+}
+
+static int tcan4x5x_do_set_mode(struct net_device *net, enum can_mode mode)
+{
+	struct tcan4x5x_priv *priv = netdev_priv(net);
+
+	switch (mode) {
+	case CAN_MODE_START:
+		tcan4x5x_clean(net);
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		priv->restart_tx = 1;
+		queue_work(priv->wq, &priv->restart_work);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static const struct net_device_ops tcan4x5x_netdev_ops = {
+	.ndo_open = tcan4x5x_open,
+	.ndo_stop = tcan4x5x_stop,
+	.ndo_start_xmit = tcan4x5x_hard_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
+};
+
+static int tcan4x5x_parse_config(struct tcan4x5x_priv *tcan4x5x)
+{
+	tcan4x5x->reset_gpio = devm_gpiod_get_optional(&tcan4x5x->spi->dev,
+						       "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(tcan4x5x->reset_gpio))
+		tcan4x5x->reset_gpio = NULL;
+
+	tcan4x5x->wake_gpio = devm_gpiod_get_optional(&tcan4x5x->spi->dev,
+						      "wake-up", GPIOD_OUT_LOW);
+	if (IS_ERR(tcan4x5x->wake_gpio))
+		tcan4x5x->wake_gpio = NULL;
+
+	tcan4x5x->interrupt_gpio = devm_gpiod_get(&tcan4x5x->spi->dev,
+						  "data-ready", GPIOD_IN);
+	if (IS_ERR(tcan4x5x->interrupt_gpio)) {
+		dev_err(&tcan4x5x->spi->dev, "data-ready gpio not defined\n");
+		return -EINVAL;
+	}
+
+	tcan4x5x->irq = gpiod_to_irq(tcan4x5x->interrupt_gpio);
+
+	tcan4x5x->power = devm_regulator_get_optional(&tcan4x5x->spi->dev,
+						      "vsup");
+	if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
+static const struct regmap_config tcan4x5x_regmap = {
+	.reg_bits = 16,
+	.val_bits = 32,
+	.cache_type = REGCACHE_NONE,
+	.max_register = TCAN4X5X_MAX_REGISTER,
+};
+
+static int tcan4x5x_can_probe(struct spi_device *spi)
+{
+	struct net_device *net;
+	struct tcan4x5x_priv *priv;
+	struct clk *clk;
+	int freq, ret;
+
+	clk = devm_clk_get(&spi->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&spi->dev, "no CAN clock source defined\n");
+		freq = TCAN4X5X_EXT_CLK_DEF;
+	} else {
+		freq = clk_get_rate(clk);
+	}
+
+	/* Sanity check */
+	if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF)
+		return -ERANGE;
+
+	/* Allocate can/net device */
+	net = alloc_candev(sizeof(*priv), TCAN4X5X_TX_ECHO_SKB_MAX);
+	if (!net)
+		return -ENOMEM;
+
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			goto out_free;
+	}
+
+	net->netdev_ops = &tcan4x5x_netdev_ops;
+	net->flags |= IFF_ECHO;
+	net->mtu = CANFD_MTU;
+
+	priv = netdev_priv(net);
+	priv->can.bittiming_const = &tcan4x5x_bittiming_const;
+	priv->can.data_bittiming_const = &tcan4x5x_data_bittiming_const;
+	priv->can.do_set_mode = tcan4x5x_do_set_mode;
+	priv->can.clock.freq = freq;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+				       CAN_CTRLMODE_LISTENONLY |
+				       CAN_CTRLMODE_BERR_REPORTING |
+				       CAN_CTRLMODE_FD |
+				       CAN_CTRLMODE_FD_NON_ISO;
+	priv->net = net;
+	priv->spi = spi;
+	priv->clk = clk;
+	spi_set_drvdata(spi, priv);
+
+	ret = tcan4x5x_parse_config(priv);
+	if (ret)
+		goto out_clk;
+
+	/* Configure the SPI bus */
+	spi->bits_per_word = 32;
+	ret = spi_setup(spi);
+	if (ret)
+		goto out_clk;
+
+	mutex_init(&priv->tcan4x5x_lock);
+
+	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
+					&spi->dev, &tcan4x5x_regmap);
+
+	SET_NETDEV_DEV(net, &spi->dev);
+	ret = register_candev(net);
+	if (ret)
+		goto error_probe;
+
+	devm_can_led_init(net);
+
+	netdev_info(net, "TCAN4X5X successfully initialized.\n");
+	return 0;
+
+error_probe:
+	tcan4x5x_power_enable(priv->power, 0);
+out_clk:
+	if (!IS_ERR(clk))
+		clk_disable_unprepare(clk);
+out_free:
+	free_candev(net);
+	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
+	return ret;
+}
+
+static int tcan4x5x_can_remove(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
+	struct net_device *net = priv->net;
+
+	unregister_candev(net);
+
+	tcan4x5x_power_enable(priv->power, 0);
+
+	if (!IS_ERR(priv->clk))
+		clk_disable_unprepare(priv->clk);
+
+	free_candev(net);
+
+	return 0;
+}
+
+static const struct of_device_id tcan4x5x_of_match[] = {
+	{ .compatible = "ti,tcan4x5x", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
+
+static const struct spi_device_id tcan4x5x_id_table[] = {
+	{
+		.name		= "tcan4x5x",
+		.driver_data	= 0,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
+
+static struct spi_driver tcan4x5x_can_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.of_match_table = tcan4x5x_of_match,
+		.pm = NULL,
+	},
+	.id_table = tcan4x5x_id_table,
+	.probe = tcan4x5x_can_probe,
+	.remove = tcan4x5x_can_remove,
+};
+module_spi_driver(tcan4x5x_can_driver);
+
+MODULE_AUTHOR("Dan Murphy <[email-masked]>");
+MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/can/spi/tcan4x5x.h b/drivers/net/can/spi/tcan4x5x.h
new file mode 100644
index 000000000000..5e14ba571d49
--- /dev/null
+++ b/drivers/net/can/spi/tcan4x5x.h
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI to CAN driver for the Texas Instruments TCA4x5x
+// Flash driver chip family
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#define TCAN4X5X_DEV_ID0	0x00
+#define TCAN4X5X_DEV_ID1	0x04
+#define TCAN4X5X_REV		0x08
+#define TCAN4X5X_STATUS		0x0C
+#define TCAN4X5X_ERROR_STATUS	0x10
+#define TCAN4X5X_CONTROL	0x14
+
+#define TCAN4X5X_CONFIG		0x800
+#define TCAN4X5X_TS_PRESCALE	0x804
+#define TCAN4X5X_TEST_REG	0x808
+#define TCAN4X5X_INT_FLAGS	0x820
+#define TCAN4X5X_MCAN_INT_REG	0x824
+#define TCAN4X5X_INT_EN		0x830
+
+#define TCAN4X5X_MCAN_CREL	0x1000
+#define TCAN4X5X_MCAN_ENDN	0x1004
+#define TCAN4X5X_MCAN_CUST	0x1008
+#define TCAN4X5X_MCAN_DBTP	0x100C
+#define TCAN4X5X_MCAN_TEST	0x1010
+#define TCAN4X5X_MCAN_RWD	0x1014
+#define TCAN4X5X_MCAN_CCCR	0x1018
+#define TCAN4X5X_MCAN_NBTP	0x101C
+#define TCAN4X5X_MCAN_TSCC	0x1020
+#define TCAN4X5X_MCAN_TSCV	0x1024
+#define TCAN4X5X_MCAN_TOCC	0x1028
+#define TCAN4X5X_MCAN_TOCV	0x102C
+#define TCAN4X5X_MCAN_ECR	0x1040
+#define TCAN4X5X_MCAN_PSR	0x1044
+#define TCAN4X5X_MCAN_TDCR	0x1048
+#define TCAN4X5X_MCAN_INT_FLAG	0x1050
+#define TCAN4X5X_MCAN_INT_EN	0x1054
+#define TCAN4X5X_MCAN_ILS	0x1058
+#define TCAN4X5X_MCAN_ILE	0x105C
+#define TCAN4X5X_MCAN_GFC	0x1080
+#define TCAN4X5X_MCAN_SIDFC	0x1084
+#define TCAN4X5X_MCAN_XIDFC	0x1088
+#define TCAN4X5X_MCAN_XIDAM	0x1090
+#define TCAN4X5X_MCAN_HPMS	0x1094
+#define TCAN4X5X_MCAN_NDAT1	0x1098
+#define TCAN4X5X_MCAN_NDAT2	0x109C
+#define TCAN4X5X_MCAN_RXF0C	0x10A0
+#define TCAN4X5X_MCAN_RXF0S	0x10A4
+#define TCAN4X5X_MCAN_RXF0A	0x10A8
+#define TCAN4X5X_MCAN_RXBC	0x10AC
+#define TCAN4X5X_MCAN_RXF1C	0x10B0
+#define TCAN4X5X_MCAN_RXF1S	0x10B4
+#define TCAN4X5X_MCAN_RXF1A	0x10B8
+#define TCAN4X5X_MCAN_RXESC	0x10BC
+#define TCAN4X5X_MCAN_TXBC	0x10C0
+#define TCAN4X5X_MCAN_TXFQS	0x10C4
+#define TCAN4X5X_MCAN_TXESC	0x10C8
+#define TCAN4X5X_MCAN_TXBRP	0x10CC
+#define TCAN4X5X_MCAN_TXBAR	0x10D0
+#define TCAN4X5X_MCAN_TXBCR	0x10D4
+#define TCAN4X5X_MCAN_TXBTO	0x10D8
+#define TCAN4X5X_MCAN_TXBCF	0x10DC
+#define TCAN4X5X_MCAN_TXBTIE	0x10E0
+#define TCAN4X5X_MCAN_TXBCIE	0x10E4
+#define TCAN4X5X_MCAN_TXEFC	0x10F0
+#define TCAN4X5X_MCAN_TXEFS	0x10F4
+#define TCAN4X5X_MCAN_TXEFA	0x10F8
+
+#define TCAN4X5X_MRAM_START	0x8000
+#define TCAN4X5X_MRAM_SIZE	2048
+
+#define TCAN4X5X_MAX_REGISTER	0x8fff
+
+/* 64 byte buffer + 8 byte MCAN header */
+#define TCAN4X5X_BUF_LEN 	72
+
+struct tcan4x5x_priv {
+	struct can_priv can;
+	struct net_device *net;
+	struct regmap *regmap;
+	struct spi_device *spi;
+
+	struct mutex tcan4x5x_lock; /* SPI device lock */
+
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *interrupt_gpio;
+	struct gpio_desc *wake_gpio;
+	struct regulator *power;
+	struct clk *clk;
+
+	struct sk_buff *tx_skb;
+	int tx_len;
+
+	struct workqueue_struct *wq;
+	struct work_struct tx_work;
+	struct work_struct restart_work;
+
+	u32 *spi_tx_buf;
+	u32 *spi_rx_buf;
+
+	int force_quit;
+	int after_suspend;
+#define AFTER_SUSPEND_UP 1
+#define AFTER_SUSPEND_DOWN 2
+#define AFTER_SUSPEND_POWER 4
+#define AFTER_SUSPEND_RESTART 8
+	int restart_tx;
+
+	int irq;
+};
-- 
2.17.0.1855.g63749b2dea