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Date:   Mon, 21 Sep 2020 15:45:54 +0200
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, linux-can@...r.kernel.org,
        kernel@...gutronix.de, Marc Kleine-Budde <mkl@...gutronix.de>,
        Kurt Van Dijck <dev.kurt@...dijck-laurijssen.be>,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Subject: [PATCH 35/38] can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN

This patch adds support for the Microchip MCP25xxFD SPI CAN controller family.

Tested-by: Kurt Van Dijck <dev.kurt@...dijck-laurijssen.be>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
Link: https://lore.kernel.org/r/20200918172536.2074504-4-mkl@pengutronix.de
---
 drivers/net/can/spi/mcp25xxfd/Makefile        |    1 +
 .../net/can/spi/mcp25xxfd/mcp25xxfd-core.c    | 2907 +++++++++++++++++
 2 files changed, 2908 insertions(+)
 create mode 100644 drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c

diff --git a/drivers/net/can/spi/mcp25xxfd/Makefile b/drivers/net/can/spi/mcp25xxfd/Makefile
index 9dadf0070b42..4e17f592e22e 100644
--- a/drivers/net/can/spi/mcp25xxfd/Makefile
+++ b/drivers/net/can/spi/mcp25xxfd/Makefile
@@ -3,5 +3,6 @@
 obj-$(CONFIG_CAN_MCP25XXFD) += mcp25xxfd.o
 
 mcp25xxfd-objs :=
+mcp25xxfd-objs += mcp25xxfd-core.o
 mcp25xxfd-objs += mcp25xxfd-crc16.o
 mcp25xxfd-objs += mcp25xxfd-regmap.o
diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
new file mode 100644
index 000000000000..10e4b6d07f95
--- /dev/null
+++ b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
@@ -0,0 +1,2907 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// mcp25xxfd - Microchip MCP25xxFD Family CAN controller driver
+//
+// Copyright (c) 2019, 2020 Pengutronix,
+//                          Marc Kleine-Budde <kernel@...gutronix.de>
+//
+// Based on:
+//
+// CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
+//
+// Copyright (c) 2019 Martin Sperl <kernel@...tin.sperl.org>
+//
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+
+#include <asm/unaligned.h>
+
+#include "mcp25xxfd.h"
+
+#define DEVICE_NAME "mcp25xxfd"
+
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp2517fd = {
+	.quirks = MCP25XXFD_QUIRK_MAB_NO_WARN | MCP25XXFD_QUIRK_CRC_REG |
+		MCP25XXFD_QUIRK_CRC_RX | MCP25XXFD_QUIRK_CRC_TX |
+		MCP25XXFD_QUIRK_ECC,
+	.model = MCP25XXFD_MODEL_MCP2517FD,
+};
+
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp2518fd = {
+	.quirks = MCP25XXFD_QUIRK_CRC_REG | MCP25XXFD_QUIRK_CRC_RX |
+		MCP25XXFD_QUIRK_CRC_TX | MCP25XXFD_QUIRK_ECC,
+	.model = MCP25XXFD_MODEL_MCP2518FD,
+};
+
+/* Autodetect model, start with CRC enabled. */
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp25xxfd = {
+	.quirks = MCP25XXFD_QUIRK_CRC_REG | MCP25XXFD_QUIRK_CRC_RX |
+		MCP25XXFD_QUIRK_CRC_TX | MCP25XXFD_QUIRK_ECC,
+	.model = MCP25XXFD_MODEL_MCP25XXFD,
+};
+
+static const struct can_bittiming_const mcp25xxfd_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 2,
+	.tseg1_max = 256,
+	.tseg2_min = 1,
+	.tseg2_max = 128,
+	.sjw_max = 128,
+	.brp_min = 1,
+	.brp_max = 256,
+	.brp_inc = 1,
+};
+
+static const struct can_bittiming_const mcp25xxfd_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 = 256,
+	.brp_inc = 1,
+};
+
+static const char *__mcp25xxfd_get_model_str(enum mcp25xxfd_model model)
+{
+	switch (model) {
+	case MCP25XXFD_MODEL_MCP2517FD:
+		return "MCP2517FD"; break;
+	case MCP25XXFD_MODEL_MCP2518FD:
+		return "MCP2518FD"; break;
+	case MCP25XXFD_MODEL_MCP25XXFD:
+		return "MCP25xxFD"; break;
+	}
+
+	return "<unknown>";
+}
+
+static inline const char *
+mcp25xxfd_get_model_str(const struct mcp25xxfd_priv *priv)
+{
+	return __mcp25xxfd_get_model_str(priv->devtype_data.model);
+}
+
+static const char *mcp25xxfd_get_mode_str(const u8 mode)
+{
+	switch (mode) {
+	case MCP25XXFD_REG_CON_MODE_MIXED:
+		return "Mixed (CAN FD/CAN 2.0)"; break;
+	case MCP25XXFD_REG_CON_MODE_SLEEP:
+		return "Sleep"; break;
+	case MCP25XXFD_REG_CON_MODE_INT_LOOPBACK:
+		return "Internal Loopback"; break;
+	case MCP25XXFD_REG_CON_MODE_LISTENONLY:
+		return "Listen Only"; break;
+	case MCP25XXFD_REG_CON_MODE_CONFIG:
+		return "Configuration"; break;
+	case MCP25XXFD_REG_CON_MODE_EXT_LOOPBACK:
+		return "External Loopback"; break;
+	case MCP25XXFD_REG_CON_MODE_CAN2_0:
+		return "CAN 2.0"; break;
+	case MCP25XXFD_REG_CON_MODE_RESTRICTED:
+		return "Restricted Operation"; break;
+	}
+
+	return "<unknown>";
+}
+
+static inline int mcp25xxfd_vdd_enable(const struct mcp25xxfd_priv *priv)
+{
+	if (!priv->reg_vdd)
+		return 0;
+
+	return regulator_enable(priv->reg_vdd);
+}
+
+static inline int mcp25xxfd_vdd_disable(const struct mcp25xxfd_priv *priv)
+{
+	if (!priv->reg_vdd)
+		return 0;
+
+	return regulator_disable(priv->reg_vdd);
+}
+
+static inline int
+mcp25xxfd_transceiver_enable(const struct mcp25xxfd_priv *priv)
+{
+	if (!priv->reg_xceiver)
+		return 0;
+
+	return regulator_enable(priv->reg_xceiver);
+}
+
+static inline int
+mcp25xxfd_transceiver_disable(const struct mcp25xxfd_priv *priv)
+{
+	if (!priv->reg_xceiver)
+		return 0;
+
+	return regulator_disable(priv->reg_xceiver);
+}
+
+static int mcp25xxfd_clks_and_vdd_enable(const struct mcp25xxfd_priv *priv)
+{
+	int err;
+
+	err = clk_prepare_enable(priv->clk);
+	if (err)
+		return err;
+
+	err = mcp25xxfd_vdd_enable(priv);
+	if (err)
+		clk_disable_unprepare(priv->clk);
+
+	/* Wait for oscillator stabilisation time after power up */
+	usleep_range(MCP25XXFD_OSC_STAB_SLEEP_US,
+		     2 * MCP25XXFD_OSC_STAB_SLEEP_US);
+
+	return err;
+}
+
+static int mcp25xxfd_clks_and_vdd_disable(const struct mcp25xxfd_priv *priv)
+{
+	int err;
+
+	err = mcp25xxfd_vdd_disable(priv);
+	if (err)
+		return err;
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static inline u8
+mcp25xxfd_cmd_prepare_write_reg(const struct mcp25xxfd_priv *priv,
+				union mcp25xxfd_write_reg_buf *write_reg_buf,
+				const u16 reg, const u32 mask, const u32 val)
+{
+	u8 first_byte, last_byte, len;
+	u8 *data;
+	__le32 val_le32;
+
+	first_byte = mcp25xxfd_first_byte_set(mask);
+	last_byte = mcp25xxfd_last_byte_set(mask);
+	len = last_byte - first_byte + 1;
+
+	data = mcp25xxfd_spi_cmd_write(priv, write_reg_buf, reg + first_byte);
+	val_le32 = cpu_to_le32(val >> BITS_PER_BYTE * first_byte);
+	memcpy(data, &val_le32, len);
+
+	if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_REG) {
+		u16 crc;
+
+		mcp25xxfd_spi_cmd_crc_set_len_in_reg(&write_reg_buf->crc.cmd,
+						     len);
+		/* CRC */
+		len += sizeof(write_reg_buf->crc.cmd);
+		crc = mcp25xxfd_crc16_compute(&write_reg_buf->crc, len);
+		put_unaligned_be16(crc, (void *)write_reg_buf + len);
+
+		/* Total length */
+		len += sizeof(write_reg_buf->crc.crc);
+	} else {
+		len += sizeof(write_reg_buf->nocrc.cmd);
+	}
+
+	return len;
+}
+
+static inline int
+mcp25xxfd_tef_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+				 u8 *tef_tail)
+{
+	u32 tef_ua;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_TEFUA, &tef_ua);
+	if (err)
+		return err;
+
+	*tef_tail = tef_ua / sizeof(struct mcp25xxfd_hw_tef_obj);
+
+	return 0;
+}
+
+static inline int
+mcp25xxfd_tx_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+				u8 *tx_tail)
+{
+	u32 fifo_sta;
+	int err;
+
+	err = regmap_read(priv->map_reg,
+			  MCP25XXFD_REG_FIFOSTA(MCP25XXFD_TX_FIFO),
+			  &fifo_sta);
+	if (err)
+		return err;
+
+	*tx_tail = FIELD_GET(MCP25XXFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+	return 0;
+}
+
+static inline int
+mcp25xxfd_rx_head_get_from_chip(const struct mcp25xxfd_priv *priv,
+				const struct mcp25xxfd_rx_ring *ring,
+				u8 *rx_head)
+{
+	u32 fifo_sta;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_FIFOSTA(ring->fifo_nr),
+			  &fifo_sta);
+	if (err)
+		return err;
+
+	*rx_head = FIELD_GET(MCP25XXFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+	return 0;
+}
+
+static inline int
+mcp25xxfd_rx_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+				const struct mcp25xxfd_rx_ring *ring,
+				u8 *rx_tail)
+{
+	u32 fifo_ua;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_FIFOUA(ring->fifo_nr),
+			  &fifo_ua);
+	if (err)
+		return err;
+
+	fifo_ua -= ring->base - MCP25XXFD_RAM_START;
+	*rx_tail = fifo_ua / ring->obj_size;
+
+	return 0;
+}
+
+static void
+mcp25xxfd_tx_ring_init_tx_obj(const struct mcp25xxfd_priv *priv,
+			      const struct mcp25xxfd_tx_ring *ring,
+			      struct mcp25xxfd_tx_obj *tx_obj,
+			      const u8 rts_buf_len,
+			      const u8 n)
+{
+	struct spi_transfer *xfer;
+	u16 addr;
+
+	/* FIFO load */
+	addr = mcp25xxfd_get_tx_obj_addr(ring, n);
+	if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX)
+		mcp25xxfd_spi_cmd_write_crc_set_addr(&tx_obj->buf.crc.cmd,
+						     addr);
+	else
+		mcp25xxfd_spi_cmd_write_nocrc(&tx_obj->buf.nocrc.cmd,
+					      addr);
+
+	xfer = &tx_obj->xfer[0];
+	xfer->tx_buf = &tx_obj->buf;
+	xfer->len = 0;	/* actual len is assigned on the fly */
+	xfer->cs_change = 1;
+	xfer->cs_change_delay.value = 0;
+	xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
+
+	/* FIFO request to send */
+	xfer = &tx_obj->xfer[1];
+	xfer->tx_buf = &ring->rts_buf;
+	xfer->len = rts_buf_len;
+
+	/* SPI message */
+	spi_message_init_with_transfers(&tx_obj->msg, tx_obj->xfer,
+					ARRAY_SIZE(tx_obj->xfer));
+}
+
+static void mcp25xxfd_ring_init(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_tx_ring *tx_ring;
+	struct mcp25xxfd_rx_ring *rx_ring, *prev_rx_ring = NULL;
+	struct mcp25xxfd_tx_obj *tx_obj;
+	u32 val;
+	u16 addr;
+	u8 len;
+	int i;
+
+	/* TEF */
+	priv->tef.head = 0;
+	priv->tef.tail = 0;
+
+	/* TX */
+	tx_ring = priv->tx;
+	tx_ring->head = 0;
+	tx_ring->tail = 0;
+	tx_ring->base = mcp25xxfd_get_tef_obj_addr(tx_ring->obj_num);
+
+	/* FIFO request to send */
+	addr = MCP25XXFD_REG_FIFOCON(MCP25XXFD_TX_FIFO);
+	val = MCP25XXFD_REG_FIFOCON_TXREQ | MCP25XXFD_REG_FIFOCON_UINC;
+	len = mcp25xxfd_cmd_prepare_write_reg(priv, &tx_ring->rts_buf,
+					      addr, val, val);
+
+	mcp25xxfd_for_each_tx_obj(tx_ring, tx_obj, i)
+		mcp25xxfd_tx_ring_init_tx_obj(priv, tx_ring, tx_obj, len, i);
+
+	/* RX */
+	mcp25xxfd_for_each_rx_ring(priv, rx_ring, i) {
+		rx_ring->head = 0;
+		rx_ring->tail = 0;
+		rx_ring->nr = i;
+		rx_ring->fifo_nr = MCP25XXFD_RX_FIFO(i);
+
+		if (!prev_rx_ring)
+			rx_ring->base =
+				mcp25xxfd_get_tx_obj_addr(tx_ring,
+							  tx_ring->obj_num);
+		else
+			rx_ring->base = prev_rx_ring->base +
+				prev_rx_ring->obj_size *
+				prev_rx_ring->obj_num;
+
+		prev_rx_ring = rx_ring;
+	}
+}
+
+static void mcp25xxfd_ring_free(struct mcp25xxfd_priv *priv)
+{
+	int i;
+
+	for (i = ARRAY_SIZE(priv->rx) - 1; i > 0; i--) {
+		kfree(priv->rx[i]);
+		priv->rx[i] = NULL;
+	}
+}
+
+static int mcp25xxfd_ring_alloc(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_tx_ring *tx_ring;
+	struct mcp25xxfd_rx_ring *rx_ring;
+	int tef_obj_size, tx_obj_size, rx_obj_size;
+	int tx_obj_num;
+	int ram_free, i;
+
+	tef_obj_size = sizeof(struct mcp25xxfd_hw_tef_obj);
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		tx_obj_num = MCP25XXFD_TX_OBJ_NUM_CANFD;
+		tx_obj_size = sizeof(struct mcp25xxfd_hw_tx_obj_canfd);
+		rx_obj_size = sizeof(struct mcp25xxfd_hw_rx_obj_canfd);
+	} else {
+		tx_obj_num = MCP25XXFD_TX_OBJ_NUM_CAN;
+		tx_obj_size = sizeof(struct mcp25xxfd_hw_tx_obj_can);
+		rx_obj_size = sizeof(struct mcp25xxfd_hw_rx_obj_can);
+	}
+
+	tx_ring = priv->tx;
+	tx_ring->obj_num = tx_obj_num;
+	tx_ring->obj_size = tx_obj_size;
+
+	ram_free = MCP25XXFD_RAM_SIZE - tx_obj_num *
+		(tef_obj_size + tx_obj_size);
+
+	for (i = 0;
+	     i < ARRAY_SIZE(priv->rx) && ram_free >= rx_obj_size;
+	     i++) {
+		int rx_obj_num;
+
+		rx_obj_num = ram_free / rx_obj_size;
+		rx_obj_num = min(1 << (fls(rx_obj_num) - 1), 32);
+
+		rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
+				  GFP_KERNEL);
+		if (!rx_ring) {
+			mcp25xxfd_ring_free(priv);
+			return -ENOMEM;
+		}
+		rx_ring->obj_num = rx_obj_num;
+		rx_ring->obj_size = rx_obj_size;
+		priv->rx[i] = rx_ring;
+
+		ram_free -= rx_ring->obj_num * rx_ring->obj_size;
+	}
+	priv->rx_ring_num = i;
+
+	netdev_dbg(priv->ndev,
+		   "FIFO setup: TEF: %d*%d bytes = %d bytes, TX: %d*%d bytes = %d bytes\n",
+		   tx_obj_num, tef_obj_size, tef_obj_size * tx_obj_num,
+		   tx_obj_num, tx_obj_size, tx_obj_size * tx_obj_num);
+
+	mcp25xxfd_for_each_rx_ring(priv, rx_ring, i) {
+		netdev_dbg(priv->ndev,
+			   "FIFO setup: RX-%d: %d*%d bytes = %d bytes\n",
+			   i, rx_ring->obj_num, rx_ring->obj_size,
+			   rx_ring->obj_size * rx_ring->obj_num);
+	}
+
+	netdev_dbg(priv->ndev,
+		   "FIFO setup: free: %d bytes\n",
+		   ram_free);
+
+	return 0;
+}
+
+static inline int
+mcp25xxfd_chip_get_mode(const struct mcp25xxfd_priv *priv, u8 *mode)
+{
+	u32 val;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_CON, &val);
+	if (err)
+		return err;
+
+	*mode = FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK, val);
+
+	return 0;
+}
+
+static int
+__mcp25xxfd_chip_set_mode(const struct mcp25xxfd_priv *priv,
+			  const u8 mode_req, bool nowait)
+{
+	u32 con, con_reqop;
+	int err;
+
+	con_reqop = FIELD_PREP(MCP25XXFD_REG_CON_REQOP_MASK, mode_req);
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_CON,
+				 MCP25XXFD_REG_CON_REQOP_MASK, con_reqop);
+	if (err)
+		return err;
+
+	if (mode_req == MCP25XXFD_REG_CON_MODE_SLEEP || nowait)
+		return 0;
+
+	err = regmap_read_poll_timeout(priv->map_reg, MCP25XXFD_REG_CON, con,
+				       FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK,
+						 con) == mode_req,
+				       MCP25XXFD_POLL_SLEEP_US,
+				       MCP25XXFD_POLL_TIMEOUT_US);
+	if (err) {
+		u8 mode = FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK, con);
+
+		netdev_err(priv->ndev,
+			   "Controller failed to enter mode %s Mode (%u) and stays in %s Mode (%u).\n",
+			   mcp25xxfd_get_mode_str(mode_req), mode_req,
+			   mcp25xxfd_get_mode_str(mode), mode);
+		return err;
+	}
+
+	return 0;
+}
+
+static inline int
+mcp25xxfd_chip_set_mode(const struct mcp25xxfd_priv *priv,
+			const u8 mode_req)
+{
+	return __mcp25xxfd_chip_set_mode(priv, mode_req, false);
+}
+
+static inline int
+mcp25xxfd_chip_set_mode_nowait(const struct mcp25xxfd_priv *priv,
+			       const u8 mode_req)
+{
+	return __mcp25xxfd_chip_set_mode(priv, mode_req, true);
+}
+
+static inline bool mcp25xxfd_osc_invalid(u32 reg)
+{
+	return reg == 0x0 || reg == 0xffffffff;
+}
+
+static int mcp25xxfd_chip_clock_enable(const struct mcp25xxfd_priv *priv)
+{
+	u32 osc, osc_reference, osc_mask;
+	int err;
+
+	/* Set Power On Defaults for "Clock Output Divisor" and remove
+	 * "Oscillator Disable" bit.
+	 */
+	osc = FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+			 MCP25XXFD_REG_OSC_CLKODIV_10);
+	osc_reference = MCP25XXFD_REG_OSC_OSCRDY;
+	osc_mask = MCP25XXFD_REG_OSC_OSCRDY | MCP25XXFD_REG_OSC_PLLRDY;
+
+	/* Note:
+	 *
+	 * If the controller is in Sleep Mode the following write only
+	 * removes the "Oscillator Disable" bit and powers it up. All
+	 * other bits are unaffected.
+	 */
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_OSC, osc);
+	if (err)
+		return err;
+
+	/* Wait for "Oscillator Ready" bit */
+	err = regmap_read_poll_timeout(priv->map_reg, MCP25XXFD_REG_OSC, osc,
+				       (osc & osc_mask) == osc_reference,
+				       MCP25XXFD_OSC_STAB_SLEEP_US,
+				       MCP25XXFD_OSC_STAB_TIMEOUT_US);
+	if (mcp25xxfd_osc_invalid(osc)) {
+		netdev_err(priv->ndev,
+			   "Failed to detect %s (osc=0x%08x).\n",
+			   mcp25xxfd_get_model_str(priv), osc);
+		return -ENODEV;
+	} else if (err == -ETIMEDOUT) {
+		netdev_err(priv->ndev,
+			   "Timeout waiting for Oscillator Ready (osc=0x%08x, osc_reference=0x%08x)\n",
+			   osc, osc_reference);
+		return -ETIMEDOUT;
+	} else if (err) {
+		return err;
+	}
+
+	return 0;
+}
+
+static int mcp25xxfd_chip_softreset_do(const struct mcp25xxfd_priv *priv)
+{
+	const __be16 cmd = mcp25xxfd_cmd_reset();
+	int err;
+
+	/* The Set Mode and SPI Reset command only seems to works if
+	 * the controller is not in Sleep Mode.
+	 */
+	err = mcp25xxfd_chip_clock_enable(priv);
+	if (err)
+		return err;
+
+	err = mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_CONFIG);
+	if (err)
+		return err;
+
+	/* spi_write_then_read() works with non DMA-safe buffers */
+	return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
+}
+
+static int mcp25xxfd_chip_softreset_check(const struct mcp25xxfd_priv *priv)
+{
+	u32 osc, osc_reference;
+	u8 mode;
+	int err;
+
+	err = mcp25xxfd_chip_get_mode(priv, &mode);
+	if (err)
+		return err;
+
+	if (mode != MCP25XXFD_REG_CON_MODE_CONFIG) {
+		netdev_info(priv->ndev,
+			    "Controller not in Config Mode after reset, but in %s Mode (%u).\n",
+			    mcp25xxfd_get_mode_str(mode), mode);
+		return -ETIMEDOUT;
+	}
+
+	osc_reference = MCP25XXFD_REG_OSC_OSCRDY |
+		FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+			   MCP25XXFD_REG_OSC_CLKODIV_10);
+
+	/* check reset defaults of OSC reg */
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_OSC, &osc);
+	if (err)
+		return err;
+
+	if (osc != osc_reference) {
+		netdev_info(priv->ndev,
+			    "Controller failed to reset. osc=0x%08x, reference value=0x%08x\n",
+			    osc, osc_reference);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int mcp25xxfd_chip_softreset(const struct mcp25xxfd_priv *priv)
+{
+	int err, i;
+
+	for (i = 0; i < MCP25XXFD_SOFTRESET_RETRIES_MAX; i++) {
+		if (i)
+			netdev_info(priv->ndev,
+				    "Retrying to reset Controller.\n");
+
+		err = mcp25xxfd_chip_softreset_do(priv);
+		if (err == -ETIMEDOUT)
+			continue;
+		if (err)
+			return err;
+
+		err = mcp25xxfd_chip_softreset_check(priv);
+		if (err == -ETIMEDOUT)
+			continue;
+		if (err)
+			return err;
+
+		return 0;
+	}
+
+	if (err)
+		return err;
+
+	return -ETIMEDOUT;
+}
+
+static int mcp25xxfd_chip_clock_init(const struct mcp25xxfd_priv *priv)
+{
+	u32 osc;
+	int err;
+
+	/* Activate Low Power Mode on Oscillator Disable. This only
+	 * works on the MCP2518FD. The MCP2517FD will go into normal
+	 * Sleep Mode instead.
+	 */
+	osc = MCP25XXFD_REG_OSC_LPMEN |
+		FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+			   MCP25XXFD_REG_OSC_CLKODIV_10);
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_OSC, osc);
+	if (err)
+		return err;
+
+	/* Set Time Base Counter Prescaler to 1.
+	 *
+	 * This means an overflow of the 32 bit Time Base Counter
+	 * register at 40 MHz every 107 seconds.
+	 */
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_TSCON,
+			    MCP25XXFD_REG_TSCON_TBCEN);
+}
+
+static int mcp25xxfd_set_bittiming(const struct mcp25xxfd_priv *priv)
+{
+	const struct can_bittiming *bt = &priv->can.bittiming;
+	const struct can_bittiming *dbt = &priv->can.data_bittiming;
+	u32 val = 0;
+	s8 tdco;
+	int err;
+
+	/* CAN Control Register
+	 *
+	 * - no transmit bandwidth sharing
+	 * - config mode
+	 * - disable transmit queue
+	 * - store in transmit FIFO event
+	 * - transition to restricted operation mode on system error
+	 * - ESI is transmitted recessive when ESI of message is high or
+	 *   CAN controller error passive
+	 * - restricted retransmission attempts,
+	 *   use TQXCON_TXAT and FIFOCON_TXAT
+	 * - wake-up filter bits T11FILTER
+	 * - use CAN bus line filter for wakeup
+	 * - protocol exception is treated as a form error
+	 * - Do not compare data bytes
+	 */
+	val = FIELD_PREP(MCP25XXFD_REG_CON_REQOP_MASK,
+			 MCP25XXFD_REG_CON_MODE_CONFIG) |
+		MCP25XXFD_REG_CON_STEF |
+		MCP25XXFD_REG_CON_ESIGM |
+		MCP25XXFD_REG_CON_RTXAT |
+		FIELD_PREP(MCP25XXFD_REG_CON_WFT_MASK,
+			   MCP25XXFD_REG_CON_WFT_T11FILTER) |
+		MCP25XXFD_REG_CON_WAKFIL |
+		MCP25XXFD_REG_CON_PXEDIS;
+
+	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
+		val |= MCP25XXFD_REG_CON_ISOCRCEN;
+
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_CON, val);
+	if (err)
+		return err;
+
+	/* Nominal Bit Time */
+	val = FIELD_PREP(MCP25XXFD_REG_NBTCFG_BRP_MASK, bt->brp - 1) |
+		FIELD_PREP(MCP25XXFD_REG_NBTCFG_TSEG1_MASK,
+			   bt->prop_seg + bt->phase_seg1 - 1) |
+		FIELD_PREP(MCP25XXFD_REG_NBTCFG_TSEG2_MASK,
+			   bt->phase_seg2 - 1) |
+		FIELD_PREP(MCP25XXFD_REG_NBTCFG_SJW_MASK, bt->sjw - 1);
+
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_NBTCFG, val);
+	if (err)
+		return err;
+
+	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
+		return 0;
+
+	/* Data Bit Time */
+	val = FIELD_PREP(MCP25XXFD_REG_DBTCFG_BRP_MASK, dbt->brp - 1) |
+		FIELD_PREP(MCP25XXFD_REG_DBTCFG_TSEG1_MASK,
+			   dbt->prop_seg + dbt->phase_seg1 - 1) |
+		FIELD_PREP(MCP25XXFD_REG_DBTCFG_TSEG2_MASK,
+			   dbt->phase_seg2 - 1) |
+		FIELD_PREP(MCP25XXFD_REG_DBTCFG_SJW_MASK, dbt->sjw - 1);
+
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_DBTCFG, val);
+	if (err)
+		return err;
+
+	/* Transmitter Delay Compensation */
+	tdco = clamp_t(int, dbt->brp * (dbt->prop_seg + dbt->phase_seg1),
+		       -64, 63);
+	val = FIELD_PREP(MCP25XXFD_REG_TDC_TDCMOD_MASK,
+			 MCP25XXFD_REG_TDC_TDCMOD_AUTO) |
+		FIELD_PREP(MCP25XXFD_REG_TDC_TDCO_MASK, tdco);
+
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_TDC, val);
+}
+
+static int mcp25xxfd_chip_rx_int_enable(const struct mcp25xxfd_priv *priv)
+{
+	u32 val;
+
+	if (!priv->rx_int)
+		return 0;
+
+	/* Configure GPIOs:
+	 * - PIN0: GPIO Input
+	 * - PIN1: GPIO Input/RX Interrupt
+	 *
+	 * PIN1 must be Input, otherwise there is a glitch on the
+	 * rx-INT line. It happens between setting the PIN as output
+	 * (in the first byte of the SPI transfer) and configuring the
+	 * PIN as interrupt (in the last byte of the SPI transfer).
+	 */
+	val = MCP25XXFD_REG_IOCON_PM0 | MCP25XXFD_REG_IOCON_TRIS1 |
+		MCP25XXFD_REG_IOCON_TRIS0;
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_IOCON, val);
+}
+
+static int mcp25xxfd_chip_rx_int_disable(const struct mcp25xxfd_priv *priv)
+{
+	u32 val;
+
+	if (!priv->rx_int)
+		return 0;
+
+	/* Configure GPIOs:
+	 * - PIN0: GPIO Input
+	 * - PIN1: GPIO Input
+	 */
+	val = MCP25XXFD_REG_IOCON_PM1 | MCP25XXFD_REG_IOCON_PM0 |
+		MCP25XXFD_REG_IOCON_TRIS1 | MCP25XXFD_REG_IOCON_TRIS0;
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_IOCON, val);
+}
+
+static int
+mcp25xxfd_chip_rx_fifo_init_one(const struct mcp25xxfd_priv *priv,
+				const struct mcp25xxfd_rx_ring *ring)
+{
+	u32 fifo_con;
+
+	/* Enable RXOVIE on _all_ RX FIFOs, not just the last one.
+	 *
+	 * FIFOs hit by a RX MAB overflow and RXOVIE enabled will
+	 * generate a RXOVIF, use this to properly detect RX MAB
+	 * overflows.
+	 */
+	fifo_con = FIELD_PREP(MCP25XXFD_REG_FIFOCON_FSIZE_MASK,
+			      ring->obj_num - 1) |
+		MCP25XXFD_REG_FIFOCON_RXTSEN |
+		MCP25XXFD_REG_FIFOCON_RXOVIE |
+		MCP25XXFD_REG_FIFOCON_TFNRFNIE;
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		fifo_con |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+				       MCP25XXFD_REG_FIFOCON_PLSIZE_64);
+	else
+		fifo_con |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+				       MCP25XXFD_REG_FIFOCON_PLSIZE_8);
+
+	return regmap_write(priv->map_reg,
+			    MCP25XXFD_REG_FIFOCON(ring->fifo_nr), fifo_con);
+}
+
+static int
+mcp25xxfd_chip_rx_filter_init_one(const struct mcp25xxfd_priv *priv,
+				  const struct mcp25xxfd_rx_ring *ring)
+{
+	u32 fltcon;
+
+	fltcon = MCP25XXFD_REG_FLTCON_FLTEN(ring->nr) |
+		MCP25XXFD_REG_FLTCON_FBP(ring->nr, ring->fifo_nr);
+
+	return regmap_update_bits(priv->map_reg,
+				  MCP25XXFD_REG_FLTCON(ring->nr >> 2),
+				  MCP25XXFD_REG_FLTCON_FLT_MASK(ring->nr),
+				  fltcon);
+}
+
+static int mcp25xxfd_chip_fifo_init(const struct mcp25xxfd_priv *priv)
+{
+	const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	const struct mcp25xxfd_rx_ring *rx_ring;
+	u32 val;
+	int err, n;
+
+	/* TEF */
+	val = FIELD_PREP(MCP25XXFD_REG_TEFCON_FSIZE_MASK,
+			 tx_ring->obj_num - 1) |
+		MCP25XXFD_REG_TEFCON_TEFTSEN |
+		MCP25XXFD_REG_TEFCON_TEFOVIE |
+		MCP25XXFD_REG_TEFCON_TEFNEIE;
+
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_TEFCON, val);
+	if (err)
+		return err;
+
+	/* FIFO 1 - TX */
+	val = FIELD_PREP(MCP25XXFD_REG_FIFOCON_FSIZE_MASK,
+			 tx_ring->obj_num - 1) |
+		MCP25XXFD_REG_FIFOCON_TXEN |
+		MCP25XXFD_REG_FIFOCON_TXATIE;
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+				  MCP25XXFD_REG_FIFOCON_PLSIZE_64);
+	else
+		val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+				  MCP25XXFD_REG_FIFOCON_PLSIZE_8);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+		val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_TXAT_MASK,
+				  MCP25XXFD_REG_FIFOCON_TXAT_ONE_SHOT);
+	else
+		val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_TXAT_MASK,
+				  MCP25XXFD_REG_FIFOCON_TXAT_UNLIMITED);
+
+	err = regmap_write(priv->map_reg,
+			   MCP25XXFD_REG_FIFOCON(MCP25XXFD_TX_FIFO),
+			   val);
+	if (err)
+		return err;
+
+	/* RX FIFOs */
+	mcp25xxfd_for_each_rx_ring(priv, rx_ring, n) {
+		err = mcp25xxfd_chip_rx_fifo_init_one(priv, rx_ring);
+		if (err)
+			return err;
+
+		err = mcp25xxfd_chip_rx_filter_init_one(priv, rx_ring);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int mcp25xxfd_chip_ecc_init(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_ecc *ecc = &priv->ecc;
+	void *ram;
+	u32 val = 0;
+	int err;
+
+	ecc->ecc_stat = 0;
+
+	if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_ECC)
+		val = MCP25XXFD_REG_ECCCON_ECCEN;
+
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON,
+				 MCP25XXFD_REG_ECCCON_ECCEN, val);
+	if (err)
+		return err;
+
+	ram = kzalloc(MCP25XXFD_RAM_SIZE, GFP_KERNEL);
+	if (!ram)
+		return -ENOMEM;
+
+	err = regmap_raw_write(priv->map_reg, MCP25XXFD_RAM_START, ram,
+			       MCP25XXFD_RAM_SIZE);
+	kfree(ram);
+
+	return err;
+}
+
+static inline void mcp25xxfd_ecc_tefif_successful(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_ecc *ecc = &priv->ecc;
+
+	ecc->ecc_stat = 0;
+}
+
+static u8 mcp25xxfd_get_normal_mode(const struct mcp25xxfd_priv *priv)
+{
+	u8 mode;
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		mode = MCP25XXFD_REG_CON_MODE_MIXED;
+	else
+		mode = MCP25XXFD_REG_CON_MODE_CAN2_0;
+
+	return mode;
+}
+
+static int
+__mcp25xxfd_chip_set_normal_mode(const struct mcp25xxfd_priv *priv,
+				 bool nowait)
+{
+	u8 mode;
+
+	mode = mcp25xxfd_get_normal_mode(priv);
+
+	return __mcp25xxfd_chip_set_mode(priv, mode, nowait);
+}
+
+static inline int
+mcp25xxfd_chip_set_normal_mode(const struct mcp25xxfd_priv *priv)
+{
+	return __mcp25xxfd_chip_set_normal_mode(priv, false);
+}
+
+static inline int
+mcp25xxfd_chip_set_normal_mode_nowait(const struct mcp25xxfd_priv *priv)
+{
+	return __mcp25xxfd_chip_set_normal_mode(priv, true);
+}
+
+static int mcp25xxfd_chip_interrupts_enable(const struct mcp25xxfd_priv *priv)
+{
+	u32 val;
+	int err;
+
+	val = MCP25XXFD_REG_CRC_FERRIE | MCP25XXFD_REG_CRC_CRCERRIE;
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_CRC, val);
+	if (err)
+		return err;
+
+	val = MCP25XXFD_REG_ECCCON_DEDIE | MCP25XXFD_REG_ECCCON_SECIE;
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON, val, val);
+	if (err)
+		return err;
+
+	val = MCP25XXFD_REG_INT_CERRIE |
+		MCP25XXFD_REG_INT_SERRIE |
+		MCP25XXFD_REG_INT_RXOVIE |
+		MCP25XXFD_REG_INT_TXATIE |
+		MCP25XXFD_REG_INT_SPICRCIE |
+		MCP25XXFD_REG_INT_ECCIE |
+		MCP25XXFD_REG_INT_TEFIE |
+		MCP25XXFD_REG_INT_MODIE |
+		MCP25XXFD_REG_INT_RXIE;
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+		val |= MCP25XXFD_REG_INT_IVMIE;
+
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_INT, val);
+}
+
+static int mcp25xxfd_chip_interrupts_disable(const struct mcp25xxfd_priv *priv)
+{
+	int err;
+	u32 mask;
+
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_INT, 0);
+	if (err)
+		return err;
+
+	mask = MCP25XXFD_REG_ECCCON_DEDIE | MCP25XXFD_REG_ECCCON_SECIE;
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON,
+				 mask, 0x0);
+	if (err)
+		return err;
+
+	return regmap_write(priv->map_reg, MCP25XXFD_REG_CRC, 0);
+}
+
+static int mcp25xxfd_chip_stop(struct mcp25xxfd_priv *priv,
+			       const enum can_state state)
+{
+	priv->can.state = state;
+
+	mcp25xxfd_chip_interrupts_disable(priv);
+	mcp25xxfd_chip_rx_int_disable(priv);
+	return mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+}
+
+static int mcp25xxfd_chip_start(struct mcp25xxfd_priv *priv)
+{
+	int err;
+
+	err = mcp25xxfd_chip_softreset(priv);
+	if (err)
+		goto out_chip_stop;
+
+	err = mcp25xxfd_chip_clock_init(priv);
+	if (err)
+		goto out_chip_stop;
+
+	err = mcp25xxfd_set_bittiming(priv);
+	if (err)
+		goto out_chip_stop;
+
+	err = mcp25xxfd_chip_rx_int_enable(priv);
+	if (err)
+		return err;
+
+	err = mcp25xxfd_chip_ecc_init(priv);
+	if (err)
+		goto out_chip_stop;
+
+	mcp25xxfd_ring_init(priv);
+
+	err = mcp25xxfd_chip_fifo_init(priv);
+	if (err)
+		goto out_chip_stop;
+
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	err = mcp25xxfd_chip_set_normal_mode(priv);
+	if (err)
+		goto out_chip_stop;
+
+	return 0;
+
+ out_chip_stop:
+	mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+
+	return err;
+}
+
+static int mcp25xxfd_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+	struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+	int err;
+
+	switch (mode) {
+	case CAN_MODE_START:
+		err = mcp25xxfd_chip_start(priv);
+		if (err)
+			return err;
+
+		err = mcp25xxfd_chip_interrupts_enable(priv);
+		if (err) {
+			mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+			return err;
+		}
+
+		netif_wake_queue(ndev);
+		break;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int __mcp25xxfd_get_berr_counter(const struct net_device *ndev,
+					struct can_berr_counter *bec)
+{
+	const struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+	u32 trec;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_TREC, &trec);
+	if (err)
+		return err;
+
+	if (trec & MCP25XXFD_REG_TREC_TXBO)
+		bec->txerr = 256;
+	else
+		bec->txerr = FIELD_GET(MCP25XXFD_REG_TREC_TEC_MASK, trec);
+	bec->rxerr = FIELD_GET(MCP25XXFD_REG_TREC_REC_MASK, trec);
+
+	return 0;
+}
+
+static int mcp25xxfd_get_berr_counter(const struct net_device *ndev,
+				      struct can_berr_counter *bec)
+{
+	const struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+
+	/* Avoid waking up the controller if the interface is down */
+	if (!(ndev->flags & IFF_UP))
+		return 0;
+
+	/* The controller is powered down during Bus Off, use saved
+	 * bec values.
+	 */
+	if (priv->can.state == CAN_STATE_BUS_OFF) {
+		*bec = priv->bec;
+		return 0;
+	}
+
+	return __mcp25xxfd_get_berr_counter(ndev, bec);
+}
+
+static int mcp25xxfd_check_tef_tail(const struct mcp25xxfd_priv *priv)
+{
+	u8 tef_tail_chip, tef_tail;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY))
+		return 0;
+
+	err = mcp25xxfd_tef_tail_get_from_chip(priv, &tef_tail_chip);
+	if (err)
+		return err;
+
+	tef_tail = mcp25xxfd_get_tef_tail(priv);
+	if (tef_tail_chip != tef_tail) {
+		netdev_err(priv->ndev,
+			   "TEF tail of chip (0x%02x) and ours (0x%08x) inconsistent.\n",
+			   tef_tail_chip, tef_tail);
+		return -EILSEQ;
+	}
+
+	return 0;
+}
+
+static int
+mcp25xxfd_check_rx_tail(const struct mcp25xxfd_priv *priv,
+			const struct mcp25xxfd_rx_ring *ring)
+{
+	u8 rx_tail_chip, rx_tail;
+	int err;
+
+	if (!IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY))
+		return 0;
+
+	err = mcp25xxfd_rx_tail_get_from_chip(priv, ring, &rx_tail_chip);
+	if (err)
+		return err;
+
+	rx_tail = mcp25xxfd_get_rx_tail(ring);
+	if (rx_tail_chip != rx_tail) {
+		netdev_err(priv->ndev,
+			   "RX tail of chip (%d) and ours (%d) inconsistent.\n",
+			   rx_tail_chip, rx_tail);
+		return -EILSEQ;
+	}
+
+	return 0;
+}
+
+static int
+mcp25xxfd_handle_tefif_recover(const struct mcp25xxfd_priv *priv, const u32 seq)
+{
+	const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	u32 tef_sta;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_TEFSTA, &tef_sta);
+	if (err)
+		return err;
+
+	if (tef_sta & MCP25XXFD_REG_TEFSTA_TEFOVIF) {
+		netdev_err(priv->ndev,
+			   "Transmit Event FIFO buffer overflow.\n");
+		return -ENOBUFS;
+	}
+
+	netdev_info(priv->ndev,
+		    "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x)\n",
+		    tef_sta & MCP25XXFD_REG_TEFSTA_TEFFIF ?
+		    "full" : tef_sta & MCP25XXFD_REG_TEFSTA_TEFNEIF ?
+		    "not empty" : "empty",
+		    seq, priv->tef.tail, priv->tef.head, tx_ring->head);
+
+	/* The Sequence Number in the TEF doesn't match our tef_tail. */
+	return -EAGAIN;
+}
+
+static int
+mcp25xxfd_handle_tefif_one(struct mcp25xxfd_priv *priv,
+			   const struct mcp25xxfd_hw_tef_obj *hw_tef_obj)
+{
+	struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	struct net_device_stats *stats = &priv->ndev->stats;
+	u32 seq, seq_masked, tef_tail_masked;
+	int err;
+
+	seq = FIELD_GET(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+			hw_tef_obj->flags);
+
+	/* Use the MCP2517FD mask on the MCP2518FD, too. We only
+	 * compare 7 bits, this should be enough to detect
+	 * net-yet-completed, i.e. old TEF objects.
+	 */
+	seq_masked = seq &
+		field_mask(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+	tef_tail_masked = priv->tef.tail &
+		field_mask(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+	if (seq_masked != tef_tail_masked)
+		return mcp25xxfd_handle_tefif_recover(priv, seq);
+
+	stats->tx_bytes +=
+		can_rx_offload_get_echo_skb(&priv->offload,
+					    mcp25xxfd_get_tef_tail(priv),
+					    hw_tef_obj->ts);
+	stats->tx_packets++;
+
+	/* finally increment the TEF pointer */
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_TEFCON,
+				 GENMASK(15, 8),
+				 MCP25XXFD_REG_TEFCON_UINC);
+	if (err)
+		return err;
+
+	priv->tef.tail++;
+	tx_ring->tail++;
+
+	return mcp25xxfd_check_tef_tail(priv);
+}
+
+static int mcp25xxfd_tef_ring_update(struct mcp25xxfd_priv *priv)
+{
+	const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	unsigned int new_head;
+	u8 chip_tx_tail;
+	int err;
+
+	err = mcp25xxfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+	if (err)
+		return err;
+
+	/* chip_tx_tail, is the next TX-Object send by the HW.
+	 * The new TEF head must be >= the old head, ...
+	 */
+	new_head = round_down(priv->tef.head, tx_ring->obj_num) + chip_tx_tail;
+	if (new_head <= priv->tef.head)
+		new_head += tx_ring->obj_num;
+
+	/* ... but it cannot exceed the TX head. */
+	priv->tef.head = min(new_head, tx_ring->head);
+
+	return mcp25xxfd_check_tef_tail(priv);
+}
+
+static inline int
+mcp25xxfd_tef_obj_read(const struct mcp25xxfd_priv *priv,
+		       struct mcp25xxfd_hw_tef_obj *hw_tef_obj,
+		       const u8 offset, const u8 len)
+{
+	const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+
+	if (IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY) &&
+	    (offset > tx_ring->obj_num ||
+	     len > tx_ring->obj_num ||
+	     offset + len > tx_ring->obj_num)) {
+		netdev_err(priv->ndev,
+			   "Trying to read to many TEF objects (max=%d, offset=%d, len=%d).\n",
+			   tx_ring->obj_num, offset, len);
+		return -ERANGE;
+	}
+
+	return regmap_bulk_read(priv->map_rx,
+				mcp25xxfd_get_tef_obj_addr(offset),
+				hw_tef_obj,
+				sizeof(*hw_tef_obj) / sizeof(u32) * len);
+}
+
+static int mcp25xxfd_handle_tefif(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_hw_tef_obj hw_tef_obj[MCP25XXFD_TX_OBJ_NUM_MAX];
+	u8 tef_tail, len, l;
+	int err, i;
+
+	err = mcp25xxfd_tef_ring_update(priv);
+	if (err)
+		return err;
+
+	tef_tail = mcp25xxfd_get_tef_tail(priv);
+	len = mcp25xxfd_get_tef_len(priv);
+	l = mcp25xxfd_get_tef_linear_len(priv);
+	err = mcp25xxfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
+	if (err)
+		return err;
+
+	if (l < len) {
+		err = mcp25xxfd_tef_obj_read(priv, &hw_tef_obj[l], 0, len - l);
+		if (err)
+			return err;
+	}
+
+	for (i = 0; i < len; i++) {
+		err = mcp25xxfd_handle_tefif_one(priv, &hw_tef_obj[i]);
+		/* -EAGAIN means the Sequence Number in the TEF
+		 * doesn't match our tef_tail. This can happen if we
+		 * read the TEF objects too early. Leave loop let the
+		 * interrupt handler call us again.
+		 */
+		if (err == -EAGAIN)
+			goto out_netif_wake_queue;
+		if (err)
+			return err;
+	}
+
+ out_netif_wake_queue:
+	mcp25xxfd_ecc_tefif_successful(priv);
+
+	if (mcp25xxfd_get_tx_free(priv->tx)) {
+		/* Make sure that anybody stopping the queue after
+		 * this sees the new tx_ring->tail.
+		 */
+		smp_mb();
+		netif_wake_queue(priv->ndev);
+	}
+
+	return 0;
+}
+
+static int
+mcp25xxfd_rx_ring_update(const struct mcp25xxfd_priv *priv,
+			 struct mcp25xxfd_rx_ring *ring)
+{
+	u32 new_head;
+	u8 chip_rx_head;
+	int err;
+
+	err = mcp25xxfd_rx_head_get_from_chip(priv, ring, &chip_rx_head);
+	if (err)
+		return err;
+
+	/* chip_rx_head, is the next RX-Object filled by the HW.
+	 * The new RX head must be >= the old head.
+	 */
+	new_head = round_down(ring->head, ring->obj_num) + chip_rx_head;
+	if (new_head <= ring->head)
+		new_head += ring->obj_num;
+
+	ring->head = new_head;
+
+	return mcp25xxfd_check_rx_tail(priv, ring);
+}
+
+static void
+mcp25xxfd_hw_rx_obj_to_skb(const struct mcp25xxfd_priv *priv,
+			   const struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj,
+			   struct sk_buff *skb)
+{
+	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+	if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_IDE) {
+		u32 sid, eid;
+
+		eid = FIELD_GET(MCP25XXFD_OBJ_ID_EID_MASK, hw_rx_obj->id);
+		sid = FIELD_GET(MCP25XXFD_OBJ_ID_SID_MASK, hw_rx_obj->id);
+
+		cfd->can_id = CAN_EFF_FLAG |
+			FIELD_PREP(MCP25XXFD_REG_FRAME_EFF_EID_MASK, eid) |
+			FIELD_PREP(MCP25XXFD_REG_FRAME_EFF_SID_MASK, sid);
+	} else {
+		cfd->can_id = FIELD_GET(MCP25XXFD_OBJ_ID_SID_MASK,
+					hw_rx_obj->id);
+	}
+
+	/* CANFD */
+	if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_FDF) {
+		u8 dlc;
+
+		if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_ESI)
+			cfd->flags |= CANFD_ESI;
+
+		if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_BRS)
+			cfd->flags |= CANFD_BRS;
+
+		dlc = FIELD_GET(MCP25XXFD_OBJ_FLAGS_DLC, hw_rx_obj->flags);
+		cfd->len = can_dlc2len(get_canfd_dlc(dlc));
+	} else {
+		if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_RTR)
+			cfd->can_id |= CAN_RTR_FLAG;
+
+		cfd->len = get_can_dlc(FIELD_GET(MCP25XXFD_OBJ_FLAGS_DLC,
+						 hw_rx_obj->flags));
+	}
+
+	memcpy(cfd->data, hw_rx_obj->data, cfd->len);
+}
+
+static int
+mcp25xxfd_handle_rxif_one(struct mcp25xxfd_priv *priv,
+			  struct mcp25xxfd_rx_ring *ring,
+			  const struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj)
+{
+	struct net_device_stats *stats = &priv->ndev->stats;
+	struct sk_buff *skb;
+	struct canfd_frame *cfd;
+	int err;
+
+	if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_FDF)
+		skb = alloc_canfd_skb(priv->ndev, &cfd);
+	else
+		skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cfd);
+
+	if (!cfd) {
+		stats->rx_dropped++;
+		return 0;
+	}
+
+	mcp25xxfd_hw_rx_obj_to_skb(priv, hw_rx_obj, skb);
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, hw_rx_obj->ts);
+	if (err)
+		stats->rx_fifo_errors++;
+
+	ring->tail++;
+
+	/* finally increment the RX pointer */
+	return regmap_update_bits(priv->map_reg,
+				  MCP25XXFD_REG_FIFOCON(ring->fifo_nr),
+				  GENMASK(15, 8),
+				  MCP25XXFD_REG_FIFOCON_UINC);
+}
+
+static inline int
+mcp25xxfd_rx_obj_read(const struct mcp25xxfd_priv *priv,
+		      const struct mcp25xxfd_rx_ring *ring,
+		      struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj,
+		      const u8 offset, const u8 len)
+{
+	int err;
+
+	err = regmap_bulk_read(priv->map_rx,
+			       mcp25xxfd_get_rx_obj_addr(ring, offset),
+			       hw_rx_obj,
+			       len * ring->obj_size / sizeof(u32));
+
+	return err;
+}
+
+static int
+mcp25xxfd_handle_rxif_ring(struct mcp25xxfd_priv *priv,
+			   struct mcp25xxfd_rx_ring *ring)
+{
+	struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj = ring->obj;
+	u8 rx_tail, len;
+	int err, i;
+
+	err = mcp25xxfd_rx_ring_update(priv, ring);
+	if (err)
+		return err;
+
+	while ((len = mcp25xxfd_get_rx_linear_len(ring))) {
+		rx_tail = mcp25xxfd_get_rx_tail(ring);
+
+		err = mcp25xxfd_rx_obj_read(priv, ring, hw_rx_obj,
+					    rx_tail, len);
+		if (err)
+			return err;
+
+		for (i = 0; i < len; i++) {
+			err = mcp25xxfd_handle_rxif_one(priv, ring,
+							(void *)hw_rx_obj +
+							i * ring->obj_size);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int mcp25xxfd_handle_rxif(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_rx_ring *ring;
+	int err, n;
+
+	mcp25xxfd_for_each_rx_ring(priv, ring, n) {
+		err = mcp25xxfd_handle_rxif_ring(priv, ring);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static inline int mcp25xxfd_get_timestamp(const struct mcp25xxfd_priv *priv,
+					  u32 *timestamp)
+{
+	return regmap_read(priv->map_reg, MCP25XXFD_REG_TBC, timestamp);
+}
+
+static struct sk_buff *
+mcp25xxfd_alloc_can_err_skb(const struct mcp25xxfd_priv *priv,
+			    struct can_frame **cf, u32 *timestamp)
+{
+	int err;
+
+	err = mcp25xxfd_get_timestamp(priv, timestamp);
+	if (err)
+		return NULL;
+
+	return alloc_can_err_skb(priv->ndev, cf);
+}
+
+static int mcp25xxfd_handle_rxovif(struct mcp25xxfd_priv *priv)
+{
+	struct net_device_stats *stats = &priv->ndev->stats;
+	struct mcp25xxfd_rx_ring *ring;
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	u32 timestamp, rxovif;
+	int err, i;
+
+	stats->rx_over_errors++;
+	stats->rx_errors++;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_RXOVIF, &rxovif);
+	if (err)
+		return err;
+
+	mcp25xxfd_for_each_rx_ring(priv, ring, i) {
+		if (!(rxovif & BIT(ring->fifo_nr)))
+			continue;
+
+		/* If SERRIF is active, there was a RX MAB overflow. */
+		if (priv->regs_status.intf & MCP25XXFD_REG_INT_SERRIF) {
+			netdev_info(priv->ndev,
+				    "RX-%d: MAB overflow detected.\n",
+				    ring->nr);
+		} else {
+			netdev_info(priv->ndev,
+				    "RX-%d: FIFO overflow.\n", ring->nr);
+		}
+
+		err = regmap_update_bits(priv->map_reg,
+					 MCP25XXFD_REG_FIFOSTA(ring->fifo_nr),
+					 MCP25XXFD_REG_FIFOSTA_RXOVIF,
+					 0x0);
+		if (err)
+			return err;
+	}
+
+	skb = mcp25xxfd_alloc_can_err_skb(priv, &cf, &timestamp);
+	if (!skb)
+		return 0;
+
+	cf->can_id |= CAN_ERR_CRTL;
+	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		stats->rx_fifo_errors++;
+
+	return 0;
+}
+
+static int mcp25xxfd_handle_txatif(struct mcp25xxfd_priv *priv)
+{
+	netdev_info(priv->ndev, "%s\n", __func__);
+
+	return 0;
+}
+
+static int mcp25xxfd_handle_ivmif(struct mcp25xxfd_priv *priv)
+{
+	struct net_device_stats *stats = &priv->ndev->stats;
+	u32 bdiag1, timestamp;
+	struct sk_buff *skb;
+	struct can_frame *cf = NULL;
+	int err;
+
+	err = mcp25xxfd_get_timestamp(priv, &timestamp);
+	if (err)
+		return err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_BDIAG1, &bdiag1);
+	if (err)
+		return err;
+
+	/* Write 0s to clear error bits, don't write 1s to non active
+	 * bits, as they will be set.
+	 */
+	err = regmap_write(priv->map_reg, MCP25XXFD_REG_BDIAG1, 0x0);
+	if (err)
+		return err;
+
+	priv->can.can_stats.bus_error++;
+
+	skb = alloc_can_err_skb(priv->ndev, &cf);
+	if (cf)
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+	/* Controller misconfiguration */
+	if (WARN_ON(bdiag1 & MCP25XXFD_REG_BDIAG1_DLCMM))
+		netdev_err(priv->ndev,
+			   "recv'd DLC is larger than PLSIZE of FIFO element.");
+
+	/* RX errors */
+	if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DCRCERR |
+		      MCP25XXFD_REG_BDIAG1_NCRCERR)) {
+		netdev_dbg(priv->ndev, "CRC error\n");
+
+		stats->rx_errors++;
+		if (cf)
+			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+	}
+	if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DSTUFERR |
+		      MCP25XXFD_REG_BDIAG1_NSTUFERR)) {
+		netdev_dbg(priv->ndev, "Stuff error\n");
+
+		stats->rx_errors++;
+		if (cf)
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
+	}
+	if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DFORMERR |
+		      MCP25XXFD_REG_BDIAG1_NFORMERR)) {
+		netdev_dbg(priv->ndev, "Format error\n");
+
+		stats->rx_errors++;
+		if (cf)
+			cf->data[2] |= CAN_ERR_PROT_FORM;
+	}
+
+	/* TX errors */
+	if (bdiag1 & MCP25XXFD_REG_BDIAG1_NACKERR) {
+		netdev_dbg(priv->ndev, "NACK error\n");
+
+		stats->tx_errors++;
+		if (cf) {
+			cf->can_id |= CAN_ERR_ACK;
+			cf->data[2] |= CAN_ERR_PROT_TX;
+		}
+	}
+	if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DBIT1ERR |
+		      MCP25XXFD_REG_BDIAG1_NBIT1ERR)) {
+		netdev_dbg(priv->ndev, "Bit1 error\n");
+
+		stats->tx_errors++;
+		if (cf)
+			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
+	}
+	if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DBIT0ERR |
+		      MCP25XXFD_REG_BDIAG1_NBIT0ERR)) {
+		netdev_dbg(priv->ndev, "Bit0 error\n");
+
+		stats->tx_errors++;
+		if (cf)
+			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
+	}
+
+	if (!cf)
+		return 0;
+
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		stats->rx_fifo_errors++;
+
+	return 0;
+}
+
+static int mcp25xxfd_handle_cerrif(struct mcp25xxfd_priv *priv)
+{
+	struct net_device_stats *stats = &priv->ndev->stats;
+	struct sk_buff *skb;
+	struct can_frame *cf = NULL;
+	enum can_state new_state, rx_state, tx_state;
+	u32 trec, timestamp;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_TREC, &trec);
+	if (err)
+		return err;
+
+	if (trec & MCP25XXFD_REG_TREC_TXBO)
+		tx_state = CAN_STATE_BUS_OFF;
+	else if (trec & MCP25XXFD_REG_TREC_TXBP)
+		tx_state = CAN_STATE_ERROR_PASSIVE;
+	else if (trec & MCP25XXFD_REG_TREC_TXWARN)
+		tx_state = CAN_STATE_ERROR_WARNING;
+	else
+		tx_state = CAN_STATE_ERROR_ACTIVE;
+
+	if (trec & MCP25XXFD_REG_TREC_RXBP)
+		rx_state = CAN_STATE_ERROR_PASSIVE;
+	else if (trec & MCP25XXFD_REG_TREC_RXWARN)
+		rx_state = CAN_STATE_ERROR_WARNING;
+	else
+		rx_state = CAN_STATE_ERROR_ACTIVE;
+
+	new_state = max(tx_state, rx_state);
+	if (new_state == priv->can.state)
+		return 0;
+
+	/* The skb allocation might fail, but can_change_state()
+	 * handles cf == NULL.
+	 */
+	skb = mcp25xxfd_alloc_can_err_skb(priv, &cf, &timestamp);
+	can_change_state(priv->ndev, cf, tx_state, rx_state);
+
+	if (new_state == CAN_STATE_BUS_OFF) {
+		/* As we're going to switch off the chip now, let's
+		 * save the error counters and return them to
+		 * userspace, if do_get_berr_counter() is called while
+		 * the chip is in Bus Off.
+		 */
+		err = __mcp25xxfd_get_berr_counter(priv->ndev, &priv->bec);
+		if (err)
+			return err;
+
+		mcp25xxfd_chip_stop(priv, CAN_STATE_BUS_OFF);
+		can_bus_off(priv->ndev);
+	}
+
+	if (!skb)
+		return 0;
+
+	if (new_state != CAN_STATE_BUS_OFF) {
+		struct can_berr_counter bec;
+
+		err = mcp25xxfd_get_berr_counter(priv->ndev, &bec);
+		if (err)
+			return err;
+		cf->data[6] = bec.txerr;
+		cf->data[7] = bec.rxerr;
+	}
+
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		stats->rx_fifo_errors++;
+
+	return 0;
+}
+
+static int
+mcp25xxfd_handle_modif(const struct mcp25xxfd_priv *priv, bool *set_normal_mode)
+{
+	const u8 mode_reference = mcp25xxfd_get_normal_mode(priv);
+	u8 mode;
+	int err;
+
+	err = mcp25xxfd_chip_get_mode(priv, &mode);
+	if (err)
+		return err;
+
+	if (mode == mode_reference) {
+		netdev_dbg(priv->ndev,
+			   "Controller changed into %s Mode (%u).\n",
+			   mcp25xxfd_get_mode_str(mode), mode);
+		return 0;
+	}
+
+	/* According to MCP2517FD errata DS80000792B 1., during a TX
+	 * MAB underflow, the controller will transition to Restricted
+	 * Operation Mode or Listen Only Mode (depending on SERR2LOM).
+	 *
+	 * However this is not always the case. If SERR2LOM is
+	 * configured for Restricted Operation Mode (SERR2LOM not set)
+	 * the MCP2517FD will sometimes transition to Listen Only Mode
+	 * first. When polling this bit we see that it will transition
+	 * to Restricted Operation Mode shortly after.
+	 */
+	if ((priv->devtype_data.quirks & MCP25XXFD_QUIRK_MAB_NO_WARN) &&
+	    (mode == MCP25XXFD_REG_CON_MODE_RESTRICTED ||
+	     mode == MCP25XXFD_REG_CON_MODE_LISTENONLY))
+		netdev_dbg(priv->ndev,
+			   "Controller changed into %s Mode (%u).\n",
+			   mcp25xxfd_get_mode_str(mode), mode);
+	else
+		netdev_err(priv->ndev,
+			   "Controller changed into %s Mode (%u).\n",
+			   mcp25xxfd_get_mode_str(mode), mode);
+
+	/* After the application requests Normal mode, the Controller
+	 * will automatically attempt to retransmit the message that
+	 * caused the TX MAB underflow.
+	 *
+	 * However, if there is an ECC error in the TX-RAM, we first
+	 * have to reload the tx-object before requesting Normal
+	 * mode. This is done later in mcp25xxfd_handle_eccif().
+	 */
+	if (priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF) {
+		*set_normal_mode = true;
+		return 0;
+	}
+
+	return mcp25xxfd_chip_set_normal_mode_nowait(priv);
+}
+
+static int mcp25xxfd_handle_serrif(struct mcp25xxfd_priv *priv)
+{
+	struct mcp25xxfd_ecc *ecc = &priv->ecc;
+	struct net_device_stats *stats = &priv->ndev->stats;
+	bool handled = false;
+
+	/* TX MAB underflow
+	 *
+	 * According to MCP2517FD Errata DS80000792B 1. a TX MAB
+	 * underflow is indicated by SERRIF and MODIF.
+	 *
+	 * In addition to the effects mentioned in the Errata, there
+	 * are Bus Errors due to the aborted CAN frame, so a IVMIF
+	 * will be seen as well.
+	 *
+	 * Sometimes there is an ECC error in the TX-RAM, which leads
+	 * to a TX MAB underflow.
+	 *
+	 * However, probably due to a race condition, there is no
+	 * associated MODIF pending.
+	 *
+	 * Further, there are situations, where the SERRIF is caused
+	 * by an ECC error in the TX-RAM, but not even the ECCIF is
+	 * set. This only seems to happen _after_ the first occurrence
+	 * of a ECCIF (which is tracked in ecc->cnt).
+	 *
+	 * Treat all as a known system errors..
+	 */
+	if ((priv->regs_status.intf & MCP25XXFD_REG_INT_MODIF &&
+	     priv->regs_status.intf & MCP25XXFD_REG_INT_IVMIF) ||
+	    priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF ||
+	    ecc->cnt) {
+		const char *msg;
+
+		if (priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF ||
+		    ecc->cnt)
+			msg = "TX MAB underflow due to ECC error detected.";
+		else
+			msg = "TX MAB underflow detected.";
+
+		if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_MAB_NO_WARN)
+			netdev_dbg(priv->ndev, "%s\n", msg);
+		else
+			netdev_info(priv->ndev, "%s\n", msg);
+
+		stats->tx_aborted_errors++;
+		stats->tx_errors++;
+		handled = true;
+	}
+
+	/* RX MAB overflow
+	 *
+	 * According to MCP2517FD Errata DS80000792B 1. a RX MAB
+	 * overflow is indicated by SERRIF.
+	 *
+	 * In addition to the effects mentioned in the Errata, (most
+	 * of the times) a RXOVIF is raised, if the FIFO that is being
+	 * received into has the RXOVIE activated (and we have enabled
+	 * RXOVIE on all FIFOs).
+	 *
+	 * Sometimes there is no RXOVIF just a RXIF is pending.
+	 *
+	 * Treat all as a known system errors..
+	 */
+	if (priv->regs_status.intf & MCP25XXFD_REG_INT_RXOVIF ||
+	    priv->regs_status.intf & MCP25XXFD_REG_INT_RXIF) {
+		stats->rx_dropped++;
+		handled = true;
+	}
+
+	if (!handled)
+		netdev_err(priv->ndev,
+			   "Unhandled System Error Interrupt (intf=0x%08x)!\n",
+			   priv->regs_status.intf);
+
+	return 0;
+}
+
+static int
+mcp25xxfd_handle_eccif_recover(struct mcp25xxfd_priv *priv, u8 nr)
+{
+	struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	struct mcp25xxfd_ecc *ecc = &priv->ecc;
+	struct mcp25xxfd_tx_obj *tx_obj;
+	u8 chip_tx_tail, tx_tail, offset;
+	u16 addr;
+	int err;
+
+	addr = FIELD_GET(MCP25XXFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
+
+	err = mcp25xxfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+	if (err)
+		return err;
+
+	tx_tail = mcp25xxfd_get_tx_tail(tx_ring);
+	offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
+
+	/* Bail out if one of the following is met:
+	 * - tx_tail information is inconsistent
+	 * - for mcp2517fd: offset not 0
+	 * - for mcp2518fd: offset not 0 or 1
+	 */
+	if (chip_tx_tail != tx_tail ||
+	    !(offset == 0 || (offset == 1 && mcp25xxfd_is_2518(priv)))) {
+		netdev_err(priv->ndev,
+			   "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
+			   addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
+			   offset);
+		return -EINVAL;
+	}
+
+	netdev_info(priv->ndev,
+		    "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
+		    ecc->ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF ?
+		    "Single" : "Double",
+		    addr, nr, tx_ring->tail, tx_tail, offset);
+
+	/* reload tx_obj into controller RAM ... */
+	tx_obj = &tx_ring->obj[nr];
+	err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
+	if (err)
+		return err;
+
+	/* ... and trigger retransmit */
+	return mcp25xxfd_chip_set_normal_mode(priv);
+}
+
+static int
+mcp25xxfd_handle_eccif(struct mcp25xxfd_priv *priv, bool set_normal_mode)
+{
+	struct mcp25xxfd_ecc *ecc = &priv->ecc;
+	const char *msg;
+	bool in_tx_ram;
+	u32 ecc_stat;
+	u16 addr;
+	u8 nr;
+	int err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_ECCSTAT, &ecc_stat);
+	if (err)
+		return err;
+
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCSTAT,
+				 MCP25XXFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
+	if (err)
+		return err;
+
+	/* Check if ECC error occurred in TX-RAM */
+	addr = FIELD_GET(MCP25XXFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
+	err = mcp25xxfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
+	if (!err)
+		in_tx_ram = true;
+	else if (err == -ENOENT)
+		in_tx_ram = false;
+	else
+		return err;
+
+	if (ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF)
+		msg = "Single ECC Error corrected at address";
+	else if (ecc_stat & MCP25XXFD_REG_ECCSTAT_DEDIF)
+		msg = "Double ECC Error detected at address";
+	else
+		return -EINVAL;
+
+	if (!in_tx_ram) {
+		ecc->ecc_stat = 0;
+
+		if (ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF)
+			netdev_info(priv->ndev, "%s 0x%04x.\n",
+				    msg, addr);
+		else
+			netdev_notice(priv->ndev, "%s 0x%04x.\n",
+				      msg, addr);
+	} else {
+		/* Re-occurring error? */
+		if (ecc->ecc_stat == ecc_stat) {
+			ecc->cnt++;
+		} else {
+			ecc->ecc_stat = ecc_stat;
+			ecc->cnt = 1;
+		}
+
+		netdev_info(priv->ndev,
+			    "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
+			    msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
+
+		if (ecc->cnt >= MCP25XXFD_ECC_CNT_MAX)
+			return mcp25xxfd_handle_eccif_recover(priv, nr);
+	}
+
+	if (set_normal_mode)
+		return mcp25xxfd_chip_set_normal_mode_nowait(priv);
+
+	return 0;
+}
+
+static int mcp25xxfd_handle_spicrcif(struct mcp25xxfd_priv *priv)
+{
+	int err;
+	u32 crc;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_CRC, &crc);
+	if (err)
+		return err;
+
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_CRC,
+				 MCP25XXFD_REG_CRC_IF_MASK,
+				 ~crc);
+	if (err)
+		return err;
+
+	if (crc & MCP25XXFD_REG_CRC_FERRIF)
+		netdev_notice(priv->ndev, "CRC write command format error.\n");
+	else if (crc & MCP25XXFD_REG_CRC_CRCERRIF)
+		netdev_notice(priv->ndev,
+			      "CRC write error detected. CRC=0x%04lx.\n",
+			      FIELD_GET(MCP25XXFD_REG_CRC_MASK, crc));
+
+	return 0;
+}
+
+#define mcp25xxfd_handle(priv, irq, ...) \
+({ \
+	struct mcp25xxfd_priv *_priv = (priv); \
+	int err; \
+\
+	err = mcp25xxfd_handle_##irq(_priv, ## __VA_ARGS__); \
+	if (err) \
+		netdev_err(_priv->ndev, \
+			"IRQ handler mcp25xxfd_handle_%s() returned %d.\n", \
+			__stringify(irq), err); \
+	err; \
+})
+
+static irqreturn_t mcp25xxfd_irq(int irq, void *dev_id)
+{
+	struct mcp25xxfd_priv *priv = dev_id;
+	irqreturn_t handled = IRQ_NONE;
+	int err;
+
+	if (priv->rx_int)
+		do {
+			int rx_pending;
+
+			rx_pending = gpiod_get_value_cansleep(priv->rx_int);
+			if (!rx_pending)
+				break;
+
+			err = mcp25xxfd_handle(priv, rxif);
+			if (err)
+				goto out_fail;
+
+			handled = IRQ_HANDLED;
+		} while (1);
+
+	do {
+		u32 intf_pending, intf_pending_clearable;
+		bool set_normal_mode;
+
+		err = regmap_bulk_read(priv->map_reg, MCP25XXFD_REG_INT,
+				       &priv->regs_status,
+				       sizeof(priv->regs_status) /
+				       sizeof(u32));
+		if (err)
+			goto out_fail;
+
+		intf_pending = FIELD_GET(MCP25XXFD_REG_INT_IF_MASK,
+					 priv->regs_status.intf) &
+			FIELD_GET(MCP25XXFD_REG_INT_IE_MASK,
+				  priv->regs_status.intf);
+
+		if (!(intf_pending))
+			return handled;
+
+		/* Some interrupts must be ACKed in the
+		 * MCP25XXFD_REG_INT register.
+		 * - First ACK then handle, to avoid lost-IRQ race
+		 *   condition on fast re-occurring interrupts.
+		 * - Write "0" to clear active IRQs, "1" to all other,
+		 *   to avoid r/m/w race condition on the
+		 *   MCP25XXFD_REG_INT register.
+		 */
+		intf_pending_clearable = intf_pending &
+			MCP25XXFD_REG_INT_IF_CLEARABLE_MASK;
+		if (intf_pending_clearable) {
+			err = regmap_update_bits(priv->map_reg,
+						 MCP25XXFD_REG_INT,
+						 MCP25XXFD_REG_INT_IF_MASK,
+						 ~intf_pending_clearable);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_MODIF) {
+			err = mcp25xxfd_handle(priv, modif, &set_normal_mode);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_RXIF) {
+			err = mcp25xxfd_handle(priv, rxif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_TEFIF) {
+			err = mcp25xxfd_handle(priv, tefif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_RXOVIF) {
+			err = mcp25xxfd_handle(priv, rxovif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_TXATIF) {
+			err = mcp25xxfd_handle(priv, txatif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_IVMIF) {
+			err = mcp25xxfd_handle(priv, ivmif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_SERRIF) {
+			err = mcp25xxfd_handle(priv, serrif);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_ECCIF) {
+			err = mcp25xxfd_handle(priv, eccif, set_normal_mode);
+			if (err)
+				goto out_fail;
+		}
+
+		if (intf_pending & MCP25XXFD_REG_INT_SPICRCIF) {
+			err = mcp25xxfd_handle(priv, spicrcif);
+			if (err)
+				goto out_fail;
+		}
+
+		/* On the MCP2527FD and MCP2518FD, we don't get a
+		 * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
+		 * ERROR_ACTIVE.
+		 */
+		if (intf_pending & MCP25XXFD_REG_INT_CERRIF ||
+		    priv->can.state > CAN_STATE_ERROR_ACTIVE) {
+			err = mcp25xxfd_handle(priv, cerrif);
+			if (err)
+				goto out_fail;
+
+			/* In Bus Off we completely shut down the
+			 * controller. Every subsequent register read
+			 * will read bogus data, and if
+			 * MCP25XXFD_QUIRK_CRC_REG is enabled the CRC
+			 * check will fail, too. So leave IRQ handler
+			 * directly.
+			 */
+			if (priv->can.state == CAN_STATE_BUS_OFF)
+				return IRQ_HANDLED;
+		}
+
+		handled = IRQ_HANDLED;
+	} while (1);
+
+ out_fail:
+	netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
+		   err, priv->regs_status.intf);
+	mcp25xxfd_chip_interrupts_disable(priv);
+
+	return handled;
+}
+
+static inline struct
+mcp25xxfd_tx_obj *mcp25xxfd_get_tx_obj_next(struct mcp25xxfd_tx_ring *tx_ring)
+{
+	u8 tx_head;
+
+	tx_head = mcp25xxfd_get_tx_head(tx_ring);
+
+	return &tx_ring->obj[tx_head];
+}
+
+static void
+mcp25xxfd_tx_obj_from_skb(const struct mcp25xxfd_priv *priv,
+			  struct mcp25xxfd_tx_obj *tx_obj,
+			  const struct sk_buff *skb,
+			  unsigned int seq)
+{
+	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+	struct mcp25xxfd_hw_tx_obj_raw *hw_tx_obj;
+	union mcp25xxfd_tx_obj_load_buf *load_buf;
+	u8 dlc;
+	u32 id, flags;
+	int offset, len;
+
+	if (cfd->can_id & CAN_EFF_FLAG) {
+		u32 sid, eid;
+
+		sid = FIELD_GET(MCP25XXFD_REG_FRAME_EFF_SID_MASK, cfd->can_id);
+		eid = FIELD_GET(MCP25XXFD_REG_FRAME_EFF_EID_MASK, cfd->can_id);
+
+		id = FIELD_PREP(MCP25XXFD_OBJ_ID_EID_MASK, eid) |
+			FIELD_PREP(MCP25XXFD_OBJ_ID_SID_MASK, sid);
+
+		flags = MCP25XXFD_OBJ_FLAGS_IDE;
+	} else {
+		id = FIELD_PREP(MCP25XXFD_OBJ_ID_SID_MASK, cfd->can_id);
+		flags = 0;
+	}
+
+	/* Use the MCP2518FD mask even on the MCP2517FD. It doesn't
+	 * harm, only the lower 7 bits will be transferred into the
+	 * TEF object.
+	 */
+	dlc = can_len2dlc(cfd->len);
+	flags |= FIELD_PREP(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK, seq) |
+		FIELD_PREP(MCP25XXFD_OBJ_FLAGS_DLC, dlc);
+
+	if (cfd->can_id & CAN_RTR_FLAG)
+		flags |= MCP25XXFD_OBJ_FLAGS_RTR;
+
+	/* CANFD */
+	if (can_is_canfd_skb(skb)) {
+		if (cfd->flags & CANFD_ESI)
+			flags |= MCP25XXFD_OBJ_FLAGS_ESI;
+
+		flags |= MCP25XXFD_OBJ_FLAGS_FDF;
+
+		if (cfd->flags & CANFD_BRS)
+			flags |= MCP25XXFD_OBJ_FLAGS_BRS;
+	}
+
+	load_buf = &tx_obj->buf;
+	if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX)
+		hw_tx_obj = &load_buf->crc.hw_tx_obj;
+	else
+		hw_tx_obj = &load_buf->nocrc.hw_tx_obj;
+
+	put_unaligned_le32(id, &hw_tx_obj->id);
+	put_unaligned_le32(flags, &hw_tx_obj->flags);
+
+	/* Clear data at end of CAN frame */
+	offset = round_down(cfd->len, sizeof(u32));
+	len = round_up(can_dlc2len(dlc), sizeof(u32)) - offset;
+	if (MCP25XXFD_SANITIZE_CAN && len)
+		memset(hw_tx_obj->data + offset, 0x0, len);
+	memcpy(hw_tx_obj->data, cfd->data, cfd->len);
+
+	/* Number of bytes to be written into the RAM of the controller */
+	len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags);
+	if (MCP25XXFD_SANITIZE_CAN)
+		len += round_up(can_dlc2len(dlc), sizeof(u32));
+	else
+		len += round_up(cfd->len, sizeof(u32));
+
+	if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX) {
+		u16 crc;
+
+		mcp25xxfd_spi_cmd_crc_set_len_in_ram(&load_buf->crc.cmd,
+						     len);
+		/* CRC */
+		len += sizeof(load_buf->crc.cmd);
+		crc = mcp25xxfd_crc16_compute(&load_buf->crc, len);
+		put_unaligned_be16(crc, (void *)load_buf + len);
+
+		/* Total length */
+		len += sizeof(load_buf->crc.crc);
+	} else {
+		len += sizeof(load_buf->nocrc.cmd);
+	}
+
+	tx_obj->xfer[0].len = len;
+}
+
+static int mcp25xxfd_tx_obj_write(const struct mcp25xxfd_priv *priv,
+				  struct mcp25xxfd_tx_obj *tx_obj)
+{
+	return spi_async(priv->spi, &tx_obj->msg);
+}
+
+static bool mcp25xxfd_tx_busy(const struct mcp25xxfd_priv *priv,
+			      struct mcp25xxfd_tx_ring *tx_ring)
+{
+	if (mcp25xxfd_get_tx_free(tx_ring) > 0)
+		return false;
+
+	netif_stop_queue(priv->ndev);
+
+	/* Memory barrier before checking tx_free (head and tail) */
+	smp_mb();
+
+	if (mcp25xxfd_get_tx_free(tx_ring) == 0) {
+		netdev_dbg(priv->ndev,
+			   "Stopping tx-queue (tx_head=0x%08x, tx_tail=0x%08x, len=%d).\n",
+			   tx_ring->head, tx_ring->tail,
+			   tx_ring->head - tx_ring->tail);
+
+		return true;
+	}
+
+	netif_start_queue(priv->ndev);
+
+	return false;
+}
+
+static netdev_tx_t mcp25xxfd_start_xmit(struct sk_buff *skb,
+					struct net_device *ndev)
+{
+	struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+	struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+	struct mcp25xxfd_tx_obj *tx_obj;
+	u8 tx_head;
+	int err;
+
+	if (can_dropped_invalid_skb(ndev, skb))
+		return NETDEV_TX_OK;
+
+	if (mcp25xxfd_tx_busy(priv, tx_ring))
+		return NETDEV_TX_BUSY;
+
+	tx_obj = mcp25xxfd_get_tx_obj_next(tx_ring);
+	mcp25xxfd_tx_obj_from_skb(priv, tx_obj, skb, tx_ring->head);
+
+	/* Stop queue if we occupy the complete TX FIFO */
+	tx_head = mcp25xxfd_get_tx_head(tx_ring);
+	tx_ring->head++;
+	if (tx_ring->head - tx_ring->tail >= tx_ring->obj_num)
+		netif_stop_queue(ndev);
+
+	can_put_echo_skb(skb, ndev, tx_head);
+
+	err = mcp25xxfd_tx_obj_write(priv, tx_obj);
+	if (err)
+		goto out_err;
+
+	return NETDEV_TX_OK;
+
+ out_err:
+	netdev_err(priv->ndev, "ERROR in %s: %d\n", __func__, err);
+
+	return NETDEV_TX_OK;
+}
+
+static int mcp25xxfd_open(struct net_device *ndev)
+{
+	struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+	const struct spi_device *spi = priv->spi;
+	int err;
+
+	err = pm_runtime_get_sync(ndev->dev.parent);
+	if (err < 0) {
+		pm_runtime_put_noidle(ndev->dev.parent);
+		return err;
+	}
+
+	err = open_candev(ndev);
+	if (err)
+		goto out_pm_runtime_put;
+
+	err = mcp25xxfd_ring_alloc(priv);
+	if (err)
+		goto out_close_candev;
+
+	err = mcp25xxfd_transceiver_enable(priv);
+	if (err)
+		goto out_mcp25xxfd_ring_free;
+
+	err = mcp25xxfd_chip_start(priv);
+	if (err)
+		goto out_transceiver_disable;
+
+	can_rx_offload_enable(&priv->offload);
+
+	err = request_threaded_irq(spi->irq, NULL, mcp25xxfd_irq,
+				   IRQF_ONESHOT, dev_name(&spi->dev),
+				   priv);
+	if (err)
+		goto out_can_rx_offload_disable;
+
+	err = mcp25xxfd_chip_interrupts_enable(priv);
+	if (err)
+		goto out_free_irq;
+
+	netif_start_queue(ndev);
+
+	return 0;
+
+ out_free_irq:
+	free_irq(spi->irq, priv);
+ out_can_rx_offload_disable:
+	can_rx_offload_disable(&priv->offload);
+ out_transceiver_disable:
+	mcp25xxfd_transceiver_disable(priv);
+ out_mcp25xxfd_ring_free:
+	mcp25xxfd_ring_free(priv);
+ out_close_candev:
+	close_candev(ndev);
+ out_pm_runtime_put:
+	mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+	pm_runtime_put(ndev->dev.parent);
+
+	return err;
+}
+
+static int mcp25xxfd_stop(struct net_device *ndev)
+{
+	struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+
+	netif_stop_queue(ndev);
+	mcp25xxfd_chip_interrupts_disable(priv);
+	free_irq(ndev->irq, priv);
+	can_rx_offload_disable(&priv->offload);
+	mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+	mcp25xxfd_transceiver_disable(priv);
+	mcp25xxfd_ring_free(priv);
+	close_candev(ndev);
+
+	pm_runtime_put(ndev->dev.parent);
+
+	return 0;
+}
+
+static const struct net_device_ops mcp25xxfd_netdev_ops = {
+	.ndo_open = mcp25xxfd_open,
+	.ndo_stop = mcp25xxfd_stop,
+	.ndo_start_xmit	= mcp25xxfd_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
+};
+
+static void
+mcp25xxfd_register_quirks(struct mcp25xxfd_priv *priv)
+{
+	const struct spi_device *spi = priv->spi;
+	const struct spi_controller *ctlr = spi->controller;
+
+	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
+		priv->devtype_data.quirks |= MCP25XXFD_QUIRK_HALF_DUPLEX;
+}
+
+static int mcp25xxfd_register_chip_detect(struct mcp25xxfd_priv *priv)
+{
+	const struct net_device *ndev = priv->ndev;
+	const struct mcp25xxfd_devtype_data *devtype_data;
+	u32 osc;
+	int err;
+
+	/* The OSC_LPMEN is only supported on MCP2518FD, so use it to
+	 * autodetect the model.
+	 */
+	err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_OSC,
+				 MCP25XXFD_REG_OSC_LPMEN,
+				 MCP25XXFD_REG_OSC_LPMEN);
+	if (err)
+		return err;
+
+	err = regmap_read(priv->map_reg, MCP25XXFD_REG_OSC, &osc);
+	if (err)
+		return err;
+
+	if (osc & MCP25XXFD_REG_OSC_LPMEN)
+		devtype_data = &mcp25xxfd_devtype_data_mcp2518fd;
+	else
+		devtype_data = &mcp25xxfd_devtype_data_mcp2517fd;
+
+	if (!mcp25xxfd_is_25XX(priv) &&
+	    priv->devtype_data.model != devtype_data->model) {
+		netdev_info(ndev,
+			    "Detected %s, but firmware specifies a %s. Fixing up.",
+			    __mcp25xxfd_get_model_str(devtype_data->model),
+			    mcp25xxfd_get_model_str(priv));
+	}
+	priv->devtype_data = *devtype_data;
+
+	/* We need to preserve the Half Duplex Quirk. */
+	mcp25xxfd_register_quirks(priv);
+
+	/* Re-init regmap with quirks of detected model. */
+	return mcp25xxfd_regmap_init(priv);
+}
+
+static int mcp25xxfd_register_check_rx_int(struct mcp25xxfd_priv *priv)
+{
+	int err, rx_pending;
+
+	if (!priv->rx_int)
+		return 0;
+
+	err = mcp25xxfd_chip_rx_int_enable(priv);
+	if (err)
+		return err;
+
+	/* Check if RX_INT is properly working. The RX_INT should not
+	 * be active after a softreset.
+	 */
+	rx_pending = gpiod_get_value_cansleep(priv->rx_int);
+
+	err = mcp25xxfd_chip_rx_int_disable(priv);
+	if (err)
+		return err;
+
+	if (!rx_pending)
+		return 0;
+
+	netdev_info(priv->ndev,
+		    "RX_INT active after softreset, disabling RX_INT support.");
+	devm_gpiod_put(&priv->spi->dev, priv->rx_int);
+	priv->rx_int = NULL;
+
+	return 0;
+}
+
+static int
+mcp25xxfd_register_get_dev_id(const struct mcp25xxfd_priv *priv,
+			      u32 *dev_id, u32 *effective_speed_hz)
+{
+	struct mcp25xxfd_map_buf_nocrc *buf_rx;
+	struct mcp25xxfd_map_buf_nocrc *buf_tx;
+	struct spi_transfer xfer[2] = { };
+	int err;
+
+	buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
+	if (!buf_rx)
+		return -ENOMEM;
+
+	buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
+	if (!buf_tx) {
+		err = -ENOMEM;
+		goto out_kfree_buf_rx;
+	}
+
+	xfer[0].tx_buf = buf_tx;
+	xfer[0].len = sizeof(buf_tx->cmd);
+	xfer[1].rx_buf = buf_rx->data;
+	xfer[1].len = sizeof(dev_id);
+
+	mcp25xxfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP25XXFD_REG_DEVID);
+	err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
+	if (err)
+		goto out_kfree_buf_tx;
+
+	*dev_id = be32_to_cpup((__be32 *)buf_rx->data);
+	*effective_speed_hz = xfer->effective_speed_hz;
+
+ out_kfree_buf_tx:
+	kfree(buf_tx);
+ out_kfree_buf_rx:
+	kfree(buf_rx);
+
+	return 0;
+}
+
+#define MCP25XXFD_QUIRK_ACTIVE(quirk) \
+	(priv->devtype_data.quirks & MCP25XXFD_QUIRK_##quirk ? '+' : '-')
+
+static int
+mcp25xxfd_register_done(const struct mcp25xxfd_priv *priv)
+{
+	u32 dev_id, effective_speed_hz;
+	int err;
+
+	err = mcp25xxfd_register_get_dev_id(priv, &dev_id,
+					    &effective_speed_hz);
+	if (err)
+		return err;
+
+	netdev_info(priv->ndev,
+		    "%s rev%lu.%lu (%cRX_INT %cMAB_NO_WARN %cCRC_REG %cCRC_RX %cCRC_TX %cECC %cHD c:%u.%02uMHz m:%u.%02uMHz r:%u.%02uMHz e:%u.%02uMHz) successfully initialized.\n",
+		    mcp25xxfd_get_model_str(priv),
+		    FIELD_GET(MCP25XXFD_REG_DEVID_ID_MASK, dev_id),
+		    FIELD_GET(MCP25XXFD_REG_DEVID_REV_MASK, dev_id),
+		    priv->rx_int ? '+' : '-',
+		    MCP25XXFD_QUIRK_ACTIVE(MAB_NO_WARN),
+		    MCP25XXFD_QUIRK_ACTIVE(CRC_REG),
+		    MCP25XXFD_QUIRK_ACTIVE(CRC_RX),
+		    MCP25XXFD_QUIRK_ACTIVE(CRC_TX),
+		    MCP25XXFD_QUIRK_ACTIVE(ECC),
+		    MCP25XXFD_QUIRK_ACTIVE(HALF_DUPLEX),
+		    priv->can.clock.freq / 1000000,
+		    priv->can.clock.freq % 1000000 / 1000 / 10,
+		    priv->spi_max_speed_hz_orig / 1000000,
+		    priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
+		    priv->spi->max_speed_hz / 1000000,
+		    priv->spi->max_speed_hz % 1000000 / 1000 / 10,
+		    effective_speed_hz / 1000000,
+		    effective_speed_hz % 1000000 / 1000 / 10);
+
+	return 0;
+}
+
+static int mcp25xxfd_register(struct mcp25xxfd_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+	int err;
+
+	err = mcp25xxfd_clks_and_vdd_enable(priv);
+	if (err)
+		return err;
+
+	pm_runtime_get_noresume(ndev->dev.parent);
+	err = pm_runtime_set_active(ndev->dev.parent);
+	if (err)
+		goto out_runtime_put_noidle;
+	pm_runtime_enable(ndev->dev.parent);
+
+	mcp25xxfd_register_quirks(priv);
+
+	err = mcp25xxfd_chip_softreset(priv);
+	if (err == -ENODEV)
+		goto out_runtime_disable;
+	if (err)
+		goto out_chip_set_mode_sleep;
+
+	err = mcp25xxfd_register_chip_detect(priv);
+	if (err)
+		goto out_chip_set_mode_sleep;
+
+	err = mcp25xxfd_register_check_rx_int(priv);
+	if (err)
+		goto out_chip_set_mode_sleep;
+
+	err = register_candev(ndev);
+	if (err)
+		goto out_chip_set_mode_sleep;
+
+	err = mcp25xxfd_register_done(priv);
+	if (err)
+		goto out_unregister_candev;
+
+	/* Put controller into sleep mode and let pm_runtime_put()
+	 * disable the clocks and vdd. If CONFIG_PM is not enabled,
+	 * the clocks and vdd will stay powered.
+	 */
+	err = mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+	if (err)
+		goto out_unregister_candev;
+
+	pm_runtime_put(ndev->dev.parent);
+
+	return 0;
+
+ out_unregister_candev:
+	unregister_candev(ndev);
+ out_chip_set_mode_sleep:
+	mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+ out_runtime_disable:
+	pm_runtime_disable(ndev->dev.parent);
+ out_runtime_put_noidle:
+	pm_runtime_put_noidle(ndev->dev.parent);
+	mcp25xxfd_clks_and_vdd_disable(priv);
+
+	return err;
+}
+
+static inline void mcp25xxfd_unregister(struct mcp25xxfd_priv *priv)
+{
+	struct net_device *ndev	= priv->ndev;
+
+	unregister_candev(ndev);
+
+	pm_runtime_get_sync(ndev->dev.parent);
+	pm_runtime_put_noidle(ndev->dev.parent);
+	mcp25xxfd_clks_and_vdd_disable(priv);
+	pm_runtime_disable(ndev->dev.parent);
+}
+
+static const struct of_device_id mcp25xxfd_of_match[] = {
+	{
+		.compatible = "microchip,mcp2517fd",
+		.data = &mcp25xxfd_devtype_data_mcp2517fd,
+	}, {
+		.compatible = "microchip,mcp2518fd",
+		.data = &mcp25xxfd_devtype_data_mcp2518fd,
+	}, {
+		.compatible = "microchip,mcp25xxfd",
+		.data = &mcp25xxfd_devtype_data_mcp25xxfd,
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(of, mcp25xxfd_of_match);
+
+static const struct spi_device_id mcp25xxfd_id_table[] = {
+	{
+		.name = "mcp2517fd",
+		.driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp2517fd,
+	}, {
+		.name = "mcp2518fd",
+		.driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp2518fd,
+	}, {
+		.name = "mcp25xxfd",
+		.driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp25xxfd,
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(spi, mcp25xxfd_id_table);
+
+static int mcp25xxfd_probe(struct spi_device *spi)
+{
+	const void *match;
+	struct net_device *ndev;
+	struct mcp25xxfd_priv *priv;
+	struct gpio_desc *rx_int;
+	struct regulator *reg_vdd, *reg_xceiver;
+	struct clk *clk;
+	u32 freq;
+	int err;
+
+	rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
+					 GPIOD_IN);
+	if (PTR_ERR(rx_int) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (IS_ERR(rx_int))
+		return PTR_ERR(rx_int);
+
+	reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
+	if (PTR_ERR(reg_vdd) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (PTR_ERR(reg_vdd) == -ENODEV)
+		reg_vdd = NULL;
+	else if (IS_ERR(reg_vdd))
+		return PTR_ERR(reg_vdd);
+
+	reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
+	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (PTR_ERR(reg_xceiver) == -ENODEV)
+		reg_xceiver = NULL;
+	else if (IS_ERR(reg_xceiver))
+		return PTR_ERR(reg_xceiver);
+
+	clk = devm_clk_get(&spi->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&spi->dev, "No Oscillator (clock) defined.\n");
+		return PTR_ERR(clk);
+	}
+	freq = clk_get_rate(clk);
+
+	/* Sanity check */
+	if (freq < MCP25XXFD_SYSCLOCK_HZ_MIN ||
+	    freq > MCP25XXFD_SYSCLOCK_HZ_MAX) {
+		dev_err(&spi->dev,
+			"Oscillator frequency (%u Hz) is too low or high.\n",
+			freq);
+		return -ERANGE;
+	}
+
+	if (freq <= MCP25XXFD_SYSCLOCK_HZ_MAX / MCP25XXFD_OSC_PLL_MULTIPLIER) {
+		dev_err(&spi->dev,
+			"Oscillator frequency (%u Hz) is too low and PLL is not supported.\n",
+			freq);
+		return -ERANGE;
+	}
+
+	ndev = alloc_candev(sizeof(struct mcp25xxfd_priv),
+			    MCP25XXFD_TX_OBJ_NUM_MAX);
+	if (!ndev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(ndev, &spi->dev);
+
+	ndev->netdev_ops = &mcp25xxfd_netdev_ops;
+	ndev->irq = spi->irq;
+	ndev->flags |= IFF_ECHO;
+
+	priv = netdev_priv(ndev);
+	spi_set_drvdata(spi, priv);
+	priv->can.clock.freq = freq;
+	priv->can.do_set_mode = mcp25xxfd_set_mode;
+	priv->can.do_get_berr_counter = mcp25xxfd_get_berr_counter;
+	priv->can.bittiming_const = &mcp25xxfd_bittiming_const;
+	priv->can.data_bittiming_const = &mcp25xxfd_data_bittiming_const;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING |
+		CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO;
+	priv->ndev = ndev;
+	priv->spi = spi;
+	priv->rx_int = rx_int;
+	priv->clk = clk;
+	priv->reg_vdd = reg_vdd;
+	priv->reg_xceiver = reg_xceiver;
+
+	match = device_get_match_data(&spi->dev);
+	if (match)
+		priv->devtype_data = *(struct mcp25xxfd_devtype_data *)match;
+	else
+		priv->devtype_data = *(struct mcp25xxfd_devtype_data *)
+			spi_get_device_id(spi)->driver_data;
+
+	/* According to the datasheet the SPI clock must be less or
+	 * equal SYSCLOCK / 2.
+	 *
+	 * It turns out, that the Controller is not stable at this
+	 * rate. Known good and bad combinations are:
+	 *
+	 * MCP	ext-clk	SoC			SPI			SPI-clk		max-clk	parent-clk	Status	config
+	 *
+	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 8333333 Hz	 83.33%	600000000 Hz	good	assigned-clocks = <&ccu CLK_SPIx>
+	 * 2518	20 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	 9375000 Hz	 93.75%	600000000 Hz	bad	assigned-clocks = <&ccu CLK_SPIx>
+	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	16666667 Hz	 83.33%	600000000 Hz	good	assigned-clocks = <&ccu CLK_SPIx>
+	 * 2518	40 MHz	allwinner,sun8i-h3	allwinner,sun8i-h3-spi	18750000 Hz	 93.75%	600000000 Hz	bad	assigned-clocks = <&ccu CLK_SPIx>
+	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 8333333 Hz	 83.33%	 16666667 Hz	good	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
+	 * 2517	20 MHz	fsl,imx8mm		fsl,imx51-ecspi		 9523809 Hz	 95.34%	 28571429 Hz	bad	assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
+	 * 2517 40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	good	default
+	 * 2518 40 MHz	atmel,sama5d27		atmel,at91rm9200-spi	16400000 Hz	 82.00%	 82000000 Hz	good	default
+	 *
+	 * Limit SPI clock to 85% of SYSCLOCK / 2 for now.
+	 */
+	priv->spi_max_speed_hz_orig = spi->max_speed_hz;
+	spi->max_speed_hz = min(spi->max_speed_hz, freq / 2 / 1000 * 850);
+	spi->bits_per_word = 8;
+	spi->rt = true;
+	err = spi_setup(spi);
+	if (err)
+		goto out_free_candev;
+
+	err = mcp25xxfd_regmap_init(priv);
+	if (err)
+		goto out_free_candev;
+
+	err = can_rx_offload_add_manual(ndev, &priv->offload,
+					MCP25XXFD_NAPI_WEIGHT);
+	if (err)
+		goto out_free_candev;
+
+	err = mcp25xxfd_register(priv);
+	if (err)
+		goto out_free_candev;
+
+	return 0;
+
+ out_free_candev:
+	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
+
+	free_candev(ndev);
+
+	return err;
+}
+
+static int mcp25xxfd_remove(struct spi_device *spi)
+{
+	struct mcp25xxfd_priv *priv = spi_get_drvdata(spi);
+	struct net_device *ndev = priv->ndev;
+
+	can_rx_offload_del(&priv->offload);
+	mcp25xxfd_unregister(priv);
+	spi->max_speed_hz = priv->spi_max_speed_hz_orig;
+	free_candev(ndev);
+
+	return 0;
+}
+
+static int __maybe_unused mcp25xxfd_runtime_suspend(struct device *device)
+{
+	const struct mcp25xxfd_priv *priv = dev_get_drvdata(device);
+
+	return mcp25xxfd_clks_and_vdd_disable(priv);
+}
+
+static int __maybe_unused mcp25xxfd_runtime_resume(struct device *device)
+{
+	const struct mcp25xxfd_priv *priv = dev_get_drvdata(device);
+
+	return mcp25xxfd_clks_and_vdd_enable(priv);
+}
+
+static const struct dev_pm_ops mcp25xxfd_pm_ops = {
+	SET_RUNTIME_PM_OPS(mcp25xxfd_runtime_suspend,
+			   mcp25xxfd_runtime_resume, NULL)
+};
+
+static struct spi_driver mcp25xxfd_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.pm = &mcp25xxfd_pm_ops,
+		.of_match_table = mcp25xxfd_of_match,
+	},
+	.probe = mcp25xxfd_probe,
+	.remove = mcp25xxfd_remove,
+	.id_table = mcp25xxfd_id_table,
+};
+module_spi_driver(mcp25xxfd_driver);
+
+MODULE_AUTHOR("Marc Kleine-Budde <mkl@...gutronix.de>");
+MODULE_DESCRIPTION("Microchip MCP25xxFD Family CAN controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.28.0

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