Re: [PATCH v8 1/4] can: m_can: Create a m_can platform framework

[Wolfgang Grandegger <wg@grandegger.com>]

Hello Dan,

in the previous email you said that the tcan4x5x uses:

  Bosch M-CAN Revision 3.2.1.1

This means "cdev->version == 32", hence it's using FIFOs...

Am 12.03.19 um 13:12 schrieb Dan Murphy:
> Create a m_can platform framework that peripherial
> devices can register to and use common code and register sets.
> The peripherial devices may provide read/write and configuration
> support of the IP.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> 
> v8 - Added a clean function for the tx_skb, cleaned up skb on BUS_OFF and on xmit
> BUSY - https://lore.kernel.org/patchwork/patch/1047980/
> 
> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
> 
>  drivers/net/can/m_can/Kconfig          |  13 +-
>  drivers/net/can/m_can/Makefile         |   1 +
>  drivers/net/can/m_can/m_can.c          | 717 +++++++++++++------------
>  drivers/net/can/m_can/m_can.h          | 110 ++++
>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>  5 files changed, 699 insertions(+), 344 deletions(-)
>  create mode 100644 drivers/net/can/m_can/m_can.h
>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
> 
> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
> index 04f20dd39007..f7119fd72df4 100644
> --- a/drivers/net/can/m_can/Kconfig
> +++ b/drivers/net/can/m_can/Kconfig
> @@ -1,5 +1,14 @@
>  config CAN_M_CAN
> +	tristate "Bosch M_CAN support"
> +	---help---
> +	  Say Y here if you want support for Bosch M_CAN controller framework.
> +	  This is common support for devices that embed the Bosch M_CAN IP.
> +
> +config CAN_M_CAN_PLATFORM
> +	tristate "Bosch M_CAN support for io-mapped devices"
>  	depends on HAS_IOMEM
> -	tristate "Bosch M_CAN devices"
> +	depends on CAN_M_CAN
>  	---help---
> -	  Say Y here if you want to support for Bosch M_CAN controller.
> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
> +	  This support is for devices that have the Bosch M_CAN controller
> +	  IP embedded into the device and the IP is IO Mapped to the processor.
> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
> index 8bbd7f24f5be..057bbcdb3c74 100644
> --- a/drivers/net/can/m_can/Makefile
> +++ b/drivers/net/can/m_can/Makefile
> @@ -3,3 +3,4 @@
>  #
>  
>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 9b449400376b..f2231fb02525 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -1,20 +1,14 @@
> -/*
> - * CAN bus driver for Bosch M_CAN controller
> - *
> - * Copyright (C) 2014 Freescale Semiconductor, Inc.
> - *	Dong Aisheng <b29396@freescale.com>
> - *
> - * Bosch M_CAN user manual can be obtained from:
> +// SPDX-License-Identifier: GPL-2.0
> +// CAN bus driver for Bosch M_CAN controller
> +// Copyright (C) 2014 Freescale Semiconductor, Inc.
> +//      Dong Aisheng <b29396@freescale.com>
> +// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
> +
> +/* Bosch M_CAN user manual can be obtained from:
>   * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
>   * mcan_users_manual_v302.pdf
> - *
> - * This file is licensed under the terms of the GNU General Public
> - * License version 2. This program is licensed "as is" without any
> - * warranty of any kind, whether express or implied.
>   */
>  
> -#include <linux/clk.h>
> -#include <linux/delay.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/kernel.h>
> @@ -28,11 +22,7 @@
>  #include <linux/can/dev.h>
>  #include <linux/pinctrl/consumer.h>
>  
> -/* napi related */
> -#define M_CAN_NAPI_WEIGHT	64
> -
> -/* message ram configuration data length */
> -#define MRAM_CFG_LEN	8
> +#include "m_can.h"
>  
>  /* registers definition */
>  enum m_can_reg {
> @@ -86,28 +76,11 @@ enum m_can_reg {
>  	M_CAN_TXEFA	= 0xf8,
>  };
>  
> -/* m_can lec values */
> -enum m_can_lec_type {
> -	LEC_NO_ERROR = 0,
> -	LEC_STUFF_ERROR,
> -	LEC_FORM_ERROR,
> -	LEC_ACK_ERROR,
> -	LEC_BIT1_ERROR,
> -	LEC_BIT0_ERROR,
> -	LEC_CRC_ERROR,
> -	LEC_UNUSED,
> -};
> +/* napi related */
> +#define M_CAN_NAPI_WEIGHT	64
>  
> -enum m_can_mram_cfg {
> -	MRAM_SIDF = 0,
> -	MRAM_XIDF,
> -	MRAM_RXF0,
> -	MRAM_RXF1,
> -	MRAM_RXB,
> -	MRAM_TXE,
> -	MRAM_TXB,
> -	MRAM_CFG_NUM,
> -};
> +/* message ram configuration data length */
> +#define MRAM_CFG_LEN	8
>  
>  /* Core Release Register (CREL) */
>  #define CREL_REL_SHIFT		28
> @@ -347,68 +320,72 @@ enum m_can_mram_cfg {
>  #define TX_EVENT_MM_SHIFT	TX_BUF_MM_SHIFT
>  #define TX_EVENT_MM_MASK	(0xff << TX_EVENT_MM_SHIFT)
>  
> -/* address offset and element number for each FIFO/Buffer in the Message RAM */
> -struct mram_cfg {
> -	u16 off;
> -	u8  num;
> -};
> -
> -/* m_can private data structure */
> -struct m_can_priv {
> -	struct can_priv can;	/* must be the first member */
> -	struct napi_struct napi;
> -	struct net_device *dev;
> -	struct device *device;
> -	struct clk *hclk;
> -	struct clk *cclk;
> -	void __iomem *base;
> -	u32 irqstatus;
> -	int version;
> -
> -	/* message ram configuration */
> -	void __iomem *mram_base;
> -	struct mram_cfg mcfg[MRAM_CFG_NUM];
> -};
> +static u32 m_can_read(struct m_can_priv *priv, enum m_can_reg reg)
> +{
> +	if (priv->ops->read_reg)
> +		return priv->ops->read_reg(priv, reg);
> +	else
> +		return -EINVAL;
> +}
>  
> -static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
> +static int m_can_write(struct m_can_priv *priv, enum m_can_reg reg, u32 val)
>  {
> -	return readl(priv->base + reg);
> +	if (priv->ops->write_reg)
> +		return priv->ops->write_reg(priv, reg, val);
> +	else
> +		return -EINVAL;
>  }
>  
> -static inline void m_can_write(const struct m_can_priv *priv,
> -			       enum m_can_reg reg, u32 val)
> +static u32 m_can_fifo_read(struct m_can_priv *priv,
> +			   u32 fgi, unsigned int offset)
>  {
> -	writel(val, priv->base + reg);
> +	u32 addr_offset = priv->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
> +			  offset;
> +
> +	if (priv->ops->read_fifo)
> +		return priv->ops->read_fifo(priv, addr_offset);
> +	else
> +		return -EINVAL;
>  }
>  
> -static inline u32 m_can_fifo_read(const struct m_can_priv *priv,
> -				  u32 fgi, unsigned int offset)
> +static u32 m_can_fifo_write(struct m_can_priv *priv,
> +			    u32 fpi, unsigned int offset, u32 val)
>  {
> -	return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off +
> -		     fgi * RXF0_ELEMENT_SIZE + offset);
> +	u32 addr_offset = priv->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
> +			  offset;
> +
> +	if (priv->ops->write_fifo)
> +		return priv->ops->write_fifo(priv, addr_offset, val);
> +	else
> +		return -EINVAL;
>  }
>  
> -static inline void m_can_fifo_write(const struct m_can_priv *priv,
> -				    u32 fpi, unsigned int offset, u32 val)
> +static u32 m_can_fifo_write_no_off(struct m_can_priv *priv,
> +				   u32 fpi, u32 val)
>  {
> -	writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
> -	       fpi * TXB_ELEMENT_SIZE + offset);
> +	if (priv->ops->write_fifo)
> +		return priv->ops->write_fifo(priv, fpi, val);
> +	else
> +		return 0;
>  }
>  
> -static inline u32 m_can_txe_fifo_read(const struct m_can_priv *priv,
> -				      u32 fgi,
> -				      u32 offset) {
> -	return readl(priv->mram_base + priv->mcfg[MRAM_TXE].off +
> -			fgi * TXE_ELEMENT_SIZE + offset);
> +static u32 m_can_txe_fifo_read(struct m_can_priv *priv, u32 fgi, u32 offset)
> +{
> +	u32 addr_offset = priv->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
> +			  offset;
> +
> +	if (priv->ops->read_fifo)
> +		return priv->ops->read_fifo(priv, addr_offset);
> +	else
> +		return -EINVAL;
>  }
>  
> -static inline bool m_can_tx_fifo_full(const struct m_can_priv *priv)
> +static inline bool m_can_tx_fifo_full(struct m_can_priv *priv)
>  {
>  		return !!(m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQF);
>  }
>  
> -static inline void m_can_config_endisable(const struct m_can_priv *priv,
> -					  bool enable)
> +void m_can_config_endisable(struct m_can_priv *priv, bool enable)
>  {
>  	u32 cccr = m_can_read(priv, M_CAN_CCCR);
>  	u32 timeout = 10;
> @@ -430,7 +407,7 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
>  
>  	while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
>  		if (timeout == 0) {
> -			netdev_warn(priv->dev, "Failed to init module\n");
> +			netdev_warn(priv->net, "Failed to init module\n");
>  			return;
>  		}
>  		timeout--;
> @@ -438,17 +415,29 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
>  	}
>  }
>  
> -static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv)
> +static inline void m_can_enable_all_interrupts(struct m_can_priv *priv)
>  {
>  	/* Only interrupt line 0 is used in this driver */
>  	m_can_write(priv, M_CAN_ILE, ILE_EINT0);
>  }
>  
> -static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
> +static inline void m_can_disable_all_interrupts(struct m_can_priv *priv)
>  {
>  	m_can_write(priv, M_CAN_ILE, 0x0);
>  }
>  
> +static void m_can_clean(struct net_device *net)
> +{
> +	struct m_can_priv *priv = netdev_priv(net);
> +
> +	if (priv->tx_skb) {
> +		net->stats.tx_errors++;
> +		dev_kfree_skb(priv->tx_skb);
> +		can_free_echo_skb(priv->net, 0);

I think this frees the skb twice!

Also, the index depends on "cdev->version"! If > 30, the last used index
should be selected.

> +		priv->tx_skb = NULL;
> +	}
> +}
> +
>  static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
>  {
>  	struct net_device_stats *stats = &dev->stats;
> @@ -633,9 +622,12 @@ static int m_can_clk_start(struct m_can_priv *priv)
>  {
>  	int err;
>  
> -	err = pm_runtime_get_sync(priv->device);
> +	if (priv->pm_clock_support == 0)
> +		return 0;
> +
> +	err = pm_runtime_get_sync(priv->dev);
>  	if (err < 0) {
> -		pm_runtime_put_noidle(priv->device);
> +		pm_runtime_put_noidle(priv->dev);
>  		return err;
>  	}
>  
> @@ -644,7 +636,8 @@ static int m_can_clk_start(struct m_can_priv *priv)
>  
>  static void m_can_clk_stop(struct m_can_priv *priv)
>  {
> -	pm_runtime_put_sync(priv->device);
> +	if (priv->pm_clock_support)
> +		pm_runtime_put_sync(priv->dev);
>  }
>  
>  static int m_can_get_berr_counter(const struct net_device *dev,
> @@ -811,9 +804,8 @@ static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
>  	return work_done;
>  }
>  
> -static int m_can_poll(struct napi_struct *napi, int quota)
> +static int m_can_rx_handler(struct net_device *dev, int quota)
>  {
> -	struct net_device *dev = napi->dev;
>  	struct m_can_priv *priv = netdev_priv(dev);
>  	int work_done = 0;
>  	u32 irqstatus, psr;
> @@ -831,13 +823,33 @@ static int m_can_poll(struct napi_struct *napi, int quota)
>  
>  	if (irqstatus & IR_RF0N)
>  		work_done += m_can_do_rx_poll(dev, (quota - work_done));
> +end:
> +	return work_done;
> +}
> +
> +static int m_can_rx_peripherial(struct net_device *dev)
> +{
> +	struct m_can_priv *priv = netdev_priv(dev);
> +
> +	m_can_rx_handler(dev, 1);
> +
> +	m_can_enable_all_interrupts(priv);
>  
> +	return 0;
> +}
> +
> +static int m_can_poll(struct napi_struct *napi, int quota)
> +{
> +	struct net_device *dev = napi->dev;
> +	struct m_can_priv *priv = netdev_priv(dev);
> +	int work_done;
> +
> +	work_done = m_can_rx_handler(dev, quota);
>  	if (work_done < quota) {
>  		napi_complete_done(napi, work_done);
>  		m_can_enable_all_interrupts(priv);
>  	}
>  
> -end:
>  	return work_done;
>  }
>  
> @@ -894,6 +906,9 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
>  	if (ir & IR_ALL_INT)
>  		m_can_write(priv, M_CAN_IR, ir);
>  
> +	if (priv->ops->clear_interrupts)
> +		priv->ops->clear_interrupts(priv);
> +
>  	/* schedule NAPI in case of
>  	 * - rx IRQ
>  	 * - state change IRQ
> @@ -902,7 +917,10 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
>  	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
>  		priv->irqstatus = ir;
>  		m_can_disable_all_interrupts(priv);
> -		napi_schedule(&priv->napi);
> +		if (!priv->is_peripherial)
> +			napi_schedule(&priv->napi);
> +		else
> +			m_can_rx_peripherial(dev);
>  	}
>  
>  	if (priv->version == 30) {
> @@ -1155,6 +1173,9 @@ static void m_can_chip_config(struct net_device *dev)
>  	m_can_set_bittiming(dev);
>  
>  	m_can_config_endisable(priv, false);
> +
> +	if (priv->ops->init)
> +		priv->ops->init(priv);
>  }
>  
>  static void m_can_start(struct net_device *dev)
> @@ -1173,6 +1194,7 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
>  {
>  	switch (mode) {
>  	case CAN_MODE_START:
> +		m_can_clean(dev);
>  		m_can_start(dev);
>  		netif_wake_queue(dev);
>  		break;
> @@ -1188,20 +1210,17 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
>   * else it returns the release and step coded as:
>   * return value = 10 * <release> + 1 * <step>
>   */
> -static int m_can_check_core_release(void __iomem *m_can_base)
> +static int m_can_check_core_release(struct m_can_priv *priv)
>  {
>  	u32 crel_reg;
>  	u8 rel;
>  	u8 step;
>  	int res;
> -	struct m_can_priv temp_priv = {
> -		.base = m_can_base
> -	};
>  
>  	/* Read Core Release Version and split into version number
>  	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
>  	 */
> -	crel_reg = m_can_read(&temp_priv, M_CAN_CREL);
> +	crel_reg = m_can_read(priv, M_CAN_CREL);
>  	rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);
>  	step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);
>  
> @@ -1219,18 +1238,26 @@ static int m_can_check_core_release(void __iomem *m_can_base)
>  /* Selectable Non ISO support only in version 3.2.x
>   * This function checks if the bit is writable.
>   */
> -static bool m_can_niso_supported(const struct m_can_priv *priv)
> +static bool m_can_niso_supported(struct m_can_priv *priv)
>  {
> -	u32 cccr_reg, cccr_poll;
> -	int niso_timeout;
> +	u32 cccr_reg, cccr_poll = 0;
> +	int niso_timeout = -ETIMEDOUT;
> +	int i;
>  
>  	m_can_config_endisable(priv, true);
>  	cccr_reg = m_can_read(priv, M_CAN_CCCR);
>  	cccr_reg |= CCCR_NISO;
>  	m_can_write(priv, M_CAN_CCCR, cccr_reg);
>  
> -	niso_timeout = readl_poll_timeout((priv->base + M_CAN_CCCR), cccr_poll,
> -					  (cccr_poll == cccr_reg), 0, 10);
> +	for (i = 0; i <= 10; i++) {
> +		cccr_poll = m_can_read(priv, M_CAN_CCCR);
> +		if (cccr_poll == cccr_reg) {
> +			niso_timeout = 0;
> +			break;
> +		}
> +
> +		usleep_range(1, 5);
> +	}
>  
>  	/* Clear NISO */
>  	cccr_reg &= ~(CCCR_NISO);
> @@ -1242,107 +1269,79 @@ static bool m_can_niso_supported(const struct m_can_priv *priv)
>  	return !niso_timeout;
>  }
>  
> -static int m_can_dev_setup(struct platform_device *pdev, struct net_device *dev,
> -			   void __iomem *addr)
> +static int m_can_dev_setup(struct m_can_priv *m_can_dev)
>  {
> -	struct m_can_priv *priv;
> +	struct net_device *dev = m_can_dev->net;
>  	int m_can_version;
>  
> -	m_can_version = m_can_check_core_release(addr);
> +	m_can_version = m_can_check_core_release(m_can_dev);
>  	/* return if unsupported version */
>  	if (!m_can_version) {
> -		dev_err(&pdev->dev, "Unsupported version number: %2d",
> +		dev_err(m_can_dev->dev, "Unsupported version number: %2d",
>  			m_can_version);
>  		return -EINVAL;
>  	}
>  
> -	priv = netdev_priv(dev);
> -	netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
> +	if (!m_can_dev->is_peripherial)
> +		netif_napi_add(dev, &m_can_dev->napi,
> +			       m_can_poll, M_CAN_NAPI_WEIGHT);
>  
>  	/* Shared properties of all M_CAN versions */
> -	priv->version = m_can_version;
> -	priv->dev = dev;
> -	priv->base = addr;
> -	priv->can.do_set_mode = m_can_set_mode;
> -	priv->can.do_get_berr_counter = m_can_get_berr_counter;
> +	m_can_dev->version = m_can_version;
> +	m_can_dev->can.do_set_mode = m_can_set_mode;
> +	m_can_dev->can.do_get_berr_counter = m_can_get_berr_counter;
>  
>  	/* Set M_CAN supported operations */
> -	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
> +	m_can_dev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
>  					CAN_CTRLMODE_LISTENONLY |
>  					CAN_CTRLMODE_BERR_REPORTING |
>  					CAN_CTRLMODE_FD;
>  
>  	/* Set properties depending on M_CAN version */
> -	switch (priv->version) {
> +	switch (m_can_dev->version) {
>  	case 30:
>  		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
>  		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
> -		priv->can.bittiming_const = &m_can_bittiming_const_30X;
> -		priv->can.data_bittiming_const =
> -				&m_can_data_bittiming_const_30X;
> +		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
> +			m_can_dev->bit_timing : &m_can_bittiming_const_30X;
> +
> +		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
> +						m_can_dev->data_timing :
> +						&m_can_data_bittiming_const_30X;
>  		break;
>  	case 31:
>  		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
>  		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
> -		priv->can.bittiming_const = &m_can_bittiming_const_31X;
> -		priv->can.data_bittiming_const =
> -				&m_can_data_bittiming_const_31X;
> +		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
> +			m_can_dev->bit_timing : &m_can_bittiming_const_31X;
> +
> +		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
> +						m_can_dev->data_timing :
> +						&m_can_data_bittiming_const_31X;
>  		break;
>  	case 32:
> -		priv->can.bittiming_const = &m_can_bittiming_const_31X;
> -		priv->can.data_bittiming_const =
> -				&m_can_data_bittiming_const_31X;
> -		priv->can.ctrlmode_supported |= (m_can_niso_supported(priv)
> +		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
> +			m_can_dev->bit_timing : &m_can_bittiming_const_31X;
> +
> +		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
> +						m_can_dev->data_timing :
> +						&m_can_data_bittiming_const_31X;
> +
> +		m_can_dev->can.ctrlmode_supported |=
> +						(m_can_niso_supported(m_can_dev)
>  						? CAN_CTRLMODE_FD_NON_ISO
>  						: 0);
>  		break;
>  	default:
> -		dev_err(&pdev->dev, "Unsupported version number: %2d",
> -			priv->version);
> +		dev_err(m_can_dev->dev, "Unsupported version number: %2d",
> +			m_can_dev->version);
>  		return -EINVAL;
>  	}
>  
> -	return 0;
> -}
> -
> -static int m_can_open(struct net_device *dev)
> -{
> -	struct m_can_priv *priv = netdev_priv(dev);
> -	int err;
> -
> -	err = m_can_clk_start(priv);
> -	if (err)
> -		return err;
> -
> -	/* open the can device */
> -	err = open_candev(dev);
> -	if (err) {
> -		netdev_err(dev, "failed to open can device\n");
> -		goto exit_disable_clks;
> -	}
> -
> -	/* register interrupt handler */
> -	err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
> -			  dev);
> -	if (err < 0) {
> -		netdev_err(dev, "failed to request interrupt\n");
> -		goto exit_irq_fail;
> -	}
> -
> -	/* start the m_can controller */
> -	m_can_start(dev);
> -
> -	can_led_event(dev, CAN_LED_EVENT_OPEN);
> -	napi_enable(&priv->napi);
> -	netif_start_queue(dev);
> +	if (m_can_dev->ops->init)
> +		m_can_dev->ops->init(m_can_dev);
>  
>  	return 0;
> -
> -exit_irq_fail:
> -	close_candev(dev);
> -exit_disable_clks:
> -	m_can_clk_stop(priv);
> -	return err;
>  }
>  
>  static void m_can_stop(struct net_device *dev)
> @@ -1361,10 +1360,18 @@ static int m_can_close(struct net_device *dev)
>  	struct m_can_priv *priv = netdev_priv(dev);
>  
>  	netif_stop_queue(dev);
> -	napi_disable(&priv->napi);
> +	if (!priv->is_peripherial)
> +		napi_disable(&priv->napi);
>  	m_can_stop(dev);
>  	m_can_clk_stop(priv);
>  	free_irq(dev->irq, dev);
> +
> +	if (priv->is_peripherial) {
> +		priv->tx_skb = NULL;
> +		destroy_workqueue(priv->tx_wq);
> +		priv->tx_wq = NULL;
> +	}
> +
>  	close_candev(dev);
>  	can_led_event(dev, CAN_LED_EVENT_STOP);
>  
> @@ -1385,18 +1392,15 @@ static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
>  	return !!priv->can.echo_skb[next_idx];
>  }
>  
> -static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
> -				    struct net_device *dev)
> +static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
>  {
> -	struct m_can_priv *priv = netdev_priv(dev);
> -	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
> +	struct canfd_frame *cf = (struct canfd_frame *)priv->tx_skb->data;
> +	struct net_device *dev = priv->net;
> +	struct sk_buff *skb = priv->tx_skb;
>  	u32 id, cccr, fdflags;
>  	int i;
>  	int putidx;
>  
> -	if (can_dropped_invalid_skb(dev, skb))
> -		return NETDEV_TX_OK;
> -
>  	/* Generate ID field for TX buffer Element */
>  	/* Common to all supported M_CAN versions */
>  	if (cf->can_id & CAN_EFF_FLAG) {
> @@ -1492,14 +1496,117 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>  		m_can_write(priv, M_CAN_TXBAR, (1 << putidx));
>  
>  		/* stop network queue if fifo full */
> -			if (m_can_tx_fifo_full(priv) ||
> -			    m_can_next_echo_skb_occupied(dev, putidx))
> -				netif_stop_queue(dev);
> +		if (m_can_tx_fifo_full(priv) ||
> +		    m_can_next_echo_skb_occupied(dev, putidx))
> +			netif_stop_queue(dev);
> +	}
> +
> +	return NETDEV_TX_OK;
> +}
> +
> +static void m_can_tx_work_queue(struct work_struct *ws)
> +{
> +	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
> +						tx_work);
> +	netdev_tx_t ret;
> +
> +	ret = m_can_tx_handler(priv);
> +	if (ret == NETDEV_TX_OK)
> +		priv->tx_skb = NULL;

What happens to the "tx_skb" if this funtions returns with
NETDEV_TX_BUSY? Will it be freed?

> +}
> +
> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
> +				    struct net_device *dev)
> +{
> +	struct m_can_priv *priv = netdev_priv(dev);
> +
> +	if (can_dropped_invalid_skb(dev, skb))
> +		return NETDEV_TX_OK;
> +
> +	if (priv->is_peripherial) {
> +		if (priv->tx_skb) {
> +			netdev_err(dev, "hard_xmit called while tx busy\n");
> +			return NETDEV_TX_BUSY;
> +		}
> +
> +		if (priv->can.state == CAN_STATE_BUS_OFF) {
> +			m_can_clean(dev);
> +		} else {
> +			priv->tx_skb = skb;
> +			netif_stop_queue(priv->net);

You stop the queue immediately, even if fifos are used. Is this by purpose?

> +			queue_work(priv->tx_wq, &priv->tx_work);
> +		}
> +	} else {
> +		priv->tx_skb = skb;
> +		return m_can_tx_handler(priv);
>  	}
>  
>  	return NETDEV_TX_OK;
>  }
>  
> +static int m_can_open(struct net_device *dev)
> +{
> +	struct m_can_priv *priv = netdev_priv(dev);
> +	int err;
> +
> +	err = m_can_clk_start(priv);
> +	if (err)
> +		return err;
> +
> +	/* open the can device */
> +	err = open_candev(dev);
> +	if (err) {
> +		netdev_err(dev, "failed to open can device\n");
> +		goto exit_disable_clks;
> +	}
> +
> +	/* register interrupt handler */
> +	if (priv->is_peripherial) {
> +		priv->tx_skb = NULL;
> +		priv->tx_wq = alloc_workqueue("mcan_wq",
> +					      WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
> +		if (!priv->tx_wq) {
> +			err = -ENOMEM;
> +			goto out_wq_fail;
> +		}
> +
> +		INIT_WORK(&priv->tx_work, m_can_tx_work_queue);
> +
> +		err = request_threaded_irq(dev->irq, NULL, m_can_isr,
> +					   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
> +					   dev->name, dev);
> +	} else {
> +		err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
> +				  dev);
> +	}
> +
> +	if (err < 0) {
> +		netdev_err(dev, "failed to request interrupt\n");
> +		goto exit_irq_fail;
> +	}
> +
> +	/* start the m_can controller */
> +	m_can_start(dev);
> +
> +	can_led_event(dev, CAN_LED_EVENT_OPEN);
> +
> +	if (!priv->is_peripherial)
> +		napi_enable(&priv->napi);
> +
> +	netif_start_queue(dev);
> +
> +	return 0;
> +
> +exit_irq_fail:
> +	if (priv->is_peripherial)
> +		destroy_workqueue(priv->tx_wq);
> +out_wq_fail:
> +	close_candev(dev);
> +exit_disable_clks:
> +	m_can_clk_stop(priv);
> +	return err;
> +}
> +
>  static const struct net_device_ops m_can_netdev_ops = {
>  	.ndo_open = m_can_open,
>  	.ndo_stop = m_can_close,
> @@ -1515,20 +1622,6 @@ static int register_m_can_dev(struct net_device *dev)
>  	return register_candev(dev);
>  }
>  
> -static void m_can_init_ram(struct m_can_priv *priv)
> -{
> -	int end, i, start;
> -
> -	/* initialize the entire Message RAM in use to avoid possible
> -	 * ECC/parity checksum errors when reading an uninitialized buffer
> -	 */
> -	start = priv->mcfg[MRAM_SIDF].off;
> -	end = priv->mcfg[MRAM_TXB].off +
> -		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
> -	for (i = start; i < end; i += 4)
> -		writel(0x0, priv->mram_base + i);
> -}
> -
>  static void m_can_of_parse_mram(struct m_can_priv *priv,
>  				const u32 *mram_config_vals)
>  {
> @@ -1556,9 +1649,8 @@ static void m_can_of_parse_mram(struct m_can_priv *priv,
>  	priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &
>  			(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);
>  
> -	dev_dbg(priv->device,
> -		"mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
> -		priv->mram_base,
> +	dev_dbg(priv->dev,
> +		"sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
>  		priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
>  		priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
>  		priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
> @@ -1566,63 +1658,55 @@ static void m_can_of_parse_mram(struct m_can_priv *priv,
>  		priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
>  		priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
>  		priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
> -
> -	m_can_init_ram(priv);
>  }
>  
> -static int m_can_plat_probe(struct platform_device *pdev)
> +void m_can_init_ram(struct m_can_priv *priv)
>  {
> -	struct net_device *dev;
> -	struct m_can_priv *priv;
> -	struct resource *res;
> -	void __iomem *addr;
> -	void __iomem *mram_addr;
> -	struct clk *hclk, *cclk;
> -	int irq, ret;
> -	struct device_node *np;
> -	u32 mram_config_vals[MRAM_CFG_LEN];
> -	u32 tx_fifo_size;
> -
> -	np = pdev->dev.of_node;
> +	int end, i, start;
>  
> -	hclk = devm_clk_get(&pdev->dev, "hclk");
> -	cclk = devm_clk_get(&pdev->dev, "cclk");
> +	/* initialize the entire Message RAM in use to avoid possible
> +	 * ECC/parity checksum errors when reading an uninitialized buffer
> +	 */
> +	start = priv->mcfg[MRAM_SIDF].off;
> +	end = priv->mcfg[MRAM_TXB].off +
> +		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
>  
> -	if (IS_ERR(hclk) || IS_ERR(cclk)) {
> -		dev_err(&pdev->dev, "no clock found\n");
> -		ret = -ENODEV;
> -		goto failed_ret;
> -	}
> +	for (i = start; i < end; i += 4)
> +		m_can_fifo_write_no_off(priv, i, 0x0);
> +}
> +EXPORT_SYMBOL_GPL(m_can_init_ram);
>  
> -	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
> -	addr = devm_ioremap_resource(&pdev->dev, res);
> -	irq = platform_get_irq_byname(pdev, "int0");
> +int m_can_class_get_clocks(struct m_can_priv *m_can_dev)
> +{
> +	int ret = 0;
>  
> -	if (IS_ERR(addr) || irq < 0) {
> -		ret = -EINVAL;
> -		goto failed_ret;
> -	}
> +	m_can_dev->hclk = devm_clk_get(m_can_dev->dev, "hclk");
> +	m_can_dev->cclk = devm_clk_get(m_can_dev->dev, "cclk");
>  
> -	/* message ram could be shared */
> -	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
> -	if (!res) {
> +	if (IS_ERR(m_can_dev->cclk)) {
> +		dev_err(m_can_dev->dev, "no clock found\n");
>  		ret = -ENODEV;
> -		goto failed_ret;
>  	}
>  
> -	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> -	if (!mram_addr) {
> -		ret = -ENOMEM;
> -		goto failed_ret;
> -	}
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
>  
> -	/* get message ram configuration */
> -	ret = of_property_read_u32_array(np, "bosch,mram-cfg",
> -					 mram_config_vals,
> -					 sizeof(mram_config_vals) / 4);
> +struct m_can_priv *m_can_class_allocate_dev(struct device *dev)
> +{
> +	struct m_can_priv *class_dev = NULL;
> +	u32 mram_config_vals[MRAM_CFG_LEN];
> +	struct net_device *net_dev;
> +	u32 tx_fifo_size;
> +	int ret;
> +
> +	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> +					     "bosch,mram-cfg",
> +					     mram_config_vals,
> +					     sizeof(mram_config_vals) / 4);
>  	if (ret) {
> -		dev_err(&pdev->dev, "Could not get Message RAM configuration.");
> -		goto failed_ret;
> +		dev_err(dev, "Could not get Message RAM configuration.");
> +		goto out;
>  	}
>  
>  	/* Get TX FIFO size
> @@ -1631,66 +1715,74 @@ static int m_can_plat_probe(struct platform_device *pdev)
>  	tx_fifo_size = mram_config_vals[7];
>  
>  	/* allocate the m_can device */
> -	dev = alloc_candev(sizeof(*priv), tx_fifo_size);
> -	if (!dev) {
> -		ret = -ENOMEM;
> -		goto failed_ret;
> +	net_dev = alloc_candev(sizeof(*class_dev), tx_fifo_size);
> +	if (!net_dev) {
> +		dev_err(dev, "Failed to allocate CAN device");
> +		goto out;
> +	}
> +
> +	class_dev = netdev_priv(net_dev);
> +	if (!class_dev) {
> +		dev_err(dev, "Failed to init netdev private");
> +		goto out;
>  	}
>  
> -	priv = netdev_priv(dev);
> -	dev->irq = irq;
> -	priv->device = &pdev->dev;
> -	priv->hclk = hclk;
> -	priv->cclk = cclk;
> -	priv->can.clock.freq = clk_get_rate(cclk);
> -	priv->mram_base = mram_addr;
> +	class_dev->net = net_dev;
> +	class_dev->dev = dev;
> +	SET_NETDEV_DEV(net_dev, dev);
>  
> -	platform_set_drvdata(pdev, dev);
> -	SET_NETDEV_DEV(dev, &pdev->dev);
> +	m_can_of_parse_mram(class_dev, mram_config_vals);
> +out:
> +	return class_dev;
> +}
> +EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
>  
> -	/* Enable clocks. Necessary to read Core Release in order to determine
> -	 * M_CAN version
> -	 */
> -	pm_runtime_enable(&pdev->dev);
> -	ret = m_can_clk_start(priv);
> -	if (ret)
> -		goto pm_runtime_fail;
> +int m_can_class_register(struct m_can_priv *m_can_dev)
> +{
> +	int ret;
> +
> +	if (m_can_dev->pm_clock_support) {
> +		pm_runtime_enable(m_can_dev->dev);
> +		ret = m_can_clk_start(m_can_dev);
> +		if (ret)
> +			goto pm_runtime_fail;
> +	}
>  
> -	ret = m_can_dev_setup(pdev, dev, addr);
> +	ret = m_can_dev_setup(m_can_dev);
>  	if (ret)
>  		goto clk_disable;
>  
> -	ret = register_m_can_dev(dev);
> +	ret = register_m_can_dev(m_can_dev->net);
>  	if (ret) {
> -		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
> -			KBUILD_MODNAME, ret);
> +		dev_err(m_can_dev->dev, "registering %s failed (err=%d)\n",
> +			m_can_dev->net->name, ret);
>  		goto clk_disable;
>  	}
>  
> -	m_can_of_parse_mram(priv, mram_config_vals);
> +	devm_can_led_init(m_can_dev->net);
>  
> -	devm_can_led_init(dev);
> +	of_can_transceiver(m_can_dev->net);
>  
> -	of_can_transceiver(dev);
> -
> -	dev_info(&pdev->dev, "%s device registered (irq=%d, version=%d)\n",
> -		 KBUILD_MODNAME, dev->irq, priv->version);
> +	dev_info(m_can_dev->dev, "%s device registered (irq=%d, version=%d)\n",
> +		 KBUILD_MODNAME, m_can_dev->net->irq, m_can_dev->version);
>  
>  	/* Probe finished
>  	 * Stop clocks. They will be reactivated once the M_CAN device is opened
>  	 */
>  clk_disable:
> -	m_can_clk_stop(priv);
> +	m_can_clk_stop(m_can_dev);
>  pm_runtime_fail:
>  	if (ret) {
> -		pm_runtime_disable(&pdev->dev);
> -		free_candev(dev);
> +		if (m_can_dev->pm_clock_support)
> +			pm_runtime_disable(m_can_dev->dev);
> +		free_candev(m_can_dev->net);
>  	}
> -failed_ret:
> +
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(m_can_class_register);
>  
> -static __maybe_unused int m_can_suspend(struct device *dev)
> +int m_can_class_suspend(struct device *dev)
>  {
>  	struct net_device *ndev = dev_get_drvdata(dev);
>  	struct m_can_priv *priv = netdev_priv(ndev);
> @@ -1708,8 +1800,9 @@ static __maybe_unused int m_can_suspend(struct device *dev)
>  
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(m_can_class_suspend);
>  
> -static __maybe_unused int m_can_resume(struct device *dev)
> +int m_can_class_resume(struct device *dev)
>  {
>  	struct net_device *ndev = dev_get_drvdata(dev);
>  	struct m_can_priv *priv = netdev_priv(ndev);
> @@ -1733,79 +1826,19 @@ static __maybe_unused int m_can_resume(struct device *dev)
>  
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(m_can_class_resume);
>  
> -static void unregister_m_can_dev(struct net_device *dev)
> -{
> -	unregister_candev(dev);
> -}
> -
> -static int m_can_plat_remove(struct platform_device *pdev)
> -{
> -	struct net_device *dev = platform_get_drvdata(pdev);
> -
> -	unregister_m_can_dev(dev);
> -
> -	pm_runtime_disable(&pdev->dev);
> -
> -	platform_set_drvdata(pdev, NULL);
> -
> -	free_candev(dev);
> -
> -	return 0;
> -}
> -
> -static int __maybe_unused m_can_runtime_suspend(struct device *dev)
> +void m_can_class_unregister(struct m_can_priv *m_can_dev)
>  {
> -	struct net_device *ndev = dev_get_drvdata(dev);
> -	struct m_can_priv *priv = netdev_priv(ndev);
> +	unregister_candev(m_can_dev->net);
>  
> -	clk_disable_unprepare(priv->cclk);
> -	clk_disable_unprepare(priv->hclk);
> +	m_can_clk_stop(m_can_dev);
>  
> -	return 0;
> +	free_candev(m_can_dev->net);
>  }
> -
> -static int __maybe_unused m_can_runtime_resume(struct device *dev)
> -{
> -	struct net_device *ndev = dev_get_drvdata(dev);
> -	struct m_can_priv *priv = netdev_priv(ndev);
> -	int err;
> -
> -	err = clk_prepare_enable(priv->hclk);
> -	if (err)
> -		return err;
> -
> -	err = clk_prepare_enable(priv->cclk);
> -	if (err)
> -		clk_disable_unprepare(priv->hclk);
> -
> -	return err;
> -}
> -
> -static const struct dev_pm_ops m_can_pmops = {
> -	SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
> -			   m_can_runtime_resume, NULL)
> -	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
> -};
> -
> -static const struct of_device_id m_can_of_table[] = {
> -	{ .compatible = "bosch,m_can", .data = NULL },
> -	{ /* sentinel */ },
> -};
> -MODULE_DEVICE_TABLE(of, m_can_of_table);
> -
> -static struct platform_driver m_can_plat_driver = {
> -	.driver = {
> -		.name = KBUILD_MODNAME,
> -		.of_match_table = m_can_of_table,
> -		.pm     = &m_can_pmops,
> -	},
> -	.probe = m_can_plat_probe,
> -	.remove = m_can_plat_remove,
> -};
> -
> -module_platform_driver(m_can_plat_driver);
> +EXPORT_SYMBOL_GPL(m_can_class_unregister);
>  
>  MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
> +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
>  MODULE_LICENSE("GPL v2");
>  MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
> diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
> new file mode 100644
> index 000000000000..b60f27dd9f33
> --- /dev/null
> +++ b/drivers/net/can/m_can/m_can.h
> @@ -0,0 +1,110 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* CAN bus driver for Bosch M_CAN controller
> + * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
> + */
> +
> +#ifndef _CAN_M_CAN_H_
> +#define _CAN_M_CAN_H_
> +
> +#include <linux/can/core.h>
> +#include <linux/can/led.h>
> +#include <linux/completion.h>
> +#include <linux/device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/freezer.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <linux/clk.h>
> +#include <linux/delay.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/pm_runtime.h>
> +#include <linux/iopoll.h>
> +#include <linux/can/dev.h>
> +#include <linux/pinctrl/consumer.h>
> +
> +/* m_can lec values */
> +enum m_can_lec_type {
> +	LEC_NO_ERROR = 0,
> +	LEC_STUFF_ERROR,
> +	LEC_FORM_ERROR,
> +	LEC_ACK_ERROR,
> +	LEC_BIT1_ERROR,
> +	LEC_BIT0_ERROR,
> +	LEC_CRC_ERROR,
> +	LEC_UNUSED,
> +};
> +
> +enum m_can_mram_cfg {
> +	MRAM_SIDF = 0,
> +	MRAM_XIDF,
> +	MRAM_RXF0,
> +	MRAM_RXF1,
> +	MRAM_RXB,
> +	MRAM_TXE,
> +	MRAM_TXB,
> +	MRAM_CFG_NUM,
> +};
> +
> +/* address offset and element number for each FIFO/Buffer in the Message RAM */
> +struct mram_cfg {
> +	u16 off;
> +	u8  num;
> +};
> +
> +struct m_can_priv;
> +struct m_can_ops {
> +	/* Device specific call backs */
> +	int (*clear_interrupts)(struct m_can_priv *m_can_class);
> +	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
> +	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
> +	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
> +	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
> +			  int val);
> +	int (*init)(struct m_can_priv *m_can_class);
> +};
> +
> +struct m_can_priv {
> +	struct can_priv can;
> +	struct napi_struct napi;
> +	struct net_device *net;
> +	struct device *dev;
> +	struct clk *hclk;
> +	struct clk *cclk;
> +
> +	struct workqueue_struct *tx_wq;
> +	struct work_struct tx_work;
> +	struct sk_buff *tx_skb;
> +
> +	struct can_bittiming_const *bit_timing;
> +	struct can_bittiming_const *data_timing;
> +
> +	struct m_can_ops *ops;
> +
> +	void *device_data;
> +
> +	int version;
> +	int freq;
> +	u32 irqstatus;
> +
> +	int pm_clock_support;
> +	int is_peripherial;
> +
> +	struct mram_cfg mcfg[MRAM_CFG_NUM];
> +};
> +
> +struct m_can_priv *m_can_class_allocate_dev(struct device *dev);
> +int m_can_class_register(struct m_can_priv *m_can_dev);
> +void m_can_class_unregister(struct m_can_priv *m_can_dev);
> +int m_can_class_get_clocks(struct m_can_priv *m_can_dev);
> +void m_can_init_ram(struct m_can_priv *priv);
> +void m_can_config_endisable(struct m_can_priv *priv, bool enable);
> +
> +int m_can_class_suspend(struct device *dev);
> +int m_can_class_resume(struct device *dev);
> +#endif	/* _CAN_M_H_ */
> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
> new file mode 100644
> index 000000000000..b02d49f9ee4c
> --- /dev/null
> +++ b/drivers/net/can/m_can/m_can_platform.c
> @@ -0,0 +1,202 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// IOMapped CAN bus driver for Bosch M_CAN controller
> +// Copyright (C) 2014 Freescale Semiconductor, Inc.
> +//	Dong Aisheng <b29396@freescale.com>
> +//
> +// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
> +
> +#include <linux/platform_device.h>
> +
> +#include "m_can.h"
> +
> +struct m_can_plat_priv {
> +	void __iomem *base;
> +	void __iomem *mram_base;
> +};
> +
> +static u32 iomap_read_reg(struct m_can_priv *cdev, int reg)
> +{
> +	struct m_can_plat_priv *priv =
> +			(struct m_can_plat_priv *)cdev->device_data;
> +
> +	return readl(priv->base + reg);
> +}
> +
> +static u32 iomap_read_fifo(struct m_can_priv *cdev, int offset)
> +{
> +	struct m_can_plat_priv *priv =
> +			(struct m_can_plat_priv *)cdev->device_data;
> +
> +	return readl(priv->mram_base + offset);
> +}
> +
> +static int iomap_write_reg(struct m_can_priv *cdev, int reg, int val)
> +{
> +	struct m_can_plat_priv *priv =
> +			(struct m_can_plat_priv *)cdev->device_data;
> +
> +	writel(val, priv->base + reg);
> +
> +	return 0;
> +}
> +
> +static int iomap_write_fifo(struct m_can_priv *cdev, int offset, int val)
> +{
> +	struct m_can_plat_priv *priv =
> +			(struct m_can_plat_priv *)cdev->device_data;
> +
> +	writel(val, priv->mram_base + offset);
> +
> +	return 0;
> +}
> +
> +static struct m_can_ops m_can_plat_ops = {
> +	.read_reg = iomap_read_reg,
> +	.write_reg = iomap_write_reg,
> +	.write_fifo = iomap_write_fifo,
> +	.read_fifo = iomap_read_fifo,
> +};
> +
> +static int m_can_plat_probe(struct platform_device *pdev)
> +{
> +	struct m_can_priv *mcan_class;
> +	struct m_can_plat_priv *priv;
> +	struct resource *res;
> +	void __iomem *addr;
> +	void __iomem *mram_addr;
> +	int irq, ret = 0;
> +
> +	mcan_class = m_can_class_allocate_dev(&pdev->dev);
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	mcan_class->device_data = priv;
> +
> +	m_can_class_get_clocks(mcan_class);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
> +	addr = devm_ioremap_resource(&pdev->dev, res);
> +	irq = platform_get_irq_byname(pdev, "int0");
> +	if (IS_ERR(addr) || irq < 0) {
> +		ret = -EINVAL;
> +		goto failed_ret;
> +	}
> +
> +	/* message ram could be shared */
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
> +	if (!res) {
> +		ret = -ENODEV;
> +		goto failed_ret;
> +	}
> +
> +	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> +	if (!mram_addr) {
> +		ret = -ENOMEM;
> +		goto failed_ret;
> +	}
> +
> +	priv->base = addr;
> +	priv->mram_base = mram_addr;
> +
> +	mcan_class->net->irq = irq;
> +	mcan_class->pm_clock_support = 1;
> +	mcan_class->can.clock.freq = clk_get_rate(mcan_class->cclk);
> +	mcan_class->dev = &pdev->dev;
> +
> +	mcan_class->ops = &m_can_plat_ops;
> +
> +	mcan_class->is_peripherial = false;
> +
> +	platform_set_drvdata(pdev, mcan_class->dev);
> +
> +	m_can_init_ram(mcan_class);
> +
> +	ret = m_can_class_register(mcan_class);
> +
> +failed_ret:
> +	return ret;
> +}
> +
> +static __maybe_unused int m_can_suspend(struct device *dev)
> +{
> +	return m_can_class_suspend(dev);
> +}
> +
> +static __maybe_unused int m_can_resume(struct device *dev)
> +{
> +	return m_can_class_resume(dev);
> +}
> +
> +static int m_can_plat_remove(struct platform_device *pdev)
> +{
> +	struct net_device *dev = platform_get_drvdata(pdev);
> +	struct m_can_priv *mcan_class = netdev_priv(dev);
> +
> +	m_can_class_unregister(mcan_class);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused m_can_runtime_suspend(struct device *dev)
> +{
> +	struct net_device *ndev = dev_get_drvdata(dev);
> +	struct m_can_priv *mcan_class = netdev_priv(ndev);
> +
> +	m_can_class_suspend(dev);
> +
> +	clk_disable_unprepare(mcan_class->cclk);
> +	clk_disable_unprepare(mcan_class->hclk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused m_can_runtime_resume(struct device *dev)
> +{
> +	struct net_device *ndev = dev_get_drvdata(dev);
> +	struct m_can_priv *mcan_class = netdev_priv(ndev);
> +	int err;
> +
> +	err = clk_prepare_enable(mcan_class->hclk);
> +	if (err)
> +		return err;
> +
> +	err = clk_prepare_enable(mcan_class->cclk);
> +	if (err)
> +		clk_disable_unprepare(mcan_class->hclk);
> +
> +	m_can_class_resume(dev);
> +
> +	return err;
> +}
> +
> +static const struct dev_pm_ops m_can_pmops = {
> +	SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
> +			   m_can_runtime_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
> +};
> +
> +static const struct of_device_id m_can_of_table[] = {
> +	{ .compatible = "bosch,m_can", .data = NULL },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, m_can_of_table);
> +
> +static struct platform_driver m_can_plat_driver = {
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +		.of_match_table = m_can_of_table,
> +		.pm     = &m_can_pmops,
> +	},
> +	.probe = m_can_plat_probe,
> +	.remove = m_can_plat_remove,
> +};
> +
> +module_platform_driver(m_can_plat_driver);
> +
> +MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
> +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("M_CAN driver for IO Mapped Bosch controllers");

Wolfgang.