Re: [PATCH 5/5] can: flexcan: add mcf5441x support

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 08.06.2021 22:45:42, Angelo Dureghello wrote:
> Add flexcan support for NXP ColdFire mcf5441x family.
> 
> This flexcan module is quite similar to imx6 flexcan module, but
> with some exceptions:
> 
> - 3 separate interrupt sources, MB, BOFF and ERR,

Please don't hard code the 2 extra interrupts as offsets, but create
proper IRQ resources.

> - implements 16 mb only,
> - m68k architecture is not supporting devicetrees, so a
>   platform data check/case has been added,

You might want to revert:

| 2c0ac9208135 can: flexcan: convert the driver to DT-only

and use it as a starting point.

> - ColdFire is m68k, so big-endian cpu, with a little-endian flexcan
>   module.
> 
> Signed-off-by: Angelo Dureghello <angelo@kernel-space.org>
> ---
>  drivers/net/can/flexcan.c | 80 +++++++++++++++++++++++++++++++--------
>  1 file changed, 65 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index 57f3635ad8d7..af95273327cd 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -28,6 +28,7 @@
>  #include <linux/of_device.h>
>  #include <linux/pinctrl/consumer.h>
>  #include <linux/platform_device.h>
> +#include <linux/platform_data/flexcan-mcf.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
> @@ -205,6 +206,10 @@
>  
>  #define FLEXCAN_TIMEOUT_US		(250)
>  
> +#define FLEXCAN_OFFS_INT_BOFF		1
> +#define FLEXCAN_OFFS_INT_ERR		3
> +#define FLEXCAN_MB_CNT_MCF		16
> +
>  /* FLEXCAN hardware feature flags
>   *
>   * Below is some version info we got:
> @@ -246,6 +251,8 @@
>  #define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
>  /* Setup stop mode with SCU firmware to support wakeup */
>  #define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
> +/* Setup for flexcan module as in mcf, 16 mb, 3 separate interrupts  */
> +#define FLEXCAN_QUIRK_SETUP_MCF BIT(12)
>  
>  /* Structure of the message buffer */
>  struct flexcan_mb {
> @@ -371,6 +378,12 @@ struct flexcan_priv {
>  	void (*write)(u32 val, void __iomem *addr);
>  };
>  
> +static const struct flexcan_devtype_data fsl_mcf_devtype_data = {
> +	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
> +		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> +		FLEXCAN_QUIRK_SETUP_MCF,
> +};
> +
>  static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
>  	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
>  		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
> @@ -637,13 +650,17 @@ static int flexcan_clks_enable(const struct flexcan_priv *priv)
>  {
>  	int err;
>  
> -	err = clk_prepare_enable(priv->clk_ipg);
> -	if (err)
> -		return err;
> +	if (priv->clk_ipg) {
> +		err = clk_prepare_enable(priv->clk_ipg);
> +		if (err)
> +			return err;
> +	}
>  
> -	err = clk_prepare_enable(priv->clk_per);
> -	if (err)
> -		clk_disable_unprepare(priv->clk_ipg);
> +	if (priv->clk_per) {
> +		err = clk_prepare_enable(priv->clk_per);
> +		if (err)
> +			clk_disable_unprepare(priv->clk_ipg);
> +	}
>  
>  	return err;
>  }
> @@ -1401,8 +1418,13 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
>  		priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN;
>  	else
>  		priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
> -	priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
> -			 (sizeof(priv->regs->mb[1]) / priv->mb_size);
> +
> +	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
> +		priv->mb_count = FLEXCAN_MB_CNT_MCF;
> +	} else {
> +		priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
> +				 (sizeof(priv->regs->mb[1]) / priv->mb_size);
> +	}

nitpick: no { } needed

>  
>  	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
>  		priv->tx_mb_reserved =
> @@ -1774,6 +1796,18 @@ static int flexcan_open(struct net_device *dev)
>  	if (err)
>  		goto out_can_rx_offload_disable;
>  
> +	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
> +		err = request_irq(dev->irq + FLEXCAN_OFFS_INT_BOFF,
> +				  flexcan_irq, IRQF_SHARED, dev->name, dev);
> +		if (err)
> +			goto out_can_rx_offload_disable;
> +
> +		err = request_irq(dev->irq + FLEXCAN_OFFS_INT_ERR,
> +				  flexcan_irq, IRQF_SHARED, dev->name, dev);
> +		if (err)
> +			goto out_can_rx_offload_disable;

I'm missing the free_irq() in error handling and the flexcan_close()
function. Please test your driver if it work still after several
modprobe rmmod cycles.

> +	}
> +
>  	flexcan_chip_interrupts_enable(dev);
>  
>  	can_led_event(dev, CAN_LED_EVENT_OPEN);
> @@ -2047,7 +2081,9 @@ static int flexcan_probe(struct platform_device *pdev)
>  	struct regulator *reg_xceiver;
>  	struct clk *clk_ipg = NULL, *clk_per = NULL;
>  	struct flexcan_regs __iomem *regs;
> +	struct mcf_flexcan_platform_data *pdata;
>  	int err, irq;
> +	bool big_endian_module;
>  	u8 clk_src = 1;
>  	u32 clock_freq = 0;
>  
> @@ -2059,11 +2095,17 @@ static int flexcan_probe(struct platform_device *pdev)
>  	else if (IS_ERR(reg_xceiver))
>  		return PTR_ERR(reg_xceiver);
>  
> -	if (pdev->dev.of_node) {
> -		of_property_read_u32(pdev->dev.of_node,
> -				     "clock-frequency", &clock_freq);
> -		of_property_read_u8(pdev->dev.of_node,
> -				    "fsl,clk-source", &clk_src);
> +	pdata = dev_get_platdata(&pdev->dev);
> +	if (pdata) {
> +		clock_freq = pdata->clock_frequency;
> +		clk_src = pdata->clk_src;
> +	} else {
> +		if (pdev->dev.of_node) {

else if

> +			of_property_read_u32(pdev->dev.of_node,
> +					     "clock-frequency", &clock_freq);
> +			of_property_read_u8(pdev->dev.of_node,
> +					    "fsl,clk-source", &clk_src);
> +		}
>  	}
>  
>  	if (!clock_freq) {
> @@ -2091,6 +2133,11 @@ static int flexcan_probe(struct platform_device *pdev)
>  
>  	devtype_data = of_device_get_match_data(&pdev->dev);
>  
> +	if (pdata && !devtype_data) {
> +		devtype_data =
> +			(struct flexcan_devtype_data *)&fsl_mcf_devtype_data;

That looks broken, see 2c0ac9208135 how to do this properly. Please add a
name "flexcan-mcf" to the id_table and use fsl_mcf_devtype_data as
driver_data.

> +	}
> +
>  	if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
>  	    !(devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)) {
>  		dev_err(&pdev->dev, "CAN-FD mode doesn't work with FIFO mode!\n");
> @@ -2110,8 +2157,11 @@ static int flexcan_probe(struct platform_device *pdev)
>  
>  	priv = netdev_priv(dev);
>  
> -	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
> -	    devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
> +	big_endian_module = pdata ? pdata->big_endian :
> +		of_property_read_bool(pdev->dev.of_node, "big-endian");

Please add the FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN to you
fsl_mcf_devtype_data if needed. There's no need to add a 3rd way of
configuring this.

> +
> +	if (big_endian_module ||
> +		(devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN)) {
>  		priv->read = flexcan_read_be;
>  		priv->write = flexcan_write_be;
>  	} else {
> -- 
> 2.31.1
> 
>

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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