Re: [PATCH 2/2] watchdog: max63xx_wdt: Add device tree probing

[Guenter Roeck <linux@roeck-us.net>]

On Wed, Jul 14, 2021 at 05:33:14PM +0200, Linus Walleij wrote:
> This adds device tree probing to the MAX63xx driver so it can be
> instantiated from the device tree. We use the generic fwnode-based
> method to get to the match data and clean up by constifying the
> functions as the match is indeed a const.
> 
> Cc: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/max63xx_wdt.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
> index 3a899628a834..9e1541cfae0d 100644
> --- a/drivers/watchdog/max63xx_wdt.c
> +++ b/drivers/watchdog/max63xx_wdt.c
> @@ -26,6 +26,7 @@
>  #include <linux/spinlock.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
> +#include <linux/property.h>
>  
>  #define DEFAULT_HEARTBEAT 60
>  #define MAX_HEARTBEAT     60
> @@ -99,8 +100,8 @@ static const struct max63xx_timeout max6373_table[] = {
>  	{ },
>  };
>  
> -static struct max63xx_timeout *
> -max63xx_select_timeout(struct max63xx_timeout *table, int value)
> +static const struct max63xx_timeout *
> +max63xx_select_timeout(const struct max63xx_timeout *table, int value)
>  {
>  	while (table->twd) {
>  		if (value <= table->twd) {
> @@ -202,14 +203,17 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct max63xx_wdt *wdt;
> -	struct max63xx_timeout *table;
> +	const struct max63xx_timeout *table;
>  	int err;
>  
>  	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
>  	if (!wdt)
>  		return -ENOMEM;
>  
> -	table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
> +	/* Attempt to use fwnode first */
> +	table = device_get_match_data(dev);
> +	if (!table)
> +		table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
>  
>  	if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
>  		heartbeat = DEFAULT_HEARTBEAT;
> @@ -255,11 +259,23 @@ static const struct platform_device_id max63xx_id_table[] = {
>  };
>  MODULE_DEVICE_TABLE(platform, max63xx_id_table);
>  
> +static const struct of_device_id max63xx_dt_id_table[] = {
> +	{ .compatible = "maxim,max6369", .data = max6369_table, },
> +	{ .compatible = "maxim,max6370", .data = max6369_table, },
> +	{ .compatible = "maxim,max6371", .data = max6371_table, },
> +	{ .compatible = "maxim,max6372", .data = max6371_table, },
> +	{ .compatible = "maxim,max6373", .data = max6373_table, },
> +	{ .compatible = "maxim,max6374", .data = max6373_table, },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, max63xx_dt_id_table);
> +
>  static struct platform_driver max63xx_wdt_driver = {
>  	.probe		= max63xx_wdt_probe,
>  	.id_table	= max63xx_id_table,
>  	.driver		= {
>  		.name	= "max63xx_wdt",
> +		.of_match_table = max63xx_dt_id_table,
>  	},
>  };
>  
> -- 
> 2.31.1
>