Re: [PATCH 04/23] gpiolib: generalize devprop_gpiochip_set_names() for device properties

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, Sep 04, 2020 at 05:45:28PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> devprop_gpiochip_set_names() is overly complicated with taking the
> fwnode argument (which requires using dev_fwnode() & of_fwnode_handle()
> in ACPI and OF GPIO code respectively). Let's just switch to using the
> generic device properties.
> 
> This allows us to pull the code setting line names directly into
> gpiochip_add_data_with_key() instead of handling it separately for
> ACPI and OF.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/gpio/gpiolib-acpi.c    |  3 ---
>  drivers/gpio/gpiolib-devprop.c | 19 ++++++++++---------
>  drivers/gpio/gpiolib-of.c      |  5 -----
>  drivers/gpio/gpiolib.c         |  8 ++++----
>  include/linux/gpio/driver.h    |  3 +--
>  5 files changed, 15 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> index 54ca3c18b291..834a12f3219e 100644
> --- a/drivers/gpio/gpiolib-acpi.c
> +++ b/drivers/gpio/gpiolib-acpi.c
> @@ -1221,9 +1221,6 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
>  		return;
>  	}
>  
> -	if (!chip->names)
> -		devprop_gpiochip_set_names(chip, dev_fwnode(chip->parent));
> -
>  	acpi_gpiochip_request_regions(acpi_gpio);
>  	acpi_gpiochip_scan_gpios(acpi_gpio);
>  	acpi_walk_dep_device_list(handle);
> diff --git a/drivers/gpio/gpiolib-devprop.c b/drivers/gpio/gpiolib-devprop.c
> index 26741032fa9e..a28659b4f9c9 100644
> --- a/drivers/gpio/gpiolib-devprop.c
> +++ b/drivers/gpio/gpiolib-devprop.c
> @@ -17,25 +17,24 @@
>  /**
>   * devprop_gpiochip_set_names - Set GPIO line names using device properties
>   * @chip: GPIO chip whose lines should be named, if possible
> - * @fwnode: Property Node containing the gpio-line-names property
>   *
>   * Looks for device property "gpio-line-names" and if it exists assigns
>   * GPIO line names for the chip. The memory allocated for the assigned
> - * names belong to the underlying firmware node and should not be released
> + * names belong to the underlying software node and should not be released
>   * by the caller.
>   */
> -void devprop_gpiochip_set_names(struct gpio_chip *chip,
> -				const struct fwnode_handle *fwnode)
> +int devprop_gpiochip_set_names(struct gpio_chip *chip)
>  {
>  	struct gpio_device *gdev = chip->gpiodev;
> +	struct device *dev = chip->parent;
>  	const char **names;
>  	int ret, i;
>  	int count;
>  
> -	count = fwnode_property_read_string_array(fwnode, "gpio-line-names",
> +	count = device_property_read_string_array(dev, "gpio-line-names",
>  						  NULL, 0);
>  	if (count < 0)
> -		return;
> +		return 0;

Can we introduce a followup to 33ee09cd59ce ("device property: Add helpers to
count items in an array") for strings?

>  	if (count > gdev->ngpio) {
>  		dev_warn(&gdev->dev, "gpio-line-names is length %d but should be at most length %d",
> @@ -45,19 +44,21 @@ void devprop_gpiochip_set_names(struct gpio_chip *chip,
>  
>  	names = kcalloc(count, sizeof(*names), GFP_KERNEL);
>  	if (!names)
> -		return;
> +		return -ENOMEM;
>  
> -	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
> +	ret = device_property_read_string_array(dev, "gpio-line-names",
>  						names, count);
>  	if (ret < 0) {
>  		dev_warn(&gdev->dev, "failed to read GPIO line names\n");
>  		kfree(names);
> -		return;
> +		return ret;
>  	}
>  
>  	for (i = 0; i < count; i++)
>  		gdev->descs[i].name = names[i];
>  
>  	kfree(names);
> +
> +	return 0;
>  }
>  EXPORT_SYMBOL_GPL(devprop_gpiochip_set_names);
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index bd31dd3b6a75..2f895a2b8411 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -1026,11 +1026,6 @@ int of_gpiochip_add(struct gpio_chip *chip)
>  	if (ret)
>  		return ret;
>  
> -	/* If the chip defines names itself, these take precedence */
> -	if (!chip->names)
> -		devprop_gpiochip_set_names(chip,
> -					   of_fwnode_handle(chip->of_node));
> -
>  	of_node_get(chip->of_node);
>  
>  	ret = of_gpiochip_scan_gpios(chip);
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 80137c1b3cdc..0d390f0ec32c 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -340,9 +340,6 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
>  	struct gpio_device *gdev = gc->gpiodev;
>  	int i;
>  
> -	if (!gc->names)
> -		return 0;
> -
>  	/* First check all names if they are unique */
>  	for (i = 0; i != gc->ngpio; ++i) {
>  		struct gpio_desc *gpio;
> @@ -621,7 +618,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
>  	INIT_LIST_HEAD(&gdev->pin_ranges);
>  #endif
>  
> -	ret = gpiochip_set_desc_names(gc);
> +	if (gc->names)
> +		ret = gpiochip_set_desc_names(gc);
> +	else
> +		ret = devprop_gpiochip_set_names(gc);
>  	if (ret)
>  		goto err_remove_from_list;
>  
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index d1cef5c2715c..56485a040b82 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -756,8 +756,7 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
>  					    enum gpiod_flags dflags);
>  void gpiochip_free_own_desc(struct gpio_desc *desc);
>  
> -void devprop_gpiochip_set_names(struct gpio_chip *gc,
> -				const struct fwnode_handle *fwnode);
> +int devprop_gpiochip_set_names(struct gpio_chip *gc);
>  
>  #ifdef CONFIG_GPIOLIB
>  
> -- 
> 2.26.1
> 

-- 
With Best Regards,
Andy Shevchenko