Re: [PATCH v2] gpio / ACPI: Add label to the gpio request

From: Mika Westerberg
Date: Mon Jun 15 2015 - 11:36:37 EST

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On Mon, Jun 15, 2015 at 12:00:57AM +0200, Tobias Diedrich wrote:
> In leds-gpio.c create_gpio_led only the legacy path propagates the label
> by passing it into devm_gpio_request_one. Similarily gpio_keys_polled.c
> also neglects to propagate the name to the gpio subsystem.
>
> On the newer devicetree/acpi path the label is lost as far as the GPIO
> subsystem goes (it is only retained as name in struct gpio_led.
>
> Amend devm_get_gpiod_from_child to take an additonal (optional) label
^^^^^^^^^
additional

Also please spell ACPI consistently with capital letters.

> argument and propagate it so it will show up in /sys/kernel/debug/gpio.
>
> So instead of:
>
> GPIOs 288-511, platform/PRP0001:00, AMD SBX00:
> gpio-475 (? ) in hi
> gpio-477 (? ) out hi
> gpio-478 (? ) out lo
> gpio-479 (? ) out hi
>
> we get the much nicer output:
>
> GPIOs 288-511, platform/PRP0001:00, AMD SBX00:
> gpio-475 (switch1 ) in hi
> gpio-477 (led1 ) out hi
> gpio-478 (led2 ) out lo
> gpio-479 (led3 ) out hi

That is nicer, indeed :-)

> Signed-off-by: Tobias Diedrich <ranma+kernel@xxxxxxxxxxxx>
> ---
> drivers/gpio/devres.c | 6 ++++--
> drivers/gpio/gpiolib.c | 6 ++++--
> drivers/input/keyboard/gpio_keys_polled.c | 9 +++++----
> drivers/leds/leds-gpio.c | 20 +++++++++++---------
> include/linux/gpio/consumer.h | 6 ++++--
> 5 files changed, 28 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
> index 07ba823..40a6089 100644
> --- a/drivers/gpio/devres.c
> +++ b/drivers/gpio/devres.c
> @@ -127,13 +127,15 @@ EXPORT_SYMBOL(__devm_gpiod_get_index);
> * @dev: GPIO consumer
> * @con_id: function within the GPIO consumer
> * @child: firmware node (child of @dev)
> + * @label: a literal description string of this GPIO

It should say that this is optional and passing NULL is just as fine.

> *
> * GPIO descriptors returned from this function are automatically disposed on
> * driver detach.
> */
> struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> const char *con_id,
> - struct fwnode_handle *child)
> + struct fwnode_handle *child,
> + const char *label)
> {
> static const char * const suffixes[] = { "gpios", "gpio" };
> char prop_name[32]; /* 32 is max size of property name */
> @@ -154,7 +156,7 @@ struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> snprintf(prop_name, sizeof(prop_name), "%s",
> suffixes[i]);
>
> - desc = fwnode_get_named_gpiod(child, prop_name);
> + desc = fwnode_get_named_gpiod(child, prop_name, label);
> if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
> break;
> }
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 6bc612b..b3f2e5c 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -2017,6 +2017,7 @@ EXPORT_SYMBOL_GPL(__gpiod_get_index);
> * fwnode_get_named_gpiod - obtain a GPIO from firmware node
> * @fwnode: handle of the firmware node
> * @propname: name of the firmware property representing the GPIO
> + * @label: label for the GPIO

ditto.

Otherwise this is fine by me.

Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

> *
> * This function can be used for drivers that get their configuration
> * from firmware.
> @@ -2028,7 +2029,8 @@ EXPORT_SYMBOL_GPL(__gpiod_get_index);
> * In case of error an ERR_PTR() is returned.
> */
> struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
> - const char *propname)
> + const char *propname,
> + const char *label)
> {
> struct gpio_desc *desc = ERR_PTR(-ENODEV);
> bool active_low = false;
> @@ -2056,7 +2058,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
> if (IS_ERR(desc))
> return desc;
>
> - ret = gpiod_request(desc, NULL);
> + ret = gpiod_request(desc, label);
> if (ret)
> return ERR_PTR(ret);
>
> diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
> index 097d721..4cf3d23 100644
> --- a/drivers/input/keyboard/gpio_keys_polled.c
> +++ b/drivers/input/keyboard/gpio_keys_polled.c
> @@ -124,8 +124,12 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
>
> device_for_each_child_node(dev, child) {
> struct gpio_desc *desc;
> + button = &pdata->buttons[pdata->nbuttons++];
> +
> + fwnode_property_read_string(child, "label", &button->desc);
>
> - desc = devm_get_gpiod_from_child(dev, NULL, child);
> + desc = devm_get_gpiod_from_child(dev, NULL, child,
> + button->desc);
> if (IS_ERR(desc)) {
> error = PTR_ERR(desc);
> if (error != -EPROBE_DEFER)
> @@ -136,7 +140,6 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
> return ERR_PTR(error);
> }
>
> - button = &pdata->buttons[pdata->nbuttons++];
> button->gpiod = desc;
>
> if (fwnode_property_read_u32(child, "linux,code", &button->code)) {
> @@ -146,8 +149,6 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
> return ERR_PTR(-EINVAL);
> }
>
> - fwnode_property_read_string(child, "label", &button->desc);
> -
> if (fwnode_property_read_u32(child, "linux,input-type",
> &button->type))
> button->type = EV_KEY;
> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
> index 15eb3f8..082ad40 100644
> --- a/drivers/leds/leds-gpio.c
> +++ b/drivers/leds/leds-gpio.c
> @@ -184,13 +184,6 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
> struct gpio_led led = {};
> const char *state = NULL;
>
> - led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
> - if (IS_ERR(led.gpiod)) {
> - fwnode_handle_put(child);
> - ret = PTR_ERR(led.gpiod);
> - goto err;
> - }
> -
> np = of_node(child);
>
> if (fwnode_property_present(child, "label")) {
> @@ -198,9 +191,18 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
> } else {
> if (IS_ENABLED(CONFIG_OF) && !led.name && np)
> led.name = np->name;
> - if (!led.name)
> - return ERR_PTR(-EINVAL);
> }
> + if (!led.name)
> + return ERR_PTR(-EINVAL);
> +
> + led.gpiod = devm_get_gpiod_from_child(dev, NULL, child,
> + led.name);
> + if (IS_ERR(led.gpiod)) {
> + fwnode_handle_put(child);
> + ret = PTR_ERR(led.gpiod);
> + goto err;
> + }
> +
> fwnode_property_read_string(child, "linux,default-trigger",
> &led.default_trigger);
>
> diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
> index 3a7c9ff..51654cf 100644
> --- a/include/linux/gpio/consumer.h
> +++ b/include/linux/gpio/consumer.h
> @@ -134,10 +134,12 @@ int desc_to_gpio(const struct gpio_desc *desc);
> struct fwnode_handle;
>
> struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
> - const char *propname);
> + const char *propname,
> + const char *label);
> struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> const char *con_id,
> - struct fwnode_handle *child);
> + struct fwnode_handle *child,
> + const char *label);
> #else /* CONFIG_GPIOLIB */
>
> static inline int gpiod_count(struct device *dev, const char *con_id)
> --
> 2.1.4
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Next message: Peter Zijlstra: "Re: [PATCH 3/8] ARCv2: perf: implement "event_set_period" for future use with interrupts"
Previous message: Georgi Djakov: "Re: [PATCH 4/5] clk: qcom: Add A53 clock driver"
In reply to: Alexandre Courbot: "Re: [PATCH v2] gpio / ACPI: Add label to the gpio request"
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