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Message-ID: <ec5531e5-6fae-431e-bc58-73bb816d477d@189.cn>
Date: Thu, 2 Jan 2025 09:25:53 +0800
From: Song Chen <chensong_2000@....cn>
To: brgl@...ev.pl, linus.walleij@...aro.org, corbet@....net
Cc: linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
linux-doc@...r.kernel.org
Subject: Re: [PATCH RFC] drivers:gpio: introduce variants of gpiod_get_array
Dear maintainers,
It has been a while after this patch was sent. I'm not sure if i
followed the idea suggested by Bart correctly, see [1], any comment will
be appreciated.
Best regards,
Song
[1]:https://lore.kernel.org/lkml/CAMRc=MfpwuMh-MH1UEHKky09iAs4g9=iGFPptARXzoZrVS8hdQ@mail.gmail.com/
在 2024/12/17 16:53, Song Chen 写道:
> This patch introduces another two variants of gpiod_get_array,
> fwnode_gpiod_get_array and devm_fwnode_gpiod_get_array, to
> return GPIO descriptor array to comsumers.
>
> Unlike gpiod_get_array, which calls dev_fwnode(dev) to get
> firmware node in gpiod_get_index, new variants allow consumers
> to pass firmware node by themselves.
>
> It's applicable to below circumstance:
>
> fwnode_for_each_child_node(fw_parent, fw_child)
> or for_each_child_of_node
> struct gpio_descs *array = devm_fwnode_gpiod_get_array(
> dev, fw_child,...).
> or fwnode_gpiod_get_array
>
> Signed-off-by: Song Chen <chensong_2000@....cn>
> ---
> drivers/gpio/gpiolib-devres.c | 43 ++++++++++++++++
> drivers/gpio/gpiolib.c | 96 +++++++++++++++++++++++++++++------
> include/linux/gpio/consumer.h | 28 ++++++++++
> 3 files changed, 151 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
> index 08205f355ceb..f8b2a3fe02ba 100644
> --- a/drivers/gpio/gpiolib-devres.c
> +++ b/drivers/gpio/gpiolib-devres.c
> @@ -192,6 +192,49 @@ struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
> }
> EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_index);
>
> +/**
> + * devm_fwnode_gpiod_get_array - Resource-managed gpiod_get_array_by_fwnode()
> + * @dev: GPIO consumer
> + * @fwnode: firmware node containing GPIO reference
> + * @con_id: function within the GPIO consumer
> + * @flags: optional GPIO initialization flags
> + *
> + * Managed gpiod_get_array_by_fwnode(). GPIO descriptors returned from this function are
> + * automatically disposed on driver detach. See gpiod_get_array_by_fwnode() for detailed
> + * information about behavior and return values.
> + *
> + * Returns:
> + * The GPIO descriptors corresponding to the function @con_id of device
> + * dev, %-ENOENT if no GPIO has been assigned to the requested function,
> + * or another IS_ERR() code if an error occurred while trying to acquire
> + * the GPIOs.
> + */
> +struct gpio_descs *devm_fwnode_gpiod_get_array(struct device *dev,
> + struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + struct gpio_descs **dr;
> + struct gpio_descs *descs;
> +
> + dr = devres_alloc(devm_gpiod_release_array,
> + sizeof(struct gpio_descs *), GFP_KERNEL);
> + if (!dr)
> + return ERR_PTR(-ENOMEM);
> +
> + descs = gpiod_get_array_by_fwnode(dev, fwnode, con_id, flags);
> + if (IS_ERR(descs)) {
> + devres_free(dr);
> + return descs;
> + }
> +
> + *dr = descs;
> + devres_add(dev, dr);
> +
> + return descs;
> +}
> +EXPORT_SYMBOL_GPL(devm_fwnode_gpiod_get_array);
> +
> /**
> * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
> * @dev: GPIO consumer
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 679ed764cb14..dbb39e6bb568 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -4469,6 +4469,33 @@ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
> }
> EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
>
> +/**
> + * fwnode_gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
> + * @fwnode: handle of the firmware node
> + * @con_id: function within the GPIO consumer
> + * @flags: GPIO initialization flags
> + *
> + * This function can be used for drivers that get their configuration
> + * from opaque firmware.
> + *
> + * The function properly finds the corresponding GPIOs using whatever is the
> + * underlying firmware interface and then makes sure that the GPIO
> + * descriptors are requested before they are returned to the caller.
> + *
> + * Returns:
> + * On successful request the GPIO descriptors are configured in accordance with
> + * provided @flags.
> + *
> + * In case of error an ERR_PTR() is returned.
> + */
> +struct gpio_descs *fwnode_gpiod_get_array(struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + return gpiod_get_array_by_fwnode(NULL, fwnode, con_id, flags);
> +}
> +EXPORT_SYMBOL_GPL(fwnode_gpiod_get_array);
> +
> /**
> * gpiod_count - return the number of GPIOs associated with a device / function
> * @dev: GPIO consumer, can be NULL for system-global GPIOs
> @@ -4731,21 +4758,8 @@ static void gpiochip_free_hogs(struct gpio_chip *gc)
> gpiochip_free_own_desc(desc);
> }
>
> -/**
> - * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
> - * @dev: GPIO consumer, can be NULL for system-global GPIOs
> - * @con_id: function within the GPIO consumer
> - * @flags: optional GPIO initialization flags
> - *
> - * This function acquires all the GPIOs defined under a given function.
> - *
> - * Returns:
> - * The GPIO descriptors corresponding to the function @con_id of device
> - * dev, -ENOENT if no GPIO has been assigned to the requested function,
> - * or another IS_ERR() code if an error occurred while trying to acquire
> - * the GPIOs.
> - */
> -struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
> +static struct gpio_descs *__gpiod_get_array(struct device *dev,
> + struct fwnode_handle *fwnode,
> const char *con_id,
> enum gpiod_flags flags)
> {
> @@ -4766,7 +4780,12 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
> return ERR_PTR(-ENOMEM);
>
> for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
> - desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
> + if (fwnode)
> + desc = gpiod_find_and_request(dev, fwnode, con_id, descs->ndescs,
> + flags, NULL, false);
> + else
> + desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
> +
> if (IS_ERR(desc)) {
> gpiod_put_array(descs);
> return ERR_CAST(desc);
> @@ -4858,8 +4877,53 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
> *array_info->invert_mask);
> return descs;
> }
> +
> +/**
> + * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
> + * @dev: GPIO consumer, can be NULL for system-global GPIOs
> + * @con_id: function within the GPIO consumer
> + * @flags: optional GPIO initialization flags
> + *
> + * This function acquires all the GPIOs defined under a given function.
> + *
> + * Returns:
> + * The GPIO descriptors corresponding to the function @con_id of device
> + * dev, -ENOENT if no GPIO has been assigned to the requested function,
> + * or another IS_ERR() code if an error occurred while trying to acquire
> + * the GPIOs.
> + */
> +struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + return __gpiod_get_array(dev, NULL, con_id, flags);
> +}
> EXPORT_SYMBOL_GPL(gpiod_get_array);
>
> +/**
> + * gpiod_get_array_by_fwnode - obtain multiple GPIOs from a multi-index GPIO function
> + * @dev: GPIO consumer, can be NULL for system-global GPIOs
> + * @fwnode: Firmware node to lookup
> + * @con_id: function within the GPIO consumer
> + * @flags: optional GPIO initialization flags
> + *
> + * This function acquires all the GPIOs defined under a given function.
> + *
> + * Returns:
> + * The GPIO descriptors corresponding to the function @con_id of device
> + * dev, -ENOENT if no GPIO has been assigned to the requested function,
> + * or another IS_ERR() code if an error occurred while trying to acquire
> + * the GPIOs.
> + */
> +struct gpio_descs *__must_check gpiod_get_array_by_fwnode(struct device *dev,
> + struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + return __gpiod_get_array(dev, fwnode, con_id, flags);
> +}
> +EXPORT_SYMBOL_GPL(gpiod_get_array_by_fwnode);
> +
> /**
> * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
> * function
> diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
> index db2dfbae8edb..7143bf7045ce 100644
> --- a/include/linux/gpio/consumer.h
> +++ b/include/linux/gpio/consumer.h
> @@ -80,6 +80,10 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
> struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
> const char *con_id,
> enum gpiod_flags flags);
> +struct gpio_descs *__must_check gpiod_get_array_by_fwnode(struct device *dev,
> + struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags);
> void gpiod_put(struct gpio_desc *desc);
> void gpiod_put_array(struct gpio_descs *descs);
>
> @@ -175,11 +179,18 @@ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
> const char *con_id, int index,
> enum gpiod_flags flags,
> const char *label);
> +struct gpio_descs *fwnode_gpiod_get_array(struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags);
> struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
> struct fwnode_handle *child,
> const char *con_id, int index,
> enum gpiod_flags flags,
> const char *label);
> +struct gpio_descs *devm_fwnode_gpiod_get_array(struct device *dev,
> + struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags);
>
> #else /* CONFIG_GPIOLIB */
>
> @@ -548,6 +559,14 @@ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
> return ERR_PTR(-ENOSYS);
> }
>
> +static inline
> +struct gpio_descs *fwnode_gpiod_get_array(struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> static inline
> struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
> struct fwnode_handle *fwnode,
> @@ -558,6 +577,15 @@ struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
> return ERR_PTR(-ENOSYS);
> }
>
> +static inline
> +struct gpio_descs *devm_fwnode_gpiod_get_array(struct device *dev,
> + struct fwnode_handle *fwnode,
> + const char *con_id,
> + enum gpiod_flags flags)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> #endif /* CONFIG_GPIOLIB */
>
> static inline
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