Hi Alexander,
Sorry, this isn't going to be a complete review, just a couple of
comments.
On Sun, 23 Feb 2014, Alexander Shiyan wrote:
> This is a RFC patch only, please do not apply it.
>
> This introduce a conversion slot-gpio to gpiod-* API.
> Usage of gpiod-* API allows us to remove all pieces of storage
> GPIOs in the driver's platform_data in the future.
> Patch saves calls to existing functions that allows us to convert
> all drivers to use new interface, one by one.
> Ready for comments and suggestions.
> ---
> drivers/mmc/core/slot-gpio.c | 221
> ++++++++++++++++++++++++++----------------
> include/linux/mmc/slot-gpio.h | 10 +-
> 2 files changed, 148 insertions(+), 83 deletions(-)
>
> diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
> index 46596b71..6fc0483 100644
> --- a/drivers/mmc/core/slot-gpio.c
> +++ b/drivers/mmc/core/slot-gpio.c
> @@ -14,17 +14,14 @@
> #include <linux/jiffies.h>
> #include <linux/mmc/host.h>
> #include <linux/mmc/slot-gpio.h>
> -#include <linux/module.h>
> -#include <linux/slab.h>
>
> struct mmc_gpio {
> - int ro_gpio;
> - int cd_gpio;
> - char *ro_label;
> - char cd_label[0];
> + struct gpio_desc *ro_gpio;
> + struct gpio_desc *cd_gpio;
> + char *cd_label;
First question: has this patch been run-time tested? I don't see the above
cd_label being assigned anywhere.
> };
>
> -static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
> +static irqreturn_t mmc_gpio_cd_irq(int irq, void *dev_id)
> {
> /* Schedule a card detection after a debounce timeout */
> struct mmc_host *host = dev_id;
> @@ -37,34 +34,26 @@ static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> -static int mmc_gpio_alloc(struct mmc_host *host)
> +static int mmc_gpiod_alloc(struct mmc_host *host)
> {
> size_t len = strlen(dev_name(host->parent)) + 4;
> - struct mmc_gpio *ctx;
> -
> - mutex_lock(&host->slot.lock);
Why do you decide to remove mutex locking? This is an unrelated change.
> + struct mmc_gpio *ctx = host->slot.handler_priv;
>
> - ctx = host->slot.handler_priv;
> if (!ctx) {
> /*
> * devm_kzalloc() can be called after device_initialize(), even
> * before device_add(), i.e., between mmc_alloc_host() and
> * mmc_add_host()
> */
> - ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
> + ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + len,
> GFP_KERNEL);
> if (ctx) {
> - ctx->ro_label = ctx->cd_label + len;
> - snprintf(ctx->cd_label, len, "%s cd",
> dev_name(host->parent));
> - snprintf(ctx->ro_label, len, "%s ro",
> dev_name(host->parent));
> - ctx->cd_gpio = -EINVAL;
> - ctx->ro_gpio = -EINVAL;
> + snprintf(ctx->cd_label, len, "%s cd",
> + dev_name(host->parent));
> host->slot.handler_priv = ctx;
> }
> }
>
> - mutex_unlock(&host->slot.lock);
> -
> return ctx ? 0 : -ENOMEM;
> }
>
> @@ -72,10 +61,10 @@ int mmc_gpio_get_ro(struct mmc_host *host)
> {
> struct mmc_gpio *ctx = host->slot.handler_priv;
>
> - if (!ctx || !gpio_is_valid(ctx->ro_gpio))
> + if (!ctx || IS_ERR_OR_NULL(ctx->ro_gpio))
> return -ENOSYS;
>
> - return !gpio_get_value_cansleep(ctx->ro_gpio) ^
> + return !gpiod_get_value_cansleep(ctx->ro_gpio) ^
> !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
> }
> EXPORT_SYMBOL(mmc_gpio_get_ro);
> @@ -84,18 +73,17 @@ int mmc_gpio_get_cd(struct mmc_host *host)
> {
> struct mmc_gpio *ctx = host->slot.handler_priv;
>
> - if (!ctx || !gpio_is_valid(ctx->cd_gpio))
> + if (!ctx || IS_ERR_OR_NULL(ctx->cd_gpio))
> return -ENOSYS;
>
> - return !gpio_get_value_cansleep(ctx->cd_gpio) ^
> + return !gpiod_get_value_cansleep(ctx->cd_gpio) ^
> !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
> }
> EXPORT_SYMBOL(mmc_gpio_get_cd);
>
> /**
> - * mmc_gpio_request_ro - request a gpio for write-protection
> + * mmc_gpiod_request_ro - request a gpio for write-protection
> * @host: mmc host
> - * @gpio: gpio number requested
> *
> * As devm_* managed functions are used in mmc_gpio_request_ro(), client
> * drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up,
> @@ -106,35 +94,45 @@ EXPORT_SYMBOL(mmc_gpio_get_cd);
> *
> * Returns zero on success, else an error.
> */
> -int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
> +int mmc_gpiod_request_ro(struct mmc_host *host)
> {
> - struct mmc_gpio *ctx;
> + struct mmc_gpio *ctx = host->slot.handler_priv;
> int ret;
>
> - if (!gpio_is_valid(gpio))
> - return -EINVAL;
> -
> - ret = mmc_gpio_alloc(host);
> - if (ret < 0)
> + ret = mmc_gpiod_alloc(host);
> + if (ret)
> return ret;
>
> - ctx = host->slot.handler_priv;
> + ctx->ro_gpio = devm_gpiod_get(&host->class_dev, "wp");
> + if (IS_ERR(ctx->ro_gpio))
> + return PTR_ERR(ctx->ro_gpio);
> +
> + return gpiod_direction_input(ctx->ro_gpio);
> +}
> +EXPORT_SYMBOL(mmc_gpiod_request_ro);
> +
> +int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
> +{
> + struct mmc_gpio *ctx = host->slot.handler_priv;
> + int ret;
> +
> + ret = mmc_gpiod_alloc(host);
> + if (ret)
> + return ret;
>
> - ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
> - ctx->ro_label);
> - if (ret < 0)
> + ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_IN, "wp");
> + if (ret)
I consider the choice of "if (ret)" vs. "if (ret < 0)" mostly a matter of
taste / style and I prefer to keep this uniform across sources. If you
really think this is important, please, submit a separate patch.
> return ret;
Wouldn't this change break platforms, that already have MMC GPIOs with the
old style label? Why do you have to change this?
Thanks
Guennadi
>
> - ctx->ro_gpio = gpio;
> + ctx->ro_gpio = gpio_to_desc(gpio);
>
> - return 0;
> + return IS_ERR(ctx->ro_gpio) ? PTR_ERR(ctx->ro_gpio) : 0;
> }
> EXPORT_SYMBOL(mmc_gpio_request_ro);
>
> /**
> - * mmc_gpio_request_cd - request a gpio for card-detection
> + * mmc_gpiod_request_cd - request a gpio for card-detection
> * @host: mmc host
> - * @gpio: gpio number requested
> * @debounce: debounce time in microseconds
> *
> * As devm_* managed functions are used in mmc_gpio_request_cd(), client
> @@ -150,60 +148,98 @@ EXPORT_SYMBOL(mmc_gpio_request_ro);
> *
> * Returns zero on success, else an error.
> */
> -int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
> - unsigned int debounce)
> +int mmc_gpiod_request_cd(struct mmc_host *host, unsigned int debounce)
> {
> - struct mmc_gpio *ctx;
> - int irq = gpio_to_irq(gpio);
> + struct mmc_gpio *ctx = host->slot.handler_priv;
> int ret;
>
> - ret = mmc_gpio_alloc(host);
> - if (ret < 0)
> + ret = mmc_gpiod_alloc(host);
> + if (ret)
> return ret;
>
> - ctx = host->slot.handler_priv;
> + ctx->cd_gpio = devm_gpiod_get(&host->class_dev, "cd");
> + if (IS_ERR(ctx->cd_gpio))
> + return PTR_ERR(ctx->cd_gpio);
>
> - ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN,
> - ctx->cd_label);
> - if (ret < 0)
> - /*
> - * don't bother freeing memory. It might still get used by other
> - * slot functions, in any case it will be freed, when the device
> - * is destroyed.
> - */
> + ret = gpiod_direction_input(ctx->cd_gpio);
> + if (ret)
> return ret;
>
> if (debounce) {
> - ret = gpio_set_debounce(gpio, debounce);
> - if (ret < 0)
> + ret = gpiod_set_debounce(ctx->cd_gpio, debounce);
> + if (ret)
> return ret;
> }
>
> /*
> - * Even if gpio_to_irq() returns a valid IRQ number, the platform might
> + * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
> * still prefer to poll, e.g., because that IRQ number is already used
> * by another unit and cannot be shared.
> */
> - if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL)
> - irq = -EINVAL;
> -
> - if (irq >= 0) {
> - ret = devm_request_threaded_irq(&host->class_dev, irq,
> - NULL, mmc_gpio_cd_irqt,
> + if (!(host->caps & MMC_CAP_NEEDS_POLL)) {
> + host->slot.cd_irq = gpiod_to_irq(ctx->cd_gpio);
> + ret = devm_request_threaded_irq(&host->class_dev,
> + host->slot.cd_irq, NULL, mmc_gpio_cd_irq,
> IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
> IRQF_ONESHOT,
> ctx->cd_label, host);
> - if (ret < 0)
> - irq = ret;
> + if (ret)
> + host->slot.cd_irq = ret;
> + } else {
> + host->slot.cd_irq = -EINVAL;
> }
>
> - host->slot.cd_irq = irq;
> -
> - if (irq < 0)
> + if (host->slot.cd_irq < 0)
> host->caps |= MMC_CAP_NEEDS_POLL;
>
> - ctx->cd_gpio = gpio;
> + return ret;
> +}
> +EXPORT_SYMBOL(mmc_gpiod_request_cd);
> +
> +int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
> + unsigned int debounce)
> +{
> + struct mmc_gpio *ctx = host->slot.handler_priv;
> + int ret;
> +
> + ret = mmc_gpiod_alloc(host);
> + if (ret)
> + return ret;
>
> - return 0;
> + ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_IN, "cd");
> + if (ret)
> + return ret;
> +
> + ctx->cd_gpio = gpio_to_desc(gpio);
> + if (IS_ERR(ctx->cd_gpio))
> + return PTR_ERR(ctx->cd_gpio);
> +
> + if (debounce) {
> + ret = gpiod_set_debounce(ctx->cd_gpio, debounce);
> + if (ret)
> + return ret;
> + }
> +
> + /*
> + * Even if gpiod_to_irq() returns a valid IRQ number, the platform might
> + * still prefer to poll, e.g., because that IRQ number is already used
> + * by another unit and cannot be shared.
> + */
> + if (!(host->caps & MMC_CAP_NEEDS_POLL)) {
> + host->slot.cd_irq = gpiod_to_irq(ctx->cd_gpio);
> + ret = devm_request_threaded_irq(&host->class_dev,
> + host->slot.cd_irq, NULL, mmc_gpio_cd_irq,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
> IRQF_ONESHOT,
> + ctx->cd_label, host);
> + if (ret)
> + host->slot.cd_irq = ret;
> + } else {
> + host->slot.cd_irq = -EINVAL;
> + }
> +
> + if (host->slot.cd_irq < 0)
> + host->caps |= MMC_CAP_NEEDS_POLL;
> +
> + return ret;
> }
> EXPORT_SYMBOL(mmc_gpio_request_cd);
>
> @@ -214,18 +250,41 @@ EXPORT_SYMBOL(mmc_gpio_request_cd);
> * It's provided only for cases that client drivers need to manually free
> * up the write-protection gpio requested by mmc_gpio_request_ro().
> */
> +void mmc_gpiod_free(struct mmc_host *host)
> +{
> + struct mmc_gpio *ctx = host->slot.handler_priv;
> +
> + if (!ctx)
> + return;
> +
> + if (!IS_ERR_OR_NULL(ctx->ro_gpio))
> + devm_gpiod_put(&host->class_dev, ctx->ro_gpio);
> +
> + if (!IS_ERR_OR_NULL(ctx->cd_gpio)) {
> + if (host->slot.cd_irq >= 0) {
> + devm_free_irq(&host->class_dev, host->slot.cd_irq,
> host);
> + host->slot.cd_irq = -EINVAL;
> + }
> +
> + devm_gpiod_put(&host->class_dev, ctx->cd_gpio);
> + }
> +
> + devm_kfree(&host->class_dev, ctx);
> +
> + ctx = NULL;
> +}
> +EXPORT_SYMBOL(mmc_gpiod_free);
> +
> void mmc_gpio_free_ro(struct mmc_host *host)
> {
> struct mmc_gpio *ctx = host->slot.handler_priv;
> - int gpio;
>
> - if (!ctx || !gpio_is_valid(ctx->ro_gpio))
> + if (!ctx || IS_ERR_OR_NULL(ctx->ro_gpio))
> return;
>
> - gpio = ctx->ro_gpio;
> - ctx->ro_gpio = -EINVAL;
> + devm_gpiod_put(&host->class_dev, ctx->ro_gpio);
>
> - devm_gpio_free(&host->class_dev, gpio);
> + ctx->ro_gpio = NULL;
> }
> EXPORT_SYMBOL(mmc_gpio_free_ro);
>
> @@ -239,9 +298,8 @@ EXPORT_SYMBOL(mmc_gpio_free_ro);
> void mmc_gpio_free_cd(struct mmc_host *host)
> {
> struct mmc_gpio *ctx = host->slot.handler_priv;
> - int gpio;
>
> - if (!ctx || !gpio_is_valid(ctx->cd_gpio))
> + if (!ctx || IS_ERR_OR_NULL(ctx->cd_gpio))
> return;
>
> if (host->slot.cd_irq >= 0) {
> @@ -249,9 +307,8 @@ void mmc_gpio_free_cd(struct mmc_host *host)
> host->slot.cd_irq = -EINVAL;
> }
>
> - gpio = ctx->cd_gpio;
> - ctx->cd_gpio = -EINVAL;
> + devm_gpiod_put(&host->class_dev, ctx->cd_gpio);
>
> - devm_gpio_free(&host->class_dev, gpio);
> + ctx->cd_gpio = NULL;
> }
> EXPORT_SYMBOL(mmc_gpio_free_cd);
> diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
> index b0c73e4..a31ed96 100644
> --- a/include/linux/mmc/slot-gpio.h
> +++ b/include/linux/mmc/slot-gpio.h
> @@ -14,10 +14,18 @@
> struct mmc_host;
>
> int mmc_gpio_get_ro(struct mmc_host *host);
> +#define mmc_gpiod_get_ro(host) mmc_gpio_get_ro(host)
> +int mmc_gpiod_request_ro(struct mmc_host *host);
> +
> +int mmc_gpio_get_cd(struct mmc_host *host);
> +#define mmc_gpiod_get_cd(host) mmc_gpio_get_cd(host)
> +int mmc_gpiod_request_cd(struct mmc_host *host, unsigned int debounce);
> +
> +void mmc_gpiod_free(struct mmc_host *host);
> +
> int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio);
> void mmc_gpio_free_ro(struct mmc_host *host);
>
> -int mmc_gpio_get_cd(struct mmc_host *host);
> int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
> unsigned int debounce);
> void mmc_gpio_free_cd(struct mmc_host *host);
> --
> 1.8.3.2
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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