Re: [PATCH 1/3] mmc: core: Allow host driver to provide isr for card-detect interrupts.

Ulf Hansson
2014-12-30T11:08:39Z

On 24 December 2014 at 22:20, NeilBrown <neilb@suse.de> wrote:
> One of the reasons omap_hsmmc doesn't use the slot-gpio library
> is that it has some non-standard functionality in the card-detect
> interrupt service routine.
>
> To make it possible for omap_hsmmc (and maybe others) to be converted
> to use slot-gpio, add 'mmc_gpio_set_cd_isr' which provides an
> alternate isr to be registered by the slot-gpio code.
>
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
> drivers/mmc/core/slot-gpio.c | 20 +++++++++++++++++++-
> include/linux/mmc/slot-gpio.h | 2 ++
> 2 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
> index 1a3edbd47719..1826b25a2a40 100644
> --- a/drivers/mmc/core/slot-gpio.c
> +++ b/drivers/mmc/core/slot-gpio.c
> @@ -25,6 +25,7 @@ struct mmc_gpio {
> struct gpio_desc *cd_gpio;
> bool override_ro_active_level;
> bool override_cd_active_level;
> + irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
> char *ro_label;
> char cd_label[0];
> };
> @@ -136,8 +137,10 @@ void mmc_gpiod_request_cd_irq(struct mmc_host *host)
> irq = -EINVAL;
>
> if (irq >= 0) {
> + if (!ctx->cd_gpio_isr)
> + ctx->cd_gpio_isr = mmc_gpio_cd_irqt;
> ret = devm_request_threaded_irq(host->parent, irq,
> - NULL, mmc_gpio_cd_irqt,
> + NULL, ctx->cd_gpio_isr,
> IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> ctx->cd_label, host);
> if (ret < 0)
> @@ -151,6 +154,21 @@ void mmc_gpiod_request_cd_irq(struct mmc_host *host)
> }
> EXPORT_SYMBOL(mmc_gpiod_request_cd_irq);
>
> +/* Register an alternate interrupt service routine for
> + * the card-detect GPIO.
> + */
> +int mmc_gpio_set_cd_isr(struct mmc_host *host,
> + irqreturn_t (*isr)(int irq, void *dev_id))
> +{
> + struct mmc_gpio *ctx;
> +
> + ctx = host->slot.handler_priv;
> + if (ctx->cd_gpio_isr)
> + return -EBUSY;
> + ctx->cd_gpio_isr = isr;
> + return 0;

I feel this is a bit more complex than what's needed.
How about just assigning ->cd_gpio_isr() callback, without checking
it's value first and then make mmc_gpio_set_cd_isr() a void function?

> +}
> +
> /**
> * mmc_gpio_request_cd - request a gpio for card-detection
> * @host: mmc host
> diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
> index 4a36d6954631..4faf41c9a77a 100644
> --- a/include/linux/mmc/slot-gpio.h
> +++ b/include/linux/mmc/slot-gpio.h
> @@ -26,6 +26,8 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id,
> int mmc_gpiod_request_ro(struct mmc_host *host, const char *con_id,
> unsigned int idx, bool override_active_level,
> unsigned int debounce, bool *gpio_invert);
> +int mmc_gpio_set_cd_isr(struct mmc_host *host,
> + irqreturn_t (*isr)(int irq, void *dev_id));
> void mmc_gpiod_request_cd_irq(struct mmc_host *host);
>
> #endif
>
>