Re: [PATCH 1/6] mmc: slot-gpio: Record GPIO descriptors instead of GPIO numbers

[Adrian Hunter <adrian.hunter@intel.com>]

On 13.03.2014 15:00, Jaehoon Chung wrote:
> Dear Adrain.
> 
> I have tested with your patch-set related slot-gpio.
> It's working fine. And looks good to me.
> 
> I have a question. what's override_cd/ro_active_level?
> I didn't fully understand this value. Could you explain to me, plz?

The gpio descriptor records whether the gpio is active high or active low.
When using gpiod_get_value_cansleep() the value is inverted on that basis.
When using gpiod_get_raw_value_cansleep() the value is not inverted.

The legacy GPIO API did not record active low/high.  So then we use
gpiod_get_raw_value_cansleep().  The new API should be able to use
gpiod_get_value_cansleep().

In addition, for the device that I have the active high/low
information passed by ACPI is wrong anyway, so I also have to use the
override flag.


> 
> Best Regards,
> Jaehoon Chung
> 
> On 03/10/2014 10:02 PM, Adrian Hunter wrote:
>> In preparation for adding a descriptor-based CD GPIO
>> API, switch from recording GPIO numbers to recording
>> GPIO descriptors.
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>  drivers/mmc/core/slot-gpio.c | 45 ++++++++++++++++++++++++++------------------
>>  1 file changed, 27 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
>> index 46596b71..86547a2 100644
>> --- a/drivers/mmc/core/slot-gpio.c
>> +++ b/drivers/mmc/core/slot-gpio.c
>> @@ -10,6 +10,7 @@
>>  
>>  #include <linux/err.h>
>>  #include <linux/gpio.h>
>> +#include <linux/gpio/consumer.h>
>>  #include <linux/interrupt.h>
>>  #include <linux/jiffies.h>
>>  #include <linux/mmc/host.h>
>> @@ -18,8 +19,10 @@
>>  #include <linux/slab.h>
>>  
>>  struct mmc_gpio {
>> -	int ro_gpio;
>> -	int cd_gpio;
>> +	struct gpio_desc *ro_gpio;
>> +	struct gpio_desc *cd_gpio;
>> +	bool override_ro_active_level;
>> +	bool override_cd_active_level;
>>  	char *ro_label;
>>  	char cd_label[0];
>>  };
>> @@ -57,8 +60,6 @@ static int mmc_gpio_alloc(struct mmc_host *host)
>>  			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;
>>  			host->slot.handler_priv = ctx;
>>  		}
>>  	}
>> @@ -72,11 +73,14 @@ 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 || !ctx->ro_gpio)
>>  		return -ENOSYS;
>>  
>> -	return !gpio_get_value_cansleep(ctx->ro_gpio) ^
>> -		!!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
>> +	if (ctx->override_ro_active_level)
>> +		return !gpiod_get_raw_value_cansleep(ctx->ro_gpio) ^
>> +			!!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
>> +
>> +	return gpiod_get_value_cansleep(ctx->ro_gpio);
>>  }
>>  EXPORT_SYMBOL(mmc_gpio_get_ro);
>>  
>> @@ -84,11 +88,14 @@ 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 || !ctx->cd_gpio)
>>  		return -ENOSYS;
>>  
>> -	return !gpio_get_value_cansleep(ctx->cd_gpio) ^
>> -		!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
>> +	if (ctx->override_cd_active_level)
>> +		return !gpiod_get_raw_value_cansleep(ctx->cd_gpio) ^
>> +			!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
>> +
>> +	return gpiod_get_value_cansleep(ctx->cd_gpio);
>>  }
>>  EXPORT_SYMBOL(mmc_gpio_get_cd);
>>  
>> @@ -125,7 +132,8 @@ int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
>>  	if (ret < 0)
>>  		return ret;
>>  
>> -	ctx->ro_gpio = gpio;
>> +	ctx->override_ro_active_level = true;
>> +	ctx->ro_gpio = gpio_to_desc(gpio);
>>  
>>  	return 0;
>>  }
>> @@ -201,7 +209,8 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
>>  	if (irq < 0)
>>  		host->caps |= MMC_CAP_NEEDS_POLL;
>>  
>> -	ctx->cd_gpio = gpio;
>> +	ctx->override_cd_active_level = true;
>> +	ctx->cd_gpio = gpio_to_desc(gpio);
>>  
>>  	return 0;
>>  }
>> @@ -219,11 +228,11 @@ 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 || !ctx->ro_gpio)
>>  		return;
>>  
>> -	gpio = ctx->ro_gpio;
>> -	ctx->ro_gpio = -EINVAL;
>> +	gpio = desc_to_gpio(ctx->ro_gpio);
>> +	ctx->ro_gpio = NULL;
>>  
>>  	devm_gpio_free(&host->class_dev, gpio);
>>  }
>> @@ -241,7 +250,7 @@ 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 || !ctx->cd_gpio)
>>  		return;
>>  
>>  	if (host->slot.cd_irq >= 0) {
>> @@ -249,8 +258,8 @@ void mmc_gpio_free_cd(struct mmc_host *host)
>>  		host->slot.cd_irq = -EINVAL;
>>  	}
>>  
>> -	gpio = ctx->cd_gpio;
>> -	ctx->cd_gpio = -EINVAL;
>> +	gpio = desc_to_gpio(ctx->cd_gpio);
>> +	ctx->cd_gpio = NULL;
>>  
>>  	devm_gpio_free(&host->class_dev, gpio);
>>  }
>>
> 
> 
>