Re: [PATCH v2 5/5] misc: eeprom_93xx46: Add support for a GPIO 'select' line.

[Vladimir Zapolskiy <vz@mleia.com>]

On 19.11.2015 05:29, Cory Tusar wrote:
> This commit adds support to the eeprom_93x46 driver allowing a GPIO line
> to function as a 'select' or 'enable' signal prior to accessing the
> EEPROM.
> 
> Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
> ---
>  drivers/misc/eeprom/eeprom_93xx46.c | 26 ++++++++++++++++++++++++++
>  include/linux/eeprom_93xx46.h       |  1 +
>  2 files changed, 27 insertions(+)
> 
> diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
> index 0386b03..375951f 100644
> --- a/drivers/misc/eeprom/eeprom_93xx46.c
> +++ b/drivers/misc/eeprom/eeprom_93xx46.c
> @@ -10,11 +10,14 @@
>  
>  #include <linux/delay.h>
>  #include <linux/device.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/mutex.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/of_gpio.h>

Please double check, adding only linux/of_gpio.h header should work,
linux/gpio.h and linux/gpio/consumer.h are redundant.

>  #include <linux/slab.h>
>  #include <linux/spi/spi.h>
>  #include <linux/sysfs.h>
> @@ -344,6 +347,20 @@ static ssize_t eeprom_93xx46_store_erase(struct device *dev,
>  static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase);
>  
>  #ifdef CONFIG_OF
> +static void select_assert(void *context)
> +{
> +	struct eeprom_93xx46_dev *edev = context;
> +
> +	gpiod_set_value_cansleep(gpio_to_desc(edev->pdata->select_gpio), 1);

I would suggest to use gpio_set_value()

> +}
> +
> +static void select_deassert(void *context)
> +{
> +	struct eeprom_93xx46_dev *edev = context;
> +
> +	gpiod_set_value_cansleep(gpio_to_desc(edev->pdata->select_gpio), 0);

Same here.

> +}
> +
>  static const struct of_device_id eeprom_93xx46_of_table[] = {
>  	{ .compatible = "eeprom-93xx46", },
>  	{ .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, },
> @@ -385,6 +402,15 @@ static int eeprom_93xx46_probe_dt(struct spi_device *spi)
>  	if (of_property_read_bool(np, "read-only"))
>  		pd->flags |= EE_READONLY;
>  
> +	ret = of_get_named_gpio(np, "select-gpios", 0);

gpios or gpio? I see only one requested gpio.

> +	if (ret < 0) {
> +		pd->select_gpio = -1;
> +	} else {
> +		pd->select_gpio = ret;
> +		pd->prepare = select_assert;
> +		pd->finish = select_deassert;
> +	}
> +
>  	if (of_id->data) {
>  		const struct eeprom_93xx46_devtype_data *data = of_id->data;
>  
> diff --git a/include/linux/eeprom_93xx46.h b/include/linux/eeprom_93xx46.h
> index 92fa4c3..aa472c7 100644
> --- a/include/linux/eeprom_93xx46.h
> +++ b/include/linux/eeprom_93xx46.h
> @@ -21,4 +21,5 @@ struct eeprom_93xx46_platform_data {
>  	 */
>  	void (*prepare)(void *);
>  	void (*finish)(void *);
> +	unsigned int select_gpio;

Same questions as in v2 4/5.

>  };
> 

--
With best wishes,
Vladimir