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Commit 3ca9b1ac authored by Cory Tusar's avatar Cory Tusar Committed by Greg Kroah-Hartman
Browse files

misc: eeprom_93xx46: Add support for a GPIO 'select' line. 



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: default avatarCory Tusar <cory.tusar@pid1solutions.com>
Tested-by: default avatarChris Healy <chris.healy@zii.aero>
Reviewed-by: default avatarVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e1379b56

drivers/misc/eeprom/eeprom_93xx46.c

+35 −0
Original line number Diff line number Diff line
@@ -10,11 +10,13 @@ 


#include <linux/delay.h>

#include <linux/device.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>

#include <linux/slab.h>

#include <linux/spi/spi.h>

#include <linux/sysfs.h>
@@ -343,6 +345,20 @@ static ssize_t eeprom_93xx46_store_erase(struct device *dev, 
}

static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase);



static void select_assert(void *context)

{

	struct eeprom_93xx46_dev *edev = context;



	gpiod_set_value_cansleep(edev->pdata->select, 1);

}



static void select_deassert(void *context)

{

	struct eeprom_93xx46_dev *edev = context;



	gpiod_set_value_cansleep(edev->pdata->select, 0);

}



static const struct of_device_id eeprom_93xx46_of_table[] = {

	{ .compatible = "eeprom-93xx46", },

	{ .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, },
@@ -357,6 +373,8 @@ static int eeprom_93xx46_probe_dt(struct spi_device *spi) 
	struct device_node *np = spi->dev.of_node;

	struct eeprom_93xx46_platform_data *pd;

	u32 tmp;

	int gpio;

	enum of_gpio_flags of_flags;

	int ret;



	pd = devm_kzalloc(&spi->dev, sizeof(*pd), GFP_KERNEL);
@@ -381,6 +399,23 @@ static int eeprom_93xx46_probe_dt(struct spi_device *spi) 
	if (of_property_read_bool(np, "read-only"))

		pd->flags |= EE_READONLY;



	gpio = of_get_named_gpio_flags(np, "select-gpios", 0, &of_flags);

	if (gpio_is_valid(gpio)) {

		unsigned long flags =

			of_flags == OF_GPIO_ACTIVE_LOW ? GPIOF_ACTIVE_LOW : 0;



		ret = devm_gpio_request_one(&spi->dev, gpio, flags,

					    "eeprom_93xx46_select");

		if (ret)

			return ret;



		pd->select = gpio_to_desc(gpio);

		pd->prepare = select_assert;

		pd->finish = select_deassert;



		gpiod_direction_output(pd->select, 0);

	}



	if (of_id->data) {

		const struct eeprom_93xx46_devtype_data *data = of_id->data;

include/linux/eeprom_93xx46.h

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 
 * platform description for 93xx46 EEPROMs.

 */



struct gpio_desc;



struct eeprom_93xx46_platform_data {

	unsigned char	flags;

#define EE_ADDR8	0x01		/*  8 bit addr. cfg */
@@ -21,4 +23,5 @@ struct eeprom_93xx46_platform_data { 
	 */

	void (*prepare)(void *);

	void (*finish)(void *);

	struct gpio_desc *select;

};