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author | Cory Tusar <cory.tusar@pid1solutions.com> | 2016-02-10 14:32:08 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-11 19:23:28 -0800 |
commit | 3ca9b1ac28398c6fe0bed335d2d71a35e1c5f7c9 (patch) | |
tree | 7c4bc01765b20b0f281648ff7833a7cbd8b94516 /drivers/misc/eeprom | |
parent | e1379b56e9e88653fcb58cbaa71cd6b1cc304918 (diff) | |
download | linux-3ca9b1ac28398c6fe0bed335d2d71a35e1c5f7c9.tar.gz linux-3ca9b1ac28398c6fe0bed335d2d71a35e1c5f7c9.tar.bz2 linux-3ca9b1ac28398c6fe0bed335d2d71a35e1c5f7c9.zip |
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: Cory Tusar <cory.tusar@pid1solutions.com>
Tested-by: Chris Healy <chris.healy@zii.aero>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/eeprom')
-rw-r--r-- | drivers/misc/eeprom/eeprom_93xx46.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c index a3c3136abf3e..f62ab29e293c 100644 --- a/drivers/misc/eeprom/eeprom_93xx46.c +++ b/drivers/misc/eeprom/eeprom_93xx46.c @@ -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; |