[PATCH v7 3/6] ad5820: Add support for enable pin

[Ricardo Ribalda Delgado]

This patch adds support for a programmable enable pin. It can be used in
situations where the ANA-vcc is not configurable (dummy-regulator), or
just to have a more fine control of the power saving.

The use of the enable pin is optional.

Signed-off-by: Ricardo Ribalda Delgado <riba...@kernel.org>
Acked-by: Pavel Machek <pa...@ucw.cz>
---
 drivers/media/i2c/Kconfig  |  2 +-
 drivers/media/i2c/ad5820.c | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 78dc64d7b0e7..30d460844dff 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -975,7 +975,7 @@ if MEDIA_CAMERA_SUPPORT
 
 config VIDEO_AD5820
        tristate "AD5820 lens voice coil support"
-       depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
+       depends on GPIOLIB && I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
        help
          This is a driver for the AD5820 camera lens voice coil.
          It is used for example in Nokia N900 (RX-51).
diff --git a/drivers/media/i2c/ad5820.c b/drivers/media/i2c/ad5820.c
index 7a49651f4d1f..76aab651f217 100644
--- a/drivers/media/i2c/ad5820.c
+++ b/drivers/media/i2c/ad5820.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
 
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
@@ -47,6 +48,8 @@ struct ad5820_device {
        u32 focus_ramp_time;
        u32 focus_ramp_mode;
 
+       struct gpio_desc *enable_gpio;
+
        struct mutex power_lock;
        int power_count;
 
@@ -114,6 +117,8 @@ static int ad5820_power_off(struct ad5820_device *coil, 
bool standby)
                ret = ad5820_update_hw(coil);
        }
 
+       gpiod_set_value_cansleep(coil->enable_gpio, 0);
+
        ret2 = regulator_disable(coil->vana);
        if (ret)
                return ret;
@@ -128,6 +133,8 @@ static int ad5820_power_on(struct ad5820_device *coil, bool 
restore)
        if (ret < 0)
                return ret;
 
+       gpiod_set_value_cansleep(coil->enable_gpio, 1);
+
        if (restore) {
                /* Restore the hardware settings. */
                coil->standby = false;
@@ -138,6 +145,7 @@ static int ad5820_power_on(struct ad5820_device *coil, bool 
restore)
        return 0;
 
 fail:
+       gpiod_set_value_cansleep(coil->enable_gpio, 0);
        coil->standby = true;
        regulator_disable(coil->vana);
 
@@ -304,6 +312,15 @@ static int ad5820_probe(struct i2c_client *client,
                return ret;
        }
 
+       coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
+                                                   GPIOD_OUT_LOW);
+       if (IS_ERR(coil->enable_gpio)) {
+               ret = PTR_ERR(coil->enable_gpio);
+               if (ret != -EPROBE_DEFER)
+                       dev_err(&client->dev, "could not get enable gpio\n");
+               return ret;
+       }
+
        mutex_init(&coil->power_lock);
 
        v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
-- 
2.23.0