[PATCHv4 05/15] ov7670: add devicetree support

[Hans Verkuil]

From: Hans Verkuil <hans.verk...@cisco.com>

Add DT support. Use it to get the reset and pwdn pins (if there are any).
Tested with one sensor requiring reset/pwdn and one sensor that doesn't
have reset/pwdn pins.

Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
---
 drivers/media/i2c/ov7670.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 912ff09c6100..7270c68ed18a 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -17,6 +17,8 @@
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/videodev2.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-mediabus.h>
@@ -229,6 +231,8 @@ struct ov7670_info {
        };
        struct ov7670_format_struct *fmt;  /* Current format */
        struct clk *clk;
+       struct gpio_desc *resetb_gpio;
+       struct gpio_desc *pwdn_gpio;
        int min_width;                  /* Filter out smaller sizes */
        int min_height;                 /* Filter out smaller sizes */
        int clock_speed;                /* External clock speed (MHz) */
@@ -591,8 +595,6 @@ static int ov7670_init(struct v4l2_subdev *sd, u32 val)
        return ov7670_write_array(sd, ov7670_default_regs);
 }
 
-
-
 static int ov7670_detect(struct v4l2_subdev *sd)
 {
        unsigned char v;
@@ -1549,6 +1551,27 @@ static const struct ov7670_devtype ov7670_devdata[] = {
        },
 };
 
+static int ov7670_init_gpio(struct i2c_client *client, struct ov7670_info 
*info)
+{
+       info->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
+                       GPIOD_OUT_LOW);
+       if (IS_ERR(info->pwdn_gpio)) {
+               dev_info(&client->dev, "can't get %s GPIO\n", "powerdown");
+               return PTR_ERR(info->pwdn_gpio);
+       }
+
+       info->resetb_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+                       GPIOD_OUT_LOW);
+       if (IS_ERR(info->resetb_gpio)) {
+               dev_info(&client->dev, "can't get %s GPIO\n", "reset");
+               return PTR_ERR(info->resetb_gpio);
+       }
+
+       usleep_range(3000, 5000);
+
+       return 0;
+}
+
 static int ov7670_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -1594,6 +1617,10 @@ static int ov7670_probe(struct i2c_client *client,
                return -EPROBE_DEFER;
        clk_prepare_enable(info->clk);
 
+       ret = ov7670_init_gpio(client, info);
+       if (ret)
+               goto clk_disable;
+
        info->clock_speed = clk_get_rate(info->clk) / 1000000;
        if (info->clock_speed < 10 || info->clock_speed > 48) {
                ret = -EINVAL;
@@ -1693,9 +1720,18 @@ static const struct i2c_device_id ov7670_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ov7670_id);
 
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id ov7670_of_match[] = {
+       { .compatible = "ovti,ov7670", },
+       { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ov7670_of_match);
+#endif
+
 static struct i2c_driver ov7670_driver = {
        .driver = {
                .name   = "ov7670",
+               .of_match_table = of_match_ptr(ov7670_of_match),
        },
        .probe          = ov7670_probe,
        .remove         = ov7670_remove,
-- 
2.11.0