Hi Sowjanya,
your patch looks good, but I have a few comments about the coding style,
see below.
On 15/07/20 06:24, Sowjanya Komatineni wrote:
> IMX274 has VANA analog 2.8V supply, VDIG digital core 1.8V supply,
> and VDDL digital io 1.2V supply which are optional based on camera
> module design.
>
> IMX274 also need external 24Mhz clock and is optional based on
> camera module design.
>
> This patch adds support for IMX274 power on and off to enable and
> disable these supplies and external clock.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/media/i2c/imx274.c | 170 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 167 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
> index 55869ff..8a34c07 100644
> --- a/drivers/media/i2c/imx274.c
> +++ b/drivers/media/i2c/imx274.c
> @@ -19,6 +19,7 @@
> #include <linux/module.h>
> #include <linux/of_gpio.h>
> #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/slab.h>
> #include <linux/v4l2-mediabus.h>
> #include <linux/videodev2.h>
> @@ -27,6 +28,8 @@
> #include <media/v4l2-device.h>
> #include <media/v4l2-subdev.h>
>
> +#define IMX274_DEFAULT_CLK_FREQ 24000000
> +
> /*
> * See "SHR, SVR Setting" in datasheet
> */
> @@ -501,6 +504,10 @@ struct imx274_ctrls {
> * @frame_rate: V4L2 frame rate structure
> * @regmap: Pointer to regmap structure
> * @reset_gpio: Pointer to reset gpio
> + * @vana_supply: VANA analog supply regulator
> + * @vdig_supply: VDIG digital core supply regulator
> + * @vddl_supply: VDDL digital io supply regulator
> + * @xclk: system clock to imx274
> * @lock: Mutex structure
> * @mode: Parameters for the selected readout mode
> */
> @@ -514,6 +521,10 @@ struct stimx274 {
> struct v4l2_fract frame_interval;
> struct regmap *regmap;
> struct gpio_desc *reset_gpio;
> + struct regulator *vana_supply;
> + struct regulator *vdig_supply;
> + struct regulator *vddl_supply;
> + struct clk *xclk;
> struct mutex lock; /* mutex lock for operations */
> const struct imx274_mode *mode;
> };
> @@ -767,6 +778,138 @@ static void imx274_reset(struct stimx274 *priv, int rst)
> usleep_range(IMX274_RESET_DELAY1, IMX274_RESET_DELAY2);
> }
>
> +/*
> + * imx274_power_on - Function called to power on the sensor
> + * @imx274: Pointer to device structure
> + */
> +static int imx274_power_on(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct stimx274 *imx274 = to_imx274(sd);
> + int ret;
> +
> + ret = clk_prepare_enable(imx274->xclk);
> + if (ret) {
> + dev_err(&imx274->client->dev, "Failed to enable clock\n");
> + return ret;
> + }
> +
> + if (imx274->vana_supply) {
> + ret = regulator_enable(imx274->vana_supply);
> + if (ret < 0) {
> + dev_err(&imx274->client->dev,
> + "Failed to enable VANA supply: %d\n", ret);
> + goto disable_clk;
> + }
> + }
> +
> + if (imx274->vdig_supply) {
> + ret = regulator_enable(imx274->vdig_supply);
> + if (ret < 0) {
> + dev_err(&imx274->client->dev,
> + "Failed to enable VDIG supply: %d\n", ret);
> + goto disable_vana_reg;
> + }
> + }
> +
> + if (imx274->vddl_supply) {
> + ret = regulator_enable(imx274->vddl_supply);
> + if (ret < 0) {
> + dev_err(&imx274->client->dev,
> + "Failed to enable VDDL supply: %d\n", ret);
> + goto disable_vdig_reg;
> + }
> + }
> +
> + usleep_range(1, 2);
> + imx274_reset(imx274, 1);
> +
> + return 0;
> +
> +disable_vdig_reg:
> + if (imx274->vdig_supply)
> + regulator_disable(imx274->vdig_supply);
> +disable_vana_reg:
> + if (imx274->vana_supply)
> + regulator_disable(imx274->vana_supply);
> +disable_clk:
> + clk_disable_unprepare(imx274->xclk);
> + return ret;
> +}
> +
> +/*
> + * imx274_power_off - Function called to power off the sensor
> + * @imx274: Pointer to device structure
> + */
> +static int imx274_power_off(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct stimx274 *imx274 = to_imx274(sd);
> +
> + imx274_reset(imx274, 0);
> +
> + if (imx274->vddl_supply)
> + regulator_disable(imx274->vddl_supply);
> +
> + if (imx274->vdig_supply)
> + regulator_disable(imx274->vdig_supply);
> +
> + if (imx274->vana_supply)
> + regulator_disable(imx274->vana_supply);
> +
> + clk_disable_unprepare(imx274->xclk);
> +
> + return 0;
> +}
> +
> +static int imx274_get_regulators(struct device *dev, struct stimx274 *imx274)
> +{
To make code much more readable:
int err;
> + int i;
> +
> + imx274->vana_supply = devm_regulator_get_optional(dev, "VANA");
> + if (IS_ERR(imx274->vana_supply)) {
err = PTR_ERR(imx274->vana_supply)
and then use 'err' everywhere in place of PTR_ERR(imx274->vana_supply).
> + if (PTR_ERR(imx274->vana_supply) != -ENODEV) {
> + if (PTR_ERR(imx274->vana_supply) != -EPROBE_DEFER)
> + dev_err(&imx274->client->dev,
> + "Failed to get VANA supply: %ld\n",
> + PTR_ERR(imx274->vana_supply));
> + return PTR_ERR(imx274->vana_supply);
> + }
> +
> + imx274->vana_supply = NULL;
> + }
> +
> + imx274->vdig_supply = devm_regulator_get_optional(dev, "VDIG");
> + if (IS_ERR(imx274->vdig_supply)) {
> + if (PTR_ERR(imx274->vdig_supply) != -ENODEV) {
> + if (PTR_ERR(imx274->vdig_supply) != -EPROBE_DEFER)
> + dev_err(&imx274->client->dev,
> + "Failed to get VDIG supply: %ld\n",
> + PTR_ERR(imx274->vdig_supply));
> + return PTR_ERR(imx274->vdig_supply);
> + }
> +
> + imx274->vdig_supply = NULL;
> + }
> +
> + imx274->vddl_supply = devm_regulator_get_optional(dev, "VDDL");
> + if (IS_ERR(imx274->vddl_supply)) {
> + if (PTR_ERR(imx274->vddl_supply) != -ENODEV) {
> + if (PTR_ERR(imx274->vddl_supply) != -EPROBE_DEFER)
> + dev_err(&imx274->client->dev,
> + "Failed to get VDIG supply: %ld\n",
> + PTR_ERR(imx274->vddl_supply));
> + return PTR_ERR(imx274->vddl_supply);
> + }
> +
> + imx274->vddl_supply = NULL;
> + }
Here, as well as in imx274_power_on(), you have 3 identical sections for
the 3 regulators. Why not having an array of 3 elements in struct
stimx274 and then access them in a loop? You'll need also the names:
static const char* regulator_name[3] = { "VANA", "VDIG", "VDDL" };
> /**
> * imx274_s_ctrl - This is used to set the imx274 V4L2 controls
> * @ctrl: V4L2 control to be set
> @@ -1836,6 +1979,19 @@ static int imx274_probe(struct i2c_client *client)
>
> mutex_init(&imx274->lock);
>
> + imx274->xclk = devm_clk_get_optional(&client->dev, "xclk");
> + ret = clk_set_rate(imx274->xclk, IMX274_DEFAULT_CLK_FREQ);
Nitpicking, but I'd move this line closer to the end of the function in
order to set the clock rate only if all the get operations succeeded.
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to set xclk rate\n");
> + return ret;
> + }
> +
> + ret = imx274_get_regulators(&client->dev, imx274);
> + if (ret) {
> + dev_err(&client->dev, "Failed to get power regulators, err: %d\n", ret);
> + return ret;
> + }
> +
> /* initialize format */
> imx274->mode = &imx274_modes[IMX274_DEFAULT_BINNING];
> imx274->crop.width = IMX274_MAX_WIDTH;
> @@ -1883,15 +2039,20 @@ static int imx274_probe(struct i2c_client *client)
> goto err_me;
> }
>
> - /* pull sensor out of reset */
> - imx274_reset(imx274, 1);
> + /* power on the sensor */
> + ret = imx274_power_on(&client->dev);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "%s : imx274 power on failed\n", __func__);
> + goto err_me;
> + }
>
> /* initialize controls */
> ret = v4l2_ctrl_handler_init(&imx274->ctrls.handler, 4);
> if (ret < 0) {
> dev_err(&client->dev,
> "%s : ctrl handler init Failed\n", __func__);
> - goto err_me;
> + goto err_power_off;
> }
>
> imx274->ctrls.handler.lock = &imx274->lock;
> @@ -1958,6 +2119,8 @@ static int imx274_probe(struct i2c_client *client)
>
> err_ctrls:
> v4l2_ctrl_handler_free(&imx274->ctrls.handler);
> +err_power_off:
> + imx274_power_off(&client->dev);
> err_me:
> media_entity_cleanup(&sd->entity);
> err_regmap:
> @@ -1975,6 +2138,7 @@ static int imx274_remove(struct i2c_client *client)
>
> v4l2_async_unregister_subdev(sd);
> v4l2_ctrl_handler_free(&imx274->ctrls.handler);
> + imx274_power_off(&client->dev);
> media_entity_cleanup(&sd->entity);
> mutex_destroy(&imx274->lock);
> return 0;
>
--
Luca
