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Date:   Tue, 10 Oct 2023 06:12:08 +0000
From:   Sakari Ailus <sakari.ailus@iki.fi>
To:     Kieran Bingham <kieran.bingham@ideasonboard.com>
Cc:     linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        "Paul J. Murphy" <paul.j.murphy@intel.com>,
        Daniele Alessandrelli <daniele.alessandrelli@intel.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/5] media: i2c: imx335: Enable regulator supplies
Message-ID: <ZSTrOB10pDhJq6gG@valkosipuli.retiisi.eu>
References: <20231010005126.3425444-1-kieran.bingham@ideasonboard.com>
 <20231010005126.3425444-3-kieran.bingham@ideasonboard.com>
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In-Reply-To: <20231010005126.3425444-3-kieran.bingham@ideasonboard.com>
Precedence: bulk

Hi Kieran,

On Tue, Oct 10, 2023 at 01:51:23AM +0100, Kieran Bingham wrote:
> Provide support for enabling and disabling regulator supplies to control
> power to the camera sensor.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> ---
>  drivers/media/i2c/imx335.c | 41 ++++++++++++++++++++++++++++++++++++--
>  1 file changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/imx335.c b/drivers/media/i2c/imx335.c
> index ec729126274b..bf12b9b69fce 100644
> --- a/drivers/media/i2c/imx335.c
> +++ b/drivers/media/i2c/imx335.c
> @@ -75,6 +75,19 @@ struct imx335_reg_list {
>  	const struct imx335_reg *regs;
>  };
>  
> +static const char * const imx335_supply_name[] = {
> +	/*
> +	 * Turn on the power supplies so that they rise in order of
> +	 *           1.2v,-> 1.8 -> 2.9v

This won't happen with regulator_bulk_enable(). Does the spec require this?

> +	 * All power supplies should finish rising within 200ms.
> +	 */
> +	"avdd", /* Analog (2.9V) supply */
> +	"ovdd", /* Digital I/O (1.8V) supply */
> +	"dvdd", /* Digital Core (1.2V) supply */
> +};
> +
> +#define IMX335_NUM_SUPPLIES ARRAY_SIZE(imx335_supply_name)
> +
>  /**
>   * struct imx335_mode - imx335 sensor mode structure
>   * @width: Frame width
> @@ -126,6 +139,8 @@ struct imx335 {
>  	struct v4l2_subdev sd;
>  	struct media_pad pad;
>  	struct gpio_desc *reset_gpio;
> +	struct regulator_bulk_data supplies[IMX335_NUM_SUPPLIES];
> +
>  	struct clk *inclk;
>  	struct v4l2_ctrl_handler ctrl_handler;
>  	struct v4l2_ctrl *link_freq_ctrl;
> @@ -781,6 +796,17 @@ static int imx335_parse_hw_config(struct imx335 *imx335)
>  		return PTR_ERR(imx335->reset_gpio);
>  	}
>  
> +	for (i = 0; i < IMX335_NUM_SUPPLIES; i++)
> +		imx335->supplies[i].supply = imx335_supply_name[i];
> +
> +	ret = devm_regulator_bulk_get(imx335->dev,
> +				      IMX335_NUM_SUPPLIES,
> +				      imx335->supplies);
> +	if (ret) {
> +		dev_err(imx335->dev, "Failed to get regulators\n");
> +		return ret;
> +	}
> +
>  	/* Get sensor input clock */
>  	imx335->inclk = devm_clk_get(imx335->dev, NULL);
>  	if (IS_ERR(imx335->inclk)) {
> @@ -859,6 +885,17 @@ static int imx335_power_on(struct device *dev)
>  	struct imx335 *imx335 = to_imx335(sd);
>  	int ret;
>  
> +	ret = regulator_bulk_enable(IMX335_NUM_SUPPLIES,
> +				    imx335->supplies);
> +	if (ret) {
> +		dev_err(dev, "%s: failed to enable regulators\n",
> +			__func__);
> +		return ret;
> +	}
> +
> +	usleep_range(500, 550); /* Tlow */

You're not handling the error case later on in the function.

> +
> +	/* Set XCLR */
>  	gpiod_set_value_cansleep(imx335->reset_gpio, 1);
>  
>  	ret = clk_prepare_enable(imx335->inclk);
> @@ -867,7 +904,7 @@ static int imx335_power_on(struct device *dev)
>  		goto error_reset;
>  	}
>  
> -	usleep_range(20, 22);
> +	usleep_range(20, 22); /* T4 */
>  
>  	return 0;
>  
> @@ -889,8 +926,8 @@ static int imx335_power_off(struct device *dev)
>  	struct imx335 *imx335 = to_imx335(sd);
>  
>  	gpiod_set_value_cansleep(imx335->reset_gpio, 0);
> -
>  	clk_disable_unprepare(imx335->inclk);
> +	regulator_bulk_disable(IMX335_NUM_SUPPLIES, imx335->supplies);
>  
>  	return 0;
>  }

-- 
Regards,

Sakari Ailus