Hi Jacopo,
Thank you for the patch.
On Wed, Apr 14, 2021 at 03:51:25PM +0200, Jacopo Mondi wrote:
> The 'maxim,gpio-poc' property is used when the remote camera
> power-over-coax is controlled by one of the MAX9286 gpio lines,
> to instruct the driver about which line to use and what the line
> polarity is.
>
> Add to the max9286 driver support for parsing the newly introduce
s/introduce/introduced/
> property and use it if available in place of the usual supply, as it is
> not possible to establish one as consumer of the max9286 gpio
> controller.
>
> If the new property is present, no gpio controller is registered and
> 'poc-supply' is ignored.
>
> In order to maximize code re-use, break out the max9286 gpio handling
> function so that they can be used by the gpio controller through the
> gpio-consumer API, or directly by the driver code.
>
> Wrap the power up and power down routines to their own function to
> be able to use either the gpio line directly or the supply. This will
> make it easier to control the remote camera power at run time.
I would have split the patch in two, with a first patch that refactors
the code, and a second one that extends it, but that's no big deal.
> Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
> ---
> drivers/media/i2c/max9286.c | 125 +++++++++++++++++++++++++++---------
> 1 file changed, 96 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index 6fd4d59fcc72..0c125f7b3d9b 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -15,6 +15,7 @@
> #include <linux/fwnode.h>
> #include <linux/gpio/consumer.h>
> #include <linux/gpio/driver.h>
> +#include <linux/gpio/machine.h>
> #include <linux/i2c.h>
> #include <linux/i2c-mux.h>
> #include <linux/module.h>
> @@ -165,6 +166,9 @@ struct max9286_priv {
>
> u32 reverse_channel_mv;
>
> + u32 gpio_poc;
> + u32 gpio_poc_flags;
> +
> struct v4l2_ctrl_handler ctrls;
> struct v4l2_ctrl *pixelrate;
>
> @@ -1022,20 +1026,27 @@ static int max9286_setup(struct max9286_priv *priv)
> return 0;
> }
>
> -static void max9286_gpio_set(struct gpio_chip *chip,
> - unsigned int offset, int value)
> +static int max9286_gpio_set(struct max9286_priv *priv, unsigned int offset,
> + int value)
> {
> - struct max9286_priv *priv = gpiochip_get_data(chip);
> -
> if (value)
> priv->gpio_state |= BIT(offset);
> else
> priv->gpio_state &= ~BIT(offset);
>
> - max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
> + return max9286_write(priv, 0x0f,
> + MAX9286_0X0F_RESERVED | priv->gpio_state);
> +}
> +
> +static void max9286_gpiochip_set(struct gpio_chip *chip,
> + unsigned int offset, int value)
> +{
> + struct max9286_priv *priv = gpiochip_get_data(chip);
> +
> + max9286_gpio_set(priv, offset, value);
> }
>
> -static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +static int max9286_gpiochip_get(struct gpio_chip *chip, unsigned int offset)
> {
> struct max9286_priv *priv = gpiochip_get_data(chip);
>
> @@ -1055,8 +1066,8 @@ static int max9286_register_gpio(struct max9286_priv
> *priv)
> gpio->of_node = dev->of_node;
> gpio->ngpio = 2;
> gpio->base = -1;
> - gpio->set = max9286_gpio_set;
> - gpio->get = max9286_gpio_get;
> + gpio->set = max9286_gpiochip_set;
> + gpio->get = max9286_gpiochip_get;
> gpio->can_sleep = true;
>
> /* GPIO values default to high */
> @@ -1069,6 +1080,75 @@ static int max9286_register_gpio(struct max9286_priv
> *priv)
> return ret;
> }
>
> +static int max9286_parse_gpios(struct max9286_priv *priv)
> +{
> + struct device *dev = &priv->client->dev;
> + u32 gpio_poc[2];
> + int ret;
> +
> + /*
> + * Parse the "gpio-poc" vendor property. If the camera power is
> + * controlled by one of the MAX9286 gpio lines, do not register
> + * the gpio controller and ignore 'poc-supply'.
> + */
> + ret = of_property_read_u32_array(dev->of_node,
> + "maxim,gpio-poc", gpio_poc, 2);
> + if (!ret) {
> + priv->gpio_poc = gpio_poc[0];
> + priv->gpio_poc_flags = gpio_poc[1];
> + if ((priv->gpio_poc != 0 && priv->gpio_poc != 1) ||
You could simply test priv->gpio_poc > 1.
> + (priv->gpio_poc_flags != GPIO_ACTIVE_HIGH &&
> + priv->gpio_poc_flags != GPIO_ACTIVE_LOW)) {
> + dev_err(dev, "Invalid 'gpio-poc': (%u %u)\n",
> + priv->gpio_poc, priv->gpio_poc_flags);
> + return -EINVAL;
> + }
> +
> + /* GPIO values default to high */
> + priv->gpio_state = BIT(0) | BIT(1);
Why is that ?
> + priv->regulator = NULL;
As priv is initialized to 0, you can skip this.
> +
> + return 0;
> + }
> +
> + ret = max9286_register_gpio(priv);
> + if (ret)
> + return ret;
> +
> + priv->regulator = devm_regulator_get(dev, "poc");
> + if (IS_ERR(priv->regulator)) {
> + if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> + dev_err(dev, "Unable to get PoC regulator (%ld)\n",
> + PTR_ERR(priv->regulator));
> + return PTR_ERR(priv->regulator);
> + }
> +
> + return 0;
> +}
> +
> +static int max9286_poc_enable(struct max9286_priv *priv, bool enable)
> +{
> + int ret;
> +
> + /* If "poc-gpio" is used, toggle the line and do not use regulator. */
> + if (!priv->regulator)
> + return max9286_gpio_set(priv, priv->gpio_poc,
> + enable ^ priv->gpio_poc_flags);
> +
> + /* Otherwise PoC is controlled using a regulator. */
> + if (enable) {
> + ret = regulator_enable(priv->regulator);
> + if (ret < 0) {
> + dev_err(&priv->client->dev, "Unable to turn PoC on\n");
As error message when max9286_gpio_set() fails (at least in the enable
case) would be good too. Bonus points if there's a single dev_err()
call.
> + return ret;
> + }
> +
> + return 0;
> + }
> +
> + return regulator_disable(priv->regulator);
> +}
> +
> static int max9286_init(struct device *dev)
> {
> struct max9286_priv *priv;
> @@ -1078,17 +1158,14 @@ static int max9286_init(struct device *dev)
> client = to_i2c_client(dev);
> priv = i2c_get_clientdata(client);
>
> - /* Enable the bus power. */
> - ret = regulator_enable(priv->regulator);
> - if (ret < 0) {
> - dev_err(&client->dev, "Unable to turn PoC on\n");
> + ret = max9286_poc_enable(priv, true);
> + if (ret)
> return ret;
> - }
>
> ret = max9286_setup(priv);
> if (ret) {
> dev_err(dev, "Unable to setup max9286\n");
> - goto err_regulator;
> + goto err_poc_disable;
> }
>
> /*
> @@ -1098,7 +1175,7 @@ static int max9286_init(struct device *dev)
> ret = max9286_v4l2_register(priv);
> if (ret) {
> dev_err(dev, "Failed to register with V4L2\n");
> - goto err_regulator;
> + goto err_poc_disable;
> }
>
> ret = max9286_i2c_mux_init(priv);
> @@ -1114,8 +1191,8 @@ static int max9286_init(struct device *dev)
>
> err_v4l2_register:
> max9286_v4l2_unregister(priv);
> -err_regulator:
> - regulator_disable(priv->regulator);
> +err_poc_disable:
> + max9286_poc_enable(priv, false);
>
> return ret;
> }
> @@ -1286,20 +1363,10 @@ static int max9286_probe(struct i2c_client *client)
> */
> max9286_configure_i2c(priv, false);
>
> - ret = max9286_register_gpio(priv);
> + ret = max9286_parse_gpios(priv);
> if (ret)
> goto err_powerdown;
>
> - priv->regulator = devm_regulator_get(&client->dev, "poc");
> - if (IS_ERR(priv->regulator)) {
> - if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
> - dev_err(&client->dev,
> - "Unable to get PoC regulator (%ld)\n",
> - PTR_ERR(priv->regulator));
> - ret = PTR_ERR(priv->regulator);
> - goto err_powerdown;
> - }
> -
> ret = max9286_parse_dt(priv);
> if (ret)
> goto err_powerdown;
> @@ -1326,7 +1393,7 @@ static int max9286_remove(struct i2c_client *client)
>
> max9286_v4l2_unregister(priv);
>
> - regulator_disable(priv->regulator);
> + max9286_poc_enable(priv, false);
>
> gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>
--
Regards,
Laurent Pinchart
