Hi Kieran, On Thu, Jun 17, 2021 at 10:19:06AM +0200, Jacopo Mondi wrote: > Hi Kieran > > On Thu, Jun 17, 2021 at 01:02:36AM +0100, Kieran Bingham wrote: > > Hi Jacopo, > > > > On 19/04/2021 15:23, 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 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 think I've seen Laurent's despair at the auxillary device bus already, > > but I can't help but feel it might be a way to register the gpio and > > regulator fully without having to handle any probe deferrals and allow > > the GPIO chip to be used as it's own regulator. (I.e. solve the issues I > > was facing last time I looked at it) > > > > But that said however, it's only a hypothesis having not yet fully > > investigated the option. It seems a shame to have to expose multiple > > ways of powering up the cameras, but I guess ultimately it's how the > > hardware is connected. > > I can't really comment as I don't know what auxillary bus is, but I > guess this simple solution is enough to unblock eagle upstreaming and > doesn't tie our hands if we want to switch to something completely > different in future. > > > > > Have we confirmed that the start up delays are no longer needed for the > > RDACM20 cameras? (which we've previously exposed as a regulator power up > > delay?) > > Yes, not delay needed as long as > https://patchwork.linuxtv.org/project/linux-media/patch/20210616124616.49249-12-jacopo+renesas@xxxxxxxxxx/ > is applied > Let me (again) correct myself about the RDACM20. While the above mentioned patch solves all issues at boot time, it still doesn't guarantee stability of the capture operations. I blame write collision or rather the MCU changing our programming after the boot phase. I get an error when accessing the max9271 at s_stream() time, while during boot I can read its id consistently. I'm afraid we somehow need that delay to let the MCU boot complete and overwrite its settings, in this way I get a 100% success of the capture operations. > > > > How would this handle those delays if required? > > > > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > > > --- > > > drivers/media/i2c/max9286.c | 125 +++++++++++++++++++++++++++--------- > > > 1 file changed, 94 insertions(+), 31 deletions(-) > > > > > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c > > > index 6fd4d59fcc72..99160aa68a5f 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); > > > > > > @@ -1055,16 +1066,81 @@ 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; > > > > > > + ret = devm_gpiochip_add_data(dev, gpio, priv); > > > + if (ret) > > > + dev_err(dev, "Unable to create gpio_chip\n"); > > > + > > > + return ret; > > > +} > > > + > > > +static int max9286_parse_gpios(struct max9286_priv *priv) > > > +{ > > > + struct device *dev = &priv->client->dev; > > > + u32 gpio_poc[2]; > > > + int ret; > > > + > > > /* GPIO values default to high */ > > > priv->gpio_state = BIT(0) | BIT(1); > > > > > > - ret = devm_gpiochip_add_data(dev, gpio, priv); > > > + /* > > > + * 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 > 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; > > > + } > > > + > > > + return 0; > > > + } > > > + > > > + ret = max9286_register_gpio(priv); > > > if (ret) > > > - dev_err(dev, "Unable to create gpio_chip\n"); > > > + 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 (enable) > > > + ret = priv->regulator > > > + ? regulator_enable(priv->regulator) > > > + : max9286_gpio_set(priv, priv->gpio_poc, > > > + enable ^ priv->gpio_poc_flags); > > > + else > > > + ret = priv->regulator > > > + ? regulator_disable(priv->regulator) > > > + : max9286_gpio_set(priv, priv->gpio_poc, > > > + enable ^ priv->gpio_poc_flags); > > > + > > > + if (ret < 0) > > > + dev_err(&priv->client->dev, "Unable to turn PoC %s\n", > > > + enable ? "on" : "off"); > > > > > > return ret; > > > } > > > @@ -1078,17 +1154,14 @@ 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 +1171,7 @@ 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 +1187,8 @@ 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 +1359,10 @@ 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 +1389,7 @@ 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 > > -- > > Kieran
