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[23.128.96.18]) by mx.google.com with ESMTP id l28si13876385pgu.550.2021.04.18.08.01.34; Sun, 18 Apr 2021 08:01:47 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230038AbhDRPB3 (ORCPT + 99 others); Sun, 18 Apr 2021 11:01:29 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:57593 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229691AbhDRPB1 (ORCPT ); Sun, 18 Apr 2021 11:01:27 -0400 X-Originating-IP: 5.92.65.68 Received: from uno.localdomain (mob-5-92-65-68.net.vodafone.it [5.92.65.68]) (Authenticated sender: jacopo@jmondi.org) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 867391BF206; Sun, 18 Apr 2021 15:00:53 +0000 (UTC) Date: Sun, 18 Apr 2021 17:01:33 +0200 From: Jacopo Mondi To: Laurent Pinchart Cc: Jacopo Mondi , Geert Uytterhoeven , Magnus Damm , Kieran Bingham , Rob Herring , linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/7] media: i2c: max9286: Use "maxim,gpio-poc" property Message-ID: <20210418150133.cql5qnnqj4p4fu6c@uno.localdomain> References: <20210415122602.87697-1-jacopo+renesas@jmondi.org> <20210415122602.87697-4-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Laurent, On Thu, Apr 15, 2021 at 10:19:30PM +0300, Laurent Pinchart wrote: > Hi Jacopo, > > Thank you for the patch. > > On Thu, Apr 15, 2021 at 02:25:58PM +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 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. > > > > Signed-off-by: Jacopo Mondi > > --- > > drivers/media/i2c/max9286.c | 119 ++++++++++++++++++++++++++++-------- > > 1 file changed, 93 insertions(+), 26 deletions(-) > > > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c > > index 6fd4d59fcc72..a8b37783d2ef 100644 > > --- a/drivers/media/i2c/max9286.c > > +++ b/drivers/media/i2c/max9286.c > > @@ -15,6 +15,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -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; > > > > @@ -1022,8 +1026,19 @@ 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) > > +{ > > + int ret = max9286_read(priv, 0x0f); > > + if (ret < 0) > > + return ret; > > + > > + ret = value ? (ret & 0x3) | BIT(offset) : (ret & 0x3) & ~BIT(offset); > > + return max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | ret); > > +} > > Was there anything wrong with v3, sharing the implementation between the Yes, my understanding that your comment about not mixing the two cases as they're mutually exclusive :) I found that it actually made sense, as my reasoning was to support both at the same time, but it was actually not possible. I then thought it was a good idea to keep them separate.... > gpio-controller and non gpio-controller cases ? In particular, caching > the state locally seems better, max9286_read() goes over I2C and is thus > slow. At the expense of an additional i2c read... The gpio is only toggled at power-up/down, so I considered this acceptable... Both solutions are ok with me, I can restore the usage of gpio->state or keep what I have here... The only argument in favour of using gpio->state is that it paves the way for the usage of 'gpio-poc' and for registering a gpio-controller on the other gpio line at the same time, in future.. I think I'll switch back to that solution then... Thanks j > > > + > > +static void max9286_gpiochip_set(struct gpio_chip *chip, > > + unsigned int offset, int value) > > { > > struct max9286_priv *priv = gpiochip_get_data(chip); > > > > @@ -1035,7 +1050,7 @@ static void max9286_gpio_set(struct gpio_chip *chip, > > max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state); > > } > > > > -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 +1070,8 @@ 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 +1084,71 @@ 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 > 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) > > + 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; > > +} > > + > > 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