From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Wu Subject: Re: [PATCH 3/5] media: ov2640: add primary dt support Date: Tue, 9 Dec 2014 11:10:01 +0800 Message-ID: <54866809.7020402@atmel.com> References: <1418038147-13221-1-git-send-email-josh.wu@atmel.com> <1418038147-13221-4-git-send-email-josh.wu@atmel.com> <13013762.Jqm1jQRnFM@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <13013762.Jqm1jQRnFM@avalon> Sender: linux-media-owner@vger.kernel.org To: Laurent Pinchart Cc: linux-media@vger.kernel.org, m.chehab@samsung.com, linux-arm-kernel@lists.infradead.org, g.liakhovetski@gmx.de, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi, Laurent On 12/9/2014 2:39 AM, Laurent Pinchart wrote: > Hi Josh, > > Thank you for the patch. > > On Monday 08 December 2014 19:29:05 Josh Wu wrote: >> Add device tree support for ov2640. >> >> Cc: devicetree@vger.kernel.org >> Signed-off-by: Josh Wu >> --- >> v1 -> v2: >> 1. use gpiod APIs. >> 2. change the gpio pin's name according to datasheet. >> 3. reduce the delay for .reset() function. >> >> drivers/media/i2c/soc_camera/ov2640.c | 86 +++++++++++++++++++++++++++++--- >> 1 file changed, 80 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/media/i2c/soc_camera/ov2640.c >> b/drivers/media/i2c/soc_camera/ov2640.c index 9ee910d..2a57979 100644 >> --- a/drivers/media/i2c/soc_camera/ov2640.c >> +++ b/drivers/media/i2c/soc_camera/ov2640.c >> @@ -18,6 +18,8 @@ >> #include >> #include >> #include >> +#include >> +#include >> #include >> #include >> >> @@ -283,6 +285,10 @@ struct ov2640_priv { >> u32 cfmt_code; >> struct v4l2_clk *clk; >> const struct ov2640_win_size *win; >> + >> + struct soc_camera_subdev_desc ssdd_dt; >> + struct gpio_desc *resetb_gpio; >> + struct gpio_desc *pwdn_gpio; >> }; >> >> /* >> @@ -1047,6 +1053,61 @@ static struct v4l2_subdev_ops ov2640_subdev_ops = { >> .video = &ov2640_subdev_video_ops, >> }; >> >> +/* OF probe functions */ >> +static int ov2640_hw_power(struct device *dev, int on) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct ov2640_priv *priv = to_ov2640(client); >> + >> + dev_dbg(&client->dev, "%s: %s the camera\n", >> + __func__, on ? "ENABLE" : "DISABLE"); >> + >> + if (priv->pwdn_gpio && !IS_ERR(priv->pwdn_gpio)) > No need to test for IS_ERR, as the probe function would have failed in that > case. right. I'll change it. > >> + gpiod_direction_output(priv->pwdn_gpio, !on); >> + >> + return 0; >> +} >> + >> +static int ov2640_hw_reset(struct device *dev) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct ov2640_priv *priv = to_ov2640(client); >> + >> + /* If enabled, give a reset impulse */ >> + if (priv->resetb_gpio && !IS_ERR(priv->resetb_gpio)) { > Same here. ditto. > >> + gpiod_direction_output(priv->resetb_gpio, 0); > Given that your DT should specify the active low GPIO flag, and that the gpiod > API inverts the value in that case, you should set the value to 1 here. Thanks for the information. I'll fix it. > >> + usleep_range(3000, 5000); >> + gpiod_direction_output(priv->resetb_gpio, 1); > And to 0 here. yes. > >> + } >> + >> + return 0; >> +} >> + >> +static int ov2640_probe_dt(struct i2c_client *client, >> + struct ov2640_priv *priv) >> +{ >> + priv->resetb_gpio = devm_gpiod_get_optional(&client->dev, "resetb", >> + GPIOD_OUT_HIGH); >> + if (!priv->resetb_gpio) >> + dev_warn(&client->dev, "resetb gpio not found!\n"); > No need to warn here, it's perfectly fine if the reset signal isn't connected > to a GPIO. I want to print some information if no GPIO is assigned. So I'd like use dev_dbg() here. What do you feel? > >> + else if (IS_ERR(priv->resetb_gpio)) >> + return -EINVAL; >> + >> + priv->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "pwdn", >> + GPIOD_OUT_HIGH); >> + if (!priv->pwdn_gpio) >> + dev_warn(&client->dev, "pwdn gpio not found!\n"); > Same here. ditto. > >> + else if (IS_ERR(priv->pwdn_gpio)) >> + return -EINVAL; >> + >> + /* Initialize the soc_camera_subdev_desc */ >> + priv->ssdd_dt.power = ov2640_hw_power; >> + priv->ssdd_dt.reset = ov2640_hw_reset; >> + client->dev.platform_data = &priv->ssdd_dt; >> + >> + return 0; >> +} >> + >> /* >> * i2c_driver functions >> */ >> @@ -1058,12 +1119,6 @@ static int ov2640_probe(struct i2c_client *client, >> struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); >> int ret; >> >> - if (!ssdd) { >> - dev_err(&adapter->dev, >> - "OV2640: Missing platform_data for driver\n"); >> - return -EINVAL; >> - } >> - >> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) { >> dev_err(&adapter->dev, >> "OV2640: I2C-Adapter doesn't support SMBUS\n"); >> @@ -1077,6 +1132,18 @@ static int ov2640_probe(struct i2c_client *client, >> return -ENOMEM; >> } >> >> + if (!ssdd) { >> + if (client->dev.of_node) { >> + ret = ov2640_probe_dt(client, priv); >> + if (ret) >> + return ret; >> + } else { >> + dev_err(&client->dev, >> + "Missing platform_data for driver\n"); >> + return -EINVAL; >> + } > I would test for !client->dev.of_node and return the error, you could then get > rid of the else and lower the indentation level for the call to > ov2640_probe_dt(). Okay. I'll change it in next version. Best Regards, Josh Wu > >> + } >> + >> v4l2_i2c_subdev_init(&priv->subdev, client, &ov2640_subdev_ops); >> v4l2_ctrl_handler_init(&priv->hdl, 2); >> v4l2_ctrl_new_std(&priv->hdl, &ov2640_ctrl_ops, >> @@ -1123,9 +1190,16 @@ static const struct i2c_device_id ov2640_id[] = { >> }; >> MODULE_DEVICE_TABLE(i2c, ov2640_id); >> >> +static const struct of_device_id ov2640_of_match[] = { >> + {.compatible = "ovti,ov2640", }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, ov2640_of_match); >> + >> static struct i2c_driver ov2640_i2c_driver = { >> .driver = { >> .name = "ov2640", >> + .of_match_table = of_match_ptr(ov2640_of_match), >> }, >> .probe = ov2640_probe, >> .remove = ov2640_remove,