From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Wu Subject: Re: [PATCH 2/4] media: ov2640: add primary dt support Date: Fri, 5 Dec 2014 18:17:44 +0800 Message-ID: <54818648.8030601@atmel.com> References: <1417170507-11172-1-git-send-email-josh.wu@atmel.com> <1417170507-11172-3-git-send-email-josh.wu@atmel.com> <2588866.n5Pjp1h670@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2588866.n5Pjp1h670@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 12/2/2014 6:33 AM, Laurent Pinchart wrote: > Hi Josh, > > Thank you for the patch. > > On Friday 28 November 2014 18:28:25 Josh Wu wrote: >> Add device tree support for ov2640. >> >> Cc:devicetree@vger.kernel.org >> Signed-off-by: Josh Wu >> --- >> drivers/media/i2c/soc_camera/ov2640.c | 95 +++++++++++++++++++++++++++++--- >> 1 file changed, 89 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/media/i2c/soc_camera/ov2640.c >> b/drivers/media/i2c/soc_camera/ov2640.c index 9ee910d..6506126 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; >> + int reset_pin; >> + int pwr_down_pin; >> }; >> >> /* >> @@ -1047,6 +1053,70 @@ 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"); >> + >> + /* enable or disable the camera */ >> + gpio_direction_output(priv->pwr_down_pin, !on); > Isn't there a delay required to wake the chip up ? I don't see any document mention a delay is needed when waked up. > >> + >> + 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 the reset GPIO isn't specified you should return immediately without > waiting 120ms. I find some document that said the reset pulse need >= 3ms. So I think use 3~5ms is enough. > >> + /* If enabled, give a reset impulse */ >> + gpio_direction_output(priv->reset_pin, 0); >> + msleep(20); > Please use usleep_range(). ok. > >> + gpio_direction_output(priv->reset_pin, 1); >> + msleep(100); > Is the reset delay documented somewhere ? 100ms seems pretty large to me. It seems no need to wait another delay after the reset pulse is generated. I will remove this line: msleep(100); >> + >> + return 0; >> +} >> + >> +static int ov2640_probe_dt(struct i2c_client *client, >> + struct ov2640_priv *priv) >> +{ >> + struct device_node *np = client->dev.of_node; >> + int ret; >> + >> + priv->reset_pin = of_get_named_gpio(np, "reset-gpio", 0); >> + priv->pwr_down_pin = of_get_named_gpio(np, "power-down-gpio", 0); >> + if (!gpio_is_valid(priv->reset_pin) || >> + !gpio_is_valid(priv->pwr_down_pin)) >> + return -EINVAL; >> + >> + ret = devm_gpio_request(&client->dev, priv->pwr_down_pin, >> + "power-down-pin"); >> + if (ret < 0) { >> + dev_err(&client->dev, "request gpio pin %d failed\n", >> + priv->pwr_down_pin); >> + return ret; >> + } >> + >> + ret = devm_gpio_request(&client->dev, priv->reset_pin, "reset_pin"); >> + if (ret < 0) { >> + dev_err(&client->dev, "request gpio pin %d failed\n", >> + priv->reset_pin); >> + return ret; >> + } > Please use the gpiod API with the devm_gpiod_get_index_optional() function, it > will simply your code and take care about GPIO polarity automatically. Don't > forget to specify the default state using the GPIOD_* flags. Thank, I will use it. It seems in this case, use devm_gpiod_get_optional() is enough. Best Regards, Josh Wu > >> + >> + /* 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 +1128,6 @@ 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 +1141,18 @@ 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; >> + } >> + } >> + >> 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 +1199,16 @@ static const struct i2c_device_id ov2640_id[] = { >> }; >> MODULE_DEVICE_TABLE(i2c, ov2640_id); >> >> +static const struct of_device_id ov2640_of_match[] = { >> + {.compatible = "omnivision,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,