Re: [PATCH v2 2/3] media: ov5675: add device-tree support

From: Jacopo Mondi
Date: Thu May 05 2022 - 03:47:38 EST

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In reply to: Quentin Schulz: "[PATCH v2 2/3] media: ov5675: add device-tree support"
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Hi Quentin,

On Wed, May 04, 2022 at 03:55:42PM +0200, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
>
> Until now, this driver only supported ACPI. This adds support for
> Device Tree too.
>
> This is heavily inspired by device tree support addition to OV8856
> driver. The differentiation between ACPI and DT mode is done through an
> is_acpi_node check.
>
> Cc: Quentin Schulz <foss+kernel@xxxxxxxxx>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
> ---
>
> v2:
> - fixed unused-const-variable warning by removing of_match_ptr in
> of_match_table, reported by kernel test robot,
>
> drivers/media/i2c/ov5675.c | 134 +++++++++++++++++++++++++++++++++----
> 1 file changed, 121 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
> index 82ba9f56baec..ccbc8dc506ff 100644
> --- a/drivers/media/i2c/ov5675.c
> +++ b/drivers/media/i2c/ov5675.c
> @@ -3,10 +3,13 @@
>
> #include <asm/unaligned.h>
> #include <linux/acpi.h>
> +#include <linux/clk.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/i2c.h>

#include <linux/mod_devicetable.h>

for struct of_device_id

> #include <linux/module.h>
> #include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-fwnode.h>
> @@ -17,7 +20,7 @@
>
> #define OV5675_LINK_FREQ_450MHZ 450000000ULL
> #define OV5675_SCLK 90000000LL
> -#define OV5675_MCLK 19200000
> +#define OV5675_XVCLK_19_2 19200000
> #define OV5675_DATA_LANES 2
> #define OV5675_RGB_DEPTH 10
>
> @@ -76,6 +79,14 @@
>
> #define to_ov5675(_sd) container_of(_sd, struct ov5675, sd)
>
> +static const char * const ov5675_supply_names[] = {
> + "avdd", /* Analog power */
> + "dovdd", /* Digital I/O power */
> + "dvdd", /* Digital core power */
> +};
> +
> +#define OV5675_NUM_SUPPLIES ARRAY_SIZE(ov5675_supply_names)
> +
> enum {
> OV5675_LINK_FREQ_900MBPS,
> };
> @@ -484,6 +495,9 @@ struct ov5675 {
> struct v4l2_subdev sd;
> struct media_pad pad;
> struct v4l2_ctrl_handler ctrl_handler;
> + struct clk *xvclk;
> + struct gpio_desc *reset_gpio;
> + struct regulator_bulk_data supplies[OV5675_NUM_SUPPLIES];
>
> /* V4L2 Controls */
> struct v4l2_ctrl *link_freq;
> @@ -944,6 +958,52 @@ static int ov5675_set_stream(struct v4l2_subdev *sd, int enable)
> return ret;
> }
>
> +static void __ov5675_power_off(struct ov5675 *ov5675)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&ov5675->sd);
> +
> + if (is_acpi_node(dev_fwnode(&client->dev)))
> + return;
> +
> + gpiod_set_value_cansleep(ov5675->reset_gpio, 1);
> + usleep_range(1000, 1200);
> +
> + regulator_bulk_disable(OV5675_NUM_SUPPLIES, ov5675->supplies);
> + clk_disable_unprepare(ov5675->xvclk);
> +}
> +
> +static int __ov5675_power_on(struct ov5675 *ov5675)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&ov5675->sd);
> + int ret;
> +
> + if (is_acpi_node(dev_fwnode(&client->dev)))

A question for Sakari here:

I have a similar series for ov5670, where I don't use is_acpi_node()
https://patchwork.linuxtv.org/project/linux-media/patch/20220329090133.338073-7-jacopo@xxxxxxxxxx/

should this be done for all drivers supporting acpi && OF ?

> + return 0;
> +
> + ret = clk_prepare_enable(ov5675->xvclk);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed to enable xvclk: %d\n", ret);
> + return ret;
> + }
> +
> + gpiod_set_value_cansleep(ov5675->reset_gpio, 1);
> +
> + /* Reset pulse should be at least 2ms */
> + usleep_range(2000, 2200);
> +
> + ret = regulator_bulk_enable(OV5675_NUM_SUPPLIES, ov5675->supplies);
> + if (ret) {
> + clk_disable_unprepare(ov5675->xvclk);
> + return ret;
> + }
> +
> + gpiod_set_value_cansleep(ov5675->reset_gpio, 0);
> +
> + usleep_range(1000, 1200);
> +
> + return 0;
> +}
> +
> static int __maybe_unused ov5675_suspend(struct device *dev)
> {
> struct v4l2_subdev *sd = dev_get_drvdata(dev);
> @@ -953,6 +1013,7 @@ static int __maybe_unused ov5675_suspend(struct device *dev)
> if (ov5675->streaming)
> ov5675_stop_streaming(ov5675);
>
> + __ov5675_power_off(ov5675);

So you plumb the device power/up down in the SYSTEM_SLEEP_PM_OPS() callbacks ?

My understanding is that it would be better to create RUNTIME_PM_OPS()
for this, so that the device can be runtime suspended/resumed.

Be aware my understanding of runtime_pm is limited, better check with
Sakari too (I'll ask him to have a look).

> mutex_unlock(&ov5675->mutex);
>
> return 0;
> @@ -965,6 +1026,8 @@ static int __maybe_unused ov5675_resume(struct device *dev)
> int ret;
>
> mutex_lock(&ov5675->mutex);
> +
> + __ov5675_power_on(ov5675);
> if (ov5675->streaming) {
> ret = ov5675_start_streaming(ov5675);
> if (ret) {
> @@ -1106,32 +1169,60 @@ static const struct v4l2_subdev_internal_ops ov5675_internal_ops = {
> .open = ov5675_open,
> };
>
> -static int ov5675_check_hwcfg(struct device *dev)
> +static int ov5675_get_hwcfg(struct ov5675 *ov5675, struct device *dev)
> {
> struct fwnode_handle *ep;
> struct fwnode_handle *fwnode = dev_fwnode(dev);
> struct v4l2_fwnode_endpoint bus_cfg = {
> .bus_type = V4L2_MBUS_CSI2_DPHY
> };
> - u32 mclk;
> + u32 xvclk_rate;
> int ret;
> unsigned int i, j;
>
> if (!fwnode)
> return -ENXIO;
>
> - ret = fwnode_property_read_u32(fwnode, "clock-frequency", &mclk);
> + ret = fwnode_property_read_u32(fwnode, "clock-frequency", &xvclk_rate);

Isn't "clock-frequency" a leftover from ACPI ? It shouldn't be in the OF
bindings either (you have it in 1/3).

You can use the common clock framework API as you do below for OF and
parse "clock-frequency" only for ACPI, as far as I can tell.

> if (ret) {
> dev_err(dev, "can't get clock frequency");
> return ret;
> }
>
> - if (mclk != OV5675_MCLK) {
> - dev_err(dev, "external clock %d is not supported", mclk);
> + if (!is_acpi_node(fwnode)) {
> + ov5675->xvclk = devm_clk_get(dev, "xvclk");
> + if (IS_ERR(ov5675->xvclk)) {
> + ret = PTR_ERR(ov5675->xvclk);
> + dev_err(dev, "failed to get xvclk: %d\n", ret);
> + return ret;
> + }
> +
> + clk_set_rate(ov5675->xvclk, xvclk_rate);
> + xvclk_rate = clk_get_rate(ov5675->xvclk);

> + }
> +
> + if (xvclk_rate != OV5675_XVCLK_19_2) {
> + dev_err(dev, "external clock rate %u is unsupported", xvclk_rate);
> return -EINVAL;
> }
>
> + ov5675->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ov5675->reset_gpio)) {
> + ret = PTR_ERR(ov5675->reset_gpio);
> + dev_err(dev, "failed to get reset-gpios: %d\n", ret);
> + return ret;
> + }
> +
> + for (i = 0; i < OV5675_NUM_SUPPLIES; i++)
> + ov5675->supplies[i].supply = ov5675_supply_names[i];
> +
> + ret = devm_regulator_bulk_get(dev, OV5675_NUM_SUPPLIES,
> + ov5675->supplies);
> + if (ret)
> + return ret;
> +
> ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
> if (!ep)
> return -ENXIO;
> @@ -1186,6 +1277,8 @@ static int ov5675_remove(struct i2c_client *client)
> pm_runtime_disable(&client->dev);
> mutex_destroy(&ov5675->mutex);
>
> + __ov5675_power_off(ov5675);
> +
> return 0;
> }
>
> @@ -1195,25 +1288,31 @@ static int ov5675_probe(struct i2c_client *client)
> bool full_power;
> int ret;
>
> - ret = ov5675_check_hwcfg(&client->dev);
> + ov5675 = devm_kzalloc(&client->dev, sizeof(*ov5675), GFP_KERNEL);
> + if (!ov5675)
> + return -ENOMEM;
> +
> + ret = ov5675_get_hwcfg(ov5675, &client->dev);
> if (ret) {
> - dev_err(&client->dev, "failed to check HW configuration: %d",
> + dev_err(&client->dev, "failed to get HW configuration: %d",
> ret);
> return ret;
> }
>
> - ov5675 = devm_kzalloc(&client->dev, sizeof(*ov5675), GFP_KERNEL);
> - if (!ov5675)
> - return -ENOMEM;
> -
> v4l2_i2c_subdev_init(&ov5675->sd, client, &ov5675_subdev_ops);
>
> + ret = __ov5675_power_on(ov5675);
> + if (ret) {
> + dev_err(&client->dev, "failed to power on: %d\n", ret);
> + return ret;
> + }
> +
> full_power = acpi_dev_state_d0(&client->dev);
> if (full_power) {
> ret = ov5675_identify_module(ov5675);
> if (ret) {
> dev_err(&client->dev, "failed to find sensor: %d", ret);
> - return ret;
> + goto probe_power_off;
> }
> }

Maybe you can also update the comment at the end of the probe function
to remove references to ACPI. As you wish.

/*
* Device is already turned on by i2c-core with ACPI domain PM.
* Enable runtime PM and turn off the device.
*/

Thanks
j

>
> @@ -1262,6 +1361,8 @@ static int ov5675_probe(struct i2c_client *client)
> probe_error_v4l2_ctrl_handler_free:
> v4l2_ctrl_handler_free(ov5675->sd.ctrl_handler);
> mutex_destroy(&ov5675->mutex);
> +probe_power_off:
> + __ov5675_power_off(ov5675);
>
> return ret;
> }
> @@ -1279,11 +1380,18 @@ static const struct acpi_device_id ov5675_acpi_ids[] = {
> MODULE_DEVICE_TABLE(acpi, ov5675_acpi_ids);
> #endif
>
> +static const struct of_device_id ov5675_of_match[] = {
> + { .compatible = "ovti,ov5675", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, ov5675_of_match);
> +
> static struct i2c_driver ov5675_i2c_driver = {
> .driver = {
> .name = "ov5675",
> .pm = &ov5675_pm_ops,
> .acpi_match_table = ACPI_PTR(ov5675_acpi_ids),
> + .of_match_table = ov5675_of_match,
> },
> .probe_new = ov5675_probe,
> .remove = ov5675_remove,
> --
> 2.35.1
>

Next message: Sascha Hauer: "Re: [PATCH] ASoC: fsl_micfil: fix the naming style for mask definition"
Previous message: Shengjiu Wang: "[PATCH] ASoC: fsl_micfil: fix the naming style for mask definition"
In reply to: Quentin Schulz: "[PATCH v2 2/3] media: ov5675: add device-tree support"
Next in thread: Sakari Ailus: "Re: [PATCH v2 2/3] media: ov5675: add device-tree support"
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