Re: [PATCH v3 2/2] media: i2c: Add IMX296 CMOS image sensor driver

From: Manivannan Sadhasivam
Date: Wed Oct 30 2019 - 02:26:49 EST

Hi Sakari,

Thanks for the review!

On Tue, Oct 29, 2019 at 02:13:20PM +0200, Sakari Ailus wrote:
> Hi Manivannan,
>
> On Fri, Oct 25, 2019 at 11:29:08PM +0530, Manivannan Sadhasivam wrote:
> > Add driver for Sony IMX296 CMOS image sensor driver. The driver only
> > supports I2C interface for programming and MIPI CSI-2 for sensor output.
> >
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > MAINTAINERS | 8 +
> > drivers/media/i2c/Kconfig | 11 +
> > drivers/media/i2c/Makefile | 1 +
> > drivers/media/i2c/imx296.c | 733 +++++++++++++++++++++++++++++++++++++
> > 4 files changed, 753 insertions(+)
> > create mode 100644 drivers/media/i2c/imx296.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 55199ef7fa74..5b7332d121d8 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -15140,6 +15140,14 @@ S: Maintained
> > F: drivers/media/i2c/imx274.c
> > F: Documentation/devicetree/bindings/media/i2c/imx274.txt
> >
> > +SONY IMX296 SENSOR DRIVER
> > +M: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > +L: linux-media@xxxxxxxxxxxxxxx
> > +T: git git://linuxtv.org/media_tree.git
> > +S: Maintained
> > +F: drivers/media/i2c/imx296.c
> > +F: Documentation/devicetree/bindings/media/i2c/imx296.txt
>
> The new bindings are in YAML format, so txt -> yaml.
>
> Also the MAINTAINERS change needs to be done no later than adding the
> files.
>

Ah, yes!

> > +
> > SONY IMX319 SENSOR DRIVER
> > M: Bingbu Cao <bingbu.cao@xxxxxxxxx>
> > L: linux-media@xxxxxxxxxxxxxxx
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index 7eee1812bba3..930db46fa2b8 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -598,6 +598,17 @@ config VIDEO_IMX274
> > This is a V4L2 sensor driver for the Sony IMX274
> > CMOS image sensor.
> >
> > +config VIDEO_IMX296
> > + tristate "Sony IMX296 sensor support"
> > + depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> > + select V4L2_FWNODE
> > + help
> > + This is a Video4Linux2 sensor driver for the Sony
> > + IMX296 camera sensor.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called imx296.
> > +
> > config VIDEO_IMX319
> > tristate "Sony IMX319 sensor support"
> > depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
> > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > index beb170b002dc..ed0c02bda450 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -112,6 +112,7 @@ obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > obj-$(CONFIG_VIDEO_IMX214) += imx214.o
> > obj-$(CONFIG_VIDEO_IMX258) += imx258.o
> > obj-$(CONFIG_VIDEO_IMX274) += imx274.o
> > +obj-$(CONFIG_VIDEO_IMX296) += imx296.o
> > obj-$(CONFIG_VIDEO_IMX319) += imx319.o
> > obj-$(CONFIG_VIDEO_IMX355) += imx355.o
> > obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> > diff --git a/drivers/media/i2c/imx296.c b/drivers/media/i2c/imx296.c
> > new file mode 100644
> > index 000000000000..98fff0a93277
> > --- /dev/null
> > +++ b/drivers/media/i2c/imx296.c
> > @@ -0,0 +1,733 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Sony IMX296 CMOS Image Sensor Driver
> > + *
> > + * Copyright (C) 2019 FRAMOS GmbH.
> > + *
> > + * Copyright (C) 2019 Linaro Ltd.
> > + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <media/media-entity.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-device.h>
> > +#include <media/v4l2-fwnode.h>
> > +#include <media/v4l2-subdev.h>
> > +
> > +#define IMX296_STANDBY 0x3000
> > +#define IMX296_REGHOLD 0x3008
> > +#define IMX296_XMSTA 0x300a
> > +#define IMX296_GAIN_LOW 0x3204
> > +#define IMX296_GAIN_HIGH 0x3205
> > +
> > +#define IMX296_DEFAULT_FORMAT MEDIA_BUS_FMT_SRGGB10_1X10
> > +
> > +static const char * const imx296_supply_name[] = {
> > + "vdda",
> > + "vddd",
> > + "vddo",
> > +};
> > +
> > +#define IMX296_NUM_SUPPLIES ARRAY_SIZE(imx296_supply_name)
> > +
> > +struct imx296_regval {
> > + u16 reg;
> > + u8 val;
> > +};
> > +
> > +struct imx296_mode {
> > + u32 width;
> > + u32 height;
> > + u32 pixel_rate;
> > +
> > + const struct imx296_regval *data;
> > + u32 data_size;
> > +};
> > +
> > +struct imx296 {
> > + struct device *dev;
> > + struct clk *mclk;
> > + struct regmap *regmap;
> > +
> > + struct v4l2_subdev sd;
> > + struct v4l2_fwnode_endpoint ep;
> > + struct media_pad pad;
> > + struct v4l2_mbus_framefmt current_format;
> > + const struct imx296_mode *current_mode;
> > +
> > + struct regulator_bulk_data supplies[IMX296_NUM_SUPPLIES];
> > + struct gpio_desc *rst_gpio;
> > +
> > + struct v4l2_ctrl_handler ctrls;
> > + struct v4l2_ctrl *pixel_rate;
> > +
> > + struct mutex lock;
> > +};
> > +
> > +static const struct regmap_config imx296_regmap_config = {
> > + .reg_bits = 16,
> > + .val_bits = 8,
> > + .cache_type = REGCACHE_RBTREE,
> > +};
> > +
> > +static const struct imx296_regval imx296_global_init_settings[] = {
> > + { 0x3a00, 0x80 },
> > + { 0x3005, 0xf0 },
> > + { 0x350b, 0x0f },
> > + { 0x300d, 0x00 },
> > + { 0x400e, 0x58 },
> > + { 0x3010, 0x5e },
> > + { 0x3011, 0x04 },
> > + { 0x3014, 0x4c },
> > + { 0x4014, 0x1c },
> > + { 0x3015, 0x04 },
> > + { 0x3516, 0x77 },
> > + { 0x321a, 0x00 },
> > + { 0x3226, 0x02 },
> > + { 0x3832, 0xf5 },
> > + { 0x3833, 0x00 },
> > + { 0x3541, 0x72 },
> > + { 0x4041, 0x2a },
> > + { 0x3d48, 0xa3 },
> > + { 0x3d49, 0x00 },
> > + { 0x3d4a, 0x85 },
> > + { 0x3d4b, 0x00 },
> > + { 0x3256, 0x01 },
> > + { 0x3758, 0xa3 },
> > + { 0x3759, 0x00 },
> > + { 0x375a, 0x85 },
> > + { 0x375b, 0x00 },
> > + { 0x3165, 0x00 },
> > + { 0x3169, 0x10 },
> > + { 0x316a, 0x02 },
> > + { 0x4174, 0x00 },
> > + { 0x3079, 0x08 },
> > + { 0x3090, 0x04 },
> > + { 0x3094, 0x04 },
> > + { 0x3098, 0x04 },
> > + { 0x309e, 0x04 },
> > + { 0x30a0, 0x04 },
> > + { 0x30a1, 0x3c },
> > + { 0x38a2, 0xf6 },
> > + { 0x40a2, 0x06 },
> > + { 0x38a3, 0x00 },
> > + { 0x30a4, 0x5f },
> > + { 0x30a8, 0x91 },
> > + { 0x30ac, 0x28 },
> > + { 0x30af, 0x09 },
> > + { 0x40c1, 0xf6 },
> > + { 0x40c7, 0x0f },
> > + { 0x31c8, 0xf3 },
> > + { 0x40c8, 0x00 },
> > + { 0x31d0, 0xf4 },
> > + { 0x30df, 0x00 },
> > +};
> > +
> > +static const struct imx296_regval imx296_1440_1088_settings[] = {
> > + { 0x300d, 0x00 },
> > + { 0x3010, 0xcb },
> > + { 0x3011, 0x08 },
> > + { 0x3014, 0x4c },
> > + { 0x3015, 0x04 },
> > + { 0x3300, 0x03 },
> > + { 0x3310, 0x08 },
> > + { 0x3311, 0x00 },
> > + { 0x3312, 0x00 },
> > + { 0x3313, 0x00 },
> > + { 0x3314, 0xa0 },
> > + { 0x3315, 0x05 },
> > + { 0x3316, 0x40 },
> > + { 0x3317, 0x04 },
> > +
> > + { 0x3204, 0x00 },
> > + { 0x3205, 0x00 },
> > + { 0x3212, 0x08 },
> > + { 0x3254, 0x3c },
> > + { 0x3255, 0x00 },
> > + { 0x3089, 0x80 },
> > + { 0x308a, 0x0b },
> > + { 0x308b, 0x80 },
> > + { 0x308c, 0x08 },
> > + { 0x418c, 0x74 },
> > + { 0x308d, 0x0e },
> > + { 0x308e, 0x00 },
> > + { 0x308f, 0x00 },
> > +};
> > +
> > +/* Mode configs */
> > +static const struct imx296_mode imx296_modes[] = {
> > + {
> > + .width = 1440,
> > + .height = 1088,
> > + .data = imx296_1440_1088_settings,
> > + .data_size = ARRAY_SIZE(imx296_1440_1088_settings),
> > + .pixel_rate = 80000000,
> > + },
> > +};
> > +
> > +static inline struct imx296 *to_imx296(struct v4l2_subdev *_sd)
> > +{
> > + return container_of(_sd, struct imx296, sd);
> > +}
> > +
> > +static inline int imx296_read_reg(struct imx296 *imx296, u16 addr, u8 *value)
> > +{
> > + unsigned int regval;
> > + int ret;
> > +
> > + ret = regmap_read(imx296->regmap, addr, &regval);
> > + if (ret) {
> > + dev_err(imx296->dev, "I2C read failed for addr: %x\n", addr);
> > + return ret;
> > + }
> > +
> > + *value = regval & 0xff;
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_write_reg(struct imx296 *imx296, u16 addr, u8 value)
> > +{
> > + int ret;
> > +
> > + ret = regmap_write(imx296->regmap, addr, value);
> > + if (ret) {
> > + dev_err(imx296->dev, "I2C write failed for addr: %x\n", addr);
> > + return ret;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int imx296_set_register_array(struct imx296 *imx296,
> > + const struct imx296_regval *settings,
> > + unsigned int num_settings)
> > +{
> > + unsigned int i;
> > + int ret;
> > +
> > + for (i = 0; i < num_settings; ++i, ++settings) {
> > + ret = imx296_write_reg(imx296, settings->reg, settings->val);
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Settle time is 10ms for all registers */
>
> Is this really needed? It'll take very long...
>

After digging into the datasheet, it looks like this delay can be moved out
of the loop. So it will become 10ms delay after setting all registers. I
misunderstood the reference driver earlier...

> > + msleep(10);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_write_buffered_reg(struct imx296 *imx296, u16 address_low,
> > + u8 nr_regs, u32 value)
> > +{
> > + unsigned int i;
> > + int ret;
> > +
> > + ret = imx296_write_reg(imx296, IMX296_REGHOLD, 0x01);
> > + if (ret) {
> > + dev_err(imx296->dev, "Error setting hold register\n");
> > + return ret;
> > + }
> > +
> > + for (i = 0; i < nr_regs; i++) {
> > + ret = imx296_write_reg(imx296, address_low + i,
> > + (u8)(value >> (i * 8)));
> > + if (ret) {
> > + dev_err(imx296->dev, "Error writing buffered registers\n");
> > + return ret;
> > + }
> > + }
> > +
> > + ret = imx296_write_reg(imx296, IMX296_REGHOLD, 0x00);
> > + if (ret) {
> > + dev_err(imx296->dev, "Error setting hold register\n");
> > + return ret;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int imx296_set_gain(struct imx296 *imx296, u32 value)
> > +{
> > + int ret;
> > +
> > + ret = imx296_write_buffered_reg(imx296, IMX296_GAIN_HIGH, 1,
> > + (u8)((value >> 8) & 0xFF));
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = imx296_write_buffered_reg(imx296, IMX296_GAIN_HIGH, 1,
>
> return ...
>
> > + (u8)((value) & 0xFF));
>
> You need neither casting nor and here as the value will be cast by
> imx296_write_buffered_reg() soon.
>

There is a mistake here as well. This should eventually be simplified
as below:

static inline int imx296_set_gain(struct imx296 *imx296, u32 value)
{
return imx296_write_buffered_reg(imx296, IMX296_GAIN_LOW, 2, value);
}

> > + if (ret < 0)
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > +/* Stop streaming */
> > +static int imx296_stop_streaming(struct imx296 *imx296)
> > +{
> > + int ret;
> > +
> > + ret = imx296_write_reg(imx296, IMX296_STANDBY, 0x01);
> > + if (ret < 0)
> > + return ret;
> > +
> > + msleep(30);
> > +
> > + return imx296_write_reg(imx296, IMX296_XMSTA, 0x01);
> > +}
> > +
> > +static int imx296_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + struct imx296 *imx296 = container_of(ctrl->handler,
> > + struct imx296, ctrls);
> > + int ret = 0;
> > +
> > + /* V4L2 controls values will be applied only when power is already up */
> > + if (!pm_runtime_get_if_in_use(imx296->dev))
> > + return 0;
> > +
> > + switch (ctrl->id) {
> > + case V4L2_CID_GAIN:
> > + ret = imx296_set_gain(imx296, ctrl->val);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + pm_runtime_put(imx296->dev);
> > +
> > + return ret;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops imx296_ctrl_ops = {
> > + .s_ctrl = imx296_set_ctrl,
> > +};
> > +
> > +static int imx296_enum_mbus_code(struct v4l2_subdev *sd,
> > + struct v4l2_subdev_pad_config *cfg,
> > + struct v4l2_subdev_mbus_code_enum *code)
> > +{
> > + code->code = IMX296_DEFAULT_FORMAT;
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_get_fmt(struct v4l2_subdev *sd,
> > + struct v4l2_subdev_pad_config *cfg,
> > + struct v4l2_subdev_format *fmt)
> > +{
> > + struct imx296 *imx296 = to_imx296(sd);
> > + struct v4l2_mbus_framefmt *framefmt;
> > +
> > + mutex_lock(&imx296->lock);
> > +
> > + if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > + framefmt = v4l2_subdev_get_try_format(&imx296->sd, cfg,
> > + fmt->pad);
> > + else
> > + framefmt = &imx296->current_format;
> > +
> > + fmt->format = *framefmt;
> > +
> > + mutex_unlock(&imx296->lock);
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_set_fmt(struct v4l2_subdev *sd,
> > + struct v4l2_subdev_pad_config *cfg,
> > + struct v4l2_subdev_format *fmt)
> > +{
> > + struct imx296 *imx296 = to_imx296(sd);
> > + const struct imx296_mode *mode;
> > + struct v4l2_mbus_framefmt *format;
> > + int ret = 0;
> > +
> > + mutex_lock(&imx296->lock);
> > +
> > + mode = v4l2_find_nearest_size(imx296_modes,
> > + ARRAY_SIZE(imx296_modes),
> > + width, height,
> > + fmt->format.width, fmt->format.height);
> > +
> > + fmt->format.width = mode->width;
> > + fmt->format.height = mode->height;
> > +
> > + fmt->format.code = IMX296_DEFAULT_FORMAT;
> > + fmt->format.field = V4L2_FIELD_NONE;
> > +
> > + if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
> > + format = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
> > + } else {
> > + format = &imx296->current_format;
> > + __v4l2_ctrl_s_ctrl_int64(imx296->pixel_rate, mode->pixel_rate);
> > +
> > + imx296->current_mode = mode;
> > + }
> > +
> > + *format = fmt->format;
> > +
> > + mutex_unlock(&imx296->lock);
> > +
> > + return ret;
> > +}
> > +
> > +static int imx296_entity_init_cfg(struct v4l2_subdev *subdev,
> > + struct v4l2_subdev_pad_config *cfg)
> > +{
> > + struct v4l2_subdev_format fmt = { 0 };
> > +
> > + fmt.which = cfg ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
> > + fmt.format.width = 1440;
> > + fmt.format.height = 1088;
> > +
> > + imx296_set_fmt(subdev, cfg, &fmt);
> > +
> > + return 0;
> > +}
> > +
> > +/* Start streaming */
> > +static int imx296_start_streaming(struct imx296 *imx296)
> > +{
> > + int ret;
> > +
> > + /* Set init register settings */
> > + ret = imx296_set_register_array(imx296, imx296_global_init_settings,
> > + ARRAY_SIZE(imx296_global_init_settings));
> > + if (ret < 0) {
> > + dev_err(imx296->dev, "Could not set init registers\n");
> > + return ret;
> > + }
> > +
> > + /* Apply default values of current mode */
> > + ret = imx296_set_register_array(imx296, imx296->current_mode->data,
> > + imx296->current_mode->data_size);
> > + if (ret < 0) {
> > + dev_err(imx296->dev, "Could not set current mode\n");
> > + return ret;
> > + }
> > +
> > + /* Apply customized values from user */
> > + ret = v4l2_ctrl_handler_setup(imx296->sd.ctrl_handler);
> > + if (ret) {
> > + dev_err(imx296->dev, "Could not sync v4l2 controls\n");
> > + return ret;
> > + }
> > +
> > + ret = imx296_write_reg(imx296, IMX296_STANDBY, 0x00);
> > + if (ret < 0)
> > + return ret;
> > +
> > + msleep(30);
> > +
> > + /* Start streaming */
> > + return imx296_write_reg(imx296, IMX296_XMSTA, 0x00);
> > +}
> > +
> > +static int imx296_set_stream(struct v4l2_subdev *sd, int enable)
> > +{
> > + struct imx296 *imx296 = to_imx296(sd);
> > + int ret;
> > +
> > + if (enable) {
> > + ret = pm_runtime_get_sync(imx296->dev);
> > + if (ret < 0) {
> > + pm_runtime_put_noidle(imx296->dev);
> > + return ret;
> > + }
> > +
> > + ret = imx296_start_streaming(imx296);
> > + if (ret) {
> > + dev_err(imx296->dev, "Start stream failed\n");
> > + pm_runtime_put(imx296->dev);
> > + return ret;
> > + }
> > + } else {
> > + imx296_stop_streaming(imx296);
> > + pm_runtime_put(imx296->dev);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_get_regulators(struct device *dev, struct imx296 *imx296)
> > +{
> > + unsigned int i;
> > +
> > + for (i = 0; i < IMX296_NUM_SUPPLIES; i++)
> > + imx296->supplies[i].supply = imx296_supply_name[i];
> > +
> > + return devm_regulator_bulk_get(dev, IMX296_NUM_SUPPLIES,
> > + imx296->supplies);
> > +}
> > +
> > +static int imx296_power_on(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct imx296 *imx296 = to_imx296(sd);
> > + int ret;
> > +
> > + ret = regulator_bulk_enable(IMX296_NUM_SUPPLIES, imx296->supplies);
> > + if (ret) {
> > + dev_err(imx296->dev, "Failed to enable regulators\n");
> > + return ret;
> > + }
> > +
> > + usleep_range(1, 2);
> > +
> > + gpiod_set_value_cansleep(imx296->rst_gpio, 1);
> > +
> > + usleep_range(1, 2);
> > +
> > + ret = clk_prepare_enable(imx296->mclk);
> > + if (ret) {
> > + dev_err(imx296->dev, "Failed to enable clock\n");
> > + return ret;
> > + }
> > +
> > + usleep_range(30000, 31000);
> > +
> > + return 0;
> > +}
> > +
> > +static int imx296_power_off(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct imx296 *imx296 = to_imx296(sd);
> > +
> > + clk_disable_unprepare(imx296->mclk);
> > + gpiod_set_value_cansleep(imx296->rst_gpio, 0);
> > + regulator_bulk_disable(IMX296_NUM_SUPPLIES, imx296->supplies);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct dev_pm_ops imx296_pm_ops = {
> > + SET_RUNTIME_PM_OPS(imx296_power_on, imx296_power_off, NULL)
> > +};
> > +
> > +static const struct v4l2_subdev_video_ops imx296_video_ops = {
> > + .s_stream = imx296_set_stream,
> > +};
> > +
> > +static const struct v4l2_subdev_pad_ops imx296_pad_ops = {
> > + .init_cfg = imx296_entity_init_cfg,
> > + .enum_mbus_code = imx296_enum_mbus_code,
> > + .get_fmt = imx296_get_fmt,
> > + .set_fmt = imx296_set_fmt,
> > +};
> > +
> > +static const struct v4l2_subdev_ops imx296_subdev_ops = {
> > + .video = &imx296_video_ops,
> > + .pad = &imx296_pad_ops,
> > +};
> > +
> > +static const struct media_entity_operations imx296_subdev_entity_ops = {
> > + .link_validate = v4l2_subdev_link_validate,
> > +};
> > +
> > +static int imx296_probe(struct i2c_client *client)
> > +{
> > + struct device *dev = &client->dev;
> > + struct fwnode_handle *endpoint;
> > + struct imx296 *imx296;
> > + u32 mclk_freq;
> > + int ret;
> > +
> > + imx296 = devm_kzalloc(dev, sizeof(*imx296), GFP_KERNEL);
> > + if (!imx296)
> > + return -ENOMEM;
> > +
> > + imx296->dev = dev;
> > + imx296->regmap = devm_regmap_init_i2c(client, &imx296_regmap_config);
> > + if (IS_ERR(imx296->regmap)) {
> > + dev_err(dev, "Unable to initialize I2C\n");
> > + return -ENODEV;
> > + }
> > +
> > + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
> > + if (!endpoint) {
> > + dev_err(dev, "Endpoint node not found\n");
> > + return -EINVAL;
> > + }
> > +
> > + ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &imx296->ep);
>
> Please allocate ep in stack instead, there's no need to keep it around
> further as the driver doesn't use it. Also initialise the bus_type field;
> support for figuring it out is there just for old drivers.
>

Makes sense!

> > + fwnode_handle_put(endpoint);
> > + if (ret) {
> > + dev_err(dev, "Parsing endpoint node failed\n");
> > + goto free_err;
> > + }
> > +
> > + /* Only CSI2 is supported for now */
> > + if (imx296->ep.bus_type != V4L2_MBUS_CSI2_DPHY) {
>
> After setting the bus_type field, you can omit this check.
>
> > + dev_err(dev, "Unsupported bus type, should be CSI2\n");
> > + ret = -EINVAL;
> > + goto free_err;
> > + }
> > +
> > + /* Set default mode to max resolution */
> > + imx296->current_mode = &imx296_modes[0];
> > +
> > + /* get system clock (mclk) */
> > + imx296->mclk = devm_clk_get(dev, "mclk");
> > + if (IS_ERR(imx296->mclk)) {
> > + dev_err(dev, "Could not get mclk");
> > + ret = PTR_ERR(imx296->mclk);
> > + goto free_err;
> > + }
> > +
> > + ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > + &mclk_freq);
> > + if (ret) {
> > + dev_err(dev, "Could not get mclk frequency\n");
> > + goto free_err;
> > + }
> > +
> > + /* external clock must be 37.125 MHz */
> > + if (mclk_freq != 37125000) {
> > + dev_err(dev, "External clock frequency %u is not supported\n",
> > + mclk_freq);
> > + ret = -EINVAL;
> > + goto free_err;
> > + }
> > +
> > + ret = clk_set_rate(imx296->mclk, mclk_freq);
> > + if (ret) {
> > + dev_err(dev, "Could not set mclk frequency\n");
> > + goto free_err;
> > + }
> > +
> > + ret = imx296_get_regulators(dev, imx296);
> > + if (ret < 0) {
> > + dev_err(dev, "Cannot get regulators\n");
> > + goto free_err;
> > + }
> > +
> > + imx296->rst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS);
> > + if (IS_ERR(imx296->rst_gpio)) {
> > + dev_err(dev, "Cannot get reset gpio\n");
> > + ret = PTR_ERR(imx296->rst_gpio);
> > + goto free_err;
> > + }
> > +
> > + mutex_init(&imx296->lock);
> > +
> > + v4l2_ctrl_handler_init(&imx296->ctrls, 3);
> > +
> > + v4l2_ctrl_new_std(&imx296->ctrls, &imx296_ctrl_ops,
> > + V4L2_CID_GAIN, 0, 72, 1, 0);
> > +
> > + imx296->pixel_rate = v4l2_ctrl_new_std(&imx296->ctrls, &imx296_ctrl_ops,
> > + V4L2_CID_PIXEL_RATE, 1,
> > + INT_MAX, 1,
> > + imx296_modes[0].pixel_rate);
> > +
> > + imx296->sd.ctrl_handler = &imx296->ctrls;
> > +
> > + if (imx296->ctrls.error) {
> > + dev_err(dev, "Control initialization error %d\n",
> > + imx296->ctrls.error);
> > + ret = imx296->ctrls.error;
> > + goto free_ctrl;
> > + }
> > +
> > + v4l2_i2c_subdev_init(&imx296->sd, client, &imx296_subdev_ops);
> > + imx296->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > + imx296->sd.dev = &client->dev;
> > + imx296->sd.entity.ops = &imx296_subdev_entity_ops;
> > + imx296->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +
> > + imx296->pad.flags = MEDIA_PAD_FL_SOURCE;
> > + ret = media_entity_pads_init(&imx296->sd.entity, 1, &imx296->pad);
> > + if (ret < 0) {
> > + dev_err(dev, "Could not register media entity\n");
> > + goto free_ctrl;
> > + }
> > +
> > + ret = v4l2_async_register_subdev(&imx296->sd);
> > + if (ret < 0) {
> > + dev_err(dev, "Could not register v4l2 device\n");
> > + goto free_entity;
> > + }
> > +
> > + /* Power on the device to match runtime PM state below */
> > + ret = imx296_power_on(dev);
> > + if (ret < 0) {
> > + dev_err(dev, "Could not power on the device\n");
> > + goto free_entity;
> > + }
> > +
> > + pm_runtime_set_active(dev);
> > + pm_runtime_enable(dev);
> > + pm_runtime_idle(dev);
> > +
> > + v4l2_fwnode_endpoint_free(&imx296->ep);
> > +
> > + return 0;
> > +
> > +free_entity:
> > + media_entity_cleanup(&imx296->sd.entity);
> > +free_ctrl:
> > + v4l2_ctrl_handler_free(&imx296->ctrls);
> > + mutex_destroy(&imx296->lock);
> > +free_err:
> > + v4l2_fwnode_endpoint_free(&imx296->ep);
> > +
> > + return ret;
> > +}
> > +
> > +static int imx296_remove(struct i2c_client *client)
> > +{
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct imx296 *imx296 = to_imx296(sd);
> > +
> > + v4l2_async_unregister_subdev(sd);
> > + media_entity_cleanup(&sd->entity);
> > + v4l2_ctrl_handler_free(sd->ctrl_handler);
> > +
> > + mutex_destroy(&imx296->lock);
> > +
> > + pm_runtime_disable(imx296->dev);
> > + if (!pm_runtime_status_suspended(imx296->dev))
> > + imx296_power_off(imx296->dev);
> > + pm_runtime_set_suspended(imx296->dev);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id imx296_of_match[] = {
> > + { .compatible = "sony,imx296" },
> > + { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, imx296_of_match);
> > +
> > +static struct i2c_driver imx296_i2c_driver = {
> > + .probe_new = imx296_probe,
> > + .remove = imx296_remove,
> > + .driver = {
> > + .name = "imx296",
> > + .pm = &imx296_pm_ops,
> > + .of_match_table = of_match_ptr(imx296_of_match),
>
> No need for of_match_ptr here.
>

AFAIK, of_match_ptr is needed for !OF case. Else we need to manually add
#ifdef clut to make it NULL. Does the situation changed now?

Thanks,
Mani

> > + },
> > +};
> > +
> > +module_i2c_driver(imx296_i2c_driver);
> > +
> > +MODULE_DESCRIPTION("Sony IMX296 CMOS Image Sensor Driver");
> > +MODULE_AUTHOR("FRAMOS GmbH");
> > +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>");
> > +MODULE_LICENSE("GPL v2");
>
> --
> Kind regards,
>
> Sakari Ailus