Re: [PATCH v3 2/2] Add support for Omnivision OV5647

[Pavel Machek <pavel@ucw.cz>]

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Hi!

> +/*
> + * A V4L2 driver for OmniVision OV5647 cameras.
> + *
> + * Based on Samsung S5K6AAFX SXGA 1/6" 1.3M CMOS Image Sensor driver
> + * Copyright (C) 2011 Sylwester Nawrocki <s.nawrocki@samsung.com>
> + *
> + * Based on Omnivision OV7670 Camera Driver
> + * Copyright (C) 2006-7 Jonathan Corbet <corbet@lwn.net>
> + *
> + * Copyright (C) 2016, Synopsys, Inc.
> + *
> + */

If you do copyrights, you should also specify license.

> +static bool debug;
> +module_param(debug, bool, 0644);
> +MODULE_PARM_DESC(debug, "Debug level (0-1)");

Please remove, we have generic infrastructure for debugging.

> +/*
> + * The ov5647 sits on i2c with ID 0x6c
> + */
> +#define OV5647_I2C_ADDR 0x6c
> +#define SENSOR_NAME "ov5647"
> +
> +#define OV5647_REG_CHIPID_H	0x300A
> +#define OV5647_REG_CHIPID_L	0x300B
> +
> +#define REG_TERM 0xfffe
> +#define VAL_TERM 0xfe
> +#define REG_DLY  0xffff
> +
> +/*define the voltage level of control signal*/

"/* ", " */".

> +#define CSI_STBY_ON		1
> +#define CSI_STBY_OFF		0
> +#define CSI_RST_ON		0
> +#define CSI_RST_OFF		1
> +#define CSI_PWR_ON		1
> +#define CSI_PWR_OFF		0
> +#define CSI_AF_PWR_ON		1
> +#define CSI_AF_PWR_OFF		0
...
> +enum power_seq_cmd {
> +	CSI_SUBDEV_PWR_OFF = 0x00,
> +	CSI_SUBDEV_PWR_ON = 0x01,
> +};

Pick one style for defines/enums?

> +struct regval_list {
> +	uint16_t addr;
> +	uint8_t data;
> +};

u8/u16?

> +/**
> +* @short I2C Write operation
> +* @param[in] i2c_client I2C client
> +* @param[in] reg register address
> +* @param[in] val value to write
> +* @return Error code
> +*/

" *"?

> +static int ov5647_write(struct v4l2_subdev *sd, uint16_t reg, uint8_t val)
> +{
> +	int ret;
> +	unsigned char data[3] = { reg >> 8, reg & 0xff, val};

" }".

> +static int ov5647_write_array(struct v4l2_subdev *subdev,
> +				struct regval_list *regs, int array_size)
> +{
> +	int i = 0;
> +	int ret = 0;
> +
> +	if (!regs)
> +		return -EINVAL;
> +
> +	while (i < array_size) {
> +		if (regs->addr == REG_DLY)
> +			mdelay(regs->data);
> +		else
> +			ret = ov5647_write(subdev, regs->addr, regs->data);

The "REG_DLY" is never used AFAICT? Remove?

> +		if (ret == -EIO)
> +			return ret;
> +

ov5647_write() can return errors other then EIO. Are they handled correctly?

> +/**
> + * @short Set SW standby
> + * @param[in] subdev v4l2 subdev
> + * @param[in] on_off standby on or off
> + * @return Error code
> + */
> +static int sensor_s_sw_stby(struct v4l2_subdev *subdev, int on_off)
> +{
> +	int ret;
> +	unsigned char rdval;
> +
> +	ret = ov5647_read(subdev, 0x0100, &rdval);
> +	if (ret != 0)
> +		return ret;
> +
> +	if (on_off == CSI_STBY_ON)
> +		ret = ov5647_write(subdev, 0x0100, rdval&0xfe);
> +
> +	else
> +		ret = ov5647_write(subdev, 0x0100, rdval|0x01);

I'd get rid of CSI_STBY_ON, and convert arg to bool, as you don't
really handle other values. Plus, naming it "set_sw_standby()" would
make core slightly more readable. Also kill the empty line before
else.

> +/**
> +* @short Initialize sensor
> +* @param[in] subdev v4l2 subdev
> +* @param[in] val not used
> +* @return Error code
> +*/
> +static int __sensor_init(struct v4l2_subdev *subdev)
> +{
> +	int ret;
> +	uint8_t resetval;
> +	unsigned char rdval;

u8 for both?

> +	ov5647_read(subdev, 0x0100, &resetval);
> +		if (!resetval&0x01) {
> +			v4l2_dbg(1, debug, subdev,
> +					"DEVICE WAS IN SOFTWARE STANDBY");

No shouting please? If it is important maybe it should have higher
priority?

> +static int sensor_power(struct v4l2_subdev *subdev, int on)
> +{
> +	int ret;
> +	struct ov5647 *ov5647 = to_state(subdev);
> +
> +	ret = 0;
> +	mutex_lock(&ov5647->lock);
> +
> +	switch (on) {
> +	case CSI_SUBDEV_PWR_OFF:
...
> +	case CSI_SUBDEV_PWR_ON:
...
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	mutex_unlock(&ov5647->lock);

I'd really convert this to bool. Note how it returns with lock held?


> +int ov5647_detect(struct v4l2_subdev *sd)
> +{
> +	unsigned char v;
> +	int ret;
> +
> +	ret = sensor_power(sd, 1);
> +	if (ret < 0)
> +		return ret;
> +	ret = ov5647_read(sd, OV5647_REG_CHIPID_H, &v);
> +	if (ret < 0)
> +		return ret;
> +	if (v != 0x56) /* OV manuf. id. */
> +		return -ENODEV;
> +	ret = ov5647_read(sd, OV5647_REG_CHIPID_L, &v);
> +	if (ret < 0)
> +		return ret;
> +	if (v != 0x47)
> +		return -ENODEV;

I guess invalid chipid deserves a printk?

> +* Refer to Linux errors.

Useful?

> +/**
> +* @short of_device_id structure
> +*/
> +static const struct i2c_device_id ov5647_id[] = {

Umm. The comment looks useless and wrong.

Best regards,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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