Re: [PATCH] media: Add a driver for the ov5645 camera sensor.

[Stanimir Varbanov <stanimir.varbanov@linaro.org>]

Hi Todor,

On 05/12/2016 05:59 PM, Todor Tomov wrote:
> The ov5645 sensor from Omnivision supports up to 2592x1944
> and CSI2 interface.
> 
> The driver adds support for the following modes:
> - 1280x960
> - 1920x1080
> - 2592x1944
> 
> Output format is packed 8bit UYVY.
> 
> Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
> ---
>  .../devicetree/bindings/media/i2c/ov5645.txt       |   54 +
>  drivers/media/i2c/Kconfig                          |   11 +
>  drivers/media/i2c/Makefile                         |    1 +
>  drivers/media/i2c/ov5645.c                         | 1344 ++++++++++++++++++++
>  4 files changed, 1410 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5645.txt
>  create mode 100644 drivers/media/i2c/ov5645.c
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.txt b/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> new file mode 100644
> index 0000000..1d65fa8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/ov5645.txt

The binding doc should be a separate patch. Also you should add
devicetree ML in cc.

> @@ -0,0 +1,54 @@
> +* Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor
> +
> +The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image sensor with
> +an active array size of 2592H x 1944V. It is programmable through a serial SCCB
> +interface.
> +
> +Required Properties:
> +- compatible: value should be "ovti,ov5645"
> +- clocks: reference to the xclk clock
> +- clock-names: should be "xclk"
> +- clock-rates: the xclk clock frequency
> +
> +Optional Properties:
> +- reset-gpio: Chip reset GPIO
> +- pwdn-gpio: Chip power down GPIO
> +- DOVDD-supply: Chip IO regulator
> +- DVDD-supply: Chip core regulator
> +- AVDD-supply: Chip analog regulator

I'd use lower-case for the -supply properties

<cut>

> diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> new file mode 100644
> index 0000000..bae07e4
> --- /dev/null
> +++ b/drivers/media/i2c/ov5645.c
> @@ -0,0 +1,1344 @@
> +/*
> + * Driver for the OV5645 camera sensor.
> + *
> + * Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
> + * Copyright (C) 2015 By Tech Design S.L. All Rights Reserved.
> + * Copyright (C) 2012-2013 Freescale Semiconductor, Inc. All Rights Reserved.
> + *
> + * Based on:
> + * - the OV5645 driver from QC msm-3.10 kernel on codeaurora.org:
> + *   https://us.codeaurora.org/cgit/quic/la/kernel/msm-3.10/tree/drivers/
> + *       media/platform/msm/camera_v2/sensor/ov5645.c?h=LA.BR.1.2.4_rb1.41
> + * - the OV5640 driver posted on linux-media:
> + *   https://www.mail-archive.com/linux-media%40vger.kernel.org/msg92671.html
> + */
> +
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> +
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/ctype.h>

do you need ctype.h really ?

> +#include <linux/types.h>
> +#include <linux/gpio.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>

those two includes are useless.

> +#include <media/v4l2-subdev.h>
> +#include <media/v4l2-of.h>
> +#include <media/v4l2-ctrls.h>
> +
> +#define OV5645_VOLTAGE_ANALOG               2800000
> +#define OV5645_VOLTAGE_DIGITAL_CORE         1500000
> +#define OV5645_VOLTAGE_DIGITAL_IO           1800000
> +
> +#define OV5645_XCLK_MIN 6000000
> +#define OV5645_XCLK_MAX 24000000
> +
> +#define OV5645_SYSTEM_CTRL0		0x3008
> +#define		OV5645_SYSTEM_CTRL0_START	0x02
> +#define		OV5645_SYSTEM_CTRL0_STOP	0x42
> +#define OV5645_CHIP_ID_HIGH_REG		0x300A
> +#define		OV5645_CHIP_ID_HIGH		0x56
> +#define OV5645_CHIP_ID_LOW_REG		0x300B
> +#define		OV5645_CHIP_ID_LOW		0x45
> +#define OV5645_AWB_MANUAL_CONTROL	0x3406
> +#define		OV5645_AWB_MANUAL_ENABLE	(1 << 0)

use BIT(x) here and below for bit operations

> +#define OV5645_AEC_PK_MANUAL		0x3503
> +#define		OV5645_AEC_MANUAL_ENABLE	(1 << 0)
> +#define		OV5645_AGC_MANUAL_ENABLE	(1 << 1)
> +#define OV5645_TIMING_TC_REG20		0x3820
> +#define		OV5645_SENSOR_VFLIP		(1 << 1)
> +#define		OV5645_ISP_VFLIP		(1 << 2)
> +#define OV5645_TIMING_TC_REG21		0x3821
> +#define		OV5645_SENSOR_MIRROR		(1 << 1)
> +#define OV5645_PRE_ISP_TEST_SETTING_1	0x503d
> +#define		OV5645_TEST_PATTERN_MASK	0x3
> +#define		OV5645_SET_TEST_PATTERN(x)	((x) & OV5645_TEST_PATTERN_MASK)
> +#define		OV5645_TEST_PATTERN_ENABLE	(1 << 7)
> +#define OV5645_SDE_SAT_U		0x5583
> +#define OV5645_SDE_SAT_V		0x5584
> +
> +enum ov5645_mode {
> +	ov5645_mode_min = 0,
> +	ov5645_mode_sxga_1280_960 = 0,
> +	ov5645_mode_1080p_1920_1080 = 1,
> +	ov5645_mode_full_2592_1944 = 2,
> +	ov5645_mode_max = 2,

I'd make enums upper-case and rename them to OV5645_MODE_SXGA,
OV5645_FULLHD, OV5645_FULL or something similar ?

> +};
> +
> +struct reg_value {
> +	u16 reg;
> +	u8 val;
> +};
> +
> +struct ov5645_mode_info {
> +	enum ov5645_mode mode;
> +	u32 width;
> +	u32 height;
> +	struct reg_value *init_data_ptr;
> +	u32 init_data_size;
> +};
> +
> +struct ov5645 {
> +	struct i2c_client *i2c_client;
> +	struct device *dev;
> +	struct v4l2_subdev sd;
> +	struct media_pad pad;
> +	struct v4l2_of_endpoint ep;
> +	struct v4l2_mbus_framefmt fmt;
> +	struct v4l2_rect crop;

just rect?

> +	struct clk *xclk;
> +	int xclk_freq;

unsigned long xclk_freq

> +
> +	struct regulator *io_regulator;
> +	struct regulator *core_regulator;
> +	struct regulator *analog_regulator;
> +
> +	enum ov5645_mode current_mode;
> +
> +	/* Cached control values */
> +	struct v4l2_ctrl_handler ctrls;
> +	struct v4l2_ctrl *saturation;
> +	struct v4l2_ctrl *hflip;
> +	struct v4l2_ctrl *vflip;
> +	struct v4l2_ctrl *autogain;
> +	struct v4l2_ctrl *autoexposure;
> +	struct v4l2_ctrl *awb;
> +	struct v4l2_ctrl *pattern;
> +
> +	struct mutex power_lock; /* lock to protect power_count */
> +	int power_count;
> +
> +	int pwdn_gpio;
> +	int rst_gpio;
> +};
> +
> +static inline struct ov5645 *to_ov5645(struct v4l2_subdev *sd)
> +{
> +	return container_of(sd, struct ov5645, sd);
> +}
> +
> +static struct reg_value ov5645_global_init_setting[] = {
> +	{0x3103, 0x11,},

could you add spaces and remove trailing comma?

<cut>

> +static struct ov5645_mode_info ov5645_mode_info_data[ov5645_mode_max + 1] = {
> +	{ov5645_mode_sxga_1280_960, 1280, 960,
> +	 ov5645_setting_sxga,
> +	 ARRAY_SIZE(ov5645_setting_sxga)},
> +	{ov5645_mode_1080p_1920_1080, 1920, 1080,
> +	 ov5645_setting_1080P,
> +	 ARRAY_SIZE(ov5645_setting_1080P)},
> +	{ov5645_mode_full_2592_1944, 2592, 1944,
> +	 ov5645_setting_full,
> +	 ARRAY_SIZE(ov5645_setting_full)},
> +};
> +

could you format this better.

> +static void ov5645_regulators_get(struct ov5645 *ov5645)
> +{
> +	ov5645->io_regulator = devm_regulator_get(ov5645->dev, "DOVDD");

could you move all devm_regulator_get calls in .probe

> +	if (IS_ERR(ov5645->io_regulator)) {
> +		ov5645->io_regulator = NULL;

this can be EPROBE_DEFER, so you should take care and check the exact
error code.

> +		dev_dbg(ov5645->dev, "cannot get io voltage\n");
> +	} else {
> +		regulator_set_voltage(ov5645->io_regulator,
> +				OV5645_VOLTAGE_DIGITAL_IO,
> +				OV5645_VOLTAGE_DIGITAL_IO);

error check for regulator_set_voltage?

<cut>


> +
> +static void ov5645_regulators_disable(struct ov5645 *ov5645)
> +{
> +	if (ov5645->analog_regulator)
> +		regulator_disable(ov5645->analog_regulator);

regulator_disable return error, check it

> +	if (ov5645->core_regulator)
> +		regulator_disable(ov5645->core_regulator);
> +	if (ov5645->io_regulator)
> +		regulator_disable(ov5645->io_regulator);
> +}
> +
> +static s32 ov5645_write_reg(struct ov5645 *ov5645, u16 reg, u8 val)
> +{
> +	u8 regbuf[3] = {0};

you set all elements below, so no need to zeroing.

> +
> +	regbuf[0] = reg >> 8;
> +	regbuf[1] = reg & 0xff;
> +	regbuf[2] = val;
> +
> +	if (i2c_master_send(ov5645->i2c_client, regbuf, 3) < 0) {
> +		dev_err(ov5645->dev, "%s:write reg error:reg=%x,val=%x\n",
> +			__func__, reg, val);
> +		return -1;

return the exact error from i2c_master_send()

> +	}
> +
> +	return 0;
> +}
> +
> +static s32 ov5645_read_reg(struct ov5645 *ov5645, u16 reg, u8 *val)
> +{
> +	u8 regbuf[2] = {0};

no need to zero the array

> +	u8 tmpval = 0;
> +
> +	regbuf[0] = reg >> 8;
> +	regbuf[1] = reg & 0xff;
> +
> +	if (i2c_master_send(ov5645->i2c_client, regbuf, 2) != 2) {
> +		dev_err(ov5645->dev, "%s:write reg error:reg=%x\n",
> +			__func__, reg);
> +		return -1;
> +	}
> +
> +	if (i2c_master_recv(ov5645->i2c_client, &tmpval, 1) != 1) {
> +		dev_err(ov5645->dev, "%s:read reg error:reg=%x,val=%x\n",
> +			__func__, reg, tmpval);
> +		return -1;
> +	}
> +

again, return the exact error from i2c_master

> +	*val = tmpval;
> +
> +	return tmpval;

return zero or the i2c_master error code.

> +}
> +
> +static int ov5645_set_aec_mode(struct ov5645 *ov5645, u32 mode)
> +{
> +	u8 val;
> +
> +	ov5645_read_reg(ov5645, OV5645_AEC_PK_MANUAL, &val);
> +	if (mode == V4L2_EXPOSURE_AUTO) {
> +		val |= OV5645_AEC_MANUAL_ENABLE;
> +	} else { /* V4L2_EXPOSURE_MANUAL */

wrong comment, just remove it

> +		val &= ~OV5645_AEC_MANUAL_ENABLE;
> +	}
> +
> +	dev_dbg(ov5645->dev, "%s: mode = %d\n", __func__, mode);
> +
> +	return ov5645_write_reg(ov5645, OV5645_AEC_PK_MANUAL, val);
> +}
> +
> +static int ov5645_set_agc_mode(struct ov5645 *ov5645, u32 enable)
> +{
> +	u8 val;
> +
> +	ov5645_read_reg(ov5645, OV5645_AEC_PK_MANUAL, &val);
> +	if (!enable)
> +		val |= OV5645_AGC_MANUAL_ENABLE;
> +	else
> +		val &= ~OV5645_AGC_MANUAL_ENABLE;
> +
> +	dev_dbg(ov5645->dev, "%s: enable = %d\n", __func__, enable);
> +
> +	return ov5645_write_reg(ov5645, OV5645_AEC_PK_MANUAL, val);
> +}
> +
> +static int ov5645_set_register_array(struct ov5645 *ov5645,
> +				     struct reg_value *settings,
> +				     s32 num_settings)

unsigned int num_settings

> +{
> +	register u16 reg = 0;

'register' ? The compiler is smart enough.

> +	register u8 val = 0;

no need to init val variable

> +	int i, ret = 0;

unsigned int i

> +
> +	for (i = 0; i < num_settings; ++i, ++settings) {
> +		reg = settings->reg;
> +		val = settings->val;
> +
> +		ret = ov5645_write_reg(ov5645, reg, val);
> +		if (ret < 0)
> +			goto err;
> +	}
> +err:
> +	return ret;
> +}
> +
> +static int ov5645_init(struct ov5645 *ov5645)
> +{
> +	struct reg_value *settings = NULL;
> +	int num_settings = 0;

no need to initialize *settings and num_settings variables

> +	int ret;
> +
> +	settings = ov5645_global_init_setting;
> +	num_settings = ARRAY_SIZE(ov5645_global_init_setting);
> +	ret = ov5645_set_register_array(ov5645, settings, num_settings);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int ov5645_change_mode(struct ov5645 *ov5645, enum ov5645_mode mode)
> +{
> +	struct reg_value *settings = NULL;
> +	s32 num_settings = 0;
> +	int ret = 0;
> +
> +	settings = ov5645_mode_info_data[mode].init_data_ptr;
> +	num_settings = ov5645_mode_info_data[mode].init_data_size;
> +	ret = ov5645_set_register_array(ov5645, settings, num_settings);
> +
> +	return ret;
> +}
> +
> +static void __ov5645_set_power(struct ov5645 *ov5645, bool on)

I personally do not like __* prefix for functions in drivers.

> +{
> +	dev_dbg(ov5645->dev, "%s: on = %d\n", __func__, on);
> +
> +	if (on) {
> +		clk_prepare_enable(ov5645->xclk);
> +		ov5645_regulators_enable(ov5645);

check for errors, please.

> +		usleep_range(5000, 15000);
> +		if (ov5645->pwdn_gpio)
> +			gpio_set_value(ov5645->pwdn_gpio, 1);
> +		usleep_range(1000, 2000);
> +		if (ov5645->rst_gpio)
> +			gpio_set_value(ov5645->rst_gpio, 1);
> +		msleep(20);
> +	} else {
> +		if (ov5645->rst_gpio)
> +			gpio_set_value(ov5645->rst_gpio, 0);
> +		if (ov5645->pwdn_gpio)
> +			gpio_set_value(ov5645->pwdn_gpio, 0);
> +		ov5645_regulators_disable(ov5645);
> +		clk_disable_unprepare(ov5645->xclk);
> +	}
> +}
> +

<cut>

> +
> +static int ov5645_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct device_node *endpoint;
> +	struct ov5645 *ov5645;
> +	int ret = 0;
> +
> +	ov5645 = devm_kzalloc(dev, sizeof(struct ov5645), GFP_KERNEL);
> +	if (!ov5645)
> +		return -ENOMEM;
> +
> +	ov5645->i2c_client = client;
> +	ov5645->dev = dev;
> +	ov5645->fmt.code = MEDIA_BUS_FMT_UYVY8_2X8;
> +	ov5645->fmt.width = 1920;
> +	ov5645->fmt.height = 1080;
> +	ov5645->fmt.field = V4L2_FIELD_NONE;
> +	ov5645->current_mode = ov5645_mode_1080p_1920_1080;
> +
> +	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
> +	if (!endpoint) {
> +		dev_err(dev, "endpoint node not found\n");
> +		return -EINVAL;
> +	}
> +
> +	v4l2_of_parse_endpoint(endpoint, &ov5645->ep);

check for errors?

> +	if (ov5645->ep.bus_type != V4L2_MBUS_CSI2) {
> +		dev_err(dev, "invalid bus type, must be CSI2\n");
> +		of_node_put(endpoint);
> +		return -EINVAL;
> +	}
> +	of_node_put(endpoint);
> +
> +	/* get system clock (xclk) frequency */
> +	ret = of_property_read_u32(dev->of_node, "clock-rates",
> +				   &ov5645->xclk_freq);
> +	if (!ret) {
> +		if (ov5645->xclk_freq < OV5645_XCLK_MIN ||
> +		    ov5645->xclk_freq > OV5645_XCLK_MAX) {
> +			dev_err(dev, "invalid xclk frequency: %d\n",
> +				ov5645->xclk_freq);
> +			return -EINVAL;

why not just clamp the xclk_freq, and contunue ...

> +		}
> +	}
> +
> +	/* get system clock (xclk) */
> +	ov5645->xclk = devm_clk_get(dev, "xclk");
> +	if (IS_ERR(ov5645->xclk)) {
> +		dev_err(dev, "could not get xclk");
> +		return -EINVAL;

just return the error from devm_clk_get

> +	}
> +	clk_set_rate(ov5645->xclk, ov5645->xclk_freq);

set rate can fail, check the error code

> +
> +	ov5645_regulators_get(ov5645);

check for errors.

> +
> +	ret = of_get_named_gpio(dev->of_node, "reset-gpio", 0);

use the right api for gpios devm_gpiod_get here and below.

> +	if (!gpio_is_valid(ret)) {
> +		dev_dbg(dev, "no reset pin available\n");
> +		ov5645->rst_gpio = 0;
> +	} else {
> +		ov5645->rst_gpio = ret;
> +	}
> +
> +	if (ov5645->rst_gpio) {
> +		ret = devm_gpio_request_one(dev, ov5645->rst_gpio,
> +			GPIOF_OUT_INIT_LOW, "ov5645-reset");
> +		if (ret < 0) {
> +			dev_err(dev, "could not request reset gpio\n");
> +			return ret;
> +		}
> +	}

regards,
Stan