media: Add a driver for the ov7251 camera sensor
authorTodor Tomov <todor.tomov@linaro.org>
Wed, 25 Apr 2018 16:20:46 +0000 (12:20 -0400)
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Thu, 17 May 2018 10:22:08 +0000 (06:22 -0400)
The ov7251 sensor is a 1/7.5-Inch B&W VGA (640x480) CMOS Digital Image
Sensor from Omnivision.

The driver supports the following modes:
- 640x480 30fps
- 640x480 60fps
- 640x480 90fps

Output format is 10bit B&W RAW - MEDIA_BUS_FMT_Y10_1X10.

The driver supports configuration via user controls for:
- exposure and gain;
- horizontal and vertical flip;
- test pattern.

[Sakari Ailus: Wrap a line over 80 characters, fix trivial sparse warning]

Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
drivers/media/i2c/Kconfig
drivers/media/i2c/Makefile
drivers/media/i2c/ov7251.c [new file with mode: 0644]

index faaaceb..b95b447 100644 (file)
@@ -688,6 +688,18 @@ config VIDEO_OV5695
          To compile this driver as a module, choose M here: the
          module will be called ov5695.
 
+config VIDEO_OV7251
+       tristate "OmniVision OV7251 sensor support"
+       depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+       depends on MEDIA_CAMERA_SUPPORT
+       select V4L2_FWNODE
+       help
+         This is a Video4Linux2 sensor-level driver for the OmniVision
+         OV7251 camera.
+
+         To compile this driver as a module, choose M here: the
+         module will be called ov7251.
+
 config VIDEO_OV772X
        tristate "OmniVision OV772x sensor support"
        depends on I2C && VIDEO_V4L2
index 84cc472..ff6e291 100644 (file)
@@ -70,6 +70,7 @@ obj-$(CONFIG_VIDEO_OV5647) += ov5647.o
 obj-$(CONFIG_VIDEO_OV5670) += ov5670.o
 obj-$(CONFIG_VIDEO_OV5695) += ov5695.o
 obj-$(CONFIG_VIDEO_OV6650) += ov6650.o
+obj-$(CONFIG_VIDEO_OV7251) += ov7251.o
 obj-$(CONFIG_VIDEO_OV7640) += ov7640.o
 obj-$(CONFIG_VIDEO_OV7670) += ov7670.o
 obj-$(CONFIG_VIDEO_OV772X) += ov772x.o
diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
new file mode 100644 (file)
index 0000000..d3ebb75
--- /dev/null
@@ -0,0 +1,1503 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the OV7251 camera sensor.
+ *
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018, Linaro Ltd.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+#define OV7251_SC_MODE_SELECT          0x0100
+#define OV7251_SC_MODE_SELECT_SW_STANDBY       0x0
+#define OV7251_SC_MODE_SELECT_STREAMING                0x1
+
+#define OV7251_CHIP_ID_HIGH            0x300a
+#define OV7251_CHIP_ID_HIGH_BYTE       0x77
+#define OV7251_CHIP_ID_LOW             0x300b
+#define OV7251_CHIP_ID_LOW_BYTE                0x50
+#define OV7251_SC_GP_IO_IN1            0x3029
+#define OV7251_AEC_EXPO_0              0x3500
+#define OV7251_AEC_EXPO_1              0x3501
+#define OV7251_AEC_EXPO_2              0x3502
+#define OV7251_AEC_AGC_ADJ_0           0x350a
+#define OV7251_AEC_AGC_ADJ_1           0x350b
+#define OV7251_TIMING_FORMAT1          0x3820
+#define OV7251_TIMING_FORMAT1_VFLIP    BIT(2)
+#define OV7251_TIMING_FORMAT2          0x3821
+#define OV7251_TIMING_FORMAT2_MIRROR   BIT(2)
+#define OV7251_PRE_ISP_00              0x5e00
+#define OV7251_PRE_ISP_00_TEST_PATTERN BIT(7)
+
+struct reg_value {
+       u16 reg;
+       u8 val;
+};
+
+struct ov7251_mode_info {
+       u32 width;
+       u32 height;
+       const struct reg_value *data;
+       u32 data_size;
+       u32 pixel_clock;
+       u32 link_freq;
+       u16 exposure_max;
+       u16 exposure_def;
+       struct v4l2_fract timeperframe;
+};
+
+struct ov7251 {
+       struct i2c_client *i2c_client;
+       struct device *dev;
+       struct v4l2_subdev sd;
+       struct media_pad pad;
+       struct v4l2_fwnode_endpoint ep;
+       struct v4l2_mbus_framefmt fmt;
+       struct v4l2_rect crop;
+       struct clk *xclk;
+       u32 xclk_freq;
+
+       struct regulator *io_regulator;
+       struct regulator *core_regulator;
+       struct regulator *analog_regulator;
+
+       const struct ov7251_mode_info *current_mode;
+
+       struct v4l2_ctrl_handler ctrls;
+       struct v4l2_ctrl *pixel_clock;
+       struct v4l2_ctrl *link_freq;
+       struct v4l2_ctrl *exposure;
+       struct v4l2_ctrl *gain;
+
+       /* Cached register values */
+       u8 aec_pk_manual;
+       u8 pre_isp_00;
+       u8 timing_format1;
+       u8 timing_format2;
+
+       struct mutex lock; /* lock to protect power state, ctrls and mode */
+       bool power_on;
+
+       struct gpio_desc *enable_gpio;
+};
+
+static inline struct ov7251 *to_ov7251(struct v4l2_subdev *sd)
+{
+       return container_of(sd, struct ov7251, sd);
+}
+
+static const struct reg_value ov7251_global_init_setting[] = {
+       { 0x0103, 0x01 },
+       { 0x303b, 0x02 },
+};
+
+static const struct reg_value ov7251_setting_vga_30fps[] = {
+       { 0x3005, 0x00 },
+       { 0x3012, 0xc0 },
+       { 0x3013, 0xd2 },
+       { 0x3014, 0x04 },
+       { 0x3016, 0xf0 },
+       { 0x3017, 0xf0 },
+       { 0x3018, 0xf0 },
+       { 0x301a, 0xf0 },
+       { 0x301b, 0xf0 },
+       { 0x301c, 0xf0 },
+       { 0x3023, 0x05 },
+       { 0x3037, 0xf0 },
+       { 0x3098, 0x04 }, /* pll2 pre divider */
+       { 0x3099, 0x28 }, /* pll2 multiplier */
+       { 0x309a, 0x05 }, /* pll2 sys divider */
+       { 0x309b, 0x04 }, /* pll2 adc divider */
+       { 0x309d, 0x00 }, /* pll2 divider */
+       { 0x30b0, 0x0a }, /* pll1 pix divider */
+       { 0x30b1, 0x01 }, /* pll1 divider */
+       { 0x30b3, 0x64 }, /* pll1 multiplier */
+       { 0x30b4, 0x03 }, /* pll1 pre divider */
+       { 0x30b5, 0x05 }, /* pll1 mipi divider */
+       { 0x3106, 0xda },
+       { 0x3503, 0x07 },
+       { 0x3509, 0x10 },
+       { 0x3600, 0x1c },
+       { 0x3602, 0x62 },
+       { 0x3620, 0xb7 },
+       { 0x3622, 0x04 },
+       { 0x3626, 0x21 },
+       { 0x3627, 0x30 },
+       { 0x3630, 0x44 },
+       { 0x3631, 0x35 },
+       { 0x3634, 0x60 },
+       { 0x3636, 0x00 },
+       { 0x3662, 0x01 },
+       { 0x3663, 0x70 },
+       { 0x3664, 0x50 },
+       { 0x3666, 0x0a },
+       { 0x3669, 0x1a },
+       { 0x366a, 0x00 },
+       { 0x366b, 0x50 },
+       { 0x3673, 0x01 },
+       { 0x3674, 0xff },
+       { 0x3675, 0x03 },
+       { 0x3705, 0xc1 },
+       { 0x3709, 0x40 },
+       { 0x373c, 0x08 },
+       { 0x3742, 0x00 },
+       { 0x3757, 0xb3 },
+       { 0x3788, 0x00 },
+       { 0x37a8, 0x01 },
+       { 0x37a9, 0xc0 },
+       { 0x3800, 0x00 },
+       { 0x3801, 0x04 },
+       { 0x3802, 0x00 },
+       { 0x3803, 0x04 },
+       { 0x3804, 0x02 },
+       { 0x3805, 0x8b },
+       { 0x3806, 0x01 },
+       { 0x3807, 0xeb },
+       { 0x3808, 0x02 }, /* width high */
+       { 0x3809, 0x80 }, /* width low */
+       { 0x380a, 0x01 }, /* height high */
+       { 0x380b, 0xe0 }, /* height low */
+       { 0x380c, 0x03 }, /* total horiz timing high */
+       { 0x380d, 0xa0 }, /* total horiz timing low */
+       { 0x380e, 0x06 }, /* total vertical timing high */
+       { 0x380f, 0xbc }, /* total vertical timing low */
+       { 0x3810, 0x00 },
+       { 0x3811, 0x04 },
+       { 0x3812, 0x00 },
+       { 0x3813, 0x05 },
+       { 0x3814, 0x11 },
+       { 0x3815, 0x11 },
+       { 0x3820, 0x40 },
+       { 0x3821, 0x00 },
+       { 0x382f, 0x0e },
+       { 0x3832, 0x00 },
+       { 0x3833, 0x05 },
+       { 0x3834, 0x00 },
+       { 0x3835, 0x0c },
+       { 0x3837, 0x00 },
+       { 0x3b80, 0x00 },
+       { 0x3b81, 0xa5 },
+       { 0x3b82, 0x10 },
+       { 0x3b83, 0x00 },
+       { 0x3b84, 0x08 },
+       { 0x3b85, 0x00 },
+       { 0x3b86, 0x01 },
+       { 0x3b87, 0x00 },
+       { 0x3b88, 0x00 },
+       { 0x3b89, 0x00 },
+       { 0x3b8a, 0x00 },
+       { 0x3b8b, 0x05 },
+       { 0x3b8c, 0x00 },
+       { 0x3b8d, 0x00 },
+       { 0x3b8e, 0x00 },
+       { 0x3b8f, 0x1a },
+       { 0x3b94, 0x05 },
+       { 0x3b95, 0xf2 },
+       { 0x3b96, 0x40 },
+       { 0x3c00, 0x89 },
+       { 0x3c01, 0x63 },
+       { 0x3c02, 0x01 },
+       { 0x3c03, 0x00 },
+       { 0x3c04, 0x00 },
+       { 0x3c05, 0x03 },
+       { 0x3c06, 0x00 },
+       { 0x3c07, 0x06 },
+       { 0x3c0c, 0x01 },
+       { 0x3c0d, 0xd0 },
+       { 0x3c0e, 0x02 },
+       { 0x3c0f, 0x0a },
+       { 0x4001, 0x42 },
+       { 0x4004, 0x04 },
+       { 0x4005, 0x00 },
+       { 0x404e, 0x01 },
+       { 0x4300, 0xff },
+       { 0x4301, 0x00 },
+       { 0x4315, 0x00 },
+       { 0x4501, 0x48 },
+       { 0x4600, 0x00 },
+       { 0x4601, 0x4e },
+       { 0x4801, 0x0f },
+       { 0x4806, 0x0f },
+       { 0x4819, 0xaa },
+       { 0x4823, 0x3e },
+       { 0x4837, 0x19 },
+       { 0x4a0d, 0x00 },
+       { 0x4a47, 0x7f },
+       { 0x4a49, 0xf0 },
+       { 0x4a4b, 0x30 },
+       { 0x5000, 0x85 },
+       { 0x5001, 0x80 },
+};
+
+static const struct reg_value ov7251_setting_vga_60fps[] = {
+       { 0x3005, 0x00 },
+       { 0x3012, 0xc0 },
+       { 0x3013, 0xd2 },
+       { 0x3014, 0x04 },
+       { 0x3016, 0x10 },
+       { 0x3017, 0x00 },
+       { 0x3018, 0x00 },
+       { 0x301a, 0x00 },
+       { 0x301b, 0x00 },
+       { 0x301c, 0x00 },
+       { 0x3023, 0x05 },
+       { 0x3037, 0xf0 },
+       { 0x3098, 0x04 }, /* pll2 pre divider */
+       { 0x3099, 0x28 }, /* pll2 multiplier */
+       { 0x309a, 0x05 }, /* pll2 sys divider */
+       { 0x309b, 0x04 }, /* pll2 adc divider */
+       { 0x309d, 0x00 }, /* pll2 divider */
+       { 0x30b0, 0x0a }, /* pll1 pix divider */
+       { 0x30b1, 0x01 }, /* pll1 divider */
+       { 0x30b3, 0x64 }, /* pll1 multiplier */
+       { 0x30b4, 0x03 }, /* pll1 pre divider */
+       { 0x30b5, 0x05 }, /* pll1 mipi divider */
+       { 0x3106, 0xda },
+       { 0x3503, 0x07 },
+       { 0x3509, 0x10 },
+       { 0x3600, 0x1c },
+       { 0x3602, 0x62 },
+       { 0x3620, 0xb7 },
+       { 0x3622, 0x04 },
+       { 0x3626, 0x21 },
+       { 0x3627, 0x30 },
+       { 0x3630, 0x44 },
+       { 0x3631, 0x35 },
+       { 0x3634, 0x60 },
+       { 0x3636, 0x00 },
+       { 0x3662, 0x01 },
+       { 0x3663, 0x70 },
+       { 0x3664, 0x50 },
+       { 0x3666, 0x0a },
+       { 0x3669, 0x1a },
+       { 0x366a, 0x00 },
+       { 0x366b, 0x50 },
+       { 0x3673, 0x01 },
+       { 0x3674, 0xff },
+       { 0x3675, 0x03 },
+       { 0x3705, 0xc1 },
+       { 0x3709, 0x40 },
+       { 0x373c, 0x08 },
+       { 0x3742, 0x00 },
+       { 0x3757, 0xb3 },
+       { 0x3788, 0x00 },
+       { 0x37a8, 0x01 },
+       { 0x37a9, 0xc0 },
+       { 0x3800, 0x00 },
+       { 0x3801, 0x04 },
+       { 0x3802, 0x00 },
+       { 0x3803, 0x04 },
+       { 0x3804, 0x02 },
+       { 0x3805, 0x8b },
+       { 0x3806, 0x01 },
+       { 0x3807, 0xeb },
+       { 0x3808, 0x02 }, /* width high */
+       { 0x3809, 0x80 }, /* width low */
+       { 0x380a, 0x01 }, /* height high */
+       { 0x380b, 0xe0 }, /* height low */
+       { 0x380c, 0x03 }, /* total horiz timing high */
+       { 0x380d, 0xa0 }, /* total horiz timing low */
+       { 0x380e, 0x03 }, /* total vertical timing high */
+       { 0x380f, 0x5c }, /* total vertical timing low */
+       { 0x3810, 0x00 },
+       { 0x3811, 0x04 },
+       { 0x3812, 0x00 },
+       { 0x3813, 0x05 },
+       { 0x3814, 0x11 },
+       { 0x3815, 0x11 },
+       { 0x3820, 0x40 },
+       { 0x3821, 0x00 },
+       { 0x382f, 0x0e },
+       { 0x3832, 0x00 },
+       { 0x3833, 0x05 },
+       { 0x3834, 0x00 },
+       { 0x3835, 0x0c },
+       { 0x3837, 0x00 },
+       { 0x3b80, 0x00 },
+       { 0x3b81, 0xa5 },
+       { 0x3b82, 0x10 },
+       { 0x3b83, 0x00 },
+       { 0x3b84, 0x08 },
+       { 0x3b85, 0x00 },
+       { 0x3b86, 0x01 },
+       { 0x3b87, 0x00 },
+       { 0x3b88, 0x00 },
+       { 0x3b89, 0x00 },
+       { 0x3b8a, 0x00 },
+       { 0x3b8b, 0x05 },
+       { 0x3b8c, 0x00 },
+       { 0x3b8d, 0x00 },
+       { 0x3b8e, 0x00 },
+       { 0x3b8f, 0x1a },
+       { 0x3b94, 0x05 },
+       { 0x3b95, 0xf2 },
+       { 0x3b96, 0x40 },
+       { 0x3c00, 0x89 },
+       { 0x3c01, 0x63 },
+       { 0x3c02, 0x01 },
+       { 0x3c03, 0x00 },
+       { 0x3c04, 0x00 },
+       { 0x3c05, 0x03 },
+       { 0x3c06, 0x00 },
+       { 0x3c07, 0x06 },
+       { 0x3c0c, 0x01 },
+       { 0x3c0d, 0xd0 },
+       { 0x3c0e, 0x02 },
+       { 0x3c0f, 0x0a },
+       { 0x4001, 0x42 },
+       { 0x4004, 0x04 },
+       { 0x4005, 0x00 },
+       { 0x404e, 0x01 },
+       { 0x4300, 0xff },
+       { 0x4301, 0x00 },
+       { 0x4315, 0x00 },
+       { 0x4501, 0x48 },
+       { 0x4600, 0x00 },
+       { 0x4601, 0x4e },
+       { 0x4801, 0x0f },
+       { 0x4806, 0x0f },
+       { 0x4819, 0xaa },
+       { 0x4823, 0x3e },
+       { 0x4837, 0x19 },
+       { 0x4a0d, 0x00 },
+       { 0x4a47, 0x7f },
+       { 0x4a49, 0xf0 },
+       { 0x4a4b, 0x30 },
+       { 0x5000, 0x85 },
+       { 0x5001, 0x80 },
+};
+
+static const struct reg_value ov7251_setting_vga_90fps[] = {
+       { 0x3005, 0x00 },
+       { 0x3012, 0xc0 },
+       { 0x3013, 0xd2 },
+       { 0x3014, 0x04 },
+       { 0x3016, 0x10 },
+       { 0x3017, 0x00 },
+       { 0x3018, 0x00 },
+       { 0x301a, 0x00 },
+       { 0x301b, 0x00 },
+       { 0x301c, 0x00 },
+       { 0x3023, 0x05 },
+       { 0x3037, 0xf0 },
+       { 0x3098, 0x04 }, /* pll2 pre divider */
+       { 0x3099, 0x28 }, /* pll2 multiplier */
+       { 0x309a, 0x05 }, /* pll2 sys divider */
+       { 0x309b, 0x04 }, /* pll2 adc divider */
+       { 0x309d, 0x00 }, /* pll2 divider */
+       { 0x30b0, 0x0a }, /* pll1 pix divider */
+       { 0x30b1, 0x01 }, /* pll1 divider */
+       { 0x30b3, 0x64 }, /* pll1 multiplier */
+       { 0x30b4, 0x03 }, /* pll1 pre divider */
+       { 0x30b5, 0x05 }, /* pll1 mipi divider */
+       { 0x3106, 0xda },
+       { 0x3503, 0x07 },
+       { 0x3509, 0x10 },
+       { 0x3600, 0x1c },
+       { 0x3602, 0x62 },
+       { 0x3620, 0xb7 },
+       { 0x3622, 0x04 },
+       { 0x3626, 0x21 },
+       { 0x3627, 0x30 },
+       { 0x3630, 0x44 },
+       { 0x3631, 0x35 },
+       { 0x3634, 0x60 },
+       { 0x3636, 0x00 },
+       { 0x3662, 0x01 },
+       { 0x3663, 0x70 },
+       { 0x3664, 0x50 },
+       { 0x3666, 0x0a },
+       { 0x3669, 0x1a },
+       { 0x366a, 0x00 },
+       { 0x366b, 0x50 },
+       { 0x3673, 0x01 },
+       { 0x3674, 0xff },
+       { 0x3675, 0x03 },
+       { 0x3705, 0xc1 },
+       { 0x3709, 0x40 },
+       { 0x373c, 0x08 },
+       { 0x3742, 0x00 },
+       { 0x3757, 0xb3 },
+       { 0x3788, 0x00 },
+       { 0x37a8, 0x01 },
+       { 0x37a9, 0xc0 },
+       { 0x3800, 0x00 },
+       { 0x3801, 0x04 },
+       { 0x3802, 0x00 },
+       { 0x3803, 0x04 },
+       { 0x3804, 0x02 },
+       { 0x3805, 0x8b },
+       { 0x3806, 0x01 },
+       { 0x3807, 0xeb },
+       { 0x3808, 0x02 }, /* width high */
+       { 0x3809, 0x80 }, /* width low */
+       { 0x380a, 0x01 }, /* height high */
+       { 0x380b, 0xe0 }, /* height low */
+       { 0x380c, 0x03 }, /* total horiz timing high */
+       { 0x380d, 0xa0 }, /* total horiz timing low */
+       { 0x380e, 0x02 }, /* total vertical timing high */
+       { 0x380f, 0x3c }, /* total vertical timing low */
+       { 0x3810, 0x00 },
+       { 0x3811, 0x04 },
+       { 0x3812, 0x00 },
+       { 0x3813, 0x05 },
+       { 0x3814, 0x11 },
+       { 0x3815, 0x11 },
+       { 0x3820, 0x40 },
+       { 0x3821, 0x00 },
+       { 0x382f, 0x0e },
+       { 0x3832, 0x00 },
+       { 0x3833, 0x05 },
+       { 0x3834, 0x00 },
+       { 0x3835, 0x0c },
+       { 0x3837, 0x00 },
+       { 0x3b80, 0x00 },
+       { 0x3b81, 0xa5 },
+       { 0x3b82, 0x10 },
+       { 0x3b83, 0x00 },
+       { 0x3b84, 0x08 },
+       { 0x3b85, 0x00 },
+       { 0x3b86, 0x01 },
+       { 0x3b87, 0x00 },
+       { 0x3b88, 0x00 },
+       { 0x3b89, 0x00 },
+       { 0x3b8a, 0x00 },
+       { 0x3b8b, 0x05 },
+       { 0x3b8c, 0x00 },
+       { 0x3b8d, 0x00 },
+       { 0x3b8e, 0x00 },
+       { 0x3b8f, 0x1a },
+       { 0x3b94, 0x05 },
+       { 0x3b95, 0xf2 },
+       { 0x3b96, 0x40 },
+       { 0x3c00, 0x89 },
+       { 0x3c01, 0x63 },
+       { 0x3c02, 0x01 },
+       { 0x3c03, 0x00 },
+       { 0x3c04, 0x00 },
+       { 0x3c05, 0x03 },
+       { 0x3c06, 0x00 },
+       { 0x3c07, 0x06 },
+       { 0x3c0c, 0x01 },
+       { 0x3c0d, 0xd0 },
+       { 0x3c0e, 0x02 },
+       { 0x3c0f, 0x0a },
+       { 0x4001, 0x42 },
+       { 0x4004, 0x04 },
+       { 0x4005, 0x00 },
+       { 0x404e, 0x01 },
+       { 0x4300, 0xff },
+       { 0x4301, 0x00 },
+       { 0x4315, 0x00 },
+       { 0x4501, 0x48 },
+       { 0x4600, 0x00 },
+       { 0x4601, 0x4e },
+       { 0x4801, 0x0f },
+       { 0x4806, 0x0f },
+       { 0x4819, 0xaa },
+       { 0x4823, 0x3e },
+       { 0x4837, 0x19 },
+       { 0x4a0d, 0x00 },
+       { 0x4a47, 0x7f },
+       { 0x4a49, 0xf0 },
+       { 0x4a4b, 0x30 },
+       { 0x5000, 0x85 },
+       { 0x5001, 0x80 },
+};
+
+static const s64 link_freq[] = {
+       240000000,
+};
+
+static const struct ov7251_mode_info ov7251_mode_info_data[] = {
+       {
+               .width = 640,
+               .height = 480,
+               .data = ov7251_setting_vga_30fps,
+               .data_size = ARRAY_SIZE(ov7251_setting_vga_30fps),
+               .pixel_clock = 48000000,
+               .link_freq = 0, /* an index in link_freq[] */
+               .exposure_max = 1704,
+               .exposure_def = 504,
+               .timeperframe = {
+                       .numerator = 100,
+                       .denominator = 3000
+               }
+       },
+       {
+               .width = 640,
+               .height = 480,
+               .data = ov7251_setting_vga_60fps,
+               .data_size = ARRAY_SIZE(ov7251_setting_vga_60fps),
+               .pixel_clock = 48000000,
+               .link_freq = 0, /* an index in link_freq[] */
+               .exposure_max = 840,
+               .exposure_def = 504,
+               .timeperframe = {
+                       .numerator = 100,
+                       .denominator = 6014
+               }
+       },
+       {
+               .width = 640,
+               .height = 480,
+               .data = ov7251_setting_vga_90fps,
+               .data_size = ARRAY_SIZE(ov7251_setting_vga_90fps),
+               .pixel_clock = 48000000,
+               .link_freq = 0, /* an index in link_freq[] */
+               .exposure_max = 552,
+               .exposure_def = 504,
+               .timeperframe = {
+                       .numerator = 100,
+                       .denominator = 9043
+               }
+       },
+};
+
+static int ov7251_regulators_enable(struct ov7251 *ov7251)
+{
+       int ret;
+
+       /* OV7251 power up sequence requires core regulator
+        * to be enabled not earlier than io regulator
+        */
+
+       ret = regulator_enable(ov7251->io_regulator);
+       if (ret < 0) {
+               dev_err(ov7251->dev, "set io voltage failed\n");
+               return ret;
+       }
+
+       ret = regulator_enable(ov7251->analog_regulator);
+       if (ret) {
+               dev_err(ov7251->dev, "set analog voltage failed\n");
+               goto err_disable_io;
+       }
+
+       ret = regulator_enable(ov7251->core_regulator);
+       if (ret) {
+               dev_err(ov7251->dev, "set core voltage failed\n");
+               goto err_disable_analog;
+       }
+
+       return 0;
+
+err_disable_analog:
+       regulator_disable(ov7251->analog_regulator);
+
+err_disable_io:
+       regulator_disable(ov7251->io_regulator);
+
+       return ret;
+}
+
+static void ov7251_regulators_disable(struct ov7251 *ov7251)
+{
+       int ret;
+
+       ret = regulator_disable(ov7251->core_regulator);
+       if (ret < 0)
+               dev_err(ov7251->dev, "core regulator disable failed\n");
+
+       ret = regulator_disable(ov7251->analog_regulator);
+       if (ret < 0)
+               dev_err(ov7251->dev, "analog regulator disable failed\n");
+
+       ret = regulator_disable(ov7251->io_regulator);
+       if (ret < 0)
+               dev_err(ov7251->dev, "io regulator disable failed\n");
+}
+
+static int ov7251_write_reg(struct ov7251 *ov7251, u16 reg, u8 val)
+{
+       u8 regbuf[3];
+       int ret;
+
+       regbuf[0] = reg >> 8;
+       regbuf[1] = reg & 0xff;
+       regbuf[2] = val;
+
+       ret = i2c_master_send(ov7251->i2c_client, regbuf, 3);
+       if (ret < 0) {
+               dev_err(ov7251->dev, "%s: write reg error %d: reg=%x, val=%x\n",
+                       __func__, ret, reg, val);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int ov7251_write_seq_regs(struct ov7251 *ov7251, u16 reg, u8 *val,
+                                u8 num)
+{
+       u8 regbuf[5];
+       u8 nregbuf = sizeof(reg) + num * sizeof(*val);
+       int ret = 0;
+
+       if (nregbuf > sizeof(regbuf))
+               return -EINVAL;
+
+       regbuf[0] = reg >> 8;
+       regbuf[1] = reg & 0xff;
+
+       memcpy(regbuf + 2, val, num);
+
+       ret = i2c_master_send(ov7251->i2c_client, regbuf, nregbuf);
+       if (ret < 0) {
+               dev_err(ov7251->dev,
+                       "%s: write seq regs error %d: first reg=%x\n",
+                       __func__, ret, reg);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int ov7251_read_reg(struct ov7251 *ov7251, u16 reg, u8 *val)
+{
+       u8 regbuf[2];
+       int ret;
+
+       regbuf[0] = reg >> 8;
+       regbuf[1] = reg & 0xff;
+
+       ret = i2c_master_send(ov7251->i2c_client, regbuf, 2);
+       if (ret < 0) {
+               dev_err(ov7251->dev, "%s: write reg error %d: reg=%x\n",
+                       __func__, ret, reg);
+               return ret;
+       }
+
+       ret = i2c_master_recv(ov7251->i2c_client, val, 1);
+       if (ret < 0) {
+               dev_err(ov7251->dev, "%s: read reg error %d: reg=%x\n",
+                       __func__, ret, reg);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int ov7251_set_exposure(struct ov7251 *ov7251, s32 exposure)
+{
+       u16 reg;
+       u8 val[3];
+
+       reg = OV7251_AEC_EXPO_0;
+       val[0] = (exposure & 0xf000) >> 12; /* goes to OV7251_AEC_EXPO_0 */
+       val[1] = (exposure & 0x0ff0) >> 4;  /* goes to OV7251_AEC_EXPO_1 */
+       val[2] = (exposure & 0x000f) << 4;  /* goes to OV7251_AEC_EXPO_2 */
+
+       return ov7251_write_seq_regs(ov7251, reg, val, 3);
+}
+
+static int ov7251_set_gain(struct ov7251 *ov7251, s32 gain)
+{
+       u16 reg;
+       u8 val[2];
+
+       reg = OV7251_AEC_AGC_ADJ_0;
+       val[0] = (gain & 0x0300) >> 8; /* goes to OV7251_AEC_AGC_ADJ_0 */
+       val[1] = gain & 0xff;          /* goes to OV7251_AEC_AGC_ADJ_1 */
+
+       return ov7251_write_seq_regs(ov7251, reg, val, 2);
+}
+
+static int ov7251_set_register_array(struct ov7251 *ov7251,
+                                    const struct reg_value *settings,
+                                    unsigned int num_settings)
+{
+       unsigned int i;
+       int ret;
+
+       for (i = 0; i < num_settings; ++i, ++settings) {
+               ret = ov7251_write_reg(ov7251, settings->reg, settings->val);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
+static int ov7251_set_power_on(struct ov7251 *ov7251)
+{
+       int ret;
+       u32 wait_us;
+
+       ret = ov7251_regulators_enable(ov7251);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_prepare_enable(ov7251->xclk);
+       if (ret < 0) {
+               dev_err(ov7251->dev, "clk prepare enable failed\n");
+               ov7251_regulators_disable(ov7251);
+               return ret;
+       }
+
+       gpiod_set_value_cansleep(ov7251->enable_gpio, 1);
+
+       /* wait at least 65536 external clock cycles */
+       wait_us = DIV_ROUND_UP(65536 * 1000,
+                              DIV_ROUND_UP(ov7251->xclk_freq, 1000));
+       usleep_range(wait_us, wait_us + 1000);
+
+       return 0;
+}
+
+static void ov7251_set_power_off(struct ov7251 *ov7251)
+{
+       clk_disable_unprepare(ov7251->xclk);
+       gpiod_set_value_cansleep(ov7251->enable_gpio, 0);
+       ov7251_regulators_disable(ov7251);
+}
+
+static int ov7251_s_power(struct v4l2_subdev *sd, int on)
+{
+       struct ov7251 *ov7251 = to_ov7251(sd);
+       int ret = 0;
+
+       mutex_lock(&ov7251->lock);
+
+       /* If the power state is not modified - no work to do. */
+       if (ov7251->power_on == !!on)
+               goto exit;
+
+       if (on) {
+               ret = ov7251_set_power_on(ov7251);
+               if (ret < 0)
+                       goto exit;
+
+               ret = ov7251_set_register_array(ov7251,
+                                       ov7251_global_init_setting,
+                                       ARRAY_SIZE(ov7251_global_init_setting));
+               if (ret < 0) {
+                       dev_err(ov7251->dev, "could not set init registers\n");
+                       ov7251_set_power_off(ov7251);
+                       goto exit;
+               }
+
+               ov7251->power_on = true;
+       } else {
+               ov7251_set_power_off(ov7251);
+               ov7251->power_on = false;
+       }
+
+exit:
+       mutex_unlock(&ov7251->lock);
+
+       return ret;
+}
+
+static int ov7251_set_hflip(struct ov7251 *ov7251, s32 value)
+{
+       u8 val = ov7251->timing_format2;
+       int ret;
+
+       if (value)
+               val |= OV7251_TIMING_FORMAT2_MIRROR;
+       else
+               val &= ~OV7251_TIMING_FORMAT2_MIRROR;
+
+       ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT2, val);
+       if (!ret)
+               ov7251->timing_format2 = val;
+
+       return ret;
+}
+
+static int ov7251_set_vflip(struct ov7251 *ov7251, s32 value)
+{
+       u8 val = ov7251->timing_format1;
+       int ret;
+
+       if (value)
+               val |= OV7251_TIMING_FORMAT1_VFLIP;
+       else
+               val &= ~OV7251_TIMING_FORMAT1_VFLIP;
+
+       ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT1, val);
+       if (!ret)
+               ov7251->timing_format1 = val;
+
+       return ret;
+}
+
+static int ov7251_set_test_pattern(struct ov7251 *ov7251, s32 value)
+{
+       u8 val = ov7251->pre_isp_00;
+       int ret;
+
+       if (value)
+               val |= OV7251_PRE_ISP_00_TEST_PATTERN;
+       else
+               val &= ~OV7251_PRE_ISP_00_TEST_PATTERN;
+
+       ret = ov7251_write_reg(ov7251, OV7251_PRE_ISP_00, val);
+       if (!ret)
+               ov7251->pre_isp_00 = val;
+
+       return ret;
+}
+
+static const char * const ov7251_test_pattern_menu[] = {
+       "Disabled",
+       "Vertical Pattern Bars",
+};
+
+static int ov7251_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+       struct ov7251 *ov7251 = container_of(ctrl->handler,
+                                            struct ov7251, ctrls);
+       int ret;
+
+       /* v4l2_ctrl_lock() locks our mutex */
+
+       if (!ov7251->power_on)
+               return 0;
+
+       switch (ctrl->id) {
+       case V4L2_CID_EXPOSURE:
+               ret = ov7251_set_exposure(ov7251, ctrl->val);
+               break;
+       case V4L2_CID_GAIN:
+               ret = ov7251_set_gain(ov7251, ctrl->val);
+               break;
+       case V4L2_CID_TEST_PATTERN:
+               ret = ov7251_set_test_pattern(ov7251, ctrl->val);
+               break;
+       case V4L2_CID_HFLIP:
+               ret = ov7251_set_hflip(ov7251, ctrl->val);
+               break;
+       case V4L2_CID_VFLIP:
+               ret = ov7251_set_vflip(ov7251, ctrl->val);
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static const struct v4l2_ctrl_ops ov7251_ctrl_ops = {
+       .s_ctrl = ov7251_s_ctrl,
+};
+
+static int ov7251_enum_mbus_code(struct v4l2_subdev *sd,
+                                struct v4l2_subdev_pad_config *cfg,
+                                struct v4l2_subdev_mbus_code_enum *code)
+{
+       if (code->index > 0)
+               return -EINVAL;
+
+       code->code = MEDIA_BUS_FMT_Y10_1X10;
+
+       return 0;
+}
+
+static int ov7251_enum_frame_size(struct v4l2_subdev *subdev,
+                                 struct v4l2_subdev_pad_config *cfg,
+                                 struct v4l2_subdev_frame_size_enum *fse)
+{
+       if (fse->code != MEDIA_BUS_FMT_Y10_1X10)
+               return -EINVAL;
+
+       if (fse->index >= ARRAY_SIZE(ov7251_mode_info_data))
+               return -EINVAL;
+
+       fse->min_width = ov7251_mode_info_data[fse->index].width;
+       fse->max_width = ov7251_mode_info_data[fse->index].width;
+       fse->min_height = ov7251_mode_info_data[fse->index].height;
+       fse->max_height = ov7251_mode_info_data[fse->index].height;
+
+       return 0;
+}
+
+static int ov7251_enum_frame_ival(struct v4l2_subdev *subdev,
+                                 struct v4l2_subdev_pad_config *cfg,
+                                 struct v4l2_subdev_frame_interval_enum *fie)
+{
+       unsigned int index = fie->index;
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
+               if (fie->width != ov7251_mode_info_data[i].width ||
+                   fie->height != ov7251_mode_info_data[i].height)
+                       continue;
+
+               if (index-- == 0) {
+                       fie->interval = ov7251_mode_info_data[i].timeperframe;
+                       return 0;
+               }
+       }
+
+       return -EINVAL;
+}
+
+static struct v4l2_mbus_framefmt *
+__ov7251_get_pad_format(struct ov7251 *ov7251,
+                       struct v4l2_subdev_pad_config *cfg,
+                       unsigned int pad,
+                       enum v4l2_subdev_format_whence which)
+{
+       switch (which) {
+       case V4L2_SUBDEV_FORMAT_TRY:
+               return v4l2_subdev_get_try_format(&ov7251->sd, cfg, pad);
+       case V4L2_SUBDEV_FORMAT_ACTIVE:
+               return &ov7251->fmt;
+       default:
+               return NULL;
+       }
+}
+
+static int ov7251_get_format(struct v4l2_subdev *sd,
+                            struct v4l2_subdev_pad_config *cfg,
+                            struct v4l2_subdev_format *format)
+{
+       struct ov7251 *ov7251 = to_ov7251(sd);
+
+       mutex_lock(&ov7251->lock);
+       format->format = *__ov7251_get_pad_format(ov7251, cfg, format->pad,
+                                                 format->which);
+       mutex_unlock(&ov7251->lock);
+
+       return 0;
+}
+
+static struct v4l2_rect *
+__ov7251_get_pad_crop(struct ov7251 *ov7251, struct v4l2_subdev_pad_config *cfg,
+                     unsigned int pad, enum v4l2_subdev_format_whence which)
+{
+       switch (which) {
+       case V4L2_SUBDEV_FORMAT_TRY:
+               return v4l2_subdev_get_try_crop(&ov7251->sd, cfg, pad);
+       case V4L2_SUBDEV_FORMAT_ACTIVE:
+               return &ov7251->crop;
+       default:
+               return NULL;
+       }
+}
+
+static inline u32 avg_fps(const struct v4l2_fract *t)
+{
+       return (t->denominator + (t->numerator >> 1)) / t->numerator;
+}
+
+static const struct ov7251_mode_info *
+ov7251_find_mode_by_ival(struct ov7251 *ov7251, struct v4l2_fract *timeperframe)
+{
+       const struct ov7251_mode_info *mode = ov7251->current_mode;
+       unsigned int fps_req = avg_fps(timeperframe);
+       unsigned int max_dist_match = (unsigned int) -1;
+       unsigned int i, n = 0;
+
+       for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
+               unsigned int dist;
+               unsigned int fps_tmp;
+
+               if (mode->width != ov7251_mode_info_data[i].width ||
+                   mode->height != ov7251_mode_info_data[i].height)
+                       continue;
+
+               fps_tmp = avg_fps(&ov7251_mode_info_data[i].timeperframe);
+
+               dist = abs(fps_req - fps_tmp);
+
+               if (dist < max_dist_match) {
+                       n = i;
+                       max_dist_match = dist;
+               }
+       }
+
+       return &ov7251_mode_info_data[n];
+}
+
+static int ov7251_set_format(struct v4l2_subdev *sd,
+                            struct v4l2_subdev_pad_config *cfg,
+                            struct v4l2_subdev_format *format)
+{
+       struct ov7251 *ov7251 = to_ov7251(sd);
+       struct v4l2_mbus_framefmt *__format;
+       struct v4l2_rect *__crop;
+       const struct ov7251_mode_info *new_mode;
+       int ret = 0;
+
+       mutex_lock(&ov7251->lock);
+
+       __crop = __ov7251_get_pad_crop(ov7251, cfg, format->pad, format->which);
+
+       new_mode = v4l2_find_nearest_size(ov7251_mode_info_data,
+                               ARRAY_SIZE(ov7251_mode_info_data),
+                               width, height,
+                               format->format.width, format->format.height);
+
+       __crop->width = new_mode->width;
+       __crop->height = new_mode->height;
+
+       if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
+               ret = __v4l2_ctrl_s_ctrl_int64(ov7251->pixel_clock,
+                                              new_mode->pixel_clock);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->link_freq,
+                                        new_mode->link_freq);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_modify_range(ov7251->exposure,
+                                              1, new_mode->exposure_max,
+                                              1, new_mode->exposure_def);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->exposure,
+                                        new_mode->exposure_def);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->gain, 16);
+               if (ret < 0)
+                       goto exit;
+
+               ov7251->current_mode = new_mode;
+       }
+
+       __format = __ov7251_get_pad_format(ov7251, cfg, format->pad,
+                                          format->which);
+       __format->width = __crop->width;
+       __format->height = __crop->height;
+       __format->code = MEDIA_BUS_FMT_Y10_1X10;
+       __format->field = V4L2_FIELD_NONE;
+       __format->colorspace = V4L2_COLORSPACE_SRGB;
+       __format->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(__format->colorspace);
+       __format->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
+                               __format->colorspace, __format->ycbcr_enc);
+       __format->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(__format->colorspace);
+
+       format->format = *__format;
+
+exit:
+       mutex_unlock(&ov7251->lock);
+
+       return ret;
+}
+
+static int ov7251_entity_init_cfg(struct v4l2_subdev *subdev,
+                                 struct v4l2_subdev_pad_config *cfg)
+{
+       struct v4l2_subdev_format fmt = {
+               .which = cfg ? V4L2_SUBDEV_FORMAT_TRY
+                            : V4L2_SUBDEV_FORMAT_ACTIVE,
+               .format = {
+                       .width = 640,
+                       .height = 480
+               }
+       };
+
+       ov7251_set_format(subdev, cfg, &fmt);
+
+       return 0;
+}
+
+static int ov7251_get_selection(struct v4l2_subdev *sd,
+                               struct v4l2_subdev_pad_config *cfg,
+                               struct v4l2_subdev_selection *sel)
+{
+       struct ov7251 *ov7251 = to_ov7251(sd);
+
+       if (sel->target != V4L2_SEL_TGT_CROP)
+               return -EINVAL;
+
+       mutex_lock(&ov7251->lock);
+       sel->r = *__ov7251_get_pad_crop(ov7251, cfg, sel->pad,
+                                       sel->which);
+       mutex_unlock(&ov7251->lock);
+
+       return 0;
+}
+
+static int ov7251_s_stream(struct v4l2_subdev *subdev, int enable)
+{
+       struct ov7251 *ov7251 = to_ov7251(subdev);
+       int ret;
+
+       mutex_lock(&ov7251->lock);
+
+       if (enable) {
+               ret = ov7251_set_register_array(ov7251,
+                                       ov7251->current_mode->data,
+                                       ov7251->current_mode->data_size);
+               if (ret < 0) {
+                       dev_err(ov7251->dev, "could not set mode %dx%d\n",
+                               ov7251->current_mode->width,
+                               ov7251->current_mode->height);
+                       goto exit;
+               }
+               ret = __v4l2_ctrl_handler_setup(&ov7251->ctrls);
+               if (ret < 0) {
+                       dev_err(ov7251->dev, "could not sync v4l2 controls\n");
+                       goto exit;
+               }
+               ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
+                                      OV7251_SC_MODE_SELECT_STREAMING);
+       } else {
+               ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
+                                      OV7251_SC_MODE_SELECT_SW_STANDBY);
+       }
+
+exit:
+       mutex_unlock(&ov7251->lock);
+
+       return ret;
+}
+
+static int ov7251_get_frame_interval(struct v4l2_subdev *subdev,
+                                    struct v4l2_subdev_frame_interval *fi)
+{
+       struct ov7251 *ov7251 = to_ov7251(subdev);
+
+       mutex_lock(&ov7251->lock);
+       fi->interval = ov7251->current_mode->timeperframe;
+       mutex_unlock(&ov7251->lock);
+
+       return 0;
+}
+
+static int ov7251_set_frame_interval(struct v4l2_subdev *subdev,
+                                    struct v4l2_subdev_frame_interval *fi)
+{
+       struct ov7251 *ov7251 = to_ov7251(subdev);
+       const struct ov7251_mode_info *new_mode;
+       int ret = 0;
+
+       mutex_lock(&ov7251->lock);
+       new_mode = ov7251_find_mode_by_ival(ov7251, &fi->interval);
+
+       if (new_mode != ov7251->current_mode) {
+               ret = __v4l2_ctrl_s_ctrl_int64(ov7251->pixel_clock,
+                                              new_mode->pixel_clock);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->link_freq,
+                                        new_mode->link_freq);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_modify_range(ov7251->exposure,
+                                              1, new_mode->exposure_max,
+                                              1, new_mode->exposure_def);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->exposure,
+                                        new_mode->exposure_def);
+               if (ret < 0)
+                       goto exit;
+
+               ret = __v4l2_ctrl_s_ctrl(ov7251->gain, 16);
+               if (ret < 0)
+                       goto exit;
+
+               ov7251->current_mode = new_mode;
+       }
+
+       fi->interval = ov7251->current_mode->timeperframe;
+
+exit:
+       mutex_unlock(&ov7251->lock);
+
+       return ret;
+}
+
+static const struct v4l2_subdev_core_ops ov7251_core_ops = {
+       .s_power = ov7251_s_power,
+};
+
+static const struct v4l2_subdev_video_ops ov7251_video_ops = {
+       .s_stream = ov7251_s_stream,
+       .g_frame_interval = ov7251_get_frame_interval,
+       .s_frame_interval = ov7251_set_frame_interval,
+};
+
+static const struct v4l2_subdev_pad_ops ov7251_subdev_pad_ops = {
+       .init_cfg = ov7251_entity_init_cfg,
+       .enum_mbus_code = ov7251_enum_mbus_code,
+       .enum_frame_size = ov7251_enum_frame_size,
+       .enum_frame_interval = ov7251_enum_frame_ival,
+       .get_fmt = ov7251_get_format,
+       .set_fmt = ov7251_set_format,
+       .get_selection = ov7251_get_selection,
+};
+
+static const struct v4l2_subdev_ops ov7251_subdev_ops = {
+       .core = &ov7251_core_ops,
+       .video = &ov7251_video_ops,
+       .pad = &ov7251_subdev_pad_ops,
+};
+
+static int ov7251_probe(struct i2c_client *client)
+{
+       struct device *dev = &client->dev;
+       struct fwnode_handle *endpoint;
+       struct ov7251 *ov7251;
+       u8 chip_id_high, chip_id_low, chip_rev;
+       int ret;
+
+       ov7251 = devm_kzalloc(dev, sizeof(struct ov7251), GFP_KERNEL);
+       if (!ov7251)
+               return -ENOMEM;
+
+       ov7251->i2c_client = client;
+       ov7251->dev = dev;
+
+       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_parse(endpoint, &ov7251->ep);
+       fwnode_handle_put(endpoint);
+       if (ret < 0) {
+               dev_err(dev, "parsing endpoint node failed\n");
+               return ret;
+       }
+
+       if (ov7251->ep.bus_type != V4L2_MBUS_CSI2) {
+               dev_err(dev, "invalid bus type (%u), must be CSI2 (%u)\n",
+                       ov7251->ep.bus_type, V4L2_MBUS_CSI2);
+               return -EINVAL;
+       }
+
+       /* get system clock (xclk) */
+       ov7251->xclk = devm_clk_get(dev, "xclk");
+       if (IS_ERR(ov7251->xclk)) {
+               dev_err(dev, "could not get xclk");
+               return PTR_ERR(ov7251->xclk);
+       }
+
+       ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
+                                      &ov7251->xclk_freq);
+       if (ret) {
+               dev_err(dev, "could not get xclk frequency\n");
+               return ret;
+       }
+
+       /* external clock must be 24MHz, allow 1% tolerance */
+       if (ov7251->xclk_freq < 23760000 || ov7251->xclk_freq > 24240000) {
+               dev_err(dev, "external clock frequency %u is not supported\n",
+                       ov7251->xclk_freq);
+               return -EINVAL;
+       }
+
+       ret = clk_set_rate(ov7251->xclk, ov7251->xclk_freq);
+       if (ret) {
+               dev_err(dev, "could not set xclk frequency\n");
+               return ret;
+       }
+
+       ov7251->io_regulator = devm_regulator_get(dev, "vdddo");
+       if (IS_ERR(ov7251->io_regulator)) {
+               dev_err(dev, "cannot get io regulator\n");
+               return PTR_ERR(ov7251->io_regulator);
+       }
+
+       ov7251->core_regulator = devm_regulator_get(dev, "vddd");
+       if (IS_ERR(ov7251->core_regulator)) {
+               dev_err(dev, "cannot get core regulator\n");
+               return PTR_ERR(ov7251->core_regulator);
+       }
+
+       ov7251->analog_regulator = devm_regulator_get(dev, "vdda");
+       if (IS_ERR(ov7251->analog_regulator)) {
+               dev_err(dev, "cannot get analog regulator\n");
+               return PTR_ERR(ov7251->analog_regulator);
+       }
+
+       ov7251->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
+       if (IS_ERR(ov7251->enable_gpio)) {
+               dev_err(dev, "cannot get enable gpio\n");
+               return PTR_ERR(ov7251->enable_gpio);
+       }
+
+       mutex_init(&ov7251->lock);
+
+       v4l2_ctrl_handler_init(&ov7251->ctrls, 7);
+       ov7251->ctrls.lock = &ov7251->lock;
+
+       v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
+                         V4L2_CID_HFLIP, 0, 1, 1, 0);
+       v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
+                         V4L2_CID_VFLIP, 0, 1, 1, 0);
+       ov7251->exposure = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
+                                            V4L2_CID_EXPOSURE, 1, 32, 1, 32);
+       ov7251->gain = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
+                                        V4L2_CID_GAIN, 16, 1023, 1, 16);
+       v4l2_ctrl_new_std_menu_items(&ov7251->ctrls, &ov7251_ctrl_ops,
+                                    V4L2_CID_TEST_PATTERN,
+                                    ARRAY_SIZE(ov7251_test_pattern_menu) - 1,
+                                    0, 0, ov7251_test_pattern_menu);
+       ov7251->pixel_clock = v4l2_ctrl_new_std(&ov7251->ctrls,
+                                               &ov7251_ctrl_ops,
+                                               V4L2_CID_PIXEL_RATE,
+                                               1, INT_MAX, 1, 1);
+       ov7251->link_freq = v4l2_ctrl_new_int_menu(&ov7251->ctrls,
+                                                  &ov7251_ctrl_ops,
+                                                  V4L2_CID_LINK_FREQ,
+                                                  ARRAY_SIZE(link_freq) - 1,
+                                                  0, link_freq);
+       if (ov7251->link_freq)
+               ov7251->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+       ov7251->sd.ctrl_handler = &ov7251->ctrls;
+
+       if (ov7251->ctrls.error) {
+               dev_err(dev, "%s: control initialization error %d\n",
+                       __func__, ov7251->ctrls.error);
+               ret = ov7251->ctrls.error;
+               goto free_ctrl;
+       }
+
+       v4l2_i2c_subdev_init(&ov7251->sd, client, &ov7251_subdev_ops);
+       ov7251->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+       ov7251->pad.flags = MEDIA_PAD_FL_SOURCE;
+       ov7251->sd.dev = &client->dev;
+       ov7251->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+
+       ret = media_entity_pads_init(&ov7251->sd.entity, 1, &ov7251->pad);
+       if (ret < 0) {
+               dev_err(dev, "could not register media entity\n");
+               goto free_ctrl;
+       }
+
+       ret = ov7251_s_power(&ov7251->sd, true);
+       if (ret < 0) {
+               dev_err(dev, "could not power up OV7251\n");
+               goto free_entity;
+       }
+
+       ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_HIGH, &chip_id_high);
+       if (ret < 0 || chip_id_high != OV7251_CHIP_ID_HIGH_BYTE) {
+               dev_err(dev, "could not read ID high\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+       ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_LOW, &chip_id_low);
+       if (ret < 0 || chip_id_low != OV7251_CHIP_ID_LOW_BYTE) {
+               dev_err(dev, "could not read ID low\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+
+       ret = ov7251_read_reg(ov7251, OV7251_SC_GP_IO_IN1, &chip_rev);
+       if (ret < 0) {
+               dev_err(dev, "could not read revision\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+       chip_rev >>= 4;
+
+       dev_info(dev, "OV7251 revision %x (%s) detected at address 0x%02x\n",
+                chip_rev,
+                chip_rev == 0x4 ? "1A / 1B" :
+                chip_rev == 0x5 ? "1C / 1D" :
+                chip_rev == 0x6 ? "1E" :
+                chip_rev == 0x7 ? "1F" : "unknown",
+                client->addr);
+
+       ret = ov7251_read_reg(ov7251, OV7251_PRE_ISP_00,
+                             &ov7251->pre_isp_00);
+       if (ret < 0) {
+               dev_err(dev, "could not read test pattern value\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+
+       ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT1,
+                             &ov7251->timing_format1);
+       if (ret < 0) {
+               dev_err(dev, "could not read vflip value\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+
+       ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT2,
+                             &ov7251->timing_format2);
+       if (ret < 0) {
+               dev_err(dev, "could not read hflip value\n");
+               ret = -ENODEV;
+               goto power_down;
+       }
+
+       ov7251_s_power(&ov7251->sd, false);
+
+       ret = v4l2_async_register_subdev(&ov7251->sd);
+       if (ret < 0) {
+               dev_err(dev, "could not register v4l2 device\n");
+               goto free_entity;
+       }
+
+       ov7251_entity_init_cfg(&ov7251->sd, NULL);
+
+       return 0;
+
+power_down:
+       ov7251_s_power(&ov7251->sd, false);
+free_entity:
+       media_entity_cleanup(&ov7251->sd.entity);
+free_ctrl:
+       v4l2_ctrl_handler_free(&ov7251->ctrls);
+       mutex_destroy(&ov7251->lock);
+
+       return ret;
+}
+
+static int ov7251_remove(struct i2c_client *client)
+{
+       struct v4l2_subdev *sd = i2c_get_clientdata(client);
+       struct ov7251 *ov7251 = to_ov7251(sd);
+
+       v4l2_async_unregister_subdev(&ov7251->sd);
+       media_entity_cleanup(&ov7251->sd.entity);
+       v4l2_ctrl_handler_free(&ov7251->ctrls);
+       mutex_destroy(&ov7251->lock);
+
+       return 0;
+}
+
+static const struct of_device_id ov7251_of_match[] = {
+       { .compatible = "ovti,ov7251" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ov7251_of_match);
+
+static struct i2c_driver ov7251_i2c_driver = {
+       .driver = {
+               .of_match_table = ov7251_of_match,
+               .name  = "ov7251",
+       },
+       .probe_new  = ov7251_probe,
+       .remove = ov7251_remove,
+};
+
+module_i2c_driver(ov7251_i2c_driver);
+
+MODULE_DESCRIPTION("Omnivision OV7251 Camera Driver");
+MODULE_AUTHOR("Todor Tomov <todor.tomov@linaro.org>");
+MODULE_LICENSE("GPL v2");