Commit 75e2bdad authored by Daniel Drake's avatar Daniel Drake Committed by Mauro Carvalho Chehab
Browse files

[media] ov7670: allow configuration of image size, clock speed, and I/O method 



These parameters need to be configurable based on the host system.
They can now be communicated through the s_config call.

The old CONFIG_OLPC_XO_1 selector was not correct; this kind of
arrangement wouldn't allow for a universal kernel that would work on both
laptops.

Certain parts of the probe routine had to be moved later (into s_config),
because we can't do any I/O until we know which I/O method has been
selected through this mechanism.

Signed-off-by: default avatarDaniel Drake <dsd@laptop.org>
Acked-by: default avatarJonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent f8c61274

drivers/media/video/ov7670.c

+95 −38
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <media/v4l2-chip-ident.h>

#include <media/v4l2-mediabus.h>



#include "ov7670.h"



MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");

MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
@@ -42,11 +43,6 @@ MODULE_PARM_DESC(debug, "Debug level (0-1)"); 
#define QCIF_WIDTH	176

#define	QCIF_HEIGHT	144



/*

 * Our nominal (default) frame rate.

 */

#define OV7670_FRAME_RATE 30



/*

 * The 7670 sits on i2c with ID 0x42

 */
@@ -198,7 +194,11 @@ struct ov7670_info { 
	struct ov7670_format_struct *fmt;  /* Current format */

	unsigned char sat;		/* Saturation value */

	int hue;			/* Hue value */

	int min_width;			/* Filter out smaller sizes */

	int min_height;			/* Filter out smaller sizes */

	int clock_speed;		/* External clock speed (MHz) */

	u8 clkrc;			/* Clock divider value */

	bool use_smbus;			/* Use smbus I/O instead of I2C */

};



static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
@@ -415,8 +415,7 @@ static struct regval_list ov7670_fmt_raw[] = { 
 * ov7670 is not really an SMBUS device, though, so the communication

 * is not always entirely reliable.

 */

#ifdef CONFIG_OLPC_XO_1

static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,

static int ov7670_read_smbus(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char *value)

{

	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -431,7 +430,7 @@ static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg, 
}





static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,

static int ov7670_write_smbus(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char value)

{

	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -442,11 +441,10 @@ static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg, 
	return ret;

}



#else /* ! CONFIG_OLPC_XO_1 */

/*

 * On most platforms, we'd rather do straight i2c I/O.

 */

static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,

static int ov7670_read_i2c(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char *value)

{

	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -479,7 +477,7 @@ static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg, 
}





static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,

static int ov7670_write_i2c(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char value)

{

	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -498,8 +496,26 @@ static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg, 
		msleep(5);  /* Wait for reset to run */

	return ret;

}

#endif /* CONFIG_OLPC_XO_1 */



static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char *value)

{

	struct ov7670_info *info = to_state(sd);

	if (info->use_smbus)

		return ov7670_read_smbus(sd, reg, value);

	else

		return ov7670_read_i2c(sd, reg, value);

}



static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,

		unsigned char value)

{

	struct ov7670_info *info = to_state(sd);

	if (info->use_smbus)

		return ov7670_write_smbus(sd, reg, value);

	else

		return ov7670_write_i2c(sd, reg, value);

}



/*

 * Write a list of register settings; ff/ff stops the process.
@@ -854,7 +870,7 @@ static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) 
	memset(cp, 0, sizeof(struct v4l2_captureparm));

	cp->capability = V4L2_CAP_TIMEPERFRAME;

	cp->timeperframe.numerator = 1;

	cp->timeperframe.denominator = OV7670_FRAME_RATE;

	cp->timeperframe.denominator = info->clock_speed;

	if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)

		cp->timeperframe.denominator /= (info->clkrc & CLK_SCALE);

	return 0;
@@ -875,14 +891,14 @@ static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) 
	if (tpf->numerator == 0 || tpf->denominator == 0)

		div = 1;  /* Reset to full rate */

	else

		div = (tpf->numerator*OV7670_FRAME_RATE)/tpf->denominator;

		div = (tpf->numerator * info->clock_speed) / tpf->denominator;

	if (div == 0)

		div = 1;

	else if (div > CLK_SCALE)

		div = CLK_SCALE;

	info->clkrc = (info->clkrc & 0x80) | div;

	tpf->numerator = 1;

	tpf->denominator = OV7670_FRAME_RATE/div;

	tpf->denominator = info->clock_speed / div;

	return ov7670_write(sd, REG_CLKRC, info->clkrc);

}
@@ -912,15 +928,31 @@ static int ov7670_enum_frameintervals(struct v4l2_subdev *sd, 
static int ov7670_enum_framesizes(struct v4l2_subdev *sd,

		struct v4l2_frmsizeenum *fsize)

{

	struct ov7670_info *info = to_state(sd);

	int i;

	int num_valid = -1;

	__u32 index = fsize->index;

	if (index >= N_WIN_SIZES)

		return -EINVAL;



	/*

	 * If a minimum width/height was requested, filter out the capture

	 * windows that fall outside that.

	 */

	for (i = 0; i < N_WIN_SIZES; i++) {

		struct ov7670_win_size *win = &ov7670_win_sizes[index];

		if (info->min_width && win->width < info->min_width)

			continue;

		if (info->min_height && win->height < info->min_height)

			continue;

		if (index == ++num_valid) {

			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;

	fsize->discrete.width = ov7670_win_sizes[index].width;

	fsize->discrete.height = ov7670_win_sizes[index].height;

			fsize->discrete.width = win->width;

			fsize->discrete.height = win->height;

			return 0;

		}

	}



	return -EINVAL;

}



/*

 * Code for dealing with controls.
@@ -1417,6 +1449,47 @@ static int ov7670_g_chip_ident(struct v4l2_subdev *sd, 
	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_OV7670, 0);

}



static int ov7670_s_config(struct v4l2_subdev *sd, int dumb, void *data)

{

	struct i2c_client *client = v4l2_get_subdevdata(sd);

	struct ov7670_config *config = data;

	struct ov7670_info *info = to_state(sd);

	int ret;



	info->clock_speed = 30; /* default: a guess */



	/*

	 * Must apply configuration before initializing device, because it

	 * selects I/O method.

	 */

	if (config) {

		info->min_width = config->min_width;

		info->min_height = config->min_height;

		info->use_smbus = config->use_smbus;



		if (config->clock_speed)

			info->clock_speed = config->clock_speed;

	}



	/* Make sure it's an ov7670 */

	ret = ov7670_detect(sd);

	if (ret) {

		v4l_dbg(1, debug, client,

			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",

			client->addr << 1, client->adapter->name);

		kfree(info);

		return ret;

	}

	v4l_info(client, "chip found @ 0x%02x (%s)\n",

			client->addr << 1, client->adapter->name);



	info->fmt = &ov7670_formats[0];

	info->sat = 128;	/* Review this */

	info->clkrc = info->clock_speed / 30;



	return 0;

}



#ifdef CONFIG_VIDEO_ADV_DEBUG

static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)

{
@@ -1455,6 +1528,7 @@ static const struct v4l2_subdev_core_ops ov7670_core_ops = { 
	.s_ctrl = ov7670_s_ctrl,

	.queryctrl = ov7670_queryctrl,

	.reset = ov7670_reset,

	.s_config = ov7670_s_config,

	.init = ov7670_init,

#ifdef CONFIG_VIDEO_ADV_DEBUG

	.g_register = ov7670_g_register,
@@ -1484,7 +1558,6 @@ static int ov7670_probe(struct i2c_client *client, 
{

	struct v4l2_subdev *sd;

	struct ov7670_info *info;

	int ret;



	info = kzalloc(sizeof(struct ov7670_info), GFP_KERNEL);

	if (info == NULL)
@@ -1492,22 +1565,6 @@ static int ov7670_probe(struct i2c_client *client, 
	sd = &info->sd;

	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);



	/* Make sure it's an ov7670 */

	ret = ov7670_detect(sd);

	if (ret) {

		v4l_dbg(1, debug, client,

			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",

			client->addr << 1, client->adapter->name);

		kfree(info);

		return ret;

	}

	v4l_info(client, "chip found @ 0x%02x (%s)\n",

			client->addr << 1, client->adapter->name);



	info->fmt = &ov7670_formats[0];

	info->sat = 128;	/* Review this */

	info->clkrc = 1;	/* 30fps */



	return 0;

}

drivers/media/video/ov7670.h

0 → 100644
+20 −0
Original line number Diff line number Diff line 
/*

 * A V4L2 driver for OmniVision OV7670 cameras.

 *

 * Copyright 2010 One Laptop Per Child

 *

 * This file may be distributed under the terms of the GNU General

 * Public License, version 2.

 */



#ifndef __OV7670_H

#define __OV7670_H



struct ov7670_config {

	int min_width;			/* Filter out smaller sizes */

	int min_height;			/* Filter out smaller sizes */

	int clock_speed;		/* External clock speed (MHz) */

	bool use_smbus;			/* Use smbus I/O instead of I2C */

};



#endif

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