v4l2-common.c 18.4 KB
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/*
 *	Video for Linux Two
 *
 *	A generic video device interface for the LINUX operating system
 *	using a set of device structures/vectors for low level operations.
 *
 *	This file replaces the videodev.c file that comes with the
 *	regular kernel distribution.
 *
 *	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.
 *
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 * Author:	Bill Dirks <bill@thedirks.org>
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 *		based on code by Alan Cox, <alan@cymru.net>
 *
 */

/*
 * Video capture interface for Linux
 *
 *	A generic video device interface for the LINUX operating system
 *	using a set of device structures/vectors for low level operations.
 *
 *		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.
 *
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 * Author:	Alan Cox, <alan@lxorguk.ukuu.org.uk>
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 *
 * Fixes:
 */

/*
 * Video4linux 1/2 integration by Justin Schoeman
 * <justin@suntiger.ee.up.ac.za>
 * 2.4 PROCFS support ported from 2.4 kernels by
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 *  Iñaki García Etxebarria <garetxe@euskalnet.net>
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 * Makefile fix by "W. Michael Petullo" <mike@flyn.org>
 * 2.4 devfs support ported from 2.4 kernels by
 *  Dan Merillat <dan@merillat.org>
 * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
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#include <linux/i2c.h>
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#if defined(CONFIG_SPI)
#include <linux/spi/spi.h>
#endif
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#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/div64.h>
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#include <media/v4l2-common.h>
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#include <media/v4l2-device.h>
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#include <media/v4l2-ctrls.h>
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#include <media/v4l2-chip-ident.h>
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#include <linux/videodev2.h>
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MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
MODULE_LICENSE("GPL");

/*
 *
 *	V 4 L 2   D R I V E R   H E L P E R   A P I
 *
 */

/*
 *  Video Standard Operations (contributed by Michael Schimek)
 */

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/* Helper functions for control handling			     */

/* Check for correctness of the ctrl's value based on the data from
   struct v4l2_queryctrl and the available menu items. Note that
   menu_items may be NULL, in that case it is ignored. */
int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
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		const char * const *menu_items)
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{
	if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
		return -EINVAL;
	if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
		return -EBUSY;
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	if (qctrl->type == V4L2_CTRL_TYPE_STRING)
		return 0;
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	if (qctrl->type == V4L2_CTRL_TYPE_BUTTON ||
	    qctrl->type == V4L2_CTRL_TYPE_INTEGER64 ||
	    qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
		return 0;
	if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum)
		return -ERANGE;
	if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) {
		if (menu_items[ctrl->value] == NULL ||
		    menu_items[ctrl->value][0] == '\0')
			return -EINVAL;
	}
	return 0;
}
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EXPORT_SYMBOL(v4l2_ctrl_check);
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/* Fill in a struct v4l2_queryctrl */
int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
{
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	const char *name;

	v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type,
		       &min, &max, &step, &def, &qctrl->flags);
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	if (name == NULL)
		return -EINVAL;

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	qctrl->minimum = min;
	qctrl->maximum = max;
	qctrl->step = step;
	qctrl->default_value = def;
	qctrl->reserved[0] = qctrl->reserved[1] = 0;
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	strlcpy(qctrl->name, name, sizeof(qctrl->name));
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	return 0;
}
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EXPORT_SYMBOL(v4l2_ctrl_query_fill);
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/* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and
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   the menu. The qctrl pointer may be NULL, in which case it is ignored.
   If menu_items is NULL, then the menu items are retrieved using
   v4l2_ctrl_get_menu. */
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int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl,
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	       const char * const *menu_items)
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{
	int i;

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	qmenu->reserved = 0;
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	if (menu_items == NULL)
		menu_items = v4l2_ctrl_get_menu(qmenu->id);
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	if (menu_items == NULL ||
	    (qctrl && (qmenu->index < qctrl->minimum || qmenu->index > qctrl->maximum)))
		return -EINVAL;
	for (i = 0; i < qmenu->index && menu_items[i]; i++) ;
	if (menu_items[i] == NULL || menu_items[i][0] == '\0')
		return -EINVAL;
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	strlcpy(qmenu->name, menu_items[qmenu->index], sizeof(qmenu->name));
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	return 0;
}
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EXPORT_SYMBOL(v4l2_ctrl_query_menu);
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/* Fill in a struct v4l2_querymenu based on the specified array of valid
   menu items (terminated by V4L2_CTRL_MENU_IDS_END).
   Use this if there are 'holes' in the list of valid menu items. */
int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids)
{
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	const char * const *menu_items = v4l2_ctrl_get_menu(qmenu->id);
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	qmenu->reserved = 0;
	if (menu_items == NULL || ids == NULL)
		return -EINVAL;
	while (*ids != V4L2_CTRL_MENU_IDS_END) {
		if (*ids++ == qmenu->index) {
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			strlcpy(qmenu->name, menu_items[qmenu->index],
					sizeof(qmenu->name));
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			return 0;
		}
	}
	return -EINVAL;
}
EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items);

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/* ctrl_classes points to an array of u32 pointers, the last element is
   a NULL pointer. Each u32 array is a 0-terminated array of control IDs.
   Each array must be sorted low to high and belong to the same control
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   class. The array of u32 pointers must also be sorted, from low class IDs
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   to high class IDs.

   This function returns the first ID that follows after the given ID.
   When no more controls are available 0 is returned. */
u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id)
{
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	u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
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	const u32 *pctrl;

	if (ctrl_classes == NULL)
		return 0;
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	/* if no query is desired, then check if the ID is part of ctrl_classes */
	if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) {
		/* find class */
		while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class)
			ctrl_classes++;
		if (*ctrl_classes == NULL)
			return 0;
		pctrl = *ctrl_classes;
		/* find control ID */
		while (*pctrl && *pctrl != id) pctrl++;
		return *pctrl ? id : 0;
	}
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	id &= V4L2_CTRL_ID_MASK;
	id++;	/* select next control */
	/* find first class that matches (or is greater than) the class of
	   the ID */
	while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) < ctrl_class)
		ctrl_classes++;
	/* no more classes */
	if (*ctrl_classes == NULL)
		return 0;
	pctrl = *ctrl_classes;
	/* find first ctrl within the class that is >= ID */
	while (*pctrl && *pctrl < id) pctrl++;
	if (*pctrl)
		return *pctrl;
	/* we are at the end of the controls of the current class. */
	/* continue with next class if available */
	ctrl_classes++;
	if (*ctrl_classes == NULL)
		return 0;
	return **ctrl_classes;
}
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EXPORT_SYMBOL(v4l2_ctrl_next);
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int v4l2_chip_match_host(const struct v4l2_dbg_match *match)
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{
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	switch (match->type) {
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	case V4L2_CHIP_MATCH_HOST:
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		return match->addr == 0;
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	default:
		return 0;
	}
}
EXPORT_SYMBOL(v4l2_chip_match_host);

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
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int v4l2_chip_match_i2c_client(struct i2c_client *c, const struct v4l2_dbg_match *match)
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{
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	int len;

	if (c == NULL || match == NULL)
		return 0;

	switch (match->type) {
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	case V4L2_CHIP_MATCH_I2C_DRIVER:
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		if (c->driver == NULL || c->driver->driver.name == NULL)
			return 0;
		len = strlen(c->driver->driver.name);
		/* legacy drivers have a ' suffix, don't try to match that */
		if (len && c->driver->driver.name[len - 1] == '\'')
			len--;
		return len && !strncmp(c->driver->driver.name, match->name, len);
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	case V4L2_CHIP_MATCH_I2C_ADDR:
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		return c->addr == match->addr;
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	default:
		return 0;
	}
}
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EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
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int v4l2_chip_ident_i2c_client(struct i2c_client *c, struct v4l2_dbg_chip_ident *chip,
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		u32 ident, u32 revision)
{
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	if (!v4l2_chip_match_i2c_client(c, &chip->match))
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		return 0;
	if (chip->ident == V4L2_IDENT_NONE) {
		chip->ident = ident;
		chip->revision = revision;
	}
	else {
		chip->ident = V4L2_IDENT_AMBIGUOUS;
		chip->revision = 0;
	}
	return 0;
}
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EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
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/* ----------------------------------------------------------------- */

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/* I2C Helper functions */
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void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
		const struct v4l2_subdev_ops *ops)
{
	v4l2_subdev_init(sd, ops);
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	sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
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	/* the owner is the same as the i2c_client's driver owner */
	sd->owner = client->driver->driver.owner;
	/* i2c_client and v4l2_subdev point to one another */
	v4l2_set_subdevdata(sd, client);
	i2c_set_clientdata(client, sd);
	/* initialize name */
	snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
		client->driver->driver.name, i2c_adapter_id(client->adapter),
		client->addr);
}
EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);



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/* Load an i2c sub-device. */
struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
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		struct i2c_adapter *adapter, struct i2c_board_info *info,
		const unsigned short *probe_addrs)
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{
	struct v4l2_subdev *sd = NULL;
	struct i2c_client *client;

	BUG_ON(!v4l2_dev);

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	request_module(I2C_MODULE_PREFIX "%s", info->type);
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	/* Create the i2c client */
	if (info->addr == 0 && probe_addrs)
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		client = i2c_new_probed_device(adapter, info, probe_addrs,
					       NULL);
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	else
		client = i2c_new_device(adapter, info);

	/* Note: by loading the module first we are certain that c->driver
	   will be set if the driver was found. If the module was not loaded
	   first, then the i2c core tries to delay-load the module for us,
	   and then c->driver is still NULL until the module is finally
	   loaded. This delay-load mechanism doesn't work if other drivers
	   want to use the i2c device, so explicitly loading the module
	   is the best alternative. */
	if (client == NULL || client->driver == NULL)
		goto error;

	/* Lock the module so we can safely get the v4l2_subdev pointer */
	if (!try_module_get(client->driver->driver.owner))
		goto error;
	sd = i2c_get_clientdata(client);

	/* Register with the v4l2_device which increases the module's
	   use count as well. */
	if (v4l2_device_register_subdev(v4l2_dev, sd))
		sd = NULL;
	/* Decrease the module use count to match the first try_module_get. */
	module_put(client->driver->driver.owner);

error:
	/* If we have a client but no subdev, then something went wrong and
	   we must unregister the client. */
	if (client && sd == NULL)
		i2c_unregister_device(client);
	return sd;
}
EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board);

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struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
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		struct i2c_adapter *adapter, const char *client_type,
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		u8 addr, const unsigned short *probe_addrs)
{
	struct i2c_board_info info;

	/* Setup the i2c board info with the device type and
	   the device address. */
	memset(&info, 0, sizeof(info));
	strlcpy(info.type, client_type, sizeof(info.type));
	info.addr = addr;

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	return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs);
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}
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EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
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/* Return i2c client address of v4l2_subdev. */
unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	return client ? client->addr : I2C_CLIENT_END;
}
EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr);

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/* Return a list of I2C tuner addresses to probe. Use only if the tuner
   addresses are unknown. */
const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)
{
	static const unsigned short radio_addrs[] = {
#if defined(CONFIG_MEDIA_TUNER_TEA5761) || defined(CONFIG_MEDIA_TUNER_TEA5761_MODULE)
		0x10,
#endif
		0x60,
		I2C_CLIENT_END
	};
	static const unsigned short demod_addrs[] = {
		0x42, 0x43, 0x4a, 0x4b,
		I2C_CLIENT_END
	};
	static const unsigned short tv_addrs[] = {
		0x42, 0x43, 0x4a, 0x4b,		/* tda8290 */
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		0x60, 0x61, 0x62, 0x63, 0x64,
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		I2C_CLIENT_END
	};

	switch (type) {
	case ADDRS_RADIO:
		return radio_addrs;
	case ADDRS_DEMOD:
		return demod_addrs;
	case ADDRS_TV:
		return tv_addrs;
	case ADDRS_TV_WITH_DEMOD:
		return tv_addrs + 4;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs);

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#endif /* defined(CONFIG_I2C) */

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#if defined(CONFIG_SPI)

/* Load a spi sub-device. */

void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
		const struct v4l2_subdev_ops *ops)
{
	v4l2_subdev_init(sd, ops);
	sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
	/* the owner is the same as the spi_device's driver owner */
	sd->owner = spi->dev.driver->owner;
	/* spi_device and v4l2_subdev point to one another */
	v4l2_set_subdevdata(sd, spi);
	spi_set_drvdata(spi, sd);
	/* initialize name */
	strlcpy(sd->name, spi->dev.driver->name, sizeof(sd->name));
}
EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);

struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
		struct spi_master *master, struct spi_board_info *info)
{
	struct v4l2_subdev *sd = NULL;
	struct spi_device *spi = NULL;

	BUG_ON(!v4l2_dev);

	if (info->modalias)
		request_module(info->modalias);

	spi = spi_new_device(master, info);

	if (spi == NULL || spi->dev.driver == NULL)
		goto error;

	if (!try_module_get(spi->dev.driver->owner))
		goto error;

	sd = spi_get_drvdata(spi);

	/* Register with the v4l2_device which increases the module's
	   use count as well. */
	if (v4l2_device_register_subdev(v4l2_dev, sd))
		sd = NULL;

	/* Decrease the module use count to match the first try_module_get. */
	module_put(spi->dev.driver->owner);

error:
	/* If we have a client but no subdev, then something went wrong and
	   we must unregister the client. */
	if (spi && sd == NULL)
		spi_unregister_device(spi);

	return sd;
}
EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);

#endif /* defined(CONFIG_SPI) */

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/* Clamp x to be between min and max, aligned to a multiple of 2^align.  min
 * and max don't have to be aligned, but there must be at least one valid
 * value.  E.g., min=17,max=31,align=4 is not allowed as there are no multiples
 * of 16 between 17 and 31.  */
static unsigned int clamp_align(unsigned int x, unsigned int min,
				unsigned int max, unsigned int align)
{
	/* Bits that must be zero to be aligned */
	unsigned int mask = ~((1 << align) - 1);

	/* Round to nearest aligned value */
	if (align)
		x = (x + (1 << (align - 1))) & mask;

	/* Clamp to aligned value of min and max */
	if (x < min)
		x = (min + ~mask) & mask;
	else if (x > max)
		x = max & mask;

	return x;
}

/* Bound an image to have a width between wmin and wmax, and height between
 * hmin and hmax, inclusive.  Additionally, the width will be a multiple of
 * 2^walign, the height will be a multiple of 2^halign, and the overall size
 * (width*height) will be a multiple of 2^salign.  The image may be shrunk
 * or enlarged to fit the alignment constraints.
 *
 * The width or height maximum must not be smaller than the corresponding
 * minimum.  The alignments must not be so high there are no possible image
 * sizes within the allowed bounds.  wmin and hmin must be at least 1
 * (don't use 0).  If you don't care about a certain alignment, specify 0,
 * as 2^0 is 1 and one byte alignment is equivalent to no alignment.  If
 * you only want to adjust downward, specify a maximum that's the same as
 * the initial value.
 */
void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax,
			   unsigned int walign,
			   u32 *h, unsigned int hmin, unsigned int hmax,
			   unsigned int halign, unsigned int salign)
{
	*w = clamp_align(*w, wmin, wmax, walign);
	*h = clamp_align(*h, hmin, hmax, halign);

	/* Usually we don't need to align the size and are done now. */
	if (!salign)
		return;

	/* How much alignment do we have? */
	walign = __ffs(*w);
	halign = __ffs(*h);
	/* Enough to satisfy the image alignment? */
	if (walign + halign < salign) {
		/* Max walign where there is still a valid width */
		unsigned int wmaxa = __fls(wmax ^ (wmin - 1));
		/* Max halign where there is still a valid height */
		unsigned int hmaxa = __fls(hmax ^ (hmin - 1));

		/* up the smaller alignment until we have enough */
		do {
			if (halign >= hmaxa ||
			    (walign <= halign && walign < wmaxa)) {
				*w = clamp_align(*w, wmin, wmax, walign + 1);
				walign = __ffs(*w);
			} else {
				*h = clamp_align(*h, hmin, hmax, halign + 1);
				halign = __ffs(*h);
			}
		} while (halign + walign < salign);
	}
}
EXPORT_SYMBOL_GPL(v4l_bound_align_image);
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/**
 * v4l_fill_dv_preset_info - fill description of a digital video preset
 * @preset - preset value
 * @info - pointer to struct v4l2_dv_enum_preset
 *
 * drivers can use this helper function to fill description of dv preset
 * in info.
 */
int v4l_fill_dv_preset_info(u32 preset, struct v4l2_dv_enum_preset *info)
{
	static const struct v4l2_dv_preset_info {
		u16 width;
		u16 height;
		const char *name;
	} dv_presets[] = {
		{ 0, 0, "Invalid" },		/* V4L2_DV_INVALID */
		{ 720,  480, "480p@59.94" },	/* V4L2_DV_480P59_94 */
		{ 720,  576, "576p@50" },	/* V4L2_DV_576P50 */
		{ 1280, 720, "720p@24" },	/* V4L2_DV_720P24 */
		{ 1280, 720, "720p@25" },	/* V4L2_DV_720P25 */
		{ 1280, 720, "720p@30" },	/* V4L2_DV_720P30 */
		{ 1280, 720, "720p@50" },	/* V4L2_DV_720P50 */
		{ 1280, 720, "720p@59.94" },	/* V4L2_DV_720P59_94 */
		{ 1280, 720, "720p@60" },	/* V4L2_DV_720P60 */
		{ 1920, 1080, "1080i@29.97" },	/* V4L2_DV_1080I29_97 */
		{ 1920, 1080, "1080i@30" },	/* V4L2_DV_1080I30 */
		{ 1920, 1080, "1080i@25" },	/* V4L2_DV_1080I25 */
		{ 1920, 1080, "1080i@50" },	/* V4L2_DV_1080I50 */
		{ 1920, 1080, "1080i@60" },	/* V4L2_DV_1080I60 */
		{ 1920, 1080, "1080p@24" },	/* V4L2_DV_1080P24 */
		{ 1920, 1080, "1080p@25" },	/* V4L2_DV_1080P25 */
		{ 1920, 1080, "1080p@30" },	/* V4L2_DV_1080P30 */
		{ 1920, 1080, "1080p@50" },	/* V4L2_DV_1080P50 */
		{ 1920, 1080, "1080p@60" },	/* V4L2_DV_1080P60 */
	};

	if (info == NULL || preset >= ARRAY_SIZE(dv_presets))
		return -EINVAL;

	info->preset = preset;
	info->width = dv_presets[preset].width;
	info->height = dv_presets[preset].height;
	strlcpy(info->name, dv_presets[preset].name, sizeof(info->name));
	return 0;
}
EXPORT_SYMBOL_GPL(v4l_fill_dv_preset_info);
597

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const struct v4l2_frmsize_discrete *v4l2_find_nearest_format(
		const struct v4l2_discrete_probe *probe,
		s32 width, s32 height)
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{
	int i;
	u32 error, min_error = UINT_MAX;
604
	const struct v4l2_frmsize_discrete *size, *best = NULL;
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	if (!probe)
		return best;

	for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) {
		error = abs(size->width - width) + abs(size->height - height);
		if (error < min_error) {
			min_error = error;
			best = size;
		}
		if (!error)
			break;
	}

	return best;
}
EXPORT_SYMBOL_GPL(v4l2_find_nearest_format);