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Diffstat (limited to 'drivers/media/v4l2-core/v4l2-common.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-common.c623
1 files changed, 623 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
new file mode 100644
index 000000000000..105f88cdb9d6
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -0,0 +1,623 @@
+/*
+ * 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.
+ *
+ * Author: Bill Dirks <bill@thedirks.org>
+ * 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.
+ *
+ * Author: Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ *
+ * Fixes:
+ */
+
+/*
+ * Video4linux 1/2 integration by Justin Schoeman
+ * <justin@suntiger.ee.up.ac.za>
+ * 2.4 PROCFS support ported from 2.4 kernels by
+ * Iñaki García Etxebarria <garetxe@euskalnet.net>
+ * 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>
+#include <linux/i2c.h>
+#if defined(CONFIG_SPI)
+#include <linux/spi/spi.h>
+#endif
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#include <asm/div64.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-chip-ident.h>
+
+#include <linux/videodev2.h>
+
+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)
+ */
+
+/* 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,
+ const char * const *menu_items)
+{
+ if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
+ return -EINVAL;
+ if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
+ return -EBUSY;
+ if (qctrl->type == V4L2_CTRL_TYPE_STRING)
+ return 0;
+ 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;
+ }
+ if (qctrl->type == V4L2_CTRL_TYPE_BITMASK &&
+ (ctrl->value & ~qctrl->maximum))
+ return -ERANGE;
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_ctrl_check);
+
+/* Fill in a struct v4l2_queryctrl */
+int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
+{
+ const char *name;
+
+ v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type,
+ &min, &max, &step, &def, &qctrl->flags);
+
+ if (name == NULL)
+ return -EINVAL;
+
+ qctrl->minimum = min;
+ qctrl->maximum = max;
+ qctrl->step = step;
+ qctrl->default_value = def;
+ qctrl->reserved[0] = qctrl->reserved[1] = 0;
+ strlcpy(qctrl->name, name, sizeof(qctrl->name));
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_ctrl_query_fill);
+
+/* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and
+ 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. */
+int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl,
+ const char * const *menu_items)
+{
+ int i;
+
+ qmenu->reserved = 0;
+ if (menu_items == NULL)
+ menu_items = v4l2_ctrl_get_menu(qmenu->id);
+ 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;
+ strlcpy(qmenu->name, menu_items[qmenu->index], sizeof(qmenu->name));
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_ctrl_query_menu);
+
+/* 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)
+{
+ const char * const *menu_items = v4l2_ctrl_get_menu(qmenu->id);
+
+ qmenu->reserved = 0;
+ if (menu_items == NULL || ids == NULL)
+ return -EINVAL;
+ while (*ids != V4L2_CTRL_MENU_IDS_END) {
+ if (*ids++ == qmenu->index) {
+ strlcpy(qmenu->name, menu_items[qmenu->index],
+ sizeof(qmenu->name));
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items);
+
+/* 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
+ class. The array of u32 pointers must also be sorted, from low class IDs
+ 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)
+{
+ u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
+ const u32 *pctrl;
+
+ if (ctrl_classes == NULL)
+ return 0;
+
+ /* 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;
+ }
+ 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;
+}
+EXPORT_SYMBOL(v4l2_ctrl_next);
+
+int v4l2_chip_match_host(const struct v4l2_dbg_match *match)
+{
+ switch (match->type) {
+ case V4L2_CHIP_MATCH_HOST:
+ return match->addr == 0;
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(v4l2_chip_match_host);
+
+#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
+int v4l2_chip_match_i2c_client(struct i2c_client *c, const struct v4l2_dbg_match *match)
+{
+ int len;
+
+ if (c == NULL || match == NULL)
+ return 0;
+
+ switch (match->type) {
+ case V4L2_CHIP_MATCH_I2C_DRIVER:
+ 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);
+ case V4L2_CHIP_MATCH_I2C_ADDR:
+ return c->addr == match->addr;
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(v4l2_chip_match_i2c_client);
+
+int v4l2_chip_ident_i2c_client(struct i2c_client *c, struct v4l2_dbg_chip_ident *chip,
+ u32 ident, u32 revision)
+{
+ if (!v4l2_chip_match_i2c_client(c, &chip->match))
+ 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;
+}
+EXPORT_SYMBOL(v4l2_chip_ident_i2c_client);
+
+/* ----------------------------------------------------------------- */
+
+/* I2C Helper functions */
+
+
+void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
+ const struct v4l2_subdev_ops *ops)
+{
+ v4l2_subdev_init(sd, ops);
+ sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
+ /* 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);
+
+
+
+/* Load an i2c sub-device. */
+struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
+ struct i2c_adapter *adapter, struct i2c_board_info *info,
+ const unsigned short *probe_addrs)
+{
+ struct v4l2_subdev *sd = NULL;
+ struct i2c_client *client;
+
+ BUG_ON(!v4l2_dev);
+
+ request_module(I2C_MODULE_PREFIX "%s", info->type);
+
+ /* Create the i2c client */
+ if (info->addr == 0 && probe_addrs)
+ client = i2c_new_probed_device(adapter, info, probe_addrs,
+ NULL);
+ 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);
+
+struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
+ struct i2c_adapter *adapter, const char *client_type,
+ 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;
+
+ return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs);
+}
+EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
+
+/* 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);
+
+/* 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 */
+ 0x60, 0x61, 0x62, 0x63, 0x64,
+ 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);
+
+#endif /* defined(CONFIG_I2C) */
+
+#if defined(CONFIG_SPI)
+
+/* Load an 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) */
+
+/* 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);
+
+/**
+ * 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);
+
+const struct v4l2_frmsize_discrete *v4l2_find_nearest_format(
+ const struct v4l2_discrete_probe *probe,
+ s32 width, s32 height)
+{
+ int i;
+ u32 error, min_error = UINT_MAX;
+ const struct v4l2_frmsize_discrete *size, *best = NULL;
+
+ 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);

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