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media: v4l: Add a helper for setting up link-frequencies control

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Add a helper for obtaining supported link frequencies in form most drivers
need them. The result is a bitmap of supported controls.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Sakari Ailus 2024-01-08 16:18:02 +01:00 committed by Mauro Carvalho Chehab
parent 45db5c214c
commit a68e88e2cf
2 changed files with 72 additions and 0 deletions
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47
drivers/media/v4l2-core/v4l2-common.c
View file

@ -585,3 +585,50 @@ u32 v4l2_fraction_to_interval(u32 numerator, u32 denominator)
return denominator ? numerator * multiplier / denominator : 0;
}
EXPORT_SYMBOL_GPL(v4l2_fraction_to_interval);
int v4l2_link_freq_to_bitmap(struct device *dev, const u64 *fw_link_freqs,
unsigned int num_of_fw_link_freqs,
const s64 *driver_link_freqs,
unsigned int num_of_driver_link_freqs,
unsigned long *bitmap)
{
unsigned int i;
*bitmap = 0;
if (!num_of_fw_link_freqs) {
dev_err(dev, "no link frequencies in firmware\n");
return -ENODATA;
}
for (i = 0; i < num_of_fw_link_freqs; i++) {
unsigned int j;
for (j = 0; j < num_of_driver_link_freqs; j++) {
if (fw_link_freqs[i] != driver_link_freqs[j])
continue;
dev_dbg(dev, "enabling link frequency %lld Hz\n",
driver_link_freqs[j]);
*bitmap |= BIT(j);
break;
}
}
if (!*bitmap) {
dev_err(dev, "no matching link frequencies found\n");
dev_dbg(dev, "specified in firmware:\n");
for (i = 0; i < num_of_fw_link_freqs; i++)
dev_dbg(dev, "\t%llu Hz\n", fw_link_freqs[i]);
dev_dbg(dev, "driver supported:\n");
for (i = 0; i < num_of_driver_link_freqs; i++)
dev_dbg(dev, "\t%lld Hz\n", driver_link_freqs[i]);
return -ENOENT;
}
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_link_freq_to_bitmap);

25
include/media/v4l2-common.h
View file

@ -547,6 +547,31 @@ void v4l2_simplify_fraction(u32 *numerator, u32 *denominator,
unsigned int n_terms, unsigned int threshold);
u32 v4l2_fraction_to_interval(u32 numerator, u32 denominator);
/**
* v4l2_link_freq_to_bitmap - Figure out platform-supported link frequencies
* @dev: The struct device
* @fw_link_freqs: Array of link frequencies from firmware
* @num_of_fw_link_freqs: Number of entries in @fw_link_freqs
* @driver_link_freqs: Array of link frequencies supported by the driver
* @num_of_driver_link_freqs: Number of entries in @driver_link_freqs
* @bitmap: Bitmap of driver-supported link frequencies found in @fw_link_freqs
*
* This function checks which driver-supported link frequencies are enabled in
* system firmware and sets the corresponding bits in @bitmap (after first
* zeroing it).
*
* Return values:
* 0: Success
* -ENOENT: No match found between driver-supported link frequencies and
* those available in firmware.
* -ENODATA: No link frequencies were specified in firmware.
*/
int v4l2_link_freq_to_bitmap(struct device *dev, const u64 *fw_link_freqs,
unsigned int num_of_fw_link_freqs,
const s64 *driver_link_freqs,
unsigned int num_of_driver_link_freqs,
unsigned long *bitmap);
static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf)
{
/*