Add a helper for obtaining the link frequency from transmitter drivers.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-common.c | 33 +++++++++++++++++++++++++++
include/media/v4l2-common.h | 21 +++++++++++++++++
2 files changed, 54 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 3dc17ebe14fa..78007dba4677 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -441,3 +441,36 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
+
+s64 v4l2_get_link_rate(struct v4l2_ctrl_handler *handler, unsigned int mul,
+ unsigned int div)
+{
+ struct v4l2_ctrl *ctrl;
+ s64 freq;
+
+ ctrl = v4l2_ctrl_find(handler, V4L2_CID_LINK_FREQ);
+ if (ctrl) {
+ struct v4l2_querymenu qm = { .id = V4L2_CID_LINK_FREQ };
+ int ret;
+
+ qm.index = v4l2_ctrl_g_ctrl(ctrl);
+
+ ret = v4l2_querymenu(handler, &qm);
+ if (ret)
+ return -ENOENT;
+
+ freq = qm.value;
+ } else {
+ if (!mul || !div)
+ return -ENOENT;
+
+ ctrl = v4l2_ctrl_find(handler, V4L2_CID_PIXEL_RATE);
+ if (!ctrl)
+ return -ENOENT;
+
+ freq = div_u64(v4l2_ctrl_g_ctrl_int64(ctrl) * mul, div);
+ }
+
+ return freq > 0 ? freq : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(v4l2_get_link_rate);
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index a3083529b698..be36cbdcc1bd 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -519,6 +519,27 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
u32 width, u32 height);
+/**
+ * v4l2_get_link_rate - Get link rate from transmitter
+ *
+ * @handler: The transmitter's control handler
+ * @mul: The multiplier between pixel rate and link frequency. Bits per pixel on
+ * D-PHY, samples per clock on parallel. 0 otherwise.
+ * @div: The divisor between pixel rate and link frequency. Number of data lanes
+ * times two on D-PHY, 1 on parallel. 0 otherwise.
+ *
+ * This function is intended for obtaining the link frequency from the
+ * transmitter sub-devices. It returns the link rate, either from the
+ * V4L2_CID_LINK_FREQ control implemented by the transmitter, or value
+ * calculated based on the V4L2_CID_PIXEL_RATE implemented by the transmitter.
+ *
+ * Returns link frequency on success, otherwise a negative error code:
+ * -ENOENT: Link frequency or pixel rate control not found
+ * -EINVAL: Invalid link frequency value
+ */
+s64 v4l2_get_link_rate(struct v4l2_ctrl_handler *handler, unsigned int mul,
+ unsigned int div);
+
static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf)
{
/*
--
2.27.0
