From 1b888b3cebef2de3936167e95652830145040b78 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 13 Oct 2020 16:54:00 +0200 Subject: [PATCH] media: v4l: Add a helper for obtaining the link frequency Add a helper for obtaining the link frequency from transmitter drivers. Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- 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) { /* -- 2.11.0