Commit fb30ee79 authored by Philipp Zabel's avatar Philipp Zabel Committed by Mauro Carvalho Chehab

[media] media: imx: csi: add frame skipping support

The CSI can skip any out of up to 6 input frames, allowing to reduce the
frame rate at the output pads by small fractions.
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarSteve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 6f303592
......@@ -2,6 +2,7 @@
* V4L2 Capture CSI Subdev for Freescale i.MX5/6 SOC
*
* Copyright (c) 2014-2017 Mentor Graphics Inc.
* Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
*
* 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
......@@ -9,6 +10,7 @@
* (at your option) any later version.
*/
#include <linux/delay.h>
#include <linux/gcd.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
......@@ -42,6 +44,18 @@
#define H_ALIGN 1 /* multiple of 2 lines */
#define S_ALIGN 1 /* multiple of 2 */
/*
* struct csi_skip_desc - CSI frame skipping descriptor
* @keep - number of frames kept per max_ratio frames
* @max_ratio - width of skip_smfc, written to MAX_RATIO bitfield
* @skip_smfc - skip pattern written to the SKIP_SMFC bitfield
*/
struct csi_skip_desc {
u8 keep;
u8 max_ratio;
u8 skip_smfc;
};
struct csi_priv {
struct device *dev;
struct ipu_soc *ipu;
......@@ -65,8 +79,9 @@ struct csi_priv {
struct v4l2_mbus_framefmt format_mbus[CSI_NUM_PADS];
const struct imx_media_pixfmt *cc[CSI_NUM_PADS];
struct v4l2_fract frame_interval;
struct v4l2_fract frame_interval[CSI_NUM_PADS];
struct v4l2_rect crop;
const struct csi_skip_desc *skip;
/* active vb2 buffers to send to video dev sink */
struct imx_media_buffer *active_vb2_buf[2];
......@@ -581,6 +596,10 @@ static int csi_setup(struct csi_priv *priv)
ipu_csi_set_dest(priv->csi, priv->dest);
if (priv->dest == IPU_CSI_DEST_IDMAC)
ipu_csi_set_skip_smfc(priv->csi, priv->skip->skip_smfc,
priv->skip->max_ratio - 1, 0);
ipu_csi_dump(priv->csi);
return 0;
......@@ -588,6 +607,7 @@ static int csi_setup(struct csi_priv *priv)
static int csi_start(struct csi_priv *priv)
{
struct v4l2_fract *output_fi, *input_fi;
u32 bad_frames = 0;
int ret;
......@@ -596,10 +616,12 @@ static int csi_start(struct csi_priv *priv)
return -EINVAL;
}
output_fi = &priv->frame_interval[priv->active_output_pad];
input_fi = &priv->frame_interval[CSI_SINK_PAD];
ret = v4l2_subdev_call(priv->sensor->sd, sensor,
g_skip_frames, &bad_frames);
if (!ret && bad_frames) {
struct v4l2_fract *fi = &priv->frame_interval;
u32 delay_usec;
/*
......@@ -610,8 +632,8 @@ static int csi_start(struct csi_priv *priv)
* to lose vert/horiz sync.
*/
delay_usec = DIV_ROUND_UP_ULL(
(u64)USEC_PER_SEC * fi->numerator * bad_frames,
fi->denominator);
(u64)USEC_PER_SEC * input_fi->numerator * bad_frames,
input_fi->denominator);
usleep_range(delay_usec, delay_usec + 1000);
}
......@@ -627,8 +649,7 @@ static int csi_start(struct csi_priv *priv)
/* start the frame interval monitor */
if (priv->fim && priv->dest == IPU_CSI_DEST_IDMAC) {
ret = imx_media_fim_set_stream(priv->fim, &priv->frame_interval,
true);
ret = imx_media_fim_set_stream(priv->fim, output_fi, true);
if (ret)
goto idmac_stop;
}
......@@ -643,8 +664,7 @@ static int csi_start(struct csi_priv *priv)
fim_off:
if (priv->fim && priv->dest == IPU_CSI_DEST_IDMAC)
imx_media_fim_set_stream(priv->fim, &priv->frame_interval,
false);
imx_media_fim_set_stream(priv->fim, NULL, false);
idmac_stop:
if (priv->dest == IPU_CSI_DEST_IDMAC)
csi_idmac_stop(priv);
......@@ -658,14 +678,85 @@ static void csi_stop(struct csi_priv *priv)
/* stop the frame interval monitor */
if (priv->fim)
imx_media_fim_set_stream(priv->fim,
&priv->frame_interval,
false);
imx_media_fim_set_stream(priv->fim, NULL, false);
}
ipu_csi_disable(priv->csi);
}
static const struct csi_skip_desc csi_skip[12] = {
{ 1, 1, 0x00 }, /* Keep all frames */
{ 5, 6, 0x10 }, /* Skip every sixth frame */
{ 4, 5, 0x08 }, /* Skip every fifth frame */
{ 3, 4, 0x04 }, /* Skip every fourth frame */
{ 2, 3, 0x02 }, /* Skip every third frame */
{ 3, 5, 0x0a }, /* Skip frames 1 and 3 of every 5 */
{ 1, 2, 0x01 }, /* Skip every second frame */
{ 2, 5, 0x0b }, /* Keep frames 1 and 4 of every 5 */
{ 1, 3, 0x03 }, /* Keep one in three frames */
{ 1, 4, 0x07 }, /* Keep one in four frames */
{ 1, 5, 0x0f }, /* Keep one in five frames */
{ 1, 6, 0x1f }, /* Keep one in six frames */
};
static void csi_apply_skip_interval(const struct csi_skip_desc *skip,
struct v4l2_fract *interval)
{
unsigned int div;
interval->numerator *= skip->max_ratio;
interval->denominator *= skip->keep;
/* Reduce fraction to lowest terms */
div = gcd(interval->numerator, interval->denominator);
if (div > 1) {
interval->numerator /= div;
interval->denominator /= div;
}
}
/*
* Find the skip pattern to produce the output frame interval closest to the
* requested one, for the given input frame interval. Updates the output frame
* interval to the exact value.
*/
static const struct csi_skip_desc *csi_find_best_skip(struct v4l2_fract *in,
struct v4l2_fract *out)
{
const struct csi_skip_desc *skip = &csi_skip[0], *best_skip = skip;
u32 min_err = UINT_MAX;
u64 want_us;
int i;
/* Default to 1:1 ratio */
if (out->numerator == 0 || out->denominator == 0 ||
in->numerator == 0 || in->denominator == 0) {
*out = *in;
return best_skip;
}
want_us = div_u64((u64)USEC_PER_SEC * out->numerator, out->denominator);
/* Find the reduction closest to the requested time per frame */
for (i = 0; i < ARRAY_SIZE(csi_skip); i++, skip++) {
u64 tmp, err;
tmp = div_u64((u64)USEC_PER_SEC * in->numerator *
skip->max_ratio, in->denominator * skip->keep);
err = abs((s64)tmp - want_us);
if (err < min_err) {
min_err = err;
best_skip = skip;
}
}
*out = *in;
csi_apply_skip_interval(best_skip, out);
return best_skip;
}
/*
* V4L2 subdev operations.
*/
......@@ -675,8 +766,13 @@ static int csi_g_frame_interval(struct v4l2_subdev *sd,
{
struct csi_priv *priv = v4l2_get_subdevdata(sd);
if (fi->pad >= CSI_NUM_PADS)
return -EINVAL;
mutex_lock(&priv->lock);
fi->interval = priv->frame_interval;
fi->interval = priv->frame_interval[fi->pad];
mutex_unlock(&priv->lock);
return 0;
......@@ -686,18 +782,44 @@ static int csi_s_frame_interval(struct v4l2_subdev *sd,
struct v4l2_subdev_frame_interval *fi)
{
struct csi_priv *priv = v4l2_get_subdevdata(sd);
struct v4l2_fract *input_fi;
int ret = 0;
mutex_lock(&priv->lock);
/* Output pads mirror active input pad, no limits on input pads */
if (fi->pad == CSI_SRC_PAD_IDMAC || fi->pad == CSI_SRC_PAD_DIRECT)
fi->interval = priv->frame_interval;
input_fi = &priv->frame_interval[CSI_SINK_PAD];
priv->frame_interval = fi->interval;
switch (fi->pad) {
case CSI_SINK_PAD:
/* No limits on input frame interval */
/* Reset output intervals and frame skipping ratio to 1:1 */
priv->frame_interval[CSI_SRC_PAD_IDMAC] = fi->interval;
priv->frame_interval[CSI_SRC_PAD_DIRECT] = fi->interval;
priv->skip = &csi_skip[0];
break;
case CSI_SRC_PAD_IDMAC:
/*
* frame interval at IDMAC output pad depends on input
* interval, modified by frame skipping.
*/
priv->skip = csi_find_best_skip(input_fi, &fi->interval);
break;
case CSI_SRC_PAD_DIRECT:
/*
* frame interval at DIRECT output pad is same as input
* interval.
*/
fi->interval = *input_fi;
break;
default:
ret = -EINVAL;
goto out;
}
priv->frame_interval[fi->pad] = fi->interval;
out:
mutex_unlock(&priv->lock);
return 0;
return ret;
}
static int csi_s_stream(struct v4l2_subdev *sd, int enable)
......@@ -1334,11 +1456,14 @@ static int csi_registered(struct v4l2_subdev *sd)
&priv->cc[i]);
if (ret)
goto put_csi;
/* init default frame interval */
priv->frame_interval[i].numerator = 1;
priv->frame_interval[i].denominator = 30;
}
/* init default frame interval */
priv->frame_interval.numerator = 1;
priv->frame_interval.denominator = 30;
/* disable frame skipping */
priv->skip = &csi_skip[0];
priv->fim = imx_media_fim_init(&priv->sd);
if (IS_ERR(priv->fim)) {
......
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