// SPDX-License-Identifier: GPL-2.0+
/*
* Frame Interval Monitor.
*
* Copyright (c) 2016 Mentor Graphics Inc.
*/
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-subdev.h>
#include <media/imx.h>
#include "imx-media.h"
enum {
FIM_CL_ENABLE = 0,
FIM_CL_NUM,
FIM_CL_TOLERANCE_MIN,
FIM_CL_TOLERANCE_MAX,
FIM_CL_NUM_SKIP,
FIM_NUM_CONTROLS,
};
enum {
FIM_CL_ICAP_EDGE = 0,
FIM_CL_ICAP_CHANNEL,
FIM_NUM_ICAP_CONTROLS,
};
#define FIM_CL_ENABLE_DEF 0 /* FIM disabled by default */
#define FIM_CL_NUM_DEF 8 /* average 8 frames */
#define FIM_CL_NUM_SKIP_DEF 2 /* skip 2 frames after restart */
#define FIM_CL_TOLERANCE_MIN_DEF 50 /* usec */
#define FIM_CL_TOLERANCE_MAX_DEF 0 /* no max tolerance (unbounded) */
struct imx_media_fim {
/* the owning subdev of this fim instance */
struct v4l2_subdev *sd;
/* FIM's control handler */
struct v4l2_ctrl_handler ctrl_handler;
/* control clusters */
struct v4l2_ctrl *ctrl[FIM_NUM_CONTROLS];
struct v4l2_ctrl *icap_ctrl[FIM_NUM_ICAP_CONTROLS];
spinlock_t lock; /* protect control values */
/* current control values */
bool enabled;
int num_avg;
int num_skip;
unsigned long tolerance_min; /* usec */
unsigned long tolerance_max; /* usec */
/* input capture method of measuring FI */
int icap_channel;
int icap_flags;
int counter;
ktime_t last_ts;
unsigned long sum; /* usec */
unsigned long nominal; /* usec */
struct completion icap_first_event;
bool stream_on;
};
static bool icap_enabled(struct imx_media_fim *fim)
{
return fim->icap_flags != IRQ_TYPE_NONE;
}
static void update_fim_nominal(struct imx_media_fim *fim,
const struct v4l2_fract *fi)
{
if (fi->denominator == 0) {
dev_dbg(fim->sd->dev, "no frame interval, FIM disabled\n");
fim->enabled = false;
return;
}
fim->nominal = DIV_ROUND_CLOSEST_ULL(1000000ULL * (u64)fi->numerator,
fi->denominator);
dev_dbg(fim->sd->dev, "FI=%lu usec\n", fim->nominal);
}
static void reset_fim(struct imx_media_fim *fim, bool curval)
{
struct v4l2_ctrl *icap_chan = fim->icap_ctrl[FIM_CL_ICAP_CHANNEL];
struct v4l2_ctrl *icap_edge = fim->icap_ctrl[FIM_CL_ICAP_EDGE];
struct v4l2_ctrl *en = fim->ctrl[FIM_CL_ENABLE];
struct v4l2_ctrl *num = fim->ctrl[FIM_CL_NUM];
struct v4l2_ctrl *skip = fim->ctrl[FIM_CL_NUM_SKIP];
struct v4l2_ctrl *tol_min = fim->ctrl[FIM_CL_TOLERANCE_MIN];
struct v4l2_ctrl *tol_max = fim->ctrl[FIM_CL_TOLERANCE_MAX];
if (curval) {
fim->enabled = en->cur.val;
fim->icap_flags = icap_edge->cur.val;
fim->icap_channel = icap_chan->cur.val;
fim->num_avg = num->cur.val;
fim->num_skip = skip->cur.val;
fim->tolerance_min = tol_min->cur.val;
fim->tolerance_max = tol_max->cur.val;
} else {
fim->enabled = en->val;
fim->icap_flags = icap_edge->val;
fim->icap_channel = icap_chan->val;
fim->num_avg = num->val;
fim->num_skip = skip->val;
fim->tolerance_min = tol_min->val;
fim->tolerance_max = tol_max->val;
}
/* disable tolerance range if max <= min */
if (fim->tolerance_max <= fim->tolerance_min)
fim->tolerance_max = 0;
/* num_skip must be >= 1 if input capture not used */
if (!icap_enabled(fim))
fim->num_skip = max_t(int, fim->num_skip, 1);
fim->counter = -fim->num_skip;
fim->sum = 0;
}
static void send_fim_event(struct imx_media_fim *fim, unsigned long error)
{
static const struct v4l2_event ev = {
.type = V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR,
};
v4l2_subdev_notify_event(fim->sd, &ev);
}
/*
* Monitor an averaged frame interval. If the average deviates too much
* from the nominal frame rate, send the frame interval error event. The
* frame intervals are averaged in order to quiet noise from
* (presumably random) interrupt latency.
*/
static void frame_interval_monitor(struct imx_media_fim *fim,
ktime_t timestamp)
{
long long interval, error;
unsigned long error_avg;
bool send_event = false;
if (!fim->enabled || ++fim->counter <= 0)
goto out_update_ts;
/* max error is less than l00µs, so use 32-bit division or fail */
interval = ktime_to_ns(ktime_sub(timestamp, fim->last_ts));
error = abs(interval - NSEC_PER_USEC * (u64)fim->nominal);
if (error > U32_MAX)
error = U32_MAX;
else
error = abs((u32)error / NSEC_PER_USEC);
if (fim->tolerance_max && error >= fim->tolerance_max) {
dev_dbg(fim->sd->dev,
"FIM: %llu ignored, out of tolerance bounds\n",
error);
fim->counter--;
goto out_update_ts;
}
fim->sum += error;
if (fim->counter == fim->num_avg) {
error_avg = DIV_ROUND_CLOSEST(fim->sum, fim->num_avg);
if (error_avg > fim->tolerance_min)
send_event = true;
dev_dbg(fim->sd->dev, "FIM: error: %lu usec%s\n",
error_avg, send_event ? " (!!!)" : "");
fim->counter = 0;
fim->sum = 0;
}
out_update_ts:
fim->last_ts = timestamp;
if (send_event)
send_fim_event(fim, error_avg);
}
/*
* In case we are monitoring the first frame interval after streamon
* (when fim->num_skip = 0), we need a valid fim->last_ts before we
* can begin. This only applies to the input capture method. It is not
* possible to accurately measure the first FI after streamon using the
* EOF method, so fim->num_skip minimum is set to 1 in that case, so this
* function is a noop when the EOF method is used.
*/
static void fim_acquire_first_ts(struct imx_media_fim *fim)
{
unsigned long ret;
if (!fim->enabled || fim->num_skip > 0)
return;
ret = wait_for_completion_timeout(
&fim->icap_first_event,
msecs_to_jiffies(IMX_MEDIA_EOF_TIMEOUT));
if (ret == 0)
v4l2_warn(fim->sd, "wait first icap event timeout\n");
}
/* FIM Controls */
static int fim_s_ctrl(struct v4l2_ctrl *ctrl)
{
struct imx_media_fim *fim = container_of(ctrl->handler,
struct imx_media_fim,
ctrl_handler);
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&fim->lock, flags);
switch (ctrl->id) {
case V4L2_CID_IMX_FIM_ENABLE:
break;
case V4L2_CID_IMX_FIM_ICAP_EDGE:
if (fim->stream_on)
ret = -EBUSY;
break;
default:
ret = -EINVAL;
}
if (!ret)
reset_fim(fim, false);
spin_unlock_irqrestore(&fim->lock, flags);
return ret;
}
static const struct v4l2_ctrl_ops fim_ctrl_ops = {
.s_ctrl = fim_s_ctrl,
};
static const struct v4l2_ctrl_config fim_ctrl[] = {
[FIM_CL_ENABLE] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_ENABLE,
.name = "FIM Enable",
.type = V4L2_CTRL_TYPE_BOOLEAN,
.def = FIM_CL_ENABLE_DEF,
.min = 0,
.max = 1,
.step = 1,
},
[FIM_CL_NUM] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_NUM,
.name = "FIM Num Average",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = FIM_CL_NUM_DEF,
.min = 1, /* no averaging */
.max = 64, /* average 64 frames */
.step = 1,
},
[FIM_CL_TOLERANCE_MIN] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_TOLERANCE_MIN,
.name = "FIM Tolerance Min",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = FIM_CL_TOLERANCE_MIN_DEF,
.min = 2,
.max = 200,
.step = 1,
},
[FIM_CL_TOLERANCE_MAX] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_TOLERANCE_MAX,
.name = "FIM Tolerance Max",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = FIM_CL_TOLERANCE_MAX_DEF,
.min = 0,
.max = 500,
.step = 1,
},
[FIM_CL_NUM_SKIP] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_NUM_SKIP,
.name = "FIM Num Skip",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = FIM_CL_NUM_SKIP_DEF,
.min = 0, /* skip no frames */
.max = 256, /* skip 256 frames */
.step = 1,
},
};
static const struct v4l2_ctrl_config fim_icap_ctrl[] = {
[FIM_CL_ICAP_EDGE] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_ICAP_EDGE,
.name = "FIM Input Capture Edge",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = IRQ_TYPE_NONE, /* input capture disabled by default */
.min = IRQ_TYPE_NONE,
.max = IRQ_TYPE_EDGE_BOTH,
.step = 1,
},
[FIM_CL_ICAP_CHANNEL] = {
.ops = &fim_ctrl_ops,
.id = V4L2_CID_IMX_FIM_ICAP_CHANNEL,
.name = "FIM Input Capture Channel",
.type = V4L2_CTRL_TYPE_INTEGER,
.def = 0,
.min = 0,
.max = 1,
.step = 1,
},
};
static int init_fim_controls(struct imx_media_fim *fim)
{
struct v4l2_ctrl_handler *hdlr = &fim->ctrl_handler;
int i, ret;
v4l2_ctrl_handler_init(hdlr, FIM_NUM_CONTROLS + FIM_NUM_ICAP_CONTROLS);
for (i = 0; i < FIM_NUM_CONTROLS; i++)
fim->ctrl[i] = v4l2_ctrl_new_custom(hdlr,
&fim_ctrl[i],
NULL);
for (i = 0; i < FIM_NUM_ICAP_CONTROLS; i++)
fim->icap_ctrl[i] = v4l2_ctrl_new_custom(hdlr,
&fim_icap_ctrl[i],
NULL);
if (hdlr->error) {
ret = hdlr->error;
goto err_free;
}
v4l2_ctrl_cluster(FIM_NUM_CONTROLS, fim->ctrl);
v4l2_ctrl_cluster(FIM_NUM_ICAP_CONTROLS, fim->icap_ctrl);
return 0;
err_free:
v4l2_ctrl_handler_free(hdlr);
return ret;
}
/*
* Monitor frame intervals via EOF interrupt. This method is
* subject to uncertainty errors introduced by interrupt latency.
*
* This is a noop if the Input Capture method is being used, since
* the frame_interval_monitor() is called by the input capture event
* callback handler in that case.
*/
void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp)
{
unsigned long flags;
spin_lock_irqsave(&fim->lock, flags);
if (!icap_enabled(fim))
frame_interval_monitor(fim, timestamp);
spin_unlock_irqrestore(&fim->lock, flags);
}
/* Called by the subdev in its s_stream callback */
void imx_media_fim_set_stream(struct imx_media_fim *fim,
const struct v4l2_fract *fi,
bool on)
{
unsigned long flags;
v4l2_ctrl_lock(fim->ctrl[FIM_CL_ENABLE]);
if (fim->stream_on == on)
goto out;
if (on) {
spin_lock_irqsave(&fim->lock, flags);
reset_fim(fim, true);
update_fim_nominal(fim, fi);
spin_unlock_irqrestore(&fim->lock, flags);
if (icap_enabled(fim))
fim_acquire_first_ts(fim);
}
fim->stream_on = on;
out:
v4l2_ctrl_unlock(fim->ctrl[FIM_CL_ENABLE]);
}
int imx_media_fim_add_controls(struct imx_media_fim *fim)
{
/* add the FIM controls to the calling subdev ctrl handler */
return v4l2_ctrl_add_handler(fim->sd->ctrl_handler,
&fim->ctrl_handler, NULL, true);
}
/* Called by the subdev in its subdev registered callback */
struct imx_media_fim *imx_media_fim_init(struct v4l2_subdev *sd)
{
struct imx_media_fim *fim;
int ret;
fim = devm_kzalloc(sd->dev, sizeof(*fim), GFP_KERNEL);
if (!fim)
return ERR_PTR(-ENOMEM);
fim->sd = sd;
spin_lock_init(&fim->lock);
ret = init_fim_controls(fim);
if (ret)
return ERR_PTR(ret);
return fim;
}
void imx_media_fim_free(struct imx_media_fim *fim)
{
v4l2_ctrl_handler_free(&fim->ctrl_handler);
}
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