// SPDX-License-Identifier: GPL-2.0-only
/*
* vivid-kthread-touch.c - touch capture thread support functions.
*
*/
#include <linux/freezer.h>
#include <linux/jiffies.h>
#include "vivid-core.h"
#include "vivid-kthread-touch.h"
#include "vivid-touch-cap.h"
static noinline_for_stack void vivid_thread_tch_cap_tick(struct vivid_dev *dev,
int dropped_bufs)
{
struct vivid_buffer *tch_cap_buf = NULL;
spin_lock(&dev->slock);
if (!list_empty(&dev->touch_cap_active)) {
tch_cap_buf = list_entry(dev->touch_cap_active.next,
struct vivid_buffer, list);
list_del(&tch_cap_buf->list);
}
spin_unlock(&dev->slock);
if (tch_cap_buf) {
v4l2_ctrl_request_setup(tch_cap_buf->vb.vb2_buf.req_obj.req,
&dev->ctrl_hdl_touch_cap);
vivid_fillbuff_tch(dev, tch_cap_buf);
v4l2_ctrl_request_complete(tch_cap_buf->vb.vb2_buf.req_obj.req,
&dev->ctrl_hdl_touch_cap);
vb2_buffer_done(&tch_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
dprintk(dev, 2, "touch_cap buffer %d done\n",
tch_cap_buf->vb.vb2_buf.index);
tch_cap_buf->vb.vb2_buf.timestamp = ktime_get_ns() + dev->time_wrap_offset;
}
dev->dqbuf_error = false;
}
static int vivid_thread_touch_cap(void *data)
{
struct vivid_dev *dev = data;
u64 numerators_since_start;
u64 buffers_since_start;
u64 next_jiffies_since_start;
unsigned long jiffies_since_start;
unsigned long cur_jiffies;
unsigned int wait_jiffies;
unsigned int numerator;
unsigned int denominator;
int dropped_bufs;
dprintk(dev, 1, "Touch Capture Thread Start\n");
set_freezable();
/* Resets frame counters */
dev->touch_cap_seq_offset = 0;
dev->touch_cap_seq_count = 0;
dev->touch_cap_seq_resync = false;
dev->jiffies_touch_cap = jiffies;
if (dev->time_wrap)
dev->time_wrap_offset = dev->time_wrap - ktime_get_ns();
else
dev->time_wrap_offset = 0;
for (;;) {
try_to_freeze();
if (kthread_should_stop())
break;
if (!mutex_trylock(&dev->mutex)) {
schedule();
continue;
}
cur_jiffies = jiffies;
if (dev->touch_cap_seq_resync) {
dev->jiffies_touch_cap = cur_jiffies;
dev->touch_cap_seq_offset = dev->touch_cap_seq_count + 1;
dev->touch_cap_seq_count = 0;
dev->cap_seq_resync = false;
}
denominator = dev->timeperframe_tch_cap.denominator;
numerator = dev->timeperframe_tch_cap.numerator;
/* Calculate the number of jiffies since we started streaming */
jiffies_since_start = cur_jiffies - dev->jiffies_touch_cap;
/* Get the number of buffers streamed since the start */
buffers_since_start = (u64)jiffies_since_start * denominator +
(HZ * numerator) / 2;
do_div(buffers_since_start, HZ * numerator);
/*
* After more than 0xf0000000 (rounded down to a multiple of
* 'jiffies-per-day' to ease jiffies_to_msecs calculation)
* jiffies have passed since we started streaming reset the
* counters and keep track of the sequence offset.
*/
if (jiffies_since_start > JIFFIES_RESYNC) {
dev->jiffies_touch_cap = cur_jiffies;
dev->cap_seq_offset = buffers_since_start;
buffers_since_start = 0;
}
dropped_bufs = buffers_since_start + dev->touch_cap_seq_offset - dev->touch_cap_seq_count;
dev->touch_cap_seq_count = buffers_since_start + dev->touch_cap_seq_offset;
dev->touch_cap_with_seq_wrap_count =
dev->touch_cap_seq_count - dev->touch_cap_seq_start;
vivid_thread_tch_cap_tick(dev, dropped_bufs);
/*
* Calculate the number of 'numerators' streamed
* since we started, including the current buffer.
*/
numerators_since_start = ++buffers_since_start * numerator;
/* And the number of jiffies since we started */
jiffies_since_start = jiffies - dev->jiffies_touch_cap;
mutex_unlock(&dev->mutex);
/*
* Calculate when that next buffer is supposed to start
* in jiffies since we started streaming.
*/
next_jiffies_since_start = numerators_since_start * HZ +
denominator / 2;
do_div(next_jiffies_since_start, denominator);
/* If it is in the past, then just schedule asap */
if (next_jiffies_since_start < jiffies_since_start)
next_jiffies_since_start = jiffies_since_start;
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
!kthread_should_stop())
schedule();
}
dprintk(dev, 1, "Touch Capture Thread End\n");
return 0;
}
int vivid_start_generating_touch_cap(struct vivid_dev *dev)
{
if (dev->kthread_touch_cap) {
dev->touch_cap_streaming = true;
return 0;
}
dev->touch_cap_seq_start = dev->seq_wrap * 128;
dev->kthread_touch_cap = kthread_run(vivid_thread_touch_cap, dev,
"%s-tch-cap", dev->v4l2_dev.name);
if (IS_ERR(dev->kthread_touch_cap)) {
int err = PTR_ERR(dev->kthread_touch_cap);
dev->kthread_touch_cap = NULL;
v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
return err;
}
dev->touch_cap_streaming = true;
dprintk(dev, 1, "returning from %s\n", __func__);
return 0;
}
void vivid_stop_generating_touch_cap(struct vivid_dev *dev)
{
if (!dev->kthread_touch_cap)
return;
dev->touch_cap_streaming = false;
while (!list_empty(&dev->touch_cap_active)) {
struct vivid_buffer *buf;
buf = list_entry(dev->touch_cap_active.next,
struct vivid_buffer, list);
list_del(&buf->list);
v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
&dev->ctrl_hdl_touch_cap);
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
dprintk(dev, 2, "touch_cap buffer %d done\n",
buf->vb.vb2_buf.index);
}
kthread_stop(dev->kthread_touch_cap);
dev->kthread_touch_cap = NULL;
}
Codebase Browser
linux