1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vivid-kthread-touch.c - touch capture thread support functions.
4 *
5 */
6
7 #include <linux/freezer.h>
8 #include "vivid-core.h"
9 #include "vivid-kthread-touch.h"
10 #include "vivid-touch-cap.h"
11
vivid_thread_tch_cap_tick(struct vivid_dev * dev,int dropped_bufs)12 static noinline_for_stack void vivid_thread_tch_cap_tick(struct vivid_dev *dev,
13 int dropped_bufs)
14 {
15 struct vivid_buffer *tch_cap_buf = NULL;
16
17 spin_lock(&dev->slock);
18 if (!list_empty(&dev->touch_cap_active)) {
19 tch_cap_buf = list_entry(dev->touch_cap_active.next,
20 struct vivid_buffer, list);
21 list_del(&tch_cap_buf->list);
22 }
23
24 spin_unlock(&dev->slock);
25
26 if (tch_cap_buf) {
27 v4l2_ctrl_request_setup(tch_cap_buf->vb.vb2_buf.req_obj.req,
28 &dev->ctrl_hdl_touch_cap);
29
30 vivid_fillbuff_tch(dev, tch_cap_buf);
31 v4l2_ctrl_request_complete(tch_cap_buf->vb.vb2_buf.req_obj.req,
32 &dev->ctrl_hdl_touch_cap);
33 vb2_buffer_done(&tch_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
34 VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
35 dprintk(dev, 2, "touch_cap buffer %d done\n",
36 tch_cap_buf->vb.vb2_buf.index);
37
38 tch_cap_buf->vb.vb2_buf.timestamp = ktime_get_ns() + dev->time_wrap_offset;
39 }
40 dev->dqbuf_error = false;
41 }
42
vivid_thread_touch_cap(void * data)43 static int vivid_thread_touch_cap(void *data)
44 {
45 struct vivid_dev *dev = data;
46 u64 numerators_since_start;
47 u64 buffers_since_start;
48 u64 next_jiffies_since_start;
49 unsigned long jiffies_since_start;
50 unsigned long cur_jiffies;
51 unsigned int wait_jiffies;
52 unsigned int numerator;
53 unsigned int denominator;
54 int dropped_bufs;
55
56 dprintk(dev, 1, "Touch Capture Thread Start\n");
57
58 set_freezable();
59
60 /* Resets frame counters */
61 dev->touch_cap_seq_offset = 0;
62 dev->touch_cap_seq_count = 0;
63 dev->touch_cap_seq_resync = false;
64 dev->jiffies_touch_cap = jiffies;
65
66 for (;;) {
67 try_to_freeze();
68 if (kthread_should_stop())
69 break;
70
71 if (!mutex_trylock(&dev->mutex)) {
72 schedule();
73 continue;
74 }
75 cur_jiffies = jiffies;
76 if (dev->touch_cap_seq_resync) {
77 dev->jiffies_touch_cap = cur_jiffies;
78 dev->touch_cap_seq_offset = dev->touch_cap_seq_count + 1;
79 dev->touch_cap_seq_count = 0;
80 dev->cap_seq_resync = false;
81 }
82 denominator = dev->timeperframe_tch_cap.denominator;
83 numerator = dev->timeperframe_tch_cap.numerator;
84
85 /* Calculate the number of jiffies since we started streaming */
86 jiffies_since_start = cur_jiffies - dev->jiffies_touch_cap;
87 /* Get the number of buffers streamed since the start */
88 buffers_since_start = (u64)jiffies_since_start * denominator +
89 (HZ * numerator) / 2;
90 do_div(buffers_since_start, HZ * numerator);
91
92 /*
93 * After more than 0xf0000000 (rounded down to a multiple of
94 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
95 * jiffies have passed since we started streaming reset the
96 * counters and keep track of the sequence offset.
97 */
98 if (jiffies_since_start > JIFFIES_RESYNC) {
99 dev->jiffies_touch_cap = cur_jiffies;
100 dev->cap_seq_offset = buffers_since_start;
101 buffers_since_start = 0;
102 }
103 dropped_bufs = buffers_since_start + dev->touch_cap_seq_offset - dev->touch_cap_seq_count;
104 dev->touch_cap_seq_count = buffers_since_start + dev->touch_cap_seq_offset;
105
106 vivid_thread_tch_cap_tick(dev, dropped_bufs);
107
108 /*
109 * Calculate the number of 'numerators' streamed
110 * since we started, including the current buffer.
111 */
112 numerators_since_start = ++buffers_since_start * numerator;
113
114 /* And the number of jiffies since we started */
115 jiffies_since_start = jiffies - dev->jiffies_touch_cap;
116
117 mutex_unlock(&dev->mutex);
118
119 /*
120 * Calculate when that next buffer is supposed to start
121 * in jiffies since we started streaming.
122 */
123 next_jiffies_since_start = numerators_since_start * HZ +
124 denominator / 2;
125 do_div(next_jiffies_since_start, denominator);
126 /* If it is in the past, then just schedule asap */
127 if (next_jiffies_since_start < jiffies_since_start)
128 next_jiffies_since_start = jiffies_since_start;
129
130 wait_jiffies = next_jiffies_since_start - jiffies_since_start;
131 while (jiffies - cur_jiffies < wait_jiffies &&
132 !kthread_should_stop())
133 schedule();
134 }
135 dprintk(dev, 1, "Touch Capture Thread End\n");
136 return 0;
137 }
138
vivid_start_generating_touch_cap(struct vivid_dev * dev)139 int vivid_start_generating_touch_cap(struct vivid_dev *dev)
140 {
141 if (dev->kthread_touch_cap) {
142 dev->touch_cap_streaming = true;
143 return 0;
144 }
145
146 dev->kthread_touch_cap = kthread_run(vivid_thread_touch_cap, dev,
147 "%s-tch-cap", dev->v4l2_dev.name);
148
149 if (IS_ERR(dev->kthread_touch_cap)) {
150 int err = PTR_ERR(dev->kthread_touch_cap);
151
152 dev->kthread_touch_cap = NULL;
153 v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
154 return err;
155 }
156 dev->touch_cap_streaming = true;
157 dprintk(dev, 1, "returning from %s\n", __func__);
158 return 0;
159 }
160
vivid_stop_generating_touch_cap(struct vivid_dev * dev)161 void vivid_stop_generating_touch_cap(struct vivid_dev *dev)
162 {
163 if (!dev->kthread_touch_cap)
164 return;
165
166 dev->touch_cap_streaming = false;
167
168 while (!list_empty(&dev->touch_cap_active)) {
169 struct vivid_buffer *buf;
170
171 buf = list_entry(dev->touch_cap_active.next,
172 struct vivid_buffer, list);
173 list_del(&buf->list);
174 v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
175 &dev->ctrl_hdl_touch_cap);
176 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
177 dprintk(dev, 2, "touch_cap buffer %d done\n",
178 buf->vb.vb2_buf.index);
179 }
180
181 kthread_stop(dev->kthread_touch_cap);
182 dev->kthread_touch_cap = NULL;
183 }
184