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 <linux/jiffies.h>
9 #include "vivid-core.h"
10 #include "vivid-kthread-touch.h"
11 #include "vivid-touch-cap.h"
12
vivid_thread_tch_cap_tick(struct vivid_dev * dev,int dropped_bufs)13 static noinline_for_stack void vivid_thread_tch_cap_tick(struct vivid_dev *dev,
14 int dropped_bufs)
15 {
16 struct vivid_buffer *tch_cap_buf = NULL;
17
18 spin_lock(&dev->slock);
19 if (!list_empty(&dev->touch_cap_active)) {
20 tch_cap_buf = list_entry(dev->touch_cap_active.next,
21 struct vivid_buffer, list);
22 list_del(&tch_cap_buf->list);
23 }
24
25 spin_unlock(&dev->slock);
26
27 if (tch_cap_buf) {
28 v4l2_ctrl_request_setup(tch_cap_buf->vb.vb2_buf.req_obj.req,
29 &dev->ctrl_hdl_touch_cap);
30
31 vivid_fillbuff_tch(dev, tch_cap_buf);
32 v4l2_ctrl_request_complete(tch_cap_buf->vb.vb2_buf.req_obj.req,
33 &dev->ctrl_hdl_touch_cap);
34 vb2_buffer_done(&tch_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
35 VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
36 dprintk(dev, 2, "touch_cap buffer %d done\n",
37 tch_cap_buf->vb.vb2_buf.index);
38
39 tch_cap_buf->vb.vb2_buf.timestamp = ktime_get_ns() + dev->time_wrap_offset;
40 }
41 dev->dqbuf_error = false;
42 }
43
vivid_thread_touch_cap(void * data)44 static int vivid_thread_touch_cap(void *data)
45 {
46 struct vivid_dev *dev = data;
47 u64 numerators_since_start;
48 u64 buffers_since_start;
49 u64 next_jiffies_since_start;
50 unsigned long jiffies_since_start;
51 unsigned long cur_jiffies;
52 unsigned int wait_jiffies;
53 unsigned int numerator;
54 unsigned int denominator;
55 int dropped_bufs;
56
57 dprintk(dev, 1, "Touch Capture Thread Start\n");
58
59 set_freezable();
60
61 /* Resets frame counters */
62 dev->touch_cap_seq_offset = 0;
63 dev->touch_cap_seq_count = 0;
64 dev->touch_cap_seq_resync = false;
65 dev->jiffies_touch_cap = jiffies;
66 if (dev->time_wrap)
67 dev->time_wrap_offset = dev->time_wrap - ktime_get_ns();
68 else
69 dev->time_wrap_offset = 0;
70
71 for (;;) {
72 try_to_freeze();
73 if (kthread_should_stop())
74 break;
75
76 if (!mutex_trylock(&dev->mutex)) {
77 schedule();
78 continue;
79 }
80 cur_jiffies = jiffies;
81 if (dev->touch_cap_seq_resync) {
82 dev->jiffies_touch_cap = cur_jiffies;
83 dev->touch_cap_seq_offset = dev->touch_cap_seq_count + 1;
84 dev->touch_cap_seq_count = 0;
85 dev->cap_seq_resync = false;
86 }
87 denominator = dev->timeperframe_tch_cap.denominator;
88 numerator = dev->timeperframe_tch_cap.numerator;
89
90 /* Calculate the number of jiffies since we started streaming */
91 jiffies_since_start = cur_jiffies - dev->jiffies_touch_cap;
92 /* Get the number of buffers streamed since the start */
93 buffers_since_start = (u64)jiffies_since_start * denominator +
94 (HZ * numerator) / 2;
95 do_div(buffers_since_start, HZ * numerator);
96
97 /*
98 * After more than 0xf0000000 (rounded down to a multiple of
99 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
100 * jiffies have passed since we started streaming reset the
101 * counters and keep track of the sequence offset.
102 */
103 if (jiffies_since_start > JIFFIES_RESYNC) {
104 dev->jiffies_touch_cap = cur_jiffies;
105 dev->cap_seq_offset = buffers_since_start;
106 buffers_since_start = 0;
107 }
108 dropped_bufs = buffers_since_start + dev->touch_cap_seq_offset - dev->touch_cap_seq_count;
109 dev->touch_cap_seq_count = buffers_since_start + dev->touch_cap_seq_offset;
110 dev->touch_cap_with_seq_wrap_count =
111 dev->touch_cap_seq_count - dev->touch_cap_seq_start;
112
113 vivid_thread_tch_cap_tick(dev, dropped_bufs);
114
115 /*
116 * Calculate the number of 'numerators' streamed
117 * since we started, including the current buffer.
118 */
119 numerators_since_start = ++buffers_since_start * numerator;
120
121 /* And the number of jiffies since we started */
122 jiffies_since_start = jiffies - dev->jiffies_touch_cap;
123
124 mutex_unlock(&dev->mutex);
125
126 /*
127 * Calculate when that next buffer is supposed to start
128 * in jiffies since we started streaming.
129 */
130 next_jiffies_since_start = numerators_since_start * HZ +
131 denominator / 2;
132 do_div(next_jiffies_since_start, denominator);
133 /* If it is in the past, then just schedule asap */
134 if (next_jiffies_since_start < jiffies_since_start)
135 next_jiffies_since_start = jiffies_since_start;
136
137 wait_jiffies = next_jiffies_since_start - jiffies_since_start;
138 while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
139 !kthread_should_stop())
140 schedule();
141 }
142 dprintk(dev, 1, "Touch Capture Thread End\n");
143 return 0;
144 }
145
vivid_start_generating_touch_cap(struct vivid_dev * dev)146 int vivid_start_generating_touch_cap(struct vivid_dev *dev)
147 {
148 if (dev->kthread_touch_cap) {
149 dev->touch_cap_streaming = true;
150 return 0;
151 }
152
153 dev->touch_cap_seq_start = dev->seq_wrap * 128;
154 dev->kthread_touch_cap = kthread_run(vivid_thread_touch_cap, dev,
155 "%s-tch-cap", dev->v4l2_dev.name);
156
157 if (IS_ERR(dev->kthread_touch_cap)) {
158 int err = PTR_ERR(dev->kthread_touch_cap);
159
160 dev->kthread_touch_cap = NULL;
161 v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
162 return err;
163 }
164 dev->touch_cap_streaming = true;
165 dprintk(dev, 1, "returning from %s\n", __func__);
166 return 0;
167 }
168
vivid_stop_generating_touch_cap(struct vivid_dev * dev)169 void vivid_stop_generating_touch_cap(struct vivid_dev *dev)
170 {
171 if (!dev->kthread_touch_cap)
172 return;
173
174 dev->touch_cap_streaming = false;
175
176 while (!list_empty(&dev->touch_cap_active)) {
177 struct vivid_buffer *buf;
178
179 buf = list_entry(dev->touch_cap_active.next,
180 struct vivid_buffer, list);
181 list_del(&buf->list);
182 v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
183 &dev->ctrl_hdl_touch_cap);
184 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
185 dprintk(dev, 2, "touch_cap buffer %d done\n",
186 buf->vb.vb2_buf.index);
187 }
188
189 kthread_stop(dev->kthread_touch_cap);
190 dev->kthread_touch_cap = NULL;
191 }
192