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 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 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 } 138 139 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 } 160 161 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