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 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 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 } 145 146 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 } 168 169 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