1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vivid-radio-rx.c - radio receiver support functions.
4 *
5 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6 */
7
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/delay.h>
11 #include <linux/videodev2.h>
12 #include <linux/v4l2-dv-timings.h>
13 #include <linux/sched/signal.h>
14
15 #include <media/v4l2-common.h>
16 #include <media/v4l2-event.h>
17 #include <media/v4l2-dv-timings.h>
18
19 #include "vivid-core.h"
20 #include "vivid-ctrls.h"
21 #include "vivid-radio-common.h"
22 #include "vivid-rds-gen.h"
23 #include "vivid-radio-rx.h"
24
vivid_radio_rx_read(struct file * file,char __user * buf,size_t size,loff_t * offset)25 ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
26 size_t size, loff_t *offset)
27 {
28 struct vivid_dev *dev = video_drvdata(file);
29 struct v4l2_rds_data *data = dev->rds_gen.data;
30 bool use_alternates;
31 ktime_t timestamp;
32 unsigned blk;
33 int perc;
34 int i;
35
36 if (dev->radio_rx_rds_controls)
37 return -EINVAL;
38 if (size < sizeof(*data))
39 return 0;
40 size = sizeof(*data) * (size / sizeof(*data));
41
42 if (mutex_lock_interruptible(&dev->mutex))
43 return -ERESTARTSYS;
44 if (dev->radio_rx_rds_owner &&
45 file->private_data != dev->radio_rx_rds_owner) {
46 mutex_unlock(&dev->mutex);
47 return -EBUSY;
48 }
49 if (dev->radio_rx_rds_owner == NULL) {
50 vivid_radio_rds_init(dev);
51 dev->radio_rx_rds_owner = file->private_data;
52 }
53
54 retry:
55 timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
56 blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
57 use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;
58
59 if (dev->radio_rx_rds_last_block == 0 ||
60 dev->radio_rx_rds_use_alternates != use_alternates) {
61 dev->radio_rx_rds_use_alternates = use_alternates;
62 /* Re-init the RDS generator */
63 vivid_radio_rds_init(dev);
64 }
65 if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
66 dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
67
68 /*
69 * No data is available if there hasn't been time to get new data,
70 * or if the RDS receiver has been disabled, or if we use the data
71 * from the RDS transmitter and that RDS transmitter has been disabled,
72 * or if the signal quality is too weak.
73 */
74 if (blk == dev->radio_rx_rds_last_block || !dev->radio_rx_rds_enabled ||
75 (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) ||
76 abs(dev->radio_rx_sig_qual) > 200) {
77 mutex_unlock(&dev->mutex);
78 if (file->f_flags & O_NONBLOCK)
79 return -EWOULDBLOCK;
80 if (msleep_interruptible(20) && signal_pending(current))
81 return -EINTR;
82 if (mutex_lock_interruptible(&dev->mutex))
83 return -ERESTARTSYS;
84 goto retry;
85 }
86
87 /* abs(dev->radio_rx_sig_qual) <= 200, map that to a 0-50% range */
88 perc = abs(dev->radio_rx_sig_qual) / 4;
89
90 for (i = 0; i < size && blk > dev->radio_rx_rds_last_block;
91 dev->radio_rx_rds_last_block++) {
92 unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
93 struct v4l2_rds_data rds = data[data_blk];
94
95 if (data_blk == 0 && dev->radio_rds_loop)
96 vivid_radio_rds_init(dev);
97 if (perc && prandom_u32_max(100) < perc) {
98 switch (prandom_u32_max(4)) {
99 case 0:
100 rds.block |= V4L2_RDS_BLOCK_CORRECTED;
101 break;
102 case 1:
103 rds.block |= V4L2_RDS_BLOCK_INVALID;
104 break;
105 case 2:
106 rds.block |= V4L2_RDS_BLOCK_ERROR;
107 rds.lsb = prandom_u32_max(256);
108 rds.msb = prandom_u32_max(256);
109 break;
110 case 3: /* Skip block altogether */
111 if (i)
112 continue;
113 /*
114 * Must make sure at least one block is
115 * returned, otherwise the application
116 * might think that end-of-file occurred.
117 */
118 break;
119 }
120 }
121 if (copy_to_user(buf + i, &rds, sizeof(rds))) {
122 i = -EFAULT;
123 break;
124 }
125 i += sizeof(rds);
126 }
127 mutex_unlock(&dev->mutex);
128 return i;
129 }
130
vivid_radio_rx_poll(struct file * file,struct poll_table_struct * wait)131 __poll_t vivid_radio_rx_poll(struct file *file, struct poll_table_struct *wait)
132 {
133 return EPOLLIN | EPOLLRDNORM | v4l2_ctrl_poll(file, wait);
134 }
135
vivid_radio_rx_enum_freq_bands(struct file * file,void * fh,struct v4l2_frequency_band * band)136 int vivid_radio_rx_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
137 {
138 if (band->tuner != 0)
139 return -EINVAL;
140
141 if (band->index >= TOT_BANDS)
142 return -EINVAL;
143
144 *band = vivid_radio_bands[band->index];
145 return 0;
146 }
147
vivid_radio_rx_s_hw_freq_seek(struct file * file,void * fh,const struct v4l2_hw_freq_seek * a)148 int vivid_radio_rx_s_hw_freq_seek(struct file *file, void *fh, const struct v4l2_hw_freq_seek *a)
149 {
150 struct vivid_dev *dev = video_drvdata(file);
151 unsigned low, high;
152 unsigned freq;
153 unsigned spacing;
154 unsigned band;
155
156 if (a->tuner)
157 return -EINVAL;
158 if (a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_BOUNDED)
159 return -EINVAL;
160
161 if (!a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_WRAP)
162 return -EINVAL;
163 if (!a->rangelow ^ !a->rangehigh)
164 return -EINVAL;
165
166 if (file->f_flags & O_NONBLOCK)
167 return -EWOULDBLOCK;
168
169 if (a->rangelow) {
170 for (band = 0; band < TOT_BANDS; band++)
171 if (a->rangelow >= vivid_radio_bands[band].rangelow &&
172 a->rangehigh <= vivid_radio_bands[band].rangehigh)
173 break;
174 if (band == TOT_BANDS)
175 return -EINVAL;
176 if (!dev->radio_rx_hw_seek_prog_lim &&
177 (a->rangelow != vivid_radio_bands[band].rangelow ||
178 a->rangehigh != vivid_radio_bands[band].rangehigh))
179 return -EINVAL;
180 low = a->rangelow;
181 high = a->rangehigh;
182 } else {
183 for (band = 0; band < TOT_BANDS; band++)
184 if (dev->radio_rx_freq >= vivid_radio_bands[band].rangelow &&
185 dev->radio_rx_freq <= vivid_radio_bands[band].rangehigh)
186 break;
187 if (band == TOT_BANDS)
188 return -EINVAL;
189 low = vivid_radio_bands[band].rangelow;
190 high = vivid_radio_bands[band].rangehigh;
191 }
192 spacing = band == BAND_AM ? 1600 : 16000;
193 freq = clamp(dev->radio_rx_freq, low, high);
194
195 if (a->seek_upward) {
196 freq = spacing * (freq / spacing) + spacing;
197 if (freq > high) {
198 if (!a->wrap_around)
199 return -ENODATA;
200 freq = spacing * (low / spacing) + spacing;
201 if (freq >= dev->radio_rx_freq)
202 return -ENODATA;
203 }
204 } else {
205 freq = spacing * ((freq + spacing - 1) / spacing) - spacing;
206 if (freq < low) {
207 if (!a->wrap_around)
208 return -ENODATA;
209 freq = spacing * ((high + spacing - 1) / spacing) - spacing;
210 if (freq <= dev->radio_rx_freq)
211 return -ENODATA;
212 }
213 }
214 return 0;
215 }
216
vivid_radio_rx_g_tuner(struct file * file,void * fh,struct v4l2_tuner * vt)217 int vivid_radio_rx_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
218 {
219 struct vivid_dev *dev = video_drvdata(file);
220 int delta = 800;
221 int sig_qual;
222
223 if (vt->index > 0)
224 return -EINVAL;
225
226 strscpy(vt->name, "AM/FM/SW Receiver", sizeof(vt->name));
227 vt->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
228 V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
229 (dev->radio_rx_rds_controls ?
230 V4L2_TUNER_CAP_RDS_CONTROLS :
231 V4L2_TUNER_CAP_RDS_BLOCK_IO) |
232 (dev->radio_rx_hw_seek_prog_lim ?
233 V4L2_TUNER_CAP_HWSEEK_PROG_LIM : 0);
234 switch (dev->radio_rx_hw_seek_mode) {
235 case VIVID_HW_SEEK_BOUNDED:
236 vt->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;
237 break;
238 case VIVID_HW_SEEK_WRAP:
239 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP;
240 break;
241 case VIVID_HW_SEEK_BOTH:
242 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP |
243 V4L2_TUNER_CAP_HWSEEK_BOUNDED;
244 break;
245 }
246 vt->rangelow = AM_FREQ_RANGE_LOW;
247 vt->rangehigh = FM_FREQ_RANGE_HIGH;
248 sig_qual = dev->radio_rx_sig_qual;
249 vt->signal = abs(sig_qual) > delta ? 0 :
250 0xffff - ((unsigned)abs(sig_qual) * 0xffff) / delta;
251 vt->afc = sig_qual > delta ? 0 : sig_qual;
252 if (abs(sig_qual) > delta)
253 vt->rxsubchans = 0;
254 else if (dev->radio_rx_freq < FM_FREQ_RANGE_LOW || vt->signal < 0x8000)
255 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
256 else if (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_STEREO))
257 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
258 else
259 vt->rxsubchans = V4L2_TUNER_SUB_STEREO;
260 if (dev->radio_rx_rds_enabled &&
261 (!dev->radio_rds_loop || (dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) &&
262 dev->radio_rx_freq >= FM_FREQ_RANGE_LOW && vt->signal >= 0xc000)
263 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
264 if (dev->radio_rx_rds_controls)
265 vivid_radio_rds_init(dev);
266 vt->audmode = dev->radio_rx_audmode;
267 return 0;
268 }
269
vivid_radio_rx_s_tuner(struct file * file,void * fh,const struct v4l2_tuner * vt)270 int vivid_radio_rx_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
271 {
272 struct vivid_dev *dev = video_drvdata(file);
273
274 if (vt->index)
275 return -EINVAL;
276 dev->radio_rx_audmode = vt->audmode >= V4L2_TUNER_MODE_STEREO;
277 return 0;
278 }
279