1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * vivid-radio-common.c - common radio rx/tx 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
13#include "vivid-core.h"
14#include "vivid-ctrls.h"
15#include "vivid-radio-common.h"
16#include "vivid-rds-gen.h"
17
18/*
19 * These functions are shared between the vivid receiver and transmitter
20 * since both use the same frequency bands.
21 */
22
23const struct v4l2_frequency_band vivid_radio_bands[TOT_BANDS] = {
24 /* Band FM */
25 {
26 .type = V4L2_TUNER_RADIO,
27 .index = 0,
28 .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
29 V4L2_TUNER_CAP_FREQ_BANDS,
30 .rangelow = FM_FREQ_RANGE_LOW,
31 .rangehigh = FM_FREQ_RANGE_HIGH,
32 .modulation = V4L2_BAND_MODULATION_FM,
33 },
34 /* Band AM */
35 {
36 .type = V4L2_TUNER_RADIO,
37 .index = 1,
38 .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
39 .rangelow = AM_FREQ_RANGE_LOW,
40 .rangehigh = AM_FREQ_RANGE_HIGH,
41 .modulation = V4L2_BAND_MODULATION_AM,
42 },
43 /* Band SW */
44 {
45 .type = V4L2_TUNER_RADIO,
46 .index = 2,
47 .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
48 .rangelow = SW_FREQ_RANGE_LOW,
49 .rangehigh = SW_FREQ_RANGE_HIGH,
50 .modulation = V4L2_BAND_MODULATION_AM,
51 },
52};
53
54/*
55 * Initialize the RDS generator. If we can loop, then the RDS generator
56 * is set up with the values from the RDS TX controls, otherwise it
57 * will fill in standard values using one of two alternates.
58 */
59void vivid_radio_rds_init(struct vivid_dev *dev)
60{
61 struct vivid_rds_gen *rds = &dev->rds_gen;
62 bool alt = dev->radio_rx_rds_use_alternates;
63
64 /* Do nothing, blocks will be filled by the transmitter */
65 if (dev->radio_rds_loop && !dev->radio_tx_rds_controls)
66 return;
67
68 if (dev->radio_rds_loop) {
69 v4l2_ctrl_lock(ctrl: dev->radio_tx_rds_pi);
70 rds->picode = dev->radio_tx_rds_pi->cur.val;
71 rds->pty = dev->radio_tx_rds_pty->cur.val;
72 rds->mono_stereo = dev->radio_tx_rds_mono_stereo->cur.val;
73 rds->art_head = dev->radio_tx_rds_art_head->cur.val;
74 rds->compressed = dev->radio_tx_rds_compressed->cur.val;
75 rds->dyn_pty = dev->radio_tx_rds_dyn_pty->cur.val;
76 rds->ta = dev->radio_tx_rds_ta->cur.val;
77 rds->tp = dev->radio_tx_rds_tp->cur.val;
78 rds->ms = dev->radio_tx_rds_ms->cur.val;
79 strscpy(rds->psname,
80 dev->radio_tx_rds_psname->p_cur.p_char,
81 sizeof(rds->psname));
82 strscpy(rds->radiotext,
83 dev->radio_tx_rds_radiotext->p_cur.p_char + alt * 64,
84 sizeof(rds->radiotext));
85 v4l2_ctrl_unlock(ctrl: dev->radio_tx_rds_pi);
86 } else {
87 vivid_rds_gen_fill(rds, freq: dev->radio_rx_freq, use_alternate: alt);
88 }
89 if (dev->radio_rx_rds_controls) {
90 v4l2_ctrl_s_ctrl(ctrl: dev->radio_rx_rds_pty, val: rds->pty);
91 v4l2_ctrl_s_ctrl(ctrl: dev->radio_rx_rds_ta, val: rds->ta);
92 v4l2_ctrl_s_ctrl(ctrl: dev->radio_rx_rds_tp, val: rds->tp);
93 v4l2_ctrl_s_ctrl(ctrl: dev->radio_rx_rds_ms, val: rds->ms);
94 v4l2_ctrl_s_ctrl_string(ctrl: dev->radio_rx_rds_psname, s: rds->psname);
95 v4l2_ctrl_s_ctrl_string(ctrl: dev->radio_rx_rds_radiotext, s: rds->radiotext);
96 if (!dev->radio_rds_loop)
97 dev->radio_rx_rds_use_alternates = !dev->radio_rx_rds_use_alternates;
98 }
99 vivid_rds_generate(rds);
100}
101
102/*
103 * Calculate the emulated signal quality taking into account the frequency
104 * the transmitter is using.
105 */
106static void vivid_radio_calc_sig_qual(struct vivid_dev *dev)
107{
108 int mod = 16000;
109 int delta = 800;
110 int sig_qual, sig_qual_tx = mod;
111
112 /*
113 * For SW and FM there is a channel every 1000 kHz, for AM there is one
114 * every 100 kHz.
115 */
116 if (dev->radio_rx_freq <= AM_FREQ_RANGE_HIGH) {
117 mod /= 10;
118 delta /= 10;
119 }
120 sig_qual = (dev->radio_rx_freq + delta) % mod - delta;
121 if (dev->has_radio_tx)
122 sig_qual_tx = dev->radio_rx_freq - dev->radio_tx_freq;
123 if (abs(sig_qual_tx) <= abs(sig_qual)) {
124 sig_qual = sig_qual_tx;
125 /*
126 * Zero the internal rds buffer if we are going to loop
127 * rds blocks.
128 */
129 if (!dev->radio_rds_loop && !dev->radio_tx_rds_controls)
130 memset(dev->rds_gen.data, 0,
131 sizeof(dev->rds_gen.data));
132 dev->radio_rds_loop = dev->radio_rx_freq >= FM_FREQ_RANGE_LOW;
133 } else {
134 dev->radio_rds_loop = false;
135 }
136 if (dev->radio_rx_freq <= AM_FREQ_RANGE_HIGH)
137 sig_qual *= 10;
138 dev->radio_rx_sig_qual = sig_qual;
139}
140
141int vivid_radio_g_frequency(struct file *file, const unsigned *pfreq, struct v4l2_frequency *vf)
142{
143 if (vf->tuner != 0)
144 return -EINVAL;
145 vf->frequency = *pfreq;
146 return 0;
147}
148
149int vivid_radio_s_frequency(struct file *file, unsigned *pfreq, const struct v4l2_frequency *vf)
150{
151 struct vivid_dev *dev = video_drvdata(file);
152 unsigned freq;
153 unsigned band;
154
155 if (vf->tuner != 0)
156 return -EINVAL;
157
158 if (vf->frequency >= (FM_FREQ_RANGE_LOW + SW_FREQ_RANGE_HIGH) / 2)
159 band = BAND_FM;
160 else if (vf->frequency <= (AM_FREQ_RANGE_HIGH + SW_FREQ_RANGE_LOW) / 2)
161 band = BAND_AM;
162 else
163 band = BAND_SW;
164
165 freq = clamp_t(u32, vf->frequency, vivid_radio_bands[band].rangelow,
166 vivid_radio_bands[band].rangehigh);
167 *pfreq = freq;
168
169 /*
170 * For both receiver and transmitter recalculate the signal quality
171 * (since that depends on both frequencies) and re-init the rds
172 * generator.
173 */
174 vivid_radio_calc_sig_qual(dev);
175 vivid_radio_rds_init(dev);
176 return 0;
177}
178

source code of linux/drivers/media/test-drivers/vivid/vivid-radio-common.c