1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * STK1160 driver
4 *
5 * Copyright (C) 2012 Ezequiel Garcia
6 * <elezegarcia--a.t--gmail.com>
7 *
8 * Copyright (C) 2016 Marcel Hasler
9 * <mahasler--a.t--gmail.com>
10 *
11 * Based on Easycap driver by R.M. Thomas
12 * Copyright (C) 2010 R.M. Thomas
13 * <rmthomas--a.t--sciolus.org>
14 */
15
16#include <linux/delay.h>
17
18#include "stk1160.h"
19#include "stk1160-reg.h"
20
21static int stk1160_ac97_wait_transfer_complete(struct stk1160 *dev)
22{
23 unsigned long timeout = jiffies + msecs_to_jiffies(STK1160_AC97_TIMEOUT);
24 u8 value;
25
26 /* Wait for AC97 transfer to complete */
27 while (time_is_after_jiffies(timeout)) {
28 stk1160_read_reg(dev, STK1160_AC97CTL_0, value: &value);
29
30 if (!(value & (STK1160_AC97CTL_0_CR | STK1160_AC97CTL_0_CW)))
31 return 0;
32
33 usleep_range(min: 50, max: 100);
34 }
35
36 stk1160_err("AC97 transfer took too long, this should never happen!");
37 return -EBUSY;
38}
39
40static void stk1160_write_ac97(struct stk1160 *dev, u16 reg, u16 value)
41{
42 /* Set codec register address */
43 stk1160_write_reg(dev, STK1160_AC97_ADDR, value: reg);
44
45 /* Set codec command */
46 stk1160_write_reg(dev, STK1160_AC97_CMD, value: value & 0xff);
47 stk1160_write_reg(dev, STK1160_AC97_CMD + 1, value: (value & 0xff00) >> 8);
48
49 /* Set command write bit to initiate write operation */
50 stk1160_write_reg(dev, STK1160_AC97CTL_0, value: 0x8c);
51
52 /* Wait for command write bit to be cleared */
53 stk1160_ac97_wait_transfer_complete(dev);
54}
55
56#ifdef DEBUG
57static u16 stk1160_read_ac97(struct stk1160 *dev, u16 reg)
58{
59 u8 vall = 0;
60 u8 valh = 0;
61
62 /* Set codec register address */
63 stk1160_write_reg(dev, STK1160_AC97_ADDR, reg);
64
65 /* Set command read bit to initiate read operation */
66 stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8b);
67
68 /* Wait for command read bit to be cleared */
69 if (stk1160_ac97_wait_transfer_complete(dev) < 0)
70 return 0;
71
72
73 /* Retrieve register value */
74 stk1160_read_reg(dev, STK1160_AC97_CMD, &vall);
75 stk1160_read_reg(dev, STK1160_AC97_CMD + 1, &valh);
76
77 return (valh << 8) | vall;
78}
79
80void stk1160_ac97_dump_regs(struct stk1160 *dev)
81{
82 u16 value;
83
84 value = stk1160_read_ac97(dev, 0x12); /* CD volume */
85 stk1160_dbg("0x12 == 0x%04x", value);
86
87 value = stk1160_read_ac97(dev, 0x10); /* Line-in volume */
88 stk1160_dbg("0x10 == 0x%04x", value);
89
90 value = stk1160_read_ac97(dev, 0x0e); /* MIC volume (mono) */
91 stk1160_dbg("0x0e == 0x%04x", value);
92
93 value = stk1160_read_ac97(dev, 0x16); /* Aux volume */
94 stk1160_dbg("0x16 == 0x%04x", value);
95
96 value = stk1160_read_ac97(dev, 0x1a); /* Record select */
97 stk1160_dbg("0x1a == 0x%04x", value);
98
99 value = stk1160_read_ac97(dev, 0x02); /* Master volume */
100 stk1160_dbg("0x02 == 0x%04x", value);
101
102 value = stk1160_read_ac97(dev, 0x1c); /* Record gain */
103 stk1160_dbg("0x1c == 0x%04x", value);
104}
105#endif
106
107static int stk1160_has_audio(struct stk1160 *dev)
108{
109 u8 value;
110
111 stk1160_read_reg(dev, STK1160_POSV_L, value: &value);
112 return !(value & STK1160_POSV_L_ACDOUT);
113}
114
115static int stk1160_has_ac97(struct stk1160 *dev)
116{
117 u8 value;
118
119 stk1160_read_reg(dev, STK1160_POSV_L, value: &value);
120 return !(value & STK1160_POSV_L_ACSYNC);
121}
122
123void stk1160_ac97_setup(struct stk1160 *dev)
124{
125 if (!stk1160_has_audio(dev)) {
126 stk1160_info("Device doesn't support audio, skipping AC97 setup.");
127 return;
128 }
129
130 if (!stk1160_has_ac97(dev)) {
131 stk1160_info("Device uses internal 8-bit ADC, skipping AC97 setup.");
132 return;
133 }
134
135 /* Two-step reset AC97 interface and hardware codec */
136 stk1160_write_reg(dev, STK1160_AC97CTL_0, value: 0x94);
137 stk1160_write_reg(dev, STK1160_AC97CTL_0, value: 0x8c);
138
139 /* Set 16-bit audio data and choose L&R channel*/
140 stk1160_write_reg(dev, STK1160_AC97CTL_1 + 2, value: 0x01);
141 stk1160_write_reg(dev, STK1160_AC97CTL_1 + 3, value: 0x00);
142
143 /* Setup channels */
144 stk1160_write_ac97(dev, reg: 0x12, value: 0x8808); /* CD volume */
145 stk1160_write_ac97(dev, reg: 0x10, value: 0x0808); /* Line-in volume */
146 stk1160_write_ac97(dev, reg: 0x0e, value: 0x0008); /* MIC volume (mono) */
147 stk1160_write_ac97(dev, reg: 0x16, value: 0x0808); /* Aux volume */
148 stk1160_write_ac97(dev, reg: 0x1a, value: 0x0404); /* Record select */
149 stk1160_write_ac97(dev, reg: 0x02, value: 0x0000); /* Master volume */
150 stk1160_write_ac97(dev, reg: 0x1c, value: 0x0808); /* Record gain */
151
152#ifdef DEBUG
153 stk1160_ac97_dump_regs(dev);
154#endif
155}
156

source code of linux/drivers/media/usb/stk1160/stk1160-ac97.c