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 
21 static 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);
29 
30 		if (!(value & (STK1160_AC97CTL_0_CR | STK1160_AC97CTL_0_CW)))
31 			return 0;
32 
33 		usleep_range(50, 100);
34 	}
35 
36 	stk1160_err("AC97 transfer took too long, this should never happen!");
37 	return -EBUSY;
38 }
39 
40 static 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, reg);
44 
45 	/* Set codec command */
46 	stk1160_write_reg(dev, STK1160_AC97_CMD, value & 0xff);
47 	stk1160_write_reg(dev, STK1160_AC97_CMD + 1, (value & 0xff00) >> 8);
48 
49 	/* Set command write bit to initiate write operation */
50 	stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);
51 
52 	/* Wait for command write bit to be cleared */
53 	stk1160_ac97_wait_transfer_complete(dev);
54 }
55 
56 #ifdef DEBUG
57 static 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 
80 void 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 
107 static int stk1160_has_audio(struct stk1160 *dev)
108 {
109 	u8 value;
110 
111 	stk1160_read_reg(dev, STK1160_POSV_L, &value);
112 	return !(value & STK1160_POSV_L_ACDOUT);
113 }
114 
115 static int stk1160_has_ac97(struct stk1160 *dev)
116 {
117 	u8 value;
118 
119 	stk1160_read_reg(dev, STK1160_POSV_L, &value);
120 	return !(value & STK1160_POSV_L_ACSYNC);
121 }
122 
123 void 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, 0x94);
137 	stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);
138 
139 	/* Set 16-bit audio data and choose L&R channel*/
140 	stk1160_write_reg(dev, STK1160_AC97CTL_1 + 2, 0x01);
141 	stk1160_write_reg(dev, STK1160_AC97CTL_1 + 3, 0x00);
142 
143 	/* Setup channels */
144 	stk1160_write_ac97(dev, 0x12, 0x8808); /* CD volume */
145 	stk1160_write_ac97(dev, 0x10, 0x0808); /* Line-in volume */
146 	stk1160_write_ac97(dev, 0x0e, 0x0008); /* MIC volume (mono) */
147 	stk1160_write_ac97(dev, 0x16, 0x0808); /* Aux volume */
148 	stk1160_write_ac97(dev, 0x1a, 0x0404); /* Record select */
149 	stk1160_write_ac97(dev, 0x02, 0x0000); /* Master volume */
150 	stk1160_write_ac97(dev, 0x1c, 0x0808); /* Record gain */
151 
152 #ifdef DEBUG
153 	stk1160_ac97_dump_regs(dev);
154 #endif
155 }
156