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);
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
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, 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
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);
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);
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, 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