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}