1 /* 2 * STK1160 driver 3 * 4 * Copyright (C) 2012 Ezequiel Garcia 5 * <elezegarcia--a.t--gmail.com> 6 * 7 * Based on Easycap driver by R.M. Thomas 8 * Copyright (C) 2010 R.M. Thomas 9 * <rmthomas--a.t--sciolus.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 */ 22 23 #include <linux/module.h> 24 #include <sound/core.h> 25 #include <sound/initval.h> 26 #include <sound/ac97_codec.h> 27 28 #include "stk1160.h" 29 #include "stk1160-reg.h" 30 31 static struct snd_ac97 *stk1160_ac97; 32 33 static void stk1160_write_ac97(struct snd_ac97 *ac97, u16 reg, u16 value) 34 { 35 struct stk1160 *dev = ac97->private_data; 36 37 /* Set codec register address */ 38 stk1160_write_reg(dev, STK1160_AC97_ADDR, reg); 39 40 /* Set codec command */ 41 stk1160_write_reg(dev, STK1160_AC97_CMD, value & 0xff); 42 stk1160_write_reg(dev, STK1160_AC97_CMD + 1, (value & 0xff00) >> 8); 43 44 /* 45 * Set command write bit to initiate write operation. 46 * The bit will be cleared when transfer is done. 47 */ 48 stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c); 49 } 50 51 static u16 stk1160_read_ac97(struct snd_ac97 *ac97, u16 reg) 52 { 53 struct stk1160 *dev = ac97->private_data; 54 u8 vall = 0; 55 u8 valh = 0; 56 57 /* Set codec register address */ 58 stk1160_write_reg(dev, STK1160_AC97_ADDR, reg); 59 60 /* 61 * Set command read bit to initiate read operation. 62 * The bit will be cleared when transfer is done. 63 */ 64 stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8b); 65 66 /* Retrieve register value */ 67 stk1160_read_reg(dev, STK1160_AC97_CMD, &vall); 68 stk1160_read_reg(dev, STK1160_AC97_CMD + 1, &valh); 69 70 return (valh << 8) | vall; 71 } 72 73 static void stk1160_reset_ac97(struct snd_ac97 *ac97) 74 { 75 struct stk1160 *dev = ac97->private_data; 76 /* Two-step reset AC97 interface and hardware codec */ 77 stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x94); 78 stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x88); 79 80 /* Set 16-bit audio data and choose L&R channel*/ 81 stk1160_write_reg(dev, STK1160_AC97CTL_1 + 2, 0x01); 82 } 83 84 static struct snd_ac97_bus_ops stk1160_ac97_ops = { 85 .read = stk1160_read_ac97, 86 .write = stk1160_write_ac97, 87 .reset = stk1160_reset_ac97, 88 }; 89 90 int stk1160_ac97_register(struct stk1160 *dev) 91 { 92 struct snd_card *card = NULL; 93 struct snd_ac97_bus *ac97_bus; 94 struct snd_ac97_template ac97_template; 95 int rc; 96 97 /* 98 * Just want a card to access ac96 controls, 99 * the actual capture interface will be handled by snd-usb-audio 100 */ 101 rc = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, 102 THIS_MODULE, 0, &card); 103 if (rc < 0) 104 return rc; 105 106 snd_card_set_dev(card, dev->dev); 107 108 /* TODO: I'm not sure where should I get these names :-( */ 109 snprintf(card->shortname, sizeof(card->shortname), 110 "stk1160-mixer"); 111 snprintf(card->longname, sizeof(card->longname), 112 "stk1160 ac97 codec mixer control"); 113 strncpy(card->driver, dev->dev->driver->name, sizeof(card->driver)); 114 115 rc = snd_ac97_bus(card, 0, &stk1160_ac97_ops, NULL, &ac97_bus); 116 if (rc) 117 goto err; 118 119 /* We must set private_data before calling snd_ac97_mixer */ 120 memset(&ac97_template, 0, sizeof(ac97_template)); 121 ac97_template.private_data = dev; 122 ac97_template.scaps = AC97_SCAP_SKIP_MODEM; 123 rc = snd_ac97_mixer(ac97_bus, &ac97_template, &stk1160_ac97); 124 if (rc) 125 goto err; 126 127 dev->snd_card = card; 128 rc = snd_card_register(card); 129 if (rc) 130 goto err; 131 132 return 0; 133 134 err: 135 dev->snd_card = NULL; 136 snd_card_free(card); 137 return rc; 138 } 139 140 int stk1160_ac97_unregister(struct stk1160 *dev) 141 { 142 struct snd_card *card = dev->snd_card; 143 144 /* 145 * We need to check usb_device, 146 * because ac97 release attempts to communicate with codec 147 */ 148 if (card && dev->udev) 149 snd_card_free(card); 150 151 return 0; 152 } 153