1/* 2 * sound/oss/sh_dac_audio.c 3 * 4 * SH DAC based sound :( 5 * 6 * Copyright (C) 2004,2005 Andriy Skulysh 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12#include <linux/module.h> 13#include <linux/init.h> 14#include <linux/sched.h> 15#include <linux/linkage.h> 16#include <linux/slab.h> 17#include <linux/fs.h> 18#include <linux/sound.h> 19#include <linux/smp_lock.h> 20#include <linux/soundcard.h> 21#include <linux/interrupt.h> 22#include <linux/hrtimer.h> 23#include <asm/io.h> 24#include <asm/uaccess.h> 25#include <asm/irq.h> 26#include <asm/delay.h> 27#include <asm/clock.h> 28#include <cpu/dac.h> 29#include <asm/machvec.h> 30#include <mach/hp6xx.h> 31#include <asm/hd64461.h> 32 33#define MODNAME "sh_dac_audio" 34 35#define BUFFER_SIZE 48000 36 37static int rate; 38static int empty; 39static char *data_buffer, *buffer_begin, *buffer_end; 40static int in_use, device_major; 41static struct hrtimer hrtimer; 42static ktime_t wakeups_per_second; 43 44static void dac_audio_start_timer(void) 45{ 46 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL); 47} 48 49static void dac_audio_stop_timer(void) 50{ 51 hrtimer_cancel(&hrtimer); 52} 53 54static void dac_audio_reset(void) 55{ 56 dac_audio_stop_timer(); 57 buffer_begin = buffer_end = data_buffer; 58 empty = 1; 59} 60 61static void dac_audio_sync(void) 62{ 63 while (!empty) 64 schedule(); 65} 66 67static void dac_audio_start(void) 68{ 69 if (mach_is_hp6xx()) { 70 u16 v = __raw_readw(HD64461_GPADR); 71 v &= ~HD64461_GPADR_SPEAKER; 72 __raw_writew(v, HD64461_GPADR); 73 } 74 75 sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); 76} 77static void dac_audio_stop(void) 78{ 79 dac_audio_stop_timer(); 80 81 if (mach_is_hp6xx()) { 82 u16 v = __raw_readw(HD64461_GPADR); 83 v |= HD64461_GPADR_SPEAKER; 84 __raw_writew(v, HD64461_GPADR); 85 } 86 87 sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); 88 sh_dac_disable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); 89} 90 91static void dac_audio_set_rate(void) 92{ 93 wakeups_per_second = ktime_set(0, 1000000000 / rate); 94} 95 96static int dac_audio_ioctl(struct file *file, 97 unsigned int cmd, unsigned long arg) 98{ 99 int val; 100 101 switch (cmd) { 102 case OSS_GETVERSION: 103 return put_user(SOUND_VERSION, (int *)arg); 104 105 case SNDCTL_DSP_SYNC: 106 dac_audio_sync(); 107 return 0; 108 109 case SNDCTL_DSP_RESET: 110 dac_audio_reset(); 111 return 0; 112 113 case SNDCTL_DSP_GETFMTS: 114 return put_user(AFMT_U8, (int *)arg); 115 116 case SNDCTL_DSP_SETFMT: 117 return put_user(AFMT_U8, (int *)arg); 118 119 case SNDCTL_DSP_NONBLOCK: 120 spin_lock(&file->f_lock); 121 file->f_flags |= O_NONBLOCK; 122 spin_unlock(&file->f_lock); 123 return 0; 124 125 case SNDCTL_DSP_GETCAPS: 126 return 0; 127 128 case SOUND_PCM_WRITE_RATE: 129 val = *(int *)arg; 130 if (val > 0) { 131 rate = val; 132 dac_audio_set_rate(); 133 } 134 return put_user(rate, (int *)arg); 135 136 case SNDCTL_DSP_STEREO: 137 return put_user(0, (int *)arg); 138 139 case SOUND_PCM_WRITE_CHANNELS: 140 return put_user(1, (int *)arg); 141 142 case SNDCTL_DSP_SETDUPLEX: 143 return -EINVAL; 144 145 case SNDCTL_DSP_PROFILE: 146 return -EINVAL; 147 148 case SNDCTL_DSP_GETBLKSIZE: 149 return put_user(BUFFER_SIZE, (int *)arg); 150 151 case SNDCTL_DSP_SETFRAGMENT: 152 return 0; 153 154 default: 155 printk(KERN_ERR "sh_dac_audio: unimplemented ioctl=0x%x\n", 156 cmd); 157 return -EINVAL; 158 } 159 return -EINVAL; 160} 161 162static long dac_audio_unlocked_ioctl(struct file *file, u_int cmd, u_long arg) 163{ 164 int ret; 165 166 lock_kernel(); 167 ret = dac_audio_ioctl(file, cmd, arg); 168 unlock_kernel(); 169 170 return ret; 171} 172 173static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count, 174 loff_t * ppos) 175{ 176 int free; 177 int nbytes; 178 179 if (!count) { 180 dac_audio_sync(); 181 return 0; 182 } 183 184 free = buffer_begin - buffer_end; 185 186 if (free < 0) 187 free += BUFFER_SIZE; 188 if ((free == 0) && (empty)) 189 free = BUFFER_SIZE; 190 if (count > free) 191 count = free; 192 if (buffer_begin > buffer_end) { 193 if (copy_from_user((void *)buffer_end, buf, count)) 194 return -EFAULT; 195 196 buffer_end += count; 197 } else { 198 nbytes = data_buffer + BUFFER_SIZE - buffer_end; 199 if (nbytes > count) { 200 if (copy_from_user((void *)buffer_end, buf, count)) 201 return -EFAULT; 202 buffer_end += count; 203 } else { 204 if (copy_from_user((void *)buffer_end, buf, nbytes)) 205 return -EFAULT; 206 if (copy_from_user 207 ((void *)data_buffer, buf + nbytes, count - nbytes)) 208 return -EFAULT; 209 buffer_end = data_buffer + count - nbytes; 210 } 211 } 212 213 if (empty) { 214 empty = 0; 215 dac_audio_start_timer(); 216 } 217 218 return count; 219} 220 221static ssize_t dac_audio_read(struct file *file, char *buf, size_t count, 222 loff_t * ppos) 223{ 224 return -EINVAL; 225} 226 227static int dac_audio_open(struct inode *inode, struct file *file) 228{ 229 if (file->f_mode & FMODE_READ) 230 return -ENODEV; 231 232 lock_kernel(); 233 if (in_use) { 234 unlock_kernel(); 235 return -EBUSY; 236 } 237 238 in_use = 1; 239 240 dac_audio_start(); 241 unlock_kernel(); 242 return 0; 243} 244 245static int dac_audio_release(struct inode *inode, struct file *file) 246{ 247 dac_audio_sync(); 248 dac_audio_stop(); 249 in_use = 0; 250 251 return 0; 252} 253 254const struct file_operations dac_audio_fops = { 255 .read = dac_audio_read, 256 .write = dac_audio_write, 257 .unlocked_ioctl = dac_audio_unlocked_ioctl, 258 .open = dac_audio_open, 259 .release = dac_audio_release, 260}; 261 262static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle) 263{ 264 if (!empty) { 265 sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); 266 buffer_begin++; 267 268 if (buffer_begin == data_buffer + BUFFER_SIZE) 269 buffer_begin = data_buffer; 270 if (buffer_begin == buffer_end) 271 empty = 1; 272 } 273 274 if (!empty) 275 hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL); 276 277 return HRTIMER_NORESTART; 278} 279 280static int __init dac_audio_init(void) 281{ 282 if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) { 283 printk(KERN_ERR "Cannot register dsp device"); 284 return device_major; 285 } 286 287 in_use = 0; 288 289 data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); 290 if (data_buffer == NULL) 291 return -ENOMEM; 292 293 dac_audio_reset(); 294 rate = 8000; 295 dac_audio_set_rate(); 296 297 /* Today: High Resolution Timer driven DAC playback. 298 * The timer callback gets called once per sample. Ouch. 299 * 300 * Future: A much better approach would be to use the 301 * SH7720 CMT+DMAC+DAC hardware combination like this: 302 * - Program sample rate using CMT0 or CMT1 303 * - Program DMAC to use CMT for timing and output to DAC 304 * - Play sound using DMAC, let CPU sleep. 305 * - While at it, rewrite this driver to use ALSA. 306 */ 307 308 hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 309 hrtimer.function = sh_dac_audio_timer; 310 311 return 0; 312} 313 314static void __exit dac_audio_exit(void) 315{ 316 unregister_sound_dsp(device_major); 317 kfree((void *)data_buffer); 318} 319 320module_init(dac_audio_init); 321module_exit(dac_audio_exit); 322 323MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua"); 324MODULE_DESCRIPTION("SH DAC sound driver"); 325MODULE_LICENSE("GPL"); 326