/* * sound/oss/sh_dac_audio.c * * SH DAC based sound :( * * Copyright (C) 2004,2005 Andriy Skulysh * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/linkage.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/sound.h> #include <linux/smp_lock.h> #include <linux/soundcard.h> #include <linux/interrupt.h> #include <linux/hrtimer.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/irq.h> #include <asm/delay.h> #include <asm/clock.h> #include <cpu/dac.h> #include <asm/machvec.h> #include <mach/hp6xx.h> #include <asm/hd64461.h> #define MODNAME "sh_dac_audio" #define BUFFER_SIZE 48000 static int rate; static int empty; static char *data_buffer, *buffer_begin, *buffer_end; static int in_use, device_major; static struct hrtimer hrtimer; static ktime_t wakeups_per_second; static void dac_audio_start_timer(void) { hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL); } static void dac_audio_stop_timer(void) { hrtimer_cancel(&hrtimer); } static void dac_audio_reset(void) { dac_audio_stop_timer(); buffer_begin = buffer_end = data_buffer; empty = 1; } static void dac_audio_sync(void) { while (!empty) schedule(); } static void dac_audio_start(void) { if (mach_is_hp6xx()) { u16 v = __raw_readw(HD64461_GPADR); v &= ~HD64461_GPADR_SPEAKER; __raw_writew(v, HD64461_GPADR); } sh_dac_enable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); } static void dac_audio_stop(void) { dac_audio_stop_timer(); if (mach_is_hp6xx()) { u16 v = __raw_readw(HD64461_GPADR); v |= HD64461_GPADR_SPEAKER; __raw_writew(v, HD64461_GPADR); } sh_dac_output(0, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); sh_dac_disable(CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); } static void dac_audio_set_rate(void) { wakeups_per_second = ktime_set(0, 1000000000 / rate); } static int dac_audio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int val; switch (cmd) { case OSS_GETVERSION: return put_user(SOUND_VERSION, (int *)arg); case SNDCTL_DSP_SYNC: dac_audio_sync(); return 0; case SNDCTL_DSP_RESET: dac_audio_reset(); return 0; case SNDCTL_DSP_GETFMTS: return put_user(AFMT_U8, (int *)arg); case SNDCTL_DSP_SETFMT: return put_user(AFMT_U8, (int *)arg); case SNDCTL_DSP_NONBLOCK: spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_GETCAPS: return 0; case SOUND_PCM_WRITE_RATE: val = *(int *)arg; if (val > 0) { rate = val; dac_audio_set_rate(); } return put_user(rate, (int *)arg); case SNDCTL_DSP_STEREO: return put_user(0, (int *)arg); case SOUND_PCM_WRITE_CHANNELS: return put_user(1, (int *)arg); case SNDCTL_DSP_SETDUPLEX: return -EINVAL; case SNDCTL_DSP_PROFILE: return -EINVAL; case SNDCTL_DSP_GETBLKSIZE: return put_user(BUFFER_SIZE, (int *)arg); case SNDCTL_DSP_SETFRAGMENT: return 0; default: printk(KERN_ERR "sh_dac_audio: unimplemented ioctl=0x%x\n", cmd); return -EINVAL; } return -EINVAL; } static long dac_audio_unlocked_ioctl(struct file *file, u_int cmd, u_long arg) { int ret; lock_kernel(); ret = dac_audio_ioctl(file, cmd, arg); unlock_kernel(); return ret; } static ssize_t dac_audio_write(struct file *file, const char *buf, size_t count, loff_t * ppos) { int free; int nbytes; if (!count) { dac_audio_sync(); return 0; } free = buffer_begin - buffer_end; if (free < 0) free += BUFFER_SIZE; if ((free == 0) && (empty)) free = BUFFER_SIZE; if (count > free) count = free; if (buffer_begin > buffer_end) { if (copy_from_user((void *)buffer_end, buf, count)) return -EFAULT; buffer_end += count; } else { nbytes = data_buffer + BUFFER_SIZE - buffer_end; if (nbytes > count) { if (copy_from_user((void *)buffer_end, buf, count)) return -EFAULT; buffer_end += count; } else { if (copy_from_user((void *)buffer_end, buf, nbytes)) return -EFAULT; if (copy_from_user ((void *)data_buffer, buf + nbytes, count - nbytes)) return -EFAULT; buffer_end = data_buffer + count - nbytes; } } if (empty) { empty = 0; dac_audio_start_timer(); } return count; } static ssize_t dac_audio_read(struct file *file, char *buf, size_t count, loff_t * ppos) { return -EINVAL; } static int dac_audio_open(struct inode *inode, struct file *file) { if (file->f_mode & FMODE_READ) return -ENODEV; lock_kernel(); if (in_use) { unlock_kernel(); return -EBUSY; } in_use = 1; dac_audio_start(); unlock_kernel(); return 0; } static int dac_audio_release(struct inode *inode, struct file *file) { dac_audio_sync(); dac_audio_stop(); in_use = 0; return 0; } const struct file_operations dac_audio_fops = { .read = dac_audio_read, .write = dac_audio_write, .unlocked_ioctl = dac_audio_unlocked_ioctl, .open = dac_audio_open, .release = dac_audio_release, }; static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle) { if (!empty) { sh_dac_output(*buffer_begin, CONFIG_SOUND_SH_DAC_AUDIO_CHANNEL); buffer_begin++; if (buffer_begin == data_buffer + BUFFER_SIZE) buffer_begin = data_buffer; if (buffer_begin == buffer_end) empty = 1; } if (!empty) hrtimer_start(&hrtimer, wakeups_per_second, HRTIMER_MODE_REL); return HRTIMER_NORESTART; } static int __init dac_audio_init(void) { if ((device_major = register_sound_dsp(&dac_audio_fops, -1)) < 0) { printk(KERN_ERR "Cannot register dsp device"); return device_major; } in_use = 0; data_buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); if (data_buffer == NULL) return -ENOMEM; dac_audio_reset(); rate = 8000; dac_audio_set_rate(); /* Today: High Resolution Timer driven DAC playback. * The timer callback gets called once per sample. Ouch. * * Future: A much better approach would be to use the * SH7720 CMT+DMAC+DAC hardware combination like this: * - Program sample rate using CMT0 or CMT1 * - Program DMAC to use CMT for timing and output to DAC * - Play sound using DMAC, let CPU sleep. * - While at it, rewrite this driver to use ALSA. */ hrtimer_init(&hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer.function = sh_dac_audio_timer; return 0; } static void __exit dac_audio_exit(void) { unregister_sound_dsp(device_major); kfree((void *)data_buffer); } module_init(dac_audio_init); module_exit(dac_audio_exit); MODULE_AUTHOR("Andriy Skulysh, askulysh@image.kiev.ua"); MODULE_DESCRIPTION("SH DAC sound driver"); MODULE_LICENSE("GPL");