diff options
Diffstat (limited to 'sound/drivers/pcsp/pcsp_lib.c')
| -rw-r--r-- | sound/drivers/pcsp/pcsp_lib.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/sound/drivers/pcsp/pcsp_lib.c b/sound/drivers/pcsp/pcsp_lib.c new file mode 100644 index 0000000000..773db4bf08 --- /dev/null +++ b/sound/drivers/pcsp/pcsp_lib.c @@ -0,0 +1,352 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PC-Speaker driver for Linux + * + * Copyright (C) 1993-1997 Michael Beck + * Copyright (C) 1997-2001 David Woodhouse + * Copyright (C) 2001-2008 Stas Sergeev + */ + +#include <linux/module.h> +#include <linux/gfp.h> +#include <linux/moduleparam.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <sound/pcm.h> +#include "pcsp.h" + +static bool nforce_wa; +module_param(nforce_wa, bool, 0444); +MODULE_PARM_DESC(nforce_wa, "Apply NForce chipset workaround " + "(expect bad sound)"); + +#define DMIX_WANTS_S16 1 + +/* + * Call snd_pcm_period_elapsed in a work + * This avoids spinlock messes and long-running irq contexts + */ +static void pcsp_call_pcm_elapsed(struct work_struct *work) +{ + if (atomic_read(&pcsp_chip.timer_active)) { + struct snd_pcm_substream *substream; + substream = pcsp_chip.playback_substream; + if (substream) + snd_pcm_period_elapsed(substream); + } +} + +static DECLARE_WORK(pcsp_pcm_work, pcsp_call_pcm_elapsed); + +/* write the port and returns the next expire time in ns; + * called at the trigger-start and in hrtimer callback + */ +static u64 pcsp_timer_update(struct snd_pcsp *chip) +{ + unsigned char timer_cnt, val; + u64 ns; + struct snd_pcm_substream *substream; + struct snd_pcm_runtime *runtime; + unsigned long flags; + + if (chip->thalf) { + outb(chip->val61, 0x61); + chip->thalf = 0; + return chip->ns_rem; + } + + substream = chip->playback_substream; + if (!substream) + return 0; + + runtime = substream->runtime; + /* assume it is mono! */ + val = runtime->dma_area[chip->playback_ptr + chip->fmt_size - 1]; + if (chip->is_signed) + val ^= 0x80; + timer_cnt = val * CUR_DIV() / 256; + + if (timer_cnt && chip->enable) { + raw_spin_lock_irqsave(&i8253_lock, flags); + if (!nforce_wa) { + outb_p(chip->val61, 0x61); + outb_p(timer_cnt, 0x42); + outb(chip->val61 ^ 1, 0x61); + } else { + outb(chip->val61 ^ 2, 0x61); + chip->thalf = 1; + } + raw_spin_unlock_irqrestore(&i8253_lock, flags); + } + + chip->ns_rem = PCSP_PERIOD_NS(); + ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem); + chip->ns_rem -= ns; + return ns; +} + +static void pcsp_pointer_update(struct snd_pcsp *chip) +{ + struct snd_pcm_substream *substream; + size_t period_bytes, buffer_bytes; + int periods_elapsed; + unsigned long flags; + + /* update the playback position */ + substream = chip->playback_substream; + if (!substream) + return; + + period_bytes = snd_pcm_lib_period_bytes(substream); + buffer_bytes = snd_pcm_lib_buffer_bytes(substream); + + spin_lock_irqsave(&chip->substream_lock, flags); + chip->playback_ptr += PCSP_INDEX_INC() * chip->fmt_size; + periods_elapsed = chip->playback_ptr - chip->period_ptr; + if (periods_elapsed < 0) { +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: buffer_bytes mod period_bytes != 0 ? " + "(%zi %zi %zi)\n", + chip->playback_ptr, period_bytes, buffer_bytes); +#endif + periods_elapsed += buffer_bytes; + } + periods_elapsed /= period_bytes; + /* wrap the pointer _before_ calling snd_pcm_period_elapsed(), + * or ALSA will BUG on us. */ + chip->playback_ptr %= buffer_bytes; + + if (periods_elapsed) { + chip->period_ptr += periods_elapsed * period_bytes; + chip->period_ptr %= buffer_bytes; + queue_work(system_highpri_wq, &pcsp_pcm_work); + } + spin_unlock_irqrestore(&chip->substream_lock, flags); +} + +enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle) +{ + struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer); + int pointer_update; + u64 ns; + + if (!atomic_read(&chip->timer_active) || !chip->playback_substream) + return HRTIMER_NORESTART; + + pointer_update = !chip->thalf; + ns = pcsp_timer_update(chip); + if (!ns) { + printk(KERN_WARNING "PCSP: unexpected stop\n"); + return HRTIMER_NORESTART; + } + + if (pointer_update) + pcsp_pointer_update(chip); + + hrtimer_forward_now(handle, ns_to_ktime(ns)); + + return HRTIMER_RESTART; +} + +static int pcsp_start_playing(struct snd_pcsp *chip) +{ +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: start_playing called\n"); +#endif + if (atomic_read(&chip->timer_active)) { + printk(KERN_ERR "PCSP: Timer already active\n"); + return -EIO; + } + + raw_spin_lock(&i8253_lock); + chip->val61 = inb(0x61) | 0x03; + outb_p(0x92, 0x43); /* binary, mode 1, LSB only, ch 2 */ + raw_spin_unlock(&i8253_lock); + atomic_set(&chip->timer_active, 1); + chip->thalf = 0; + + hrtimer_start(&pcsp_chip.timer, 0, HRTIMER_MODE_REL); + return 0; +} + +static void pcsp_stop_playing(struct snd_pcsp *chip) +{ +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: stop_playing called\n"); +#endif + if (!atomic_read(&chip->timer_active)) + return; + + atomic_set(&chip->timer_active, 0); + raw_spin_lock(&i8253_lock); + /* restore the timer */ + outb_p(0xb6, 0x43); /* binary, mode 3, LSB/MSB, ch 2 */ + outb(chip->val61 & 0xFC, 0x61); + raw_spin_unlock(&i8253_lock); +} + +/* + * Force to stop and sync the stream + */ +void pcsp_sync_stop(struct snd_pcsp *chip) +{ + local_irq_disable(); + pcsp_stop_playing(chip); + local_irq_enable(); + hrtimer_cancel(&chip->timer); + cancel_work_sync(&pcsp_pcm_work); +} + +static int snd_pcsp_playback_close(struct snd_pcm_substream *substream) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: close called\n"); +#endif + pcsp_sync_stop(chip); + chip->playback_substream = NULL; + return 0; +} + +static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *hw_params) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); + pcsp_sync_stop(chip); + return 0; +} + +static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: hw_free called\n"); +#endif + pcsp_sync_stop(chip); + return 0; +} + +static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); + pcsp_sync_stop(chip); + chip->playback_ptr = 0; + chip->period_ptr = 0; + chip->fmt_size = + snd_pcm_format_physical_width(substream->runtime->format) >> 3; + chip->is_signed = snd_pcm_format_signed(substream->runtime->format); +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: prepare called, " + "size=%zi psize=%zi f=%zi f1=%i fsize=%i\n", + snd_pcm_lib_buffer_bytes(substream), + snd_pcm_lib_period_bytes(substream), + snd_pcm_lib_buffer_bytes(substream) / + snd_pcm_lib_period_bytes(substream), + substream->runtime->periods, + chip->fmt_size); +#endif + return 0; +} + +static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: trigger called\n"); +#endif + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_RESUME: + return pcsp_start_playing(chip); + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_SUSPEND: + pcsp_stop_playing(chip); + break; + default: + return -EINVAL; + } + return 0; +} + +static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream + *substream) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); + unsigned int pos; + spin_lock(&chip->substream_lock); + pos = chip->playback_ptr; + spin_unlock(&chip->substream_lock); + return bytes_to_frames(substream->runtime, pos); +} + +static const struct snd_pcm_hardware snd_pcsp_playback = { + .info = (SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_HALF_DUPLEX | + SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID), + .formats = (SNDRV_PCM_FMTBIT_U8 +#if DMIX_WANTS_S16 + | SNDRV_PCM_FMTBIT_S16_LE +#endif + ), + .rates = SNDRV_PCM_RATE_KNOT, + .rate_min = PCSP_DEFAULT_SRATE, + .rate_max = PCSP_DEFAULT_SRATE, + .channels_min = 1, + .channels_max = 1, + .buffer_bytes_max = PCSP_BUFFER_SIZE, + .period_bytes_min = 64, + .period_bytes_max = PCSP_MAX_PERIOD_SIZE, + .periods_min = 2, + .periods_max = PCSP_MAX_PERIODS, + .fifo_size = 0, +}; + +static int snd_pcsp_playback_open(struct snd_pcm_substream *substream) +{ + struct snd_pcsp *chip = snd_pcm_substream_chip(substream); + struct snd_pcm_runtime *runtime = substream->runtime; +#if PCSP_DEBUG + printk(KERN_INFO "PCSP: open called\n"); +#endif + if (atomic_read(&chip->timer_active)) { + printk(KERN_ERR "PCSP: still active!!\n"); + return -EBUSY; + } + runtime->hw = snd_pcsp_playback; + chip->playback_substream = substream; + return 0; +} + +static const struct snd_pcm_ops snd_pcsp_playback_ops = { + .open = snd_pcsp_playback_open, + .close = snd_pcsp_playback_close, + .hw_params = snd_pcsp_playback_hw_params, + .hw_free = snd_pcsp_playback_hw_free, + .prepare = snd_pcsp_playback_prepare, + .trigger = snd_pcsp_trigger, + .pointer = snd_pcsp_playback_pointer, +}; + +int snd_pcsp_new_pcm(struct snd_pcsp *chip) +{ + int err; + + err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm); + if (err < 0) + return err; + + snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK, + &snd_pcsp_playback_ops); + + chip->pcm->private_data = chip; + chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX; + strcpy(chip->pcm->name, "pcsp"); + + snd_pcm_set_managed_buffer_all(chip->pcm, + SNDRV_DMA_TYPE_CONTINUOUS, + NULL, + PCSP_BUFFER_SIZE, + PCSP_BUFFER_SIZE); + + return 0; +} |