path: root/sound/aoa/soundbus/i2sbus/pcm.c

/*
 * i2sbus driver -- pcm routines
 *
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * GPL v2, can be found in COPYING.
 */

#include <asm/io.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <asm/macio.h>
#include <linux/pci.h>
#include <linux/module.h>
#include "../soundbus.h"
#include "i2sbus.h"

static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
				struct pcm_info **pi, struct pcm_info **other)
{
	if (in) {
		if (pi)
			*pi = &i2sdev->in;
		if (other)
			*other = &i2sdev->out;
	} else {
		if (pi)
			*pi = &i2sdev->out;
		if (other)
			*other = &i2sdev->in;
	}
}

static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
{
	/* sclk must be derived from mclk! */
	if (mclk % sclk)
		return -1;
	/* derive sclk register value */
	if (i2s_sf_sclkdiv(mclk / sclk, out))
		return -1;

	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
			return 0;
		}
	}
	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
			return 0;
		}
	}
	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
			return 0;
		}
	}
	return -1;
}

#define CHECK_RATE(rate)						\
	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
		int dummy;						\
		if (clock_and_divisors(sysclock_factor,			\
				       bus_factor, rate, &dummy))	\
			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
	} } while (0)

static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
{
	struct pcm_info *pi, *other;
	struct soundbus_dev *sdev;
	int masks_inited = 0, err;
	struct codec_info_item *cii, *rev;
	struct snd_pcm_hardware *hw;
	u64 formats = 0;
	unsigned int rates = 0;
	struct transfer_info v;
	int result = 0;
	int bus_factor = 0, sysclock_factor = 0;
	int found_this;

	mutex_lock(&i2sdev->lock);

	get_pcm_info(i2sdev, in, &pi, &other);

	hw = &pi->substream->runtime->hw;
	sdev = &i2sdev->sound;

	if (pi->active) {
		/* alsa messed up */
		result = -EBUSY;
		goto out_unlock;
	}

	/* we now need to assign the hw */
	list_for_each_entry(cii, &sdev->codec_list, list) {
		struct transfer_info *ti = cii->codec->transfers;
		bus_factor = cii->codec->bus_factor;
		sysclock_factor = cii->codec->sysclock_factor;
		while (ti->formats && ti->rates) {
			v = *ti;
			if (ti->transfer_in == in
			    && cii->codec->usable(cii, ti, &v)) {
				if (masks_inited) {
					formats &= v.formats;
					rates &= v.rates;
				}