sound/soc/mediatek/common/mtk-afe-platform-driver.c

/*
 * mtk-afe-platform-driver.c  --  Mediatek afe platform driver
 *
 * Copyright (c) 2016 MediaTek Inc.
 * Author: Garlic Tseng <garlic.tseng@mediatek.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <sound/soc.h>

#include "mtk-afe-platform-driver.h"
#include "mtk-base-afe.h"

static snd_pcm_uframes_t mtk_afe_pcm_pointer
			 (struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct mtk_base_afe *afe = snd_soc_platform_get_drvdata(rtd->platform);
	struct mtk_base_afe_memif *memif = &afe->memif[rtd->cpu_dai->id];
	const struct mtk_base_memif_data *memif_data = memif->data;
	struct regmap *regmap = afe->regmap;
	struct device *dev = afe->dev;
	int reg_ofs_base = memif_data->reg_ofs_base;
	int reg_ofs_cur = memif_data->reg_ofs_cur;
	unsigned int hw_ptr = 0, hw_base = 0;
	int ret, pcm_ptr_bytes;

	ret = regmap_read(regmap, reg_ofs_cur, &hw_ptr);
	if (ret || hw_ptr == 0) {
		dev_err(dev, "%s hw_ptr err\n", __func__);
		pcm_ptr_bytes = 0;
		goto POINTER_RETURN_FRAMES;
	}

	ret = regmap_read(regmap, reg_ofs_base, &hw_base);
	if (ret || hw_base == 0) {
		dev_err(dev, "%s hw_ptr err\n", __func__);
		pcm_ptr_bytes = 0;
		goto POINTER_RETURN_FRAMES;
	}

	pcm_ptr_bytes = hw_ptr - hw_base;

POINTER_RETURN_FRAMES:
	return bytes_to_frames(substream->runtime, pcm_ptr_bytes);
}

static const struct snd_pcm_ops mtk_afe_pcm_ops = {
	.ioctl = snd_pcm_lib_ioctl,
	.pointer = mtk_afe_pcm_pointer,
};

static int mtk_afe_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
	size_t size;
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	struct mtk_base_afe *afe = snd_soc_platform_get_drvdata(rtd->platform);

	size = afe->mtk_afe_hardware->buffer_bytes_max;
	return snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
						     card->dev, size, size);
}

static void mtk_afe_pcm_free(struct snd_pcm *pcm)
{
	snd_pcm_lib_preallocate_free_for_all(pcm);
}

const struct snd_soc_platform_driver mtk_afe_pcm_platform = {
	.ops = &mtk_afe_pcm_ops,
	.pcm_new = mtk_afe_pcm_new,
	.pcm_free = mtk_afe_pcm_free,
};
EXPORT_SYMBOL_GPL(mtk_afe_pcm_platform);

MODULE_DESCRIPTION("Mediatek simple platform driver");
MODULE_AUTHOR("Garlic Tseng <garlic.tseng@mediatek.com>");
MODULE_LICENSE("GPL v2");