spdif_in.c

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/*
 * ALSA SoC SPDIF In Audio Layer for spear processors
 *
 * Copyright (C) 2012 ST Microelectronics
 * Vipin Kumar <[email protected]>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/spear_dma.h>
#include <sound/spear_spdif.h>
#include "spdif_in_regs.h"

struct spdif_in_params {
    u32 format;
};

struct spdif_in_dev {
    struct clk *clk;
    struct spear_dma_data dma_params;
    struct spdif_in_params saved_params;
    void *io_base;
    struct device *dev;
    void (*reset_perip)(void);
    int irq;
};

static void spdif_in_configure(struct spdif_in_dev *host)
{
    u32 ctrl = SPDIF_IN_PRTYEN | SPDIF_IN_STATEN | SPDIF_IN_USREN |
        SPDIF_IN_VALEN | SPDIF_IN_BLKEN;
    ctrl |= SPDIF_MODE_16BIT | SPDIF_FIFO_THRES_16;

    writel(ctrl, host->io_base + SPDIF_IN_CTRL);
    writel(0xF, host->io_base + SPDIF_IN_IRQ_MASK);
}

static int spdif_in_startup(struct snd_pcm_substream *substream,
        struct snd_soc_dai *cpu_dai)
{
    struct spdif_in_dev *host = snd_soc_dai_get_drvdata(cpu_dai);

    if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
        return -EINVAL;

    snd_soc_dai_set_dma_data(cpu_dai, substream, (void *)&host->dma_params);
    return 0;
}

static void spdif_in_shutdown(struct snd_pcm_substream *substream,
        struct snd_soc_dai *dai)
{
    struct spdif_in_dev *host = snd_soc_dai_get_drvdata(dai);

    if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
        return;

    writel(0x0, host->io_base + SPDIF_IN_IRQ_MASK);
    snd_soc_dai_set_dma_data(dai, substream, NULL);
}

static void spdif_in_format(struct spdif_in_dev *host, u32 format)
{
    u32 ctrl = readl(host->io_base + SPDIF_IN_CTRL);

    switch (format) {
    case SNDRV_PCM_FORMAT_S16_LE:
        ctrl |= SPDIF_XTRACT_16BIT;
        break;

    case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:
        ctrl &= ~SPDIF_XTRACT_16BIT;
        break;
    }

    writel(ctrl, host->io_base + SPDIF_IN_CTRL);
}

static int spdif_in_hw_params(struct snd_pcm_substream *substream,
        struct snd_pcm_hw_params *params,
        struct snd_soc_dai *dai)
{
    struct spdif_in_dev *host = snd_soc_dai_get_drvdata(dai);
    u32 format;

    if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
        return -EINVAL;

    format = params_format(params);
    host->saved_params.format = format;

    return 0;
}

static int spdif_in_trigger(struct snd_pcm_substream *substream, int cmd,
        struct snd_soc_dai *dai)
{
    struct spdif_in_dev *host = snd_soc_dai_get_drvdata(dai);
    u32 ctrl;
    int ret = 0;

    if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
        return -EINVAL;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        clk_enable(host->clk);
        spdif_in_configure(host);
        spdif_in_format(host, host->saved_params.format);

        ctrl = readl(host->io_base + SPDIF_IN_CTRL);
        ctrl |= SPDIF_IN_SAMPLE | SPDIF_IN_ENB;
        writel(ctrl, host->io_base + SPDIF_IN_CTRL);
        writel(0xF, host->io_base + SPDIF_IN_IRQ_MASK);
        break;

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        ctrl = readl(host->io_base + SPDIF_IN_CTRL);
        ctrl &= ~(SPDIF_IN_SAMPLE | SPDIF_IN_ENB);
        writel(ctrl, host->io_base + SPDIF_IN_CTRL);
        writel(0x0, host->io_base + SPDIF_IN_IRQ_MASK);

        if (host->reset_perip)
            host->reset_perip();
        clk_disable(host->clk);
        break;

    default:
        ret = -EINVAL;
        break;
    }
    return ret;
}

static struct snd_soc_dai_ops spdif_in_dai_ops = {
    .startup    = spdif_in_startup,
    .shutdown   = spdif_in_shutdown,
    .trigger    = spdif_in_trigger,
    .hw_params  = spdif_in_hw_params,
};

struct snd_soc_dai_driver spdif_in_dai = {
    .capture = {
        .channels_min = 2,
        .channels_max = 2,
        .rates = (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \
                 SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 | \
                 SNDRV_PCM_RATE_192000),
        .formats = SNDRV_PCM_FMTBIT_S16_LE | \
               SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE,
    },
    .ops = &spdif_in_dai_ops,
};

static irqreturn_t spdif_in_irq(int irq, void *arg)
{
    struct spdif_in_dev *host = (struct spdif_in_dev *)arg;

    u32 irq_status = readl(host->io_base + SPDIF_IN_IRQ);

    if (!irq_status)
        return IRQ_NONE;

    if (irq_status & SPDIF_IRQ_FIFOWRITE)
        dev_err(host->dev, "spdif in: fifo write error");
    if (irq_status & SPDIF_IRQ_EMPTYFIFOREAD)
        dev_err(host->dev, "spdif in: empty fifo read error");
    if (irq_status & SPDIF_IRQ_FIFOFULL)
        dev_err(host->dev, "spdif in: fifo full error");
    if (irq_status & SPDIF_IRQ_OUTOFRANGE)
        dev_err(host->dev, "spdif in: out of range error");

    writel(0, host->io_base + SPDIF_IN_IRQ);

    return IRQ_HANDLED;
}

static int spdif_in_probe(struct platform_device *pdev)
{
    struct spdif_in_dev *host;
    struct spear_spdif_platform_data *pdata;
    struct resource *res, *res_fifo;
    int ret;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res)
        return -EINVAL;

    res_fifo = platform_get_resource(pdev, IORESOURCE_IO, 0);
    if (!res_fifo)
        return -EINVAL;

    if (!devm_request_mem_region(&pdev->dev, res->start,
                resource_size(res), pdev->name)) {
        dev_warn(&pdev->dev, "Failed to get memory resourse\n");
        return -ENOENT;
    }

    host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
    if (!host) {
        dev_warn(&pdev->dev, "kzalloc fail\n");
        return -ENOMEM;
    }

    host->io_base = devm_ioremap(&pdev->dev, res->start,
                resource_size(res));
    if (!host->io_base) {
        dev_warn(&pdev->dev, "ioremap failed\n");
        return -ENOMEM;
    }

    host->irq = platform_get_irq(pdev, 0);
    if (host->irq < 0)
        return -EINVAL;

    host->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(host->clk))
        return PTR_ERR(host->clk);

    pdata = dev_get_platdata(&pdev->dev);

    if (!pdata)
        return -EINVAL;

    host->dma_params.data = pdata->dma_params;
    host->dma_params.addr = res_fifo->start;
    host->dma_params.max_burst = 16;
    host->dma_params.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
    host->dma_params.filter = pdata->filter;
    host->reset_perip = pdata->reset_perip;

    host->dev = &pdev->dev;
    dev_set_drvdata(&pdev->dev, host);

    ret = devm_request_irq(&pdev->dev, host->irq, spdif_in_irq, 0,
            "spdif-in", host);
    if (ret) {
        clk_put(host->clk);
        dev_warn(&pdev->dev, "request_irq failed\n");
        return ret;
    }

    ret = snd_soc_register_dai(&pdev->dev, &spdif_in_dai);
    if (ret != 0) {
        clk_put(host->clk);
        return ret;
    }

    return 0;
}

static int spdif_in_remove(struct platform_device *pdev)
{
    struct spdif_in_dev *host = dev_get_drvdata(&pdev->dev);

    snd_soc_unregister_dai(&pdev->dev);
    dev_set_drvdata(&pdev->dev, NULL);

    clk_put(host->clk);

    return 0;
}


static struct platform_driver spdif_in_driver = {
    .probe      = spdif_in_probe,
    .remove     = spdif_in_remove,
    .driver     = {
        .name   = "spdif-in",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(spdif_in_driver);

MODULE_AUTHOR("Vipin Kumar <[email protected]>");
MODULE_DESCRIPTION("SPEAr SPDIF IN SoC Interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:spdif_in");