omap-dmic.c

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/*
 * omap-dmic.c  --  OMAP ASoC DMIC DAI driver
 *
 * Copyright (C) 2010 - 2011 Texas Instruments
 *
 * Author: David Lambert <[email protected]>
 *     Misael Lopez Cruz <[email protected]>
 *     Liam Girdwood <[email protected]>
 *     Peter Ujfalusi <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/of_device.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>

#include "omap-pcm.h"
#include "omap-dmic.h"

struct omap_dmic {
    struct device *dev;
    void __iomem *io_base;
    struct clk *fclk;
    int fclk_freq;
    int out_freq;
    int clk_div;
    int sysclk;
    int threshold;
    u32 ch_enabled;
    bool active;
    struct mutex mutex;
};

/*
 * Stream DMA parameters
 */
static struct omap_pcm_dma_data omap_dmic_dai_dma_params = {
    .name       = "DMIC capture",
};

static inline void omap_dmic_write(struct omap_dmic *dmic, u16 reg, u32 val)
{
    __raw_writel(val, dmic->io_base + reg);
}

static inline int omap_dmic_read(struct omap_dmic *dmic, u16 reg)
{
    return __raw_readl(dmic->io_base + reg);
}

static inline void omap_dmic_start(struct omap_dmic *dmic)
{
    u32 ctrl = omap_dmic_read(dmic, OMAP_DMIC_CTRL_REG);

    /* Configure DMA controller */
    omap_dmic_write(dmic, OMAP_DMIC_DMAENABLE_SET_REG,
            OMAP_DMIC_DMA_ENABLE);

    omap_dmic_write(dmic, OMAP_DMIC_CTRL_REG, ctrl | dmic->ch_enabled);
}

static inline void omap_dmic_stop(struct omap_dmic *dmic)
{
    u32 ctrl = omap_dmic_read(dmic, OMAP_DMIC_CTRL_REG);
    omap_dmic_write(dmic, OMAP_DMIC_CTRL_REG,
            ctrl & ~OMAP_DMIC_UP_ENABLE_MASK);

    /* Disable DMA request generation */
    omap_dmic_write(dmic, OMAP_DMIC_DMAENABLE_CLR_REG,
            OMAP_DMIC_DMA_ENABLE);

}

static inline int dmic_is_enabled(struct omap_dmic *dmic)
{
    return omap_dmic_read(dmic, OMAP_DMIC_CTRL_REG) &
                        OMAP_DMIC_UP_ENABLE_MASK;
}

static int omap_dmic_dai_startup(struct snd_pcm_substream *substream,
                  struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);
    int ret = 0;

    mutex_lock(&dmic->mutex);

    if (!dai->active)
        dmic->active = 1;
    else
        ret = -EBUSY;

    mutex_unlock(&dmic->mutex);

    snd_soc_dai_set_dma_data(dai, substream, &omap_dmic_dai_dma_params);
    return ret;
}

static void omap_dmic_dai_shutdown(struct snd_pcm_substream *substream,
                    struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);

    mutex_lock(&dmic->mutex);

    if (!dai->active)
        dmic->active = 0;

    mutex_unlock(&dmic->mutex);
}

static int omap_dmic_select_divider(struct omap_dmic *dmic, int sample_rate)
{
    int divider = -EINVAL;

    /*
     * 192KHz rate is only supported with 19.2MHz/3.84MHz clock
     * configuration.
     */
    if (sample_rate == 192000) {
        if (dmic->fclk_freq == 19200000 && dmic->out_freq == 3840000)
            divider = 0x6; /* Divider: 5 (192KHz sampling rate) */
        else
            dev_err(dmic->dev,
                "invalid clock configuration for 192KHz\n");

        return divider;
    }

    switch (dmic->out_freq) {
    case 1536000:
        if (dmic->fclk_freq != 24576000)
            goto div_err;
        divider = 0x4; /* Divider: 16 */
        break;
    case 2400000:
        switch (dmic->fclk_freq) {
        case 12000000:
            divider = 0x5; /* Divider: 5 */
            break;
        case 19200000:
            divider = 0x0; /* Divider: 8 */
            break;
        case 24000000:
            divider = 0x2; /* Divider: 10 */
            break;
        default:
            goto div_err;
        }
        break;
    case 3072000:
        if (dmic->fclk_freq != 24576000)
            goto div_err;
        divider = 0x3; /* Divider: 8 */
        break;
    case 3840000:
        if (dmic->fclk_freq != 19200000)
            goto div_err;
        divider = 0x1; /* Divider: 5 (96KHz sampling rate) */
        break;
    default:
        dev_err(dmic->dev, "invalid out frequency: %dHz\n",
            dmic->out_freq);
        break;
    }

    return divider;

div_err:
    dev_err(dmic->dev, "invalid out frequency %dHz for %dHz input\n",
        dmic->out_freq, dmic->fclk_freq);
    return -EINVAL;
}

static int omap_dmic_dai_hw_params(struct snd_pcm_substream *substream,
                    struct snd_pcm_hw_params *params,
                    struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);
    struct omap_pcm_dma_data *dma_data;
    int channels;

    dmic->clk_div = omap_dmic_select_divider(dmic, params_rate(params));
    if (dmic->clk_div < 0) {
        dev_err(dmic->dev, "no valid divider for %dHz from %dHz\n",
            dmic->out_freq, dmic->fclk_freq);
        return -EINVAL;
    }

    dmic->ch_enabled = 0;
    channels = params_channels(params);
    switch (channels) {
    case 6:
        dmic->ch_enabled |= OMAP_DMIC_UP3_ENABLE;
    case 4:
        dmic->ch_enabled |= OMAP_DMIC_UP2_ENABLE;
    case 2:
        dmic->ch_enabled |= OMAP_DMIC_UP1_ENABLE;
        break;
    default:
        dev_err(dmic->dev, "invalid number of legacy channels\n");
        return -EINVAL;
    }

    /* packet size is threshold * channels */
    dma_data = snd_soc_dai_get_dma_data(dai, substream);
    dma_data->packet_size = dmic->threshold * channels;

    return 0;
}

static int omap_dmic_dai_prepare(struct snd_pcm_substream *substream,
                  struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);
    u32 ctrl;

    /* Configure uplink threshold */
    omap_dmic_write(dmic, OMAP_DMIC_FIFO_CTRL_REG, dmic->threshold);

    ctrl = omap_dmic_read(dmic, OMAP_DMIC_CTRL_REG);

    /* Set dmic out format */
    ctrl &= ~(OMAP_DMIC_FORMAT | OMAP_DMIC_POLAR_MASK);
    ctrl |= (OMAP_DMICOUTFORMAT_LJUST | OMAP_DMIC_POLAR1 |
         OMAP_DMIC_POLAR2 | OMAP_DMIC_POLAR3);

    /* Configure dmic clock divider */
    ctrl &= ~OMAP_DMIC_CLK_DIV_MASK;
    ctrl |= OMAP_DMIC_CLK_DIV(dmic->clk_div);

    omap_dmic_write(dmic, OMAP_DMIC_CTRL_REG, ctrl);

    omap_dmic_write(dmic, OMAP_DMIC_CTRL_REG,
            ctrl | OMAP_DMICOUTFORMAT_LJUST | OMAP_DMIC_POLAR1 |
            OMAP_DMIC_POLAR2 | OMAP_DMIC_POLAR3);

    return 0;
}

static int omap_dmic_dai_trigger(struct snd_pcm_substream *substream,
                  int cmd, struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        omap_dmic_start(dmic);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
        omap_dmic_stop(dmic);
        break;
    default:
        break;
    }

    return 0;
}

static int omap_dmic_select_fclk(struct omap_dmic *dmic, int clk_id,
                 unsigned int freq)
{
    struct clk *parent_clk;
    char *parent_clk_name;
    int ret = 0;

    switch (freq) {
    case 12000000:
    case 19200000:
    case 24000000:
    case 24576000:
        break;
    default:
        dev_err(dmic->dev, "invalid input frequency: %dHz\n", freq);
        dmic->fclk_freq = 0;
        return -EINVAL;
    }

    if (dmic->sysclk == clk_id) {
        dmic->fclk_freq = freq;
        return 0;
    }

    /* re-parent not allowed if a stream is ongoing */
    if (dmic->active && dmic_is_enabled(dmic)) {
        dev_err(dmic->dev, "can't re-parent when DMIC active\n");
        return -EBUSY;
    }

    switch (clk_id) {
    case OMAP_DMIC_SYSCLK_PAD_CLKS:
        parent_clk_name = "pad_clks_ck";
        break;
    case OMAP_DMIC_SYSCLK_SLIMBLUS_CLKS:
        parent_clk_name = "slimbus_clk";
        break;
    case OMAP_DMIC_SYSCLK_SYNC_MUX_CLKS:
        parent_clk_name = "dmic_sync_mux_ck";
        break;
    default:
        dev_err(dmic->dev, "fclk clk_id (%d) not supported\n", clk_id);
        return -EINVAL;
    }

    parent_clk = clk_get(dmic->dev, parent_clk_name);
    if (IS_ERR(parent_clk)) {
        dev_err(dmic->dev, "can't get %s\n", parent_clk_name);
        return -ENODEV;
    }

    mutex_lock(&dmic->mutex);
    if (dmic->active) {
        /* disable clock while reparenting */
        pm_runtime_put_sync(dmic->dev);
        ret = clk_set_parent(dmic->fclk, parent_clk);
        pm_runtime_get_sync(dmic->dev);
    } else {
        ret = clk_set_parent(dmic->fclk, parent_clk);
    }
    mutex_unlock(&dmic->mutex);

    if (ret < 0) {
        dev_err(dmic->dev, "re-parent failed\n");
        goto err_busy;
    }

    dmic->sysclk = clk_id;
    dmic->fclk_freq = freq;

err_busy:
    clk_put(parent_clk);

    return ret;
}

static int omap_dmic_select_outclk(struct omap_dmic *dmic, int clk_id,
                    unsigned int freq)
{
    int ret = 0;

    if (clk_id != OMAP_DMIC_ABE_DMIC_CLK) {
        dev_err(dmic->dev, "output clk_id (%d) not supported\n",
            clk_id);
        return -EINVAL;
    }

    switch (freq) {
    case 1536000:
    case 2400000:
    case 3072000:
    case 3840000:
        dmic->out_freq = freq;
        break;
    default:
        dev_err(dmic->dev, "invalid out frequency: %dHz\n", freq);
        dmic->out_freq = 0;
        ret = -EINVAL;
    }

    return ret;
}

static int omap_dmic_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
                    unsigned int freq, int dir)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);

    if (dir == SND_SOC_CLOCK_IN)
        return omap_dmic_select_fclk(dmic, clk_id, freq);
    else if (dir == SND_SOC_CLOCK_OUT)
        return omap_dmic_select_outclk(dmic, clk_id, freq);

    dev_err(dmic->dev, "invalid clock direction (%d)\n", dir);
    return -EINVAL;
}

static const struct snd_soc_dai_ops omap_dmic_dai_ops = {
    .startup    = omap_dmic_dai_startup,
    .shutdown   = omap_dmic_dai_shutdown,
    .hw_params  = omap_dmic_dai_hw_params,
    .prepare    = omap_dmic_dai_prepare,
    .trigger    = omap_dmic_dai_trigger,
    .set_sysclk = omap_dmic_set_dai_sysclk,
};

static int omap_dmic_probe(struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);

    pm_runtime_enable(dmic->dev);

    /* Disable lines while request is ongoing */
    pm_runtime_get_sync(dmic->dev);
    omap_dmic_write(dmic, OMAP_DMIC_CTRL_REG, 0x00);
    pm_runtime_put_sync(dmic->dev);

    /* Configure DMIC threshold value */
    dmic->threshold = OMAP_DMIC_THRES_MAX - 3;
    return 0;
}

static int omap_dmic_remove(struct snd_soc_dai *dai)
{
    struct omap_dmic *dmic = snd_soc_dai_get_drvdata(dai);

    pm_runtime_disable(dmic->dev);

    return 0;
}

static struct snd_soc_dai_driver omap_dmic_dai = {
    .name = "omap-dmic",
    .probe = omap_dmic_probe,
    .remove = omap_dmic_remove,
    .capture = {
        .channels_min = 2,
        .channels_max = 6,
        .rates = SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_192000,
        .formats = SNDRV_PCM_FMTBIT_S32_LE,
        .sig_bits = 24,
    },
    .ops = &omap_dmic_dai_ops,
};

static __devinit int asoc_dmic_probe(struct platform_device *pdev)
{
    struct omap_dmic *dmic;
    struct resource *res;
    int ret;

    dmic = devm_kzalloc(&pdev->dev, sizeof(struct omap_dmic), GFP_KERNEL);
    if (!dmic)
        return -ENOMEM;

    platform_set_drvdata(pdev, dmic);
    dmic->dev = &pdev->dev;
    dmic->sysclk = OMAP_DMIC_SYSCLK_SYNC_MUX_CLKS;

    mutex_init(&dmic->mutex);

    dmic->fclk = clk_get(dmic->dev, "fck");
    if (IS_ERR(dmic->fclk)) {
        dev_err(dmic->dev, "cant get fck\n");
        return -ENODEV;
    }

    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dma");
    if (!res) {
        dev_err(dmic->dev, "invalid dma memory resource\n");
        ret = -ENODEV;
        goto err_put_clk;
    }
    omap_dmic_dai_dma_params.port_addr = res->start + OMAP_DMIC_DATA_REG;

    res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
    if (!res) {
        dev_err(dmic->dev, "invalid dma resource\n");
        ret = -ENODEV;
        goto err_put_clk;
    }
    omap_dmic_dai_dma_params.dma_req = res->start;

    res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
    if (!res) {
        dev_err(dmic->dev, "invalid memory resource\n");
        ret = -ENODEV;
        goto err_put_clk;
    }

    if (!devm_request_mem_region(&pdev->dev, res->start,
                     resource_size(res), pdev->name)) {
        dev_err(dmic->dev, "memory region already claimed\n");
        ret = -ENODEV;
        goto err_put_clk;
    }

    dmic->io_base = devm_ioremap(&pdev->dev, res->start,
                     resource_size(res));
    if (!dmic->io_base) {
        ret = -ENOMEM;
        goto err_put_clk;
    }

    ret = snd_soc_register_dai(&pdev->dev, &omap_dmic_dai);
    if (ret)
        goto err_put_clk;

    return 0;

err_put_clk:
    clk_put(dmic->fclk);
    return ret;
}

static int __devexit asoc_dmic_remove(struct platform_device *pdev)
{
    struct omap_dmic *dmic = platform_get_drvdata(pdev);

    snd_soc_unregister_dai(&pdev->dev);
    clk_put(dmic->fclk);

    return 0;
}

static const struct of_device_id omap_dmic_of_match[] = {
    { .compatible = "ti,omap4-dmic", },
    { }
};
MODULE_DEVICE_TABLE(of, omap_dmic_of_match);

static struct platform_driver asoc_dmic_driver = {
    .driver = {
        .name = "omap-dmic",
        .owner = THIS_MODULE,
        .of_match_table = omap_dmic_of_match,
    },
    .probe = asoc_dmic_probe,
    .remove = __devexit_p(asoc_dmic_remove),
};

module_platform_driver(asoc_dmic_driver);

MODULE_ALIAS("platform:omap-dmic");
MODULE_AUTHOR("Peter Ujfalusi <[email protected]>");
MODULE_DESCRIPTION("OMAP DMIC ASoC Interface");
MODULE_LICENSE("GPL");