/**
 * Freescale P1022RDK ALSA SoC Machine driver
 *
 * Author: Timur Tabi <timur@freescale.com>
 *
 * Copyright 2012 Freescale Semiconductor, Inc.
 *
 * 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.
 *
 * Note: in order for audio to work correctly, the output controls need
 * to be enabled, because they control the clock.  So for playback, for
 * example:
 *
 *      amixer sset 'Left Output Mixer PCM' on
 *      amixer sset 'Right Output Mixer PCM' on
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <sound/soc.h>
#include <asm/fsl_guts.h>

#include "fsl_dma.h"
#include "fsl_ssi.h"
#include "fsl_utils.h"

/* P1022-specific PMUXCR and DMUXCR bit definitions */

#define CCSR_GUTS_PMUXCR_UART0_I2C1_MASK        0x0001c000
#define CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI   0x00010000
#define CCSR_GUTS_PMUXCR_UART0_I2C1_SSI         0x00018000

#define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK       0x00000c00
#define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI        0x00000000

#define CCSR_GUTS_DMUXCR_PAD    1       /* DMA controller/channel set to pad */
#define CCSR_GUTS_DMUXCR_SSI    2       /* DMA controller/channel set to SSI */

/*
 * Set the DMACR register in the GUTS
 *
 * The DMACR register determines the source of initiated transfers for each
 * channel on each DMA controller.  Rather than have a bunch of repetitive
 * macros for the bit patterns, we just have a function that calculates
 * them.
 *
 * guts: Pointer to GUTS structure
 * co: The DMA controller (0 or 1)
 * ch: The channel on the DMA controller (0, 1, 2, or 3)
 * device: The device to set as the target (CCSR_GUTS_DMUXCR_xxx)
 */
static inline void guts_set_dmuxcr(struct ccsr_guts __iomem *guts,
        unsigned int co, unsigned int ch, unsigned int device)
{
        unsigned int shift = 16 + (8 * (1 - co) + 2 * (3 - ch));

        clrsetbits_be32(&guts->dmuxcr, 3 << shift, device << shift);
}

/* There's only one global utilities register */
static phys_addr_t guts_phys;

/**
 * machine_data: machine-specific ASoC device data
 *
 * This structure contains data for a single sound platform device on an
 * P1022 RDK.  Some of the data is taken from the device tree.
 */
struct machine_data {
        struct snd_soc_dai_link dai[2];
        struct snd_soc_card card;
        unsigned int dai_format;
        unsigned int codec_clk_direction;
        unsigned int cpu_clk_direction;
        unsigned int clk_frequency;
        unsigned int dma_id[2];         /* 0 = DMA1, 1 = DMA2, etc */
        unsigned int dma_channel_id[2]; /* 0 = ch 0, 1 = ch 1, etc*/
        char platform_name[2][DAI_NAME_SIZE]; /* One for each DMA channel */
};

/**
 * p1022_rdk_machine_probe: initialize the board
 *
 * This function is used to initialize the board-specific hardware.
 *
 * Here we program the DMACR and PMUXCR registers.
 */
static int p1022_rdk_machine_probe(struct snd_soc_card *card)
{
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);
        struct ccsr_guts __iomem *guts;

        guts = ioremap(guts_phys, sizeof(struct ccsr_guts));
        if (!guts) {
                dev_err(card->dev, "could not map global utilities\n");
                return -ENOMEM;
        }

        /* Enable SSI Tx signal */
        clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK,
                        CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI);

        /* Enable SSI Rx signal */
        clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK,
                        CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI);

        /* Enable DMA Channel for SSI */
        guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0],
                        CCSR_GUTS_DMUXCR_SSI);

        guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1],
                        CCSR_GUTS_DMUXCR_SSI);

        iounmap(guts);

        return 0;
}

/**
 * p1022_rdk_startup: program the board with various hardware parameters
 *
 * This function takes board-specific information, like clock frequencies
 * and serial data formats, and passes that information to the codec and
 * transport drivers.
 */
static int p1022_rdk_startup(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct machine_data *mdata =
                container_of(rtd->card, struct machine_data, card);
        struct device *dev = rtd->card->dev;
        int ret = 0;

        /* Tell the codec driver what the serial protocol is. */
        ret = snd_soc_dai_set_fmt(rtd->codec_dai, mdata->dai_format);
        if (ret < 0) {
                dev_err(dev, "could not set codec driver audio format (ret=%i)\n",
                        ret);
                return ret;
        }

        ret = snd_soc_dai_set_pll(rtd->codec_dai, 0, 0, mdata->clk_frequency,
                mdata->clk_frequency);
        if (ret < 0) {
                dev_err(dev, "could not set codec PLL frequency (ret=%i)\n",
                        ret);
                return ret;
        }

        return 0;
}

/**
 * p1022_rdk_machine_remove: Remove the sound device
 *
 * This function is called to remove the sound device for one SSI.  We
 * de-program the DMACR and PMUXCR register.
 */
static int p1022_rdk_machine_remove(struct snd_soc_card *card)
{
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);
        struct ccsr_guts __iomem *guts;

        guts = ioremap(guts_phys, sizeof(struct ccsr_guts));
        if (!guts) {
                dev_err(card->dev, "could not map global utilities\n");
                return -ENOMEM;
        }

        /* Restore the signal routing */
        clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK);
        clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK);
        guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0], 0);
        guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1], 0);

        iounmap(guts);

        return 0;
}

/**
 * p1022_rdk_ops: ASoC machine driver operations
 */
static struct snd_soc_ops p1022_rdk_ops = {
        .startup = p1022_rdk_startup,
};

/**
 * p1022_rdk_probe: platform probe function for the machine driver
 *
 * Although this is a machine driver, the SSI node is the "master" node with
 * respect to audio hardware connections.  Therefore, we create a new ASoC
 * device for each new SSI node that has a codec attached.
 */
static int p1022_rdk_probe(struct platform_device *pdev)
{
        struct device *dev = pdev->dev.parent;
        /* ssi_pdev is the platform device for the SSI node that probed us */
        struct platform_device *ssi_pdev =
                container_of(dev, struct platform_device, dev);
        struct device_node *np = ssi_pdev->dev.of_node;
        struct device_node *codec_np = NULL;
        struct machine_data *mdata;
        const u32 *iprop;
        int ret;

        /* Find the codec node for this SSI. */
        codec_np = of_parse_phandle(np, "codec-handle", 0);
        if (!codec_np) {
                dev_err(dev, "could not find codec node\n");
                return -EINVAL;
        }

        mdata = kzalloc(sizeof(struct machine_data), GFP_KERNEL);
        if (!mdata) {
                ret = -ENOMEM;
                goto error_put;
        }

        mdata->dai[0].cpu_dai_name = dev_name(&ssi_pdev->dev);
        mdata->dai[0].ops = &p1022_rdk_ops;

        /* ASoC core can match codec with device node */
        mdata->dai[0].codec_of_node = codec_np;

        /*
         * We register two DAIs per SSI, one for playback and the other for
         * capture.  We support codecs that have separate DAIs for both playback
         * and capture.
         */
        memcpy(&mdata->dai[1], &mdata->dai[0], sizeof(struct snd_soc_dai_link));

        /* The DAI names from the codec (snd_soc_dai_driver.name) */
        mdata->dai[0].codec_dai_name = "wm8960-hifi";
        mdata->dai[1].codec_dai_name = mdata->dai[0].codec_dai_name;

        /*
         * Configure the SSI for I2S slave mode.  Older device trees have
         * an fsl,mode property, but we ignore that since there's really
         * only one way to configure the SSI.
         */
        mdata->dai_format = SND_SOC_DAIFMT_NB_NF |
                SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM;
        mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
        mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;

        /*
         * In i2s-slave mode, the codec has its own clock source, so we
         * need to get the frequency from the device tree and pass it to
         * the codec driver.
         */
        iprop = of_get_property(codec_np, "clock-frequency", NULL);
        if (!iprop || !*iprop) {
                dev_err(&pdev->dev, "codec bus-frequency property is missing or invalid\n");
                ret = -EINVAL;
                goto error;
        }
        mdata->clk_frequency = be32_to_cpup(iprop);

        if (!mdata->clk_frequency) {
                dev_err(&pdev->dev, "unknown clock frequency\n");
                ret = -EINVAL;
                goto error;
        }

        /* Find the playback DMA channel to use. */
        mdata->dai[0].platform_name = mdata->platform_name[0];
        ret = fsl_asoc_get_dma_channel(np, "fsl,playback-dma", &mdata->dai[0],
                                       &mdata->dma_channel_id[0],
                                       &mdata->dma_id[0]);
        if (ret) {
                dev_err(&pdev->dev, "missing/invalid playback DMA phandle (ret=%i)\n",
                        ret);
                goto error;
        }

        /* Find the capture DMA channel to use. */
        mdata->dai[1].platform_name = mdata->platform_name[1];
        ret = fsl_asoc_get_dma_channel(np, "fsl,capture-dma", &mdata->dai[1],
                                       &mdata->dma_channel_id[1],
                                       &mdata->dma_id[1]);
        if (ret) {
                dev_err(&pdev->dev, "missing/invalid capture DMA phandle (ret=%i)\n",
                        ret);
                goto error;
        }

        /* Initialize our DAI data structure.  */
        mdata->dai[0].stream_name = "playback";
        mdata->dai[1].stream_name = "capture";
        mdata->dai[0].name = mdata->dai[0].stream_name;
        mdata->dai[1].name = mdata->dai[1].stream_name;

        mdata->card.probe = p1022_rdk_machine_probe;
        mdata->card.remove = p1022_rdk_machine_remove;
        mdata->card.name = pdev->name; /* The platform driver name */
        mdata->card.owner = THIS_MODULE;
        mdata->card.dev = &pdev->dev;
        mdata->card.num_links = 2;
        mdata->card.dai_link = mdata->dai;

        /* Register with ASoC */
        ret = snd_soc_register_card(&mdata->card);
        if (ret) {
                dev_err(&pdev->dev, "could not register card (ret=%i)\n", ret);
                goto error;
        }

        return 0;

error:
        kfree(mdata);
error_put:
        of_node_put(codec_np);
        return ret;
}

/**
 * p1022_rdk_remove: remove the platform device
 *
 * This function is called when the platform device is removed.
 */
static int p1022_rdk_remove(struct platform_device *pdev)
{
        struct snd_soc_card *card = platform_get_drvdata(pdev);
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);

        snd_soc_unregister_card(card);
        kfree(mdata);

        return 0;
}

static struct platform_driver p1022_rdk_driver = {
        .probe = p1022_rdk_probe,
        .remove = p1022_rdk_remove,
        .driver = {
                /*
                 * The name must match 'compatible' property in the device tree,
                 * in lowercase letters.
                 */
                .name = "snd-soc-p1022rdk",
                .owner = THIS_MODULE,
        },
};

/**
 * p1022_rdk_init: machine driver initialization.
 *
 * This function is called when this module is loaded.
 */
static int __init p1022_rdk_init(void)
{
        struct device_node *guts_np;
        struct resource res;

        /* Get the physical address of the global utilities registers */
        guts_np = of_find_compatible_node(NULL, NULL, "fsl,p1022-guts");
        if (of_address_to_resource(guts_np, 0, &res)) {
                pr_err("snd-soc-p1022rdk: missing/invalid global utils node\n");
                of_node_put(guts_np);
                return -EINVAL;
        }
        guts_phys = res.start;
        of_node_put(guts_np);

        return platform_driver_register(&p1022_rdk_driver);
}

/**
 * p1022_rdk_exit: machine driver exit
 *
 * This function is called when this driver is unloaded.
 */
static void __exit p1022_rdk_exit(void)
{
        platform_driver_unregister(&p1022_rdk_driver);
}

late_initcall(p1022_rdk_init);
module_exit(p1022_rdk_exit);

MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
MODULE_DESCRIPTION("Freescale / iVeia P1022 RDK ALSA SoC machine driver");
MODULE_LICENSE("GPL v2");