/**
 * Freescale P1022DS ALSA SoC Machine driver
 *
 * Author: Timur Tabi <timur@freescale.com>
 *
 * Copyright 2010 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.
 */

#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"

/* 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_85xx __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;

#define DAI_NAME_SIZE   32

/**
 * machine_data: machine-specific ASoC device data
 *
 * This structure contains data for a single sound platform device on an
 * P1022 DS.  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 ssi_id;            /* 0 = SSI1, 1 = SSI2, etc */
        unsigned int dma_id[2];         /* 0 = DMA1, 1 = DMA2, etc */
        unsigned int dma_channel_id[2]; /* 0 = ch 0, 1 = ch 1, etc*/
        char codec_name[DAI_NAME_SIZE];
        char platform_name[2][DAI_NAME_SIZE]; /* One for each DMA channel */
};

/**
 * p1022_ds_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_ds_machine_probe(struct platform_device *sound_device)
{
        struct snd_soc_card *card = platform_get_drvdata(sound_device);
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);
        struct ccsr_guts_85xx __iomem *guts;

        guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
        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_ds_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_ds_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\n");
                return ret;
        }

        /*
         * Tell the codec driver what the MCLK frequency is, and whether it's
         * a slave or master.
         */
        ret = snd_soc_dai_set_sysclk(rtd->codec_dai, 0, mdata->clk_frequency,
                                     mdata->codec_clk_direction);
        if (ret < 0) {
                dev_err(dev, "could not set codec driver clock params\n");
                return ret;
        }

        return 0;
}

/**
 * p1022_ds_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_ds_machine_remove(struct platform_device *sound_device)
{
        struct snd_soc_card *card = platform_get_drvdata(sound_device);
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);
        struct ccsr_guts_85xx __iomem *guts;

        guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
        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_ds_ops: ASoC machine driver operations
 */
static struct snd_soc_ops p1022_ds_ops = {
        .startup = p1022_ds_startup,
};

/**
 * get_node_by_phandle_name - get a node by its phandle name
 *
 * This function takes a node, the name of a property in that node, and a
 * compatible string.  Assuming the property is a phandle to another node,
 * it returns that node, (optionally) if that node is compatible.
 *
 * If the property is not a phandle, or the node it points to is not compatible
 * with the specific string, then NULL is returned.
 */
static struct device_node *get_node_by_phandle_name(struct device_node *np,
        const char *name, const char *compatible)
{
        np = of_parse_phandle(np, name, 0);
        if (!np)
                return NULL;

        if (!of_device_is_compatible(np, compatible)) {
                of_node_put(np);
                return NULL;
        }

        return np;
}

/**
 * get_parent_cell_index -- return the cell-index of the parent of a node
 *
 * Return the value of the cell-index property of the parent of the given
 * node.  This is used for DMA channel nodes that need to know the DMA ID
 * of the controller they are on.
 */
static int get_parent_cell_index(struct device_node *np)
{
        struct device_node *parent = of_get_parent(np);
        const u32 *iprop;
        int ret = -1;

        if (!parent)
                return -1;

        iprop = of_get_property(parent, "cell-index", NULL);
        if (iprop)
                ret = *iprop;

        of_node_put(parent);

        return ret;
}

/**
 * codec_node_dev_name - determine the dev_name for a codec node
 *
 * This function determines the dev_name for an I2C node.  This is the name
 * that would be returned by dev_name() if this device_node were part of a
 * 'struct device'  It's ugly and hackish, but it works.
 *
 * The dev_name for such devices include the bus number and I2C address. For
 * example, "cs4270-codec.0-004f".
 */
static int codec_node_dev_name(struct device_node *np, char *buf, size_t len)
{
        const u32 *iprop;
        int bus, addr;
        char temp[DAI_NAME_SIZE];

        of_modalias_node(np, temp, DAI_NAME_SIZE);

        iprop = of_get_property(np, "reg", NULL);
        if (!iprop)
                return -EINVAL;

        addr = *iprop;

        bus = get_parent_cell_index(np);
        if (bus < 0)
                return bus;

        snprintf(buf, len, "%s-codec.%u-%04x", temp, bus, addr);

        return 0;
}

static int get_dma_channel(struct device_node *ssi_np,
                           const char *compatible,
                           struct snd_soc_dai_link *dai,
                           unsigned int *dma_channel_id,
                           unsigned int *dma_id)
{
        struct resource res;
        struct device_node *dma_channel_np;
        const u32 *iprop;
        int ret;

        dma_channel_np = get_node_by_phandle_name(ssi_np, compatible,
                                                  "fsl,ssi-dma-channel");
        if (!dma_channel_np)
                return -EINVAL;

        /* Determine the dev_name for the device_node.  This code mimics the
         * behavior of of_device_make_bus_id(). We need this because ASoC uses
         * the dev_name() of the device to match the platform (DMA) device with
         * the CPU (SSI) device.  It's all ugly and hackish, but it works (for
         * now).
         *
         * dai->platform name should already point to an allocated buffer.
         */
        ret = of_address_to_resource(dma_channel_np, 0, &res);
        if (ret)
                return ret;
        snprintf((char *)dai->platform_name, DAI_NAME_SIZE, "%llx.%s",
                 (unsigned long long) res.start, dma_channel_np->name);

        iprop = of_get_property(dma_channel_np, "cell-index", NULL);
        if (!iprop) {
                of_node_put(dma_channel_np);
                return -EINVAL;
        }

        *dma_channel_id = *iprop;
        *dma_id = get_parent_cell_index(dma_channel_np);
        of_node_put(dma_channel_np);

        return 0;
}

/**
 * p1022_ds_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_ds_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 platform_device *sound_device = NULL;
        struct machine_data *mdata;
        int ret = -ENODEV;
        const char *sprop;
        const u32 *iprop;

        /* 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_ds_ops;

        /* Determine the codec name, it will be used as the codec DAI name */
        ret = codec_node_dev_name(codec_np, mdata->codec_name, DAI_NAME_SIZE);
        if (ret) {
                dev_err(&pdev->dev, "invalid codec node %s\n",
                        codec_np->full_name);
                ret = -EINVAL;
                goto error;
        }
        mdata->dai[0].codec_name = mdata->codec_name;

        /* 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 = "wm8776-hifi-playback";
        mdata->dai[1].codec_dai_name = "wm8776-hifi-capture";

        /* Get the device ID */
        iprop = of_get_property(np, "cell-index", NULL);
        if (!iprop) {
                dev_err(&pdev->dev, "cell-index property not found\n");
                ret = -EINVAL;
                goto error;
        }
        mdata->ssi_id = *iprop;

        /* Get the serial format and clock direction. */
        sprop = of_get_property(np, "fsl,mode", NULL);
        if (!sprop) {
                dev_err(&pdev->dev, "fsl,mode property not found\n");
                ret = -EINVAL;
                goto error;
        }

        if (strcasecmp(sprop, "i2s-slave") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_I2S;
                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 = *iprop;
        } else if (strcasecmp(sprop, "i2s-master") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_I2S;
                mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
        } else if (strcasecmp(sprop, "lj-slave") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
                mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
        } else if (strcasecmp(sprop, "lj-master") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
                mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
        } else if (strcasecmp(sprop, "rj-slave") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
                mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
        } else if (strcasecmp(sprop, "rj-master") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
                mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
        } else if (strcasecmp(sprop, "ac97-slave") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_AC97;
                mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
        } else if (strcasecmp(sprop, "ac97-master") == 0) {
                mdata->dai_format = SND_SOC_DAIFMT_AC97;
                mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
                mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
        } else {
                dev_err(&pdev->dev,
                        "unrecognized fsl,mode property '%s'\n", sprop);
                ret = -EINVAL;
                goto error;
        }

        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 = 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\n");
                goto error;
        }

        /* Find the capture DMA channel to use. */
        mdata->dai[1].platform_name = mdata->platform_name[1];
        ret = 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\n");
                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_ds_machine_probe;
        mdata->card.remove = p1022_ds_machine_remove;
        mdata->card.name = pdev->name; /* The platform driver name */
        mdata->card.num_links = 2;
        mdata->card.dai_link = mdata->dai;

        /* Allocate a new audio platform device structure */
        sound_device = platform_device_alloc("soc-audio", -1);
        if (!sound_device) {
                dev_err(&pdev->dev, "platform device alloc failed\n");
                ret = -ENOMEM;
                goto error;
        }

        /* Associate the card data with the sound device */
        platform_set_drvdata(sound_device, &mdata->card);

        /* Register with ASoC */
        ret = platform_device_add(sound_device);
        if (ret) {
                dev_err(&pdev->dev, "platform device add failed\n");
                goto error;
        }
        dev_set_drvdata(&pdev->dev, sound_device);

        of_node_put(codec_np);

        return 0;

error:
        if (sound_device)
                platform_device_unregister(sound_device);

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

/**
 * p1022_ds_remove: remove the platform device
 *
 * This function is called when the platform device is removed.
 */
static int __devexit p1022_ds_remove(struct platform_device *pdev)
{
        struct platform_device *sound_device = dev_get_drvdata(&pdev->dev);
        struct snd_soc_card *card = platform_get_drvdata(sound_device);
        struct machine_data *mdata =
                container_of(card, struct machine_data, card);

        platform_device_unregister(sound_device);

        kfree(mdata);
        sound_device->dev.platform_data = NULL;

        dev_set_drvdata(&pdev->dev, NULL);

        return 0;
}

static struct platform_driver p1022_ds_driver = {
        .probe = p1022_ds_probe,
        .remove = __devexit_p(p1022_ds_remove),
        .driver = {
                /* The name must match the 'model' property in the device tree,
                 * in lowercase letters, but only the part after that last
                 * comma.  This is because some model properties have a "fsl,"
                 * prefix.
                 */
                .name = "snd-soc-p1022",
                .owner = THIS_MODULE,
        },
};

/**
 * p1022_ds_init: machine driver initialization.
 *
 * This function is called when this module is loaded.
 */
static int __init p1022_ds_init(void)
{
        struct device_node *guts_np;
        struct resource res;

        pr_info("Freescale P1022 DS ALSA SoC machine driver\n");

        /* 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("p1022-ds: missing/invalid global utilities node\n");
                return -EINVAL;
        }
        guts_phys = res.start;
        of_node_put(guts_np);

        return platform_driver_register(&p1022_ds_driver);
}

/**
 * p1022_ds_exit: machine driver exit
 *
 * This function is called when this driver is unloaded.
 */
static void __exit p1022_ds_exit(void)
{
        platform_driver_unregister(&p1022_ds_driver);
}

module_init(p1022_ds_init);
module_exit(p1022_ds_exit);

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