/*
 * linux/sound/mpc5200-ac97.c -- AC97 support for the Freescale MPC52xx chip.
 *
 * Copyright (C) 2009 Jon Smirl, Digispeaker
 * Author: Jon Smirl <jonsmirl@gmail.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 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/delay.h>

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

#include <asm/time.h>
#include <asm/delay.h>
#include <asm/mpc52xx.h>
#include <asm/mpc52xx_psc.h>

#include "mpc5200_dma.h"
#include "mpc5200_psc_ac97.h"

#define DRV_NAME "mpc5200-psc-ac97"

/* ALSA only supports a single AC97 device so static is recommend here */
static struct psc_dma *psc_dma;

static unsigned short psc_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
{
        int status;
        unsigned int val;

        mutex_lock(&psc_dma->mutex);

        /* Wait for command send status zero = ready */
        status = spin_event_timeout(!(in_be16(&psc_dma->psc_regs->sr_csr.status) &
                                MPC52xx_PSC_SR_CMDSEND), 100, 0);
        if (status == 0) {
                pr_err("timeout on ac97 bus (rdy)\n");
                mutex_unlock(&psc_dma->mutex);
                return -ENODEV;
        }

        /* Force clear the data valid bit */
        in_be32(&psc_dma->psc_regs->ac97_data);

        /* Send the read */
        out_be32(&psc_dma->psc_regs->ac97_cmd, (1<<31) | ((reg & 0x7f) << 24));

        /* Wait for the answer */
        status = spin_event_timeout((in_be16(&psc_dma->psc_regs->sr_csr.status) &
                                MPC52xx_PSC_SR_DATA_VAL), 100, 0);
        if (status == 0) {
                pr_err("timeout on ac97 read (val) %x\n",
                                in_be16(&psc_dma->psc_regs->sr_csr.status));
                mutex_unlock(&psc_dma->mutex);
                return -ENODEV;
        }
        /* Get the data */
        val = in_be32(&psc_dma->psc_regs->ac97_data);
        if (((val >> 24) & 0x7f) != reg) {
                pr_err("reg echo error on ac97 read\n");
                mutex_unlock(&psc_dma->mutex);
                return -ENODEV;
        }
        val = (val >> 8) & 0xffff;

        mutex_unlock(&psc_dma->mutex);
        return (unsigned short) val;
}

static void psc_ac97_write(struct snd_ac97 *ac97,
                                unsigned short reg, unsigned short val)
{
        int status;

        mutex_lock(&psc_dma->mutex);

        /* Wait for command status zero = ready */
        status = spin_event_timeout(!(in_be16(&psc_dma->psc_regs->sr_csr.status) &
                                MPC52xx_PSC_SR_CMDSEND), 100, 0);
        if (status == 0) {
                pr_err("timeout on ac97 bus (write)\n");
                goto out;
        }
        /* Write data */
        out_be32(&psc_dma->psc_regs->ac97_cmd,
                        ((reg & 0x7f) << 24) | (val << 8));

 out:
        mutex_unlock(&psc_dma->mutex);
}

static void psc_ac97_warm_reset(struct snd_ac97 *ac97)
{
        struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;

        mutex_lock(&psc_dma->mutex);

        out_be32(&regs->sicr, psc_dma->sicr | MPC52xx_PSC_SICR_AWR);
        udelay(3);
        out_be32(&regs->sicr, psc_dma->sicr);

        mutex_unlock(&psc_dma->mutex);
}

static void psc_ac97_cold_reset(struct snd_ac97 *ac97)
{
        struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;

        mutex_lock(&psc_dma->mutex);
        dev_dbg(psc_dma->dev, "cold reset\n");

        mpc5200_psc_ac97_gpio_reset(psc_dma->id);

        /* Notify the PSC that a reset has occurred */
        out_be32(&regs->sicr, psc_dma->sicr | MPC52xx_PSC_SICR_ACRB);

        /* Re-enable RX and TX */
        out_8(&regs->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);

        mutex_unlock(&psc_dma->mutex);

        msleep(1);
        psc_ac97_warm_reset(ac97);
}

struct snd_ac97_bus_ops soc_ac97_ops = {
        .read           = psc_ac97_read,
        .write          = psc_ac97_write,
        .reset          = psc_ac97_cold_reset,
        .warm_reset     = psc_ac97_warm_reset,
};
EXPORT_SYMBOL_GPL(soc_ac97_ops);

static int psc_ac97_hw_analog_params(struct snd_pcm_substream *substream,
                                 struct snd_pcm_hw_params *params,
                                 struct snd_soc_dai *cpu_dai)
{
        struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(cpu_dai);
        struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);

        dev_dbg(psc_dma->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
                " periods=%i buffer_size=%i  buffer_bytes=%i channels=%i"
                " rate=%i format=%i\n",
                __func__, substream, params_period_size(params),
                params_period_bytes(params), params_periods(params),
                params_buffer_size(params), params_buffer_bytes(params),
                params_channels(params), params_rate(params),
                params_format(params));

        /* Determine the set of enable bits to turn on */
        s->ac97_slot_bits = (params_channels(params) == 1) ? 0x100 : 0x300;
        if (substream->pstr->stream != SNDRV_PCM_STREAM_CAPTURE)
                s->ac97_slot_bits <<= 16;
        return 0;
}

static int psc_ac97_hw_digital_params(struct snd_pcm_substream *substream,
                                 struct snd_pcm_hw_params *params,
                                 struct snd_soc_dai *cpu_dai)
{
        struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(cpu_dai);

        dev_dbg(psc_dma->dev, "%s(substream=%p)\n", __func__, substream);

        if (params_channels(params) == 1)
                out_be32(&psc_dma->psc_regs->ac97_slots, 0x01000000);
        else
                out_be32(&psc_dma->psc_regs->ac97_slots, 0x03000000);

        return 0;
}

static int psc_ac97_trigger(struct snd_pcm_substream *substream, int cmd,
                                                        struct snd_soc_dai *dai)
{
        struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(dai);
        struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                dev_dbg(psc_dma->dev, "AC97 START: stream=%i\n",
                        substream->pstr->stream);

                /* Set the slot enable bits */
                psc_dma->slots |= s->ac97_slot_bits;
                out_be32(&psc_dma->psc_regs->ac97_slots, psc_dma->slots);
                break;

        case SNDRV_PCM_TRIGGER_STOP:
                dev_dbg(psc_dma->dev, "AC97 STOP: stream=%i\n",
                        substream->pstr->stream);

                /* Clear the slot enable bits */
                psc_dma->slots &= ~(s->ac97_slot_bits);
                out_be32(&psc_dma->psc_regs->ac97_slots, psc_dma->slots);
                break;
        }
        return 0;
}

static int psc_ac97_probe(struct snd_soc_dai *cpu_dai)
{
        struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(cpu_dai);
        struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;

        /* Go */
        out_8(&regs->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
        return 0;
}

/* ---------------------------------------------------------------------
 * ALSA SoC Bindings
 *
 * - Digital Audio Interface (DAI) template
 * - create/destroy dai hooks
 */

/**
 * psc_ac97_dai_template: template CPU Digital Audio Interface
 */
static struct snd_soc_dai_ops psc_ac97_analog_ops = {
        .hw_params      = psc_ac97_hw_analog_params,
        .trigger        = psc_ac97_trigger,
};

static struct snd_soc_dai_ops psc_ac97_digital_ops = {
        .hw_params      = psc_ac97_hw_digital_params,
};

static struct snd_soc_dai_driver psc_ac97_dai[] = {
{
        .ac97_control = 1,
        .probe  = psc_ac97_probe,
        .playback = {
                .channels_min   = 1,
                .channels_max   = 6,
                .rates          = SNDRV_PCM_RATE_8000_48000,
                .formats = SNDRV_PCM_FMTBIT_S32_BE,
        },
        .capture = {
                .channels_min   = 1,
                .channels_max   = 2,
                .rates          = SNDRV_PCM_RATE_8000_48000,
                .formats = SNDRV_PCM_FMTBIT_S32_BE,
        },
        .ops = &psc_ac97_analog_ops,
},
{
        .ac97_control = 1,
        .playback = {
                .channels_min   = 1,
                .channels_max   = 2,
                .rates          = SNDRV_PCM_RATE_32000 | \
                        SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
                .formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE,
        },
        .ops = &psc_ac97_digital_ops,
} };



/* ---------------------------------------------------------------------
 * OF platform bus binding code:
 * - Probe/remove operations
 * - OF device match table
 */
static int __devinit psc_ac97_of_probe(struct platform_device *op,
                                      const struct of_device_id *match)
{
        int rc;
        struct snd_ac97 ac97;
        struct mpc52xx_psc __iomem *regs;

        rc = snd_soc_register_dais(&op->dev, psc_ac97_dai, ARRAY_SIZE(psc_ac97_dai));
        if (rc != 0) {
                dev_err(&op->dev, "Failed to register DAI\n");
                return rc;
        }

        psc_dma = dev_get_drvdata(&op->dev);
        regs = psc_dma->psc_regs;
        ac97.private_data = psc_dma;

        psc_dma->imr = 0;
        out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);

        /* Configure the serial interface mode to AC97 */
        psc_dma->sicr = MPC52xx_PSC_SICR_SIM_AC97 | MPC52xx_PSC_SICR_ENAC97;
        out_be32(&regs->sicr, psc_dma->sicr);

        /* No slots active */
        out_be32(&regs->ac97_slots, 0x00000000);

        return 0;
}

static int __devexit psc_ac97_of_remove(struct platform_device *op)
{
        snd_soc_unregister_dais(&op->dev, ARRAY_SIZE(psc_ac97_dai));
        return 0;
}

/* Match table for of_platform binding */
static struct of_device_id psc_ac97_match[] __devinitdata = {
        { .compatible = "fsl,mpc5200-psc-ac97", },
        { .compatible = "fsl,mpc5200b-psc-ac97", },
        {}
};
MODULE_DEVICE_TABLE(of, psc_ac97_match);

static struct of_platform_driver psc_ac97_driver = {
        .probe = psc_ac97_of_probe,
        .remove = __devexit_p(psc_ac97_of_remove),
        .driver = {
                .name = "mpc5200-psc-ac97",
                .owner = THIS_MODULE,
                .of_match_table = psc_ac97_match,
        },
};

/* ---------------------------------------------------------------------
 * Module setup and teardown; simply register the of_platform driver
 * for the PSC in AC97 mode.
 */
static int __init psc_ac97_init(void)
{
        return of_register_platform_driver(&psc_ac97_driver);
}
module_init(psc_ac97_init);

static void __exit psc_ac97_exit(void)
{
        of_unregister_platform_driver(&psc_ac97_driver);
}
module_exit(psc_ac97_exit);

MODULE_AUTHOR("Jon Smirl <jonsmirl@gmail.com>");
MODULE_DESCRIPTION("mpc5200 AC97 module");
MODULE_LICENSE("GPL");