/*
 *  linux/drivers/mfd/mcp-sa11x0.c
 *
 *  Copyright (C) 2001-2005 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 *  SA11x0 MCP (Multimedia Communications Port) driver.
 *
 *  MCP read/write timeouts from Jordi Colomer, rehacked by rmk.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/platform_device.h>

#include <mach/dma.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/system.h>
#include <mach/mcp.h>

#include <mach/assabet.h>

#include "mcp.h"

struct mcp_sa11x0 {
        u32     mccr0;
        u32     mccr1;
};

#define priv(mcp)       ((struct mcp_sa11x0 *)mcp_priv(mcp))

static void
mcp_sa11x0_set_telecom_divisor(struct mcp *mcp, unsigned int divisor)
{
        unsigned int mccr0;

        divisor /= 32;

        mccr0 = Ser4MCCR0 & ~0x00007f00;
        mccr0 |= divisor << 8;
        Ser4MCCR0 = mccr0;
}

static void
mcp_sa11x0_set_audio_divisor(struct mcp *mcp, unsigned int divisor)
{
        unsigned int mccr0;

        divisor /= 32;

        mccr0 = Ser4MCCR0 & ~0x0000007f;
        mccr0 |= divisor;
        Ser4MCCR0 = mccr0;
}

/*
 * Write data to the device.  The bit should be set after 3 subframe
 * times (each frame is 64 clocks).  We wait a maximum of 6 subframes.
 * We really should try doing something more productive while we
 * wait.
 */
static void
mcp_sa11x0_write(struct mcp *mcp, unsigned int reg, unsigned int val)
{
        int ret = -ETIME;
        int i;

        Ser4MCDR2 = reg << 17 | MCDR2_Wr | (val & 0xffff);

        for (i = 0; i < 2; i++) {
                udelay(mcp->rw_timeout);
                if (Ser4MCSR & MCSR_CWC) {
                        ret = 0;
                        break;
                }
        }

        if (ret < 0)
                printk(KERN_WARNING "mcp: write timed out\n");
}

/*
 * Read data from the device.  The bit should be set after 3 subframe
 * times (each frame is 64 clocks).  We wait a maximum of 6 subframes.
 * We really should try doing something more productive while we
 * wait.
 */
static unsigned int
mcp_sa11x0_read(struct mcp *mcp, unsigned int reg)
{
        int ret = -ETIME;
        int i;

        Ser4MCDR2 = reg << 17 | MCDR2_Rd;

        for (i = 0; i < 2; i++) {
                udelay(mcp->rw_timeout);
                if (Ser4MCSR & MCSR_CRC) {
                        ret = Ser4MCDR2 & 0xffff;
                        break;
                }
        }

        if (ret < 0)
                printk(KERN_WARNING "mcp: read timed out\n");

        return ret;
}

static void mcp_sa11x0_enable(struct mcp *mcp)
{
        Ser4MCSR = -1;
        Ser4MCCR0 |= MCCR0_MCE;
}

static void mcp_sa11x0_disable(struct mcp *mcp)
{
        Ser4MCCR0 &= ~MCCR0_MCE;
}

/*
 * Our methods.
 */
static struct mcp_ops mcp_sa11x0 = {
        .set_telecom_divisor    = mcp_sa11x0_set_telecom_divisor,
        .set_audio_divisor      = mcp_sa11x0_set_audio_divisor,
        .reg_write              = mcp_sa11x0_write,
        .reg_read               = mcp_sa11x0_read,
        .enable                 = mcp_sa11x0_enable,
        .disable                = mcp_sa11x0_disable,
};

static int mcp_sa11x0_probe(struct platform_device *pdev)
{
        struct mcp_plat_data *data = pdev->dev.platform_data;
        struct mcp *mcp;
        int ret;

        if (!data)
                return -ENODEV;

        if (!request_mem_region(0x80060000, 0x60, "sa11x0-mcp"))
                return -EBUSY;

        mcp = mcp_host_alloc(&pdev->dev, sizeof(struct mcp_sa11x0));
        if (!mcp) {
                ret = -ENOMEM;
                goto release;
        }

        mcp->owner              = THIS_MODULE;
        mcp->ops                = &mcp_sa11x0;
        mcp->sclk_rate          = data->sclk_rate;
        mcp->dma_audio_rd       = DMA_Ser4MCP0Rd;
        mcp->dma_audio_wr       = DMA_Ser4MCP0Wr;
        mcp->dma_telco_rd       = DMA_Ser4MCP1Rd;
        mcp->dma_telco_wr       = DMA_Ser4MCP1Wr;

        platform_set_drvdata(pdev, mcp);

        if (machine_is_assabet()) {
                ASSABET_BCR_set(ASSABET_BCR_CODEC_RST);
        }

        /*
         * Setup the PPC unit correctly.
         */
        PPDR &= ~PPC_RXD4;
        PPDR |= PPC_TXD4 | PPC_SCLK | PPC_SFRM;
        PSDR |= PPC_RXD4;
        PSDR &= ~(PPC_TXD4 | PPC_SCLK | PPC_SFRM);
        PPSR &= ~(PPC_TXD4 | PPC_SCLK | PPC_SFRM);

        /*
         * Initialise device.  Note that we initially
         * set the sampling rate to minimum.
         */
        Ser4MCSR = -1;
        Ser4MCCR1 = data->mccr1;
        Ser4MCCR0 = data->mccr0 | 0x7f7f;

        /*
         * Calculate the read/write timeout (us) from the bit clock
         * rate.  This is the period for 3 64-bit frames.  Always
         * round this time up.
         */
        mcp->rw_timeout = (64 * 3 * 1000000 + mcp->sclk_rate - 1) /
                          mcp->sclk_rate;

        ret = mcp_host_register(mcp);
        if (ret == 0)
                goto out;

 release:
        release_mem_region(0x80060000, 0x60);
        platform_set_drvdata(pdev, NULL);

 out:
        return ret;
}

static int mcp_sa11x0_remove(struct platform_device *dev)
{
        struct mcp *mcp = platform_get_drvdata(dev);

        platform_set_drvdata(dev, NULL);
        mcp_host_unregister(mcp);
        release_mem_region(0x80060000, 0x60);

        return 0;
}

static int mcp_sa11x0_suspend(struct platform_device *dev, pm_message_t state)
{
        struct mcp *mcp = platform_get_drvdata(dev);

        priv(mcp)->mccr0 = Ser4MCCR0;
        priv(mcp)->mccr1 = Ser4MCCR1;
        Ser4MCCR0 &= ~MCCR0_MCE;

        return 0;
}

static int mcp_sa11x0_resume(struct platform_device *dev)
{
        struct mcp *mcp = platform_get_drvdata(dev);

        Ser4MCCR1 = priv(mcp)->mccr1;
        Ser4MCCR0 = priv(mcp)->mccr0;

        return 0;
}

/*
 * The driver for the SA11x0 MCP port.
 */
MODULE_ALIAS("platform:sa11x0-mcp");

static struct platform_driver mcp_sa11x0_driver = {
        .probe          = mcp_sa11x0_probe,
        .remove         = mcp_sa11x0_remove,
        .suspend        = mcp_sa11x0_suspend,
        .resume         = mcp_sa11x0_resume,
        .driver         = {
                .name   = "sa11x0-mcp",
        },
};

/*
 * This needs re-working
 */
static int __init mcp_sa11x0_init(void)
{
        return platform_driver_register(&mcp_sa11x0_driver);
}

static void __exit mcp_sa11x0_exit(void)
{
        platform_driver_unregister(&mcp_sa11x0_driver);
}

module_init(mcp_sa11x0_init);
module_exit(mcp_sa11x0_exit);

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("SA11x0 multimedia communications port driver");
MODULE_LICENSE("GPL");