locomo.c

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/*
 * linux/arch/arm/common/locomo.c
 *
 * Sharp LoCoMo support
 *
 * 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 file contains all generic LoCoMo support.
 *
 * All initialization functions provided here are intended to be called
 * from machine specific code with proper arguments when required.
 *
 * Based on sa1111.c
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/io.h>

#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mach/irq.h>

#include <asm/hardware/locomo.h>

/* LoCoMo Interrupts */
#define IRQ_LOCOMO_KEY      (0)
#define IRQ_LOCOMO_GPIO     (1)
#define IRQ_LOCOMO_LT       (2)
#define IRQ_LOCOMO_SPI      (3)

/* M62332 output channel selection */
#define M62332_EVR_CH   1   /* M62332 volume channel number  */
                /*   0 : CH.1 , 1 : CH. 2        */
/* DAC send data */
#define M62332_SLAVE_ADDR   0x4e    /* Slave address  */
#define M62332_W_BIT        0x00    /* W bit (0 only) */
#define M62332_SUB_ADDR     0x00    /* Sub address    */
#define M62332_A_BIT        0x00    /* A bit (0 only) */

/* DAC setup and hold times (expressed in us) */
#define DAC_BUS_FREE_TIME   5   /*   4.7 us */
#define DAC_START_SETUP_TIME    5   /*   4.7 us */
#define DAC_STOP_SETUP_TIME 4   /*   4.0 us */
#define DAC_START_HOLD_TIME 5   /*   4.7 us */
#define DAC_SCL_LOW_HOLD_TIME   5   /*   4.7 us */
#define DAC_SCL_HIGH_HOLD_TIME  4   /*   4.0 us */
#define DAC_DATA_SETUP_TIME 1   /*   250 ns */
#define DAC_DATA_HOLD_TIME  1   /*   300 ns */
#define DAC_LOW_SETUP_TIME  1   /*   300 ns */
#define DAC_HIGH_SETUP_TIME 1   /*  1000 ns */

/* the following is the overall data for the locomo chip */
struct locomo {
    struct device *dev;
    unsigned long phys;
    unsigned int irq;
    int irq_base;
    spinlock_t lock;
    void __iomem *base;
#ifdef CONFIG_PM
    void *saved_state;
#endif
};

struct locomo_dev_info {
    unsigned long   offset;
    unsigned long   length;
    unsigned int    devid;
    unsigned int    irq[1];
    const char *    name;
};

/* All the locomo devices.  If offset is non-zero, the mapbase for the
 * locomo_dev will be set to the chip base plus offset.  If offset is
 * zero, then the mapbase for the locomo_dev will be set to zero.  An
 * offset of zero means the device only uses GPIOs or other helper
 * functions inside this file */
static struct locomo_dev_info locomo_devices[] = {
    {
        .devid      = LOCOMO_DEVID_KEYBOARD,
        .irq        = { IRQ_LOCOMO_KEY },
        .name       = "locomo-keyboard",
        .offset     = LOCOMO_KEYBOARD,
        .length     = 16,
    },
    {
        .devid      = LOCOMO_DEVID_FRONTLIGHT,
        .irq        = {},
        .name       = "locomo-frontlight",
        .offset     = LOCOMO_FRONTLIGHT,
        .length     = 8,

    },
    {
        .devid      = LOCOMO_DEVID_BACKLIGHT,
        .irq        = {},
        .name       = "locomo-backlight",
        .offset     = LOCOMO_BACKLIGHT,
        .length     = 8,
    },
    {
        .devid      = LOCOMO_DEVID_AUDIO,
        .irq        = {},
        .name       = "locomo-audio",
        .offset     = LOCOMO_AUDIO,
        .length     = 4,
    },
    {
        .devid      = LOCOMO_DEVID_LED,
        .irq        = {},
        .name       = "locomo-led",
        .offset     = LOCOMO_LED,
        .length     = 8,
    },
    {
        .devid      = LOCOMO_DEVID_UART,
        .irq        = {},
        .name       = "locomo-uart",
        .offset     = 0,
        .length     = 0,
    },
    {
        .devid      = LOCOMO_DEVID_SPI,
        .irq        = {},
        .name       = "locomo-spi",
        .offset     = LOCOMO_SPI,
        .length     = 0x30,
    },
};

static void locomo_handler(unsigned int irq, struct irq_desc *desc)
{
    struct locomo *lchip = irq_get_chip_data(irq);
    int req, i;

    /* Acknowledge the parent IRQ */
    desc->irq_data.chip->irq_ack(&desc->irq_data);

    /* check why this interrupt was generated */
    req = locomo_readl(lchip->base + LOCOMO_ICR) & 0x0f00;

    if (req) {
        /* generate the next interrupt(s) */
        irq = lchip->irq_base;
        for (i = 0; i <= 3; i++, irq++) {
            if (req & (0x0100 << i)) {
                generic_handle_irq(irq);
            }

        }
    }
}

static void locomo_ack_irq(struct irq_data *d)
{
}

static void locomo_mask_irq(struct irq_data *d)
{
    struct locomo *lchip = irq_data_get_irq_chip_data(d);
    unsigned int r;
    r = locomo_readl(lchip->base + LOCOMO_ICR);
    r &= ~(0x0010 << (d->irq - lchip->irq_base));
    locomo_writel(r, lchip->base + LOCOMO_ICR);
}

static void locomo_unmask_irq(struct irq_data *d)
{
    struct locomo *lchip = irq_data_get_irq_chip_data(d);
    unsigned int r;
    r = locomo_readl(lchip->base + LOCOMO_ICR);
    r |= (0x0010 << (d->irq - lchip->irq_base));
    locomo_writel(r, lchip->base + LOCOMO_ICR);
}

static struct irq_chip locomo_chip = {
    .name       = "LOCOMO",
    .irq_ack    = locomo_ack_irq,
    .irq_mask   = locomo_mask_irq,
    .irq_unmask = locomo_unmask_irq,
};

static void locomo_setup_irq(struct locomo *lchip)
{
    int irq = lchip->irq_base;

    /*
     * Install handler for IRQ_LOCOMO_HW.
     */
    irq_set_irq_type(lchip->irq, IRQ_TYPE_EDGE_FALLING);
    irq_set_chip_data(lchip->irq, lchip);
    irq_set_chained_handler(lchip->irq, locomo_handler);

    /* Install handlers for IRQ_LOCOMO_* */
    for ( ; irq <= lchip->irq_base + 3; irq++) {
        irq_set_chip_and_handler(irq, &locomo_chip, handle_level_irq);
        irq_set_chip_data(irq, lchip);
        set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
    }
}


static void locomo_dev_release(struct device *_dev)
{
    struct locomo_dev *dev = LOCOMO_DEV(_dev);

    kfree(dev);
}

static int
locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)
{
    struct locomo_dev *dev;
    int ret;

    dev = kzalloc(sizeof(struct locomo_dev), GFP_KERNEL);
    if (!dev) {
        ret = -ENOMEM;
        goto out;
    }

    /*
     * If the parent device has a DMA mask associated with it,
     * propagate it down to the children.
     */
    if (lchip->dev->dma_mask) {
        dev->dma_mask = *lchip->dev->dma_mask;
        dev->dev.dma_mask = &dev->dma_mask;
    }

    dev_set_name(&dev->dev, "%s", info->name);
    dev->devid   = info->devid;
    dev->dev.parent  = lchip->dev;
    dev->dev.bus     = &locomo_bus_type;
    dev->dev.release = locomo_dev_release;
    dev->dev.coherent_dma_mask = lchip->dev->coherent_dma_mask;

    if (info->offset)
        dev->mapbase = lchip->base + info->offset;
    else
        dev->mapbase = 0;
    dev->length = info->length;

    dev->irq[0] = (lchip->irq_base == NO_IRQ) ?
            NO_IRQ : lchip->irq_base + info->irq[0];

    ret = device_register(&dev->dev);
    if (ret) {
 out:
        kfree(dev);
    }
    return ret;
}

#ifdef CONFIG_PM

struct locomo_save_data {
    u16 LCM_GPO;
    u16 LCM_SPICT;
    u16 LCM_GPE;
    u16 LCM_ASD;
    u16 LCM_SPIMD;
};

static int locomo_suspend(struct platform_device *dev, pm_message_t state)
{
    struct locomo *lchip = platform_get_drvdata(dev);
    struct locomo_save_data *save;
    unsigned long flags;

    save = kmalloc(sizeof(struct locomo_save_data), GFP_KERNEL);
    if (!save)
        return -ENOMEM;

    lchip->saved_state = save;

    spin_lock_irqsave(&lchip->lock, flags);

    save->LCM_GPO     = locomo_readl(lchip->base + LOCOMO_GPO); /* GPIO */
    locomo_writel(0x00, lchip->base + LOCOMO_GPO);
    save->LCM_SPICT   = locomo_readl(lchip->base + LOCOMO_SPI + LOCOMO_SPICT);  /* SPI */
    locomo_writel(0x40, lchip->base + LOCOMO_SPI + LOCOMO_SPICT);
    save->LCM_GPE     = locomo_readl(lchip->base + LOCOMO_GPE); /* GPIO */
    locomo_writel(0x00, lchip->base + LOCOMO_GPE);
    save->LCM_ASD     = locomo_readl(lchip->base + LOCOMO_ASD); /* ADSTART */
    locomo_writel(0x00, lchip->base + LOCOMO_ASD);
    save->LCM_SPIMD   = locomo_readl(lchip->base + LOCOMO_SPI + LOCOMO_SPIMD);  /* SPI */
    locomo_writel(0x3C14, lchip->base + LOCOMO_SPI + LOCOMO_SPIMD);

    locomo_writel(0x00, lchip->base + LOCOMO_PAIF);
    locomo_writel(0x00, lchip->base + LOCOMO_DAC);
    locomo_writel(0x00, lchip->base + LOCOMO_BACKLIGHT + LOCOMO_TC);

    if ((locomo_readl(lchip->base + LOCOMO_LED + LOCOMO_LPT0) & 0x88) && (locomo_readl(lchip->base + LOCOMO_LED + LOCOMO_LPT1) & 0x88))
        locomo_writel(0x00, lchip->base + LOCOMO_C32K);     /* CLK32 off */
    else
        /* 18MHz already enabled, so no wait */
        locomo_writel(0xc1, lchip->base + LOCOMO_C32K);     /* CLK32 on */

    locomo_writel(0x00, lchip->base + LOCOMO_TADC);     /* 18MHz clock off*/
    locomo_writel(0x00, lchip->base + LOCOMO_AUDIO + LOCOMO_ACC);           /* 22MHz/24MHz clock off */
    locomo_writel(0x00, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);          /* FL */

    spin_unlock_irqrestore(&lchip->lock, flags);

    return 0;
}

static int locomo_resume(struct platform_device *dev)
{
    struct locomo *lchip = platform_get_drvdata(dev);
    struct locomo_save_data *save;
    unsigned long r;
    unsigned long flags;

    save = lchip->saved_state;
    if (!save)
        return 0;

    spin_lock_irqsave(&lchip->lock, flags);

    locomo_writel(save->LCM_GPO, lchip->base + LOCOMO_GPO);
    locomo_writel(save->LCM_SPICT, lchip->base + LOCOMO_SPI + LOCOMO_SPICT);
    locomo_writel(save->LCM_GPE, lchip->base + LOCOMO_GPE);
    locomo_writel(save->LCM_ASD, lchip->base + LOCOMO_ASD);
    locomo_writel(save->LCM_SPIMD, lchip->base + LOCOMO_SPI + LOCOMO_SPIMD);

    locomo_writel(0x00, lchip->base + LOCOMO_C32K);
    locomo_writel(0x90, lchip->base + LOCOMO_TADC);

    locomo_writel(0, lchip->base + LOCOMO_KEYBOARD + LOCOMO_KSC);
    r = locomo_readl(lchip->base + LOCOMO_KEYBOARD + LOCOMO_KIC);
    r &= 0xFEFF;
    locomo_writel(r, lchip->base + LOCOMO_KEYBOARD + LOCOMO_KIC);
    locomo_writel(0x1, lchip->base + LOCOMO_KEYBOARD + LOCOMO_KCMD);

    spin_unlock_irqrestore(&lchip->lock, flags);

    lchip->saved_state = NULL;
    kfree(save);

    return 0;
}
#endif


static int
__locomo_probe(struct device *me, struct resource *mem, int irq)
{
    struct locomo_platform_data *pdata = me->platform_data;
    struct locomo *lchip;
    unsigned long r;
    int i, ret = -ENODEV;

    lchip = kzalloc(sizeof(struct locomo), GFP_KERNEL);
    if (!lchip)
        return -ENOMEM;

    spin_lock_init(&lchip->lock);

    lchip->dev = me;
    dev_set_drvdata(lchip->dev, lchip);

    lchip->phys = mem->start;
    lchip->irq = irq;
    lchip->irq_base = (pdata) ? pdata->irq_base : NO_IRQ;

    /*
     * Map the whole region.  This also maps the
     * registers for our children.
     */
    lchip->base = ioremap(mem->start, PAGE_SIZE);
    if (!lchip->base) {
        ret = -ENOMEM;
        goto out;
    }

    /* locomo initialize */
    locomo_writel(0, lchip->base + LOCOMO_ICR);
    /* KEYBOARD */
    locomo_writel(0, lchip->base + LOCOMO_KEYBOARD + LOCOMO_KIC);

    /* GPIO */
    locomo_writel(0, lchip->base + LOCOMO_GPO);
    locomo_writel((LOCOMO_GPIO(1) | LOCOMO_GPIO(2) | LOCOMO_GPIO(13) | LOCOMO_GPIO(14))
            , lchip->base + LOCOMO_GPE);
    locomo_writel((LOCOMO_GPIO(1) | LOCOMO_GPIO(2) | LOCOMO_GPIO(13) | LOCOMO_GPIO(14))
            , lchip->base + LOCOMO_GPD);
    locomo_writel(0, lchip->base + LOCOMO_GIE);

    /* Frontlight */
    locomo_writel(0, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);
    locomo_writel(0, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALD);

    /* Longtime timer */
    locomo_writel(0, lchip->base + LOCOMO_LTINT);
    /* SPI */
    locomo_writel(0, lchip->base + LOCOMO_SPI + LOCOMO_SPIIE);

    locomo_writel(6 + 8 + 320 + 30 - 10, lchip->base + LOCOMO_ASD);
    r = locomo_readl(lchip->base + LOCOMO_ASD);
    r |= 0x8000;
    locomo_writel(r, lchip->base + LOCOMO_ASD);

    locomo_writel(6 + 8 + 320 + 30 - 10 - 128 + 4, lchip->base + LOCOMO_HSD);
    r = locomo_readl(lchip->base + LOCOMO_HSD);
    r |= 0x8000;
    locomo_writel(r, lchip->base + LOCOMO_HSD);

    locomo_writel(128 / 8, lchip->base + LOCOMO_HSC);

    /* XON */
    locomo_writel(0x80, lchip->base + LOCOMO_TADC);
    udelay(1000);
    /* CLK9MEN */
    r = locomo_readl(lchip->base + LOCOMO_TADC);
    r |= 0x10;
    locomo_writel(r, lchip->base + LOCOMO_TADC);
    udelay(100);

    /* init DAC */
    r = locomo_readl(lchip->base + LOCOMO_DAC);
    r |= LOCOMO_DAC_SCLOEB | LOCOMO_DAC_SDAOEB;
    locomo_writel(r, lchip->base + LOCOMO_DAC);

    r = locomo_readl(lchip->base + LOCOMO_VER);
    printk(KERN_INFO "LoCoMo Chip: %lu%lu\n", (r >> 8), (r & 0xff));

    /*
     * The interrupt controller must be initialised before any
     * other device to ensure that the interrupts are available.
     */
    if (lchip->irq != NO_IRQ && lchip->irq_base != NO_IRQ)
        locomo_setup_irq(lchip);

    for (i = 0; i < ARRAY_SIZE(locomo_devices); i++)
        locomo_init_one_child(lchip, &locomo_devices[i]);
    return 0;

 out:
    kfree(lchip);
    return ret;
}

static int locomo_remove_child(struct device *dev, void *data)
{
    device_unregister(dev);
    return 0;
} 

static void __locomo_remove(struct locomo *lchip)
{
    device_for_each_child(lchip->dev, NULL, locomo_remove_child);

    if (lchip->irq != NO_IRQ) {
        irq_set_chained_handler(lchip->irq, NULL);
        irq_set_handler_data(lchip->irq, NULL);
    }

    iounmap(lchip->base);
    kfree(lchip);
}

static int locomo_probe(struct platform_device *dev)
{
    struct resource *mem;
    int irq;

    mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
    if (!mem)
        return -EINVAL;
    irq = platform_get_irq(dev, 0);
    if (irq < 0)
        return -ENXIO;

    return __locomo_probe(&dev->dev, mem, irq);
}

static int locomo_remove(struct platform_device *dev)
{
    struct locomo *lchip = platform_get_drvdata(dev);

    if (lchip) {
        __locomo_remove(lchip);
        platform_set_drvdata(dev, NULL);
    }

    return 0;
}

/*
 *  Not sure if this should be on the system bus or not yet.
 *  We really want some way to register a system device at
 *  the per-machine level, and then have this driver pick
 *  up the registered devices.
 */
static struct platform_driver locomo_device_driver = {
    .probe      = locomo_probe,
    .remove     = locomo_remove,
#ifdef CONFIG_PM
    .suspend    = locomo_suspend,
    .resume     = locomo_resume,
#endif
    .driver     = {
        .name   = "locomo",
    },
};

/*
 *  Get the parent device driver (us) structure
 *  from a child function device
 */
static inline struct locomo *locomo_chip_driver(struct locomo_dev *ldev)
{
    return (struct locomo *)dev_get_drvdata(ldev->dev.parent);
}

void locomo_gpio_set_dir(struct device *dev, unsigned int bits, unsigned int dir)
{
    struct locomo *lchip = dev_get_drvdata(dev);
    unsigned long flags;
    unsigned int r;

    if (!lchip)
        return;

    spin_lock_irqsave(&lchip->lock, flags);

    r = locomo_readl(lchip->base + LOCOMO_GPD);
    if (dir)
        r |= bits;
    else
        r &= ~bits;
    locomo_writel(r, lchip->base + LOCOMO_GPD);

    r = locomo_readl(lchip->base + LOCOMO_GPE);
    if (dir)
        r |= bits;
    else
        r &= ~bits;
    locomo_writel(r, lchip->base + LOCOMO_GPE);

    spin_unlock_irqrestore(&lchip->lock, flags);
}
EXPORT_SYMBOL(locomo_gpio_set_dir);

int locomo_gpio_read_level(struct device *dev, unsigned int bits)
{
    struct locomo *lchip = dev_get_drvdata(dev);
    unsigned long flags;
    unsigned int ret;

    if (!lchip)
        return -ENODEV;

    spin_lock_irqsave(&lchip->lock, flags);
    ret = locomo_readl(lchip->base + LOCOMO_GPL);
    spin_unlock_irqrestore(&lchip->lock, flags);

    ret &= bits;
    return ret;
}
EXPORT_SYMBOL(locomo_gpio_read_level);

int locomo_gpio_read_output(struct device *dev, unsigned int bits)
{
    struct locomo *lchip = dev_get_drvdata(dev);
    unsigned long flags;
    unsigned int ret;

    if (!lchip)
        return -ENODEV;

    spin_lock_irqsave(&lchip->lock, flags);
    ret = locomo_readl(lchip->base + LOCOMO_GPO);
    spin_unlock_irqrestore(&lchip->lock, flags);

    ret &= bits;
    return ret;
}
EXPORT_SYMBOL(locomo_gpio_read_output);

void locomo_gpio_write(struct device *dev, unsigned int bits, unsigned int set)
{
    struct locomo *lchip = dev_get_drvdata(dev);
    unsigned long flags;
    unsigned int r;

    if (!lchip)
        return;

    spin_lock_irqsave(&lchip->lock, flags);

    r = locomo_readl(lchip->base + LOCOMO_GPO);
    if (set)
        r |= bits;
    else
        r &= ~bits;
    locomo_writel(r, lchip->base + LOCOMO_GPO);

    spin_unlock_irqrestore(&lchip->lock, flags);
}
EXPORT_SYMBOL(locomo_gpio_write);

static void locomo_m62332_sendbit(void *mapbase, int bit)
{
    unsigned int r;

    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_DATA_HOLD_TIME); /* 300 nsec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */

    if (bit & 1) {
        r = locomo_readl(mapbase + LOCOMO_DAC);
        r |=  LOCOMO_DAC_SDAOEB;
        locomo_writel(r, mapbase + LOCOMO_DAC);
        udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    } else {
        r = locomo_readl(mapbase + LOCOMO_DAC);
        r &=  ~(LOCOMO_DAC_SDAOEB);
        locomo_writel(r, mapbase + LOCOMO_DAC);
        udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    }

    udelay(DAC_DATA_SETUP_TIME);    /* 250 nsec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /*  4.0 usec */
}

void locomo_m62332_senddata(struct locomo_dev *ldev, unsigned int dac_data, int channel)
{
    struct locomo *lchip = locomo_chip_driver(ldev);
    int i;
    unsigned char data;
    unsigned int r;
    void *mapbase = lchip->base;
    unsigned long flags;

    spin_lock_irqsave(&lchip->lock, flags);

    /* Start */
    udelay(DAC_BUS_FREE_TIME);  /* 5.0 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB | LOCOMO_DAC_SDAOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4.0 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SDAOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_START_HOLD_TIME);    /* 5.0 usec */
    udelay(DAC_DATA_HOLD_TIME); /* 300 nsec */

    /* Send slave address and W bit (LSB is W bit) */
    data = (M62332_SLAVE_ADDR << 1) | M62332_W_BIT;
    for (i = 1; i <= 8; i++) {
        locomo_m62332_sendbit(mapbase, data >> (8 - i));
    }

    /* Check A bit */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SDAOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4.7 usec */
    if (locomo_readl(mapbase + LOCOMO_DAC) & LOCOMO_DAC_SDAOEB) {   /* High is error */
        printk(KERN_WARNING "locomo: m62332_senddata Error 1\n");
        goto out;
    }

    /* Send Sub address (LSB is channel select) */
    /*    channel = 0 : ch1 select              */
    /*            = 1 : ch2 select              */
    data = M62332_SUB_ADDR + channel;
    for (i = 1; i <= 8; i++) {
        locomo_m62332_sendbit(mapbase, data >> (8 - i));
    }

    /* Check A bit */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SDAOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4.7 usec */
    if (locomo_readl(mapbase + LOCOMO_DAC) & LOCOMO_DAC_SDAOEB) {   /* High is error */
        printk(KERN_WARNING "locomo: m62332_senddata Error 2\n");
        goto out;
    }

    /* Send DAC data */
    for (i = 1; i <= 8; i++) {
        locomo_m62332_sendbit(mapbase, dac_data >> (8 - i));
    }

    /* Check A bit */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SDAOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4.7 usec */
    if (locomo_readl(mapbase + LOCOMO_DAC) & LOCOMO_DAC_SDAOEB) {   /* High is error */
        printk(KERN_WARNING "locomo: m62332_senddata Error 3\n");
    }

out:
    /* stop */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r &=  ~(LOCOMO_DAC_SCLOEB);
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 300 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4 usec */
    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SDAOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_HIGH_SETUP_TIME);    /* 1000 nsec */
    udelay(DAC_SCL_HIGH_HOLD_TIME); /* 4 usec */

    r = locomo_readl(mapbase + LOCOMO_DAC);
    r |=  LOCOMO_DAC_SCLOEB | LOCOMO_DAC_SDAOEB;
    locomo_writel(r, mapbase + LOCOMO_DAC);
    udelay(DAC_LOW_SETUP_TIME); /* 1000 nsec */
    udelay(DAC_SCL_LOW_HOLD_TIME);  /* 4.7 usec */

    spin_unlock_irqrestore(&lchip->lock, flags);
}
EXPORT_SYMBOL(locomo_m62332_senddata);

/*
 *  Frontlight control
 */

void locomo_frontlight_set(struct locomo_dev *dev, int duty, int vr, int bpwf)
{
    unsigned long flags;
    struct locomo *lchip = locomo_chip_driver(dev);

    if (vr)
        locomo_gpio_write(dev->dev.parent, LOCOMO_GPIO_FL_VR, 1);
    else
        locomo_gpio_write(dev->dev.parent, LOCOMO_GPIO_FL_VR, 0);

    spin_lock_irqsave(&lchip->lock, flags);
    locomo_writel(bpwf, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);
    udelay(100);
    locomo_writel(duty, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALD);
    locomo_writel(bpwf | LOCOMO_ALC_EN, lchip->base + LOCOMO_FRONTLIGHT + LOCOMO_ALS);
    spin_unlock_irqrestore(&lchip->lock, flags);
}
EXPORT_SYMBOL(locomo_frontlight_set);

/*
 *  LoCoMo "Register Access Bus."
 *
 *  We model this as a regular bus type, and hang devices directly
 *  off this.
 */
static int locomo_match(struct device *_dev, struct device_driver *_drv)
{
    struct locomo_dev *dev = LOCOMO_DEV(_dev);
    struct locomo_driver *drv = LOCOMO_DRV(_drv);

    return dev->devid == drv->devid;
}

static int locomo_bus_suspend(struct device *dev, pm_message_t state)
{
    struct locomo_dev *ldev = LOCOMO_DEV(dev);
    struct locomo_driver *drv = LOCOMO_DRV(dev->driver);
    int ret = 0;

    if (drv && drv->suspend)
        ret = drv->suspend(ldev, state);
    return ret;
}

static int locomo_bus_resume(struct device *dev)
{
    struct locomo_dev *ldev = LOCOMO_DEV(dev);
    struct locomo_driver *drv = LOCOMO_DRV(dev->driver);
    int ret = 0;

    if (drv && drv->resume)
        ret = drv->resume(ldev);
    return ret;
}

static int locomo_bus_probe(struct device *dev)
{
    struct locomo_dev *ldev = LOCOMO_DEV(dev);
    struct locomo_driver *drv = LOCOMO_DRV(dev->driver);
    int ret = -ENODEV;

    if (drv->probe)
        ret = drv->probe(ldev);
    return ret;
}

static int locomo_bus_remove(struct device *dev)
{
    struct locomo_dev *ldev = LOCOMO_DEV(dev);
    struct locomo_driver *drv = LOCOMO_DRV(dev->driver);
    int ret = 0;

    if (drv->remove)
        ret = drv->remove(ldev);
    return ret;
}

struct bus_type locomo_bus_type = {
    .name       = "locomo-bus",
    .match      = locomo_match,
    .probe      = locomo_bus_probe,
    .remove     = locomo_bus_remove,
    .suspend    = locomo_bus_suspend,
    .resume     = locomo_bus_resume,
};

int locomo_driver_register(struct locomo_driver *driver)
{
    driver->drv.bus = &locomo_bus_type;
    return driver_register(&driver->drv);
}
EXPORT_SYMBOL(locomo_driver_register);

void locomo_driver_unregister(struct locomo_driver *driver)
{
    driver_unregister(&driver->drv);
}
EXPORT_SYMBOL(locomo_driver_unregister);

static int __init locomo_init(void)
{
    int ret = bus_register(&locomo_bus_type);
    if (ret == 0)
        platform_driver_register(&locomo_device_driver);
    return ret;
}

static void __exit locomo_exit(void)
{
    platform_driver_unregister(&locomo_device_driver);
    bus_unregister(&locomo_bus_type);
}

module_init(locomo_init);
module_exit(locomo_exit);

MODULE_DESCRIPTION("Sharp LoCoMo core driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Lenz <[email protected]>");