// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/arch/arm/common/locomo.c
 *
 * Sharp LoCoMo support
 *
 * 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(struct irq_desc *desc)
{
        struct locomo *lchip = irq_desc_get_handler_data(desc);
        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) {
                unsigned int irq;

                /* 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_chained_handler_and_data(lchip->irq, locomo_handler, lchip);

        /* 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);
                irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
        }
}


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


/**
 *      locomo_probe - probe for a single LoCoMo chip.
 *      @phys_addr: physical address of device.
 *
 *      Probe for a LoCoMo chip.  This must be called
 *      before any other locomo-specific code.
 *
 *      Returns:
 *      %-ENODEV        device not found.
 *      %-EBUSY         physical address already marked in-use.
 *      %0              successful.
 */
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_and_data(lchip->irq, NULL, 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_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 void locomo_bus_remove(struct device *dev)
{
        struct locomo_dev *ldev = LOCOMO_DEV(dev);
        struct locomo_driver *drv = LOCOMO_DRV(dev->driver);

        if (drv->remove)
                drv->remove(ldev);
}

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

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 <lenz@cs.wisc.edu>");