// SPDX-License-Identifier: GPL-2.0-only
/*
 * Support code for the SCOOP interface found on various Sharp PDAs
 *
 * Copyright (c) 2004 Richard Purdie
 *
 *      Based on code written by Sharp/Lineo for 2.4 kernels
 */

#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/export.h>
#include <linux/io.h>
#include <asm/hardware/scoop.h>

/* PCMCIA to Scoop linkage

   There is no easy way to link multiple scoop devices into one
   single entity for the pxa2xx_pcmcia device so this structure
   is used which is setup by the platform code.

   This file is never modular so this symbol is always
   accessile to the board support files.
*/
struct scoop_pcmcia_config *platform_scoop_config;
EXPORT_SYMBOL(platform_scoop_config);

struct  scoop_dev {
        void __iomem *base;
        struct gpio_chip gpio;
        spinlock_t scoop_lock;
        unsigned short suspend_clr;
        unsigned short suspend_set;
        u32 scoop_gpwr;
};

void reset_scoop(struct device *dev)
{
        struct scoop_dev *sdev = dev_get_drvdata(dev);

        iowrite16(0x0100, sdev->base + SCOOP_MCR);  /* 00 */
        iowrite16(0x0000, sdev->base + SCOOP_CDR);  /* 04 */
        iowrite16(0x0000, sdev->base + SCOOP_CCR);  /* 10 */
        iowrite16(0x0000, sdev->base + SCOOP_IMR);  /* 18 */
        iowrite16(0x00FF, sdev->base + SCOOP_IRM);  /* 14 */
        iowrite16(0x0000, sdev->base + SCOOP_ISR);  /* 1C */
        iowrite16(0x0000, sdev->base + SCOOP_IRM);
}

static void __scoop_gpio_set(struct scoop_dev *sdev,
                        unsigned offset, int value)
{
        unsigned short gpwr;

        gpwr = ioread16(sdev->base + SCOOP_GPWR);
        if (value)
                gpwr |= 1 << (offset + 1);
        else
                gpwr &= ~(1 << (offset + 1));
        iowrite16(gpwr, sdev->base + SCOOP_GPWR);
}

static int scoop_gpio_set(struct gpio_chip *chip, unsigned int offset,
                          int value)
{
        struct scoop_dev *sdev = gpiochip_get_data(chip);
        unsigned long flags;

        spin_lock_irqsave(&sdev->scoop_lock, flags);

        __scoop_gpio_set(sdev, offset, value);

        spin_unlock_irqrestore(&sdev->scoop_lock, flags);

        return 0;
}

static int scoop_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct scoop_dev *sdev = gpiochip_get_data(chip);

        /* XXX: I'm unsure, but it seems so */
        return !!(ioread16(sdev->base + SCOOP_GPRR) & (1 << (offset + 1)));
}

static int scoop_gpio_direction_input(struct gpio_chip *chip,
                        unsigned offset)
{
        struct scoop_dev *sdev = gpiochip_get_data(chip);
        unsigned long flags;
        unsigned short gpcr;

        spin_lock_irqsave(&sdev->scoop_lock, flags);

        gpcr = ioread16(sdev->base + SCOOP_GPCR);
        gpcr &= ~(1 << (offset + 1));
        iowrite16(gpcr, sdev->base + SCOOP_GPCR);

        spin_unlock_irqrestore(&sdev->scoop_lock, flags);

        return 0;
}

static int scoop_gpio_direction_output(struct gpio_chip *chip,
                        unsigned offset, int value)
{
        struct scoop_dev *sdev = gpiochip_get_data(chip);
        unsigned long flags;
        unsigned short gpcr;

        spin_lock_irqsave(&sdev->scoop_lock, flags);

        __scoop_gpio_set(sdev, offset, value);

        gpcr = ioread16(sdev->base + SCOOP_GPCR);
        gpcr |= 1 << (offset + 1);
        iowrite16(gpcr, sdev->base + SCOOP_GPCR);

        spin_unlock_irqrestore(&sdev->scoop_lock, flags);

        return 0;
}

unsigned short read_scoop_reg(struct device *dev, unsigned short reg)
{
        struct scoop_dev *sdev = dev_get_drvdata(dev);
        return ioread16(sdev->base + reg);
}

void write_scoop_reg(struct device *dev, unsigned short reg, unsigned short data)
{
        struct scoop_dev *sdev = dev_get_drvdata(dev);
        iowrite16(data, sdev->base + reg);
}

EXPORT_SYMBOL(reset_scoop);
EXPORT_SYMBOL(read_scoop_reg);
EXPORT_SYMBOL(write_scoop_reg);

#ifdef CONFIG_PM
static void check_scoop_reg(struct scoop_dev *sdev)
{
        unsigned short mcr;

        mcr = ioread16(sdev->base + SCOOP_MCR);
        if ((mcr & 0x100) == 0)
                iowrite16(0x0101, sdev->base + SCOOP_MCR);
}

static int scoop_suspend(struct platform_device *dev, pm_message_t state)
{
        struct scoop_dev *sdev = platform_get_drvdata(dev);

        check_scoop_reg(sdev);
        sdev->scoop_gpwr = ioread16(sdev->base + SCOOP_GPWR);
        iowrite16((sdev->scoop_gpwr & ~sdev->suspend_clr) | sdev->suspend_set, sdev->base + SCOOP_GPWR);

        return 0;
}

static int scoop_resume(struct platform_device *dev)
{
        struct scoop_dev *sdev = platform_get_drvdata(dev);

        check_scoop_reg(sdev);
        iowrite16(sdev->scoop_gpwr, sdev->base + SCOOP_GPWR);

        return 0;
}
#else
#define scoop_suspend   NULL
#define scoop_resume    NULL
#endif

static int scoop_probe(struct platform_device *pdev)
{
        struct scoop_dev *devptr;
        struct scoop_config *inf;
        struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        int ret;

        if (!mem)
                return -EINVAL;

        devptr = kzalloc_obj(struct scoop_dev);
        if (!devptr)
                return -ENOMEM;

        spin_lock_init(&devptr->scoop_lock);

        inf = pdev->dev.platform_data;
        devptr->base = ioremap(mem->start, resource_size(mem));

        if (!devptr->base) {
                ret = -ENOMEM;
                goto err_ioremap;
        }

        platform_set_drvdata(pdev, devptr);

        printk("Sharp Scoop Device found at 0x%08x -> 0x%8p\n",(unsigned int)mem->start, devptr->base);

        iowrite16(0x0140, devptr->base + SCOOP_MCR);
        reset_scoop(&pdev->dev);
        iowrite16(0x0000, devptr->base + SCOOP_CPR);
        iowrite16(inf->io_dir & 0xffff, devptr->base + SCOOP_GPCR);
        iowrite16(inf->io_out & 0xffff, devptr->base + SCOOP_GPWR);

        devptr->suspend_clr = inf->suspend_clr;
        devptr->suspend_set = inf->suspend_set;

        devptr->gpio.base = -1;

        if (inf->gpio_base != 0) {
                devptr->gpio.label = dev_name(&pdev->dev);
                devptr->gpio.base = inf->gpio_base;
                devptr->gpio.ngpio = 12; /* PA11 = 0, PA12 = 1, etc. up to PA22 = 11 */
                devptr->gpio.set = scoop_gpio_set;
                devptr->gpio.get = scoop_gpio_get;
                devptr->gpio.direction_input = scoop_gpio_direction_input;
                devptr->gpio.direction_output = scoop_gpio_direction_output;

                ret = gpiochip_add_data(&devptr->gpio, devptr);
                if (ret)
                        goto err_gpio;
        }

        return 0;

err_gpio:
        platform_set_drvdata(pdev, NULL);
err_ioremap:
        iounmap(devptr->base);
        kfree(devptr);

        return ret;
}

static void scoop_remove(struct platform_device *pdev)
{
        struct scoop_dev *sdev = platform_get_drvdata(pdev);

        if (sdev->gpio.base != -1)
                gpiochip_remove(&sdev->gpio);

        platform_set_drvdata(pdev, NULL);
        iounmap(sdev->base);
        kfree(sdev);
}

static struct platform_driver scoop_driver = {
        .probe          = scoop_probe,
        .remove         = scoop_remove,
        .suspend        = scoop_suspend,
        .resume         = scoop_resume,
        .driver         = {
                .name   = "sharp-scoop",
        },
};

static int __init scoop_init(void)
{
        return platform_driver_register(&scoop_driver);
}

subsys_initcall(scoop_init);