scoop.c

// 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(sizeof(struct scoop_dev), GFP_KERNEL);
	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);