/*
 *
 * arch/arm/mach-u300/mmc.c
 *
 *
 * Copyright (C) 2009 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 *
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 * Author: Johan Lundin <johan.lundin@stericsson.com>
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
 */
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/mmc/host.h>
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/machine.h>
#include <linux/gpio.h>

#include <asm/mach/mmc.h>
#include "mmc.h"
#include "padmux.h"

struct mmci_card_event {
	struct input_dev *mmc_input;
	int mmc_inserted;
	struct work_struct workq;
	struct mmc_platform_data mmc0_plat_data;
};

static unsigned int mmc_status(struct device *dev)
{
	struct mmci_card_event *mmci_card = container_of(
		dev->platform_data,
		struct mmci_card_event, mmc0_plat_data);

	return mmci_card->mmc_inserted;
}

/*
 * Here follows a large chunk of code which will only be enabled if you
 * have both the AB3100 chip mounted and the MMC subsystem activated.
 */

static u32 mmc_translate_vdd(struct device *dev, unsigned int voltage)
{
	int v;

	/*
	 * MMC Spec:
	 * bit 7:	1.70 - 1.95V
	 * bit 8 - 14:	2.0 - 2.6V
	 * bit 15 - 23:	2.7 - 3.6V
	 *
	 * ab3100 voltages:
	 * 000 - 2.85V
	 * 001 - 2.75V
	 * 010 - 1.8V
	 * 011 - 1.5V
	 */
	switch (voltage) {
	case 8:
		v = 3;
		break;
	case 9:
	case 10:
	case 11:
	case 12:
	case 13:
	case 14:
	case 15:
		v = 1;
		break;
	case 16:
		v = 1;
		break;
	case 17:
	case 18:
	case 19:
	case 20:
	case 21:
	case 22:
	case 23:
	case 24:
		v = 0;
		break;
	default:
		v = 0;
		break;
	}

	/* PL180 voltage register bits */
	return v << 2;
}


static int mmci_callback(void *data)
{
	struct mmci_card_event *mmci_card = data;

	disable_irq_on_gpio_pin(U300_GPIO_PIN_MMC_CD);
	schedule_work(&mmci_card->workq);

	return 0;
}


static ssize_t gpio_show(struct device *dev, struct device_attribute *attr,
		  char *buf)
{
	struct mmci_card_event *mmci_card = container_of(
		dev->platform_data,
		struct mmci_card_event, mmc0_plat_data);


	return sprintf(buf, "%d\n", !mmci_card->mmc_inserted);
}

static DEVICE_ATTR(mmc_inserted, S_IRUGO, gpio_show, NULL);

static void _mmci_callback(struct work_struct *ws)
{

	struct mmci_card_event *mmci_card = container_of(
		ws,
		struct mmci_card_event, workq);

	mdelay(20);

	mmci_card->mmc_inserted = !!gpio_get_value(U300_GPIO_PIN_MMC_CD);

	input_report_switch(mmci_card->mmc_input, KEY_INSERT,
			    !mmci_card->mmc_inserted);
	input_sync(mmci_card->mmc_input);

	pr_debug("MMC/SD card was %s\n",
		 mmci_card->mmc_inserted ? "removed" : "inserted");

	enable_irq_on_gpio_pin(U300_GPIO_PIN_MMC_CD, !mmci_card->mmc_inserted);
}

int __devinit mmc_init(struct amba_device *adev)
{
	struct mmci_card_event *mmci_card;
	struct device *mmcsd_device = &adev->dev;
	struct pmx *pmx;
	int ret = 0;

	mmci_card = kzalloc(sizeof(struct mmci_card_event), GFP_KERNEL);
	if (!mmci_card)
		return -ENOMEM;

	/* Nominally 2.85V on our platform */
	mmci_card->mmc0_plat_data.ocr_mask = MMC_VDD_28_29;
	mmci_card->mmc0_plat_data.translate_vdd = mmc_translate_vdd;
	mmci_card->mmc0_plat_data.status = mmc_status;

	mmcsd_device->platform_data = (void *) &mmci_card->mmc0_plat_data;

	INIT_WORK(&mmci_card->workq, _mmci_callback);

	ret = gpio_request(U300_GPIO_PIN_MMC_CD, "MMC card detection");
	if (ret) {
		printk(KERN_CRIT "Could not allocate MMC card detection " \
		       "GPIO pin\n");
		goto out;
	}

	ret = gpio_direction_input(U300_GPIO_PIN_MMC_CD);
	if (ret) {
		printk(KERN_CRIT "Invalid GPIO pin requested\n");
		goto out;
	}

	ret = sysfs_create_file(&mmcsd_device->kobj,
			       &dev_attr_mmc_inserted.attr);
	if (ret)
		goto out;

	mmci_card->mmc_input = input_allocate_device();
	if (!mmci_card->mmc_input) {
		printk(KERN_CRIT "Could not allocate MMC input device\n");
		return -ENOMEM;
	}

	mmci_card->mmc_input->name = "MMC insert notification";
	mmci_card->mmc_input->id.bustype = BUS_HOST;
	mmci_card->mmc_input->id.vendor = 0;
	mmci_card->mmc_input->id.product = 0;
	mmci_card->mmc_input->id.version = 0x0100;
	mmci_card->mmc_input->dev.parent = mmcsd_device;
	input_set_capability(mmci_card->mmc_input, EV_SW, KEY_INSERT);

	/*
	 * Since this must always be compiled into the kernel, this input
	 * is never unregistered or free:ed.
	 */
	ret = input_register_device(mmci_card->mmc_input);
	if (ret) {
		input_free_device(mmci_card->mmc_input);
		goto out;
	}

	input_set_drvdata(mmci_card->mmc_input, mmci_card);

	/*
	 * Setup padmuxing for MMC. Since this must always be
	 * compiled into the kernel, pmx is never released.
	 */
	pmx = pmx_get(mmcsd_device, U300_APP_PMX_MMC_SETTING);

	if (IS_ERR(pmx))
		pr_warning("Could not get padmux handle\n");
	else {
		ret = pmx_activate(mmcsd_device, pmx);
		if (IS_ERR_VALUE(ret))
			pr_warning("Could not activate padmuxing\n");
	}

	ret = gpio_register_callback(U300_GPIO_PIN_MMC_CD, mmci_callback,
				     mmci_card);

	schedule_work(&mmci_card->workq);

	printk(KERN_INFO "Registered MMC insert/remove notification\n");
out:
	return ret;
}