#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/mfd/pcf50633/core.h>
#include <linux/mfd/pcf50633/adc.h>
#include <linux/mfd/pcf50633/rtc.h>
#include <linux/mfd/pcf50633/mbc.h>
#include <linux/mfd/pcf50633/input.h>
#include <linux/mfd/pcf50633/pmic.h>

/* Read a block of upto 32 regs  */
int pcf50633_read_block(struct pcf50633 *pcf , u8 reg,
					int nr_regs, u8 *data)
{
	int ret;

	mutex_lock(&pcf->lock);
	ret = i2c_smbus_read_i2c_block_data(pcf->i2c_client, reg,
							nr_regs, data);
	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_read_block);

/* Write a block of upto 32 regs  */
int pcf50633_write_block(struct pcf50633 *pcf , u8 reg,
					int nr_regs, u8 *data)
{
	int ret;

	mutex_lock(&pcf->lock);
	ret = i2c_smbus_write_i2c_block_data(pcf->i2c_client, reg,
							nr_regs, data);
	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_write_block);

u8 pcf50633_reg_read(struct pcf50633 *pcf, u8 reg)
{
	int ret;

	mutex_lock(&pcf->lock);
	ret = i2c_smbus_read_byte_data(pcf->i2c_client, reg);
	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_reg_read);

int pcf50633_reg_write(struct pcf50633 *pcf, u8 reg, u8 val)
{
	int ret;
	mutex_lock(&pcf->lock);
	ret = i2c_smbus_write_byte_data(pcf->i2c_client, reg, val);
	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_reg_write);

int pcf50633_reg_set_bit_mask(struct pcf50633 *pcf, u8 reg, u8 mask, u8 val)
{
	int ret;
	u8 tmp;

	val &= mask;

	mutex_lock(&pcf->lock);

	tmp = i2c_smbus_read_byte_data(pcf->i2c_client, reg);
	tmp &= ~mask;
	tmp |= val;
	ret = i2c_smbus_write_byte_data(pcf->i2c_client, reg, tmp);

	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_reg_set_bit_mask);

int pcf50633_reg_clear_bits(struct pcf50633 *pcf, u8 reg, u8 val)
{
	int ret;
	u8 tmp;

	mutex_lock(&pcf->lock);

	tmp = i2c_smbus_read_byte_data(pcf->i2c_client, reg);
	tmp &= ~val;
	ret = i2c_smbus_write_byte_data(pcf->i2c_client, reg, tmp);

	mutex_unlock(&pcf->lock);

	return ret;
}
EXPORT_SYMBOL(pcf50633_reg_clear_bits);

/* sysfs attributes */
static ssize_t show_dump_regs(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	struct pcf50633 *pcf = dev_get_drvdata(dev);
	u8 dump[16];
	int n, n1, idx = 0;
	char *buf1 = buf;
	static u8 address_no_read[] = { /* must be ascending */
		PCF50633_REG_INT1,
		PCF50633_REG_INT2,
		PCF50633_REG_INT3,
		PCF50633_REG_INT4,
		PCF50633_REG_INT5,
		0 /* terminator */
	};

	for (n = 0; n < 256; n += sizeof(dump)) {
		for (n1 = 0; n1 < sizeof(dump); n1++)
			if (n == address_no_read[idx]) {
				idx++;
				dump[n1] = 0x00;
			} else
				dump[n1] = pcf50633_reg_read(pcf, n + n1);

		hex_dump_to_buffer(dump, sizeof(dump), 16, 1, buf1, 128, 0);
		buf1 += strlen(buf1);
		*buf1++ = '\n';
		*buf1 = '\0';
	}

	return buf1 - buf;
}
static DEVICE_ATTR(dump_regs, 0400, show_dump_regs, NULL);

static ssize_t show_resume_reason(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct pcf50633 *pcf = dev_get_drvdata(dev);
	int n;

	n = sprintf(buf, "%02x%02x%02x%02x%02x\n",
				pcf->resume_reason[0],
				pcf->resume_reason[1],
				pcf->resume_reason[2],
				pcf->resume_reason[3],
				pcf->resume_reason[4]);

	return n;
}
static DEVICE_ATTR(resume_reason, 0400, show_resume_reason, NULL);

static struct attribute *pcf_sysfs_entries[] = {
	&dev_attr_dump_regs.attr,
	&dev_attr_resume_reason.attr,
	NULL,
};

static struct attribute_group pcf_attr_group = {
	.name	= NULL,			/* put in device directory */
	.attrs	= pcf_sysfs_entries,
};


static int pcf50633_irq_mask_set(struct pcf50633 *pcf, int irq, int mask)
{
	u8 reg, bits, tmp;
	int ret = 0, idx;

	idx = irq / 8;
	reg =  PCF50633_REG_INT1M + idx;
	bits = 1 << (irq % 8);

	mutex_lock(&pcf->lock);

	if (mask) {
		tmp = i2c_smbus_read_byte_data(pcf->i2c_client, reg);
		tmp |= bits;
		ret = i2c_smbus_write_byte_data(pcf->i2c_client, reg, tmp);

		pcf->mask_regs[idx] &= ~bits;
		pcf->mask_regs[idx] |= bits;
	} else {
		tmp = i2c_smbus_read_byte_data(pcf->i2c_client, reg);
		tmp &= ~bits;
		ret = i2c_smbus_write_byte_data(pcf->i2c_client, reg, tmp);

		pcf->mask_regs[idx] &= ~bits;
	}

	mutex_unlock(&pcf->lock);

	return 0;
}

int pcf50633_irq_mask(struct pcf50633 *pcf, int irq)
{
	dev_info(pcf->dev, "Masking IRQ %d\n", irq);

	return pcf50633_irq_mask_set(pcf, irq, 1);
}
EXPORT_SYMBOL(pcf50633_irq_mask);

int pcf50633_irq_unmask(struct pcf50633 *pcf, int irq)
{
	dev_info(pcf->dev, "Unmasking IRQ %d\n", irq);

	return pcf50633_irq_mask_set(pcf, irq, 0);
}
EXPORT_SYMBOL(pcf50633_irq_unmask);

int pcf50633_irq_mask_get(struct pcf50633 *pcf, int irq)
{
	u8 reg, bits;

	reg =  (irq / 8);
	bits = (1 << (irq % 8));

	return pcf->mask_regs[reg] & bits;
}
EXPORT_SYMBOL(pcf50633_irq_mask_get);

static void pcf50633_irq_call_handler(struct pcf50633 *pcf,
					int irq)
{
	if (pcf->irq_handler[irq].handler)
		pcf->irq_handler[irq].handler(pcf, irq,
					pcf->irq_handler[irq].data);
}

#define PCF50633_ONKEY1S_TIMEOUT 8

static void pcf50633_irq_worker(struct work_struct *work)
{
	struct pcf50633 *pcf;
	int ret, i, j;
	u8 pcf_int[5], chgstat;

	pcf = container_of(work, struct pcf50633, irq_work);

	/* Read the 5 INT regs in one transaction */
	ret = pcf50633_read_block(pcf, PCF50633_REG_INT1,
						sizeof(pcf_int), pcf_int);
	if (ret != sizeof(pcf_int)) {
		dev_info(pcf->dev, "Error reading INT registers\n");

		/* We don't have an option but to retry. Because if
		 * we don't, there won't be another interrupt edge.
		 */
		goto reschedule;
	}

	/* We immediately read the usb and adapter status. We thus make sure
	 * only of USBINS/USBREM and ADAPINS/ADPREM IRQ handlers are called */
	if (pcf_int[0] & (PCF50633_INT1_USBINS | PCF50633_INT1_USBREM)) {
		chgstat = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2);
		if (chgstat & (0x3 << 4))
			pcf_int[0] &= ~(1 << PCF50633_INT1_USBREM);
		else
			pcf_int[0] &= ~(1 << PCF50633_INT1_USBINS);
	}

	if (pcf_int[0] & (PCF50633_INT1_ADPINS | PCF50633_INT1_ADPREM)) {
		chgstat = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2);
		if (chgstat & (0x3 << 4))
			pcf_int[0] &= ~(1 << PCF50633_INT1_ADPREM);
		else
			pcf_int[0] &= ~(1 << PCF50633_INT1_ADPINS);
	}

	dev_info(pcf->dev, "INT1=0x%02x INT2=0x%02x INT3=0x%02x "
			"INT4=0x%02x INT5=0x%02x\n", pcf_int[0],
			pcf_int[1], pcf_int[2], pcf_int[3], pcf_int[4]);

	/* Some revisions of the chip don't have a 8s standby mode on
	 * ONKEY1S press. We try to manually do it in such cases. */

	if (pcf_int[0] & PCF50633_INT1_SECOND && pcf->onkey1s_held) {
		dev_info(pcf->dev, "ONKEY1S held for %d secs\n",
							pcf->onkey1s_held);
		if (pcf->onkey1s_held++ == PCF50633_ONKEY1S_TIMEOUT)
			if (pcf->pdata->force_shutdown)
				pcf->pdata->force_shutdown(pcf);
	}

	if (pcf_int[2] & PCF50633_INT3_ONKEY1S) {
		dev_info(pcf->dev, "ONKEY1S held\n");
		pcf->onkey1s_held = 1 ;

		/* Unmask IRQ_SECOND */
		pcf50633_reg_clear_bits(pcf, PCF50633_REG_INT1M,
						PCF50633_INT1_SECOND);

		/* Unmask IRQ_ONKEYR */
		pcf50633_reg_clear_bits(pcf, PCF50633_REG_INT1M,
						PCF50633_INT1_SECOND);
	}

	if (pcf_int[1] & PCF50633_INT2_ONKEYR & pcf->onkey1s_held) {
		pcf->onkey1s_held = 0;

		/* Mask SECOND and ONKEYR interrupts */
		if (pcf->mask_regs[0] & PCF50633_INT1_SECOND)
			pcf50633_reg_set_bit_mask(pcf,
					PCF50633_REG_INT1M,
					PCF50633_INT1_SECOND,
					PCF50633_INT1_SECOND);

		if (pcf->mask_regs[1] & PCF50633_INT2_ONKEYR)
			pcf50633_reg_set_bit_mask(pcf,
					PCF50633_REG_INT2M,
					PCF50633_INT2_ONKEYR,
					PCF50633_INT2_ONKEYR);
	}

	/* Have we just resumed ? */
	if (pcf->is_suspended) {

		pcf->is_suspended = 0;

		/* Set the resume reason filtering out non resumers */
		for (i = 0; i < ARRAY_SIZE(pcf_int); i++)
			pcf->resume_reason[i] = pcf_int[i] &
						pcf->pdata->resumers[i];

		/* Make sure we don't pass on any input events to
		 * userspace now */
		pcf_int[1] = 0;
	}

	/* Unset masked interrupts */
	for (i = 0; i < 5; i++)
		pcf_int[i] &= ~pcf->mask_regs[i];

	for (i = 0; i < ARRAY_SIZE(pcf_int); i++)
		for (j = 0; j < 8 ; j++)
			if (pcf_int[i] & (1 << j))
				pcf50633_irq_call_handler(pcf, (i * 8) + j);

	put_device(pcf->dev);

	return;
reschedule:
	schedule_work(&pcf->irq_work);

	/* Don't put_device here. Will be used when we are rescheduled */

	return;
}

static irqreturn_t pcf50633_irq(int irq, void *data)
{
	struct pcf50633 *pcf = data;

	get_device(pcf->dev);
	schedule_work(&pcf->irq_work);

	return IRQ_HANDLED;
}

static void
pcf50633_client_dev_register(struct pcf50633 *pcf, const char *name,
						struct platform_device **pdev)
{
	int ret;

	*pdev = platform_device_alloc(name, -1);

	if (!pdev) {
		dev_err(pcf->dev, "Falied to allocate %s\n", name);
		return;
	}

	(*pdev)->dev.parent = pcf->dev;
	platform_set_drvdata(*pdev, pcf);

	ret = platform_device_add(*pdev);
	if (ret != 0) {
		dev_err(pcf->dev, "Failed to register %s: %d\n", name, ret);
		platform_device_put(*pdev);
		*pdev = NULL;
	}
}

#ifdef CONFIG_PM
static int pcf50633_suspend(struct device *dev, pm_message_t state)
{
	struct pcf50633 *pcf;
	int ret, i;
	u8 res[5];

	pcf = dev_get_drvdata(dev);

	/* Make sure our interrupt handlers are not called
	 * henceforth */
	disable_irq(pcf->irq);

	/* Make sure that an IRQ worker has quit */
	cancel_work_sync(&pcf->irq_work);

	/* Save the masks */
	ret = pcf50633_read_block(pcf, PCF50633_REG_INT1M, 5,
					pcf->suspend_irq_masks);
	if (ret < 0)
		dev_err(pcf->dev, "error saving irq masks\n");

	/* Set interrupt masks. So that only those sources we want to wake
	 * us up can
	 */
	for (i = 0; i < 5; i++)
		res[i] = ~pcf->pdata->resumers[i];

	pcf50633_write_block(pcf, PCF50633_REG_INT1M, 5, &res[0]);

	pcf->is_suspended = 1;

	return 0;
}

static int pcf50633_resume(struct device *dev)
{
	struct pcf50633 *pcf;

	pcf = dev_get_drvdata(dev);

	/* Write the saved mask registers */
	pcf50633_write_block(pcf, PCF50633_REG_INT1M, 5,
					pcf->suspend_irq_masks);

	/* Clear any pending interrupts and set resume reason if any */
	pcf50633_irq_worker(&pcf->irq_work);

	enable_irq(pcf->irq);

	return 0;
}
#else
#define pcf50633_suspend NULL
#define pcf50633_resume NULL
#endif

static int pcf50633_probe(struct i2c_client *client,
				const struct i2c_device_id *ids)
{
	struct pcf50633 *pcf;
	struct pcf50633_platform_data *pdata;
	int i, ret = 0;
	int version, variant;
	u8 mbcs1;

	pdata = client->dev.platform_data;

	pcf = kzalloc(sizeof(*pcf), GFP_KERNEL);
	if (!pcf)
		return -ENOMEM;

	pcf->pdata = pdata;
	pdata->pcf = pcf;
	
	mutex_init(&pcf->lock);

	i2c_set_clientdata(client, pcf);
	pcf->dev = &client->dev;
	pcf->i2c_client = client;

	INIT_WORK(&pcf->irq_work, pcf50633_irq_worker);

	version = pcf50633_reg_read(pcf, 0);
	if (version < 0) {
		dev_err(pcf->dev, "Unable to probe pcf50633\n");
		kfree(pcf);
		return -ENODEV;
	}

	variant = pcf50633_reg_read(pcf, 1);
	if (version < 0) {
		dev_err(pcf->dev, "Unable to probe pcf50633\n");
		kfree(pcf);
		return -ENODEV;
	}

	dev_info(pcf->dev, "Probed device version %d variant %d\n",
							version, variant);

	/* Enable all inteerupts except RTC SECOND */
	pcf->mask_regs[0] = 0x80;
	pcf50633_reg_write(pcf, PCF50633_REG_INT1M, 0x80);

	pcf50633_reg_write(pcf, PCF50633_REG_INT2M, 0x00);
	pcf50633_reg_write(pcf, PCF50633_REG_INT3M, 0x00);
	pcf50633_reg_write(pcf, PCF50633_REG_INT4M, 0x00);
	pcf50633_reg_write(pcf, PCF50633_REG_INT5M, 0x00);

	pcf50633_client_dev_register(pcf, "pcf50633-input",
						&pcf->input.pdev);
	pcf50633_client_dev_register(pcf, "pcf50633-rtc",
						&pcf->rtc.pdev);
	pcf50633_client_dev_register(pcf, "pcf50633-mbc",
						&pcf->mbc.pdev);
	pcf50633_client_dev_register(pcf, "pcf50633-adc",
						&pcf->adc.pdev);
	pcf50633_client_dev_register(pcf, "pcf50633-gpio",
						&pcf->gpio.pdev);
	for (i = 0; i < PCF50633_NUM_REGULATORS; i++) {
		struct platform_device *pdev;

		pdev = platform_device_alloc("pcf50633-regltr", i);
		if (!pdev) {
			dev_err(pcf->dev, "Cannot create regulator\n");
			continue;
		}

		pdev->dev.parent = pcf->dev;
		pdev->dev.platform_data = &pdata->reg_init_data[i];
		pdev->dev.driver_data = pcf;
		pcf->pmic.pdev[i] = pdev;

		platform_device_add(pdev);
	}

	pcf->irq = client->irq;

	if (client->irq) {
		ret = request_irq(client->irq, pcf50633_irq,
				IRQF_TRIGGER_FALLING, "pcf50633", pcf);

		if (ret) {
			dev_err(pcf->dev, "Failed to request IRQ %d\n", ret);
			goto err;
		}
	} else {
		dev_err(pcf->dev, "No IRQ configured\n");
		goto err;
	}

	if (enable_irq_wake(client->irq) < 0)
		dev_err(pcf->dev, "IRQ %u cannot be enabled as wake-up source"
			"in this hardware revision", client->irq);

	/* Cold Intialization */
	mbcs1 = pcf50633_reg_read(pcf, PCF50633_REG_MBCS1);

	if (mbcs1 & 0x01)
		pcf50633_irq_call_handler(pcf, PCF50633_IRQ_USBINS);
	if (mbcs1 & 0x04)
		pcf50633_irq_call_handler(pcf, PCF50633_IRQ_ADPINS);

	ret = sysfs_create_group(&client->dev.kobj, &pcf_attr_group);
	if (ret)
		dev_err(pcf->dev, "error creating sysfs entries\n");

	if (pdata->probe_done)
		pdata->probe_done(pcf);

	return 0;

err:
	kfree(pcf);
	return ret;
}

static int pcf50633_remove(struct i2c_client *client)
{
	struct pcf50633 *pcf = i2c_get_clientdata(client);

	free_irq(pcf->irq, pcf);
	kfree(pcf);

	return 0;
}

static struct i2c_device_id pcf50633_id_table[] = {
	{"pcf50633", 0x73},
};

static struct i2c_driver pcf50633_driver = {
	.driver = {
		.name	= "pcf50633",
		.suspend = pcf50633_suspend,
		.resume	= pcf50633_resume,
	},
	.id_table = pcf50633_id_table,
	.probe = pcf50633_probe,
	.remove = pcf50633_remove,
};

static int __init pcf50633_init(void)
{
	return i2c_add_driver(&pcf50633_driver);
}

static void pcf50633_exit(void)
{
	i2c_del_driver(&pcf50633_driver);
}

MODULE_DESCRIPTION("I2C chip driver for NXP PCF50633 PMU");
MODULE_AUTHOR("Harald Welte <laforge@openmoko.org>");
MODULE_LICENSE("GPL");

module_init(pcf50633_init);
module_exit(pcf50633_exit);