/*
 * Copyright (C) 2007 Sascha Hauer, Pengutronix
 *               2009 Marc Kleine-Budde <mkl@pengutronix.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *
 */

#include <common.h>
#include <init.h>
#include <driver.h>
#include <xfuncs.h>
#include <errno.h>
#include <malloc.h>

#include <i2c/i2c.h>
#include <spi/spi.h>
#include <mfd/mc13xxx.h>

#define DRIVERNAME		"mc13xxx"

enum mc13xxx_mode {
	MC13XXX_MODE_I2C,
	MC13XXX_MODE_SPI,
};

struct mc13xxx {
	struct cdev			cdev;
	union {
		struct i2c_client	*client;
		struct spi_device	*spi;
	};
	enum mc13xxx_mode		mode;
	int				revision;
};

#define to_mc13xxx(a)		container_of(a, struct mc13xxx, cdev)

static struct mc13xxx *mc_dev;

struct mc13xxx *mc13xxx_get(void)
{
	return mc_dev;
}
EXPORT_SYMBOL(mc13xxx_get);

int mc13xxx_revision(struct mc13xxx *mc13xxx)
{
	return mc13xxx->revision;
}
EXPORT_SYMBOL(mc13xxx_revision);

#ifdef CONFIG_SPI
static int spi_rw(struct spi_device *spi, void * buf, size_t len)
{
	int ret;

	struct spi_transfer t = {
		.tx_buf = (const void *)buf,
		.rx_buf = buf,
		.len = len,
		.cs_change = 0,
		.delay_usecs = 0,
	};
	struct spi_message m;

	spi_message_init(&m);
	spi_message_add_tail(&t, &m);

	if ((ret = spi_sync(spi, &m)))
		return ret;
	return 0;
}

#define MXC_PMIC_REG_NUM(reg)	(((reg) & 0x3f) << 25)
#define MXC_PMIC_WRITE		(1 << 31)

static int mc13xxx_spi_reg_read(struct mc13xxx *mc13xxx, u8 reg, u32 *val)
{
	uint32_t buf;

	buf = MXC_PMIC_REG_NUM(reg);

	spi_rw(mc13xxx->spi, &buf, 4);

	*val = buf;

	return 0;
}

static int mc13xxx_spi_reg_write(struct mc13xxx *mc13xxx, u8 reg, u32 val)
{
	uint32_t buf = MXC_PMIC_REG_NUM(reg) | MXC_PMIC_WRITE | (val & 0xffffff);

	spi_rw(mc13xxx->spi, &buf, 4);

	return 0;
}
#endif

#ifdef CONFIG_I2C
static int mc13xxx_i2c_reg_read(struct mc13xxx *mc13xxx, u8 reg, u32 *val)
{
	u8 buf[3];
	int ret;

	ret = i2c_read_reg(mc13xxx->client, reg, buf, 3);
	*val = buf[0] << 16 | buf[1] << 8 | buf[2] << 0;

	return ret == 3 ? 0 : ret;
}

static int mc13xxx_i2c_reg_write(struct mc13xxx *mc13xxx, u8 reg, u32 val)
{
	u8 buf[] = {
		val >> 16,
		val >>  8,
		val >>  0,
	};
	int ret;

	ret = i2c_write_reg(mc13xxx->client, reg, buf, 3);

	return ret == 3 ? 0 : ret;
}
#endif

int mc13xxx_reg_write(struct mc13xxx *mc13xxx, u8 reg, u32 val)
{
#ifdef CONFIG_I2C
	if (mc13xxx->mode == MC13XXX_MODE_I2C)
		return mc13xxx_i2c_reg_write(mc13xxx, reg, val);
#endif
#ifdef CONFIG_SPI
	if (mc13xxx->mode == MC13XXX_MODE_SPI)
		return mc13xxx_spi_reg_write(mc13xxx, reg, val);
#endif
	return -EINVAL;
}
EXPORT_SYMBOL(mc13xxx_reg_write);

int mc13xxx_reg_read(struct mc13xxx *mc13xxx, u8 reg, u32 *val)
{
#ifdef CONFIG_I2C
	if (mc13xxx->mode == MC13XXX_MODE_I2C)
		return mc13xxx_i2c_reg_read(mc13xxx, reg, val);
#endif
#ifdef CONFIG_SPI
	if (mc13xxx->mode == MC13XXX_MODE_SPI)
		return mc13xxx_spi_reg_read(mc13xxx, reg, val);
#endif
	return -EINVAL;
}
EXPORT_SYMBOL(mc13xxx_reg_read);

int mc13xxx_set_bits(struct mc13xxx *mc13xxx, u8 reg, u32 mask, u32 val)
{
	u32 tmp;
	int err;

	err = mc13xxx_reg_read(mc13xxx, reg, &tmp);
	tmp = (tmp & ~mask) | val;

	if (!err)
		err = mc13xxx_reg_write(mc13xxx, reg, tmp);

	return err;
}
EXPORT_SYMBOL(mc13xxx_set_bits);

static ssize_t mc_read(struct cdev *cdev, void *_buf, size_t count, loff_t offset, ulong flags)
{
	struct mc13xxx *priv = to_mc13xxx(cdev);
	u32 *buf = _buf;
	size_t i = count >> 2;
	int err;

	offset >>= 2;

	while (i) {
		err = mc13xxx_reg_read(priv, offset, buf);
		if (err)
			return (ssize_t)err;
		buf++;
		i--;
		offset++;
	}

	return count;
}

static ssize_t mc_write(struct cdev *cdev, const void *_buf, size_t count, loff_t offset, ulong flags)
{
	struct mc13xxx *mc13xxx = to_mc13xxx(cdev);
	const u32 *buf = _buf;
	size_t i = count >> 2;
	int err;

	offset >>= 2;

	while (i) {
		err = mc13xxx_reg_write(mc13xxx, offset, *buf);
		if (err)
			return (ssize_t)err;
		buf++;
		i--;
		offset++;
	}

	return count;
}

static struct file_operations mc_fops = {
	.lseek	= dev_lseek_default,
	.read	= mc_read,
	.write	= mc_write,
};

struct mc13892_rev {
	u16	rev_id;
	int	rev;
	char	*revstr;
};

static struct mc13892_rev mc13892_revisions[] = {
	{ 0x01, MC13892_REVISION_1_0, "1.0" },
	{ 0x09, MC13892_REVISION_1_1, "1.1" },
	{ 0x0a, MC13892_REVISION_1_2, "1.2" },
	{ 0x10, MC13892_REVISION_2_0, "2.0" },
	{ 0x11, MC13892_REVISION_2_1, "2.1" },
	{ 0x18, MC13892_REVISION_3_0, "3.0" },
	{ 0x19, MC13892_REVISION_3_1, "3.1" },
	{ 0x1a, MC13892_REVISION_3_2, "3.2" },
	{ 0x02, MC13892_REVISION_3_2a, "3.2a" },
	{ 0x1b, MC13892_REVISION_3_3, "3.3" },
	{ 0x1d, MC13892_REVISION_3_5, "3.5" },
};

static int mc13xxx_query_revision(struct mc13xxx *mc13xxx)
{
	unsigned int rev_id;
	char *chipname, revstr[5];
	int rev, i;

	mc13xxx_reg_read(mc13xxx, MC13XXX_REG_IDENTIFICATION, &rev_id);

	/* Determine chip type by decode ICID bits */
	switch ((rev_id >> 6) & 0x7) {
	case 2:
		chipname = "MC13783";
		rev = (((rev_id & 0x18) >> 3) << 4) | (rev_id & 0x7);
		/* Ver 0.2 is actually 3.2a. Report as 3.2 */
		if (rev == 0x02) {
			rev = 0x32;
			strcpy(revstr, "3.2a");
		} else
			sprintf(revstr, "%d.%d", rev / 0x10, rev % 10);
		break;
	case 7:
		chipname = "MC13892";
		for (i = 0; i < ARRAY_SIZE(mc13892_revisions); i++)
			if ((rev_id & 0x1f) == mc13892_revisions[i].rev_id)
				break;

		if (i == ARRAY_SIZE(mc13892_revisions))
			return -EINVAL;

		rev = mc13892_revisions[i].rev;
		strcpy(revstr, mc13892_revisions[i].revstr);

		if (rev == MC13892_REVISION_2_0) {
			if ((rev_id >> 9) & 0x3) {
				rev = MC13892_REVISION_2_0a;
				strcpy(revstr, "2.0a");
			}
		}
		break;
	default:
		dev_info(mc_dev->cdev.dev, "No PMIC detected.\n");
		return -EINVAL;
	}

	dev_info(mc_dev->cdev.dev, "Found %s ID: 0x%06x [Rev: %s]\n",
			chipname, rev_id, revstr);

	mc13xxx->revision = rev;

	return rev;
}

static int mc_probe(struct device_d *dev, enum mc13xxx_mode mode)
{
	int rev;

	if (mc_dev)
		return -EBUSY;

	mc_dev = xzalloc(sizeof(struct mc13xxx));
	mc_dev->mode = mode;
	mc_dev->cdev.name = DRIVERNAME;
	if (mode == MC13XXX_MODE_I2C) {
		mc_dev->client = to_i2c_client(dev);
	}
	if (mode == MC13XXX_MODE_SPI) {
		mc_dev->spi = dev->type_data;
		mc_dev->spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
		mc_dev->spi->bits_per_word = 32;
		mc_dev->spi->max_speed_hz = 20000000;
	}
	mc_dev->cdev.size = 256;
	mc_dev->cdev.dev = dev;
	mc_dev->cdev.ops = &mc_fops;

	rev = mc13xxx_query_revision(mc_dev);
	if (rev < 0) {
		free(mc_dev);
		mc_dev = NULL;
		return -EINVAL;
	}

	devfs_create(&mc_dev->cdev);

	return 0;
}

static int mc_i2c_probe(struct device_d *dev)
{
	return mc_probe(dev, MC13XXX_MODE_I2C);
}

static int mc_spi_probe(struct device_d *dev)
{
	return mc_probe(dev, MC13XXX_MODE_SPI);
}

static struct driver_d mc_i2c_driver = {
	.name  = "mc13xxx-i2c",
	.probe = mc_i2c_probe,
};

static struct driver_d mc_spi_driver = {
	.name  = "mc13xxx-spi",
	.probe = mc_spi_probe,
};

static int mc_init(void)
{
        register_driver(&mc_i2c_driver);
        register_driver(&mc_spi_driver);
        return 0;
}

device_initcall(mc_init);