/*
 * AD9834 SPI DAC driver
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/list.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <asm/div64.h>

#include "../iio.h"
#include "../sysfs.h"
#include "dds.h"

#include "ad9834.h"

static unsigned int ad9834_calc_freqreg(unsigned long mclk, unsigned long fout)
{
	unsigned long long freqreg = (u64) fout * (u64) (1 << AD9834_FREQ_BITS);
	do_div(freqreg, mclk);
	return freqreg;
}

static int ad9834_write_frequency(struct ad9834_state *st,
				  unsigned long addr, unsigned long fout)
{
	unsigned long regval;

	if (fout > (st->mclk / 2))
		return -EINVAL;

	regval = ad9834_calc_freqreg(st->mclk, fout);

	st->freq_data[0] = cpu_to_be16(addr | (regval &
				       RES_MASK(AD9834_FREQ_BITS / 2)));
	st->freq_data[1] = cpu_to_be16(addr | ((regval >>
				       (AD9834_FREQ_BITS / 2)) &
				       RES_MASK(AD9834_FREQ_BITS / 2)));

	return spi_sync(st->spi, &st->freq_msg);;
}

static int ad9834_write_phase(struct ad9834_state *st,
				  unsigned long addr, unsigned long phase)
{
	if (phase > (1 << AD9834_PHASE_BITS))
		return -EINVAL;
	st->data = cpu_to_be16(addr | phase);

	return spi_sync(st->spi, &st->msg);
}

static ssize_t ad9834_write(struct device *dev,
		struct device_attribute *attr,
		const char *buf,
		size_t len)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = dev_info->dev_data;
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int ret;
	long val;

	ret = strict_strtoul(buf, 10, &val);
	if (ret)
		goto error_ret;

	mutex_lock(&dev_info->mlock);
	switch (this_attr->address) {
	case AD9834_REG_FREQ0:
	case AD9834_REG_FREQ1:
		ret = ad9834_write_frequency(st, this_attr->address, val);
		break;
	case AD9834_REG_PHASE0:
	case AD9834_REG_PHASE1:
		ret = ad9834_write_phase(st, this_attr->address, val);
		break;
	case AD9834_OPBITEN:
		if (st->control & AD9834_MODE) {
			ret = -EINVAL;  /* AD9843 reserved mode */
			break;
		}

		if (val)
			st->control |= AD9834_OPBITEN;
		else
			st->control &= ~AD9834_OPBITEN;

		st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
		ret = spi_sync(st->spi, &st->msg);
		break;
	case AD9834_PIN_SW:
		if (val)
			st->control |= AD9834_PIN_SW;
		else
			st->control &= ~AD9834_PIN_SW;
		st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
		ret = spi_sync(st->spi, &st->msg);
		break;
	case AD9834_FSEL:
	case AD9834_PSEL:
		if (val == 0)
			st->control &= ~(this_attr->address | AD9834_PIN_SW);
		else if (val == 1) {
			st->control |= this_attr->address;
			st->control &= ~AD9834_PIN_SW;
		} else {
			ret = -EINVAL;
			break;
		}
		st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
		ret = spi_sync(st->spi, &st->msg);
		break;
	case AD9834_RESET:
		if (val)
			st->control &= ~AD9834_RESET;
		else
			st->control |= AD9834_RESET;

		st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
		ret = spi_sync(st->spi, &st->msg);
		break;
	default:
		ret = -ENODEV;
	}
	mutex_unlock(&dev_info->mlock);

error_ret:
	return ret ? ret : len;
}

static ssize_t ad9834_store_wavetype(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf,
				 size_t len)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = dev_info->dev_data;
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int ret = 0;
	bool is_ad9833 = st->devid == ID_AD9833;

	mutex_lock(&dev_info->mlock);

	switch (this_attr->address) {
	case 0:
		if (sysfs_streq(buf, "sine")) {
			st->control &= ~AD9834_MODE;
			if (is_ad9833)
				st->control &= ~AD9834_OPBITEN;
		} else if (sysfs_streq(buf, "triangle")) {
			if (is_ad9833) {
				st->control &= ~AD9834_OPBITEN;
				st->control |= AD9834_MODE;
			} else if (st->control & AD9834_OPBITEN) {
				ret = -EINVAL;	/* AD9843 reserved mode */
			} else {
				st->control |= AD9834_MODE;
			}
		} else if (is_ad9833 && sysfs_streq(buf, "square")) {
			st->control &= ~AD9834_MODE;
			st->control |= AD9834_OPBITEN;
		} else {
			ret = -EINVAL;
		}

		break;
	case 1:
		if (sysfs_streq(buf, "square") &&
			!(st->control & AD9834_MODE)) {
			st->control &= ~AD9834_MODE;
			st->control |= AD9834_OPBITEN;
		} else {
			ret = -EINVAL;
		}
		break;
	default:
		ret = -EINVAL;
		break;
	}

	if (!ret) {
		st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
		ret = spi_sync(st->spi, &st->msg);
	}
	mutex_unlock(&dev_info->mlock);

	return ret ? ret : len;
}

static ssize_t ad9834_show_name(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = iio_dev_get_devdata(dev_info);

	return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
}
static IIO_DEVICE_ATTR(name, S_IRUGO, ad9834_show_name, NULL, 0);

static ssize_t ad9834_show_out0_wavetype_available(struct device *dev,
						struct device_attribute *attr,
						char *buf)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = iio_dev_get_devdata(dev_info);
	char *str;

	if (st->devid == ID_AD9833)
		str = "sine triangle square";
	else if (st->control & AD9834_OPBITEN)
		str = "sine";
	else
		str = "sine triangle";

	return sprintf(buf, "%s\n", str);
}


static IIO_DEVICE_ATTR(dds0_out0_wavetype_available, S_IRUGO,
		       ad9834_show_out0_wavetype_available, NULL, 0);

static ssize_t ad9834_show_out1_wavetype_available(struct device *dev,
						struct device_attribute *attr,
						char *buf)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = iio_dev_get_devdata(dev_info);
	char *str;

	if (st->control & AD9834_MODE)
		str = "";
	else
		str = "square";

	return sprintf(buf, "%s\n", str);
}

static IIO_DEVICE_ATTR(dds0_out1_wavetype_available, S_IRUGO,
		       ad9834_show_out1_wavetype_available, NULL, 0);

/**
 * see dds.h for further information
 */

static IIO_DEV_ATTR_FREQ(0, 0, S_IWUSR, NULL, ad9834_write, AD9834_REG_FREQ0);
static IIO_DEV_ATTR_FREQ(0, 1, S_IWUSR, NULL, ad9834_write, AD9834_REG_FREQ1);
static IIO_DEV_ATTR_FREQSYMBOL(0, S_IWUSR, NULL, ad9834_write, AD9834_FSEL);
static IIO_CONST_ATTR_FREQ_SCALE(0, "1"); /* 1Hz */

static IIO_DEV_ATTR_PHASE(0, 0, S_IWUSR, NULL, ad9834_write, AD9834_REG_PHASE0);
static IIO_DEV_ATTR_PHASE(0, 1, S_IWUSR, NULL, ad9834_write, AD9834_REG_PHASE1);
static IIO_DEV_ATTR_PHASESYMBOL(0, S_IWUSR, NULL, ad9834_write, AD9834_PSEL);
static IIO_CONST_ATTR_PHASE_SCALE(0, "0.0015339808"); /* 2PI/2^12 rad*/

static IIO_DEV_ATTR_PINCONTROL_EN(0, S_IWUSR, NULL,
	ad9834_write, AD9834_PIN_SW);
static IIO_DEV_ATTR_OUT_ENABLE(0, S_IWUSR, NULL, ad9834_write, AD9834_RESET);
static IIO_DEV_ATTR_OUTY_ENABLE(0, 1, S_IWUSR, NULL,
	ad9834_write, AD9834_OPBITEN);
static IIO_DEV_ATTR_OUT_WAVETYPE(0, 0, ad9834_store_wavetype, 0);
static IIO_DEV_ATTR_OUT_WAVETYPE(0, 1, ad9834_store_wavetype, 1);

static struct attribute *ad9834_attributes[] = {
	&iio_dev_attr_dds0_freq0.dev_attr.attr,
	&iio_dev_attr_dds0_freq1.dev_attr.attr,
	&iio_const_attr_dds0_freq_scale.dev_attr.attr,
	&iio_dev_attr_dds0_phase0.dev_attr.attr,
	&iio_dev_attr_dds0_phase1.dev_attr.attr,
	&iio_const_attr_dds0_phase_scale.dev_attr.attr,
	&iio_dev_attr_dds0_pincontrol_en.dev_attr.attr,
	&iio_dev_attr_dds0_freqsymbol.dev_attr.attr,
	&iio_dev_attr_dds0_phasesymbol.dev_attr.attr,
	&iio_dev_attr_dds0_out_enable.dev_attr.attr,
	&iio_dev_attr_dds0_out1_enable.dev_attr.attr,
	&iio_dev_attr_dds0_out0_wavetype.dev_attr.attr,
	&iio_dev_attr_dds0_out1_wavetype.dev_attr.attr,
	&iio_dev_attr_dds0_out0_wavetype_available.dev_attr.attr,
	&iio_dev_attr_dds0_out1_wavetype_available.dev_attr.attr,
	&iio_dev_attr_name.dev_attr.attr,
	NULL,
};

static mode_t ad9834_attr_is_visible(struct kobject *kobj,
				     struct attribute *attr, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct ad9834_state *st = iio_dev_get_devdata(dev_info);

	mode_t mode = attr->mode;

	if (st->devid == ID_AD9834)
		return mode;

	if ((attr == &iio_dev_attr_dds0_out1_enable.dev_attr.attr) ||
		(attr == &iio_dev_attr_dds0_out1_wavetype.dev_attr.attr) ||
		(attr ==
		&iio_dev_attr_dds0_out1_wavetype_available.dev_attr.attr))
		mode = 0;

	return mode;
}

static const struct attribute_group ad9834_attribute_group = {
	.attrs = ad9834_attributes,
	.is_visible = ad9834_attr_is_visible,
};

static int __devinit ad9834_probe(struct spi_device *spi)
{
	struct ad9834_platform_data *pdata = spi->dev.platform_data;
	struct ad9834_state *st;
	int ret;

	if (!pdata) {
		dev_dbg(&spi->dev, "no platform data?\n");
		return -ENODEV;
	}

	st = kzalloc(sizeof(*st), GFP_KERNEL);
	if (st == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	st->reg = regulator_get(&spi->dev, "vcc");
	if (!IS_ERR(st->reg)) {
		ret = regulator_enable(st->reg);
		if (ret)
			goto error_put_reg;
	}

	st->mclk = pdata->mclk;

	spi_set_drvdata(spi, st);

	st->spi = spi;
	st->devid = spi_get_device_id(spi)->driver_data;

	st->indio_dev = iio_allocate_device();
	if (st->indio_dev == NULL) {
		ret = -ENOMEM;
		goto error_disable_reg;
	}

	st->indio_dev->dev.parent = &spi->dev;
	st->indio_dev->attrs = &ad9834_attribute_group;
	st->indio_dev->dev_data = (void *) st;
	st->indio_dev->driver_module = THIS_MODULE;
	st->indio_dev->modes = INDIO_DIRECT_MODE;

	/* Setup default messages */

	st->xfer.tx_buf = &st->data;
	st->xfer.len = 2;

	spi_message_init(&st->msg);
	spi_message_add_tail(&st->xfer, &st->msg);

	st->freq_xfer[0].tx_buf = &st->freq_data[0];
	st->freq_xfer[0].len = 2;
	st->freq_xfer[0].cs_change = 1;
	st->freq_xfer[1].tx_buf = &st->freq_data[1];
	st->freq_xfer[1].len = 2;

	spi_message_init(&st->freq_msg);
	spi_message_add_tail(&st->freq_xfer[0], &st->freq_msg);
	spi_message_add_tail(&st->freq_xfer[1], &st->freq_msg);

	st->control = AD9834_B28 | AD9834_RESET;

	if (!pdata->en_div2)
		st->control |= AD9834_DIV2;

	if (!pdata->en_signbit_msb_out && (st->devid == ID_AD9834))
		st->control |= AD9834_SIGN_PIB;

	st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
	ret = spi_sync(st->spi, &st->msg);
	if (ret) {
		dev_err(&spi->dev, "device init failed\n");
		goto error_free_device;
	}

	ret = ad9834_write_frequency(st, AD9834_REG_FREQ0, pdata->freq0);
	if (ret)
		goto error_free_device;

	ret = ad9834_write_frequency(st, AD9834_REG_FREQ1, pdata->freq1);
	if (ret)
		goto error_free_device;

	ret = ad9834_write_phase(st, AD9834_REG_PHASE0, pdata->phase0);
	if (ret)
		goto error_free_device;

	ret = ad9834_write_phase(st, AD9834_REG_PHASE1, pdata->phase1);
	if (ret)
		goto error_free_device;

	ret = iio_device_register(st->indio_dev);
	if (ret)
		goto error_free_device;

	return 0;

error_free_device:
	iio_free_device(st->indio_dev);
error_disable_reg:
	if (!IS_ERR(st->reg))
		regulator_disable(st->reg);
error_put_reg:
	if (!IS_ERR(st->reg))
		regulator_put(st->reg);
	kfree(st);
error_ret:
	return ret;
}

static int __devexit ad9834_remove(struct spi_device *spi)
{
	struct ad9834_state *st = spi_get_drvdata(spi);

	iio_device_unregister(st->indio_dev);
	if (!IS_ERR(st->reg)) {
		regulator_disable(st->reg);
		regulator_put(st->reg);
	}
	kfree(st);
	return 0;
}

static const struct spi_device_id ad9834_id[] = {
	{"ad9833", ID_AD9833},
	{"ad9834", ID_AD9834},
	{}
};

static struct spi_driver ad9834_driver = {
	.driver = {
		.name	= "ad9834",
		.bus	= &spi_bus_type,
		.owner	= THIS_MODULE,
	},
	.probe		= ad9834_probe,
	.remove		= __devexit_p(ad9834_remove),
	.id_table	= ad9834_id,
};

static int __init ad9834_init(void)
{
	return spi_register_driver(&ad9834_driver);
}
module_init(ad9834_init);

static void __exit ad9834_exit(void)
{
	spi_unregister_driver(&ad9834_driver);
}
module_exit(ad9834_exit);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD9833/AD9834 DDS");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:ad9834");