[linux-2.6-block.git] / drivers / hwmon / max1111.c

/*
 * max1111.c - +2.7V, Low-Power, Multichannel, Serial 8-bit ADCs
 *
 * Based on arch/arm/mach-pxa/corgi_ssp.c
 *
 * Copyright (C) 2004-2005 Richard Purdie
 *
 * Copyright (C) 2008 Marvell International Ltd.
 *	Eric Miao <eric.miao@marvell.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  publishhed by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>

#define MAX1111_TX_BUF_SIZE	1
#define MAX1111_RX_BUF_SIZE	2

/* MAX1111 Commands */
#define MAX1111_CTRL_PD0      (1u << 0)
#define MAX1111_CTRL_PD1      (1u << 1)
#define MAX1111_CTRL_SGL      (1u << 2)
#define MAX1111_CTRL_UNI      (1u << 3)
#define MAX1111_CTRL_SEL_SH   (5)	/* NOTE: bit 4 is ignored */
#define MAX1111_CTRL_STR      (1u << 7)

struct max1111_data {
	struct spi_device	*spi;
	struct device		*hwmon_dev;
	struct spi_message	msg;
	struct spi_transfer	xfer[2];
	uint8_t tx_buf[MAX1111_TX_BUF_SIZE];
	uint8_t rx_buf[MAX1111_RX_BUF_SIZE];
	struct mutex		drvdata_lock;
	/* protect msg, xfer and buffers from multiple access */
};

static int max1111_read(struct device *dev, int channel)
{
	struct max1111_data *data = dev_get_drvdata(dev);
	uint8_t v1, v2;
	int err;

	/* writing to drvdata struct is not thread safe, wait on mutex */
	mutex_lock(&data->drvdata_lock);

	data->tx_buf[0] = (channel << MAX1111_CTRL_SEL_SH) |
		MAX1111_CTRL_PD0 | MAX1111_CTRL_PD1 |
		MAX1111_CTRL_SGL | MAX1111_CTRL_UNI | MAX1111_CTRL_STR;

	err = spi_sync(data->spi, &data->msg);
	if (err < 0) {
		dev_err(dev, "spi_sync failed with %d\n", err);
		mutex_unlock(&data->drvdata_lock);
		return err;
	}

	v1 = data->rx_buf[0];
	v2 = data->rx_buf[1];

	mutex_unlock(&data->drvdata_lock);

	if ((v1 & 0xc0) || (v2 & 0x3f))
		return -EINVAL;

	return (v1 << 2) | (v2 >> 6);
}

#ifdef CONFIG_SHARPSL_PM
static struct max1111_data *the_max1111;

int max1111_read_channel(int channel)
{
	return max1111_read(&the_max1111->spi->dev, channel);
}
EXPORT_SYMBOL(max1111_read_channel);
#endif

/*
 * NOTE: SPI devices do not have a default 'name' attribute, which is
 * likely to be used by hwmon applications to distinguish between
 * different devices, explicitly add a name attribute here.
 */
static ssize_t show_name(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "max1111\n");
}

static ssize_t show_adc(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	int channel = to_sensor_dev_attr(attr)->index;
	int ret;

	ret = max1111_read(dev, channel);
	if (ret < 0)
		return ret;

	/* assume the reference voltage to be 2.048V, with an 8-bit sample,
	 * the LSB weight is 8mV
	 */
	return sprintf(buf, "%d\n", ret * 8);
}

#define MAX1111_ADC_ATTR(_id)		\
	SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id)

static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
static MAX1111_ADC_ATTR(0);
static MAX1111_ADC_ATTR(1);
static MAX1111_ADC_ATTR(2);
static MAX1111_ADC_ATTR(3);

static struct attribute *max1111_attributes[] = {
	&dev_attr_name.attr,
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	NULL,
};

static const struct attribute_group max1111_attr_group = {
	.attrs	= max1111_attributes,
};

static int __devinit setup_transfer(struct max1111_data *data)
{
	struct spi_message *m;
	struct spi_transfer *x;

	m = &data->msg;
	x = &data->xfer[0];

	spi_message_init(m);

	x->tx_buf = &data->tx_buf[0];
	x->len = MAX1111_TX_BUF_SIZE;
	spi_message_add_tail(x, m);

	x++;
	x->rx_buf = &data->rx_buf[0];
	x->len = MAX1111_RX_BUF_SIZE;
	spi_message_add_tail(x, m);

	return 0;
}

static int __devinit max1111_probe(struct spi_device *spi)
{
	struct max1111_data *data;
	int err;

	spi->bits_per_word = 8;
	spi->mode = SPI_MODE_0;
	err = spi_setup(spi);
	if (err < 0)
		return err;

	data = kzalloc(sizeof(struct max1111_data), GFP_KERNEL);
	if (data == NULL) {
		dev_err(&spi->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}

	err = setup_transfer(data);
	if (err)
		goto err_free_data;

	mutex_init(&data->drvdata_lock);

	data->spi = spi;
	spi_set_drvdata(spi, data);

	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
	if (err) {
		dev_err(&spi->dev, "failed to create attribute group\n");
		goto err_free_data;
	}

	data->hwmon_dev = hwmon_device_register(&spi->dev);
	if (IS_ERR(data->hwmon_dev)) {
		dev_err(&spi->dev, "failed to create hwmon device\n");
		err = PTR_ERR(data->hwmon_dev);
		goto err_remove;
	}

#ifdef CONFIG_SHARPSL_PM
	the_max1111 = data;
#endif
	return 0;

err_remove:
	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
err_free_data:
	kfree(data);
	return err;
}

static int __devexit max1111_remove(struct spi_device *spi)
{
	struct max1111_data *data = spi_get_drvdata(spi);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
	mutex_destroy(&data->drvdata_lock);
	kfree(data);
	return 0;
}

static struct spi_driver max1111_driver = {
	.driver		= {
		.name	= "max1111",
		.owner	= THIS_MODULE,
	},
	.probe		= max1111_probe,
	.remove		= __devexit_p(max1111_remove),
};

module_spi_driver(max1111_driver);

MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("MAX1111 ADC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:max1111");
Commit	Line	Data
55b951e7 EM	1	/*
	2	* max1111.c - +2.7V, Low-Power, Multichannel, Serial 8-bit ADCs
	3	*
	4	* Based on arch/arm/mach-pxa/corgi_ssp.c
	5	*
	6	* Copyright (C) 2004-2005 Richard Purdie
	7	*
	8	* Copyright (C) 2008 Marvell International Ltd.
91c8eabe	9	* Eric Miao <eric.miao@marvell.com>
55b951e7 EM	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* publishhed by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/kernel.h>
	18	#include <linux/init.h>
	19	#include <linux/err.h>
	20	#include <linux/hwmon.h>
	21	#include <linux/hwmon-sysfs.h>
	22	#include <linux/spi/spi.h>
5a0e3ad6	23	#include <linux/slab.h>
55b951e7 EM	24
	25	#define MAX1111_TX_BUF_SIZE 1
	26	#define MAX1111_RX_BUF_SIZE 2
	27
	28	/* MAX1111 Commands */
	29	#define MAX1111_CTRL_PD0 (1u << 0)
	30	#define MAX1111_CTRL_PD1 (1u << 1)
	31	#define MAX1111_CTRL_SGL (1u << 2)
	32	#define MAX1111_CTRL_UNI (1u << 3)
	33	#define MAX1111_CTRL_SEL_SH (5) /* NOTE: bit 4 is ignored */
	34	#define MAX1111_CTRL_STR (1u << 7)
	35
	36	struct max1111_data {
	37	struct spi_device *spi;
	38	struct device *hwmon_dev;
	39	struct spi_message msg;
	40	struct spi_transfer xfer[2];
d737c09c JD	41	uint8_t tx_buf[MAX1111_TX_BUF_SIZE];
d737c09c JD	42	uint8_t rx_buf[MAX1111_RX_BUF_SIZE];
d3f684f2 PH	43	struct mutex drvdata_lock;
d3f684f2 PH	44	/* protect msg, xfer and buffers from multiple access */
55b951e7 EM	45	};
	46
	47	static int max1111_read(struct device *dev, int channel)
	48	{
	49	struct max1111_data *data = dev_get_drvdata(dev);
	50	uint8_t v1, v2;
	51	int err;
	52
d3f684f2 PH	53	/* writing to drvdata struct is not thread safe, wait on mutex */
	54	mutex_lock(&data->drvdata_lock);
	55
55b951e7 EM	56	data->tx_buf[0] = (channel << MAX1111_CTRL_SEL_SH) \|
	57	MAX1111_CTRL_PD0 \| MAX1111_CTRL_PD1 \|
	58	MAX1111_CTRL_SGL \| MAX1111_CTRL_UNI \| MAX1111_CTRL_STR;
	59
	60	err = spi_sync(data->spi, &data->msg);
	61	if (err < 0) {
	62	dev_err(dev, "spi_sync failed with %d\n", err);
d3f684f2	63	mutex_unlock(&data->drvdata_lock);
55b951e7 EM	64	return err;
	65	}
	66
	67	v1 = data->rx_buf[0];
	68	v2 = data->rx_buf[1];
	69
d3f684f2 PH	70	mutex_unlock(&data->drvdata_lock);
d3f684f2 PH	71
55b951e7 EM	72	if ((v1 & 0xc0) \|\| (v2 & 0x3f))
	73	return -EINVAL;
	74
	75	return (v1 << 2) \| (v2 >> 6);
	76	}
	77
f16177c2 EM	78	#ifdef CONFIG_SHARPSL_PM
	79	static struct max1111_data *the_max1111;
	80
	81	int max1111_read_channel(int channel)
	82	{
	83	return max1111_read(&the_max1111->spi->dev, channel);
	84	}
	85	EXPORT_SYMBOL(max1111_read_channel);
	86	#endif
	87
55b951e7 EM	88	/*
	89	* NOTE: SPI devices do not have a default 'name' attribute, which is
	90	* likely to be used by hwmon applications to distinguish between
	91	* different devices, explicitly add a name attribute here.
	92	*/
	93	static ssize_t show_name(struct device *dev,
	94	struct device_attribute attr, char buf)
	95	{
	96	return sprintf(buf, "max1111\n");
	97	}
	98
	99	static ssize_t show_adc(struct device *dev,
	100	struct device_attribute attr, char buf)
	101	{
	102	int channel = to_sensor_dev_attr(attr)->index;
	103	int ret;
	104
	105	ret = max1111_read(dev, channel);
	106	if (ret < 0)
	107	return ret;
	108
012f3b91 EM	109	/* assume the reference voltage to be 2.048V, with an 8-bit sample,
	110	* the LSB weight is 8mV
	111	*/
	112	return sprintf(buf, "%d\n", ret * 8);
55b951e7 EM	113	}
	114
	115	#define MAX1111_ADC_ATTR(_id) \
012f3b91	116	SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id)
55b951e7 EM	117
	118	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	119	static MAX1111_ADC_ATTR(0);
	120	static MAX1111_ADC_ATTR(1);
	121	static MAX1111_ADC_ATTR(2);
	122	static MAX1111_ADC_ATTR(3);
	123
	124	static struct attribute *max1111_attributes[] = {
	125	&dev_attr_name.attr,
012f3b91 EM	126	&sensor_dev_attr_in0_input.dev_attr.attr,
	127	&sensor_dev_attr_in1_input.dev_attr.attr,
	128	&sensor_dev_attr_in2_input.dev_attr.attr,
	129	&sensor_dev_attr_in3_input.dev_attr.attr,
55b951e7 EM	130	NULL,
	131	};
	132
	133	static const struct attribute_group max1111_attr_group = {
	134	.attrs = max1111_attributes,
	135	};
	136
d737c09c	137	static int __devinit setup_transfer(struct max1111_data *data)
55b951e7 EM	138	{
	139	struct spi_message *m;
	140	struct spi_transfer *x;
	141
55b951e7 EM	142	m = &data->msg;
	143	x = &data->xfer[0];
	144
	145	spi_message_init(m);
	146
	147	x->tx_buf = &data->tx_buf[0];
d737c09c	148	x->len = MAX1111_TX_BUF_SIZE;
55b951e7 EM	149	spi_message_add_tail(x, m);
	150
	151	x++;
	152	x->rx_buf = &data->rx_buf[0];
d737c09c	153	x->len = MAX1111_RX_BUF_SIZE;
55b951e7 EM	154	spi_message_add_tail(x, m);
	155
	156	return 0;
	157	}
	158
	159	static int __devinit max1111_probe(struct spi_device *spi)
	160	{
	161	struct max1111_data *data;
	162	int err;
	163
	164	spi->bits_per_word = 8;
	165	spi->mode = SPI_MODE_0;
	166	err = spi_setup(spi);
	167	if (err < 0)
	168	return err;
	169
	170	data = kzalloc(sizeof(struct max1111_data), GFP_KERNEL);
	171	if (data == NULL) {
	172	dev_err(&spi->dev, "failed to allocate memory\n");
	173	return -ENOMEM;
	174	}
	175
	176	err = setup_transfer(data);
	177	if (err)
	178	goto err_free_data;
	179
d3f684f2 PH	180	mutex_init(&data->drvdata_lock);
d3f684f2 PH	181
55b951e7 EM	182	data->spi = spi;
	183	spi_set_drvdata(spi, data);
	184
	185	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
	186	if (err) {
	187	dev_err(&spi->dev, "failed to create attribute group\n");
d737c09c	188	goto err_free_data;
55b951e7 EM	189	}
	190
	191	data->hwmon_dev = hwmon_device_register(&spi->dev);
	192	if (IS_ERR(data->hwmon_dev)) {
	193	dev_err(&spi->dev, "failed to create hwmon device\n");
	194	err = PTR_ERR(data->hwmon_dev);
	195	goto err_remove;
	196	}
	197
f16177c2 EM	198	#ifdef CONFIG_SHARPSL_PM
	199	the_max1111 = data;
	200	#endif
55b951e7 EM	201	return 0;
	202
	203	err_remove:
	204	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
55b951e7 EM	205	err_free_data:
	206	kfree(data);
	207	return err;
	208	}
	209
	210	static int __devexit max1111_remove(struct spi_device *spi)
	211	{
	212	struct max1111_data *data = spi_get_drvdata(spi);
	213
	214	hwmon_device_unregister(data->hwmon_dev);
	215	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
d3f684f2	216	mutex_destroy(&data->drvdata_lock);
55b951e7 EM	217	kfree(data);
	218	return 0;
	219	}
	220
	221	static struct spi_driver max1111_driver = {
	222	.driver = {
	223	.name = "max1111",
	224	.owner = THIS_MODULE,
	225	},
	226	.probe = max1111_probe,
	227	.remove = __devexit_p(max1111_remove),
	228	};
	229
91efffe2	230	module_spi_driver(max1111_driver);
55b951e7 EM	231
	232	MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
	233	MODULE_DESCRIPTION("MAX1111 ADC Driver");
	234	MODULE_LICENSE("GPL");
e0626e38	235	MODULE_ALIAS("spi:max1111");