[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>

#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;
	uint8_t *rx_buf;
};

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

	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);
		return err;
	}

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

	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;

	return sprintf(buf, "%d\n", ret);
}

#define MAX1111_ADC_ATTR(_id)		\
	SENSOR_DEVICE_ATTR(adc##_id##_in, 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_adc0_in.dev_attr.attr,
	&sensor_dev_attr_adc1_in.dev_attr.attr,
	&sensor_dev_attr_adc2_in.dev_attr.attr,
	&sensor_dev_attr_adc3_in.dev_attr.attr,
	NULL,
};

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

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

	data->tx_buf = kmalloc(MAX1111_TX_BUF_SIZE, GFP_KERNEL);
	if (!data->tx_buf)
		return -ENOMEM;

	data->rx_buf = kmalloc(MAX1111_RX_BUF_SIZE, GFP_KERNEL);
	if (!data->rx_buf) {
		kfree(data->tx_buf);
		return -ENOMEM;
	}

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

	spi_message_init(m);

	x->tx_buf = &data->tx_buf[0];
	x->len = 1;
	spi_message_add_tail(x, m);

	x++;
	x->rx_buf = &data->rx_buf[0];
	x->len = 2;
	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;

	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_all;
	}

	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_all:
	kfree(data->rx_buf);
	kfree(data->tx_buf);
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);
	kfree(data->rx_buf);
	kfree(data->tx_buf);
	kfree(data);
	return 0;
}

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

static int __init max1111_init(void)
{
	return spi_register_driver(&max1111_driver);
}
module_init(max1111_init);

static void __exit max1111_exit(void)
{
	spi_unregister_driver(&max1111_driver);
}
module_exit(max1111_exit);

MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("MAX1111 ADC Driver");
MODULE_LICENSE("GPL");
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.
	9	* Eric Miao <eric.miao@marvell.com>
	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>
	23
	24	#define MAX1111_TX_BUF_SIZE 1
	25	#define MAX1111_RX_BUF_SIZE 2
	26
	27	/* MAX1111 Commands */
	28	#define MAX1111_CTRL_PD0 (1u << 0)
	29	#define MAX1111_CTRL_PD1 (1u << 1)
	30	#define MAX1111_CTRL_SGL (1u << 2)
	31	#define MAX1111_CTRL_UNI (1u << 3)
	32	#define MAX1111_CTRL_SEL_SH (5) /* NOTE: bit 4 is ignored */
	33	#define MAX1111_CTRL_STR (1u << 7)
	34
	35	struct max1111_data {
	36	struct spi_device *spi;
	37	struct device *hwmon_dev;
	38	struct spi_message msg;
	39	struct spi_transfer xfer[2];
	40	uint8_t *tx_buf;
	41	uint8_t *rx_buf;
	42	};
	43
	44	static int max1111_read(struct device *dev, int channel)
	45	{
	46	struct max1111_data *data = dev_get_drvdata(dev);
	47	uint8_t v1, v2;
	48	int err;
	49
	50	data->tx_buf[0] = (channel << MAX1111_CTRL_SEL_SH) \|
	51	MAX1111_CTRL_PD0 \| MAX1111_CTRL_PD1 \|
	52	MAX1111_CTRL_SGL \| MAX1111_CTRL_UNI \| MAX1111_CTRL_STR;
	53
	54	err = spi_sync(data->spi, &data->msg);
	55	if (err < 0) {
	56	dev_err(dev, "spi_sync failed with %d\n", err);
	57	return err;
	58	}
	59
	60	v1 = data->rx_buf[0];
	61	v2 = data->rx_buf[1];
	62
	63	if ((v1 & 0xc0) \|\| (v2 & 0x3f))
	64	return -EINVAL;
65
66	return (v1 << 2) \| (v2 >> 6);
67	}
68
f16177c2 EM	69	#ifdef CONFIG_SHARPSL_PM
	70	static struct max1111_data *the_max1111;
	71
	72	int max1111_read_channel(int channel)
	73	{
	74	return max1111_read(&the_max1111->spi->dev, channel);
	75	}
	76	EXPORT_SYMBOL(max1111_read_channel);
	77	#endif
	78
55b951e7 EM	79	/*
	80	* NOTE: SPI devices do not have a default 'name' attribute, which is
	81	* likely to be used by hwmon applications to distinguish between
	82	* different devices, explicitly add a name attribute here.
	83	*/
	84	static ssize_t show_name(struct device *dev,
	85	struct device_attribute attr, char buf)
	86	{
	87	return sprintf(buf, "max1111\n");
	88	}
	89
	90	static ssize_t show_adc(struct device *dev,
	91	struct device_attribute attr, char buf)
	92	{
	93	int channel = to_sensor_dev_attr(attr)->index;
	94	int ret;
	95
	96	ret = max1111_read(dev, channel);
	97	if (ret < 0)
	98	return ret;
	99
	100	return sprintf(buf, "%d\n", ret);
	101	}
	102
	103	#define MAX1111_ADC_ATTR(_id) \
	104	SENSOR_DEVICE_ATTR(adc##_id##_in, S_IRUGO, show_adc, NULL, _id)
	105
	106	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	107	static MAX1111_ADC_ATTR(0);
	108	static MAX1111_ADC_ATTR(1);
	109	static MAX1111_ADC_ATTR(2);
	110	static MAX1111_ADC_ATTR(3);
	111
	112	static struct attribute *max1111_attributes[] = {
	113	&dev_attr_name.attr,
	114	&sensor_dev_attr_adc0_in.dev_attr.attr,
	115	&sensor_dev_attr_adc1_in.dev_attr.attr,
	116	&sensor_dev_attr_adc2_in.dev_attr.attr,
	117	&sensor_dev_attr_adc3_in.dev_attr.attr,
	118	NULL,
	119	};
	120
	121	static const struct attribute_group max1111_attr_group = {
	122	.attrs = max1111_attributes,
	123	};
	124
	125	static int setup_transfer(struct max1111_data *data)
	126	{
	127	struct spi_message *m;
	128	struct spi_transfer *x;
	129
	130	data->tx_buf = kmalloc(MAX1111_TX_BUF_SIZE, GFP_KERNEL);
	131	if (!data->tx_buf)
	132	return -ENOMEM;
	133
	134	data->rx_buf = kmalloc(MAX1111_RX_BUF_SIZE, GFP_KERNEL);
	135	if (!data->rx_buf) {
	136	kfree(data->tx_buf);
	137	return -ENOMEM;
	138	}
	139
	140	m = &data->msg;
	141	x = &data->xfer[0];
	142
143	spi_message_init(m);
144
145	x->tx_buf = &data->tx_buf[0];
146	x->len = 1;
147	spi_message_add_tail(x, m);
148
149	x++;
150	x->rx_buf = &data->rx_buf[0];
151	x->len = 2;
152	spi_message_add_tail(x, m);
153
154	return 0;
155	}
156
157	static int __devinit max1111_probe(struct spi_device *spi)
158	{
159	struct max1111_data *data;
160	int err;
161
162	spi->bits_per_word = 8;
163	spi->mode = SPI_MODE_0;
164	err = spi_setup(spi);
165	if (err < 0)
166	return err;
167
168	data = kzalloc(sizeof(struct max1111_data), GFP_KERNEL);
169	if (data == NULL) {
170	dev_err(&spi->dev, "failed to allocate memory\n");
171	return -ENOMEM;
172	}
173
174	err = setup_transfer(data);
175	if (err)
176	goto err_free_data;
177
178	data->spi = spi;
179	spi_set_drvdata(spi, data);
180
181	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
182	if (err) {
183	dev_err(&spi->dev, "failed to create attribute group\n");
184	goto err_free_all;
185	}
186
187	data->hwmon_dev = hwmon_device_register(&spi->dev);
188	if (IS_ERR(data->hwmon_dev)) {
189	dev_err(&spi->dev, "failed to create hwmon device\n");
190	err = PTR_ERR(data->hwmon_dev);
191	goto err_remove;
192	}
193
f16177c2 EM	194	#ifdef CONFIG_SHARPSL_PM
	195	the_max1111 = data;
	196	#endif
55b951e7 EM	197	return 0;
	198
	199	err_remove:
	200	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
	201	err_free_all:
	202	kfree(data->rx_buf);
	203	kfree(data->tx_buf);
	204	err_free_data:
	205	kfree(data);
	206	return err;
	207	}
	208
	209	static int __devexit max1111_remove(struct spi_device *spi)
	210	{
	211	struct max1111_data *data = spi_get_drvdata(spi);
	212
	213	hwmon_device_unregister(data->hwmon_dev);
	214	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
	215	kfree(data->rx_buf);
	216	kfree(data->tx_buf);
	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
	230	static int __init max1111_init(void)
	231	{
	232	return spi_register_driver(&max1111_driver);
	233	}
	234	module_init(max1111_init);
	235
	236	static void __exit max1111_exit(void)
	237	{
	238	spi_unregister_driver(&max1111_driver);
	239	}
	240	module_exit(max1111_exit);
	241
	242	MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
	243	MODULE_DESCRIPTION("MAX1111 ADC Driver");
	244	MODULE_LICENSE("GPL");