[deliverable/linux.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);
}

/*
 * 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;
	}

	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
69	/*
70	* NOTE: SPI devices do not have a default 'name' attribute, which is
71	* likely to be used by hwmon applications to distinguish between
72	* different devices, explicitly add a name attribute here.
73	*/
74	static ssize_t show_name(struct device *dev,
75	struct device_attribute attr, char buf)
76	{
77	return sprintf(buf, "max1111\n");
78	}
79
80	static ssize_t show_adc(struct device *dev,
81	struct device_attribute attr, char buf)
82	{
83	int channel = to_sensor_dev_attr(attr)->index;
84	int ret;
85
86	ret = max1111_read(dev, channel);
87	if (ret < 0)
88	return ret;
89
90	return sprintf(buf, "%d\n", ret);
91	}
92
93	#define MAX1111_ADC_ATTR(_id) \
94	SENSOR_DEVICE_ATTR(adc##_id##_in, S_IRUGO, show_adc, NULL, _id)
95
96	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
97	static MAX1111_ADC_ATTR(0);
98	static MAX1111_ADC_ATTR(1);
99	static MAX1111_ADC_ATTR(2);
100	static MAX1111_ADC_ATTR(3);
101
102	static struct attribute *max1111_attributes[] = {
103	&dev_attr_name.attr,
104	&sensor_dev_attr_adc0_in.dev_attr.attr,
105	&sensor_dev_attr_adc1_in.dev_attr.attr,
106	&sensor_dev_attr_adc2_in.dev_attr.attr,
107	&sensor_dev_attr_adc3_in.dev_attr.attr,
108	NULL,
109	};
110
111	static const struct attribute_group max1111_attr_group = {
112	.attrs = max1111_attributes,
113	};
114
115	static int setup_transfer(struct max1111_data *data)
116	{
117	struct spi_message *m;
118	struct spi_transfer *x;
119
120	data->tx_buf = kmalloc(MAX1111_TX_BUF_SIZE, GFP_KERNEL);
121	if (!data->tx_buf)
122	return -ENOMEM;
123
124	data->rx_buf = kmalloc(MAX1111_RX_BUF_SIZE, GFP_KERNEL);
125	if (!data->rx_buf) {
126	kfree(data->tx_buf);
127	return -ENOMEM;
128	}
129
130	m = &data->msg;
131	x = &data->xfer[0];
132
133	spi_message_init(m);
134
135	x->tx_buf = &data->tx_buf[0];
136	x->len = 1;
137	spi_message_add_tail(x, m);
138
139	x++;
140	x->rx_buf = &data->rx_buf[0];
141	x->len = 2;
142	spi_message_add_tail(x, m);
143
144	return 0;
145	}
146
147	static int __devinit max1111_probe(struct spi_device *spi)
148	{
149	struct max1111_data *data;
150	int err;
151
152	spi->bits_per_word = 8;
153	spi->mode = SPI_MODE_0;
154	err = spi_setup(spi);
155	if (err < 0)
156	return err;
157
158	data = kzalloc(sizeof(struct max1111_data), GFP_KERNEL);
159	if (data == NULL) {
160	dev_err(&spi->dev, "failed to allocate memory\n");
161	return -ENOMEM;
162	}
163
164	err = setup_transfer(data);
165	if (err)
166	goto err_free_data;
167
168	data->spi = spi;
169	spi_set_drvdata(spi, data);
170
171	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
172	if (err) {
173	dev_err(&spi->dev, "failed to create attribute group\n");
174	goto err_free_all;
175	}
176
177	data->hwmon_dev = hwmon_device_register(&spi->dev);
178	if (IS_ERR(data->hwmon_dev)) {
179	dev_err(&spi->dev, "failed to create hwmon device\n");
180	err = PTR_ERR(data->hwmon_dev);
181	goto err_remove;
182	}
183
184	return 0;
185
186	err_remove:
187	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
188	err_free_all:
189	kfree(data->rx_buf);
190	kfree(data->tx_buf);
191	err_free_data:
192	kfree(data);
193	return err;
194	}
195
196	static int __devexit max1111_remove(struct spi_device *spi)
197	{
198	struct max1111_data *data = spi_get_drvdata(spi);
199
200	hwmon_device_unregister(data->hwmon_dev);
201	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
202	kfree(data->rx_buf);
203	kfree(data->tx_buf);
204	kfree(data);
205	return 0;
206	}
207
208	static struct spi_driver max1111_driver = {
209	.driver = {
210	.name = "max1111",
211	.owner = THIS_MODULE,
212	},
213	.probe = max1111_probe,
214	.remove = __devexit_p(max1111_remove),
215	};
216
217	static int __init max1111_init(void)
218	{
219	return spi_register_driver(&max1111_driver);
220	}
221	module_init(max1111_init);
222
223	static void __exit max1111_exit(void)
224	{
225	spi_unregister_driver(&max1111_driver);
226	}
227	module_exit(max1111_exit);
228
229	MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
230	MODULE_DESCRIPTION("MAX1111 ADC Driver");
231	MODULE_LICENSE("GPL");