[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 <[email protected]>
 *
 *  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>

enum chips { max1110, max1111, max1112, max1113 };

#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 MAX1110_CTRL_SEL_SH   (4)
#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 */
	int			sel_sh;
	int			lsb;
};

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 << data->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, "%s\n", to_spi_device(dev)->modalias);
}

static ssize_t show_adc(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	struct max1111_data *data = dev_get_drvdata(dev);
	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 or 4.096V, with an 8-bit
	 * sample. The LSB weight is 8mV or 16mV depending on the chip type.
	 */
	return sprintf(buf, "%d\n", ret * data->lsb);
}

#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 MAX1111_ADC_ATTR(4);
static MAX1111_ADC_ATTR(5);
static MAX1111_ADC_ATTR(6);
static MAX1111_ADC_ATTR(7);

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 struct attribute *max1110_attributes[] = {
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	NULL,
};

static const struct attribute_group max1110_attr_group = {
	.attrs	= max1110_attributes,
};

static int 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 max1111_probe(struct spi_device *spi)
{
	enum chips chip = spi_get_device_id(spi)->driver_data;
	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 = devm_kzalloc(&spi->dev, sizeof(struct max1111_data), GFP_KERNEL);
	if (data == NULL) {
		dev_err(&spi->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}

	switch (chip) {
	case max1110:
		data->lsb = 8;
		data->sel_sh = MAX1110_CTRL_SEL_SH;
		break;
	case max1111:
		data->lsb = 8;
		data->sel_sh = MAX1111_CTRL_SEL_SH;
		break;
	case max1112:
		data->lsb = 16;
		data->sel_sh = MAX1110_CTRL_SEL_SH;
		break;
	case max1113:
		data->lsb = 16;
		data->sel_sh = MAX1111_CTRL_SEL_SH;
		break;
	}
	err = setup_transfer(data);
	if (err)
		return err;

	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");
		return err;
	}
	if (chip == max1110 || chip == max1112) {
		err = sysfs_create_group(&spi->dev.kobj, &max1110_attr_group);
		if (err) {
			dev_err(&spi->dev,
				"failed to create extended attribute group\n");
			goto err_remove;
		}
	}

	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, &max1110_attr_group);
	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
	return err;
}

static int 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, &max1110_attr_group);
	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
	mutex_destroy(&data->drvdata_lock);
	return 0;
}

static const struct spi_device_id max1111_ids[] = {
	{ "max1110", max1110 },
	{ "max1111", max1111 },
	{ "max1112", max1112 },
	{ "max1113", max1113 },
	{ },
};
MODULE_DEVICE_TABLE(spi, max1111_ids);

static struct spi_driver max1111_driver = {
	.driver		= {
		.name	= "max1111",
		.owner	= THIS_MODULE,
	},
	.id_table	= max1111_ids,
	.probe		= max1111_probe,
	.remove		= max1111_remove,
};

module_spi_driver(max1111_driver);

MODULE_AUTHOR("Eric Miao <[email protected]>");
MODULE_DESCRIPTION("MAX1110/MAX1111/MAX1112/MAX1113 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.
91c8eabe	9	* Eric Miao <[email protected]>
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	24
9224c38a GR	25	enum chips { max1110, max1111, max1112, max1113 };
9224c38a GR	26
55b951e7 EM	27	#define MAX1111_TX_BUF_SIZE 1
	28	#define MAX1111_RX_BUF_SIZE 2
	29
	30	/* MAX1111 Commands */
	31	#define MAX1111_CTRL_PD0 (1u << 0)
	32	#define MAX1111_CTRL_PD1 (1u << 1)
	33	#define MAX1111_CTRL_SGL (1u << 2)
	34	#define MAX1111_CTRL_UNI (1u << 3)
9224c38a	35	#define MAX1110_CTRL_SEL_SH (4)
55b951e7 EM	36	#define MAX1111_CTRL_SEL_SH (5) /* NOTE: bit 4 is ignored */
	37	#define MAX1111_CTRL_STR (1u << 7)
	38
	39	struct max1111_data {
	40	struct spi_device *spi;
	41	struct device *hwmon_dev;
	42	struct spi_message msg;
	43	struct spi_transfer xfer[2];
d737c09c JD	44	uint8_t tx_buf[MAX1111_TX_BUF_SIZE];
d737c09c JD	45	uint8_t rx_buf[MAX1111_RX_BUF_SIZE];
d3f684f2 PH	46	struct mutex drvdata_lock;
d3f684f2 PH	47	/* protect msg, xfer and buffers from multiple access */
9224c38a GR	48	int sel_sh;
9224c38a GR	49	int lsb;
55b951e7 EM	50	};
	51
	52	static int max1111_read(struct device *dev, int channel)
	53	{
	54	struct max1111_data *data = dev_get_drvdata(dev);
	55	uint8_t v1, v2;
	56	int err;
	57
d3f684f2 PH	58	/* writing to drvdata struct is not thread safe, wait on mutex */
	59	mutex_lock(&data->drvdata_lock);
	60
9224c38a	61	data->tx_buf[0] = (channel << data->sel_sh) \|
55b951e7 EM	62	MAX1111_CTRL_PD0 \| MAX1111_CTRL_PD1 \|
	63	MAX1111_CTRL_SGL \| MAX1111_CTRL_UNI \| MAX1111_CTRL_STR;
	64
	65	err = spi_sync(data->spi, &data->msg);
	66	if (err < 0) {
	67	dev_err(dev, "spi_sync failed with %d\n", err);
d3f684f2	68	mutex_unlock(&data->drvdata_lock);
55b951e7 EM	69	return err;
	70	}
	71
	72	v1 = data->rx_buf[0];
	73	v2 = data->rx_buf[1];
	74
d3f684f2 PH	75	mutex_unlock(&data->drvdata_lock);
d3f684f2 PH	76
55b951e7 EM	77	if ((v1 & 0xc0) \|\| (v2 & 0x3f))
	78	return -EINVAL;
	79
	80	return (v1 << 2) \| (v2 >> 6);
	81	}
	82
f16177c2 EM	83	#ifdef CONFIG_SHARPSL_PM
	84	static struct max1111_data *the_max1111;
	85
	86	int max1111_read_channel(int channel)
	87	{
	88	return max1111_read(&the_max1111->spi->dev, channel);
	89	}
	90	EXPORT_SYMBOL(max1111_read_channel);
	91	#endif
	92
55b951e7 EM	93	/*
	94	* NOTE: SPI devices do not have a default 'name' attribute, which is
	95	* likely to be used by hwmon applications to distinguish between
	96	* different devices, explicitly add a name attribute here.
	97	*/
	98	static ssize_t show_name(struct device *dev,
	99	struct device_attribute attr, char buf)
	100	{
9224c38a	101	return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
55b951e7 EM	102	}
	103
	104	static ssize_t show_adc(struct device *dev,
	105	struct device_attribute attr, char buf)
	106	{
9224c38a	107	struct max1111_data *data = dev_get_drvdata(dev);
55b951e7 EM	108	int channel = to_sensor_dev_attr(attr)->index;
	109	int ret;
	110
	111	ret = max1111_read(dev, channel);
	112	if (ret < 0)
	113	return ret;
	114
51683ee8	115	/*
9224c38a GR	116	* Assume the reference voltage to be 2.048V or 4.096V, with an 8-bit
9224c38a GR	117	* sample. The LSB weight is 8mV or 16mV depending on the chip type.
012f3b91	118	*/
9224c38a	119	return sprintf(buf, "%d\n", ret * data->lsb);
55b951e7 EM	120	}
	121
	122	#define MAX1111_ADC_ATTR(_id) \
012f3b91	123	SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id)
55b951e7 EM	124
	125	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	126	static MAX1111_ADC_ATTR(0);
	127	static MAX1111_ADC_ATTR(1);
	128	static MAX1111_ADC_ATTR(2);
	129	static MAX1111_ADC_ATTR(3);
9224c38a GR	130	static MAX1111_ADC_ATTR(4);
	131	static MAX1111_ADC_ATTR(5);
	132	static MAX1111_ADC_ATTR(6);
	133	static MAX1111_ADC_ATTR(7);
55b951e7 EM	134
	135	static struct attribute *max1111_attributes[] = {
	136	&dev_attr_name.attr,
012f3b91 EM	137	&sensor_dev_attr_in0_input.dev_attr.attr,
	138	&sensor_dev_attr_in1_input.dev_attr.attr,
	139	&sensor_dev_attr_in2_input.dev_attr.attr,
	140	&sensor_dev_attr_in3_input.dev_attr.attr,
55b951e7 EM	141	NULL,
	142	};
	143
	144	static const struct attribute_group max1111_attr_group = {
	145	.attrs = max1111_attributes,
	146	};
	147
9224c38a GR	148	static struct attribute *max1110_attributes[] = {
	149	&sensor_dev_attr_in4_input.dev_attr.attr,
	150	&sensor_dev_attr_in5_input.dev_attr.attr,
	151	&sensor_dev_attr_in6_input.dev_attr.attr,
	152	&sensor_dev_attr_in7_input.dev_attr.attr,
	153	NULL,
	154	};
	155
	156	static const struct attribute_group max1110_attr_group = {
	157	.attrs = max1110_attributes,
	158	};
	159
6c931ae1	160	static int setup_transfer(struct max1111_data *data)
55b951e7 EM	161	{
	162	struct spi_message *m;
	163	struct spi_transfer *x;
	164
55b951e7 EM	165	m = &data->msg;
	166	x = &data->xfer[0];
	167
	168	spi_message_init(m);
	169
	170	x->tx_buf = &data->tx_buf[0];
d737c09c	171	x->len = MAX1111_TX_BUF_SIZE;
55b951e7 EM	172	spi_message_add_tail(x, m);
	173
	174	x++;
	175	x->rx_buf = &data->rx_buf[0];
d737c09c	176	x->len = MAX1111_RX_BUF_SIZE;
55b951e7 EM	177	spi_message_add_tail(x, m);
	178
	179	return 0;
	180	}
	181
6c931ae1	182	static int max1111_probe(struct spi_device *spi)
55b951e7	183	{
9224c38a	184	enum chips chip = spi_get_device_id(spi)->driver_data;
55b951e7 EM	185	struct max1111_data *data;
	186	int err;
	187
	188	spi->bits_per_word = 8;
	189	spi->mode = SPI_MODE_0;
	190	err = spi_setup(spi);
	191	if (err < 0)
	192	return err;
	193
661f020f	194	data = devm_kzalloc(&spi->dev, sizeof(struct max1111_data), GFP_KERNEL);
55b951e7 EM	195	if (data == NULL) {
	196	dev_err(&spi->dev, "failed to allocate memory\n");
	197	return -ENOMEM;
	198	}
	199
9224c38a GR	200	switch (chip) {
	201	case max1110:
	202	data->lsb = 8;
	203	data->sel_sh = MAX1110_CTRL_SEL_SH;
	204	break;
	205	case max1111:
	206	data->lsb = 8;
	207	data->sel_sh = MAX1111_CTRL_SEL_SH;
	208	break;
	209	case max1112:
	210	data->lsb = 16;
	211	data->sel_sh = MAX1110_CTRL_SEL_SH;
	212	break;
	213	case max1113:
	214	data->lsb = 16;
	215	data->sel_sh = MAX1111_CTRL_SEL_SH;
	216	break;
	217	}
55b951e7 EM	218	err = setup_transfer(data);
55b951e7 EM	219	if (err)
661f020f	220	return err;
55b951e7	221
d3f684f2 PH	222	mutex_init(&data->drvdata_lock);
d3f684f2 PH	223
55b951e7 EM	224	data->spi = spi;
	225	spi_set_drvdata(spi, data);
	226
	227	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
	228	if (err) {
	229	dev_err(&spi->dev, "failed to create attribute group\n");
661f020f	230	return err;
55b951e7	231	}
9224c38a GR	232	if (chip == max1110 \|\| chip == max1112) {
	233	err = sysfs_create_group(&spi->dev.kobj, &max1110_attr_group);
	234	if (err) {
	235	dev_err(&spi->dev,
	236	"failed to create extended attribute group\n");
	237	goto err_remove;
	238	}
	239	}
55b951e7 EM	240
	241	data->hwmon_dev = hwmon_device_register(&spi->dev);
	242	if (IS_ERR(data->hwmon_dev)) {
	243	dev_err(&spi->dev, "failed to create hwmon device\n");
	244	err = PTR_ERR(data->hwmon_dev);
	245	goto err_remove;
	246	}
	247
f16177c2 EM	248	#ifdef CONFIG_SHARPSL_PM
	249	the_max1111 = data;
	250	#endif
55b951e7 EM	251	return 0;
	252
	253	err_remove:
9224c38a	254	sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group);
55b951e7	255	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
55b951e7 EM	256	return err;
	257	}
	258
281dfd0b	259	static int max1111_remove(struct spi_device *spi)
55b951e7 EM	260	{
	261	struct max1111_data *data = spi_get_drvdata(spi);
	262
	263	hwmon_device_unregister(data->hwmon_dev);
9224c38a	264	sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group);
55b951e7	265	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
d3f684f2	266	mutex_destroy(&data->drvdata_lock);
55b951e7 EM	267	return 0;
	268	}
	269
9224c38a GR	270	static const struct spi_device_id max1111_ids[] = {
	271	{ "max1110", max1110 },
	272	{ "max1111", max1111 },
	273	{ "max1112", max1112 },
	274	{ "max1113", max1113 },
	275	{ },
	276	};
	277	MODULE_DEVICE_TABLE(spi, max1111_ids);
	278
55b951e7 EM	279	static struct spi_driver max1111_driver = {
	280	.driver = {
	281	.name = "max1111",
	282	.owner = THIS_MODULE,
	283	},
9224c38a	284	.id_table = max1111_ids,
55b951e7	285	.probe = max1111_probe,
9e5e9b7a	286	.remove = max1111_remove,
55b951e7 EM	287	};
55b951e7 EM	288
91efffe2	289	module_spi_driver(max1111_driver);
55b951e7 EM	290
55b951e7 EM	291	MODULE_AUTHOR("Eric Miao <[email protected]>");
9224c38a	292	MODULE_DESCRIPTION("MAX1110/MAX1111/MAX1112/MAX1113 ADC Driver");
55b951e7	293	MODULE_LICENSE("GPL");