[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / hwmon / adcxx.c

/*
 * adcxx.c
 *
 * The adcxx4s is an AD converter family from National Semiconductor (NS).
 *
 * Copyright (c) 2008 Marc Pignat <marc.pignat@hevs.ch>
 *
 * The adcxx4s communicates with a host processor via an SPI/Microwire Bus
 * interface. This driver supports the whole family of devices with name
 * ADC<bb><c>S<sss>, where
 * * bb is the resolution in number of bits (8, 10, 12)
 * * c is the number of channels (1, 2, 4, 8)
 * * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
 *   and 101 for 1 MSPS)
 *
 * Complete datasheets are available at National's website here:
 * http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf
 *
 * Handling of 8, 10 and 12 bits converters are the same, the
 * unavailable bits are 0 :)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

#define DRVNAME		"adcxx"

struct adcxx {
	struct device *hwmon_dev;
	struct mutex lock;
	u32 channels;
	u32 reference; /* in millivolts */
};

/* sysfs hook function */
static ssize_t adcxx_read(struct device *dev,
		struct device_attribute *devattr, char *buf)
{
	struct spi_device *spi = to_spi_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	u8 tx_buf[2];
	u8 rx_buf[2];
	int status;
	u32 value;

	if (mutex_lock_interruptible(&adc->lock))
		return -ERESTARTSYS;

	if (adc->channels == 1) {
		status = spi_read(spi, rx_buf, sizeof(rx_buf));
	} else {
		tx_buf[0] = attr->index << 3; /* other bits are don't care */
		status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf),
						rx_buf, sizeof(rx_buf));
	}
	if (status < 0) {
		dev_warn(dev, "SPI synch. transfer failed with status %d\n",
				status);
		goto out;
	}

	value = (rx_buf[0] << 8) + rx_buf[1];
	dev_dbg(dev, "raw value = 0x%x\n", value);

	value = value * adc->reference >> 12;
	status = sprintf(buf, "%d\n", value);
out:
	mutex_unlock(&adc->lock);
	return status;
}

static ssize_t adcxx_show_min(struct device *dev,
		struct device_attribute *devattr, char *buf)
{
	/* The minimum reference is 0 for this chip family */
	return sprintf(buf, "0\n");
}

static ssize_t adcxx_show_max(struct device *dev,
		struct device_attribute *devattr, char *buf)
{
	struct spi_device *spi = to_spi_device(dev);
	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	u32 reference;

	if (mutex_lock_interruptible(&adc->lock))
		return -ERESTARTSYS;

	reference = adc->reference;

	mutex_unlock(&adc->lock);

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

static ssize_t adcxx_set_max(struct device *dev,
	struct device_attribute *devattr, const char *buf, size_t count)
{
	struct spi_device *spi = to_spi_device(dev);
	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	unsigned long value;

	if (strict_strtoul(buf, 10, &value))
		return -EINVAL;

	if (mutex_lock_interruptible(&adc->lock))
		return -ERESTARTSYS;

	adc->reference = value;

	mutex_unlock(&adc->lock);

	return count;
}

static ssize_t adcxx_show_name(struct device *dev, struct device_attribute
			      *devattr, char *buf)
{
	struct spi_device *spi = to_spi_device(dev);
	struct adcxx *adc = dev_get_drvdata(&spi->dev);

	return sprintf(buf, "adcxx%ds\n", adc->channels);
}

static struct sensor_device_attribute ad_input[] = {
	SENSOR_ATTR(name, S_IRUGO, adcxx_show_name, NULL, 0),
	SENSOR_ATTR(in_min, S_IRUGO, adcxx_show_min, NULL, 0),
	SENSOR_ATTR(in_max, S_IWUSR | S_IRUGO, adcxx_show_max,
					adcxx_set_max, 0),
	SENSOR_ATTR(in0_input, S_IRUGO, adcxx_read, NULL, 0),
	SENSOR_ATTR(in1_input, S_IRUGO, adcxx_read, NULL, 1),
	SENSOR_ATTR(in2_input, S_IRUGO, adcxx_read, NULL, 2),
	SENSOR_ATTR(in3_input, S_IRUGO, adcxx_read, NULL, 3),
	SENSOR_ATTR(in4_input, S_IRUGO, adcxx_read, NULL, 4),
	SENSOR_ATTR(in5_input, S_IRUGO, adcxx_read, NULL, 5),
	SENSOR_ATTR(in6_input, S_IRUGO, adcxx_read, NULL, 6),
	SENSOR_ATTR(in7_input, S_IRUGO, adcxx_read, NULL, 7),
};

/*----------------------------------------------------------------------*/

static int __devinit adcxx_probe(struct spi_device *spi)
{
	int channels = spi_get_device_id(spi)->driver_data;
	struct adcxx *adc;
	int status;
	int i;

	adc = kzalloc(sizeof *adc, GFP_KERNEL);
	if (!adc)
		return -ENOMEM;

	/* set a default value for the reference */
	adc->reference = 3300;
	adc->channels = channels;
	mutex_init(&adc->lock);

	mutex_lock(&adc->lock);

	dev_set_drvdata(&spi->dev, adc);

	for (i = 0; i < 3 + adc->channels; i++) {
		status = device_create_file(&spi->dev, &ad_input[i].dev_attr);
		if (status) {
			dev_err(&spi->dev, "device_create_file failed.\n");
			goto out_err;
		}
	}

	adc->hwmon_dev = hwmon_device_register(&spi->dev);
	if (IS_ERR(adc->hwmon_dev)) {
		dev_err(&spi->dev, "hwmon_device_register failed.\n");
		status = PTR_ERR(adc->hwmon_dev);
		goto out_err;
	}

	mutex_unlock(&adc->lock);
	return 0;

out_err:
	for (i--; i >= 0; i--)
		device_remove_file(&spi->dev, &ad_input[i].dev_attr);

	dev_set_drvdata(&spi->dev, NULL);
	mutex_unlock(&adc->lock);
	kfree(adc);
	return status;
}

static int __devexit adcxx_remove(struct spi_device *spi)
{
	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	int i;

	mutex_lock(&adc->lock);
	hwmon_device_unregister(adc->hwmon_dev);
	for (i = 0; i < 3 + adc->channels; i++)
		device_remove_file(&spi->dev, &ad_input[i].dev_attr);

	dev_set_drvdata(&spi->dev, NULL);
	mutex_unlock(&adc->lock);
	kfree(adc);

	return 0;
}

static const struct spi_device_id adcxx_ids[] = {
	{ "adcxx1s", 1 },
	{ "adcxx2s", 2 },
	{ "adcxx4s", 4 },
	{ "adcxx8s", 8 },
	{ },
};
MODULE_DEVICE_TABLE(spi, adcxx_ids);

static struct spi_driver adcxx_driver = {
	.driver = {
		.name	= "adcxx",
		.owner	= THIS_MODULE,
	},
	.id_table = adcxx_ids,
	.probe	= adcxx_probe,
	.remove	= __devexit_p(adcxx_remove),
};

static int __init init_adcxx(void)
{
	return spi_register_driver(&adcxx_driver);
}

static void __exit exit_adcxx(void)
{
	spi_unregister_driver(&adcxx_driver);
}

module_init(init_adcxx);
module_exit(exit_adcxx);

MODULE_AUTHOR("Marc Pignat");
MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
d42139a3 MP	1	/*
	2	* adcxx.c
	3	*
	4	* The adcxx4s is an AD converter family from National Semiconductor (NS).
	5	*
	6	* Copyright (c) 2008 Marc Pignat <marc.pignat@hevs.ch>
	7	*
	8	* The adcxx4s communicates with a host processor via an SPI/Microwire Bus
	9	* interface. This driver supports the whole family of devices with name
	10	* ADC<bb><c>S<sss>, where
	11	* * bb is the resolution in number of bits (8, 10, 12)
	12	* * c is the number of channels (1, 2, 4, 8)
	13	* * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
	14	* and 101 for 1 MSPS)
	15	*
	16	* Complete datasheets are available at National's website here:
	17	* http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf
	18	*
	19	* Handling of 8, 10 and 12 bits converters are the same, the
	20	* unavailable bits are 0 :)
	21	*
	22	* This program is free software; you can redistribute it and/or modify
	23	* it under the terms of the GNU General Public License as published by
	24	* the Free Software Foundation; either version 2 of the License, or
	25	* (at your option) any later version.
	26	*
	27	* This program is distributed in the hope that it will be useful,
	28	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	29	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	30	* GNU General Public License for more details.
	31	*
	32	* You should have received a copy of the GNU General Public License
	33	* along with this program; if not, write to the Free Software
	34	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	35	*/
	36
	37	#include <linux/init.h>
	38	#include <linux/module.h>
	39	#include <linux/kernel.h>
5a0e3ad6	40	#include <linux/slab.h>
d42139a3 MP	41	#include <linux/device.h>
	42	#include <linux/err.h>
	43	#include <linux/sysfs.h>
	44	#include <linux/hwmon.h>
	45	#include <linux/hwmon-sysfs.h>
	46	#include <linux/mutex.h>
d2a5c10f	47	#include <linux/mod_devicetable.h>
d42139a3 MP	48	#include <linux/spi/spi.h>
	49
	50	#define DRVNAME "adcxx"
	51
	52	struct adcxx {
	53	struct device *hwmon_dev;
	54	struct mutex lock;
	55	u32 channels;
	56	u32 reference; /* in millivolts */
	57	};
	58
	59	/* sysfs hook function */
	60	static ssize_t adcxx_read(struct device *dev,
	61	struct device_attribute devattr, char buf)
	62	{
	63	struct spi_device *spi = to_spi_device(dev);
	64	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	65	struct adcxx *adc = dev_get_drvdata(&spi->dev);
5748150e	66	u8 tx_buf[2];
d42139a3 MP	67	u8 rx_buf[2];
d42139a3 MP	68	int status;
5748150e	69	u32 value;
d42139a3 MP	70
	71	if (mutex_lock_interruptible(&adc->lock))
	72	return -ERESTARTSYS;
	73
5748150e JMG	74	if (adc->channels == 1) {
	75	status = spi_read(spi, rx_buf, sizeof(rx_buf));
	76	} else {
	77	tx_buf[0] = attr->index << 3; /* other bits are don't care */
	78	status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf),
	79	rx_buf, sizeof(rx_buf));
	80	}
d42139a3	81	if (status < 0) {
5748150e	82	dev_warn(dev, "SPI synch. transfer failed with status %d\n",
d42139a3 MP	83	status);
	84	goto out;
	85	}
	86
	87	value = (rx_buf[0] << 8) + rx_buf[1];
	88	dev_dbg(dev, "raw value = 0x%x\n", value);
	89
	90	value = value * adc->reference >> 12;
	91	status = sprintf(buf, "%d\n", value);
	92	out:
	93	mutex_unlock(&adc->lock);
	94	return status;
	95	}
	96
	97	static ssize_t adcxx_show_min(struct device *dev,
	98	struct device_attribute devattr, char buf)
	99	{
	100	/* The minimum reference is 0 for this chip family */
	101	return sprintf(buf, "0\n");
	102	}
	103
	104	static ssize_t adcxx_show_max(struct device *dev,
	105	struct device_attribute devattr, char buf)
	106	{
	107	struct spi_device *spi = to_spi_device(dev);
	108	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	109	u32 reference;
	110
	111	if (mutex_lock_interruptible(&adc->lock))
	112	return -ERESTARTSYS;
	113
	114	reference = adc->reference;
	115
	116	mutex_unlock(&adc->lock);
	117
	118	return sprintf(buf, "%d\n", reference);
	119	}
	120
	121	static ssize_t adcxx_set_max(struct device *dev,
	122	struct device_attribute devattr, const char buf, size_t count)
	123	{
	124	struct spi_device *spi = to_spi_device(dev);
	125	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	126	unsigned long value;
	127
	128	if (strict_strtoul(buf, 10, &value))
	129	return -EINVAL;
	130
	131	if (mutex_lock_interruptible(&adc->lock))
	132	return -ERESTARTSYS;
	133
	134	adc->reference = value;
	135
	136	mutex_unlock(&adc->lock);
	137
	138	return count;
	139	}
	140
	141	static ssize_t adcxx_show_name(struct device *dev, struct device_attribute
	142	devattr, char buf)
	143	{
	144	struct spi_device *spi = to_spi_device(dev);
	145	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	146
147	return sprintf(buf, "adcxx%ds\n", adc->channels);
148	}
149
150	static struct sensor_device_attribute ad_input[] = {
151	SENSOR_ATTR(name, S_IRUGO, adcxx_show_name, NULL, 0),
152	SENSOR_ATTR(in_min, S_IRUGO, adcxx_show_min, NULL, 0),
153	SENSOR_ATTR(in_max, S_IWUSR \| S_IRUGO, adcxx_show_max,
154	adcxx_set_max, 0),
155	SENSOR_ATTR(in0_input, S_IRUGO, adcxx_read, NULL, 0),
156	SENSOR_ATTR(in1_input, S_IRUGO, adcxx_read, NULL, 1),
157	SENSOR_ATTR(in2_input, S_IRUGO, adcxx_read, NULL, 2),
158	SENSOR_ATTR(in3_input, S_IRUGO, adcxx_read, NULL, 3),
159	SENSOR_ATTR(in4_input, S_IRUGO, adcxx_read, NULL, 4),
160	SENSOR_ATTR(in5_input, S_IRUGO, adcxx_read, NULL, 5),
161	SENSOR_ATTR(in6_input, S_IRUGO, adcxx_read, NULL, 6),
162	SENSOR_ATTR(in7_input, S_IRUGO, adcxx_read, NULL, 7),
163	};
164
165	/----------------------------------------------------------------------/
166
d2a5c10f	167	static int __devinit adcxx_probe(struct spi_device *spi)
d42139a3	168	{
d2a5c10f	169	int channels = spi_get_device_id(spi)->driver_data;
d42139a3 MP	170	struct adcxx *adc;
	171	int status;
	172	int i;
	173
	174	adc = kzalloc(sizeof *adc, GFP_KERNEL);
	175	if (!adc)
	176	return -ENOMEM;
	177
	178	/* set a default value for the reference */
	179	adc->reference = 3300;
	180	adc->channels = channels;
	181	mutex_init(&adc->lock);
	182
	183	mutex_lock(&adc->lock);
	184
	185	dev_set_drvdata(&spi->dev, adc);
	186
	187	for (i = 0; i < 3 + adc->channels; i++) {
	188	status = device_create_file(&spi->dev, &ad_input[i].dev_attr);
	189	if (status) {
	190	dev_err(&spi->dev, "device_create_file failed.\n");
	191	goto out_err;
	192	}
	193	}
	194
	195	adc->hwmon_dev = hwmon_device_register(&spi->dev);
	196	if (IS_ERR(adc->hwmon_dev)) {
	197	dev_err(&spi->dev, "hwmon_device_register failed.\n");
	198	status = PTR_ERR(adc->hwmon_dev);
	199	goto out_err;
	200	}
	201
	202	mutex_unlock(&adc->lock);
	203	return 0;
	204
	205	out_err:
	206	for (i--; i >= 0; i--)
	207	device_remove_file(&spi->dev, &ad_input[i].dev_attr);
	208
	209	dev_set_drvdata(&spi->dev, NULL);
	210	mutex_unlock(&adc->lock);
	211	kfree(adc);
	212	return status;
	213	}
	214
d42139a3 MP	215	static int __devexit adcxx_remove(struct spi_device *spi)
	216	{
	217	struct adcxx *adc = dev_get_drvdata(&spi->dev);
	218	int i;
	219
	220	mutex_lock(&adc->lock);
	221	hwmon_device_unregister(adc->hwmon_dev);
	222	for (i = 0; i < 3 + adc->channels; i++)
	223	device_remove_file(&spi->dev, &ad_input[i].dev_attr);
	224
	225	dev_set_drvdata(&spi->dev, NULL);
	226	mutex_unlock(&adc->lock);
	227	kfree(adc);
	228
	229	return 0;
	230	}
	231
d2a5c10f AV	232	static const struct spi_device_id adcxx_ids[] = {
	233	{ "adcxx1s", 1 },
	234	{ "adcxx2s", 2 },
	235	{ "adcxx4s", 4 },
	236	{ "adcxx8s", 8 },
	237	{ },
d42139a3	238	};
d2a5c10f	239	MODULE_DEVICE_TABLE(spi, adcxx_ids);
d42139a3	240
d2a5c10f	241	static struct spi_driver adcxx_driver = {
d42139a3	242	.driver = {
d2a5c10f	243	.name = "adcxx",
d42139a3 MP	244	.owner = THIS_MODULE,
d42139a3 MP	245	},
d2a5c10f AV	246	.id_table = adcxx_ids,
d2a5c10f AV	247	.probe = adcxx_probe,
d42139a3 MP	248	.remove = __devexit_p(adcxx_remove),
	249	};
	250
	251	static int __init init_adcxx(void)
	252	{
d2a5c10f	253	return spi_register_driver(&adcxx_driver);
d42139a3 MP	254	}
	255
	256	static void __exit exit_adcxx(void)
	257	{
d2a5c10f	258	spi_unregister_driver(&adcxx_driver);
d42139a3 MP	259	}
	260
	261	module_init(init_adcxx);
	262	module_exit(exit_adcxx);
	263
	264	MODULE_AUTHOR("Marc Pignat");
	265	MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver");
	266	MODULE_LICENSE("GPL");