[linux-2.6-block.git] / drivers / hwmon / lm70.c

/*
 * lm70.c
 *
 * The LM70 is a temperature sensor chip from National Semiconductor (NS).
 * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
 *
 * The LM70 communicates with a host processor via an SPI/Microwire Bus
 * interface. The complete datasheet is available at National's website
 * here:
 * http://www.national.com/pf/LM/LM70.html
 *
 * 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/device.h>
#include <linux/err.h>
#include <linux/sysfs.h>
#include <linux/hwmon.h>
#include <linux/mutex.h>
#include <linux/spi/spi.h>


#define DRVNAME		"lm70"

#define LM70_CHIP_LM70		0	/* original NS LM70 */
#define LM70_CHIP_TMP121	1	/* TI TMP121/TMP123 */

struct lm70 {
	struct device *hwmon_dev;
	struct mutex lock;
	unsigned int chip;
};

/* sysfs hook function */
static ssize_t lm70_sense_temp(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct spi_device *spi = to_spi_device(dev);
	int status, val = 0;
	u8 rxbuf[2];
	s16 raw=0;
	struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);

	if (mutex_lock_interruptible(&p_lm70->lock))
		return -ERESTARTSYS;

	/*
	 * spi_read() requires a DMA-safe buffer; so we use
	 * spi_write_then_read(), transmitting 0 bytes.
	 */
	status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
	if (status < 0) {
		printk(KERN_WARNING
		"spi_write_then_read failed with status %d\n", status);
		goto out;
	}
	raw = (rxbuf[0] << 8) + rxbuf[1];
	dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
		rxbuf[0], rxbuf[1], raw);

	/*
	 * LM70:
	 * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
	 * complement value. Only the MSB 11 bits (1 sign + 10 temperature
	 * bits) are meaningful; the LSB 5 bits are to be discarded.
	 * See the datasheet.
	 *
	 * Further, each bit represents 0.25 degrees Celsius; so, multiply
	 * by 0.25. Also multiply by 1000 to represent in millidegrees
	 * Celsius.
	 * So it's equivalent to multiplying by 0.25 * 1000 = 250.
	 *
	 * TMP121/TMP123:
	 * 13 bits of 2's complement data, discard LSB 3 bits,
	 * resolution 0.0625 degrees celsius.
	 */
	switch (p_lm70->chip) {
	case LM70_CHIP_LM70:
		val = ((int)raw / 32) * 250;
		break;

	case LM70_CHIP_TMP121:
		val = ((int)raw / 8) * 625 / 10;
		break;
	}

	status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
out:
	mutex_unlock(&p_lm70->lock);
	return status;
}

static DEVICE_ATTR(temp1_input, S_IRUGO, lm70_sense_temp, NULL);

static ssize_t lm70_show_name(struct device *dev, struct device_attribute
			      *devattr, char *buf)
{
	struct lm70 *p_lm70 = dev_get_drvdata(dev);
	int ret;

	switch (p_lm70->chip) {
	case LM70_CHIP_LM70:
		ret = sprintf(buf, "lm70\n");
		break;
	case LM70_CHIP_TMP121:
		ret = sprintf(buf, "tmp121\n");
		break;
	default:
		ret = -EINVAL;
	}
	return ret;
}

static DEVICE_ATTR(name, S_IRUGO, lm70_show_name, NULL);

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

static int __devinit common_probe(struct spi_device *spi, int chip)
{
	struct lm70 *p_lm70;
	int status;

	/* NOTE:  we assume 8-bit words, and convert to 16 bits manually */

	p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL);
	if (!p_lm70)
		return -ENOMEM;

	mutex_init(&p_lm70->lock);
	p_lm70->chip = chip;

	/* sysfs hook */
	p_lm70->hwmon_dev = hwmon_device_register(&spi->dev);
	if (IS_ERR(p_lm70->hwmon_dev)) {
		dev_dbg(&spi->dev, "hwmon_device_register failed.\n");
		status = PTR_ERR(p_lm70->hwmon_dev);
		goto out_dev_reg_failed;
	}
	dev_set_drvdata(&spi->dev, p_lm70);

	if ((status = device_create_file(&spi->dev, &dev_attr_temp1_input))
	 || (status = device_create_file(&spi->dev, &dev_attr_name))) {
		dev_dbg(&spi->dev, "device_create_file failure.\n");
		goto out_dev_create_file_failed;
	}

	return 0;

out_dev_create_file_failed:
	device_remove_file(&spi->dev, &dev_attr_temp1_input);
	hwmon_device_unregister(p_lm70->hwmon_dev);
out_dev_reg_failed:
	dev_set_drvdata(&spi->dev, NULL);
	kfree(p_lm70);
	return status;
}

static int __devinit lm70_probe(struct spi_device *spi)
{
	/* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */
	if ((spi->mode & (SPI_CPOL | SPI_CPHA)) || !(spi->mode & SPI_3WIRE))
		return -EINVAL;

	return common_probe(spi, LM70_CHIP_LM70);
}

static int __devinit tmp121_probe(struct spi_device *spi)
{
	/* signaling is SPI_MODE_0 with only MISO connected */
	if (spi->mode & (SPI_CPOL | SPI_CPHA))
		return -EINVAL;

	return common_probe(spi, LM70_CHIP_TMP121);
}

static int __devexit lm70_remove(struct spi_device *spi)
{
	struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);

	device_remove_file(&spi->dev, &dev_attr_temp1_input);
	device_remove_file(&spi->dev, &dev_attr_name);
	hwmon_device_unregister(p_lm70->hwmon_dev);
	dev_set_drvdata(&spi->dev, NULL);
	kfree(p_lm70);

	return 0;
}

static struct spi_driver tmp121_driver = {
	.driver = {
		.name	= "tmp121",
		.owner	= THIS_MODULE,
	},
	.probe	= tmp121_probe,
	.remove	= __devexit_p(lm70_remove),
};

static struct spi_driver lm70_driver = {
	.driver = {
		.name	= "lm70",
		.owner	= THIS_MODULE,
	},
	.probe	= lm70_probe,
	.remove	= __devexit_p(lm70_remove),
};

static int __init init_lm70(void)
{
	int ret = spi_register_driver(&lm70_driver);
	if (ret)
		return ret;

	ret = spi_register_driver(&tmp121_driver);
	if (ret)
		spi_unregister_driver(&lm70_driver);

	return ret;
}

static void __exit cleanup_lm70(void)
{
	spi_unregister_driver(&lm70_driver);
	spi_unregister_driver(&tmp121_driver);
}

module_init(init_lm70);
module_exit(cleanup_lm70);

MODULE_AUTHOR("Kaiwan N Billimoria");
MODULE_DESCRIPTION("NS LM70 / TI TMP121/TMP123 Linux driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
e1a8e913 KB	1	/*
	2	* lm70.c
	3	*
	4	* The LM70 is a temperature sensor chip from National Semiconductor (NS).
	5	* Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
	6	*
	7	* The LM70 communicates with a host processor via an SPI/Microwire Bus
	8	* interface. The complete datasheet is available at National's website
	9	* here:
	10	* http://www.national.com/pf/LM/LM70.html
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2 of the License, or
	15	* (at your option) any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public License
	23	* along with this program; if not, write to the Free Software
	24	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	25	*/
	26
	27	#include <linux/init.h>
	28	#include <linux/module.h>
	29	#include <linux/kernel.h>
	30	#include <linux/device.h>
	31	#include <linux/err.h>
	32	#include <linux/sysfs.h>
	33	#include <linux/hwmon.h>
4bfe6604	34	#include <linux/mutex.h>
e1a8e913	35	#include <linux/spi/spi.h>
4bfe6604	36
e1a8e913 KB	37
	38	#define DRVNAME "lm70"
	39
c8ac32e4 ML	40	#define LM70_CHIP_LM70 0 /* original NS LM70 */
	41	#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */
	42
e1a8e913	43	struct lm70 {
1beeffe4	44	struct device *hwmon_dev;
4bfe6604	45	struct mutex lock;
c8ac32e4	46	unsigned int chip;
e1a8e913 KB	47	};
	48
	49	/* sysfs hook function */
	50	static ssize_t lm70_sense_temp(struct device *dev,
	51	struct device_attribute attr, char buf)
	52	{
	53	struct spi_device *spi = to_spi_device(dev);
c8ac32e4	54	int status, val = 0;
e1a8e913 KB	55	u8 rxbuf[2];
	56	s16 raw=0;
	57	struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);
	58
4bfe6604	59	if (mutex_lock_interruptible(&p_lm70->lock))
e1a8e913 KB	60	return -ERESTARTSYS;
	61
	62	/*
	63	* spi_read() requires a DMA-safe buffer; so we use
	64	* spi_write_then_read(), transmitting 0 bytes.
	65	*/
	66	status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
	67	if (status < 0) {
	68	printk(KERN_WARNING
	69	"spi_write_then_read failed with status %d\n", status);
	70	goto out;
	71	}
2b730051 KB	72	raw = (rxbuf[0] << 8) + rxbuf[1];
	73	dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
	74	rxbuf[0], rxbuf[1], raw);
e1a8e913 KB	75
e1a8e913 KB	76	/*
c8ac32e4	77	* LM70:
e1a8e913 KB	78	* The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
	79	* complement value. Only the MSB 11 bits (1 sign + 10 temperature
	80	* bits) are meaningful; the LSB 5 bits are to be discarded.
	81	* See the datasheet.
	82	*
	83	* Further, each bit represents 0.25 degrees Celsius; so, multiply
	84	* by 0.25. Also multiply by 1000 to represent in millidegrees
	85	* Celsius.
	86	* So it's equivalent to multiplying by 0.25 * 1000 = 250.
c8ac32e4 ML	87	*
	88	* TMP121/TMP123:
	89	* 13 bits of 2's complement data, discard LSB 3 bits,
	90	* resolution 0.0625 degrees celsius.
e1a8e913	91	*/
c8ac32e4 ML	92	switch (p_lm70->chip) {
	93	case LM70_CHIP_LM70:
	94	val = ((int)raw / 32) * 250;
	95	break;
	96
	97	case LM70_CHIP_TMP121:
	98	val = ((int)raw / 8) * 625 / 10;
	99	break;
	100	}
	101
67f921d1	102	status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
e1a8e913	103	out:
4bfe6604	104	mutex_unlock(&p_lm70->lock);
e1a8e913 KB	105	return status;
	106	}
	107
	108	static DEVICE_ATTR(temp1_input, S_IRUGO, lm70_sense_temp, NULL);
	109
67f921d1 JD	110	static ssize_t lm70_show_name(struct device *dev, struct device_attribute
	111	devattr, char buf)
	112	{
c8ac32e4 ML	113	struct lm70 *p_lm70 = dev_get_drvdata(dev);
	114	int ret;
	115
	116	switch (p_lm70->chip) {
	117	case LM70_CHIP_LM70:
	118	ret = sprintf(buf, "lm70\n");
	119	break;
	120	case LM70_CHIP_TMP121:
	121	ret = sprintf(buf, "tmp121\n");
	122	break;
	123	default:
	124	ret = -EINVAL;
	125	}
	126	return ret;
67f921d1 JD	127	}
	128
	129	static DEVICE_ATTR(name, S_IRUGO, lm70_show_name, NULL);
	130
e1a8e913 KB	131	/----------------------------------------------------------------------/
e1a8e913 KB	132
c8ac32e4	133	static int __devinit common_probe(struct spi_device *spi, int chip)
e1a8e913 KB	134	{
	135	struct lm70 *p_lm70;
	136	int status;
	137
2b730051 KB	138	/* NOTE: we assume 8-bit words, and convert to 16 bits manually */
2b730051 KB	139
e1a8e913 KB	140	p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL);
	141	if (!p_lm70)
	142	return -ENOMEM;
	143
4bfe6604	144	mutex_init(&p_lm70->lock);
c8ac32e4	145	p_lm70->chip = chip;
e1a8e913 KB	146
e1a8e913 KB	147	/* sysfs hook */
1beeffe4 TJ	148	p_lm70->hwmon_dev = hwmon_device_register(&spi->dev);
1beeffe4 TJ	149	if (IS_ERR(p_lm70->hwmon_dev)) {
e1a8e913	150	dev_dbg(&spi->dev, "hwmon_device_register failed.\n");
1beeffe4	151	status = PTR_ERR(p_lm70->hwmon_dev);
e1a8e913 KB	152	goto out_dev_reg_failed;
	153	}
	154	dev_set_drvdata(&spi->dev, p_lm70);
	155
67f921d1 JD	156	if ((status = device_create_file(&spi->dev, &dev_attr_temp1_input))
67f921d1 JD	157	\|\| (status = device_create_file(&spi->dev, &dev_attr_name))) {
e1a8e913 KB	158	dev_dbg(&spi->dev, "device_create_file failure.\n");
	159	goto out_dev_create_file_failed;
	160	}
	161
	162	return 0;
	163
	164	out_dev_create_file_failed:
67f921d1	165	device_remove_file(&spi->dev, &dev_attr_temp1_input);
1beeffe4	166	hwmon_device_unregister(p_lm70->hwmon_dev);
e1a8e913 KB	167	out_dev_reg_failed:
	168	dev_set_drvdata(&spi->dev, NULL);
	169	kfree(p_lm70);
	170	return status;
	171	}
	172
c8ac32e4 ML	173	static int __devinit lm70_probe(struct spi_device *spi)
	174	{
	175	/* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */
	176	if ((spi->mode & (SPI_CPOL \| SPI_CPHA)) \|\| !(spi->mode & SPI_3WIRE))
	177	return -EINVAL;
	178
	179	return common_probe(spi, LM70_CHIP_LM70);
	180	}
	181
	182	static int __devinit tmp121_probe(struct spi_device *spi)
	183	{
	184	/* signaling is SPI_MODE_0 with only MISO connected */
	185	if (spi->mode & (SPI_CPOL \| SPI_CPHA))
	186	return -EINVAL;
	187
	188	return common_probe(spi, LM70_CHIP_TMP121);
	189	}
	190
41be722b	191	static int __devexit lm70_remove(struct spi_device *spi)
e1a8e913 KB	192	{
	193	struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);
	194
	195	device_remove_file(&spi->dev, &dev_attr_temp1_input);
67f921d1	196	device_remove_file(&spi->dev, &dev_attr_name);
1beeffe4	197	hwmon_device_unregister(p_lm70->hwmon_dev);
e1a8e913 KB	198	dev_set_drvdata(&spi->dev, NULL);
	199	kfree(p_lm70);
	200
	201	return 0;
	202	}
	203
c8ac32e4 ML	204	static struct spi_driver tmp121_driver = {
	205	.driver = {
	206	.name = "tmp121",
	207	.owner = THIS_MODULE,
	208	},
	209	.probe = tmp121_probe,
	210	.remove = __devexit_p(lm70_remove),
	211	};
	212
e1a8e913 KB	213	static struct spi_driver lm70_driver = {
	214	.driver = {
	215	.name = "lm70",
	216	.owner = THIS_MODULE,
	217	},
	218	.probe = lm70_probe,
	219	.remove = __devexit_p(lm70_remove),
	220	};
	221
	222	static int __init init_lm70(void)
	223	{
c8ac32e4 ML	224	int ret = spi_register_driver(&lm70_driver);
	225	if (ret)
	226	return ret;
	227
	228	ret = spi_register_driver(&tmp121_driver);
	229	if (ret)
	230	spi_unregister_driver(&lm70_driver);
	231
	232	return ret;
e1a8e913 KB	233	}
	234
	235	static void __exit cleanup_lm70(void)
	236	{
	237	spi_unregister_driver(&lm70_driver);
c8ac32e4	238	spi_unregister_driver(&tmp121_driver);
e1a8e913 KB	239	}
	240
	241	module_init(init_lm70);
	242	module_exit(cleanup_lm70);
	243
	244	MODULE_AUTHOR("Kaiwan N Billimoria");
c8ac32e4	245	MODULE_DESCRIPTION("NS LM70 / TI TMP121/TMP123 Linux driver");
e1a8e913	246	MODULE_LICENSE("GPL");