hwmon: New AD7416, AD7417 and AD7418 driver

A driver for the Analog Devices AD7416, AD7417 and AD7418 chips.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

drivers/hwmon/Kconfig

@@ -39,6 +39,16 @@ config SENSORS_ABITUGURU
 	  This driver can also be built as a module.  If so, the module
 	  will be called abituguru.
 
+config SENSORS_AD7418
+	tristate "Analog Devices AD7416, AD7417 and AD7418"
+	depends on HWMON && I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Analog Devices
+	  AD7416, AD7417 and AD7418 temperature monitoring chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called ad7418.
+
 config SENSORS_ADM1021
 	tristate "Analog Devices ADM1021 and compatibles"
 	depends on HWMON && I2C

drivers/hwmon/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_SENSORS_W83781D)	+= w83781d.o
 obj-$(CONFIG_SENSORS_W83791D)	+= w83791d.o
 
 obj-$(CONFIG_SENSORS_ABITUGURU)	+= abituguru.o
+obj-$(CONFIG_SENSORS_AD7418)	+= ad7418.o
 obj-$(CONFIG_SENSORS_ADM1021)	+= adm1021.o
 obj-$(CONFIG_SENSORS_ADM1025)	+= adm1025.o
 obj-$(CONFIG_SENSORS_ADM1026)	+= adm1026.o

drivers/hwmon/ad7418.c

+/*
+ * An hwmon driver for the Analog Devices AD7416/17/18
+ * Copyright (C) 2006-07 Tower Technologies
+ *
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * Based on lm75.c
+ * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
+ *
+ * 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 - version 2.
+ */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+
+#include "lm75.h"
+
+#define DRV_VERSION "0.3"
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x28, I2C_CLIENT_END };
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_3(ad7416, ad7417, ad7418);
+
+/* AD7418 registers */
+#define AD7418_REG_TEMP_IN	0x00
+#define AD7418_REG_CONF		0x01
+#define AD7418_REG_TEMP_HYST	0x02
+#define AD7418_REG_TEMP_OS	0x03
+#define AD7418_REG_ADC		0x04
+#define AD7418_REG_CONF2	0x05
+
+#define AD7418_REG_ADC_CH(x)	((x) << 5)
+#define AD7418_CH_TEMP		AD7418_REG_ADC_CH(0)
+
+static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
+					AD7418_REG_TEMP_HYST,
+					AD7418_REG_TEMP_OS };
+
+struct ad7418_data {
+	struct i2c_client	client;
+	struct class_device	*class_dev;
+	struct attribute_group	attrs;
+	enum chips		type;
+	struct mutex		lock;
+	int			adc_max;	/* number of ADC channels */
+	char			valid;
+	unsigned long		last_updated;	/* In jiffies */
+	s16			temp[3];	/* Register values */
+	u16			in[4];
+};
+
+static int ad7418_attach_adapter(struct i2c_adapter *adapter);
+static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind);
+static int ad7418_detach_client(struct i2c_client *client);
+
+static struct i2c_driver ad7418_driver = {
+	.driver = {
+		.name	= "ad7418",
+	},
+	.attach_adapter	= ad7418_attach_adapter,
+	.detach_client	= ad7418_detach_client,
+};
+
+/* All registers are word-sized, except for the configuration registers.
+ * AD7418 uses a high-byte first convention. Do NOT use those functions to
+ * access the configuration registers CONF and CONF2, as they are byte-sized.
+ */
+static inline int ad7418_read(struct i2c_client *client, u8 reg)
+{
+	return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
+{
+	return i2c_smbus_write_word_data(client, reg, swab16(value));
+}
+
+static void ad7418_init_client(struct i2c_client *client)
+{
+	struct ad7418_data *data = i2c_get_clientdata(client);
+
+	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
+	if (reg < 0) {
+		dev_err(&client->dev, "cannot read configuration register\n");
+	} else {
+		dev_info(&client->dev, "configuring for mode 1\n");
+		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
+
+		if (data->type == ad7417 || data->type == ad7418)
+			i2c_smbus_write_byte_data(client,
+						AD7418_REG_CONF2, 0x00);
+	}
+}
+
+static struct ad7418_data *ad7418_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ad7418_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->lock);
+
+	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+		|| !data->valid) {
+		u8 cfg;
+		int i, ch;
+
+		/* read config register and clear channel bits */
+		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
+		cfg &= 0x1F;
+
+		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
+						cfg | AD7418_CH_TEMP);
+		udelay(30);
+
+		for (i = 0; i < 3; i++) {
+			data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
+		}
+
+		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
+			i2c_smbus_write_byte_data(client,
+					AD7418_REG_CONF,
+					cfg | AD7418_REG_ADC_CH(ch));
+
+			udelay(15);
+			data->in[data->adc_max - 1 - i] =
+				ad7418_read(client, AD7418_REG_ADC);
+		}
+
+		/* restore old configuration value */
+		ad7418_write(client, AD7418_REG_CONF, cfg);
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->lock);
+
+	return data;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
+			char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct ad7418_data *data = ad7418_update_device(dev);
+	return sprintf(buf, "%d\n",
+		LM75_TEMP_FROM_REG(data->temp[attr->index]));
+}
+
+static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
+			char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct ad7418_data *data = ad7418_update_device(dev);
+
+	return sprintf(buf, "%d\n",
+		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
+}
+
+static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
+			const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ad7418_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	mutex_lock(&data->lock);
+	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
+	ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
+	mutex_unlock(&data->lock);
+	return count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+				show_temp, set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+				show_temp, set_temp, 2);
+
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
+
+static int ad7418_attach_adapter(struct i2c_adapter *adapter)
+{
+	if (!(adapter->class & I2C_CLASS_HWMON))
+		return 0;
+	return i2c_probe(adapter, &addr_data, ad7418_detect);
+}
+
+static struct attribute *ad7416_attributes[] = {
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	NULL
+};
+
+static struct attribute *ad7417_attributes[] = {
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_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,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	NULL
+};
+
+static struct attribute *ad7418_attributes[] = {
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	NULL
+};
+
+static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *client;
+	struct ad7418_data *data;
+	int err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+					I2C_FUNC_SMBUS_WORD_DATA))
+		goto exit;
+
+	if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	client = &data->client;
+	client->addr = address;
+	client->adapter = adapter;
+	client->driver = &ad7418_driver;
+
+	i2c_set_clientdata(client, data);
+
+	mutex_init(&data->lock);
+
+	/* AD7418 has a curious behaviour on registers 6 and 7. They
+	 * both always read 0xC071 and are not documented on the datasheet.
+	 * We use them to detect the chip.
+	 */
+	if (kind <= 0) {
+		int reg, reg6, reg7;
+
+		/* the AD7416 lies within this address range, but I have
+		 * no means to check.
+		 */
+		if (address >= 0x48 && address <= 0x4f) {
+			/* XXX add tests for AD7416 here */
+			/* data->type = ad7416; */
+		}
+		/* here we might have AD7417 or AD7418 */
+		else if (address >= 0x28 && address <= 0x2f) {
+			reg6 = i2c_smbus_read_word_data(client, 0x06);
+			reg7 = i2c_smbus_read_word_data(client, 0x07);
+
+			if (address == 0x28 && reg6 == 0xC071 && reg7 == 0xC071)
+				data->type = ad7418;
+
+			/* XXX add tests for AD7417 here */
+
+
+			/* both AD7417 and AD7418 have bits 0-5 of
+			 * the CONF2 register at 0
+			 */
+			reg = i2c_smbus_read_byte_data(client,
+							AD7418_REG_CONF2);
+			if (reg & 0x3F)
+				data->type = any_chip; /* detection failed */
+		}
+	} else {
+		dev_dbg(&adapter->dev, "detection forced\n");
+	}
+
+	if (kind > 0)
+		data->type = kind;
+	else if (kind < 0 && data->type == any_chip) {
+		err = -ENODEV;
+		goto exit_free;
+	}
+
+	switch (data->type) {
+	case any_chip:
+	case ad7416:
+		data->adc_max = 0;
+		data->attrs.attrs = ad7416_attributes;
+		strlcpy(client->name, "ad7416", I2C_NAME_SIZE);
+		break;
+
+	case ad7417:
+		data->adc_max = 4;
+		data->attrs.attrs = ad7417_attributes;
+		strlcpy(client->name, "ad7417", I2C_NAME_SIZE);
+		break;
+
+	case ad7418:
+		data->adc_max = 1;
+		data->attrs.attrs = ad7418_attributes;
+		strlcpy(client->name, "ad7418", I2C_NAME_SIZE);
+		break;
+	}
+
+	if ((err = i2c_attach_client(client)))
+		goto exit_free;
+
+	dev_info(&client->dev, "%s chip found\n", client->name);
+
+	/* Initialize the AD7418 chip */
+	ad7418_init_client(client);
+
+	/* Register sysfs hooks */
+	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
+		goto exit_detach;
+
+	data->class_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->class_dev)) {
+		err = PTR_ERR(data->class_dev);
+		goto exit_remove;
+	}
+
+	return 0;
+
+exit_remove:
+	sysfs_remove_group(&client->dev.kobj, &data->attrs);
+exit_detach:
+	i2c_detach_client(client);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int ad7418_detach_client(struct i2c_client *client)
+{
+	struct ad7418_data *data = i2c_get_clientdata(client);
+	hwmon_device_unregister(data->class_dev);
+	sysfs_remove_group(&client->dev.kobj, &data->attrs);
+	i2c_detach_client(client);
+	kfree(data);
+	return 0;
+}
+
+static int __init ad7418_init(void)
+{
+	return i2c_add_driver(&ad7418_driver);
+}
+
+static void __exit ad7418_exit(void)
+{
+	i2c_del_driver(&ad7418_driver);
+}
+
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_DESCRIPTION("AD7416/17/18 driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(ad7418_init);
+module_exit(ad7418_exit);