/*
 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
 *             monitoring
 * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
 *                         Jean Delvare <khali@linux-fr.org>
 *
 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
 * It reports up to two temperatures (its own plus up to
 * one external one). Complete datasheet can be
 * obtained from Maxim's website at:
 *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/i2c-sensor.h>


static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
					0x29, 0x2a, 0x2b,
					0x4c, 0x4d, 0x4e,
					I2C_CLIENT_END };
static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };

/*
 * Insmod parameters
 */

SENSORS_INSMOD_1(max1619);

/*
 * The MAX1619 registers
 */

#define MAX1619_REG_R_MAN_ID		0xFE
#define MAX1619_REG_R_CHIP_ID		0xFF
#define MAX1619_REG_R_CONFIG		0x03
#define MAX1619_REG_W_CONFIG		0x09
#define MAX1619_REG_R_CONVRATE		0x04
#define MAX1619_REG_W_CONVRATE		0x0A
#define MAX1619_REG_R_STATUS		0x02
#define MAX1619_REG_R_LOCAL_TEMP	0x00
#define MAX1619_REG_R_REMOTE_TEMP	0x01
#define MAX1619_REG_R_REMOTE_HIGH	0x07
#define MAX1619_REG_W_REMOTE_HIGH	0x0D
#define MAX1619_REG_R_REMOTE_LOW	0x08
#define MAX1619_REG_W_REMOTE_LOW	0x0E
#define MAX1619_REG_R_REMOTE_CRIT	0x10
#define MAX1619_REG_W_REMOTE_CRIT	0x12
#define MAX1619_REG_R_TCRIT_HYST	0x11
#define MAX1619_REG_W_TCRIT_HYST	0x13

/*
 * Conversions and various macros
 */

#define TEMP_FROM_REG(val)	((val & 0x80 ? val-0x100 : val) * 1000)
#define TEMP_TO_REG(val)	((val < 0 ? val+0x100*1000 : val) / 1000)

/*
 * Functions declaration
 */

static int max1619_attach_adapter(struct i2c_adapter *adapter);
static int max1619_detect(struct i2c_adapter *adapter, int address,
	int kind);
static void max1619_init_client(struct i2c_client *client);
static int max1619_detach_client(struct i2c_client *client);
static struct max1619_data *max1619_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver max1619_driver = {
	.owner		= THIS_MODULE,
	.name		= "max1619",
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= max1619_attach_adapter,
	.detach_client	= max1619_detach_client,
};

/*
 * Client data (each client gets its own)
 */

struct max1619_data {
	struct i2c_client client;
	struct semaphore update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	u8 temp_input1; /* local */
	u8 temp_input2, temp_low2, temp_high2; /* remote */
	u8 temp_crit2;
	u8 temp_hyst2;
	u8 alarms; 
};

/*
 * Sysfs stuff
 */

#define show_temp(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
	struct max1619_data *data = max1619_update_device(dev); \
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
}
show_temp(temp_input1);
show_temp(temp_input2);
show_temp(temp_low2);
show_temp(temp_high2);
show_temp(temp_crit2);
show_temp(temp_hyst2);

#define set_temp2(value, reg) \
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct max1619_data *data = i2c_get_clientdata(client); \
	long val = simple_strtol(buf, NULL, 10); \
 \
	down(&data->update_lock); \
	data->value = TEMP_TO_REG(val); \
	i2c_smbus_write_byte_data(client, reg, data->value); \
	up(&data->update_lock); \
	return count; \
}

set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct max1619_data *data = max1619_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
	set_temp_low2);
static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
	set_temp_high2);
static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
	set_temp_crit2);