diff options
Diffstat (limited to 'drivers/i2c/chips/ds1621.c')
| -rw-r--r-- | drivers/i2c/chips/ds1621.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/i2c/chips/ds1621.c b/drivers/i2c/chips/ds1621.c new file mode 100644 index 000000000000..bb1fefb2162e --- /dev/null +++ b/drivers/i2c/chips/ds1621.c @@ -0,0 +1,341 @@ +/* + ds1621.c - Part of lm_sensors, Linux kernel modules for hardware + monitoring + Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23 + based on lm75.c by Frodo Looijaard <frodol@dds.nl> + Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with + the help of Jean Delvare <khali@linux-fr.org> + + 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> +#include "lm75.h" + +/* Addresses to scan */ +static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, + 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; +static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; + +/* Insmod parameters */ +SENSORS_INSMOD_1(ds1621); +static int polarity = -1; +module_param(polarity, int, 0); +MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); + +/* Many DS1621 constants specified below */ +/* Config register used for detection */ +/* 7 6 5 4 3 2 1 0 */ +/* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ +#define DS1621_REG_CONFIG_NVB 0x10 +#define DS1621_REG_CONFIG_POLARITY 0x02 +#define DS1621_REG_CONFIG_1SHOT 0x01 +#define DS1621_REG_CONFIG_DONE 0x80 + +/* The DS1621 registers */ +#define DS1621_REG_TEMP 0xAA /* word, RO */ +#define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */ +#define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */ +#define DS1621_REG_CONF 0xAC /* byte, RW */ +#define DS1621_COM_START 0xEE /* no data */ +#define DS1621_COM_STOP 0x22 /* no data */ + +/* The DS1621 configuration register */ +#define DS1621_ALARM_TEMP_HIGH 0x40 +#define DS1621_ALARM_TEMP_LOW 0x20 + +/* Conversions. Rounding and limit checking is only done on the TO_REG + variants. Note that you should be a bit careful with which arguments + these macros are called: arguments may be evaluated more than once. + Fixing this is just not worth it. */ +#define ALARMS_FROM_REG(val) ((val) & \ + (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) + +/* Each client has this additional data */ +struct ds1621_data { + struct i2c_client client; + struct semaphore update_lock; + char valid; /* !=0 if following fields are valid */ + unsigned long last_updated; /* In jiffies */ + + u16 temp, temp_min, temp_max; /* Register values, word */ + u8 conf; /* Register encoding, combined */ +}; + +static int ds1621_attach_adapter(struct i2c_adapter *adapter); +static int ds1621_detect(struct i2c_adapter *adapter, int address, + int kind); +static void ds1621_init_client(struct i2c_client *client); +static int ds1621_detach_client(struct i2c_client *client); +static struct ds1621_data *ds1621_update_client(struct device *dev); + +/* This is the driver that will be inserted */ +static struct i2c_driver ds1621_driver = { + .owner = THIS_MODULE, + .name = "ds1621", + .id = I2C_DRIVERID_DS1621, + .flags = I2C_DF_NOTIFY, + .attach_adapter = ds1621_attach_adapter, + .detach_client = ds1621_detach_client, +}; + +/* All registers are word-sized, except for the configuration register. + DS1621 uses a high-byte first convention, which is exactly opposite to + the usual practice. */ +static int ds1621_read_value(struct i2c_client *client, u8 reg) +{ + if (reg == DS1621_REG_CONF) + return i2c_smbus_read_byte_data(client, reg); + else + return swab16(i2c_smbus_read_word_data(client, reg)); +} + +/* All registers are word-sized, except for the configuration register. + DS1621 uses a high-byte first convention, which is exactly opposite to + the usual practice. */ +static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) +{ + if (reg == DS1621_REG_CONF) + return i2c_smbus_write_byte_data(client, reg, value); + else + return i2c_smbus_write_word_data(client, reg, swab16(value)); +} + +static void ds1621_init_client(struct i2c_client *client) +{ + int reg = ds1621_read_value(client, DS1621_REG_CONF); + /* switch to continous conversion mode */ + reg &= ~ DS1621_REG_CONFIG_1SHOT; + + /* setup output polarity */ + if (polarity == 0) + reg &= ~DS1621_REG_CONFIG_POLARITY; + else if (polarity == 1) + reg |= DS1621_REG_CONFIG_POLARITY; + + ds1621_write_value(client, DS1621_REG_CONF, reg); + + /* start conversion */ + i2c_smbus_write_byte(client, DS1621_COM_START); +} + +#define show(value) \ +static ssize_t show_##value(struct device *dev, char *buf) \ +{ \ + struct ds1621_data *data = ds1621_update_client(dev); \ + return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ +} + +show(temp); +show(temp_min); +show(temp_max); + +#define set_temp(suffix, value, reg) \ +static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \ + size_t count) \ +{ \ + struct i2c_client *client = to_i2c_client(dev); \ + struct ds1621_data *data = ds1621_update_client(dev); \ + u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \ + \ + down(&data->update_lock); \ + data->value = val; \ + ds1621_write_value(client, reg, data->value); \ + up(&data->update_lock); \ + return count; \ +} + +set_temp(min, temp_min, DS1621_REG_TEMP_MIN); +set_temp(max, temp_max, DS1621_REG_TEMP_MAX); + +static ssize_t show_alarms(struct device *dev, char *buf) +{ + struct ds1621_data *data = ds1621_update_client(dev); + return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); +} + +static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); +static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL); +static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min); +static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); + + +static int ds1621_attach_adapter(struct i2c_adapter *adapter) +{ + return i2c_detect(adapter, &addr_data, ds1621_detect); +} + +/* This function is called by i2c_detect */ +int ds1621_detect(struct i2c_adapter *adapter, int address, + int kind) +{ + int conf, temp; + struct i2c_client *new_client; + struct ds1621_data *data; + int err = 0; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA + | I2C_FUNC_SMBUS_WORD_DATA + | I2C_FUNC_SMBUS_WRITE_BYTE)) + goto exit; + + /* OK. For now, we presume we have a valid client. We now create the + client structure, even though we cannot fill it completely yet. + But it allows us to access ds1621_{read,write}_value. */ + if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { + err = -ENOMEM; + goto exit; + } + memset(data, 0, sizeof(struct ds1621_data)); + + new_client = &data->client; + i2c_set_clientdata(new_client, data); + new_client->addr = address; + new_client->adapter = adapter; + new_client->driver = &ds1621_driver; + new_client->flags = 0; + + + /* Now, we do the remaining detection. It is lousy. */ + if (kind < 0) { + /* The NVB bit should be low if no EEPROM write has been + requested during the latest 10ms, which is highly + improbable in our case. */ + conf = ds1621_read_value(new_client, DS1621_REG_CONF); + if (conf & DS1621_REG_CONFIG_NVB) + goto exit_free; + /* The 7 lowest bits of a temperature should always be 0. */ + temp = ds1621_read_value(new_client, DS1621_REG_TEMP); + if (temp & 0x007f) + goto exit_free; + temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN); + if (temp & 0x007f) + goto exit_free; + temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX); + if (temp & 0x007f) + goto exit_free; + } + + /* Determine the chip type - only one kind supported! */ + if (kind <= 0) + kind = ds1621; + + /* Fill in remaining client fields and put it into the global list */ + strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE); + data->valid = 0; + init_MUTEX(&data->update_lock); + + /* Tell the I2C layer a new client has arrived */ + if ((err = i2c_attach_client(new_client))) + goto exit_free; + + /* Initialize the DS1621 chip */ + ds1621_init_client(new_client); + + /* Register sysfs hooks */ + device_create_file(&new_client->dev, &dev_attr_alarms); + device_create_file(&new_client->dev, &dev_attr_temp1_input); + device_create_file(&new_client->dev, &dev_attr_temp1_min); + device_create_file(&new_client->dev, &dev_attr_temp1_max); + + return 0; + +/* OK, this is not exactly good programming practice, usually. But it is + very code-efficient in this case. */ + exit_free: + kfree(data); + exit: + return err; +} + +static int ds1621_detach_client(struct i2c_client *client) +{ + int err; + + if ((err = i2c_detach_client(client))) { + dev_err(&client->dev, "Client deregistration failed, " + "client not detached.\n"); + return err; + } + + kfree(i2c_get_clientdata(client)); + + return 0; +} + + +static struct ds1621_data *ds1621_update_client(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds1621_data *data = i2c_get_clientdata(client); + u8 new_conf; + + down(&data->update_lock); + + if (time_after(jiffies, data->last_updated + HZ + HZ / 2) + || !data->valid) { + + dev_dbg(&client->dev, "Starting ds1621 update\n"); + + data->conf = ds1621_read_value(client, DS1621_REG_CONF); + + data->temp = ds1621_read_value(client, DS1621_REG_TEMP); + + data->temp_min = ds1621_read_value(client, + DS1621_REG_TEMP_MIN); + data->temp_max = ds1621_read_value(client, + DS1621_REG_TEMP_MAX); + + /* reset alarms if neccessary */ + new_conf = data->conf; + if (data->temp < data->temp_min) + new_conf &= ~DS1621_ALARM_TEMP_LOW; + if (data->temp > data->temp_max) + new_conf &= ~DS1621_ALARM_TEMP_HIGH; + if (data->conf != new_conf) + ds1621_write_value(client, DS1621_REG_CONF, + new_conf); + + data->last_updated = jiffies; + data->valid = 1; + } + + up(&data->update_lock); + + return data; +} + +static int __init ds1621_init(void) +{ + return i2c_add_driver(&ds1621_driver); +} + +static void __exit ds1621_exit(void) +{ + i2c_del_driver(&ds1621_driver); +} + + +MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); +MODULE_DESCRIPTION("DS1621 driver"); +MODULE_LICENSE("GPL"); + +module_init(ds1621_init); +module_exit(ds1621_exit); |