/* lm75.c - Part of lm_sensors, Linux kernel modules for hardware monitoring Copyright (c) 1998, 1999 Frodo Looijaard 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 #include #include #include #include #define LM_DATE "20011118" #define LM_VERSION "2.6.2" #include #ifdef MODULE_LICENSE MODULE_LICENSE("GPL"); #endif #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,2,18)) || \ (LINUX_VERSION_CODE == KERNEL_VERSION(2,3,0)) #define init_MUTEX(s) do { *(s) = MUTEX; } while(0) #endif #ifndef THIS_MODULE #define THIS_MODULE NULL #endif /* Addresses to scan */ static unsigned short normal_i2c[] = { SENSORS_I2C_END }; static unsigned short normal_i2c_range[] = { 0x48, 0x4f, SENSORS_I2C_END }; static unsigned int normal_isa[] = { SENSORS_ISA_END }; static unsigned int normal_isa_range[] = { SENSORS_ISA_END }; /* Insmod parameters */ SENSORS_INSMOD_1(lm75); /* Many LM75 constants specified below */ /* The LM75 registers */ #define LM75_REG_TEMP 0x00 #define LM75_REG_CONF 0x01 #define LM75_REG_TEMP_HYST 0x02 #define LM75_REG_TEMP_OS 0x03 /* 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 TEMP_FROM_REG(val) ((((val & 0x7fff) >> 7) * 5) | ((val & 0x8000)?-256:0)) #define TEMP_TO_REG(val) (SENSORS_LIMIT((val<0?(0x200+((val)/5))<<7:(((val) + 2) / 5) << 7),0,0xffff)) /* Initial values */ #define LM75_INIT_TEMP_OS 600 #define LM75_INIT_TEMP_HYST 500 /* Each client has this additional data */ struct lm75_data { int sysctl_id; struct semaphore update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ u16 temp, temp_os, temp_hyst; /* Register values */ }; #ifdef MODULE extern int init_module(void); extern int cleanup_module(void); #endif /* MODULE */ #ifdef MODULE static #else extern #endif int __init sensors_lm75_init(void); static int __init lm75_cleanup(void); static int lm75_attach_adapter(struct i2c_adapter *adapter); static int lm75_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind); static void lm75_init_client(struct i2c_client *client); static int lm75_detach_client(struct i2c_client *client); static int lm75_command(struct i2c_client *client, unsigned int cmd, void *arg); static void lm75_inc_use(struct i2c_client *client); static void lm75_dec_use(struct i2c_client *client); static u16 swap_bytes(u16 val); static int lm75_read_value(struct i2c_client *client, u8 reg); static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); static void lm75_temp(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void lm75_update_client(struct i2c_client *client); /* This is the driver that will be inserted */ static struct i2c_driver lm75_driver = { /* name */ "LM75 sensor chip driver", /* id */ I2C_DRIVERID_LM75, /* flags */ I2C_DF_NOTIFY, /* attach_adapter */ &lm75_attach_adapter, /* detach_client */ &lm75_detach_client, /* command */ &lm75_command, /* inc_use */ &lm75_inc_use, /* dec_use */ &lm75_dec_use }; /* These files are created for each detected LM75. This is just a template; though at first sight, you might think we could use a statically allocated list, we need some way to get back to the parent - which is done through one of the 'extra' fields which are initialized when a new copy is allocated. */ static ctl_table lm75_dir_table_template[] = { {LM75_SYSCTL_TEMP, "temp", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &lm75_temp}, {0} }; /* Used by init/cleanup */ static int __initdata lm75_initialized = 0; static int lm75_id = 0; int lm75_attach_adapter(struct i2c_adapter *adapter) { return i2c_detect(adapter, &addr_data, lm75_detect); } /* This function is called by i2c_detect */ int lm75_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind) { int i, cur, conf, hyst, os; struct i2c_client *new_client; struct lm75_data *data; int err = 0; const char *type_name, *client_name; /* Make sure we aren't probing the ISA bus!! This is just a safety check at this moment; i2c_detect really won't call us. */ #ifdef DEBUG if (i2c_is_isa_adapter(adapter)) { printk ("lm75.o: lm75_detect called for an ISA bus adapter?!?\n"); return 0; } #endif if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) goto ERROR0; /* 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 lm75_{read,write}_value. */ if (!(new_client = kmalloc(sizeof(struct i2c_client) + sizeof(struct lm75_data), GFP_KERNEL))) { err = -ENOMEM; goto ERROR0; } data = (struct lm75_data *) (new_client + 1); new_client->addr = address; new_client->data = data; new_client->adapter = adapter; new_client->driver = &lm75_driver; new_client->flags = 0; /* Now, we do the remaining detection. It is lousy. */ if (kind < 0) { cur = i2c_smbus_read_word_data(new_client, 0); conf = i2c_smbus_read_byte_data(new_client, 1); hyst = i2c_smbus_read_word_data(new_client, 2); os = i2c_smbus_read_word_data(new_client, 3); for (i = 0; i <= 0x1f; i++) if ( (i2c_smbus_read_byte_data (new_client, i * 8 + 1) != conf) || (i2c_smbus_read_word_data (new_client, i * 8 + 2) != hyst) || (i2c_smbus_read_word_data (new_client, i * 8 + 3) != os)) goto ERROR1; } /* Determine the chip type - only one kind supported! */ if (kind <= 0) kind = lm75; if (kind == lm75) { type_name = "lm75"; client_name = "LM75 chip"; } else { #ifdef DEBUG printk("lm75.o: Internal error: unknown kind (%d)?!?", kind); #endif goto ERROR1; } /* Fill in the remaining client fields and put it into the global list */ strcpy(new_client->name, client_name); new_client->id = lm75_id++; 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 ERROR3; /* Register a new directory entry with module sensors */ if ((i = i2c_register_entry(new_client, type_name, lm75_dir_table_template, THIS_MODULE)) < 0) { err = i; goto ERROR4; } data->sysctl_id = i; lm75_init_client(new_client); return 0; /* OK, this is not exactly good programming practice, usually. But it is very code-efficient in this case. */ ERROR4: i2c_detach_client(new_client); ERROR3: ERROR1: kfree(new_client); ERROR0: return err; } int lm75_detach_client(struct i2c_client *client) { int err; #ifdef MODULE if (MOD_IN_USE) return -EBUSY; #endif i2c_deregister_entry(((struct lm75_data *) (client->data))-> sysctl_id); if ((err = i2c_detach_client(client))) { printk ("lm75.o: Client deregistration failed, client not detached.\n"); return err; } kfree(client); return 0; } /* No commands defined yet */ int lm75_command(struct i2c_client *client, unsigned int cmd, void *arg) { return 0; } /* Nothing here yet */ void lm75_inc_use(struct i2c_client *client) { #ifdef MODULE MOD_INC_USE_COUNT; #endif } /* Nothing here yet */ void lm75_dec_use(struct i2c_client *client) { #ifdef MODULE MOD_DEC_USE_COUNT; #endif } u16 swap_bytes(u16 val) { return (val >> 8) | (val << 8); } /* All registers are word-sized, except for the configuration register. LM75 uses a high-byte first convention, which is exactly opposite to the usual practice. */ int lm75_read_value(struct i2c_client *client, u8 reg) { if (reg == LM75_REG_CONF) return i2c_smbus_read_byte_data(client, reg); else return swap_bytes(i2c_smbus_read_word_data(client, reg)); } /* All registers are word-sized, except for the configuration register. LM75 uses a high-byte first convention, which is exactly opposite to the usual practice. */ int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) { if (reg == LM75_REG_CONF) return i2c_smbus_write_byte_data(client, reg, value); else return i2c_smbus_write_word_data(client, reg, swap_bytes(value)); } void lm75_init_client(struct i2c_client *client) { /* Initialize the LM75 chip */ lm75_write_value(client, LM75_REG_TEMP_OS, TEMP_TO_REG(LM75_INIT_TEMP_OS)); lm75_write_value(client, LM75_REG_TEMP_HYST, TEMP_TO_REG(LM75_INIT_TEMP_HYST)); lm75_write_value(client, LM75_REG_CONF, 0); } void lm75_update_client(struct i2c_client *client) { struct lm75_data *data = client->data; down(&data->update_lock); if ((jiffies - data->last_updated > HZ + HZ / 2) || (jiffies < data->last_updated) || !data->valid) { #ifdef DEBUG printk("Starting lm75 update\n"); #endif data->temp = lm75_read_value(client, LM75_REG_TEMP); data->temp_os = lm75_read_value(client, LM75_REG_TEMP_OS); data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST); data->last_updated = jiffies; data->valid = 1; } up(&data->update_lock); } void lm75_temp(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct lm75_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 1; else if (operation == SENSORS_PROC_REAL_READ) { lm75_update_client(client); results[0] = TEMP_FROM_REG(data->temp_os); results[1] = TEMP_FROM_REG(data->temp_hyst); results[2] = TEMP_FROM_REG(data->temp); *nrels_mag = 3; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { data->temp_os = TEMP_TO_REG(results[0]); lm75_write_value(client, LM75_REG_TEMP_OS, data->temp_os); } if (*nrels_mag >= 2) { data->temp_hyst = TEMP_TO_REG(results[1]); lm75_write_value(client, LM75_REG_TEMP_HYST, data->temp_hyst); } } } int __init sensors_lm75_init(void) { int res; printk("lm75.o version %s (%s)\n", LM_VERSION, LM_DATE); lm75_initialized = 0; if ((res = i2c_add_driver(&lm75_driver))) { printk ("lm75.o: Driver registration failed, module not inserted.\n"); lm75_cleanup(); return res; } lm75_initialized++; return 0; } int __init lm75_cleanup(void) { int res; if (lm75_initialized >= 1) { if ((res = i2c_del_driver(&lm75_driver))) { printk ("lm75.o: Driver deregistration failed, module not removed.\n"); return res; } lm75_initialized--; } return 0; } EXPORT_NO_SYMBOLS; #ifdef MODULE MODULE_AUTHOR("Frodo Looijaard "); MODULE_DESCRIPTION("LM75 driver"); int init_module(void) { return sensors_lm75_init(); } int cleanup_module(void) { return lm75_cleanup(); } #endif /* MODULE */