/* ltc1710.c - Part of lm_sensors, Linux kernel modules for hardware monitoring Copyright (c) 1999 Frodo Looijaard and Philip Edelbrock 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. */ /* A few notes about the LTC1710: * The LTC1710 is a dual programmable switch. It can be used to turn anything on or off anything which consumes less than 300mA of current and up to 5.5V * The LTC1710 is a very, very simple SMBus device with three possible SMBus addresses (0x58,0x59, or 0x5A). Only SMBus byte writes (command writes) are supported. * Since only writes are supported, READS DON'T WORK! The device plays dead in the event of a read, so this makes detection a bit tricky. * BTW- I can safely say that this driver has been tested under every possible case, so there should be no bugs. :') --Phil */ #include #include #include #include #include "sensors.h" #include "version.h" #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[] = { 0x58, 0x5a, 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(ltc1710); /* The LTC1710 registers */ /* (No registers. [Wow! This thing is SIMPLE!] ) */ /* Initial values */ #define LTC1710_INIT 0 /* Both off */ /* Each client has this additional data */ struct ltc1710_data { int sysctl_id; struct semaphore update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ u8 status; /* 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_ltc1710_init(void); static int __init ltc1710_cleanup(void); static int ltc1710_attach_adapter(struct i2c_adapter *adapter); static int ltc1710_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind); static int ltc1710_detach_client(struct i2c_client *client); static int ltc1710_command(struct i2c_client *client, unsigned int cmd, void *arg); static void ltc1710_inc_use(struct i2c_client *client); static void ltc1710_dec_use(struct i2c_client *client); static void ltc1710_switch1(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void ltc1710_switch2(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void ltc1710_update_client(struct i2c_client *client); /* This is the driver that will be inserted */ static struct i2c_driver ltc1710_driver = { /* name */ "LTC1710 sensor chip driver", /* id */ I2C_DRIVERID_LTC1710, /* flags */ I2C_DF_NOTIFY, /* attach_adapter */ <c1710_attach_adapter, /* detach_client */ <c1710_detach_client, /* command */ <c1710_command, /* inc_use */ <c1710_inc_use, /* dec_use */ <c1710_dec_use }; /* These files are created for each detected LTC1710. 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 ltc1710_dir_table_template[] = { {LTC1710_SYSCTL_SWITCH_1, "switch1", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, <c1710_switch1}, {LTC1710_SYSCTL_SWITCH_2, "switch2", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, <c1710_switch2}, {0} }; /* Used by init/cleanup */ static int __initdata ltc1710_initialized = 0; /* I choose here for semi-static LTC1710 allocation. Complete dynamic allocation could also be used; the code needed for this would probably take more memory than the datastructure takes now. */ static int ltc1710_id = 0; int ltc1710_attach_adapter(struct i2c_adapter *adapter) { return i2c_detect(adapter, &addr_data, ltc1710_detect); } /* This function is called by i2c_detect */ int ltc1710_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind) { int i; struct i2c_client *new_client; struct ltc1710_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 ("ltc1710.o: ltc1710_detect called for an ISA bus adapter?!?\n"); return 0; } #endif if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 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 ltc1710_{read,write}_value. */ if (!(new_client = kmalloc(sizeof(struct i2c_client) + sizeof(struct ltc1710_data), GFP_KERNEL))) { err = -ENOMEM; goto ERROR0; } data = (struct ltc1710_data *) (new_client + 1); new_client->addr = address; new_client->data = data; new_client->adapter = adapter; new_client->driver = <c1710_driver; new_client->flags = 0; /* Now, we would do the remaining detection. But the LTC1710 is plainly impossible to detect! Stupid chip. */ /* Determine the chip type - only one kind supported! */ if (kind <= 0) kind = ltc1710; if (kind == ltc1710) { type_name = "ltc1710"; client_name = "LTC1710 chip"; } else { #ifdef DEBUG printk("ltc1710.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 = ltc1710_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, ltc1710_dir_table_template, THIS_MODULE)) < 0) { err = i; goto ERROR4; } data->sysctl_id = i; 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 ltc1710_detach_client(struct i2c_client *client) { int err; i2c_deregister_entry(((struct ltc1710_data *) (client->data))-> sysctl_id); if ((err = i2c_detach_client(client))) { printk ("ltc1710.o: Client deregistration failed, client not detached.\n"); return err; } kfree(client); return 0; } /* No commands defined yet */ int ltc1710_command(struct i2c_client *client, unsigned int cmd, void *arg) { return 0; } /* Nothing here yet */ void ltc1710_inc_use(struct i2c_client *client) { #ifdef MODULE MOD_INC_USE_COUNT; #endif } /* Nothing here yet */ void ltc1710_dec_use(struct i2c_client *client) { #ifdef MODULE MOD_DEC_USE_COUNT; #endif } void ltc1710_update_client(struct i2c_client *client) { struct ltc1710_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 ltc1710 update\n"); #endif /* data->status = i2c_smbus_read_byte(client); Unfortunately, reads always fail! */ data->last_updated = jiffies; data->valid = 1; } up(&data->update_lock); } void ltc1710_switch1(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct ltc1710_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { ltc1710_update_client(client); results[0] = data->status & 1; *nrels_mag = 1; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { data->status = (data->status & 2) | results[0]; i2c_smbus_write_byte(client, data->status); } } } void ltc1710_switch2(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct ltc1710_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { ltc1710_update_client(client); results[0] = (data->status & 2) >> 1; *nrels_mag = 1; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { data->status = (data->status & 1) | (results[0] << 1); i2c_smbus_write_byte(client, data->status); } } } int __init sensors_ltc1710_init(void) { int res; printk("ltc1710.o version %s (%s)\n", LM_VERSION, LM_DATE); ltc1710_initialized = 0; if ((res = i2c_add_driver(<c1710_driver))) { printk ("ltc1710.o: Driver registration failed, module not inserted.\n"); ltc1710_cleanup(); return res; } ltc1710_initialized++; return 0; } int __init ltc1710_cleanup(void) { int res; if (ltc1710_initialized >= 1) { if ((res = i2c_del_driver(<c1710_driver))) { printk ("ltc1710.o: Driver deregistration failed, module not removed.\n"); return res; } ltc1710_initialized--; } return 0; } EXPORT_NO_SYMBOLS; #ifdef MODULE MODULE_AUTHOR ("Frodo Looijaard and Philip Edelbrock "); MODULE_DESCRIPTION("LTC1710 driver"); int init_module(void) { return sensors_ltc1710_init(); } int cleanup_module(void) { return ltc1710_cleanup(); } #endif /* MODULE */