/* pcf8591.c - Part of lm_sensors, Linux kernel modules for hardware monitoring Copyright (c) 2001 Aurelien Jarno 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 #include "version.h" /* 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(pcf8591); /* The PCF8591 control byte */ /* 7 6 5 4 3 2 1 0 */ /* | 0 |AOEF| AIP | 0 |AINC| AICH | */ #define PCF8591_CONTROL_BYTE_AOEF 0x40 /* Analog Output Enable Flag */ /* (analog output active if 1) */ #define PCF8591_CONTROL_BYTE_AIP 0x30 /* Analog Input Programming */ /* 0x00 = four single ended inputs */ /* 0x10 = three differential inputs */ /* 0x20 = single ended and differential mixed */ /* 0x30 = two differential inputs */ #define PCF8591_CONTROL_BYTE_AINC 0x04 /* Autoincrement Flag */ /* (switch on if 1) */ #define PCF8591_CONTROL_BYTE_AICH 0x03 /* Analog Output Enable Flag */ /* 0x00 = channel 0 */ /* 0x01 = channel 1 */ /* 0x02 = channel 2 */ /* 0x03 = channel 3 */ /* Initial values */ #define PCF8591_INIT_CONTROL_BYTE (PCF8591_CONTROL_BYTE_AOEF | PCF8591_CONTROL_BYTE_AINC) /* DAC out enabled, four single ended inputs, autoincrement */ #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */ /* Conversions. */ #define REG_TO_SIGNED(reg) (reg & 0x80)?(reg - 256):(reg) /* Convert signed 8 bit value to signed value */ struct pcf8591_data { struct semaphore lock; int sysctl_id; enum chips type; struct semaphore update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ u8 control_byte; u8 ch[4]; u8 aout; }; static int pcf8591_attach_adapter(struct i2c_adapter *adapter); static int pcf8591_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind); static int pcf8591_detach_client(struct i2c_client *client); static void pcf8591_update_client(struct i2c_client *client); static void pcf8591_init_client(struct i2c_client *client); static void pcf8591_ain_conf(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void pcf8591_ain(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void pcf8591_aout_enable(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); static void pcf8591_aout(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results); /* This is the driver that will be inserted */ static struct i2c_driver pcf8591_driver = { .owner = THIS_MODULE, .name = "PCF8591 sensor chip driver", .id = I2C_DRIVERID_PCF8591, .flags = I2C_DF_NOTIFY, .attach_adapter = pcf8591_attach_adapter, .detach_client = pcf8591_detach_client, }; static int pcf8591_id = 0; /* The /proc/sys entries */ /* -- SENSORS SYSCTL START -- */ #define PCF8591_SYSCTL_AIN_CONF 1000 /* Analog input configuration */ #define PCF8591_SYSCTL_CH0 1001 /* Input channel 1 */ #define PCF8591_SYSCTL_CH1 1002 /* Input channel 2 */ #define PCF8591_SYSCTL_CH2 1003 /* Input channel 3 */ #define PCF8591_SYSCTL_CH3 1004 /* Input channel 4 */ #define PCF8591_SYSCTL_AOUT_ENABLE 1005 /* Analog output enable flag */ #define PCF8591_SYSCTL_AOUT 1006 /* Analog output */ /* -- SENSORS SYSCTL END -- */ /* These files are created for each detected PCF8591. 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 pcf8591_dir_table_template[] = { {PCF8591_SYSCTL_AIN_CONF, "ain_conf", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_ain_conf}, {PCF8591_SYSCTL_CH0, "ch0", NULL, 0, 0444, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_ain}, {PCF8591_SYSCTL_CH1, "ch1", NULL, 0, 0444, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_ain}, {PCF8591_SYSCTL_CH2, "ch2", NULL, 0, 0444, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_ain}, {PCF8591_SYSCTL_CH3, "ch3", NULL, 0, 0444, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_ain}, {PCF8591_SYSCTL_AOUT_ENABLE, "aout_enable", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_aout_enable}, {PCF8591_SYSCTL_AOUT, "aout", NULL, 0, 0644, NULL, &i2c_proc_real, &i2c_sysctl_real, NULL, &pcf8591_aout}, {0} }; /* This function is called when: * pcf8591_driver is inserted (when this module is loaded), for each available adapter * when a new adapter is inserted (and pcf8591_driver is still present) */ static int pcf8591_attach_adapter(struct i2c_adapter *adapter) { return i2c_detect(adapter, &addr_data, pcf8591_detect); } /* This function is called by i2c_detect */ int pcf8591_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind) { int i; struct i2c_client *new_client; struct pcf8591_data *data; int err = 0; const char *type_name = ""; const char *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 (KERN_ERR "pcf8591.o: pcf8591_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. */ if (!(new_client = kmalloc(sizeof(struct i2c_client) + sizeof(struct pcf8591_data), GFP_KERNEL))) { err = -ENOMEM; goto ERROR0; } data = (struct pcf8591_data *) (new_client + 1); new_client->addr = address; new_client->data = data; new_client->adapter = adapter; new_client->driver = &pcf8591_driver; new_client->flags = 0; /* Now, we would do the remaining detection. But the PCF8591 is plainly impossible to detect! Stupid chip. */ /* Determine the chip type - only one kind supported! */ if (kind <= 0) kind = pcf8591; if (kind == pcf8591) { type_name = "pcf8591"; client_name = "PCF8591 chip"; } else { #ifdef DEBUG printk(KERN_ERR "pcf8591.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 = pcf8591_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, pcf8591_dir_table_template)) < 0) { err = i; goto ERROR4; } data->sysctl_id = i; /* Initialize the PCF8591 chip */ pcf8591_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; } static int pcf8591_detach_client(struct i2c_client *client) { int err; i2c_deregister_entry(((struct pcf8591_data *) (client->data))-> sysctl_id); if ((err = i2c_detach_client(client))) { printk (KERN_ERR "pcf8591.o: Client deregistration failed, client not detached.\n"); return err; } kfree(client); return 0; } /* Called when we have found a new PCF8591. */ static void pcf8591_init_client(struct i2c_client *client) { struct pcf8591_data *data = client->data; data->control_byte = PCF8591_INIT_CONTROL_BYTE; data->aout = PCF8591_INIT_AOUT; i2c_smbus_write_byte_data(client, data->control_byte, data->aout); } static void pcf8591_update_client(struct i2c_client *client) { struct pcf8591_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(KERN_DEBUG "Starting pcf8591 update\n"); #endif i2c_smbus_write_byte(client, data->control_byte); i2c_smbus_read_byte(client); /* The first byte transmitted contains the */ /* conversion code of the previous read cycled */ /* FLUSH IT ! */ /* Number of byte to read to signed depend on the analog input mode */ data->ch[0] = i2c_smbus_read_byte(client); data->ch[1] = i2c_smbus_read_byte(client); /* In all case, read at least two values */ if ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) != 0x30) data->ch[2] = i2c_smbus_read_byte(client); /* Read the third value if not in "two differential inputs" mode */ if ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 0x00) data->ch[3] = i2c_smbus_read_byte(client); /* Read the fourth value only in "four single ended inputs" mode */ data->last_updated = jiffies; data->valid = 1; } up(&data->update_lock); } /* The next few functions are the call-back functions of the /proc/sys and sysctl files. Which function is used is defined in the ctl_table in the extra1 field. */ void pcf8591_ain_conf(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct pcf8591_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { results[0] = (data->control_byte & PCF8591_CONTROL_BYTE_AIP) >> 4; *nrels_mag = 1; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { if (results[0] >= 0 && results[0] <= 3) { data->control_byte &= ~PCF8591_CONTROL_BYTE_AIP; data->control_byte |= (results[0] << 4); i2c_smbus_write_byte(client, data->control_byte); data->valid = 0; } } } } void pcf8591_ain(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct pcf8591_data *data = client->data; int nr = ctl_name - PCF8591_SYSCTL_CH0; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { pcf8591_update_client(client); /* Number of data to show and conversion to signed depend on */ /* the analog input mode */ switch(nr) { case 0: if (((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 0) | ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 2)) results[0] = data->ch[0]; /* single ended */ else results[0] = REG_TO_SIGNED(data->ch[0]);/* differential */ break; case 1: if (((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 0) | ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 2)) results[0] = data->ch[1]; /* single ended */ else results[0] = REG_TO_SIGNED(data->ch[1]);/* differential */ break; case 2: if ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 3) results[0] = 0; /* channel not used */ else if ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 0) results[0] = data->ch[2]; /* single ended */ else results[0] = REG_TO_SIGNED(data->ch[2]);/* differential */ break; case 3: if (((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 0) | ((data->control_byte & PCF8591_CONTROL_BYTE_AIP) == 2)) results[0] = data->ch[3]; /* single ended */ else results[0] = 0; /* channel not used */ break; } *nrels_mag = 1; } } void pcf8591_aout_enable(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct pcf8591_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { results[0] = !(!(data->control_byte & PCF8591_CONTROL_BYTE_AOEF)); *nrels_mag = 1; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { if (results[0]) data->control_byte |= PCF8591_CONTROL_BYTE_AOEF; else data->control_byte &= ~PCF8591_CONTROL_BYTE_AOEF; i2c_smbus_write_byte(client, data->control_byte); } } } void pcf8591_aout(struct i2c_client *client, int operation, int ctl_name, int *nrels_mag, long *results) { struct pcf8591_data *data = client->data; if (operation == SENSORS_PROC_REAL_INFO) *nrels_mag = 0; else if (operation == SENSORS_PROC_REAL_READ) { results[0] = data->aout; *nrels_mag = 1; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { if (results[0] >= 0 && results[0] <= 255) /* ignore values outside DAC range */ { data->aout = results[0]; i2c_smbus_write_byte_data(client, data->control_byte, data->aout); } } } } static int __init sm_pcf8591_init(void) { printk(KERN_INFO "pcf8591.o version %s (%s)\n", LM_VERSION, LM_DATE); return i2c_add_driver(&pcf8591_driver); } static void __exit sm_pcf8591_exit(void) { i2c_del_driver(&pcf8591_driver); } MODULE_AUTHOR("Aurelien Jarno "); MODULE_DESCRIPTION("PCF8591 driver"); MODULE_LICENSE("GPL"); module_init(sm_pcf8591_init); module_exit(sm_pcf8591_exit);