/* Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net> 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/i2c.h> #include <linux/mutex.h> /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; /* Insmod parameters */ I2C_CLIENT_INSMOD_1(pcf8591); static int input_mode; module_param(input_mode, int, 0); MODULE_PARM_DESC(input_mode, "Analog input mode:\n" " 0 = four single ended inputs\n" " 1 = three differential inputs\n" " 2 = single ended and differential mixed\n" " 3 = two differential inputs\n"); /* The PCF8591 control byte 7 6 5 4 3 2 1 0 | 0 |AOEF| AIP | 0 |AINC| AICH | */ /* Analog Output Enable Flag (analog output active if 1) */ #define PCF8591_CONTROL_AOEF 0x40 /* 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_AIP_MASK 0x30 /* Autoincrement Flag (switch on if 1) */ #define PCF8591_CONTROL_AINC 0x04 /* Channel selection 0x00 = channel 0 0x01 = channel 1 0x02 = channel 2 0x03 = channel 3 */ #define PCF8591_CONTROL_AICH_MASK 0x03 /* Initial values */ #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF) #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */ /* Conversions */ #define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg)) struct pcf8591_data { struct mutex update_lock; u8 control; u8 aout; }; static void pcf8591_init_client(struct i2c_client *client); static int pcf8591_read_channel(struct device *dev, int channel); /* following are the sysfs callback functions */ #define show_in_channel(channel) \ static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \ { \ return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\ } \ static DEVICE_ATTR(in##channel##_input, S_IRUGO, \ show_in##channel##_input, NULL); show_in_channel(0); show_in_channel(1); show_in_channel(2); show_in_channel(3); static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf) { struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); return sprintf(buf, "%d\n", data->aout * 10); } static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { unsigned int value; struct i2c_client *client = to_i2c_client(dev); struct pcf8591_data *data = i2c_get_clientdata(client); if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) { data->aout = value; i2c_smbus_write_byte_data(client, data->control, data->aout); return count; } return -EINVAL; } static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO, show_out0_ouput, set_out0_output); static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf) { struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF))); } static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct pcf8591_data *data = i2c_get_clientdata(client); unsigned long val = simple_strtoul(buf, NULL, 10); mutex_lock(&data->update_lock); if (val) data->control |= PCF8591_CONTROL_AOEF; else data->control &= ~PCF8591_CONTROL_AOEF; i2c_smbus_write_byte(client, data->control); mutex_unlock(&data->update_lock); return count; } static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, show_out0_enable, set_out0_enable); static struct attribute *pcf8591_attributes[] = { &dev_attr_out0_enable.attr, &dev_attr_out0_output.attr, &dev_attr_in0_input.attr, &dev_attr_in1_input.attr, NULL }; static const struct attribute_group pcf8591_attr_group = { .attrs = pcf8591_attributes, }; static struct attribute *pcf8591_attributes_opt[] = { &dev_attr_in2_input.attr, &dev_attr_in3_input.attr, NULL }; static const struct attribute_group pcf8591_attr_group_opt = { .attrs = pcf8591_attributes_opt, }; /* * Real code */ /* Return 0 if detection is successful, -ENODEV otherwise */ static int pcf8591_detect(struct i2c_client *client, int kind, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) return -ENODEV; /* Now, we would do the remaining detection. But the PCF8591 is plainly impossible to detect! Stupid chip. */ strlcpy(info->type, "pcf8591", I2C_NAME_SIZE); return 0; } static int pcf8591_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pcf8591_data *data; int err; if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) { err = -ENOMEM; goto exit; } i2c_set_clientdata(client, data); mutex_init(&data->update_lock); /* Initialize the PCF8591 chip */ pcf8591_init_client(client); /* Register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group); if (err) goto exit_kfree; /* Register input2 if not in "two differential inputs" mode */ if (input_mode != 3) { if ((err = device_create_file(&client->dev, &dev_attr_in2_input))) goto exit_sysfs_remove; } /* Register input3 only in "four single ended inputs" mode */ if (input_mode == 0) { if ((err = device_create_file(&client->dev, &dev_attr_in3_input))) goto exit_sysfs_remove; } return 0; exit_sysfs_remove: sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); exit_kfree: kfree(data); exit: return err; } static int pcf8591_remove(struct i2c_client *client) { sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); kfree(i2c_get_clientdata(client)); return 0; } /* Called when we have found a new PCF8591. */ static void pcf8591_init_client(struct i2c_client *client) { struct pcf8591_data *data = i2c_get_clientdata(client); data->control = PCF8591_INIT_CONTROL; data->aout = PCF8591_INIT_AOUT; i2c_smbus_write_byte_data(client, data->control, data->aout); /* The first byte transmitted contains the conversion code of the previous read cycle. FLUSH IT! */ i2c_smbus_read_byte(client); } static int pcf8591_read_channel(struct device *dev, int channel) { u8 value; struct i2c_client *client = to_i2c_client(dev); struct pcf8591_data *data = i2c_get_clientdata(client); mutex_lock(&data->update_lock); if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) { data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK) | channel; i2c_smbus_write_byte(client, data->control); /* The first byte transmitted contains the conversion code of the previous read cycle. FLUSH IT! */ i2c_smbus_read_byte(client); } value = i2c_smbus_read_byte(client); mutex_unlock(&data->update_lock); if ((channel == 2 && input_mode == 2) || (channel != 3 && (input_mode == 1 || input_mode == 3))) return (10 * REG_TO_SIGNED(value)); else return (10 * value); } static const struct i2c_device_id pcf8591_id[] = { { "pcf8591", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf8591_id); static struct i2c_driver pcf8591_driver = { .driver = { .name = "pcf8591", }, .probe = pcf8591_probe, .remove = pcf8591_remove, .id_table = pcf8591_id, .class = I2C_CLASS_HWMON, /* Nearest choice */ .detect = pcf8591_detect, .address_data = &addr_data, }; static int __init pcf8591_init(void) { if (input_mode < 0 || input_mode > 3) { printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n", input_mode); input_mode = 0; } return i2c_add_driver(&pcf8591_driver); } static void __exit pcf8591_exit(void) { i2c_del_driver(&pcf8591_driver); } MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); MODULE_DESCRIPTION("PCF8591 driver"); MODULE_LICENSE("GPL"); module_init(pcf8591_init); module_exit(pcf8591_exit);