| /* |
| 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, |
| 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_list = normal_i2c, |
| }; |
| |
| 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); |