// SPDX-License-Identifier: GPL-2.0-or-later /* * 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 <jdelvare@suse.de> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/mutex.h> #include <linux/err.h> #include <linux/hwmon.h> /* Insmod parameters */ 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 device *hwmon_dev; 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 out0_output_show(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 out0_output_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { unsigned long val; struct i2c_client *client = to_i2c_client(dev); struct pcf8591_data *data = i2c_get_clientdata(client); int err; err = kstrtoul(buf, 10, &val); if (err) return err; val /= 10; if (val > 255) return -EINVAL; data->aout = val; i2c_smbus_write_byte_data(client, data->control, data->aout); return count; } static DEVICE_ATTR_RW(out0_output); static ssize_t out0_enable_show(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 out0_enable_store(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; int err; err = kstrtoul(buf, 10, &val); if (err) return err; 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_RW(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 */ static int pcf8591_probe(struct i2c_client *client) { struct pcf8591_data *data; int err; data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data), GFP_KERNEL); if (!data) return -ENOMEM; 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) return err; /* Register input2 if not in "two differential inputs" mode */ if (input_mode != 3) { err = device_create_file(&client->dev, &dev_attr_in2_input); if (err) goto exit_sysfs_remove; } /* Register input3 only in "four single ended inputs" mode */ if (input_mode == 0) { err = device_create_file(&client->dev, &dev_attr_in3_input); if (err) goto exit_sysfs_remove; } data->hwmon_dev = hwmon_device_register(&client->dev); if (IS_ERR(data->hwmon_dev)) { err = PTR_ERR(data->hwmon_dev); 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); return err; } static int pcf8591_remove(struct i2c_client *client) { struct pcf8591_data *data = i2c_get_clientdata(client); hwmon_device_unregister(data->hwmon_dev); sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); 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_new = pcf8591_probe, .remove = pcf8591_remove, .id_table = pcf8591_id, }; static int __init pcf8591_init(void) { if (input_mode < 0 || input_mode > 3) { pr_warn("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);