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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>4 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with5 * the help of Jean Delvare <jdelvare@suse.de>6 */7 8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt9 10#include <linux/module.h>11#include <linux/init.h>12#include <linux/slab.h>13#include <linux/i2c.h>14#include <linux/mutex.h>15#include <linux/err.h>16#include <linux/hwmon.h>17#include <linux/kstrtox.h>18 19/* Insmod parameters */20 21static int input_mode;22module_param(input_mode, int, 0);23MODULE_PARM_DESC(input_mode,24 "Analog input mode:\n"25 " 0 = four single ended inputs\n"26 " 1 = three differential inputs\n"27 " 2 = single ended and differential mixed\n"28 " 3 = two differential inputs\n");29 30/*31 * The PCF8591 control byte32 * 7 6 5 4 3 2 1 033 * | 0 |AOEF| AIP | 0 |AINC| AICH |34 */35 36/* Analog Output Enable Flag (analog output active if 1) */37#define PCF8591_CONTROL_AOEF 0x4038 39/*40 * Analog Input Programming41 * 0x00 = four single ended inputs42 * 0x10 = three differential inputs43 * 0x20 = single ended and differential mixed44 * 0x30 = two differential inputs45 */46#define PCF8591_CONTROL_AIP_MASK 0x3047 48/* Autoincrement Flag (switch on if 1) */49#define PCF8591_CONTROL_AINC 0x0450 51/*52 * Channel selection53 * 0x00 = channel 054 * 0x01 = channel 155 * 0x02 = channel 256 * 0x03 = channel 357 */58#define PCF8591_CONTROL_AICH_MASK 0x0359 60/* Initial values */61#define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)62#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */63 64/* Conversions */65#define REG_TO_SIGNED(reg) (((reg) & 0x80) ? ((reg) - 256) : (reg))66 67struct pcf8591_data {68 struct device *hwmon_dev;69 struct mutex update_lock;70 71 u8 control;72 u8 aout;73};74 75static void pcf8591_init_client(struct i2c_client *client);76static int pcf8591_read_channel(struct device *dev, int channel);77 78/* following are the sysfs callback functions */79#define show_in_channel(channel) \80static ssize_t show_in##channel##_input(struct device *dev, \81 struct device_attribute *attr, \82 char *buf) \83{ \84 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\85} \86static DEVICE_ATTR(in##channel##_input, S_IRUGO, \87 show_in##channel##_input, NULL);88 89show_in_channel(0);90show_in_channel(1);91show_in_channel(2);92show_in_channel(3);93 94static ssize_t out0_output_show(struct device *dev,95 struct device_attribute *attr, char *buf)96{97 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));98 return sprintf(buf, "%d\n", data->aout * 10);99}100 101static ssize_t out0_output_store(struct device *dev,102 struct device_attribute *attr,103 const char *buf, size_t count)104{105 unsigned long val;106 struct i2c_client *client = to_i2c_client(dev);107 struct pcf8591_data *data = i2c_get_clientdata(client);108 int err;109 110 err = kstrtoul(buf, 10, &val);111 if (err)112 return err;113 114 val /= 10;115 if (val > 255)116 return -EINVAL;117 118 data->aout = val;119 i2c_smbus_write_byte_data(client, data->control, data->aout);120 return count;121}122 123static DEVICE_ATTR_RW(out0_output);124 125static ssize_t out0_enable_show(struct device *dev,126 struct device_attribute *attr, char *buf)127{128 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));129 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));130}131 132static ssize_t out0_enable_store(struct device *dev,133 struct device_attribute *attr,134 const char *buf, size_t count)135{136 struct i2c_client *client = to_i2c_client(dev);137 struct pcf8591_data *data = i2c_get_clientdata(client);138 unsigned long val;139 int err;140 141 err = kstrtoul(buf, 10, &val);142 if (err)143 return err;144 145 mutex_lock(&data->update_lock);146 if (val)147 data->control |= PCF8591_CONTROL_AOEF;148 else149 data->control &= ~PCF8591_CONTROL_AOEF;150 i2c_smbus_write_byte(client, data->control);151 mutex_unlock(&data->update_lock);152 return count;153}154 155static DEVICE_ATTR_RW(out0_enable);156 157static struct attribute *pcf8591_attributes[] = {158 &dev_attr_out0_enable.attr,159 &dev_attr_out0_output.attr,160 &dev_attr_in0_input.attr,161 &dev_attr_in1_input.attr,162 NULL163};164 165static const struct attribute_group pcf8591_attr_group = {166 .attrs = pcf8591_attributes,167};168 169static struct attribute *pcf8591_attributes_opt[] = {170 &dev_attr_in2_input.attr,171 &dev_attr_in3_input.attr,172 NULL173};174 175static const struct attribute_group pcf8591_attr_group_opt = {176 .attrs = pcf8591_attributes_opt,177};178 179/*180 * Real code181 */182 183static int pcf8591_probe(struct i2c_client *client)184{185 struct pcf8591_data *data;186 int err;187 188 data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data),189 GFP_KERNEL);190 if (!data)191 return -ENOMEM;192 193 i2c_set_clientdata(client, data);194 mutex_init(&data->update_lock);195 196 /* Initialize the PCF8591 chip */197 pcf8591_init_client(client);198 199 /* Register sysfs hooks */200 err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);201 if (err)202 return err;203 204 /* Register input2 if not in "two differential inputs" mode */205 if (input_mode != 3) {206 err = device_create_file(&client->dev, &dev_attr_in2_input);207 if (err)208 goto exit_sysfs_remove;209 }210 211 /* Register input3 only in "four single ended inputs" mode */212 if (input_mode == 0) {213 err = device_create_file(&client->dev, &dev_attr_in3_input);214 if (err)215 goto exit_sysfs_remove;216 }217 218 data->hwmon_dev = hwmon_device_register(&client->dev);219 if (IS_ERR(data->hwmon_dev)) {220 err = PTR_ERR(data->hwmon_dev);221 goto exit_sysfs_remove;222 }223 224 return 0;225 226exit_sysfs_remove:227 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);228 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);229 return err;230}231 232static void pcf8591_remove(struct i2c_client *client)233{234 struct pcf8591_data *data = i2c_get_clientdata(client);235 236 hwmon_device_unregister(data->hwmon_dev);237 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);238 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);239}240 241/* Called when we have found a new PCF8591. */242static void pcf8591_init_client(struct i2c_client *client)243{244 struct pcf8591_data *data = i2c_get_clientdata(client);245 data->control = PCF8591_INIT_CONTROL;246 data->aout = PCF8591_INIT_AOUT;247 248 i2c_smbus_write_byte_data(client, data->control, data->aout);249 250 /*251 * The first byte transmitted contains the conversion code of the252 * previous read cycle. FLUSH IT!253 */254 i2c_smbus_read_byte(client);255}256 257static int pcf8591_read_channel(struct device *dev, int channel)258{259 u8 value;260 struct i2c_client *client = to_i2c_client(dev);261 struct pcf8591_data *data = i2c_get_clientdata(client);262 263 mutex_lock(&data->update_lock);264 265 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {266 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)267 | channel;268 i2c_smbus_write_byte(client, data->control);269 270 /*271 * The first byte transmitted contains the conversion code of272 * the previous read cycle. FLUSH IT!273 */274 i2c_smbus_read_byte(client);275 }276 value = i2c_smbus_read_byte(client);277 278 mutex_unlock(&data->update_lock);279 280 if ((channel == 2 && input_mode == 2) ||281 (channel != 3 && (input_mode == 1 || input_mode == 3)))282 return 10 * REG_TO_SIGNED(value);283 else284 return 10 * value;285}286 287static const struct i2c_device_id pcf8591_id[] = {288 { "pcf8591" },289 { }290};291MODULE_DEVICE_TABLE(i2c, pcf8591_id);292 293static struct i2c_driver pcf8591_driver = {294 .driver = {295 .name = "pcf8591",296 },297 .probe = pcf8591_probe,298 .remove = pcf8591_remove,299 .id_table = pcf8591_id,300};301 302static int __init pcf8591_init(void)303{304 if (input_mode < 0 || input_mode > 3) {305 pr_warn("invalid input_mode (%d)\n", input_mode);306 input_mode = 0;307 }308 return i2c_add_driver(&pcf8591_driver);309}310 311static void __exit pcf8591_exit(void)312{313 i2c_del_driver(&pcf8591_driver);314}315 316MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");317MODULE_DESCRIPTION("PCF8591 driver");318MODULE_LICENSE("GPL");319 320module_init(pcf8591_init);321module_exit(pcf8591_exit);322