1 /* 2 * Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net> 3 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 4 * the help of Jean Delvare <jdelvare@suse.de> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/slab.h> 26 #include <linux/i2c.h> 27 #include <linux/mutex.h> 28 #include <linux/err.h> 29 #include <linux/hwmon.h> 30 31 /* Insmod parameters */ 32 33 static int input_mode; 34 module_param(input_mode, int, 0); 35 MODULE_PARM_DESC(input_mode, 36 "Analog input mode:\n" 37 " 0 = four single ended inputs\n" 38 " 1 = three differential inputs\n" 39 " 2 = single ended and differential mixed\n" 40 " 3 = two differential inputs\n"); 41 42 /* 43 * The PCF8591 control byte 44 * 7 6 5 4 3 2 1 0 45 * | 0 |AOEF| AIP | 0 |AINC| AICH | 46 */ 47 48 /* Analog Output Enable Flag (analog output active if 1) */ 49 #define PCF8591_CONTROL_AOEF 0x40 50 51 /* 52 * Analog Input Programming 53 * 0x00 = four single ended inputs 54 * 0x10 = three differential inputs 55 * 0x20 = single ended and differential mixed 56 * 0x30 = two differential inputs 57 */ 58 #define PCF8591_CONTROL_AIP_MASK 0x30 59 60 /* Autoincrement Flag (switch on if 1) */ 61 #define PCF8591_CONTROL_AINC 0x04 62 63 /* 64 * Channel selection 65 * 0x00 = channel 0 66 * 0x01 = channel 1 67 * 0x02 = channel 2 68 * 0x03 = channel 3 69 */ 70 #define PCF8591_CONTROL_AICH_MASK 0x03 71 72 /* Initial values */ 73 #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF) 74 #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */ 75 76 /* Conversions */ 77 #define REG_TO_SIGNED(reg) (((reg) & 0x80) ? ((reg) - 256) : (reg)) 78 79 struct pcf8591_data { 80 struct device *hwmon_dev; 81 struct mutex update_lock; 82 83 u8 control; 84 u8 aout; 85 }; 86 87 static void pcf8591_init_client(struct i2c_client *client); 88 static int pcf8591_read_channel(struct device *dev, int channel); 89 90 /* following are the sysfs callback functions */ 91 #define show_in_channel(channel) \ 92 static ssize_t show_in##channel##_input(struct device *dev, \ 93 struct device_attribute *attr, \ 94 char *buf) \ 95 { \ 96 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\ 97 } \ 98 static DEVICE_ATTR(in##channel##_input, S_IRUGO, \ 99 show_in##channel##_input, NULL); 100 101 show_in_channel(0); 102 show_in_channel(1); 103 show_in_channel(2); 104 show_in_channel(3); 105 106 static ssize_t show_out0_ouput(struct device *dev, 107 struct device_attribute *attr, char *buf) 108 { 109 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); 110 return sprintf(buf, "%d\n", data->aout * 10); 111 } 112 113 static ssize_t set_out0_output(struct device *dev, 114 struct device_attribute *attr, 115 const char *buf, size_t count) 116 { 117 unsigned long val; 118 struct i2c_client *client = to_i2c_client(dev); 119 struct pcf8591_data *data = i2c_get_clientdata(client); 120 int err; 121 122 err = kstrtoul(buf, 10, &val); 123 if (err) 124 return err; 125 126 val /= 10; 127 if (val > 255) 128 return -EINVAL; 129 130 data->aout = val; 131 i2c_smbus_write_byte_data(client, data->control, data->aout); 132 return count; 133 } 134 135 static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO, 136 show_out0_ouput, set_out0_output); 137 138 static ssize_t show_out0_enable(struct device *dev, 139 struct device_attribute *attr, char *buf) 140 { 141 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); 142 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF))); 143 } 144 145 static ssize_t set_out0_enable(struct device *dev, 146 struct device_attribute *attr, 147 const char *buf, size_t count) 148 { 149 struct i2c_client *client = to_i2c_client(dev); 150 struct pcf8591_data *data = i2c_get_clientdata(client); 151 unsigned long val; 152 int err; 153 154 err = kstrtoul(buf, 10, &val); 155 if (err) 156 return err; 157 158 mutex_lock(&data->update_lock); 159 if (val) 160 data->control |= PCF8591_CONTROL_AOEF; 161 else 162 data->control &= ~PCF8591_CONTROL_AOEF; 163 i2c_smbus_write_byte(client, data->control); 164 mutex_unlock(&data->update_lock); 165 return count; 166 } 167 168 static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, 169 show_out0_enable, set_out0_enable); 170 171 static struct attribute *pcf8591_attributes[] = { 172 &dev_attr_out0_enable.attr, 173 &dev_attr_out0_output.attr, 174 &dev_attr_in0_input.attr, 175 &dev_attr_in1_input.attr, 176 NULL 177 }; 178 179 static const struct attribute_group pcf8591_attr_group = { 180 .attrs = pcf8591_attributes, 181 }; 182 183 static struct attribute *pcf8591_attributes_opt[] = { 184 &dev_attr_in2_input.attr, 185 &dev_attr_in3_input.attr, 186 NULL 187 }; 188 189 static const struct attribute_group pcf8591_attr_group_opt = { 190 .attrs = pcf8591_attributes_opt, 191 }; 192 193 /* 194 * Real code 195 */ 196 197 static int pcf8591_probe(struct i2c_client *client, 198 const struct i2c_device_id *id) 199 { 200 struct pcf8591_data *data; 201 int err; 202 203 data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data), 204 GFP_KERNEL); 205 if (!data) 206 return -ENOMEM; 207 208 i2c_set_clientdata(client, data); 209 mutex_init(&data->update_lock); 210 211 /* Initialize the PCF8591 chip */ 212 pcf8591_init_client(client); 213 214 /* Register sysfs hooks */ 215 err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group); 216 if (err) 217 return err; 218 219 /* Register input2 if not in "two differential inputs" mode */ 220 if (input_mode != 3) { 221 err = device_create_file(&client->dev, &dev_attr_in2_input); 222 if (err) 223 goto exit_sysfs_remove; 224 } 225 226 /* Register input3 only in "four single ended inputs" mode */ 227 if (input_mode == 0) { 228 err = device_create_file(&client->dev, &dev_attr_in3_input); 229 if (err) 230 goto exit_sysfs_remove; 231 } 232 233 data->hwmon_dev = hwmon_device_register(&client->dev); 234 if (IS_ERR(data->hwmon_dev)) { 235 err = PTR_ERR(data->hwmon_dev); 236 goto exit_sysfs_remove; 237 } 238 239 return 0; 240 241 exit_sysfs_remove: 242 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); 243 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); 244 return err; 245 } 246 247 static int pcf8591_remove(struct i2c_client *client) 248 { 249 struct pcf8591_data *data = i2c_get_clientdata(client); 250 251 hwmon_device_unregister(data->hwmon_dev); 252 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); 253 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); 254 return 0; 255 } 256 257 /* Called when we have found a new PCF8591. */ 258 static void pcf8591_init_client(struct i2c_client *client) 259 { 260 struct pcf8591_data *data = i2c_get_clientdata(client); 261 data->control = PCF8591_INIT_CONTROL; 262 data->aout = PCF8591_INIT_AOUT; 263 264 i2c_smbus_write_byte_data(client, data->control, data->aout); 265 266 /* 267 * The first byte transmitted contains the conversion code of the 268 * previous read cycle. FLUSH IT! 269 */ 270 i2c_smbus_read_byte(client); 271 } 272 273 static int pcf8591_read_channel(struct device *dev, int channel) 274 { 275 u8 value; 276 struct i2c_client *client = to_i2c_client(dev); 277 struct pcf8591_data *data = i2c_get_clientdata(client); 278 279 mutex_lock(&data->update_lock); 280 281 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) { 282 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK) 283 | channel; 284 i2c_smbus_write_byte(client, data->control); 285 286 /* 287 * The first byte transmitted contains the conversion code of 288 * the previous read cycle. FLUSH IT! 289 */ 290 i2c_smbus_read_byte(client); 291 } 292 value = i2c_smbus_read_byte(client); 293 294 mutex_unlock(&data->update_lock); 295 296 if ((channel == 2 && input_mode == 2) || 297 (channel != 3 && (input_mode == 1 || input_mode == 3))) 298 return 10 * REG_TO_SIGNED(value); 299 else 300 return 10 * value; 301 } 302 303 static const struct i2c_device_id pcf8591_id[] = { 304 { "pcf8591", 0 }, 305 { } 306 }; 307 MODULE_DEVICE_TABLE(i2c, pcf8591_id); 308 309 static struct i2c_driver pcf8591_driver = { 310 .driver = { 311 .name = "pcf8591", 312 }, 313 .probe = pcf8591_probe, 314 .remove = pcf8591_remove, 315 .id_table = pcf8591_id, 316 }; 317 318 static int __init pcf8591_init(void) 319 { 320 if (input_mode < 0 || input_mode > 3) { 321 pr_warn("invalid input_mode (%d)\n", input_mode); 322 input_mode = 0; 323 } 324 return i2c_add_driver(&pcf8591_driver); 325 } 326 327 static void __exit pcf8591_exit(void) 328 { 329 i2c_del_driver(&pcf8591_driver); 330 } 331 332 MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); 333 MODULE_DESCRIPTION("PCF8591 driver"); 334 MODULE_LICENSE("GPL"); 335 336 module_init(pcf8591_init); 337 module_exit(pcf8591_exit); 338