drivers/usb/misc/cytherm.c

   1 /* -*- linux-c -*-
   2  * Cypress USB Thermometer driver
   3  *
   4  * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com>
   5  *
   6  * This driver works with Elektor magazine USB Interface as published in
   7  * issue #291. It should also work with the original starter kit/demo board
   8  * from Cypress.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation, version 2.
  13  *
  14  */
  15
  16
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/usb.h>
  22
  23 #define DRIVER_VERSION "v1.0"
  24 #define DRIVER_AUTHOR "Erik Rigtorp"
  25 #define DRIVER_DESC "Cypress USB Thermometer driver"
  26
  27 #define USB_SKEL_VENDOR_ID      0x04b4
  28 #define USB_SKEL_PRODUCT_ID     0x0002
  29
  30 static struct usb_device_id id_table [] = {
  31         { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
  32         { }
  33 };
  34 MODULE_DEVICE_TABLE (usb, id_table);
  35
  36 /* Structure to hold all of our device specific stuff */
  37 struct usb_cytherm {
  38         struct usb_device    *udev;      /* save off the usb device pointer */
  39         struct usb_interface *interface; /* the interface for this device */
  40         int brightness;
  41 };
  42
  43
  44 /* local function prototypes */
  45 static int cytherm_probe(struct usb_interface *interface,
  46                          const struct usb_device_id *id);
  47 static void cytherm_disconnect(struct usb_interface *interface);
  48
  49
  50 /* usb specific object needed to register this driver with the usb subsystem */
  51 static struct usb_driver cytherm_driver = {
  52         .name =         "cytherm",
  53         .probe =        cytherm_probe,
  54         .disconnect =   cytherm_disconnect,
  55         .id_table =     id_table,
  56 };
  57
  58 /* Vendor requests */
  59 /* They all operate on one byte at a time */
  60 #define PING       0x00
  61 #define READ_ROM   0x01 /* Reads form ROM, value = address */
  62 #define READ_RAM   0x02 /* Reads form RAM, value = address */
  63 #define WRITE_RAM  0x03 /* Write to RAM, value = address, index = data */
  64 #define READ_PORT  0x04 /* Reads from port, value = address */
  65 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
  66
  67
  68 /* Send a vendor command to device */
  69 static int vendor_command(struct usb_device *dev, unsigned char request,
  70                           unsigned char value, unsigned char index,
  71                           void *buf, int size)
  72 {
  73         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
  74                                request,
  75                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  76                                value,
  77                                index, buf, size,
  78                                USB_CTRL_GET_TIMEOUT);
  79 }
  80
  81
  82
  83 #define BRIGHTNESS 0x2c     /* RAM location for brightness value */
  84 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
  85
  86 static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf)
  87 {
  88         struct usb_interface *intf = to_usb_interface(dev);
  89         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
  90
  91         return sprintf(buf, "%i", cytherm->brightness);
  92 }
  93
  94 static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf,
  95                               size_t count)
  96 {
  97         struct usb_interface *intf = to_usb_interface(dev);
  98         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
  99
 100         unsigned char *buffer;
 101         int retval;
 102
 103         buffer = kmalloc(8, GFP_KERNEL);
 104         if (!buffer) {
 105                 dev_err(&cytherm->udev->dev, "out of memory\n");
 106                 return 0;
 107         }
 108
 109         cytherm->brightness = simple_strtoul(buf, NULL, 10);
 110
 111         if (cytherm->brightness > 0xFF)
 112                 cytherm->brightness = 0xFF;
 113         else if (cytherm->brightness < 0)
 114                 cytherm->brightness = 0;
 115
 116         /* Set brightness */
 117         retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
 118                                 cytherm->brightness, buffer, 8);
 119         if (retval)
 120                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 121         /* Inform µC that we have changed the brightness setting */
 122         retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
 123                                 0x01, buffer, 8);
 124         if (retval)
 125                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 126
 127         kfree(buffer);
 128
 129         return count;
 130 }
 131
 132 static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP,
 133                    show_brightness, set_brightness);
 134
 135
 136 #define TEMP 0x33 /* RAM location for temperature */
 137 #define SIGN 0x34 /* RAM location for temperature sign */
 138
 139 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf)
 140 {
 141
 142         struct usb_interface *intf = to_usb_interface(dev);
 143         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 144
 145         int retval;
 146         unsigned char *buffer;
 147
 148         int temp, sign;
 149
 150         buffer = kmalloc(8, GFP_KERNEL);
 151         if (!buffer) {
 152                 dev_err(&cytherm->udev->dev, "out of memory\n");
 153                 return 0;
 154         }
 155
 156         /* read temperature */
 157         retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
 158         if (retval)
 159                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 160         temp = buffer[1];
 161
 162         /* read sign */
 163         retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
 164         if (retval)
 165                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 166         sign = buffer[1];
 167
 168         kfree(buffer);
 169
 170         return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
 171                        5*(temp - ((temp >> 1) << 1)));
 172 }
 173
 174
 175 static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 176 {
 177         return count;
 178 }
 179
 180 static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp);
 181
 182
 183 #define BUTTON 0x7a
 184
 185 static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf)
 186 {
 187
 188         struct usb_interface *intf = to_usb_interface(dev);
 189         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 190
 191         int retval;
 192         unsigned char *buffer;
 193
 194         buffer = kmalloc(8, GFP_KERNEL);
 195         if (!buffer) {
 196                 dev_err(&cytherm->udev->dev, "out of memory\n");
 197                 return 0;
 198         }
 199
 200         /* check button */
 201         retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
 202         if (retval)
 203                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 204
 205         retval = buffer[1];
 206
 207         kfree(buffer);
 208
 209         if (retval)
 210                 return sprintf(buf, "1");
 211         else
 212                 return sprintf(buf, "0");
 213 }
 214
 215
 216 static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 217 {
 218         return count;
 219 }
 220
 221 static DEVICE_ATTR(button, S_IRUGO, show_button, set_button);
 222
 223
 224 static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf)
 225 {
 226         struct usb_interface *intf = to_usb_interface(dev);
 227         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 228
 229         int retval;
 230         unsigned char *buffer;
 231
 232         buffer = kmalloc(8, GFP_KERNEL);
 233         if (!buffer) {
 234                 dev_err(&cytherm->udev->dev, "out of memory\n");
 235                 return 0;
 236         }
 237
 238         retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
 239         if (retval)
 240                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 241
 242         retval = buffer[1];
 243
 244         kfree(buffer);
 245
 246         return sprintf(buf, "%d", retval);
 247 }
 248
 249
 250 static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 251 {
 252         struct usb_interface *intf = to_usb_interface(dev);
 253         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 254
 255         unsigned char *buffer;
 256         int retval;
 257         int tmp;
 258
 259         buffer = kmalloc(8, GFP_KERNEL);
 260         if (!buffer) {
 261                 dev_err(&cytherm->udev->dev, "out of memory\n");
 262                 return 0;
 263         }
 264
 265         tmp = simple_strtoul(buf, NULL, 10);
 266
 267         if (tmp > 0xFF)
 268                 tmp = 0xFF;
 269         else if (tmp < 0)
 270                 tmp = 0;
 271
 272         retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
 273                                 tmp, buffer, 8);
 274         if (retval)
 275                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 276
 277         kfree(buffer);
 278
 279         return count;
 280 }
 281
 282 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0);
 283
 284 static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf)
 285 {
 286         struct usb_interface *intf = to_usb_interface(dev);
 287         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 288
 289         int retval;
 290         unsigned char *buffer;
 291
 292         buffer = kmalloc(8, GFP_KERNEL);
 293         if (!buffer) {
 294                 dev_err(&cytherm->udev->dev, "out of memory\n");
 295                 return 0;
 296         }
 297
 298         retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
 299         if (retval)
 300                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 301
 302         retval = buffer[1];
 303
 304         kfree(buffer);
 305
 306         return sprintf(buf, "%d", retval);
 307 }
 308
 309
 310 static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 311 {
 312         struct usb_interface *intf = to_usb_interface(dev);
 313         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 314
 315         unsigned char *buffer;
 316         int retval;
 317         int tmp;
 318
 319         buffer = kmalloc(8, GFP_KERNEL);
 320         if (!buffer) {
 321                 dev_err(&cytherm->udev->dev, "out of memory\n");
 322                 return 0;
 323         }
 324
 325         tmp = simple_strtoul(buf, NULL, 10);
 326
 327         if (tmp > 0xFF)
 328                 tmp = 0xFF;
 329         else if (tmp < 0)
 330                 tmp = 0;
 331
 332         retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
 333                                 tmp, buffer, 8);
 334         if (retval)
 335                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 336
 337         kfree(buffer);
 338
 339         return count;
 340 }
 341
 342 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1);
 343
 344
 345
 346 static int cytherm_probe(struct usb_interface *interface,
 347                          const struct usb_device_id *id)
 348 {
 349         struct usb_device *udev = interface_to_usbdev(interface);
 350         struct usb_cytherm *dev = NULL;
 351         int retval = -ENOMEM;
 352
 353         dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
 354         if (dev == NULL) {
 355                 dev_err (&interface->dev, "Out of memory\n");
 356                 goto error_mem;
 357         }
 358
 359         dev->udev = usb_get_dev(udev);
 360
 361         usb_set_intfdata (interface, dev);
 362
 363         dev->brightness = 0xFF;
 364
 365         retval = device_create_file(&interface->dev, &dev_attr_brightness);
 366         if (retval)
 367                 goto error;
 368         retval = device_create_file(&interface->dev, &dev_attr_temp);
 369         if (retval)
 370                 goto error;
 371         retval = device_create_file(&interface->dev, &dev_attr_button);
 372         if (retval)
 373                 goto error;
 374         retval = device_create_file(&interface->dev, &dev_attr_port0);
 375         if (retval)
 376                 goto error;
 377         retval = device_create_file(&interface->dev, &dev_attr_port1);
 378         if (retval)
 379                 goto error;
 380
 381         dev_info (&interface->dev,
 382                   "Cypress thermometer device now attached\n");
 383         return 0;
 384 error:
 385         device_remove_file(&interface->dev, &dev_attr_brightness);
 386         device_remove_file(&interface->dev, &dev_attr_temp);
 387         device_remove_file(&interface->dev, &dev_attr_button);
 388         device_remove_file(&interface->dev, &dev_attr_port0);
 389         device_remove_file(&interface->dev, &dev_attr_port1);
 390         usb_set_intfdata (interface, NULL);
 391         usb_put_dev(dev->udev);
 392         kfree(dev);
 393 error_mem:
 394         return retval;
 395 }
 396
 397 static void cytherm_disconnect(struct usb_interface *interface)
 398 {
 399         struct usb_cytherm *dev;
 400
 401         dev = usb_get_intfdata (interface);
 402
 403         device_remove_file(&interface->dev, &dev_attr_brightness);
 404         device_remove_file(&interface->dev, &dev_attr_temp);
 405         device_remove_file(&interface->dev, &dev_attr_button);
 406         device_remove_file(&interface->dev, &dev_attr_port0);
 407         device_remove_file(&interface->dev, &dev_attr_port1);
 408
 409         /* first remove the files, then NULL the pointer */
 410         usb_set_intfdata (interface, NULL);
 411
 412         usb_put_dev(dev->udev);
 413
 414         kfree(dev);
 415
 416         dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
 417 }
 418
 419
 420 static int __init usb_cytherm_init(void)
 421 {
 422         int result;
 423
 424         result = usb_register(&cytherm_driver);
 425         if (result)
 426         {
 427                 err("usb_register failed. Error number %d", result);
 428                 return result;
 429         }
 430
 431         info(DRIVER_VERSION ":" DRIVER_DESC);
 432         return 0;
 433 }
 434
 435 static void __exit usb_cytherm_exit(void)
 436 {
 437         usb_deregister(&cytherm_driver);
 438 }
 439
 440
 441 module_init (usb_cytherm_init);
 442 module_exit (usb_cytherm_exit);
 443
 444 MODULE_AUTHOR(DRIVER_AUTHOR);
 445 MODULE_DESCRIPTION(DRIVER_DESC);
 446 MODULE_LICENSE("GPL");