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