linux/drivers/usb/misc/cytherm.c
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   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/slab.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
  30static const struct usb_device_id id_table[] = {
  31        { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
  32        { }
  33};
  34MODULE_DEVICE_TABLE (usb, id_table);
  35
  36/* Structure to hold all of our device specific stuff */
  37struct 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 */
  45static int cytherm_probe(struct usb_interface *interface, 
  46                         const struct usb_device_id *id);
  47static void cytherm_disconnect(struct usb_interface *interface);
  48
  49
  50/* usb specific object needed to register this driver with the usb subsystem */
  51static 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 */
  69static 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
  86static 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
  94static 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
 132static 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
 139static 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
 175static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 176{
 177        return count;
 178}
 179
 180static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp);
 181
 182
 183#define BUTTON 0x7a
 184
 185static 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
 216static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 217{
 218        return count;
 219}
 220
 221static DEVICE_ATTR(button, S_IRUGO, show_button, set_button);
 222
 223
 224static 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
 250static 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
 282static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0);
 283
 284static 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
 310static 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
 342static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1);
 343
 344
 345
 346static 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;
 384error:
 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);
 393error_mem:
 394        return retval;
 395}
 396
 397static 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
 419module_usb_driver(cytherm_driver);
 420
 421MODULE_AUTHOR(DRIVER_AUTHOR);
 422MODULE_DESCRIPTION(DRIVER_DESC);
 423MODULE_LICENSE("GPL");
 424