linux/drivers/usb/misc/cytherm.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* -*- linux-c -*-
   3 * Cypress USB Thermometer driver 
   4 * 
   5 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com>
   6 * 
   7 * This driver works with Elektor magazine USB Interface as published in 
   8 * issue #291. It should also work with the original starter kit/demo board
   9 * from Cypress.
  10 */
  11
  12
  13#include <linux/kernel.h>
  14#include <linux/errno.h>
  15#include <linux/slab.h>
  16#include <linux/module.h>
  17#include <linux/usb.h>
  18
  19#define DRIVER_AUTHOR "Erik Rigtorp"
  20#define DRIVER_DESC "Cypress USB Thermometer driver"
  21
  22#define USB_SKEL_VENDOR_ID      0x04b4
  23#define USB_SKEL_PRODUCT_ID     0x0002
  24
  25static const struct usb_device_id id_table[] = {
  26        { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
  27        { }
  28};
  29MODULE_DEVICE_TABLE (usb, id_table);
  30
  31/* Structure to hold all of our device specific stuff */
  32struct usb_cytherm {
  33        struct usb_device    *udev;      /* save off the usb device pointer */
  34        struct usb_interface *interface; /* the interface for this device */
  35        int brightness;
  36};
  37
  38
  39/* Vendor requests */
  40/* They all operate on one byte at a time */
  41#define PING       0x00
  42#define READ_ROM   0x01 /* Reads form ROM, value = address */
  43#define READ_RAM   0x02 /* Reads form RAM, value = address */
  44#define WRITE_RAM  0x03 /* Write to RAM, value = address, index = data */
  45#define READ_PORT  0x04 /* Reads from port, value = address */
  46#define WRITE_PORT 0x05 /* Write to port, value = address, index = data */ 
  47
  48
  49/* Send a vendor command to device */
  50static int vendor_command(struct usb_device *dev, unsigned char request, 
  51                          unsigned char value, unsigned char index,
  52                          void *buf, int size)
  53{
  54        return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
  55                               request, 
  56                               USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  57                               value, 
  58                               index, buf, size,
  59                               USB_CTRL_GET_TIMEOUT);
  60}
  61
  62
  63
  64#define BRIGHTNESS 0x2c     /* RAM location for brightness value */
  65#define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
  66
  67static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf)
  68{
  69        struct usb_interface *intf = to_usb_interface(dev);    
  70        struct usb_cytherm *cytherm = usb_get_intfdata(intf);     
  71
  72        return sprintf(buf, "%i", cytherm->brightness);
  73}
  74
  75static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf,
  76                              size_t count)
  77{
  78        struct usb_interface *intf = to_usb_interface(dev);
  79        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
  80
  81        unsigned char *buffer;
  82        int retval;
  83   
  84        buffer = kmalloc(8, GFP_KERNEL);
  85        if (!buffer)
  86                return 0;
  87
  88        cytherm->brightness = simple_strtoul(buf, NULL, 10);
  89   
  90        if (cytherm->brightness > 0xFF)
  91                cytherm->brightness = 0xFF;
  92        else if (cytherm->brightness < 0)
  93                cytherm->brightness = 0;
  94   
  95        /* Set brightness */
  96        retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 
  97                                cytherm->brightness, buffer, 8);
  98        if (retval)
  99                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 100        /* Inform \xC2\xB5C that we have changed the brightness setting */
 101        retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
 102                                0x01, buffer, 8);
 103        if (retval)
 104                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 105   
 106        kfree(buffer);
 107   
 108        return count;
 109}
 110static DEVICE_ATTR_RW(brightness);
 111
 112
 113#define TEMP 0x33 /* RAM location for temperature */
 114#define SIGN 0x34 /* RAM location for temperature sign */
 115
 116static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf)
 117{
 118
 119        struct usb_interface *intf = to_usb_interface(dev);
 120        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 121
 122        int retval;
 123        unsigned char *buffer;
 124
 125        int temp, sign;
 126   
 127        buffer = kmalloc(8, GFP_KERNEL);
 128        if (!buffer)
 129                return 0;
 130
 131        /* read temperature */
 132        retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
 133        if (retval)
 134                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 135        temp = buffer[1];
 136   
 137        /* read sign */
 138        retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
 139        if (retval)
 140                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 141        sign = buffer[1];
 142
 143        kfree(buffer);
 144   
 145        return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
 146                       5*(temp - ((temp >> 1) << 1)));
 147}
 148static DEVICE_ATTR_RO(temp);
 149
 150
 151#define BUTTON 0x7a
 152
 153static ssize_t button_show(struct device *dev, struct device_attribute *attr, char *buf)
 154{
 155
 156        struct usb_interface *intf = to_usb_interface(dev);
 157        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 158
 159        int retval;
 160        unsigned char *buffer;
 161
 162        buffer = kmalloc(8, GFP_KERNEL);
 163        if (!buffer)
 164                return 0;
 165
 166        /* check button */
 167        retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
 168        if (retval)
 169                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 170   
 171        retval = buffer[1];
 172
 173        kfree(buffer);
 174
 175        if (retval)
 176                return sprintf(buf, "1");
 177        else
 178                return sprintf(buf, "0");
 179}
 180static DEVICE_ATTR_RO(button);
 181
 182
 183static ssize_t port0_show(struct device *dev, struct device_attribute *attr, char *buf)
 184{
 185        struct usb_interface *intf = to_usb_interface(dev);
 186        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 187
 188        int retval;
 189        unsigned char *buffer;
 190
 191        buffer = kmalloc(8, GFP_KERNEL);
 192        if (!buffer)
 193                return 0;
 194
 195        retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
 196        if (retval)
 197                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 198
 199        retval = buffer[1];
 200
 201        kfree(buffer);
 202
 203        return sprintf(buf, "%d", retval);
 204}
 205
 206
 207static ssize_t port0_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 208{
 209        struct usb_interface *intf = to_usb_interface(dev);
 210        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 211
 212        unsigned char *buffer;
 213        int retval;
 214        int tmp;
 215   
 216        buffer = kmalloc(8, GFP_KERNEL);
 217        if (!buffer)
 218                return 0;
 219
 220        tmp = simple_strtoul(buf, NULL, 10);
 221   
 222        if (tmp > 0xFF)
 223                tmp = 0xFF;
 224        else if (tmp < 0)
 225                tmp = 0;
 226   
 227        retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
 228                                tmp, buffer, 8);
 229        if (retval)
 230                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 231
 232        kfree(buffer);
 233
 234        return count;
 235}
 236static DEVICE_ATTR_RW(port0);
 237
 238static ssize_t port1_show(struct device *dev, struct device_attribute *attr, char *buf)
 239{
 240        struct usb_interface *intf = to_usb_interface(dev);
 241        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 242
 243        int retval;
 244        unsigned char *buffer;
 245
 246        buffer = kmalloc(8, GFP_KERNEL);
 247        if (!buffer)
 248                return 0;
 249
 250        retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
 251        if (retval)
 252                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 253   
 254        retval = buffer[1];
 255
 256        kfree(buffer);
 257
 258        return sprintf(buf, "%d", retval);
 259}
 260
 261
 262static ssize_t port1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 263{
 264        struct usb_interface *intf = to_usb_interface(dev);
 265        struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 266
 267        unsigned char *buffer;
 268        int retval;
 269        int tmp;
 270   
 271        buffer = kmalloc(8, GFP_KERNEL);
 272        if (!buffer)
 273                return 0;
 274
 275        tmp = simple_strtoul(buf, NULL, 10);
 276   
 277        if (tmp > 0xFF)
 278                tmp = 0xFF;
 279        else if (tmp < 0)
 280                tmp = 0;
 281   
 282        retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
 283                                tmp, buffer, 8);
 284        if (retval)
 285                dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 286
 287        kfree(buffer);
 288
 289        return count;
 290}
 291static DEVICE_ATTR_RW(port1);
 292
 293static struct attribute *cytherm_attrs[] = {
 294        &dev_attr_brightness.attr,
 295        &dev_attr_temp.attr,
 296        &dev_attr_button.attr,
 297        &dev_attr_port0.attr,
 298        &dev_attr_port1.attr,
 299        NULL,
 300};
 301ATTRIBUTE_GROUPS(cytherm);
 302
 303static int cytherm_probe(struct usb_interface *interface, 
 304                         const struct usb_device_id *id)
 305{
 306        struct usb_device *udev = interface_to_usbdev(interface);
 307        struct usb_cytherm *dev = NULL;
 308        int retval = -ENOMEM;
 309
 310        dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
 311        if (!dev)
 312                goto error_mem;
 313
 314        dev->udev = usb_get_dev(udev);
 315
 316        usb_set_intfdata (interface, dev);
 317
 318        dev->brightness = 0xFF;
 319
 320        dev_info (&interface->dev,
 321                  "Cypress thermometer device now attached\n");
 322        return 0;
 323
 324error_mem:
 325        return retval;
 326}
 327
 328static void cytherm_disconnect(struct usb_interface *interface)
 329{
 330        struct usb_cytherm *dev;
 331
 332        dev = usb_get_intfdata (interface);
 333
 334        /* first remove the files, then NULL the pointer */
 335        usb_set_intfdata (interface, NULL);
 336
 337        usb_put_dev(dev->udev);
 338
 339        kfree(dev);
 340
 341        dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
 342}
 343
 344/* usb specific object needed to register this driver with the usb subsystem */
 345static struct usb_driver cytherm_driver = {
 346        .name =         "cytherm",
 347        .probe =        cytherm_probe,
 348        .disconnect =   cytherm_disconnect,
 349        .id_table =     id_table,
 350        .dev_groups =   cytherm_groups,
 351};
 352
 353module_usb_driver(cytherm_driver);
 354
 355MODULE_AUTHOR(DRIVER_AUTHOR);
 356MODULE_DESCRIPTION(DRIVER_DESC);
 357MODULE_LICENSE("GPL");
 358