drivers/usb/misc/cypress_cy7c63.c

   1 /*
   2 * cypress_cy7c63.c
   3 *
   4 * Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.de)
   5 *
   6 *       This driver is based on the Cypress USB Driver by Marcus Maul
   7 *       (cyport) and the 2.0 version of Greg Kroah-Hartman's
   8 *       USB Skeleton driver.
   9 *
  10 *       This is a generic driver for the Cypress CY7C63xxx family.
  11 *       For the time being it enables you to read from and write to
  12 *       the single I/O ports of the device.
  13 *
  14 *       Supported vendors:      AK Modul-Bus Computer GmbH
  15 *                               (Firmware "Port-Chip")
  16 *
  17 *       Supported devices:      CY7C63001A-PC
  18 *                               CY7C63001C-PXC
  19 *                               CY7C63001C-SXC
  20 *
  21 *       Supported functions:    Read/Write Ports
  22 *
  23 *
  24 *       For up-to-date information please visit:
  25 *       http://www.obock.de/kernel/cypress
  26 *
  27 *       This program is free software; you can redistribute it and/or
  28 *       modify it under the terms of the GNU General Public License as
  29 *       published by the Free Software Foundation, version 2.
  30 */
  31
  32 #include <linux/init.h>
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/usb.h>
  36
  37 #define DRIVER_AUTHOR           "Oliver Bock (bock@tfh-berlin.de)"
  38 #define DRIVER_DESC             "Cypress CY7C63xxx USB driver"
  39
  40 #define CYPRESS_VENDOR_ID       0xa2c
  41 #define CYPRESS_PRODUCT_ID      0x8
  42
  43 #define CYPRESS_READ_PORT       0x4
  44 #define CYPRESS_WRITE_PORT      0x5
  45
  46 #define CYPRESS_READ_RAM        0x2
  47 #define CYPRESS_WRITE_RAM       0x3
  48 #define CYPRESS_READ_ROM        0x1
  49
  50 #define CYPRESS_READ_PORT_ID0   0
  51 #define CYPRESS_WRITE_PORT_ID0  0
  52 #define CYPRESS_READ_PORT_ID1   0x2
  53 #define CYPRESS_WRITE_PORT_ID1  1
  54
  55 #define CYPRESS_MAX_REQSIZE     8
  56
  57
  58 /* table of devices that work with this driver */
  59 static struct usb_device_id cypress_table [] = {
  60         { USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
  61         { }
  62 };
  63 MODULE_DEVICE_TABLE(usb, cypress_table);
  64
  65 /* structure to hold all of our device specific stuff */
  66 struct cypress {
  67         struct usb_device *     udev;
  68         unsigned char           port[2];
  69 };
  70
  71 /* used to send usb control messages to device */
  72 static int vendor_command(struct cypress *dev, unsigned char request,
  73                           unsigned char address, unsigned char data)
  74 {
  75         int retval = 0;
  76         unsigned int pipe;
  77         unsigned char *iobuf;
  78
  79         /* allocate some memory for the i/o buffer*/
  80         iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
  81         if (!iobuf) {
  82                 dev_err(&dev->udev->dev, "Out of memory!\n");
  83                 retval = -ENOMEM;
  84                 goto error;
  85         }
  86
  87         dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
  88
  89         /* prepare usb control message and send it upstream */
  90         pipe = usb_rcvctrlpipe(dev->udev, 0);
  91         retval = usb_control_msg(dev->udev, pipe, request,
  92                                  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  93                                  address, data, iobuf, CYPRESS_MAX_REQSIZE,
  94                                  USB_CTRL_GET_TIMEOUT);
  95
  96         /* store returned data (more READs to be added) */
  97         switch (request) {
  98                 case CYPRESS_READ_PORT:
  99                         if (address == CYPRESS_READ_PORT_ID0) {
 100                                 dev->port[0] = iobuf[1];
 101                                 dev_dbg(&dev->udev->dev,
 102                                         "READ_PORT0 returned: %d\n",
 103                                         dev->port[0]);
 104                         }
 105                         else if (address == CYPRESS_READ_PORT_ID1) {
 106                                 dev->port[1] = iobuf[1];
 107                                 dev_dbg(&dev->udev->dev,
 108                                         "READ_PORT1 returned: %d\n",
 109                                         dev->port[1]);
 110                         }
 111                         break;
 112         }
 113
 114         kfree(iobuf);
 115 error:
 116         return retval;
 117 }
 118
 119 /* write port value */
 120 static ssize_t write_port(struct device *dev, struct device_attribute *attr,
 121                           const char *buf, size_t count,
 122                           int port_num, int write_id)
 123 {
 124         int value = -1;
 125         int result = 0;
 126
 127         struct usb_interface *intf = to_usb_interface(dev);
 128         struct cypress *cyp = usb_get_intfdata(intf);
 129
 130         dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
 131
 132         /* validate input data */
 133         if (sscanf(buf, "%d", &value) < 1) {
 134                 result = -EINVAL;
 135                 goto error;
 136         }
 137         if (value < 0 || value > 255) {
 138                 result = -EINVAL;
 139                 goto error;
 140         }
 141
 142         result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
 143                                 (unsigned char)value);
 144
 145         dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 146 error:
 147         return result < 0 ? result : count;
 148 }
 149
 150 /* attribute callback handler (write) */
 151 static ssize_t set_port0_handler(struct device *dev,
 152                                  struct device_attribute *attr,
 153                                  const char *buf, size_t count)
 154 {
 155         return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
 156 }
 157
 158 /* attribute callback handler (write) */
 159 static ssize_t set_port1_handler(struct device *dev,
 160                                  struct device_attribute *attr,
 161                                  const char *buf, size_t count)
 162 {
 163         return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
 164 }
 165
 166 /* read port value */
 167 static ssize_t read_port(struct device *dev, struct device_attribute *attr,
 168                          char *buf, int port_num, int read_id)
 169 {
 170         int result = 0;
 171
 172         struct usb_interface *intf = to_usb_interface(dev);
 173         struct cypress *cyp = usb_get_intfdata(intf);
 174
 175         dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
 176
 177         result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
 178
 179         dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 180
 181         return sprintf(buf, "%d", cyp->port[port_num]);
 182 }
 183
 184 /* attribute callback handler (read) */
 185 static ssize_t get_port0_handler(struct device *dev,
 186                                  struct device_attribute *attr, char *buf)
 187 {
 188         return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
 189 }
 190
 191 /* attribute callback handler (read) */
 192 static ssize_t get_port1_handler(struct device *dev,
 193                                  struct device_attribute *attr, char *buf)
 194 {
 195         return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
 196 }
 197
 198 static DEVICE_ATTR(port0, S_IWUGO | S_IRUGO,
 199                    get_port0_handler, set_port0_handler);
 200
 201 static DEVICE_ATTR(port1, S_IWUGO | S_IRUGO,
 202                    get_port1_handler, set_port1_handler);
 203
 204
 205 static int cypress_probe(struct usb_interface *interface,
 206                          const struct usb_device_id *id)
 207 {
 208         struct cypress *dev = NULL;
 209         int retval = -ENOMEM;
 210
 211         /* allocate memory for our device state and initialize it */
 212         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 213         if (dev == NULL) {
 214                 dev_err(&interface->dev, "Out of memory!\n");
 215                 goto error_mem;
 216         }
 217
 218         dev->udev = usb_get_dev(interface_to_usbdev(interface));
 219
 220         /* save our data pointer in this interface device */
 221         usb_set_intfdata(interface, dev);
 222
 223         /* create device attribute files */
 224         retval = device_create_file(&interface->dev, &dev_attr_port0);
 225         if (retval)
 226                 goto error;
 227         retval = device_create_file(&interface->dev, &dev_attr_port1);
 228         if (retval)
 229                 goto error;
 230
 231         /* let the user know that the device is now attached */
 232         dev_info(&interface->dev,
 233                  "Cypress CY7C63xxx device now attached\n");
 234         return 0;
 235
 236 error:
 237         device_remove_file(&interface->dev, &dev_attr_port0);
 238         device_remove_file(&interface->dev, &dev_attr_port1);
 239         usb_set_intfdata(interface, NULL);
 240         usb_put_dev(dev->udev);
 241         kfree(dev);
 242
 243 error_mem:
 244         return retval;
 245 }
 246
 247 static void cypress_disconnect(struct usb_interface *interface)
 248 {
 249         struct cypress *dev;
 250
 251         dev = usb_get_intfdata(interface);
 252
 253         /* remove device attribute files */
 254         device_remove_file(&interface->dev, &dev_attr_port0);
 255         device_remove_file(&interface->dev, &dev_attr_port1);
 256         /* the intfdata can be set to NULL only after the
 257          * device files have been removed */
 258         usb_set_intfdata(interface, NULL);
 259
 260         usb_put_dev(dev->udev);
 261
 262         dev_info(&interface->dev,
 263                  "Cypress CY7C63xxx device now disconnected\n");
 264
 265         kfree(dev);
 266 }
 267
 268 static struct usb_driver cypress_driver = {
 269         .name = "cypress_cy7c63",
 270         .probe = cypress_probe,
 271         .disconnect = cypress_disconnect,
 272         .id_table = cypress_table,
 273 };
 274
 275 static int __init cypress_init(void)
 276 {
 277         int result;
 278
 279         /* register this driver with the USB subsystem */
 280         result = usb_register(&cypress_driver);
 281         if (result) {
 282                 err("Function usb_register failed! Error number: %d\n", result);
 283         }
 284
 285         return result;
 286 }
 287
 288 static void __exit cypress_exit(void)
 289 {
 290         /* deregister this driver with the USB subsystem */
 291         usb_deregister(&cypress_driver);
 292 }
 293
 294 module_init(cypress_init);
 295 module_exit(cypress_exit);
 296
 297 MODULE_AUTHOR(DRIVER_AUTHOR);
 298 MODULE_DESCRIPTION(DRIVER_DESC);
 299
 300 MODULE_LICENSE("GPL");