linux/drivers/usb/misc/cypress_cy7c63.c
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   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/module.h>
  33#include <linux/kernel.h>
  34#include <linux/slab.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 */
  59static const struct usb_device_id cypress_table[] = {
  60        { USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
  61        { }
  62};
  63MODULE_DEVICE_TABLE(usb, cypress_table);
  64
  65/* structure to hold all of our device specific stuff */
  66struct cypress {
  67        struct usb_device *     udev;
  68        unsigned char           port[2];
  69};
  70
  71/* used to send usb control messages to device */
  72static 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                retval = -ENOMEM;
  83                goto error;
  84        }
  85
  86        dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
  87
  88        /* prepare usb control message and send it upstream */
  89        pipe = usb_rcvctrlpipe(dev->udev, 0);
  90        retval = usb_control_msg(dev->udev, pipe, request,
  91                                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  92                                 address, data, iobuf, CYPRESS_MAX_REQSIZE,
  93                                 USB_CTRL_GET_TIMEOUT);
  94
  95        /* store returned data (more READs to be added) */
  96        switch (request) {
  97                case CYPRESS_READ_PORT:
  98                        if (address == CYPRESS_READ_PORT_ID0) {
  99                                dev->port[0] = iobuf[1];
 100                                dev_dbg(&dev->udev->dev,
 101                                        "READ_PORT0 returned: %d\n",
 102                                        dev->port[0]);
 103                        }
 104                        else if (address == CYPRESS_READ_PORT_ID1) {
 105                                dev->port[1] = iobuf[1];
 106                                dev_dbg(&dev->udev->dev,
 107                                        "READ_PORT1 returned: %d\n",
 108                                        dev->port[1]);
 109                        }
 110                        break;
 111        }
 112
 113        kfree(iobuf);
 114error:
 115        return retval;
 116}
 117
 118/* write port value */
 119static ssize_t write_port(struct device *dev, struct device_attribute *attr,
 120                          const char *buf, size_t count,
 121                          int port_num, int write_id)
 122{
 123        int value = -1;
 124        int result = 0;
 125
 126        struct usb_interface *intf = to_usb_interface(dev);
 127        struct cypress *cyp = usb_get_intfdata(intf);
 128
 129        dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
 130
 131        /* validate input data */
 132        if (sscanf(buf, "%d", &value) < 1) {
 133                result = -EINVAL;
 134                goto error;
 135        }
 136        if (value < 0 || value > 255) {
 137                result = -EINVAL;
 138                goto error;
 139        }
 140
 141        result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
 142                                (unsigned char)value);
 143
 144        dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 145error:
 146        return result < 0 ? result : count;
 147}
 148
 149/* attribute callback handler (write) */
 150static ssize_t set_port0_handler(struct device *dev,
 151                                 struct device_attribute *attr,
 152                                 const char *buf, size_t count)
 153{
 154        return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
 155}
 156
 157/* attribute callback handler (write) */
 158static ssize_t set_port1_handler(struct device *dev,
 159                                 struct device_attribute *attr,
 160                                 const char *buf, size_t count)
 161{
 162        return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
 163}
 164
 165/* read port value */
 166static ssize_t read_port(struct device *dev, struct device_attribute *attr,
 167                         char *buf, int port_num, int read_id)
 168{
 169        int result = 0;
 170
 171        struct usb_interface *intf = to_usb_interface(dev);
 172        struct cypress *cyp = usb_get_intfdata(intf);
 173
 174        dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
 175
 176        result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
 177
 178        dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 179
 180        return sprintf(buf, "%d", cyp->port[port_num]);
 181}
 182
 183/* attribute callback handler (read) */
 184static ssize_t get_port0_handler(struct device *dev,
 185                                 struct device_attribute *attr, char *buf)
 186{
 187        return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
 188}
 189
 190/* attribute callback handler (read) */
 191static ssize_t get_port1_handler(struct device *dev,
 192                                 struct device_attribute *attr, char *buf)
 193{
 194        return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
 195}
 196
 197static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR, get_port0_handler, set_port0_handler);
 198
 199static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR, get_port1_handler, set_port1_handler);
 200
 201
 202static int cypress_probe(struct usb_interface *interface,
 203                         const struct usb_device_id *id)
 204{
 205        struct cypress *dev = NULL;
 206        int retval = -ENOMEM;
 207
 208        /* allocate memory for our device state and initialize it */
 209        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 210        if (!dev)
 211                goto error_mem;
 212
 213        dev->udev = usb_get_dev(interface_to_usbdev(interface));
 214
 215        /* save our data pointer in this interface device */
 216        usb_set_intfdata(interface, dev);
 217
 218        /* create device attribute files */
 219        retval = device_create_file(&interface->dev, &dev_attr_port0);
 220        if (retval)
 221                goto error;
 222        retval = device_create_file(&interface->dev, &dev_attr_port1);
 223        if (retval)
 224                goto error;
 225
 226        /* let the user know that the device is now attached */
 227        dev_info(&interface->dev,
 228                 "Cypress CY7C63xxx device now attached\n");
 229        return 0;
 230
 231error:
 232        device_remove_file(&interface->dev, &dev_attr_port0);
 233        device_remove_file(&interface->dev, &dev_attr_port1);
 234        usb_set_intfdata(interface, NULL);
 235        usb_put_dev(dev->udev);
 236        kfree(dev);
 237
 238error_mem:
 239        return retval;
 240}
 241
 242static void cypress_disconnect(struct usb_interface *interface)
 243{
 244        struct cypress *dev;
 245
 246        dev = usb_get_intfdata(interface);
 247
 248        /* remove device attribute files */
 249        device_remove_file(&interface->dev, &dev_attr_port0);
 250        device_remove_file(&interface->dev, &dev_attr_port1);
 251        /* the intfdata can be set to NULL only after the
 252         * device files have been removed */
 253        usb_set_intfdata(interface, NULL);
 254
 255        usb_put_dev(dev->udev);
 256
 257        dev_info(&interface->dev,
 258                 "Cypress CY7C63xxx device now disconnected\n");
 259
 260        kfree(dev);
 261}
 262
 263static struct usb_driver cypress_driver = {
 264        .name = "cypress_cy7c63",
 265        .probe = cypress_probe,
 266        .disconnect = cypress_disconnect,
 267        .id_table = cypress_table,
 268};
 269
 270module_usb_driver(cypress_driver);
 271
 272MODULE_AUTHOR(DRIVER_AUTHOR);
 273MODULE_DESCRIPTION(DRIVER_DESC);
 274
 275MODULE_LICENSE("GPL");
 276