linux/drivers/usb/misc/cypress_cy7c63.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3* cypress_cy7c63.c
   4*
   5* Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.de)
   6*
   7*       This driver is based on the Cypress USB Driver by Marcus Maul
   8*       (cyport) and the 2.0 version of Greg Kroah-Hartman's
   9*       USB Skeleton driver.
  10*
  11*       This is a generic driver for the Cypress CY7C63xxx family.
  12*       For the time being it enables you to read from and write to
  13*       the single I/O ports of the device.
  14*
  15*       Supported vendors:      AK Modul-Bus Computer GmbH
  16*                               (Firmware "Port-Chip")
  17*
  18*       Supported devices:      CY7C63001A-PC
  19*                               CY7C63001C-PXC
  20*                               CY7C63001C-SXC
  21*
  22*       Supported functions:    Read/Write Ports
  23*
  24*
  25*       For up-to-date information please visit:
  26*       http://www.obock.de/kernel/cypress
  27*/
  28
  29#include <linux/module.h>
  30#include <linux/kernel.h>
  31#include <linux/slab.h>
  32#include <linux/usb.h>
  33
  34#define DRIVER_AUTHOR           "Oliver Bock (bock@tfh-berlin.de)"
  35#define DRIVER_DESC             "Cypress CY7C63xxx USB driver"
  36
  37#define CYPRESS_VENDOR_ID       0xa2c
  38#define CYPRESS_PRODUCT_ID      0x8
  39
  40#define CYPRESS_READ_PORT       0x4
  41#define CYPRESS_WRITE_PORT      0x5
  42
  43#define CYPRESS_READ_RAM        0x2
  44#define CYPRESS_WRITE_RAM       0x3
  45#define CYPRESS_READ_ROM        0x1
  46
  47#define CYPRESS_READ_PORT_ID0   0
  48#define CYPRESS_WRITE_PORT_ID0  0
  49#define CYPRESS_READ_PORT_ID1   0x2
  50#define CYPRESS_WRITE_PORT_ID1  1
  51
  52#define CYPRESS_MAX_REQSIZE     8
  53
  54
  55/* table of devices that work with this driver */
  56static const struct usb_device_id cypress_table[] = {
  57        { USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
  58        { }
  59};
  60MODULE_DEVICE_TABLE(usb, cypress_table);
  61
  62/* structure to hold all of our device specific stuff */
  63struct cypress {
  64        struct usb_device *     udev;
  65        unsigned char           port[2];
  66};
  67
  68/* used to send usb control messages to device */
  69static int vendor_command(struct cypress *dev, unsigned char request,
  70                          unsigned char address, unsigned char data)
  71{
  72        int retval = 0;
  73        unsigned int pipe;
  74        unsigned char *iobuf;
  75
  76        /* allocate some memory for the i/o buffer*/
  77        iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
  78        if (!iobuf) {
  79                retval = -ENOMEM;
  80                goto error;
  81        }
  82
  83        dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
  84
  85        /* prepare usb control message and send it upstream */
  86        pipe = usb_rcvctrlpipe(dev->udev, 0);
  87        retval = usb_control_msg(dev->udev, pipe, request,
  88                                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  89                                 address, data, iobuf, CYPRESS_MAX_REQSIZE,
  90                                 USB_CTRL_GET_TIMEOUT);
  91
  92        /* store returned data (more READs to be added) */
  93        switch (request) {
  94                case CYPRESS_READ_PORT:
  95                        if (address == CYPRESS_READ_PORT_ID0) {
  96                                dev->port[0] = iobuf[1];
  97                                dev_dbg(&dev->udev->dev,
  98                                        "READ_PORT0 returned: %d\n",
  99                                        dev->port[0]);
 100                        }
 101                        else if (address == CYPRESS_READ_PORT_ID1) {
 102                                dev->port[1] = iobuf[1];
 103                                dev_dbg(&dev->udev->dev,
 104                                        "READ_PORT1 returned: %d\n",
 105                                        dev->port[1]);
 106                        }
 107                        break;
 108        }
 109
 110        kfree(iobuf);
 111error:
 112        return retval;
 113}
 114
 115/* write port value */
 116static ssize_t write_port(struct device *dev, struct device_attribute *attr,
 117                          const char *buf, size_t count,
 118                          int port_num, int write_id)
 119{
 120        int value = -1;
 121        int result = 0;
 122
 123        struct usb_interface *intf = to_usb_interface(dev);
 124        struct cypress *cyp = usb_get_intfdata(intf);
 125
 126        dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
 127
 128        /* validate input data */
 129        if (sscanf(buf, "%d", &value) < 1) {
 130                result = -EINVAL;
 131                goto error;
 132        }
 133        if (value < 0 || value > 255) {
 134                result = -EINVAL;
 135                goto error;
 136        }
 137
 138        result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
 139                                (unsigned char)value);
 140
 141        dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 142error:
 143        return result < 0 ? result : count;
 144}
 145
 146/* attribute callback handler (write) */
 147static ssize_t port0_store(struct device *dev,
 148                                 struct device_attribute *attr,
 149                                 const char *buf, size_t count)
 150{
 151        return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
 152}
 153
 154/* attribute callback handler (write) */
 155static ssize_t port1_store(struct device *dev,
 156                                 struct device_attribute *attr,
 157                                 const char *buf, size_t count)
 158{
 159        return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
 160}
 161
 162/* read port value */
 163static ssize_t read_port(struct device *dev, struct device_attribute *attr,
 164                         char *buf, int port_num, int read_id)
 165{
 166        int result = 0;
 167
 168        struct usb_interface *intf = to_usb_interface(dev);
 169        struct cypress *cyp = usb_get_intfdata(intf);
 170
 171        dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
 172
 173        result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
 174
 175        dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
 176
 177        return sprintf(buf, "%d", cyp->port[port_num]);
 178}
 179
 180/* attribute callback handler (read) */
 181static ssize_t port0_show(struct device *dev,
 182                                 struct device_attribute *attr, char *buf)
 183{
 184        return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
 185}
 186
 187/* attribute callback handler (read) */
 188static ssize_t port1_show(struct device *dev,
 189                                 struct device_attribute *attr, char *buf)
 190{
 191        return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
 192}
 193
 194static DEVICE_ATTR_RW(port0);
 195
 196static DEVICE_ATTR_RW(port1);
 197
 198
 199static int cypress_probe(struct usb_interface *interface,
 200                         const struct usb_device_id *id)
 201{
 202        struct cypress *dev = NULL;
 203        int retval = -ENOMEM;
 204
 205        /* allocate memory for our device state and initialize it */
 206        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 207        if (!dev)
 208                goto error_mem;
 209
 210        dev->udev = usb_get_dev(interface_to_usbdev(interface));
 211
 212        /* save our data pointer in this interface device */
 213        usb_set_intfdata(interface, dev);
 214
 215        /* create device attribute files */
 216        retval = device_create_file(&interface->dev, &dev_attr_port0);
 217        if (retval)
 218                goto error;
 219        retval = device_create_file(&interface->dev, &dev_attr_port1);
 220        if (retval)
 221                goto error;
 222
 223        /* let the user know that the device is now attached */
 224        dev_info(&interface->dev,
 225                 "Cypress CY7C63xxx device now attached\n");
 226        return 0;
 227
 228error:
 229        device_remove_file(&interface->dev, &dev_attr_port0);
 230        device_remove_file(&interface->dev, &dev_attr_port1);
 231        usb_set_intfdata(interface, NULL);
 232        usb_put_dev(dev->udev);
 233        kfree(dev);
 234
 235error_mem:
 236        return retval;
 237}
 238
 239static void cypress_disconnect(struct usb_interface *interface)
 240{
 241        struct cypress *dev;
 242
 243        dev = usb_get_intfdata(interface);
 244
 245        /* remove device attribute files */
 246        device_remove_file(&interface->dev, &dev_attr_port0);
 247        device_remove_file(&interface->dev, &dev_attr_port1);
 248        /* the intfdata can be set to NULL only after the
 249         * device files have been removed */
 250        usb_set_intfdata(interface, NULL);
 251
 252        usb_put_dev(dev->udev);
 253
 254        dev_info(&interface->dev,
 255                 "Cypress CY7C63xxx device now disconnected\n");
 256
 257        kfree(dev);
 258}
 259
 260static struct usb_driver cypress_driver = {
 261        .name = "cypress_cy7c63",
 262        .probe = cypress_probe,
 263        .disconnect = cypress_disconnect,
 264        .id_table = cypress_table,
 265};
 266
 267module_usb_driver(cypress_driver);
 268
 269MODULE_AUTHOR(DRIVER_AUTHOR);
 270MODULE_DESCRIPTION(DRIVER_DESC);
 271
 272MODULE_LICENSE("GPL");
 273