cypress_cy7c63.c

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/*
* cypress_cy7c63.c
*
* Copyright (c) 2006-2007 Oliver Bock ([email protected])
*
*   This driver is based on the Cypress USB Driver by Marcus Maul
*   (cyport) and the 2.0 version of Greg Kroah-Hartman's
*   USB Skeleton driver.
*
*   This is a generic driver for the Cypress CY7C63xxx family.
*   For the time being it enables you to read from and write to
*   the single I/O ports of the device.
*
*   Supported vendors:  AK Modul-Bus Computer GmbH
*               (Firmware "Port-Chip")
*
*   Supported devices:  CY7C63001A-PC
*               CY7C63001C-PXC
*               CY7C63001C-SXC
*
*   Supported functions:    Read/Write Ports
*
*
*   For up-to-date information please visit:
*   http://www.obock.de/kernel/cypress
*
*   This program is free software; you can redistribute it and/or
*   modify it under the terms of the GNU General Public License as
*   published by the Free Software Foundation, version 2.
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/usb.h>

#define DRIVER_AUTHOR       "Oliver Bock ([email protected])"
#define DRIVER_DESC     "Cypress CY7C63xxx USB driver"

#define CYPRESS_VENDOR_ID   0xa2c
#define CYPRESS_PRODUCT_ID  0x8

#define CYPRESS_READ_PORT   0x4
#define CYPRESS_WRITE_PORT  0x5

#define CYPRESS_READ_RAM    0x2
#define CYPRESS_WRITE_RAM   0x3
#define CYPRESS_READ_ROM    0x1

#define CYPRESS_READ_PORT_ID0   0
#define CYPRESS_WRITE_PORT_ID0  0
#define CYPRESS_READ_PORT_ID1   0x2
#define CYPRESS_WRITE_PORT_ID1  1

#define CYPRESS_MAX_REQSIZE 8


/* table of devices that work with this driver */
static const struct usb_device_id cypress_table[] = {
    { USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
    { }
};
MODULE_DEVICE_TABLE(usb, cypress_table);

/* structure to hold all of our device specific stuff */
struct cypress {
    struct usb_device * udev;
    unsigned char       port[2];
};

/* used to send usb control messages to device */
static int vendor_command(struct cypress *dev, unsigned char request,
              unsigned char address, unsigned char data)
{
    int retval = 0;
    unsigned int pipe;
    unsigned char *iobuf;

    /* allocate some memory for the i/o buffer*/
    iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
    if (!iobuf) {
        dev_err(&dev->udev->dev, "Out of memory!\n");
        retval = -ENOMEM;
        goto error;
    }

    dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);

    /* prepare usb control message and send it upstream */
    pipe = usb_rcvctrlpipe(dev->udev, 0);
    retval = usb_control_msg(dev->udev, pipe, request,
                 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
                 address, data, iobuf, CYPRESS_MAX_REQSIZE,
                 USB_CTRL_GET_TIMEOUT);

    /* store returned data (more READs to be added) */
    switch (request) {
        case CYPRESS_READ_PORT:
            if (address == CYPRESS_READ_PORT_ID0) {
                dev->port[0] = iobuf[1];
                dev_dbg(&dev->udev->dev,
                    "READ_PORT0 returned: %d\n",
                    dev->port[0]);
            }
            else if (address == CYPRESS_READ_PORT_ID1) {
                dev->port[1] = iobuf[1];
                dev_dbg(&dev->udev->dev,
                    "READ_PORT1 returned: %d\n",
                    dev->port[1]);
            }
            break;
    }

    kfree(iobuf);
error:
    return retval;
}

/* write port value */
static ssize_t write_port(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count,
              int port_num, int write_id)
{
    int value = -1;
    int result = 0;

    struct usb_interface *intf = to_usb_interface(dev);
    struct cypress *cyp = usb_get_intfdata(intf);

    dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);

    /* validate input data */
    if (sscanf(buf, "%d", &value) < 1) {
        result = -EINVAL;
        goto error;
    }
    if (value < 0 || value > 255) {
        result = -EINVAL;
        goto error;
    }

    result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
                (unsigned char)value);

    dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
error:
    return result < 0 ? result : count;
}

/* attribute callback handler (write) */
static ssize_t set_port0_handler(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t count)
{
    return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
}

/* attribute callback handler (write) */
static ssize_t set_port1_handler(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t count)
{
    return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
}

/* read port value */
static ssize_t read_port(struct device *dev, struct device_attribute *attr,
             char *buf, int port_num, int read_id)
{
    int result = 0;

    struct usb_interface *intf = to_usb_interface(dev);
    struct cypress *cyp = usb_get_intfdata(intf);

    dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);

    result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);

    dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);

    return sprintf(buf, "%d", cyp->port[port_num]);
}

/* attribute callback handler (read) */
static ssize_t get_port0_handler(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
}

/* attribute callback handler (read) */
static ssize_t get_port1_handler(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
}

static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR, get_port0_handler, set_port0_handler);

static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR, get_port1_handler, set_port1_handler);


static int cypress_probe(struct usb_interface *interface,
             const struct usb_device_id *id)
{
    struct cypress *dev = NULL;
    int retval = -ENOMEM;

    /* allocate memory for our device state and initialize it */
    dev = kzalloc(sizeof(*dev), GFP_KERNEL);
    if (dev == NULL) {
        dev_err(&interface->dev, "Out of memory!\n");
        goto error_mem;
    }

    dev->udev = usb_get_dev(interface_to_usbdev(interface));

    /* save our data pointer in this interface device */
    usb_set_intfdata(interface, dev);

    /* create device attribute files */
    retval = device_create_file(&interface->dev, &dev_attr_port0);
    if (retval)
        goto error;
    retval = device_create_file(&interface->dev, &dev_attr_port1);
    if (retval)
        goto error;

    /* let the user know that the device is now attached */
    dev_info(&interface->dev,
         "Cypress CY7C63xxx device now attached\n");
    return 0;

error:
    device_remove_file(&interface->dev, &dev_attr_port0);
    device_remove_file(&interface->dev, &dev_attr_port1);
    usb_set_intfdata(interface, NULL);
    usb_put_dev(dev->udev);
    kfree(dev);

error_mem:
    return retval;
}

static void cypress_disconnect(struct usb_interface *interface)
{
    struct cypress *dev;

    dev = usb_get_intfdata(interface);

    /* remove device attribute files */
    device_remove_file(&interface->dev, &dev_attr_port0);
    device_remove_file(&interface->dev, &dev_attr_port1);
    /* the intfdata can be set to NULL only after the
     * device files have been removed */
    usb_set_intfdata(interface, NULL);

    usb_put_dev(dev->udev);

    dev_info(&interface->dev,
         "Cypress CY7C63xxx device now disconnected\n");

    kfree(dev);
}

static struct usb_driver cypress_driver = {
    .name = "cypress_cy7c63",
    .probe = cypress_probe,
    .disconnect = cypress_disconnect,
    .id_table = cypress_table,
};

module_usb_driver(cypress_driver);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);

MODULE_LICENSE("GPL");