/*
* cy7c63.c
*
* Copyright (c) 2006 Oliver Bock (bock@fh-wolfenbuettel.de)
*
*	This driver is based on the Cypress Thermometer USB Driver by
*	Marcus Maul and the 2.0 version of Greg Kroah-Hartman's
*	USB Skeleton driver.
*
*	Is is a generic driver for the Cypress CY7C63000 family.
*	For the time being it enables you to toggle the single I/O ports
*	of the device.
*
*	Supported vendors:	AK Modul-Bus Computer GmbH
*	Supported devices:	CY7C63001A-PC (to be continued...)
*	Supported functions:	Read/Write Ports (to be continued...)
*
*	Chipsets families:	CY7C63000, CY7C63001, CY7C63100, CY7C63101
*
*
*	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/usb.h>

#define DRIVER_AUTHOR		"Oliver Bock (bock@fh-wolfenbuettel.de)"
#define DRIVER_DESC		"Cypress CY7C63xxx USB driver"

#define CY7C63_VENDOR_ID	0xa2c
#define CY7C63_PRODUCT_ID	0x8

#define CY7C63_READ_PORT	0x4
#define CY7C63_WRITE_PORT	0x5
#define CY7C63_READ_RAM		0x2
#define CY7C63_WRITE_RAM	0x3
#define CY7C63_READ_ROM		0x1

#define CY7C63_READ_PORT_ID0	0
#define CY7C63_WRITE_PORT_ID0	0
#define CY7C63_READ_PORT_ID1	0x2
#define CY7C63_WRITE_PORT_ID1	1

#define CY7C63_MAX_REQSIZE	8


/* table of devices that work with this driver */
static struct usb_device_id cy7c63_table [] = {
	{ USB_DEVICE(CY7C63_VENDOR_ID, CY7C63_PRODUCT_ID) },
	{ }
};
MODULE_DEVICE_TABLE(usb, cy7c63_table);

/* structure to hold all of our device specific stuff */
struct cy7c63 {
	struct usb_device *	udev;
	char 			port0;
	char			port1;
};

/* used to send usb control messages to device */
int vendor_command(struct cy7c63 *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(CY7C63_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, CY7C63_MAX_REQSIZE,
				USB_CTRL_GET_TIMEOUT);

	/* store returned data (more READs to be added!) */
	switch (request) {
		case CY7C63_READ_PORT:
			if (address == CY7C63_READ_PORT_ID0) {
				dev->port0 = iobuf[1];
				dev_dbg(&dev->udev->dev,
					"READ_PORT0 returned: %d\n",dev->port0);
			}
			else if (address == CY7C63_READ_PORT_ID1) {
				dev->port1 = iobuf[1];
				dev_dbg(&dev->udev->dev,
					"READ_PORT1 returned: %d\n",dev->port1);
			}
			break;
	}

	kfree(iobuf);
error:
	return retval;
}

#define get_set_port(num,read_id,write_id) \
static ssize_t set_port##num(struct device *dev, struct device_attribute *attr,	\
					const char *buf, size_t count) {	\
										\
	int value;								\
	int result = 0;								\
										\
	struct usb_interface *intf = to_usb_interface(dev);			\
	struct cy7c63 *cyp = usb_get_intfdata(intf);				\
										\
	dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", num);			\
										\
	/* validate input data */						\
	if (sscanf(buf, "%d", &value) < 1) {					\
		result = -EINVAL;						\
		goto error;							\
	}									\
	if (value>255 || value<0) {						\
		result = -EINVAL;						\
		goto error;							\
	}									\
										\
	result = vendor_command(cyp, CY7C63_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;					\
}										\
										\
static ssize_t get_port##num(struct device *dev,				\
				 struct device_attribute *attr, char *buf) {	\
										\
	int result = 0;								\
										\
	struct usb_interface *intf = to_usb_interface(dev);			\
	struct cy7c63 *cyp = usb_get_intfdata(intf);				\
										\
	dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", num);			\
										\
	result = vendor_command(cyp, CY7C63_READ_PORT, read_id, 0);		\
										\
	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);	\
										\
	return sprintf(buf, "%d", cyp->port##num);				\
}										\
static DEVICE_ATTR(port##num, S_IWUGO | S_IRUGO, get_port##num, set_port##num);

get_set_port(0, CY7C63_READ_PORT_ID0, CY7C63_WRITE_PORT_ID0);
get_set_port(1, CY7C63_READ_PORT_ID1, CY7C63_WRITE_PORT_ID1);

static int cy7c63_probe(struct usb_interface *interface,
			const struct usb_device_id *id) {

	struct cy7c63 *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(&dev->udev->dev, "Out of memory!\n");
		goto error;
	}

	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 */
	device_create_file(&interface->dev, &dev_attr_port0);
	device_create_file(&interface->dev, &dev_attr_port1);

	/* let the user know what node this device is now attached to */
	dev_info(&interface->dev,
		"Cypress CY7C63xxx device now attached\n");

	retval = 0;
error:
	return retval;
}

static void cy7c63_disconnect(struct usb_interface *interface) {

	struct cy7c63 *dev;

	dev = usb_get_intfdata(interface);
	usb_set_intfdata(interface, NULL);

	/* remove device attribute files */
	device_remove_file(&interface->dev, &dev_attr_port0);
	device_remove_file(&interface->dev, &dev_attr_port1);

	usb_put_dev(dev->udev);

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

	kfree(dev);
}

static struct usb_driver cy7c63_driver = {
	.name = "cy7c63",
	.probe = cy7c63_probe,
	.disconnect = cy7c63_disconnect,
	.id_table = cy7c63_table,
};

static int __init cy7c63_init(void) {

	int result;

	/* register this driver with the USB subsystem */
	result = usb_register(&cy7c63_driver);
	if (result) {
		err("Function usb_register failed! Error number: %d\n", result);
	}

	return result;
}

static void __exit cy7c63_exit(void) {

	/* deregister this driver with the USB subsystem */
	usb_deregister(&cy7c63_driver);
}

module_init(cy7c63_init);
module_exit(cy7c63_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);

MODULE_LICENSE("GPL");