https://github.com/torvalds/linux
Tip revision: 6a8b55ed4056ea5559ebe4f6a4b247f627870d4c authored by Linus Torvalds on 26 April 2020, 20:51:02 UTC
Linux 5.7-rc3
Linux 5.7-rc3
Tip revision: 6a8b55e
cypress_cy7c63.c
// SPDX-License-Identifier: GPL-2.0
/*
* cypress_cy7c63.c
*
* Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.de)
*
* 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
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/usb.h>
#define DRIVER_AUTHOR "Oliver Bock (bock@tfh-berlin.de)"
#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) {
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 port0_store(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 port1_store(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 port0_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
}
static DEVICE_ATTR_RW(port0);
/* attribute callback handler (read) */
static ssize_t port1_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
}
static DEVICE_ATTR_RW(port1);
static struct attribute *cypress_attrs[] = {
&dev_attr_port0.attr,
&dev_attr_port1.attr,
NULL,
};
ATTRIBUTE_GROUPS(cypress);
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)
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);
/* let the user know that the device is now attached */
dev_info(&interface->dev,
"Cypress CY7C63xxx device now attached\n");
return 0;
error_mem:
return retval;
}
static void cypress_disconnect(struct usb_interface *interface)
{
struct cypress *dev;
dev = usb_get_intfdata(interface);
/* 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,
.dev_groups = cypress_groups,
};
module_usb_driver(cypress_driver);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");