/*****************************************************************************
*
* Author: Xilinx, Inc.
*
* 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; either version 2 of the License, or (at your
* option) any later version.
*
* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
* AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
* SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
* OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
* APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
* THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
* AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
* FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
* WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
* IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
* REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
* INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
* (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
* (c) Copyright 2007-2008 Xilinx Inc.
* All rights reserved.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*****************************************************************************/
/*
* This is the code behind /dev/icap* -- it allows a user-space
* application to use the Xilinx ICAP subsystem.
*
* The following operations are possible:
*
* open open the port and initialize for access.
* release release port
* write Write a bitstream to the configuration processor.
* read Read a data stream from the configuration processor.
*
* After being opened, the port is initialized and accessed to avoid a
* corrupted first read which may occur with some hardware. The port
* is left in a desynched state, requiring that a synch sequence be
* transmitted before any valid configuration data. A user will have
* exclusive access to the device while it remains open, and the state
* of the ICAP cannot be guaranteed after the device is closed. Note
* that a complete reset of the core and the state of the ICAP cannot
* be performed on many versions of the cores, hence users of this
* device should avoid making inconsistent accesses to the device. In
* particular, accessing the read interface, without first generating
* a write containing a readback packet can leave the ICAP in an
* inaccessible state.
*
* Note that in order to use the read interface, it is first necessary
* to write a request packet to the write interface. i.e., it is not
* possible to simply readback the bitstream (or any configuration
* bits) from a device without specifically requesting them first.
* The code to craft such packets is intended to be part of the
* user-space application code that uses this device. The simplest
* way to use this interface is simply:
*
* cp foo.bit /dev/icap0
*
* Note that unless foo.bit is an appropriately constructed partial
* bitstream, this has a high likelihood of overwriting the design
* currently programmed in the FPGA.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/sysctl.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include "xilinx_hwicap.h"
#include "buffer_icap.h"
#include "fifo_icap.h"
#define DRIVER_NAME "icap"
#define HWICAP_REGS (0x10000)
#define XHWICAP_MAJOR 259
#define XHWICAP_MINOR 0
#define HWICAP_DEVICES 1
/* An array, which is set to true when the device is registered. */
static DEFINE_MUTEX(hwicap_mutex);
static bool probed_devices[HWICAP_DEVICES];
static struct mutex icap_sem;
static const struct class icap_class = {
.name = "xilinx_config",
};
#define UNIMPLEMENTED 0xFFFF
static const struct config_registers v2_config_registers = {
.CRC = 0,
.FAR = 1,
.FDRI = 2,
.FDRO = 3,
.CMD = 4,
.CTL = 5,
.MASK = 6,
.STAT = 7,
.LOUT = 8,
.COR = 9,
.MFWR = 10,
.FLR = 11,
.KEY = 12,
.CBC = 13,
.IDCODE = 14,
.AXSS = UNIMPLEMENTED,
.C0R_1 = UNIMPLEMENTED,
.CSOB = UNIMPLEMENTED,
.WBSTAR = UNIMPLEMENTED,
.TIMER = UNIMPLEMENTED,
.BOOTSTS = UNIMPLEMENTED,
.CTL_1 = UNIMPLEMENTED,
};
static const struct config_registers v4_config_registers = {
.CRC = 0,
.FAR = 1,
.FDRI = 2,
.FDRO = 3,
.CMD = 4,
.CTL = 5,
.MASK = 6,
.STAT = 7,
.LOUT = 8,
.COR = 9,
.MFWR = 10,
.FLR = UNIMPLEMENTED,
.KEY = UNIMPLEMENTED,
.CBC = 11,
.IDCODE = 12,
.AXSS = 13,
.C0R_1 = UNIMPLEMENTED,
.CSOB = UNIMPLEMENTED,
.WBSTAR = UNIMPLEMENTED,
.TIMER = UNIMPLEMENTED,
.BOOTSTS = UNIMPLEMENTED,
.CTL_1 = UNIMPLEMENTED,
};
static const struct config_registers v5_config_registers = {
.CRC = 0,
.FAR = 1,
.FDRI = 2,
.FDRO = 3,
.CMD = 4,
.CTL = 5,
.MASK = 6,
.STAT = 7,
.LOUT = 8,
.COR = 9,
.MFWR = 10,
.FLR = UNIMPLEMENTED,
.KEY = UNIMPLEMENTED,
.CBC = 11,
.IDCODE = 12,
.AXSS = 13,
.C0R_1 = 14,
.CSOB = 15,
.WBSTAR = 16,
.TIMER = 17,
.BOOTSTS = 18,
.CTL_1 = 19,
};
static const struct config_registers v6_config_registers = {
.CRC = 0,
.FAR = 1,
.FDRI = 2,
.FDRO = 3,
.CMD = 4,
.CTL = 5,
.MASK = 6,
.STAT = 7,
.LOUT = 8,
.COR = 9,
.MFWR = 10,
.FLR = UNIMPLEMENTED,
.KEY = UNIMPLEMENTED,
.CBC = 11,
.IDCODE = 12,
.AXSS = 13,
.C0R_1 = 14,
.CSOB = 15,
.WBSTAR = 16,
.TIMER = 17,
.BOOTSTS = 22,
.CTL_1 = 24,
};
/**
* hwicap_command_desync - Send a DESYNC command to the ICAP port.
* @drvdata: a pointer to the drvdata.
*
* Returns: '0' on success and failure value on error
*
* This command desynchronizes the ICAP After this command, a
* bitstream containing a NULL packet, followed by a SYNCH packet is
* required before the ICAP will recognize commands.
*/
static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
{
u32 buffer[4];
u32 index = 0;
/*
* Create the data to be written to the ICAP.
*/
buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
buffer[index++] = XHI_CMD_DESYNCH;
buffer[index++] = XHI_NOOP_PACKET;
buffer[index++] = XHI_NOOP_PACKET;
/*
* Write the data to the FIFO and initiate the transfer of data present
* in the FIFO to the ICAP device.
*/
return drvdata->config->set_configuration(drvdata,
&buffer[0], index);
}
/**
* hwicap_get_configuration_register - Query a configuration register.
* @drvdata: a pointer to the drvdata.
* @reg: a constant which represents the configuration
* register value to be returned.
* Examples: XHI_IDCODE, XHI_FLR.
* @reg_data: returns the value of the register.
*
* Returns: '0' on success and failure value on error
*
* Sends a query packet to the ICAP and then receives the response.
* The icap is left in Synched state.
*/
static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
u32 reg, u32 *reg_data)
{
int status;
u32 buffer[6];
u32 index = 0;
/*
* Create the data to be written to the ICAP.
*/
buffer[index++] = XHI_DUMMY_PACKET;
buffer[index++] = XHI_NOOP_PACKET;
buffer[index++] = XHI_SYNC_PACKET;
buffer[index++] = XHI_NOOP_PACKET;
buffer[index++] = XHI_NOOP_PACKET;
/*
* Write the data to the FIFO and initiate the transfer of data present
* in the FIFO to the ICAP device.
*/
status = drvdata->config->set_configuration(drvdata,
&buffer[0], index);
if (status)
return status;
/* If the syncword was not found, then we need to start over. */
status = drvdata->config->get_status(drvdata);
if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
return -EIO;
index = 0;
buffer[index++] = hwicap_type_1_read(reg) | 1;
buffer[index++] = XHI_NOOP_PACKET;
buffer[index++] = XHI_NOOP_PACKET;
/*
* Write the data to the FIFO and initiate the transfer of data present
* in the FIFO to the ICAP device.
*/
status = drvdata->config->set_configuration(drvdata,
&buffer[0], index);
if (status)
return status;
/*
* Read the configuration register
*/
status = drvdata->config->get_configuration(drvdata, reg_data, 1);
if (status)
return status;
return 0;
}
static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
{
int status;
u32 idcode;
dev_dbg(drvdata->dev, "initializing\n");
/* Abort any current transaction, to make sure we have the
* ICAP in a good state.
*/
dev_dbg(drvdata->dev, "Reset...\n");
drvdata->config->reset(drvdata);
dev_dbg(drvdata->dev, "Desync...\n");
status = hwicap_command_desync(drvdata);
if (status)
return status;
/* Attempt to read the IDCODE from ICAP. This
* may not be returned correctly, due to the design of the
* hardware.
*/
dev_dbg(drvdata->dev, "Reading IDCODE...\n");
status = hwicap_get_configuration_register(
drvdata, drvdata->config_regs->IDCODE, &idcode);
dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
if (status)
return status;
dev_dbg(drvdata->dev, "Desync...\n");
status = hwicap_command_desync(drvdata);
if (status)
return status;
return 0;
}
static ssize_t
hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
struct hwicap_drvdata *drvdata = file->private_data;
ssize_t bytes_to_read = 0;
u32 *kbuf;
u32 words;
u32 bytes_remaining;
int status;
status = mutex_lock_interruptible(&drvdata->sem);
if (status)
return status;
if (drvdata->read_buffer_in_use) {
/* If there are leftover bytes in the buffer, just */
/* return them and don't try to read more from the */
/* ICAP device. */
bytes_to_read =
(count < drvdata->read_buffer_in_use) ? count :
drvdata->read_buffer_in_use;
/* Return the data currently in the read buffer. */
if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
status = -EFAULT;
goto error;
}
drvdata->read_buffer_in_use -= bytes_to_read;
memmove(drvdata->read_buffer,
drvdata->read_buffer + bytes_to_read,
4 - bytes_to_read);
} else {
/* Get new data from the ICAP, and return what was requested. */
kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
if (!kbuf) {
status = -ENOMEM;
goto error;
}
/* The ICAP device is only able to read complete */
/* words. If a number of bytes that do not correspond */
/* to complete words is requested, then we read enough */
/* words to get the required number of bytes, and then */
/* save the remaining bytes for the next read. */
/* Determine the number of words to read, rounding up */
/* if necessary. */
words = ((count + 3) >> 2);
bytes_to_read = words << 2;
if (bytes_to_read > PAGE_SIZE)
bytes_to_read = PAGE_SIZE;
/* Ensure we only read a complete number of words. */
bytes_remaining = bytes_to_read & 3;
bytes_to_read &= ~3;
words = bytes_to_read >> 2;
status = drvdata->config->get_configuration(drvdata,
kbuf, words);
/* If we didn't read correctly, then bail out. */
if (status) {
free_page((unsigned long)kbuf);
goto error;
}
/* If we fail to return the data to the user, then bail out. */
if (copy_to_user(buf, kbuf, bytes_to_read)) {
free_page((unsigned long)kbuf);
status = -EFAULT;
goto error;
}
memcpy(drvdata->read_buffer,
kbuf,
bytes_remaining);
drvdata->read_buffer_in_use = bytes_remaining;
free_page((unsigned long)kbuf);
}
status = bytes_to_read;
error:
mutex_unlock(&drvdata->sem);
return status;
}
static ssize_t
hwicap_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct hwicap_drvdata *drvdata = file->private_data;
ssize_t written = 0;
ssize_t left = count;
u32 *kbuf;
ssize_t len;
ssize_t status;
status = mutex_lock_interruptible(&drvdata->sem);
if (status)
return status;
left += drvdata->write_buffer_in_use;
/* Only write multiples of 4 bytes. */
if (left < 4) {
status = 0;
goto error;
}
kbuf = (u32 *) __get_free_page(GFP_KERNEL);
if (!kbuf) {
status = -ENOMEM;
goto error;
}
while (left > 3) {
/* only write multiples of 4 bytes, so there might */
/* be as many as 3 bytes left (at the end). */
len = left;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
len &= ~3;
if (drvdata->write_buffer_in_use) {
memcpy(kbuf, drvdata->write_buffer,
drvdata->write_buffer_in_use);
if (copy_from_user(
(((char *)kbuf) + drvdata->write_buffer_in_use),
buf + written,
len - (drvdata->write_buffer_in_use))) {
free_page((unsigned long)kbuf);
status = -EFAULT;
goto error;
}
} else {
if (copy_from_user(kbuf, buf + written, len)) {
free_page((unsigned long)kbuf);
status = -EFAULT;
goto error;
}
}
status = drvdata->config->set_configuration(drvdata,
kbuf, len >> 2);
if (status) {
free_page((unsigned long)kbuf);
status = -EFAULT;
goto error;
}
if (drvdata->write_buffer_in_use) {
len -= drvdata->write_buffer_in_use;
left -= drvdata->write_buffer_in_use;
drvdata->write_buffer_in_use = 0;
}
written += len;
left -= len;
}
if ((left > 0) && (left < 4)) {
if (!copy_from_user(drvdata->write_buffer,
buf + written, left)) {
drvdata->write_buffer_in_use = left;
written += left;
left = 0;
}
}
free_page((unsigned long)kbuf);
status = written;
error:
mutex_unlock(&drvdata->sem);
return status;
}
static int hwicap_open(struct inode *inode, struct file *file)
{
struct hwicap_drvdata *drvdata;
int status;
mutex_lock(&hwicap_mutex);
drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);
status = mutex_lock_interruptible(&drvdata->sem);
if (status)
goto out;
if (drvdata->is_open) {
status = -EBUSY;
goto error;
}
status = hwicap_initialize_hwicap(drvdata);
if (status) {
dev_err(drvdata->dev, "Failed to open file");
goto error;
}
file->private_data = drvdata;
drvdata->write_buffer_in_use = 0;
drvdata->read_buffer_in_use = 0;
drvdata->is_open = 1;
error:
mutex_unlock(&drvdata->sem);
out:
mutex_unlock(&hwicap_mutex);
return status;
}
static int hwicap_release(struct inode *inode, struct file *file)
{
struct hwicap_drvdata *drvdata = file->private_data;
int i;
int status = 0;
mutex_lock(&drvdata->sem);
if (drvdata->write_buffer_in_use) {
/* Flush write buffer. */
for (i = drvdata->write_buffer_in_use; i < 4; i++)
drvdata->write_buffer[i] = 0;
status = drvdata->config->set_configuration(drvdata,
(u32 *) drvdata->write_buffer, 1);
if (status)
goto error;
}
status = hwicap_command_desync(drvdata);
if (status)
goto error;
error:
drvdata->is_open = 0;
mutex_unlock(&drvdata->sem);
return status;
}
static const struct file_operations hwicap_fops = {
.owner = THIS_MODULE,
.write = hwicap_write,
.read = hwicap_read,
.open = hwicap_open,
.release = hwicap_release,
.llseek = noop_llseek,
};
static int hwicap_setup(struct platform_device *pdev, int id,
const struct hwicap_driver_config *config,
const struct config_registers *config_regs)
{
dev_t devt;
struct hwicap_drvdata *drvdata = NULL;
struct device *dev = &pdev->dev;
int retval;
dev_info(dev, "Xilinx icap port driver\n");
mutex_lock(&icap_sem);
if (id < 0) {
for (id = 0; id < HWICAP_DEVICES; id++)
if (!probed_devices[id])
break;
}
if (id < 0 || id >= HWICAP_DEVICES) {
mutex_unlock(&icap_sem);
dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
return -EINVAL;
}
if (probed_devices[id]) {
mutex_unlock(&icap_sem);
dev_err(dev, "cannot assign to %s%i; it is already in use\n",
DRIVER_NAME, id);
return -EBUSY;
}
probed_devices[id] = 1;
mutex_unlock(&icap_sem);
devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);
drvdata = devm_kzalloc(dev, sizeof(struct hwicap_drvdata), GFP_KERNEL);
if (!drvdata) {
retval = -ENOMEM;
goto failed;
}
dev_set_drvdata(dev, drvdata);
drvdata->base_address = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(drvdata->base_address)) {
retval = PTR_ERR(drvdata->base_address);
goto failed;
}
drvdata->devt = devt;
drvdata->dev = dev;
drvdata->config = config;
drvdata->config_regs = config_regs;
mutex_init(&drvdata->sem);
drvdata->is_open = 0;
cdev_init(&drvdata->cdev, &hwicap_fops);
drvdata->cdev.owner = THIS_MODULE;
retval = cdev_add(&drvdata->cdev, devt, 1);
if (retval) {
dev_err(dev, "cdev_add() failed\n");
goto failed;
}
device_create(&icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
return 0; /* success */
failed:
mutex_lock(&icap_sem);
probed_devices[id] = 0;
mutex_unlock(&icap_sem);
return retval;
}
static struct hwicap_driver_config buffer_icap_config = {
.get_configuration = buffer_icap_get_configuration,
.set_configuration = buffer_icap_set_configuration,
.get_status = buffer_icap_get_status,
.reset = buffer_icap_reset,
};
static struct hwicap_driver_config fifo_icap_config = {
.get_configuration = fifo_icap_get_configuration,
.set_configuration = fifo_icap_set_configuration,
.get_status = fifo_icap_get_status,
.reset = fifo_icap_reset,
};
static int hwicap_drv_probe(struct platform_device *pdev)
{
const struct config_registers *regs;
const struct hwicap_driver_config *config;
const char *family;
int id = -1;
config = device_get_match_data(&pdev->dev);
of_property_read_u32(pdev->dev.of_node, "port-number", &id);
/* It's most likely that we're using V4, if the family is not
* specified
*/
regs = &v4_config_registers;
if (!of_property_read_string(pdev->dev.of_node, "xlnx,family", &family)) {
if (!strcmp(family, "virtex2p"))
regs = &v2_config_registers;
else if (!strcmp(family, "virtex4"))
regs = &v4_config_registers;
else if (!strcmp(family, "virtex5"))
regs = &v5_config_registers;
else if (!strcmp(family, "virtex6"))
regs = &v6_config_registers;
}
return hwicap_setup(pdev, id, config, regs);
}
static void hwicap_drv_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct hwicap_drvdata *drvdata;
drvdata = dev_get_drvdata(dev);
device_destroy(&icap_class, drvdata->devt);
cdev_del(&drvdata->cdev);
mutex_lock(&icap_sem);
probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
mutex_unlock(&icap_sem);
}
/* Match table for device tree binding */
static const struct of_device_id hwicap_of_match[] = {
{ .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
{ .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
{},
};
MODULE_DEVICE_TABLE(of, hwicap_of_match);
static struct platform_driver hwicap_platform_driver = {
.probe = hwicap_drv_probe,
.remove_new = hwicap_drv_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = hwicap_of_match,
},
};
static int __init hwicap_module_init(void)
{
dev_t devt;
int retval;
retval = class_register(&icap_class);
if (retval)
return retval;
mutex_init(&icap_sem);
devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
retval = register_chrdev_region(devt,
HWICAP_DEVICES,
DRIVER_NAME);
if (retval < 0)
return retval;
retval = platform_driver_register(&hwicap_platform_driver);
if (retval)
goto failed;
return retval;
failed:
unregister_chrdev_region(devt, HWICAP_DEVICES);
return retval;
}
static void __exit hwicap_module_cleanup(void)
{
dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
class_unregister(&icap_class);
platform_driver_unregister(&hwicap_platform_driver);
unregister_chrdev_region(devt, HWICAP_DEVICES);
}
module_init(hwicap_module_init);
module_exit(hwicap_module_cleanup);
MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
MODULE_LICENSE("GPL");
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