1 /*****************************************************************************
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
10 * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
11 * AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
12 * SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
13 * OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
14 * APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
15 * THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
16 * AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
17 * FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
18 * WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
19 * IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
20 * REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
21 * INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22 * FOR A PARTICULAR PURPOSE.
24 * (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
25 * (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
26 * (c) Copyright 2007-2008 Xilinx Inc.
27 * All rights reserved.
29 * You should have received a copy of the GNU General Public License along
30 * with this program; if not, write to the Free Software Foundation, Inc.,
31 * 675 Mass Ave, Cambridge, MA 02139, USA.
33 *****************************************************************************/
36 * This is the code behind /dev/icap* -- it allows a user-space
37 * application to use the Xilinx ICAP subsystem.
39 * The following operations are possible:
41 * open open the port and initialize for access.
42 * release release port
43 * write Write a bitstream to the configuration processor.
44 * read Read a data stream from the configuration processor.
46 * After being opened, the port is initialized and accessed to avoid a
47 * corrupted first read which may occur with some hardware. The port
48 * is left in a desynched state, requiring that a synch sequence be
49 * transmitted before any valid configuration data. A user will have
50 * exclusive access to the device while it remains open, and the state
51 * of the ICAP cannot be guaranteed after the device is closed. Note
52 * that a complete reset of the core and the state of the ICAP cannot
53 * be performed on many versions of the cores, hence users of this
54 * device should avoid making inconsistent accesses to the device. In
55 * particular, accessing the read interface, without first generating
56 * a write containing a readback packet can leave the ICAP in an
59 * Note that in order to use the read interface, it is first necessary
60 * to write a request packet to the write interface. i.e., it is not
61 * possible to simply readback the bitstream (or any configuration
62 * bits) from a device without specifically requesting them first.
63 * The code to craft such packets is intended to be part of the
64 * user-space application code that uses this device. The simplest
65 * way to use this interface is simply:
67 * cp foo.bit /dev/icap0
69 * Note that unless foo.bit is an appropriately constructed partial
70 * bitstream, this has a high likelihood of overwriting the design
71 * currently programmed in the FPGA.
74 #include <linux/module.h>
75 #include <linux/kernel.h>
76 #include <linux/types.h>
77 #include <linux/ioport.h>
78 #include <linux/interrupt.h>
79 #include <linux/fcntl.h>
80 #include <linux/init.h>
81 #include <linux/poll.h>
82 #include <linux/proc_fs.h>
83 #include <linux/mutex.h>
84 #include <linux/sysctl.h>
86 #include <linux/cdev.h>
87 #include <linux/platform_device.h>
88 #include <linux/slab.h>
90 #include <linux/uaccess.h>
93 /* For open firmware. */
94 #include <linux/of_address.h>
95 #include <linux/of_device.h>
96 #include <linux/of_platform.h>
99 #include "xilinx_hwicap.h"
100 #include "buffer_icap.h"
101 #include "fifo_icap.h"
103 #define DRIVER_NAME "icap"
105 #define HWICAP_REGS (0x10000)
107 #define XHWICAP_MAJOR 259
108 #define XHWICAP_MINOR 0
109 #define HWICAP_DEVICES 1
111 /* An array, which is set to true when the device is registered. */
112 static DEFINE_MUTEX(hwicap_mutex);
113 static bool probed_devices[HWICAP_DEVICES];
114 static struct mutex icap_sem;
116 static struct class *icap_class;
118 #define UNIMPLEMENTED 0xFFFF
120 static const struct config_registers v2_config_registers = {
136 .AXSS = UNIMPLEMENTED,
137 .C0R_1 = UNIMPLEMENTED,
138 .CSOB = UNIMPLEMENTED,
139 .WBSTAR = UNIMPLEMENTED,
140 .TIMER = UNIMPLEMENTED,
141 .BOOTSTS = UNIMPLEMENTED,
142 .CTL_1 = UNIMPLEMENTED,
145 static const struct config_registers v4_config_registers = {
157 .FLR = UNIMPLEMENTED,
158 .KEY = UNIMPLEMENTED,
162 .C0R_1 = UNIMPLEMENTED,
163 .CSOB = UNIMPLEMENTED,
164 .WBSTAR = UNIMPLEMENTED,
165 .TIMER = UNIMPLEMENTED,
166 .BOOTSTS = UNIMPLEMENTED,
167 .CTL_1 = UNIMPLEMENTED,
170 static const struct config_registers v5_config_registers = {
182 .FLR = UNIMPLEMENTED,
183 .KEY = UNIMPLEMENTED,
195 static const struct config_registers v6_config_registers = {
207 .FLR = UNIMPLEMENTED,
208 .KEY = UNIMPLEMENTED,
221 * hwicap_command_desync - Send a DESYNC command to the ICAP port.
222 * @drvdata: a pointer to the drvdata.
224 * Returns: '0' on success and failure value on error
226 * This command desynchronizes the ICAP After this command, a
227 * bitstream containing a NULL packet, followed by a SYNCH packet is
228 * required before the ICAP will recognize commands.
230 static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
236 * Create the data to be written to the ICAP.
238 buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
239 buffer[index++] = XHI_CMD_DESYNCH;
240 buffer[index++] = XHI_NOOP_PACKET;
241 buffer[index++] = XHI_NOOP_PACKET;
244 * Write the data to the FIFO and intiate the transfer of data present
245 * in the FIFO to the ICAP device.
247 return drvdata->config->set_configuration(drvdata,
252 * hwicap_get_configuration_register - Query a configuration register.
253 * @drvdata: a pointer to the drvdata.
254 * @reg: a constant which represents the configuration
255 * register value to be returned.
256 * Examples: XHI_IDCODE, XHI_FLR.
257 * @reg_data: returns the value of the register.
259 * Returns: '0' on success and failure value on error
261 * Sends a query packet to the ICAP and then receives the response.
262 * The icap is left in Synched state.
264 static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
265 u32 reg, u32 *reg_data)
272 * Create the data to be written to the ICAP.
274 buffer[index++] = XHI_DUMMY_PACKET;
275 buffer[index++] = XHI_NOOP_PACKET;
276 buffer[index++] = XHI_SYNC_PACKET;
277 buffer[index++] = XHI_NOOP_PACKET;
278 buffer[index++] = XHI_NOOP_PACKET;
281 * Write the data to the FIFO and initiate the transfer of data present
282 * in the FIFO to the ICAP device.
284 status = drvdata->config->set_configuration(drvdata,
289 /* If the syncword was not found, then we need to start over. */
290 status = drvdata->config->get_status(drvdata);
291 if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
295 buffer[index++] = hwicap_type_1_read(reg) | 1;
296 buffer[index++] = XHI_NOOP_PACKET;
297 buffer[index++] = XHI_NOOP_PACKET;
300 * Write the data to the FIFO and intiate the transfer of data present
301 * in the FIFO to the ICAP device.
303 status = drvdata->config->set_configuration(drvdata,
309 * Read the configuration register
311 status = drvdata->config->get_configuration(drvdata, reg_data, 1);
318 static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
323 dev_dbg(drvdata->dev, "initializing\n");
325 /* Abort any current transaction, to make sure we have the
326 * ICAP in a good state.
328 dev_dbg(drvdata->dev, "Reset...\n");
329 drvdata->config->reset(drvdata);
331 dev_dbg(drvdata->dev, "Desync...\n");
332 status = hwicap_command_desync(drvdata);
336 /* Attempt to read the IDCODE from ICAP. This
337 * may not be returned correctly, due to the design of the
340 dev_dbg(drvdata->dev, "Reading IDCODE...\n");
341 status = hwicap_get_configuration_register(
342 drvdata, drvdata->config_regs->IDCODE, &idcode);
343 dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
347 dev_dbg(drvdata->dev, "Desync...\n");
348 status = hwicap_command_desync(drvdata);
356 hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
358 struct hwicap_drvdata *drvdata = file->private_data;
359 ssize_t bytes_to_read = 0;
365 status = mutex_lock_interruptible(&drvdata->sem);
369 if (drvdata->read_buffer_in_use) {
370 /* If there are leftover bytes in the buffer, just */
371 /* return them and don't try to read more from the */
374 (count < drvdata->read_buffer_in_use) ? count :
375 drvdata->read_buffer_in_use;
377 /* Return the data currently in the read buffer. */
378 if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
382 drvdata->read_buffer_in_use -= bytes_to_read;
383 memmove(drvdata->read_buffer,
384 drvdata->read_buffer + bytes_to_read,
387 /* Get new data from the ICAP, and return was was requested. */
388 kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
394 /* The ICAP device is only able to read complete */
395 /* words. If a number of bytes that do not correspond */
396 /* to complete words is requested, then we read enough */
397 /* words to get the required number of bytes, and then */
398 /* save the remaining bytes for the next read. */
400 /* Determine the number of words to read, rounding up */
402 words = ((count + 3) >> 2);
403 bytes_to_read = words << 2;
405 if (bytes_to_read > PAGE_SIZE)
406 bytes_to_read = PAGE_SIZE;
408 /* Ensure we only read a complete number of words. */
409 bytes_remaining = bytes_to_read & 3;
411 words = bytes_to_read >> 2;
413 status = drvdata->config->get_configuration(drvdata,
416 /* If we didn't read correctly, then bail out. */
418 free_page((unsigned long)kbuf);
422 /* If we fail to return the data to the user, then bail out. */
423 if (copy_to_user(buf, kbuf, bytes_to_read)) {
424 free_page((unsigned long)kbuf);
428 memcpy(drvdata->read_buffer,
431 drvdata->read_buffer_in_use = bytes_remaining;
432 free_page((unsigned long)kbuf);
434 status = bytes_to_read;
436 mutex_unlock(&drvdata->sem);
441 hwicap_write(struct file *file, const char __user *buf,
442 size_t count, loff_t *ppos)
444 struct hwicap_drvdata *drvdata = file->private_data;
446 ssize_t left = count;
451 status = mutex_lock_interruptible(&drvdata->sem);
455 left += drvdata->write_buffer_in_use;
457 /* Only write multiples of 4 bytes. */
463 kbuf = (u32 *) __get_free_page(GFP_KERNEL);
470 /* only write multiples of 4 bytes, so there might */
471 /* be as many as 3 bytes left (at the end). */
478 if (drvdata->write_buffer_in_use) {
479 memcpy(kbuf, drvdata->write_buffer,
480 drvdata->write_buffer_in_use);
482 (((char *)kbuf) + drvdata->write_buffer_in_use),
484 len - (drvdata->write_buffer_in_use))) {
485 free_page((unsigned long)kbuf);
490 if (copy_from_user(kbuf, buf + written, len)) {
491 free_page((unsigned long)kbuf);
497 status = drvdata->config->set_configuration(drvdata,
501 free_page((unsigned long)kbuf);
505 if (drvdata->write_buffer_in_use) {
506 len -= drvdata->write_buffer_in_use;
507 left -= drvdata->write_buffer_in_use;
508 drvdata->write_buffer_in_use = 0;
513 if ((left > 0) && (left < 4)) {
514 if (!copy_from_user(drvdata->write_buffer,
515 buf + written, left)) {
516 drvdata->write_buffer_in_use = left;
522 free_page((unsigned long)kbuf);
525 mutex_unlock(&drvdata->sem);
529 static int hwicap_open(struct inode *inode, struct file *file)
531 struct hwicap_drvdata *drvdata;
534 mutex_lock(&hwicap_mutex);
535 drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);
537 status = mutex_lock_interruptible(&drvdata->sem);
541 if (drvdata->is_open) {
546 status = hwicap_initialize_hwicap(drvdata);
548 dev_err(drvdata->dev, "Failed to open file");
552 file->private_data = drvdata;
553 drvdata->write_buffer_in_use = 0;
554 drvdata->read_buffer_in_use = 0;
555 drvdata->is_open = 1;
558 mutex_unlock(&drvdata->sem);
560 mutex_unlock(&hwicap_mutex);
564 static int hwicap_release(struct inode *inode, struct file *file)
566 struct hwicap_drvdata *drvdata = file->private_data;
570 mutex_lock(&drvdata->sem);
572 if (drvdata->write_buffer_in_use) {
573 /* Flush write buffer. */
574 for (i = drvdata->write_buffer_in_use; i < 4; i++)
575 drvdata->write_buffer[i] = 0;
577 status = drvdata->config->set_configuration(drvdata,
578 (u32 *) drvdata->write_buffer, 1);
583 status = hwicap_command_desync(drvdata);
588 drvdata->is_open = 0;
589 mutex_unlock(&drvdata->sem);
593 static const struct file_operations hwicap_fops = {
594 .owner = THIS_MODULE,
595 .write = hwicap_write,
598 .release = hwicap_release,
599 .llseek = noop_llseek,
602 static int hwicap_setup(struct device *dev, int id,
603 const struct resource *regs_res,
604 const struct hwicap_driver_config *config,
605 const struct config_registers *config_regs)
608 struct hwicap_drvdata *drvdata = NULL;
611 dev_info(dev, "Xilinx icap port driver\n");
613 mutex_lock(&icap_sem);
616 for (id = 0; id < HWICAP_DEVICES; id++)
617 if (!probed_devices[id])
620 if (id < 0 || id >= HWICAP_DEVICES) {
621 mutex_unlock(&icap_sem);
622 dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
625 if (probed_devices[id]) {
626 mutex_unlock(&icap_sem);
627 dev_err(dev, "cannot assign to %s%i; it is already in use\n",
632 probed_devices[id] = 1;
633 mutex_unlock(&icap_sem);
635 devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);
637 drvdata = kzalloc(sizeof(struct hwicap_drvdata), GFP_KERNEL);
642 dev_set_drvdata(dev, (void *)drvdata);
645 dev_err(dev, "Couldn't get registers resource\n");
650 drvdata->mem_start = regs_res->start;
651 drvdata->mem_end = regs_res->end;
652 drvdata->mem_size = resource_size(regs_res);
654 if (!request_mem_region(drvdata->mem_start,
655 drvdata->mem_size, DRIVER_NAME)) {
656 dev_err(dev, "Couldn't lock memory region at %Lx\n",
657 (unsigned long long) regs_res->start);
662 drvdata->devt = devt;
664 drvdata->base_address = ioremap(drvdata->mem_start, drvdata->mem_size);
665 if (!drvdata->base_address) {
666 dev_err(dev, "ioremap() failed\n");
671 drvdata->config = config;
672 drvdata->config_regs = config_regs;
674 mutex_init(&drvdata->sem);
675 drvdata->is_open = 0;
677 dev_info(dev, "ioremap %llx to %p with size %llx\n",
678 (unsigned long long) drvdata->mem_start,
679 drvdata->base_address,
680 (unsigned long long) drvdata->mem_size);
682 cdev_init(&drvdata->cdev, &hwicap_fops);
683 drvdata->cdev.owner = THIS_MODULE;
684 retval = cdev_add(&drvdata->cdev, devt, 1);
686 dev_err(dev, "cdev_add() failed\n");
690 device_create(icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
691 return 0; /* success */
694 iounmap(drvdata->base_address);
697 release_mem_region(regs_res->start, drvdata->mem_size);
703 mutex_lock(&icap_sem);
704 probed_devices[id] = 0;
705 mutex_unlock(&icap_sem);
710 static struct hwicap_driver_config buffer_icap_config = {
711 .get_configuration = buffer_icap_get_configuration,
712 .set_configuration = buffer_icap_set_configuration,
713 .get_status = buffer_icap_get_status,
714 .reset = buffer_icap_reset,
717 static struct hwicap_driver_config fifo_icap_config = {
718 .get_configuration = fifo_icap_get_configuration,
719 .set_configuration = fifo_icap_set_configuration,
720 .get_status = fifo_icap_get_status,
721 .reset = fifo_icap_reset,
724 static int hwicap_remove(struct device *dev)
726 struct hwicap_drvdata *drvdata;
728 drvdata = dev_get_drvdata(dev);
733 device_destroy(icap_class, drvdata->devt);
734 cdev_del(&drvdata->cdev);
735 iounmap(drvdata->base_address);
736 release_mem_region(drvdata->mem_start, drvdata->mem_size);
739 mutex_lock(&icap_sem);
740 probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
741 mutex_unlock(&icap_sem);
742 return 0; /* success */
746 static int hwicap_of_probe(struct platform_device *op,
747 const struct hwicap_driver_config *config)
750 const unsigned int *id;
753 const struct config_registers *regs;
756 rc = of_address_to_resource(op->dev.of_node, 0, &res);
758 dev_err(&op->dev, "invalid address\n");
762 id = of_get_property(op->dev.of_node, "port-number", NULL);
764 /* It's most likely that we're using V4, if the family is not
767 regs = &v4_config_registers;
768 family = of_get_property(op->dev.of_node, "xlnx,family", NULL);
771 if (!strcmp(family, "virtex2p"))
772 regs = &v2_config_registers;
773 else if (!strcmp(family, "virtex4"))
774 regs = &v4_config_registers;
775 else if (!strcmp(family, "virtex5"))
776 regs = &v5_config_registers;
777 else if (!strcmp(family, "virtex6"))
778 regs = &v6_config_registers;
780 return hwicap_setup(&op->dev, id ? *id : -1, &res, config,
784 static inline int hwicap_of_probe(struct platform_device *op,
785 const struct hwicap_driver_config *config)
789 #endif /* CONFIG_OF */
791 static const struct of_device_id hwicap_of_match[];
792 static int hwicap_drv_probe(struct platform_device *pdev)
794 const struct of_device_id *match;
795 struct resource *res;
796 const struct config_registers *regs;
799 match = of_match_device(hwicap_of_match, &pdev->dev);
801 return hwicap_of_probe(pdev, match->data);
803 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
807 /* It's most likely that we're using V4, if the family is not
810 regs = &v4_config_registers;
811 family = pdev->dev.platform_data;
814 if (!strcmp(family, "virtex2p"))
815 regs = &v2_config_registers;
816 else if (!strcmp(family, "virtex4"))
817 regs = &v4_config_registers;
818 else if (!strcmp(family, "virtex5"))
819 regs = &v5_config_registers;
820 else if (!strcmp(family, "virtex6"))
821 regs = &v6_config_registers;
824 return hwicap_setup(&pdev->dev, pdev->id, res,
825 &buffer_icap_config, regs);
828 static int hwicap_drv_remove(struct platform_device *pdev)
830 return hwicap_remove(&pdev->dev);
834 /* Match table for device tree binding */
835 static const struct of_device_id hwicap_of_match[] = {
836 { .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
837 { .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
840 MODULE_DEVICE_TABLE(of, hwicap_of_match);
842 #define hwicap_of_match NULL
845 static struct platform_driver hwicap_platform_driver = {
846 .probe = hwicap_drv_probe,
847 .remove = hwicap_drv_remove,
850 .of_match_table = hwicap_of_match,
854 static int __init hwicap_module_init(void)
859 icap_class = class_create(THIS_MODULE, "xilinx_config");
860 mutex_init(&icap_sem);
862 devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
863 retval = register_chrdev_region(devt,
869 retval = platform_driver_register(&hwicap_platform_driver);
876 unregister_chrdev_region(devt, HWICAP_DEVICES);
881 static void __exit hwicap_module_cleanup(void)
883 dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
885 class_destroy(icap_class);
887 platform_driver_unregister(&hwicap_platform_driver);
889 unregister_chrdev_region(devt, HWICAP_DEVICES);
892 module_init(hwicap_module_init);
893 module_exit(hwicap_module_cleanup);
895 MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
896 MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
897 MODULE_LICENSE("GPL");