2 * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
3 * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
5 * This program is free software; you can distribute it and/or modify it
6 * under the terms of the GNU General Public License (Version 2) as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
20 #include <linux/device.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <asm/uaccess.h>
26 #include <linux/slab.h>
27 #include <linux/list.h>
28 #include <linux/vmalloc.h>
29 #include <linux/elf.h>
30 #include <linux/seq_file.h>
31 #include <linux/syscalls.h>
32 #include <linux/moduleloader.h>
33 #include <linux/interrupt.h>
34 #include <linux/poll.h>
35 #include <linux/sched.h>
36 #include <linux/wait.h>
37 #include <asm/mipsmtregs.h>
38 #include <asm/mips_mt.h>
39 #include <asm/cacheflush.h>
40 #include <asm/atomic.h>
42 #include <asm/processor.h>
43 #include <asm/system.h>
47 #define RTLX_TARG_VPE 1
49 static struct rtlx_info *rtlx;
51 static char module_name[] = "rtlx";
53 static struct chan_waitqueues {
54 wait_queue_head_t rt_queue;
55 wait_queue_head_t lx_queue;
57 } channel_wqs[RTLX_CHANNELS];
59 static struct irqaction irq;
61 static struct vpe_notifications notify;
62 static int sp_stopping = 0;
64 extern void *vpe_get_shared(int index);
66 static void rtlx_dispatch(void)
68 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
72 /* Interrupt handler may be called before rtlx_init has otherwise had
75 static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
79 for (i = 0; i < RTLX_CHANNELS; i++) {
80 wake_up(&channel_wqs[i].lx_queue);
81 wake_up(&channel_wqs[i].rt_queue);
87 static __attribute_used__ void dump_rtlx(void)
91 printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
93 for (i = 0; i < RTLX_CHANNELS; i++) {
94 struct rtlx_channel *chan = &rtlx->channel[i];
96 printk(" rt_state %d lx_state %d buffer_size %d\n",
97 chan->rt_state, chan->lx_state, chan->buffer_size);
99 printk(" rt_read %d rt_write %d\n",
100 chan->rt_read, chan->rt_write);
102 printk(" lx_read %d lx_write %d\n",
103 chan->lx_read, chan->lx_write);
105 printk(" rt_buffer <%s>\n", chan->rt_buffer);
106 printk(" lx_buffer <%s>\n", chan->lx_buffer);
110 /* call when we have the address of the shared structure from the SP side. */
111 static int rtlx_init(struct rtlx_info *rtlxi)
113 if (rtlxi->id != RTLX_ID) {
114 printk(KERN_ERR "no valid RTLX id at 0x%p 0x%x\n", rtlxi, rtlxi->id);
124 static void starting(int vpe)
129 /* force a reload of rtlx */
132 /* wake up any sleeping rtlx_open's */
133 for (i = 0; i < RTLX_CHANNELS; i++)
134 wake_up_interruptible(&channel_wqs[i].lx_queue);
137 static void stopping(int vpe)
142 for (i = 0; i < RTLX_CHANNELS; i++)
143 wake_up_interruptible(&channel_wqs[i].lx_queue);
147 int rtlx_open(int index, int can_sleep)
150 struct rtlx_channel *chan;
151 volatile struct rtlx_info **p;
153 if (index >= RTLX_CHANNELS) {
154 printk(KERN_DEBUG "rtlx_open index out of range\n");
158 if (channel_wqs[index].in_open) {
159 printk(KERN_DEBUG "rtlx_open channel %d already opened\n", index);
163 channel_wqs[index].in_open++;
166 if( (p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
168 DECLARE_WAITQUEUE(wait, current);
171 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
173 set_current_state(TASK_INTERRUPTIBLE);
174 while ((p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
176 set_current_state(TASK_INTERRUPTIBLE);
179 set_current_state(TASK_RUNNING);
180 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
184 printk( KERN_DEBUG "No SP program loaded, and device "
185 "opened with O_NONBLOCK\n");
186 channel_wqs[index].in_open = 0;
193 DECLARE_WAITQUEUE(wait, current);
196 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
198 set_current_state(TASK_INTERRUPTIBLE);
202 /* reset task state to interruptable otherwise
203 we'll whizz round here like a very fast loopy
204 thing. schedule() appears to return with state
207 If the loaded SP program, for whatever reason,
208 doesn't set up the shared structure *p will never
209 become true. So whoever connected to either /dev/rt?
210 or if it was kspd, will then take up rather a lot of
214 set_current_state(TASK_INTERRUPTIBLE);
217 set_current_state(TASK_RUNNING);
218 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
223 printk(" *vpe_get_shared is NULL. "
224 "Has an SP program been loaded?\n");
225 channel_wqs[index].in_open = 0;
230 if ((unsigned int)*p < KSEG0) {
231 printk(KERN_WARNING "vpe_get_shared returned an invalid pointer "
232 "maybe an error code %d\n", (int)*p);
233 channel_wqs[index].in_open = 0;
237 if ((ret = rtlx_init(*p)) < 0) {
238 channel_wqs[index].in_open = 0;
243 chan = &rtlx->channel[index];
245 if (chan->lx_state == RTLX_STATE_OPENED) {
246 channel_wqs[index].in_open = 0;
250 chan->lx_state = RTLX_STATE_OPENED;
251 channel_wqs[index].in_open = 0;
255 int rtlx_release(int index)
257 rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
261 unsigned int rtlx_read_poll(int index, int can_sleep)
263 struct rtlx_channel *chan;
268 chan = &rtlx->channel[index];
270 /* data available to read? */
271 if (chan->lx_read == chan->lx_write) {
273 DECLARE_WAITQUEUE(wait, current);
276 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
278 set_current_state(TASK_INTERRUPTIBLE);
279 while (chan->lx_read == chan->lx_write) {
282 set_current_state(TASK_INTERRUPTIBLE);
285 set_current_state(TASK_RUNNING);
286 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
291 set_current_state(TASK_RUNNING);
292 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
300 return (chan->lx_write + chan->buffer_size - chan->lx_read)
304 static inline int write_spacefree(int read, int write, int size)
308 * Never fill the buffer completely, so indexes are always
309 * equal if empty and only empty, or !equal if data available
314 return ((read + size - write) % size) - 1;
317 unsigned int rtlx_write_poll(int index)
319 struct rtlx_channel *chan = &rtlx->channel[index];
320 return write_spacefree(chan->rt_read, chan->rt_write, chan->buffer_size);
323 static inline void copy_to(void *dst, void *src, size_t count, int user)
326 copy_to_user(dst, src, count);
328 memcpy(dst, src, count);
331 static inline void copy_from(void *dst, void *src, size_t count, int user)
334 copy_from_user(dst, src, count);
336 memcpy(dst, src, count);
339 ssize_t rtlx_read(int index, void *buff, size_t count, int user)
342 struct rtlx_channel *lx;
347 lx = &rtlx->channel[index];
349 /* find out how much in total */
351 (size_t)(lx->lx_write + lx->buffer_size - lx->lx_read)
354 /* then how much from the read pointer onwards */
355 fl = min( count, (size_t)lx->buffer_size - lx->lx_read);
357 copy_to(buff, &lx->lx_buffer[lx->lx_read], fl, user);
359 /* and if there is anything left at the beginning of the buffer */
361 copy_to (buff + fl, lx->lx_buffer, count - fl, user);
363 /* update the index */
364 lx->lx_read += count;
365 lx->lx_read %= lx->buffer_size;
370 ssize_t rtlx_write(int index, void *buffer, size_t count, int user)
372 struct rtlx_channel *rt;
378 rt = &rtlx->channel[index];
380 /* total number of bytes to copy */
382 (size_t)write_spacefree(rt->rt_read, rt->rt_write,
385 /* first bit from write pointer to the end of the buffer, or count */
386 fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
388 copy_from (&rt->rt_buffer[rt->rt_write], buffer, fl, user);
390 /* if there's any left copy to the beginning of the buffer */
392 copy_from (rt->rt_buffer, buffer + fl, count - fl, user);
394 rt->rt_write += count;
395 rt->rt_write %= rt->buffer_size;
401 static int file_open(struct inode *inode, struct file *filp)
403 int minor = iminor(inode);
405 return rtlx_open(minor, (filp->f_flags & O_NONBLOCK) ? 0 : 1);
408 static int file_release(struct inode *inode, struct file *filp)
410 int minor = iminor(inode);
412 return rtlx_release(minor);
415 static unsigned int file_poll(struct file *file, poll_table * wait)
418 unsigned int mask = 0;
420 minor = iminor(file->f_path.dentry->d_inode);
422 poll_wait(file, &channel_wqs[minor].rt_queue, wait);
423 poll_wait(file, &channel_wqs[minor].lx_queue, wait);
428 /* data available to read? */
429 if (rtlx_read_poll(minor, 0))
430 mask |= POLLIN | POLLRDNORM;
433 if (rtlx_write_poll(minor))
434 mask |= POLLOUT | POLLWRNORM;
439 static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
442 int minor = iminor(file->f_path.dentry->d_inode);
444 /* data available? */
445 if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) {
446 return 0; // -EAGAIN makes cat whinge
449 return rtlx_read(minor, buffer, count, 1);
452 static ssize_t file_write(struct file *file, const char __user * buffer,
453 size_t count, loff_t * ppos)
456 struct rtlx_channel *rt;
457 DECLARE_WAITQUEUE(wait, current);
459 minor = iminor(file->f_path.dentry->d_inode);
460 rt = &rtlx->channel[minor];
462 /* any space left... */
463 if (!rtlx_write_poll(minor)) {
465 if (file->f_flags & O_NONBLOCK)
468 add_wait_queue(&channel_wqs[minor].rt_queue, &wait);
469 set_current_state(TASK_INTERRUPTIBLE);
471 while (!rtlx_write_poll(minor))
474 set_current_state(TASK_RUNNING);
475 remove_wait_queue(&channel_wqs[minor].rt_queue, &wait);
478 return rtlx_write(minor, (void *)buffer, count, 1);
481 static struct file_operations rtlx_fops = {
482 .owner = THIS_MODULE,
484 .release = file_release,
490 static struct irqaction rtlx_irq = {
491 .handler = rtlx_interrupt,
492 .flags = IRQF_DISABLED,
496 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
498 static char register_chrdev_failed[] __initdata =
499 KERN_ERR "rtlx_module_init: unable to register device\n";
501 static int rtlx_module_init(void)
506 major = register_chrdev(0, module_name, &rtlx_fops);
508 printk(register_chrdev_failed);
512 /* initialise the wait queues */
513 for (i = 0; i < RTLX_CHANNELS; i++) {
514 init_waitqueue_head(&channel_wqs[i].rt_queue);
515 init_waitqueue_head(&channel_wqs[i].lx_queue);
516 channel_wqs[i].in_open = 0;
518 dev = device_create(mt_class, NULL, MKDEV(major, i),
519 "%s%d", module_name, i);
526 /* set up notifiers */
527 notify.start = starting;
528 notify.stop = stopping;
529 vpe_notify(RTLX_TARG_VPE, ¬ify);
532 set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
534 rtlx_irq.dev_id = rtlx;
535 setup_irq(rtlx_irq_num, &rtlx_irq);
540 for (i = 0; i < RTLX_CHANNELS; i++)
541 device_destroy(mt_class, MKDEV(major, i));
546 static void __exit rtlx_module_exit(void)
550 for (i = 0; i < RTLX_CHANNELS; i++)
551 device_destroy(mt_class, MKDEV(major, i));
553 unregister_chrdev(major, module_name);
556 module_init(rtlx_module_init);
557 module_exit(rtlx_module_exit);
559 MODULE_DESCRIPTION("MIPS RTLX");
560 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
561 MODULE_LICENSE("GPL");