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
)
149 volatile struct rtlx_info
**p
;
150 struct rtlx_channel
*chan
;
151 enum rtlx_state state
;
154 if (index
>= RTLX_CHANNELS
) {
155 printk(KERN_DEBUG
"rtlx_open index out of range\n");
159 if (atomic_inc_return(&channel_wqs
[index
].in_open
) > 1) {
160 printk(KERN_DEBUG
"rtlx_open channel %d already opened\n",
167 if( (p
= vpe_get_shared(RTLX_TARG_VPE
)) == NULL
) {
169 __wait_event_interruptible(channel_wqs
[index
].lx_queue
,
170 (p
= vpe_get_shared(RTLX_TARG_VPE
)),
175 printk(KERN_DEBUG
"No SP program loaded, and device "
176 "opened with O_NONBLOCK\n");
184 __wait_event_interruptible(channel_wqs
[index
].lx_queue
,
190 printk(" *vpe_get_shared is NULL. "
191 "Has an SP program been loaded?\n");
197 if ((unsigned int)*p
< KSEG0
) {
198 printk(KERN_WARNING
"vpe_get_shared returned an invalid pointer "
199 "maybe an error code %d\n", (int)*p
);
204 if ((ret
= rtlx_init(*p
)) < 0)
208 chan
= &rtlx
->channel
[index
];
210 state
= xchg(&chan
->lx_state
, RTLX_STATE_OPENED
);
211 if (state
== RTLX_STATE_OPENED
) {
218 atomic_dec(&channel_wqs
[index
].in_open
);
225 int rtlx_release(int index
)
227 rtlx
->channel
[index
].lx_state
= RTLX_STATE_UNUSED
;
231 unsigned int rtlx_read_poll(int index
, int can_sleep
)
233 struct rtlx_channel
*chan
;
238 chan
= &rtlx
->channel
[index
];
240 /* data available to read? */
241 if (chan
->lx_read
== chan
->lx_write
) {
245 __wait_event_interruptible(channel_wqs
[index
].lx_queue
,
246 chan
->lx_read
!= chan
->lx_write
|| sp_stopping
,
257 return (chan
->lx_write
+ chan
->buffer_size
- chan
->lx_read
)
261 static inline int write_spacefree(int read
, int write
, int size
)
265 * Never fill the buffer completely, so indexes are always
266 * equal if empty and only empty, or !equal if data available
271 return ((read
+ size
- write
) % size
) - 1;
274 unsigned int rtlx_write_poll(int index
)
276 struct rtlx_channel
*chan
= &rtlx
->channel
[index
];
277 return write_spacefree(chan
->rt_read
, chan
->rt_write
, chan
->buffer_size
);
280 static inline void copy_to(void *dst
, void *src
, size_t count
, int user
)
283 copy_to_user(dst
, src
, count
);
285 memcpy(dst
, src
, count
);
288 static inline void copy_from(void *dst
, void *src
, size_t count
, int user
)
291 copy_from_user(dst
, src
, count
);
293 memcpy(dst
, src
, count
);
296 ssize_t
rtlx_read(int index
, void *buff
, size_t count
, int user
)
299 struct rtlx_channel
*lx
;
304 lx
= &rtlx
->channel
[index
];
306 /* find out how much in total */
308 (size_t)(lx
->lx_write
+ lx
->buffer_size
- lx
->lx_read
)
311 /* then how much from the read pointer onwards */
312 fl
= min( count
, (size_t)lx
->buffer_size
- lx
->lx_read
);
314 copy_to(buff
, &lx
->lx_buffer
[lx
->lx_read
], fl
, user
);
316 /* and if there is anything left at the beginning of the buffer */
318 copy_to (buff
+ fl
, lx
->lx_buffer
, count
- fl
, user
);
320 /* update the index */
321 lx
->lx_read
+= count
;
322 lx
->lx_read
%= lx
->buffer_size
;
327 ssize_t
rtlx_write(int index
, void *buffer
, size_t count
, int user
)
329 struct rtlx_channel
*rt
;
335 rt
= &rtlx
->channel
[index
];
337 /* total number of bytes to copy */
339 (size_t)write_spacefree(rt
->rt_read
, rt
->rt_write
,
342 /* first bit from write pointer to the end of the buffer, or count */
343 fl
= min(count
, (size_t) rt
->buffer_size
- rt
->rt_write
);
345 copy_from (&rt
->rt_buffer
[rt
->rt_write
], buffer
, fl
, user
);
347 /* if there's any left copy to the beginning of the buffer */
349 copy_from (rt
->rt_buffer
, buffer
+ fl
, count
- fl
, user
);
351 rt
->rt_write
+= count
;
352 rt
->rt_write
%= rt
->buffer_size
;
358 static int file_open(struct inode
*inode
, struct file
*filp
)
360 int minor
= iminor(inode
);
362 return rtlx_open(minor
, (filp
->f_flags
& O_NONBLOCK
) ? 0 : 1);
365 static int file_release(struct inode
*inode
, struct file
*filp
)
367 int minor
= iminor(inode
);
369 return rtlx_release(minor
);
372 static unsigned int file_poll(struct file
*file
, poll_table
* wait
)
375 unsigned int mask
= 0;
377 minor
= iminor(file
->f_path
.dentry
->d_inode
);
379 poll_wait(file
, &channel_wqs
[minor
].rt_queue
, wait
);
380 poll_wait(file
, &channel_wqs
[minor
].lx_queue
, wait
);
385 /* data available to read? */
386 if (rtlx_read_poll(minor
, 0))
387 mask
|= POLLIN
| POLLRDNORM
;
390 if (rtlx_write_poll(minor
))
391 mask
|= POLLOUT
| POLLWRNORM
;
396 static ssize_t
file_read(struct file
*file
, char __user
* buffer
, size_t count
,
399 int minor
= iminor(file
->f_path
.dentry
->d_inode
);
401 /* data available? */
402 if (!rtlx_read_poll(minor
, (file
->f_flags
& O_NONBLOCK
) ? 0 : 1)) {
403 return 0; // -EAGAIN makes cat whinge
406 return rtlx_read(minor
, buffer
, count
, 1);
409 static ssize_t
file_write(struct file
*file
, const char __user
* buffer
,
410 size_t count
, loff_t
* ppos
)
413 struct rtlx_channel
*rt
;
415 minor
= iminor(file
->f_path
.dentry
->d_inode
);
416 rt
= &rtlx
->channel
[minor
];
418 /* any space left... */
419 if (!rtlx_write_poll(minor
)) {
422 if (file
->f_flags
& O_NONBLOCK
)
425 __wait_event_interruptible(channel_wqs
[minor
].rt_queue
,
426 rtlx_write_poll(minor
),
432 return rtlx_write(minor
, (void *)buffer
, count
, 1);
435 static const struct file_operations rtlx_fops
= {
436 .owner
= THIS_MODULE
,
438 .release
= file_release
,
444 static struct irqaction rtlx_irq
= {
445 .handler
= rtlx_interrupt
,
446 .flags
= IRQF_DISABLED
,
450 static int rtlx_irq_num
= MIPS_CPU_IRQ_BASE
+ MIPS_CPU_RTLX_IRQ
;
452 static char register_chrdev_failed
[] __initdata
=
453 KERN_ERR
"rtlx_module_init: unable to register device\n";
455 static int rtlx_module_init(void)
460 major
= register_chrdev(0, module_name
, &rtlx_fops
);
462 printk(register_chrdev_failed
);
466 /* initialise the wait queues */
467 for (i
= 0; i
< RTLX_CHANNELS
; i
++) {
468 init_waitqueue_head(&channel_wqs
[i
].rt_queue
);
469 init_waitqueue_head(&channel_wqs
[i
].lx_queue
);
470 atomic_set(&channel_wqs
[i
].in_open
, 0);
472 dev
= device_create(mt_class
, NULL
, MKDEV(major
, i
),
473 "%s%d", module_name
, i
);
480 /* set up notifiers */
481 notify
.start
= starting
;
482 notify
.stop
= stopping
;
483 vpe_notify(RTLX_TARG_VPE
, ¬ify
);
486 set_vi_handler(MIPS_CPU_RTLX_IRQ
, rtlx_dispatch
);
488 rtlx_irq
.dev_id
= rtlx
;
489 setup_irq(rtlx_irq_num
, &rtlx_irq
);
494 for (i
= 0; i
< RTLX_CHANNELS
; i
++)
495 device_destroy(mt_class
, MKDEV(major
, i
));
500 static void __exit
rtlx_module_exit(void)
504 for (i
= 0; i
< RTLX_CHANNELS
; i
++)
505 device_destroy(mt_class
, MKDEV(major
, i
));
507 unregister_chrdev(major
, module_name
);
510 module_init(rtlx_module_init
);
511 module_exit(rtlx_module_exit
);
513 MODULE_DESCRIPTION("MIPS RTLX");
514 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
515 MODULE_LICENSE("GPL");