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/*
2
 * Copyright (c) 2008 Pavel Rimsky
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
29
/** @addtogroup sparc64
30
 * @{
31
 */
32
/**
33
 * @file
34
 * @brief   SGCN driver.
35
 */
36
 
37
#include <arch/drivers/sgcn.h>
38
#include <arch/drivers/kbd.h>
39
#include <genarch/ofw/ofw_tree.h>
40
#include <debug.h>
41
#include <func.h>
42
#include <print.h>
43
#include <mm/page.h>
44
#include <ipc/irq.h>
45
#include <ddi/ddi.h>
46
#include <ddi/device.h>
47
#include <console/chardev.h>
48
#include <console/console.h>
49
#include <ddi/device.h>
50
#include <sysinfo/sysinfo.h>
51
#include <synch/spinlock.h>
52
 
53
/*
54
 * Physical address at which the SBBC starts. This value has been obtained
55
 * by inspecting (using Simics) memory accesses made by OBP. It is valid
56
 * for the Simics-simulated Serengeti machine. The author of this code is
57
 * not sure whether this value is valid generally.
58
 */
59
#define SBBC_START      0x63000000000
60
 
61
/* offset of SRAM within the SBBC memory */
62
#define SBBC_SRAM_OFFSET    0x900000
63
 
64
/* size (in bytes) of the physical memory area which will be mapped */
65
#define MAPPED_AREA_SIZE    (128 * 1024)
66
 
67
/* magic string contained at the beginning of SRAM */
68
#define SRAM_TOC_MAGIC      "TOCSRAM"
69
 
70
/*
71
 * Key into the SRAM table of contents which identifies the entry
72
 * describing the OBP console buffer. It is worth mentioning
73
 * that the OBP console buffer is not the only console buffer
74
 * which can be used. It is, however, used because when the kernel
75
 * is running, the OBP buffer is not used by OBP any more but OBP
76
 * has already made neccessary arangements so that the output will
77
 * be read from the OBP buffer and input will go to the OBP buffer.
78
 * Therefore HelenOS needs to make no such arrangements any more.
79
 */
80
#define CONSOLE_KEY     "OBPCONS"
81
 
82
/* magic string contained at the beginning of the console buffer */
83
#define SGCN_BUFFER_MAGIC   "CON"
84
 
85
/**
86
 * The driver is polling based, but in order to notify the userspace
87
 * of a key being pressed, we need to supply the interface with some
88
 * interrupt number. The interrupt number can be arbitrary as it it
89
 * will never be used for identifying HW interrupts, but only in
90
 * notifying the userspace.
91
 */
92
#define FICTIONAL_INR       1
93
 
94
 
95
/*
96
 * Returns a pointer to the object of a given type which is placed at the given
97
 * offset from the SRAM beginning.
98
 */
99
#define SRAM(type, offset)  ((type *) (sram_begin + (offset)))
100
 
101
/* Returns a pointer to the SRAM table of contents. */
102
#define SRAM_TOC        (SRAM(iosram_toc_t, 0))
103
 
104
/*
105
 * Returns a pointer to the object of a given type which is placed at the given
106
 * offset from the console buffer beginning.
107
 */
108
#define SGCN_BUFFER(type, offset) \
109
                ((type *) (sgcn_buffer_begin + (offset)))
110
 
111
/** Returns a pointer to the console buffer header. */
112
#define SGCN_BUFFER_HEADER  (SGCN_BUFFER(sgcn_buffer_header_t, 0))
113
 
114
/** defined in drivers/kbd.c */
115
extern kbd_type_t kbd_type;
116
 
117
/** starting address of SRAM, will be set by the init_sram_begin function */
118
static uintptr_t sram_begin;
119
 
120
/**
121
 * starting address of the SGCN buffer, will be set by the
122
 * init_sgcn_buffer_begin function
123
 */
124
static uintptr_t sgcn_buffer_begin;
125
 
126
/**
127
 * SGCN IRQ structure. So far used only for notifying the userspace of the
128
 * key being pressed, not for kernel being informed about keyboard interrupts.
129
 */
130
static irq_t sgcn_irq;
131
 
132
// TODO think of a way how to synchronize accesses to SGCN buffer between the kernel and the userspace
133
 
134
/*
135
 * Ensures that writing to the buffer and consequent update of the write pointer
136
 * are together one atomic operation.
137
 */
138
SPINLOCK_INITIALIZE(sgcn_output_lock);
139
 
140
/*
141
 * Prevents the input buffer read/write pointers from getting to inconsistent
142
 * state.
143
 */
144
SPINLOCK_INITIALIZE(sgcn_input_lock);
145
 
146
 
147
/* functions referenced from definitions of I/O operations structures */
148
static void sgcn_noop(chardev_t *);
149
static void sgcn_putchar(chardev_t *, const char);
150
static char sgcn_key_read(chardev_t *);
151
 
152
/** character device operations */
153
static chardev_operations_t sgcn_ops = {
154
    .suspend = sgcn_noop,
155
    .resume = sgcn_noop,
156
    .read = sgcn_key_read,
157
    .write = sgcn_putchar
158
};
159
 
160
/** SGCN character device */
161
chardev_t sgcn_io;
162
 
163
/**
164
 * Registers the physical area of the SRAM so that the userspace SGCN
165
 * driver can map it. Moreover, it sets some sysinfo values (SRAM address
166
 * and SRAM size).
167
 */
168
static void register_sram_parea(uintptr_t sram_begin_physical)
169
{
170
    static parea_t sram_parea;
171
    sram_parea.pbase = sram_begin_physical;
172
    sram_parea.vbase = (uintptr_t) sram_begin;
173
    sram_parea.frames = MAPPED_AREA_SIZE / FRAME_SIZE;
174
    sram_parea.cacheable = false;
175
    ddi_parea_register(&sram_parea);
176
 
177
    sysinfo_set_item_val("sram.area.size", NULL, MAPPED_AREA_SIZE);
178
    sysinfo_set_item_val("sram.address.physical", NULL,
179
        sram_begin_physical);
180
}
181
 
182
/**
183
 * Initializes the starting address of SRAM.
184
 *
185
 * The SRAM starts 0x900000 + C bytes behind the SBBC start in the
186
 * physical memory, where C is the value read from the "iosram-toc"
187
 * property of the "/chosen" OBP node. The sram_begin variable will
188
 * be set to the virtual address which maps to the SRAM physical
189
 * address.
190
 *
191
 * It also registers the physical area of SRAM and sets some sysinfo
192
 * values (SRAM address and SRAM size).
193
 */
194
static void init_sram_begin(void)
195
{
196
    ofw_tree_node_t *chosen;
197
    ofw_tree_property_t *iosram_toc;
198
    uintptr_t sram_begin_physical;
199
 
200
    chosen = ofw_tree_lookup("/chosen");
201
    if (!chosen)
202
        panic("Can't find /chosen.\n");
203
 
204
    iosram_toc = ofw_tree_getprop(chosen, "iosram-toc");
205
    if (!iosram_toc)
206
        panic("Can't find property \"iosram-toc\".\n");
207
    if (!iosram_toc->value)
208
        panic("Can't find SRAM TOC.\n");
209
 
210
    sram_begin_physical = SBBC_START + SBBC_SRAM_OFFSET
211
        + *((uint32_t *) iosram_toc->value);
212
    sram_begin = hw_map(sram_begin_physical, MAPPED_AREA_SIZE);
213
 
214
    register_sram_parea(sram_begin_physical);
215
}
216
 
217
/**
218
 * Initializes the starting address of the SGCN buffer.
219
 *
220
 * The offset of the SGCN buffer within SRAM is obtained from the
221
 * SRAM table of contents. The table of contents contains
222
 * information about several buffers, among which there is an OBP
223
 * console buffer - this one will be used as the SGCN buffer.
224
 *
225
 * This function also writes the offset of the SGCN buffer within SRAM
226
 * under the sram.buffer.offset sysinfo key.
227
 */
228
static void sgcn_buffer_begin_init(void)
229
{
230
    init_sram_begin();
231
 
232
    ASSERT(strcmp(SRAM_TOC->magic, SRAM_TOC_MAGIC) == 0);
233
 
234
    /* lookup TOC entry with the correct key */
235
    uint32_t i;
236
    for (i = 0; i < MAX_TOC_ENTRIES; i++) {
237
        if (strcmp(SRAM_TOC->keys[i].key, CONSOLE_KEY) == 0)
238
            break;
239
    }
240
    ASSERT(i < MAX_TOC_ENTRIES);
241
 
242
    sgcn_buffer_begin = sram_begin + SRAM_TOC->keys[i].offset;
243
 
244
    sysinfo_set_item_val("sram.buffer.offset", NULL,
245
        SRAM_TOC->keys[i].offset);
246
}
247
 
248
/**
249
 * Default suspend/resume operation for the input device.
250
 */
251
static void sgcn_noop(chardev_t *d)
252
{
253
}
254
 
255
/**
256
 * Writes a single character to the SGCN (circular) output buffer
257
 * and updates the output write pointer so that SGCN gets to know
258
 * that the character has been written.
259
 */
260
static void sgcn_do_putchar(const char c)
261
{
262
    uint32_t begin = SGCN_BUFFER_HEADER->out_begin;
263
    uint32_t end = SGCN_BUFFER_HEADER->out_end;
264
    uint32_t size = end - begin;
265
 
266
    /* we need pointers to volatile variables */
267
    volatile char *buf_ptr = (volatile char *)
268
        SGCN_BUFFER(char, SGCN_BUFFER_HEADER->out_wrptr);
269
    volatile uint32_t *out_wrptr_ptr = &(SGCN_BUFFER_HEADER->out_wrptr);
270
    volatile uint32_t *out_rdptr_ptr = &(SGCN_BUFFER_HEADER->out_rdptr);
271
 
272
    /*
273
     * Write the character and increment the write pointer modulo the
274
     * output buffer size. Note that if we are to rewrite a character
275
     * which has not been read by the SGCN controller yet (i.e. the output
276
     * buffer is full), we need to wait until the controller reads some more
277
     * characters. We wait actively, which means that all threads waiting
278
     * for the lock are blocked. However, this situation is
279
     *   1) rare - the output buffer is big, so filling the whole
280
     *             output buffer is improbable
281
     *   2) short-lasting - it will take the controller only a fraction
282
     *             of millisecond to pick the unread characters up
283
     *   3) not serious - the blocked threads are those that print something
284
     *             to user console, which is not a time-critical operation
285
     */
286
    uint32_t new_wrptr = (((*out_wrptr_ptr) - begin + 1) % size) + begin;
287
    while (*out_rdptr_ptr == new_wrptr)
288
        ;
289
    *buf_ptr = c;
290
    *out_wrptr_ptr = new_wrptr;
291
}
292
 
293
/**
294
 * SGCN output operation. Prints a single character to the SGCN. If the line
295
 * feed character is written ('\n'), the carriage return character ('\r') is
296
 * written straight away.
297
 */
298
static void sgcn_putchar(struct chardev * cd, const char c)
299
{
300
    spinlock_lock(&sgcn_output_lock);
301
 
302
    sgcn_do_putchar(c);
303
    if (c == '\n') {
304
        sgcn_do_putchar('\r');
305
    }
306
 
307
    spinlock_unlock(&sgcn_output_lock);
308
}
309
 
310
/**
311
 * Called when actively reading the character. Not implemented yet.
312
 */
313
static char sgcn_key_read(chardev_t *d)
314
{
315
    return (char) 0;
316
}
317
 
318
/**
319
 * The driver works in polled mode, so no interrupt should be handled by it.
320
 */
321
static irq_ownership_t sgcn_claim(void)
322
{
323
    return IRQ_DECLINE;
324
}
325
 
326
/**
327
 * The driver works in polled mode, so no interrupt should be handled by it.
328
 */
329
static void sgcn_irq_handler(irq_t *irq, void *arg, ...)
330
{
331
    panic("Not yet implemented, SGCN works in polled mode.\n");
332
}
333
 
334
/**
335
 * Grabs the input for kernel.
336
 */
337
void sgcn_grab(void)
338
{
339
    ipl_t ipl = interrupts_disable();
340
 
341
    volatile uint32_t *in_wrptr_ptr = &(SGCN_BUFFER_HEADER->in_wrptr);
342
    volatile uint32_t *in_rdptr_ptr = &(SGCN_BUFFER_HEADER->in_rdptr);
343
 
344
    /* skip all the user typed before the grab and hasn't been processed */
345
    spinlock_lock(&sgcn_input_lock);
346
    *in_rdptr_ptr = *in_wrptr_ptr;
347
    spinlock_unlock(&sgcn_input_lock);
348
 
349
    spinlock_lock(&sgcn_irq.lock);
350
    sgcn_irq.notif_cfg.notify = false;
351
    spinlock_unlock(&sgcn_irq.lock);
352
 
353
    interrupts_restore(ipl);
354
}
355
 
356
/**
357
 * Releases the input so that userspace can use it.
358
 */
359
void sgcn_release(void)
360
{
361
    ipl_t ipl = interrupts_disable();
362
    spinlock_lock(&sgcn_irq.lock);
363
    if (sgcn_irq.notif_cfg.answerbox)
364
        sgcn_irq.notif_cfg.notify = true;
365
    spinlock_unlock(&sgcn_irq.lock);
366
    interrupts_restore(ipl);
367
}
368
 
369
/**
370
 * Function regularly called by the keyboard polling thread. Finds out whether
371
 * there are some unread characters in the input queue. If so, it picks them up
372
 * and sends them to the upper layers of HelenOS.
373
 */
374
void sgcn_poll(void)
375
{
376
    uint32_t begin = SGCN_BUFFER_HEADER->in_begin;
377
    uint32_t end = SGCN_BUFFER_HEADER->in_end;
378
    uint32_t size = end - begin;
379
 
380
    spinlock_lock(&sgcn_input_lock);
381
 
382
    ipl_t ipl = interrupts_disable();
383
    spinlock_lock(&sgcn_irq.lock);
384
 
385
    /* we need pointers to volatile variables */
386
    volatile char *buf_ptr = (volatile char *)
387
        SGCN_BUFFER(char, SGCN_BUFFER_HEADER->in_rdptr);
388
    volatile uint32_t *in_wrptr_ptr = &(SGCN_BUFFER_HEADER->in_wrptr);
389
    volatile uint32_t *in_rdptr_ptr = &(SGCN_BUFFER_HEADER->in_rdptr);
390
 
391
    if (*in_rdptr_ptr != *in_wrptr_ptr) {
392
        if (sgcn_irq.notif_cfg.notify && sgcn_irq.notif_cfg.answerbox) {
393
            ipc_irq_send_notif(&sgcn_irq);
394
            spinlock_unlock(&sgcn_irq.lock);
395
            interrupts_restore(ipl);
396
            spinlock_unlock(&sgcn_input_lock);
397
            return;
398
        }
399
    }
400
 
401
    spinlock_unlock(&sgcn_irq.lock);
402
    interrupts_restore(ipl);   
403
 
404
    while (*in_rdptr_ptr != *in_wrptr_ptr) {
405
 
406
        buf_ptr = (volatile char *)
407
            SGCN_BUFFER(char, SGCN_BUFFER_HEADER->in_rdptr);
408
        char c = *buf_ptr;
409
        *in_rdptr_ptr = (((*in_rdptr_ptr) - begin + 1) % size) + begin;
410
 
411
        if (c == '\r') {
412
            c = '\n';
413
        }
414
        chardev_push_character(&sgcn_io, c);   
415
    }  
416
 
417
    spinlock_unlock(&sgcn_input_lock);
418
}
419
 
420
/**
421
 * A public function which initializes I/O from/to Serengeti console
422
 * and sets it as a default input/output.
423
 */
424
void sgcn_init(void)
425
{
426
    sgcn_buffer_begin_init();
427
 
428
    kbd_type = KBD_SGCN;
429
 
430
    devno_t devno = device_assign_devno();
431
    irq_initialize(&sgcn_irq);
432
    sgcn_irq.devno = devno;
433
    sgcn_irq.inr = FICTIONAL_INR;
434
    sgcn_irq.claim = sgcn_claim;
435
    sgcn_irq.handler = sgcn_irq_handler;
436
    irq_register(&sgcn_irq);
437
 
438
    sysinfo_set_item_val("kbd", NULL, true);
439
    sysinfo_set_item_val("kbd.type", NULL, KBD_SGCN);
440
    sysinfo_set_item_val("kbd.devno", NULL, devno);
441
    sysinfo_set_item_val("kbd.inr", NULL, FICTIONAL_INR);
442
    sysinfo_set_item_val("fb.kind", NULL, 4);
443
 
444
    chardev_initialize("sgcn_io", &sgcn_io, &sgcn_ops);
445
    stdin = &sgcn_io;
446
    stdout = &sgcn_io;
447
}
448
 
449
/** @}
450
 */