1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
|
/*
* SCI Clock driver for keystone based devices
*
* Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
* Tero Kristo <t-kristo@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/soc/ti/ti_sci_protocol.h>
#include <linux/bsearch.h>
#include <linux/list_sort.h>
#define SCI_CLK_SSC_ENABLE BIT(0)
#define SCI_CLK_ALLOW_FREQ_CHANGE BIT(1)
#define SCI_CLK_INPUT_TERMINATION BIT(2)
/**
* struct sci_clk_provider - TI SCI clock provider representation
* @sci: Handle to the System Control Interface protocol handler
* @ops: Pointer to the SCI ops to be used by the clocks
* @dev: Device pointer for the clock provider
* @clocks: Clocks array for this device
* @num_clocks: Total number of clocks for this provider
*/
struct sci_clk_provider {
const struct ti_sci_handle *sci;
const struct ti_sci_clk_ops *ops;
struct device *dev;
struct sci_clk **clocks;
int num_clocks;
};
/**
* struct sci_clk - TI SCI clock representation
* @hw: Hardware clock cookie for common clock framework
* @dev_id: Device index
* @clk_id: Clock index
* @num_parents: Number of parents for this clock
* @provider: Master clock provider
* @flags: Flags for the clock
* @node: Link for handling clocks probed via DT
* @cached_req: Cached requested freq for determine rate calls
* @cached_res: Cached result freq for determine rate calls
*/
struct sci_clk {
struct clk_hw hw;
u16 dev_id;
u32 clk_id;
u32 num_parents;
struct sci_clk_provider *provider;
u8 flags;
struct list_head node;
unsigned long cached_req;
unsigned long cached_res;
};
#define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
/**
* sci_clk_prepare - Prepare (enable) a TI SCI clock
* @hw: clock to prepare
*
* Prepares a clock to be actively used. Returns the SCI protocol status.
*/
static int sci_clk_prepare(struct clk_hw *hw)
{
struct sci_clk *clk = to_sci_clk(hw);
bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE;
bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE;
bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION;
return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id,
clk->clk_id, enable_ssc,
allow_freq_change,
input_termination);
}
/**
* sci_clk_unprepare - Un-prepares (disables) a TI SCI clock
* @hw: clock to unprepare
*
* Un-prepares a clock from active state.
*/
static void sci_clk_unprepare(struct clk_hw *hw)
{
struct sci_clk *clk = to_sci_clk(hw);
int ret;
ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id,
clk->clk_id);
if (ret)
dev_err(clk->provider->dev,
"unprepare failed for dev=%d, clk=%d, ret=%d\n",
clk->dev_id, clk->clk_id, ret);
}
/**
* sci_clk_is_prepared - Check if a TI SCI clock is prepared or not
* @hw: clock to check status for
*
* Checks if a clock is prepared (enabled) in hardware. Returns non-zero
* value if clock is enabled, zero otherwise.
*/
static int sci_clk_is_prepared(struct clk_hw *hw)
{
struct sci_clk *clk = to_sci_clk(hw);
bool req_state, current_state;
int ret;
ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id,
clk->clk_id, &req_state,
¤t_state);
if (ret) {
dev_err(clk->provider->dev,
"is_prepared failed for dev=%d, clk=%d, ret=%d\n",
clk->dev_id, clk->clk_id, ret);
return 0;
}
return req_state;
}
/**
* sci_clk_recalc_rate - Get clock rate for a TI SCI clock
* @hw: clock to get rate for
* @parent_rate: parent rate provided by common clock framework, not used
*
* Gets the current clock rate of a TI SCI clock. Returns the current
* clock rate, or zero in failure.
*/
static unsigned long sci_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct sci_clk *clk = to_sci_clk(hw);
u64 freq;
int ret;
ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id,
clk->clk_id, &freq);
if (ret) {
dev_err(clk->provider->dev,
"recalc-rate failed for dev=%d, clk=%d, ret=%d\n",
clk->dev_id, clk->clk_id, ret);
return 0;
}
return freq;
}
/**
* sci_clk_determine_rate - Determines a clock rate a clock can be set to
* @hw: clock to change rate for
* @req: requested rate configuration for the clock
*
* Determines a suitable clock rate and parent for a TI SCI clock.
* The parent handling is un-used, as generally the parent clock rates
* are not known by the kernel; instead these are internally handled
* by the firmware. Returns 0 on success, negative error value on failure.
*/
static int sci_clk_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct sci_clk *clk = to_sci_clk(hw);
int ret;
u64 new_rate;
if (clk->cached_req && clk->cached_req == req->rate) {
req->rate = clk->cached_res;
return 0;
}
ret = clk->provider->ops->get_best_match_freq(clk->provider->sci,
clk->dev_id,
clk->clk_id,
req->min_rate,
req->rate,
req->max_rate,
&new_rate);
if (ret) {
dev_err(clk->provider->dev,
"determine-rate failed for dev=%d, clk=%d, ret=%d\n",
clk->dev_id, clk->clk_id, ret);
return ret;
}
clk->cached_req = req->rate;
clk->cached_res = new_rate;
req->rate = new_rate;
return 0;
}
/**
* sci_clk_set_rate - Set rate for a TI SCI clock
* @hw: clock to change rate for
* @rate: target rate for the clock
* @parent_rate: rate of the clock parent, not used for TI SCI clocks
*
* Sets a clock frequency for a TI SCI clock. Returns the TI SCI
* protocol status.
*/
static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct sci_clk *clk = to_sci_clk(hw);
return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
clk->clk_id, rate, rate, rate);
}
/**
* sci_clk_get_parent - Get the current parent of a TI SCI clock
* @hw: clock to get parent for
*
* Returns the index of the currently selected parent for a TI SCI clock.
*/
static u8 sci_clk_get_parent(struct clk_hw *hw)
{
struct sci_clk *clk = to_sci_clk(hw);
u32 parent_id = 0;
int ret;
ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id,
clk->clk_id, (void *)&parent_id);
if (ret) {
dev_err(clk->provider->dev,
"get-parent failed for dev=%d, clk=%d, ret=%d\n",
clk->dev_id, clk->clk_id, ret);
return 0;
}
parent_id = parent_id - clk->clk_id - 1;
return (u8)parent_id;
}
/**
* sci_clk_set_parent - Set the parent of a TI SCI clock
* @hw: clock to set parent for
* @index: new parent index for the clock
*
* Sets the parent of a TI SCI clock. Return TI SCI protocol status.
*/
static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
{
struct sci_clk *clk = to_sci_clk(hw);
clk->cached_req = 0;
return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
clk->clk_id,
index + 1 + clk->clk_id);
}
static const struct clk_ops sci_clk_ops = {
.prepare = sci_clk_prepare,
.unprepare = sci_clk_unprepare,
.is_prepared = sci_clk_is_prepared,
.recalc_rate = sci_clk_recalc_rate,
.determine_rate = sci_clk_determine_rate,
.set_rate = sci_clk_set_rate,
.get_parent = sci_clk_get_parent,
.set_parent = sci_clk_set_parent,
};
/**
* _sci_clk_get - Gets a handle for an SCI clock
* @provider: Handle to SCI clock provider
* @sci_clk: Handle to the SCI clock to populate
*
* Gets a handle to an existing TI SCI hw clock, or builds a new clock
* entry and registers it with the common clock framework. Called from
* the common clock framework, when a corresponding of_clk_get call is
* executed, or recursively from itself when parsing parent clocks.
* Returns 0 on success, negative error code on failure.
*/
static int _sci_clk_build(struct sci_clk_provider *provider,
struct sci_clk *sci_clk)
{
struct clk_init_data init = { NULL };
char *name = NULL;
char **parent_names = NULL;
int i;
int ret = 0;
name = kasprintf(GFP_KERNEL, "clk:%d:%d", sci_clk->dev_id,
sci_clk->clk_id);
init.name = name;
/*
* From kernel point of view, we only care about a clocks parents,
* if it has more than 1 possible parent. In this case, it is going
* to have mux functionality. Otherwise it is going to act as a root
* clock.
*/
if (sci_clk->num_parents < 2)
sci_clk->num_parents = 0;
if (sci_clk->num_parents) {
parent_names = kcalloc(sci_clk->num_parents, sizeof(char *),
GFP_KERNEL);
if (!parent_names) {
ret = -ENOMEM;
goto err;
}
for (i = 0; i < sci_clk->num_parents; i++) {
char *parent_name;
parent_name = kasprintf(GFP_KERNEL, "clk:%d:%d",
sci_clk->dev_id,
sci_clk->clk_id + 1 + i);
if (!parent_name) {
ret = -ENOMEM;
goto err;
}
parent_names[i] = parent_name;
}
init.parent_names = (void *)parent_names;
}
init.ops = &sci_clk_ops;
init.num_parents = sci_clk->num_parents;
sci_clk->hw.init = &init;
ret = devm_clk_hw_register(provider->dev, &sci_clk->hw);
if (ret)
dev_err(provider->dev, "failed clk register with %d\n", ret);
err:
if (parent_names) {
for (i = 0; i < sci_clk->num_parents; i++)
kfree(parent_names[i]);
kfree(parent_names);
}
kfree(name);
return ret;
}
static int _cmp_sci_clk(const void *a, const void *b)
{
const struct sci_clk *ca = a;
const struct sci_clk *cb = *(struct sci_clk **)b;
if (ca->dev_id == cb->dev_id && ca->clk_id == cb->clk_id)
return 0;
if (ca->dev_id > cb->dev_id ||
(ca->dev_id == cb->dev_id && ca->clk_id > cb->clk_id))
return 1;
return -1;
}
/**
* sci_clk_get - Xlate function for getting clock handles
* @clkspec: device tree clock specifier
* @data: pointer to the clock provider
*
* Xlate function for retrieving clock TI SCI hw clock handles based on
* device tree clock specifier. Called from the common clock framework,
* when a corresponding of_clk_get call is executed. Returns a pointer
* to the TI SCI hw clock struct, or ERR_PTR value in failure.
*/
static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data)
{
struct sci_clk_provider *provider = data;
struct sci_clk **clk;
struct sci_clk key;
if (clkspec->args_count != 2)
return ERR_PTR(-EINVAL);
key.dev_id = clkspec->args[0];
key.clk_id = clkspec->args[1];
clk = bsearch(&key, provider->clocks, provider->num_clocks,
sizeof(clk), _cmp_sci_clk);
if (!clk)
return ERR_PTR(-ENODEV);
return &(*clk)->hw;
}
static int ti_sci_init_clocks(struct sci_clk_provider *p)
{
int i;
int ret;
for (i = 0; i < p->num_clocks; i++) {
ret = _sci_clk_build(p, p->clocks[i]);
if (ret)
return ret;
}
return 0;
}
static const struct of_device_id ti_sci_clk_of_match[] = {
{ .compatible = "ti,k2g-sci-clk" },
{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match);
#ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW
static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider)
{
int ret;
int num_clks = 0;
struct sci_clk **clks = NULL;
struct sci_clk **tmp_clks;
struct sci_clk *sci_clk;
int max_clks = 0;
int clk_id = 0;
int dev_id = 0;
u32 num_parents = 0;
int gap_size = 0;
struct device *dev = provider->dev;
while (1) {
ret = provider->ops->get_num_parents(provider->sci, dev_id,
clk_id,
(void *)&num_parents);
if (ret) {
gap_size++;
if (!clk_id) {
if (gap_size >= 5)
break;
dev_id++;
} else {
if (gap_size >= 2) {
dev_id++;
clk_id = 0;
gap_size = 0;
} else {
clk_id++;
}
}
continue;
}
gap_size = 0;
if (num_clks == max_clks) {
tmp_clks = devm_kmalloc_array(dev, max_clks + 64,
sizeof(sci_clk),
GFP_KERNEL);
memcpy(tmp_clks, clks, max_clks * sizeof(sci_clk));
if (max_clks)
devm_kfree(dev, clks);
max_clks += 64;
clks = tmp_clks;
}
sci_clk = devm_kzalloc(dev, sizeof(*sci_clk), GFP_KERNEL);
if (!sci_clk)
return -ENOMEM;
sci_clk->dev_id = dev_id;
sci_clk->clk_id = clk_id;
sci_clk->provider = provider;
sci_clk->num_parents = num_parents;
clks[num_clks] = sci_clk;
clk_id++;
num_clks++;
}
provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk),
GFP_KERNEL);
if (!provider->clocks)
return -ENOMEM;
memcpy(provider->clocks, clks, num_clks * sizeof(sci_clk));
provider->num_clocks = num_clks;
devm_kfree(dev, clks);
return 0;
}
#else
static int _cmp_sci_clk_list(void *priv, struct list_head *a,
struct list_head *b)
{
struct sci_clk *ca = container_of(a, struct sci_clk, node);
struct sci_clk *cb = container_of(b, struct sci_clk, node);
return _cmp_sci_clk(ca, &cb);
}
static int ti_sci_scan_clocks_from_dt(struct sci_clk_provider *provider)
{
struct device *dev = provider->dev;
struct device_node *np = NULL;
int ret;
int index;
struct of_phandle_args args;
struct list_head clks;
struct sci_clk *sci_clk, *prev;
int num_clks = 0;
int num_parents;
int clk_id;
const char * const clk_names[] = {
"clocks", "assigned-clocks", "assigned-clock-parents", NULL
};
const char * const *clk_name;
INIT_LIST_HEAD(&clks);
clk_name = clk_names;
while (*clk_name) {
np = of_find_node_with_property(np, *clk_name);
if (!np) {
clk_name++;
continue;
}
if (!of_device_is_available(np))
continue;
index = 0;
do {
ret = of_parse_phandle_with_args(np, *clk_name,
"#clock-cells", index,
&args);
if (ret)
break;
if (args.args_count == 2 && args.np == dev->of_node) {
sci_clk = devm_kzalloc(dev, sizeof(*sci_clk),
GFP_KERNEL);
if (!sci_clk)
return -ENOMEM;
sci_clk->dev_id = args.args[0];
sci_clk->clk_id = args.args[1];
sci_clk->provider = provider;
provider->ops->get_num_parents(provider->sci,
sci_clk->dev_id,
sci_clk->clk_id,
(void *)&sci_clk->num_parents);
list_add_tail(&sci_clk->node, &clks);
num_clks++;
num_parents = sci_clk->num_parents;
if (num_parents == 1)
num_parents = 0;
/*
* Linux kernel has inherent limitation
* of 255 clock parents at the moment.
* Right now, it is not expected that
* any mux clock from sci-clk driver
* would exceed that limit either, but
* the ABI basically provides that
* possibility. Print out a warning if
* this happens for any clock.
*/
if (num_parents >= 255) {
dev_warn(dev, "too many parents for dev=%d, clk=%d (%d), cropping to 255.\n",
sci_clk->dev_id,
sci_clk->clk_id, num_parents);
num_parents = 255;
}
clk_id = args.args[1] + 1;
while (num_parents--) {
sci_clk = devm_kzalloc(dev,
sizeof(*sci_clk),
GFP_KERNEL);
if (!sci_clk)
return -ENOMEM;
sci_clk->dev_id = args.args[0];
sci_clk->clk_id = clk_id++;
sci_clk->provider = provider;
list_add_tail(&sci_clk->node, &clks);
num_clks++;
}
}
index++;
} while (args.np);
}
list_sort(NULL, &clks, _cmp_sci_clk_list);
provider->clocks = devm_kmalloc_array(dev, num_clks, sizeof(sci_clk),
GFP_KERNEL);
if (!provider->clocks)
return -ENOMEM;
num_clks = 0;
prev = NULL;
list_for_each_entry(sci_clk, &clks, node) {
if (prev && prev->dev_id == sci_clk->dev_id &&
prev->clk_id == sci_clk->clk_id)
continue;
provider->clocks[num_clks++] = sci_clk;
prev = sci_clk;
}
provider->num_clocks = num_clks;
return 0;
}
#endif
/**
* ti_sci_clk_probe - Probe function for the TI SCI clock driver
* @pdev: platform device pointer to be probed
*
* Probes the TI SCI clock device. Allocates a new clock provider
* and registers this to the common clock framework. Also applies
* any required flags to the identified clocks via clock lists
* supplied from DT. Returns 0 for success, negative error value
* for failure.
*/
static int ti_sci_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct sci_clk_provider *provider;
const struct ti_sci_handle *handle;
int ret;
handle = devm_ti_sci_get_handle(dev);
if (IS_ERR(handle))
return PTR_ERR(handle);
provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
if (!provider)
return -ENOMEM;
provider->sci = handle;
provider->ops = &handle->ops.clk_ops;
provider->dev = dev;
#ifdef CONFIG_TI_SCI_CLK_PROBE_FROM_FW
ret = ti_sci_scan_clocks_from_fw(provider);
if (ret) {
dev_err(dev, "scan clocks from FW failed: %d\n", ret);
return ret;
}
#else
ret = ti_sci_scan_clocks_from_dt(provider);
if (ret) {
dev_err(dev, "scan clocks from DT failed: %d\n", ret);
return ret;
}
#endif
ret = ti_sci_init_clocks(provider);
if (ret) {
pr_err("ti-sci-init-clocks failed.\n");
return ret;
}
return of_clk_add_hw_provider(np, sci_clk_get, provider);
}
/**
* ti_sci_clk_remove - Remove TI SCI clock device
* @pdev: platform device pointer for the device to be removed
*
* Removes the TI SCI device. Unregisters the clock provider registered
* via common clock framework. Any memory allocated for the device will
* be free'd silently via the devm framework. Returns 0 always.
*/
static int ti_sci_clk_remove(struct platform_device *pdev)
{
of_clk_del_provider(pdev->dev.of_node);
return 0;
}
static struct platform_driver ti_sci_clk_driver = {
.probe = ti_sci_clk_probe,
.remove = ti_sci_clk_remove,
.driver = {
.name = "ti-sci-clk",
.of_match_table = of_match_ptr(ti_sci_clk_of_match),
},
};
module_platform_driver(ti_sci_clk_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver");
MODULE_AUTHOR("Tero Kristo");
MODULE_ALIAS("platform:ti-sci-clk");
|