Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP clkctrl clock support
4 *
5 * Copyright (C) 2017 Texas Instruments, Inc.
6 *
7 * Tero Kristo <t-kristo@ti.com>
8 */
9
10#include <linux/clk-provider.h>
11#include <linux/slab.h>
12#include <linux/of.h>
13#include <linux/of_address.h>
14#include <linux/clk/ti.h>
15#include <linux/delay.h>
16#include <linux/string_helpers.h>
17#include <linux/timekeeping.h>
18#include "clock.h"
19
20#define NO_IDLEST 0
21
22#define OMAP4_MODULEMODE_MASK 0x3
23
24#define MODULEMODE_HWCTRL 0x1
25#define MODULEMODE_SWCTRL 0x2
26
27#define OMAP4_IDLEST_MASK (0x3 << 16)
28#define OMAP4_IDLEST_SHIFT 16
29
30#define OMAP4_STBYST_MASK BIT(18)
31#define OMAP4_STBYST_SHIFT 18
32
33#define CLKCTRL_IDLEST_FUNCTIONAL 0x0
34#define CLKCTRL_IDLEST_INTERFACE_IDLE 0x2
35#define CLKCTRL_IDLEST_DISABLED 0x3
36
37/* These timeouts are in us */
38#define OMAP4_MAX_MODULE_READY_TIME 2000
39#define OMAP4_MAX_MODULE_DISABLE_TIME 5000
40
41static bool _early_timeout = true;
42
43struct omap_clkctrl_provider {
44 void __iomem *base;
45 struct list_head clocks;
46 char *clkdm_name;
47};
48
49struct omap_clkctrl_clk {
50 struct clk_hw *clk;
51 u16 reg_offset;
52 int bit_offset;
53 struct list_head node;
54};
55
56union omap4_timeout {
57 u32 cycles;
58 ktime_t start;
59};
60
61static const struct omap_clkctrl_data default_clkctrl_data[] __initconst = {
62 { 0 },
63};
64
65static u32 _omap4_idlest(u32 val)
66{
67 val &= OMAP4_IDLEST_MASK;
68 val >>= OMAP4_IDLEST_SHIFT;
69
70 return val;
71}
72
73static bool _omap4_is_idle(u32 val)
74{
75 val = _omap4_idlest(val);
76
77 return val == CLKCTRL_IDLEST_DISABLED;
78}
79
80static bool _omap4_is_ready(u32 val)
81{
82 val = _omap4_idlest(val);
83
84 return val == CLKCTRL_IDLEST_FUNCTIONAL ||
85 val == CLKCTRL_IDLEST_INTERFACE_IDLE;
86}
87
88static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
89{
90 /*
91 * There are two special cases where ktime_to_ns() can't be
92 * used to track the timeouts. First one is during early boot
93 * when the timers haven't been initialized yet. The second
94 * one is during suspend-resume cycle while timekeeping is
95 * being suspended / resumed. Clocksource for the system
96 * can be from a timer that requires pm_runtime access, which
97 * will eventually bring us here with timekeeping_suspended,
98 * during both suspend entry and resume paths. This happens
99 * at least on am43xx platform. Account for flakeyness
100 * with udelay() by multiplying the timeout value by 2.
101 */
102 if (unlikely(_early_timeout || timekeeping_suspended)) {
103 if (time->cycles++ < timeout) {
104 udelay(1 * 2);
105 return false;
106 }
107 } else {
108 if (!ktime_to_ns(time->start)) {
109 time->start = ktime_get();
110 return false;
111 }
112
113 if (ktime_us_delta(ktime_get(), time->start) < timeout) {
114 cpu_relax();
115 return false;
116 }
117 }
118
119 return true;
120}
121
122static int __init _omap4_disable_early_timeout(void)
123{
124 _early_timeout = false;
125
126 return 0;
127}
128arch_initcall(_omap4_disable_early_timeout);
129
130static int _omap4_clkctrl_clk_enable(struct clk_hw *hw)
131{
132 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
133 u32 val;
134 int ret;
135 union omap4_timeout timeout = { 0 };
136
137 if (clk->clkdm) {
138 ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
139 if (ret) {
140 WARN(1,
141 "%s: could not enable %s's clockdomain %s: %d\n",
142 __func__, clk_hw_get_name(hw),
143 clk->clkdm_name, ret);
144 return ret;
145 }
146 }
147
148 if (!clk->enable_bit)
149 return 0;
150
151 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
152
153 val &= ~OMAP4_MODULEMODE_MASK;
154 val |= clk->enable_bit;
155
156 ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
157
158 if (test_bit(NO_IDLEST, &clk->flags))
159 return 0;
160
161 /* Wait until module is enabled */
162 while (!_omap4_is_ready(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
163 if (_omap4_is_timeout(&timeout, OMAP4_MAX_MODULE_READY_TIME)) {
164 pr_err("%s: failed to enable\n", clk_hw_get_name(hw));
165 return -EBUSY;
166 }
167 }
168
169 return 0;
170}
171
172static void _omap4_clkctrl_clk_disable(struct clk_hw *hw)
173{
174 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
175 u32 val;
176 union omap4_timeout timeout = { 0 };
177
178 if (!clk->enable_bit)
179 goto exit;
180
181 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
182
183 val &= ~OMAP4_MODULEMODE_MASK;
184
185 ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
186
187 if (test_bit(NO_IDLEST, &clk->flags))
188 goto exit;
189
190 /* Wait until module is disabled */
191 while (!_omap4_is_idle(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
192 if (_omap4_is_timeout(&timeout,
193 OMAP4_MAX_MODULE_DISABLE_TIME)) {
194 pr_err("%s: failed to disable\n", clk_hw_get_name(hw));
195 break;
196 }
197 }
198
199exit:
200 if (clk->clkdm)
201 ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
202}
203
204static int _omap4_clkctrl_clk_is_enabled(struct clk_hw *hw)
205{
206 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
207 u32 val;
208
209 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
210
211 if (val & clk->enable_bit)
212 return 1;
213
214 return 0;
215}
216
217static const struct clk_ops omap4_clkctrl_clk_ops = {
218 .enable = _omap4_clkctrl_clk_enable,
219 .disable = _omap4_clkctrl_clk_disable,
220 .is_enabled = _omap4_clkctrl_clk_is_enabled,
221 .init = omap2_init_clk_clkdm,
222};
223
224static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
225 void *data)
226{
227 struct omap_clkctrl_provider *provider = data;
228 struct omap_clkctrl_clk *entry = NULL, *iter;
229
230 if (clkspec->args_count != 2)
231 return ERR_PTR(-EINVAL);
232
233 pr_debug("%s: looking for %x:%x\n", __func__,
234 clkspec->args[0], clkspec->args[1]);
235
236 list_for_each_entry(iter, &provider->clocks, node) {
237 if (iter->reg_offset == clkspec->args[0] &&
238 iter->bit_offset == clkspec->args[1]) {
239 entry = iter;
240 break;
241 }
242 }
243
244 if (!entry)
245 return ERR_PTR(-EINVAL);
246
247 return entry->clk;
248}
249
250/* Get clkctrl clock base name based on clkctrl_name or dts node */
251static const char * __init clkctrl_get_clock_name(struct device_node *np,
252 const char *clkctrl_name,
253 int offset, int index,
254 bool legacy_naming)
255{
256 char *clock_name;
257
258 /* l4per-clkctrl:1234:0 style naming based on clkctrl_name */
259 if (clkctrl_name && !legacy_naming) {
260 clock_name = kasprintf(GFP_KERNEL, "%s-clkctrl:%04x:%d",
261 clkctrl_name, offset, index);
262 if (!clock_name)
263 return NULL;
264
265 strreplace(clock_name, '_', '-');
266
267 return clock_name;
268 }
269
270 /* l4per:1234:0 old style naming based on clkctrl_name */
271 if (clkctrl_name)
272 return kasprintf(GFP_KERNEL, "%s_cm:clk:%04x:%d",
273 clkctrl_name, offset, index);
274
275 /* l4per_cm:1234:0 old style naming based on parent node name */
276 if (legacy_naming)
277 return kasprintf(GFP_KERNEL, "%pOFn:clk:%04x:%d",
278 np->parent, offset, index);
279
280 /* l4per-clkctrl:1234:0 style naming based on node name */
281 return kasprintf(GFP_KERNEL, "%pOFn:%04x:%d", np, offset, index);
282}
283
284static int __init
285_ti_clkctrl_clk_register(struct omap_clkctrl_provider *provider,
286 struct device_node *node, struct clk_hw *clk_hw,
287 u16 offset, u8 bit, const char * const *parents,
288 int num_parents, const struct clk_ops *ops,
289 const char *clkctrl_name)
290{
291 struct clk_init_data init = { NULL };
292 struct clk *clk;
293 struct omap_clkctrl_clk *clkctrl_clk;
294 int ret = 0;
295
296 init.name = clkctrl_get_clock_name(node, clkctrl_name, offset, bit,
297 ti_clk_get_features()->flags &
298 TI_CLK_CLKCTRL_COMPAT);
299
300 clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
301 if (!init.name || !clkctrl_clk) {
302 ret = -ENOMEM;
303 goto cleanup;
304 }
305
306 clk_hw->init = &init;
307 init.parent_names = parents;
308 init.num_parents = num_parents;
309 init.ops = ops;
310 init.flags = 0;
311
312 clk = of_ti_clk_register(node, clk_hw, init.name);
313 if (IS_ERR_OR_NULL(clk)) {
314 ret = -EINVAL;
315 goto cleanup;
316 }
317
318 clkctrl_clk->reg_offset = offset;
319 clkctrl_clk->bit_offset = bit;
320 clkctrl_clk->clk = clk_hw;
321
322 list_add(&clkctrl_clk->node, &provider->clocks);
323
324 return 0;
325
326cleanup:
327 kfree(init.name);
328 kfree(clkctrl_clk);
329 return ret;
330}
331
332static void __init
333_ti_clkctrl_setup_gate(struct omap_clkctrl_provider *provider,
334 struct device_node *node, u16 offset,
335 const struct omap_clkctrl_bit_data *data,
336 void __iomem *reg, const char *clkctrl_name)
337{
338 struct clk_hw_omap *clk_hw;
339
340 clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
341 if (!clk_hw)
342 return;
343
344 clk_hw->enable_bit = data->bit;
345 clk_hw->enable_reg.ptr = reg;
346
347 if (_ti_clkctrl_clk_register(provider, node, &clk_hw->hw, offset,
348 data->bit, data->parents, 1,
349 &omap_gate_clk_ops, clkctrl_name))
350 kfree(clk_hw);
351}
352
353static void __init
354_ti_clkctrl_setup_mux(struct omap_clkctrl_provider *provider,
355 struct device_node *node, u16 offset,
356 const struct omap_clkctrl_bit_data *data,
357 void __iomem *reg, const char *clkctrl_name)
358{
359 struct clk_omap_mux *mux;
360 int num_parents = 0;
361 const char * const *pname;
362
363 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
364 if (!mux)
365 return;
366
367 pname = data->parents;
368 while (*pname) {
369 num_parents++;
370 pname++;
371 }
372
373 mux->mask = num_parents;
374 if (!(mux->flags & CLK_MUX_INDEX_ONE))
375 mux->mask--;
376
377 mux->mask = (1 << fls(mux->mask)) - 1;
378
379 mux->shift = data->bit;
380 mux->reg.ptr = reg;
381
382 if (_ti_clkctrl_clk_register(provider, node, &mux->hw, offset,
383 data->bit, data->parents, num_parents,
384 &ti_clk_mux_ops, clkctrl_name))
385 kfree(mux);
386}
387
388static void __init
389_ti_clkctrl_setup_div(struct omap_clkctrl_provider *provider,
390 struct device_node *node, u16 offset,
391 const struct omap_clkctrl_bit_data *data,
392 void __iomem *reg, const char *clkctrl_name)
393{
394 struct clk_omap_divider *div;
395 const struct omap_clkctrl_div_data *div_data = data->data;
396 u8 div_flags = 0;
397
398 div = kzalloc(sizeof(*div), GFP_KERNEL);
399 if (!div)
400 return;
401
402 div->reg.ptr = reg;
403 div->shift = data->bit;
404 div->flags = div_data->flags;
405
406 if (div->flags & CLK_DIVIDER_POWER_OF_TWO)
407 div_flags |= CLKF_INDEX_POWER_OF_TWO;
408
409 if (ti_clk_parse_divider_data((int *)div_data->dividers, 0,
410 div_data->max_div, div_flags,
411 div)) {
412 pr_err("%s: Data parsing for %pOF:%04x:%d failed\n", __func__,
413 node, offset, data->bit);
414 kfree(div);
415 return;
416 }
417
418 if (_ti_clkctrl_clk_register(provider, node, &div->hw, offset,
419 data->bit, data->parents, 1,
420 &ti_clk_divider_ops, clkctrl_name))
421 kfree(div);
422}
423
424static void __init
425_ti_clkctrl_setup_subclks(struct omap_clkctrl_provider *provider,
426 struct device_node *node,
427 const struct omap_clkctrl_reg_data *data,
428 void __iomem *reg, const char *clkctrl_name)
429{
430 const struct omap_clkctrl_bit_data *bits = data->bit_data;
431
432 if (!bits)
433 return;
434
435 while (bits->bit) {
436 switch (bits->type) {
437 case TI_CLK_GATE:
438 _ti_clkctrl_setup_gate(provider, node, data->offset,
439 bits, reg, clkctrl_name);
440 break;
441
442 case TI_CLK_DIVIDER:
443 _ti_clkctrl_setup_div(provider, node, data->offset,
444 bits, reg, clkctrl_name);
445 break;
446
447 case TI_CLK_MUX:
448 _ti_clkctrl_setup_mux(provider, node, data->offset,
449 bits, reg, clkctrl_name);
450 break;
451
452 default:
453 pr_err("%s: bad subclk type: %d\n", __func__,
454 bits->type);
455 return;
456 }
457 bits++;
458 }
459}
460
461static void __init _clkctrl_add_provider(void *data,
462 struct device_node *np)
463{
464 of_clk_add_hw_provider(np, _ti_omap4_clkctrl_xlate, data);
465}
466
467/*
468 * Get clock name based on "clock-output-names" property or the
469 * compatible property for clkctrl.
470 */
471static const char * __init clkctrl_get_name(struct device_node *np)
472{
473 struct property *prop;
474 const int prefix_len = 11;
475 const char *compat;
476 const char *output;
477 const char *end;
478 char *name;
479
480 if (!of_property_read_string_index(np, "clock-output-names", 0,
481 &output)) {
482 int len;
483
484 len = strlen(output);
485 end = strstr(output, "_clkctrl");
486 if (end)
487 len -= strlen(end);
488 name = kstrndup(output, len, GFP_KERNEL);
489
490 return name;
491 }
492
493 of_property_for_each_string(np, "compatible", prop, compat) {
494 if (!strncmp("ti,clkctrl-", compat, prefix_len)) {
495 end = compat + prefix_len;
496 /* Two letter minimum name length for l3, l4 etc */
497 if (strnlen(end, 16) < 2)
498 continue;
499 name = kstrdup_and_replace(end, '-', '_', GFP_KERNEL);
500 if (!name)
501 continue;
502
503 return name;
504 }
505 }
506
507 return NULL;
508}
509
510static void __init _ti_omap4_clkctrl_setup(struct device_node *node)
511{
512 struct omap_clkctrl_provider *provider;
513 const struct omap_clkctrl_data *data = default_clkctrl_data;
514 const struct omap_clkctrl_reg_data *reg_data;
515 struct clk_init_data init = { NULL };
516 struct clk_hw_omap *hw;
517 struct clk *clk;
518 struct omap_clkctrl_clk *clkctrl_clk = NULL;
519 bool legacy_naming;
520 const char *clkctrl_name;
521 u32 addr;
522 int ret;
523 char *c;
524 u16 soc_mask = 0;
525 struct resource res;
526
527 of_address_to_resource(node, 0, &res);
528 addr = (u32)res.start;
529
530#ifdef CONFIG_ARCH_OMAP4
531 if (of_machine_is_compatible("ti,omap4"))
532 data = omap4_clkctrl_data;
533#endif
534#ifdef CONFIG_SOC_OMAP5
535 if (of_machine_is_compatible("ti,omap5"))
536 data = omap5_clkctrl_data;
537#endif
538#ifdef CONFIG_SOC_DRA7XX
539 if (of_machine_is_compatible("ti,dra7"))
540 data = dra7_clkctrl_data;
541 if (of_machine_is_compatible("ti,dra72"))
542 soc_mask = CLKF_SOC_DRA72;
543 if (of_machine_is_compatible("ti,dra74"))
544 soc_mask = CLKF_SOC_DRA74;
545 if (of_machine_is_compatible("ti,dra76"))
546 soc_mask = CLKF_SOC_DRA76;
547#endif
548#ifdef CONFIG_SOC_AM33XX
549 if (of_machine_is_compatible("ti,am33xx"))
550 data = am3_clkctrl_data;
551#endif
552#ifdef CONFIG_SOC_AM43XX
553 if (of_machine_is_compatible("ti,am4372"))
554 data = am4_clkctrl_data;
555
556 if (of_machine_is_compatible("ti,am438x"))
557 data = am438x_clkctrl_data;
558#endif
559#ifdef CONFIG_SOC_TI81XX
560 if (of_machine_is_compatible("ti,dm814"))
561 data = dm814_clkctrl_data;
562
563 if (of_machine_is_compatible("ti,dm816"))
564 data = dm816_clkctrl_data;
565#endif
566
567 if (ti_clk_get_features()->flags & TI_CLK_DEVICE_TYPE_GP)
568 soc_mask |= CLKF_SOC_NONSEC;
569
570 while (data->addr) {
571 if (addr == data->addr)
572 break;
573
574 data++;
575 }
576
577 if (!data->addr) {
578 pr_err("%pOF not found from clkctrl data.\n", node);
579 return;
580 }
581
582 provider = kzalloc(sizeof(*provider), GFP_KERNEL);
583 if (!provider)
584 return;
585
586 provider->base = of_iomap(node, 0);
587
588 legacy_naming = ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT;
589 clkctrl_name = clkctrl_get_name(node);
590 if (clkctrl_name) {
591 provider->clkdm_name = kasprintf(GFP_KERNEL,
592 "%s_clkdm", clkctrl_name);
593 if (!provider->clkdm_name) {
594 kfree(provider);
595 return;
596 }
597 goto clkdm_found;
598 }
599
600 /*
601 * The code below can be removed when all clkctrl nodes use domain
602 * specific compatible property and standard clock node naming
603 */
604 if (legacy_naming) {
605 provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFnxxx", node->parent);
606 if (!provider->clkdm_name) {
607 kfree(provider);
608 return;
609 }
610
611 /*
612 * Create default clkdm name, replace _cm from end of parent
613 * node name with _clkdm
614 */
615 provider->clkdm_name[strlen(provider->clkdm_name) - 2] = 0;
616 } else {
617 provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFn", node);
618 if (!provider->clkdm_name) {
619 kfree(provider);
620 return;
621 }
622
623 /*
624 * Create default clkdm name, replace _clkctrl from end of
625 * node name with _clkdm
626 */
627 provider->clkdm_name[strlen(provider->clkdm_name) - 7] = 0;
628 }
629
630 strcat(provider->clkdm_name, "clkdm");
631
632 /* Replace any dash from the clkdm name with underscore */
633 c = provider->clkdm_name;
634
635 while (*c) {
636 if (*c == '-')
637 *c = '_';
638 c++;
639 }
640clkdm_found:
641 INIT_LIST_HEAD(&provider->clocks);
642
643 /* Generate clocks */
644 reg_data = data->regs;
645
646 while (reg_data->parent) {
647 if ((reg_data->flags & CLKF_SOC_MASK) &&
648 (reg_data->flags & soc_mask) == 0) {
649 reg_data++;
650 continue;
651 }
652
653 hw = kzalloc(sizeof(*hw), GFP_KERNEL);
654 if (!hw)
655 return;
656
657 hw->enable_reg.ptr = provider->base + reg_data->offset;
658
659 _ti_clkctrl_setup_subclks(provider, node, reg_data,
660 hw->enable_reg.ptr, clkctrl_name);
661
662 if (reg_data->flags & CLKF_SW_SUP)
663 hw->enable_bit = MODULEMODE_SWCTRL;
664 if (reg_data->flags & CLKF_HW_SUP)
665 hw->enable_bit = MODULEMODE_HWCTRL;
666 if (reg_data->flags & CLKF_NO_IDLEST)
667 set_bit(NO_IDLEST, &hw->flags);
668
669 if (reg_data->clkdm_name)
670 hw->clkdm_name = reg_data->clkdm_name;
671 else
672 hw->clkdm_name = provider->clkdm_name;
673
674 init.parent_names = ®_data->parent;
675 init.num_parents = 1;
676 init.flags = 0;
677 if (reg_data->flags & CLKF_SET_RATE_PARENT)
678 init.flags |= CLK_SET_RATE_PARENT;
679
680 init.name = clkctrl_get_clock_name(node, clkctrl_name,
681 reg_data->offset, 0,
682 legacy_naming);
683 if (!init.name)
684 goto cleanup;
685
686 clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
687 if (!clkctrl_clk)
688 goto cleanup;
689
690 init.ops = &omap4_clkctrl_clk_ops;
691 hw->hw.init = &init;
692
693 clk = of_ti_clk_register_omap_hw(node, &hw->hw, init.name);
694 if (IS_ERR_OR_NULL(clk))
695 goto cleanup;
696
697 clkctrl_clk->reg_offset = reg_data->offset;
698 clkctrl_clk->clk = &hw->hw;
699
700 list_add(&clkctrl_clk->node, &provider->clocks);
701
702 reg_data++;
703 }
704
705 ret = of_clk_add_hw_provider(node, _ti_omap4_clkctrl_xlate, provider);
706 if (ret == -EPROBE_DEFER)
707 ti_clk_retry_init(node, provider, _clkctrl_add_provider);
708
709 kfree(clkctrl_name);
710
711 return;
712
713cleanup:
714 kfree(hw);
715 kfree(init.name);
716 kfree(clkctrl_name);
717 kfree(clkctrl_clk);
718}
719CLK_OF_DECLARE(ti_omap4_clkctrl_clock, "ti,clkctrl",
720 _ti_omap4_clkctrl_setup);
721
722/**
723 * ti_clk_is_in_standby - Check if clkctrl clock is in standby or not
724 * @clk: clock to check standby status for
725 *
726 * Finds whether the provided clock is in standby mode or not. Returns
727 * true if the provided clock is a clkctrl type clock and it is in standby,
728 * false otherwise.
729 */
730bool ti_clk_is_in_standby(struct clk *clk)
731{
732 struct clk_hw *hw;
733 struct clk_hw_omap *hwclk;
734 u32 val;
735
736 hw = __clk_get_hw(clk);
737
738 if (!omap2_clk_is_hw_omap(hw))
739 return false;
740
741 hwclk = to_clk_hw_omap(hw);
742
743 val = ti_clk_ll_ops->clk_readl(&hwclk->enable_reg);
744
745 if (val & OMAP4_STBYST_MASK)
746 return true;
747
748 return false;
749}
750EXPORT_SYMBOL_GPL(ti_clk_is_in_standby);
1/*
2 * OMAP clkctrl clock support
3 *
4 * Copyright (C) 2017 Texas Instruments, Inc.
5 *
6 * Tero Kristo <t-kristo@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/clk-provider.h>
19#include <linux/slab.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22#include <linux/clk/ti.h>
23#include <linux/delay.h>
24#include <linux/timekeeping.h>
25#include "clock.h"
26
27#define NO_IDLEST 0
28
29#define OMAP4_MODULEMODE_MASK 0x3
30
31#define MODULEMODE_HWCTRL 0x1
32#define MODULEMODE_SWCTRL 0x2
33
34#define OMAP4_IDLEST_MASK (0x3 << 16)
35#define OMAP4_IDLEST_SHIFT 16
36
37#define OMAP4_STBYST_MASK BIT(18)
38#define OMAP4_STBYST_SHIFT 18
39
40#define CLKCTRL_IDLEST_FUNCTIONAL 0x0
41#define CLKCTRL_IDLEST_INTERFACE_IDLE 0x2
42#define CLKCTRL_IDLEST_DISABLED 0x3
43
44/* These timeouts are in us */
45#define OMAP4_MAX_MODULE_READY_TIME 2000
46#define OMAP4_MAX_MODULE_DISABLE_TIME 5000
47
48static bool _early_timeout = true;
49
50struct omap_clkctrl_provider {
51 void __iomem *base;
52 struct list_head clocks;
53 char *clkdm_name;
54};
55
56struct omap_clkctrl_clk {
57 struct clk_hw *clk;
58 u16 reg_offset;
59 int bit_offset;
60 struct list_head node;
61};
62
63union omap4_timeout {
64 u32 cycles;
65 ktime_t start;
66};
67
68static const struct omap_clkctrl_data default_clkctrl_data[] __initconst = {
69 { 0 },
70};
71
72static u32 _omap4_idlest(u32 val)
73{
74 val &= OMAP4_IDLEST_MASK;
75 val >>= OMAP4_IDLEST_SHIFT;
76
77 return val;
78}
79
80static bool _omap4_is_idle(u32 val)
81{
82 val = _omap4_idlest(val);
83
84 return val == CLKCTRL_IDLEST_DISABLED;
85}
86
87static bool _omap4_is_ready(u32 val)
88{
89 val = _omap4_idlest(val);
90
91 return val == CLKCTRL_IDLEST_FUNCTIONAL ||
92 val == CLKCTRL_IDLEST_INTERFACE_IDLE;
93}
94
95static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
96{
97 /*
98 * There are two special cases where ktime_to_ns() can't be
99 * used to track the timeouts. First one is during early boot
100 * when the timers haven't been initialized yet. The second
101 * one is during suspend-resume cycle while timekeeping is
102 * being suspended / resumed. Clocksource for the system
103 * can be from a timer that requires pm_runtime access, which
104 * will eventually bring us here with timekeeping_suspended,
105 * during both suspend entry and resume paths. This happens
106 * at least on am43xx platform. Account for flakeyness
107 * with udelay() by multiplying the timeout value by 2.
108 */
109 if (unlikely(_early_timeout || timekeeping_suspended)) {
110 if (time->cycles++ < timeout) {
111 udelay(1 * 2);
112 return false;
113 }
114 } else {
115 if (!ktime_to_ns(time->start)) {
116 time->start = ktime_get();
117 return false;
118 }
119
120 if (ktime_us_delta(ktime_get(), time->start) < timeout) {
121 cpu_relax();
122 return false;
123 }
124 }
125
126 return true;
127}
128
129static int __init _omap4_disable_early_timeout(void)
130{
131 _early_timeout = false;
132
133 return 0;
134}
135arch_initcall(_omap4_disable_early_timeout);
136
137static int _omap4_clkctrl_clk_enable(struct clk_hw *hw)
138{
139 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
140 u32 val;
141 int ret;
142 union omap4_timeout timeout = { 0 };
143
144 if (clk->clkdm) {
145 ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
146 if (ret) {
147 WARN(1,
148 "%s: could not enable %s's clockdomain %s: %d\n",
149 __func__, clk_hw_get_name(hw),
150 clk->clkdm_name, ret);
151 return ret;
152 }
153 }
154
155 if (!clk->enable_bit)
156 return 0;
157
158 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
159
160 val &= ~OMAP4_MODULEMODE_MASK;
161 val |= clk->enable_bit;
162
163 ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
164
165 if (test_bit(NO_IDLEST, &clk->flags))
166 return 0;
167
168 /* Wait until module is enabled */
169 while (!_omap4_is_ready(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
170 if (_omap4_is_timeout(&timeout, OMAP4_MAX_MODULE_READY_TIME)) {
171 pr_err("%s: failed to enable\n", clk_hw_get_name(hw));
172 return -EBUSY;
173 }
174 }
175
176 return 0;
177}
178
179static void _omap4_clkctrl_clk_disable(struct clk_hw *hw)
180{
181 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
182 u32 val;
183 union omap4_timeout timeout = { 0 };
184
185 if (!clk->enable_bit)
186 goto exit;
187
188 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
189
190 val &= ~OMAP4_MODULEMODE_MASK;
191
192 ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
193
194 if (test_bit(NO_IDLEST, &clk->flags))
195 goto exit;
196
197 /* Wait until module is disabled */
198 while (!_omap4_is_idle(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
199 if (_omap4_is_timeout(&timeout,
200 OMAP4_MAX_MODULE_DISABLE_TIME)) {
201 pr_err("%s: failed to disable\n", clk_hw_get_name(hw));
202 break;
203 }
204 }
205
206exit:
207 if (clk->clkdm)
208 ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
209}
210
211static int _omap4_clkctrl_clk_is_enabled(struct clk_hw *hw)
212{
213 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
214 u32 val;
215
216 val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
217
218 if (val & clk->enable_bit)
219 return 1;
220
221 return 0;
222}
223
224static const struct clk_ops omap4_clkctrl_clk_ops = {
225 .enable = _omap4_clkctrl_clk_enable,
226 .disable = _omap4_clkctrl_clk_disable,
227 .is_enabled = _omap4_clkctrl_clk_is_enabled,
228 .init = omap2_init_clk_clkdm,
229};
230
231static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
232 void *data)
233{
234 struct omap_clkctrl_provider *provider = data;
235 struct omap_clkctrl_clk *entry;
236 bool found = false;
237
238 if (clkspec->args_count != 2)
239 return ERR_PTR(-EINVAL);
240
241 pr_debug("%s: looking for %x:%x\n", __func__,
242 clkspec->args[0], clkspec->args[1]);
243
244 list_for_each_entry(entry, &provider->clocks, node) {
245 if (entry->reg_offset == clkspec->args[0] &&
246 entry->bit_offset == clkspec->args[1]) {
247 found = true;
248 break;
249 }
250 }
251
252 if (!found)
253 return ERR_PTR(-EINVAL);
254
255 return entry->clk;
256}
257
258/* Get clkctrl clock base name based on clkctrl_name or dts node */
259static const char * __init clkctrl_get_clock_name(struct device_node *np,
260 const char *clkctrl_name,
261 int offset, int index,
262 bool legacy_naming)
263{
264 char *clock_name;
265
266 /* l4per-clkctrl:1234:0 style naming based on clkctrl_name */
267 if (clkctrl_name && !legacy_naming) {
268 clock_name = kasprintf(GFP_KERNEL, "%s-clkctrl:%04x:%d",
269 clkctrl_name, offset, index);
270 strreplace(clock_name, '_', '-');
271
272 return clock_name;
273 }
274
275 /* l4per:1234:0 old style naming based on clkctrl_name */
276 if (clkctrl_name)
277 return kasprintf(GFP_KERNEL, "%s_cm:clk:%04x:%d",
278 clkctrl_name, offset, index);
279
280 /* l4per_cm:1234:0 old style naming based on parent node name */
281 if (legacy_naming)
282 return kasprintf(GFP_KERNEL, "%pOFn:clk:%04x:%d",
283 np->parent, offset, index);
284
285 /* l4per-clkctrl:1234:0 style naming based on node name */
286 return kasprintf(GFP_KERNEL, "%pOFn:%04x:%d", np, offset, index);
287}
288
289static int __init
290_ti_clkctrl_clk_register(struct omap_clkctrl_provider *provider,
291 struct device_node *node, struct clk_hw *clk_hw,
292 u16 offset, u8 bit, const char * const *parents,
293 int num_parents, const struct clk_ops *ops,
294 const char *clkctrl_name)
295{
296 struct clk_init_data init = { NULL };
297 struct clk *clk;
298 struct omap_clkctrl_clk *clkctrl_clk;
299 int ret = 0;
300
301 init.name = clkctrl_get_clock_name(node, clkctrl_name, offset, bit,
302 ti_clk_get_features()->flags &
303 TI_CLK_CLKCTRL_COMPAT);
304
305 clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
306 if (!init.name || !clkctrl_clk) {
307 ret = -ENOMEM;
308 goto cleanup;
309 }
310
311 clk_hw->init = &init;
312 init.parent_names = parents;
313 init.num_parents = num_parents;
314 init.ops = ops;
315 init.flags = 0;
316
317 clk = ti_clk_register(NULL, clk_hw, init.name);
318 if (IS_ERR_OR_NULL(clk)) {
319 ret = -EINVAL;
320 goto cleanup;
321 }
322
323 clkctrl_clk->reg_offset = offset;
324 clkctrl_clk->bit_offset = bit;
325 clkctrl_clk->clk = clk_hw;
326
327 list_add(&clkctrl_clk->node, &provider->clocks);
328
329 return 0;
330
331cleanup:
332 kfree(init.name);
333 kfree(clkctrl_clk);
334 return ret;
335}
336
337static void __init
338_ti_clkctrl_setup_gate(struct omap_clkctrl_provider *provider,
339 struct device_node *node, u16 offset,
340 const struct omap_clkctrl_bit_data *data,
341 void __iomem *reg, const char *clkctrl_name)
342{
343 struct clk_hw_omap *clk_hw;
344
345 clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
346 if (!clk_hw)
347 return;
348
349 clk_hw->enable_bit = data->bit;
350 clk_hw->enable_reg.ptr = reg;
351
352 if (_ti_clkctrl_clk_register(provider, node, &clk_hw->hw, offset,
353 data->bit, data->parents, 1,
354 &omap_gate_clk_ops, clkctrl_name))
355 kfree(clk_hw);
356}
357
358static void __init
359_ti_clkctrl_setup_mux(struct omap_clkctrl_provider *provider,
360 struct device_node *node, u16 offset,
361 const struct omap_clkctrl_bit_data *data,
362 void __iomem *reg, const char *clkctrl_name)
363{
364 struct clk_omap_mux *mux;
365 int num_parents = 0;
366 const char * const *pname;
367
368 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
369 if (!mux)
370 return;
371
372 pname = data->parents;
373 while (*pname) {
374 num_parents++;
375 pname++;
376 }
377
378 mux->mask = num_parents;
379 if (!(mux->flags & CLK_MUX_INDEX_ONE))
380 mux->mask--;
381
382 mux->mask = (1 << fls(mux->mask)) - 1;
383
384 mux->shift = data->bit;
385 mux->reg.ptr = reg;
386
387 if (_ti_clkctrl_clk_register(provider, node, &mux->hw, offset,
388 data->bit, data->parents, num_parents,
389 &ti_clk_mux_ops, clkctrl_name))
390 kfree(mux);
391}
392
393static void __init
394_ti_clkctrl_setup_div(struct omap_clkctrl_provider *provider,
395 struct device_node *node, u16 offset,
396 const struct omap_clkctrl_bit_data *data,
397 void __iomem *reg, const char *clkctrl_name)
398{
399 struct clk_omap_divider *div;
400 const struct omap_clkctrl_div_data *div_data = data->data;
401 u8 div_flags = 0;
402
403 div = kzalloc(sizeof(*div), GFP_KERNEL);
404 if (!div)
405 return;
406
407 div->reg.ptr = reg;
408 div->shift = data->bit;
409 div->flags = div_data->flags;
410
411 if (div->flags & CLK_DIVIDER_POWER_OF_TWO)
412 div_flags |= CLKF_INDEX_POWER_OF_TWO;
413
414 if (ti_clk_parse_divider_data((int *)div_data->dividers, 0,
415 div_data->max_div, div_flags,
416 div)) {
417 pr_err("%s: Data parsing for %pOF:%04x:%d failed\n", __func__,
418 node, offset, data->bit);
419 kfree(div);
420 return;
421 }
422
423 if (_ti_clkctrl_clk_register(provider, node, &div->hw, offset,
424 data->bit, data->parents, 1,
425 &ti_clk_divider_ops, clkctrl_name))
426 kfree(div);
427}
428
429static void __init
430_ti_clkctrl_setup_subclks(struct omap_clkctrl_provider *provider,
431 struct device_node *node,
432 const struct omap_clkctrl_reg_data *data,
433 void __iomem *reg, const char *clkctrl_name)
434{
435 const struct omap_clkctrl_bit_data *bits = data->bit_data;
436
437 if (!bits)
438 return;
439
440 while (bits->bit) {
441 switch (bits->type) {
442 case TI_CLK_GATE:
443 _ti_clkctrl_setup_gate(provider, node, data->offset,
444 bits, reg, clkctrl_name);
445 break;
446
447 case TI_CLK_DIVIDER:
448 _ti_clkctrl_setup_div(provider, node, data->offset,
449 bits, reg, clkctrl_name);
450 break;
451
452 case TI_CLK_MUX:
453 _ti_clkctrl_setup_mux(provider, node, data->offset,
454 bits, reg, clkctrl_name);
455 break;
456
457 default:
458 pr_err("%s: bad subclk type: %d\n", __func__,
459 bits->type);
460 return;
461 }
462 bits++;
463 }
464}
465
466static void __init _clkctrl_add_provider(void *data,
467 struct device_node *np)
468{
469 of_clk_add_hw_provider(np, _ti_omap4_clkctrl_xlate, data);
470}
471
472/* Get clock name based on compatible string for clkctrl */
473static char * __init clkctrl_get_name(struct device_node *np)
474{
475 struct property *prop;
476 const int prefix_len = 11;
477 const char *compat;
478 char *name;
479
480 of_property_for_each_string(np, "compatible", prop, compat) {
481 if (!strncmp("ti,clkctrl-", compat, prefix_len)) {
482 /* Two letter minimum name length for l3, l4 etc */
483 if (strnlen(compat + prefix_len, 16) < 2)
484 continue;
485 name = kasprintf(GFP_KERNEL, "%s", compat + prefix_len);
486 if (!name)
487 continue;
488 strreplace(name, '-', '_');
489
490 return name;
491 }
492 }
493
494 return NULL;
495}
496
497static void __init _ti_omap4_clkctrl_setup(struct device_node *node)
498{
499 struct omap_clkctrl_provider *provider;
500 const struct omap_clkctrl_data *data = default_clkctrl_data;
501 const struct omap_clkctrl_reg_data *reg_data;
502 struct clk_init_data init = { NULL };
503 struct clk_hw_omap *hw;
504 struct clk *clk;
505 struct omap_clkctrl_clk *clkctrl_clk = NULL;
506 const __be32 *addrp;
507 bool legacy_naming;
508 char *clkctrl_name;
509 u32 addr;
510 int ret;
511 char *c;
512 u16 soc_mask = 0;
513
514 if (!(ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT) &&
515 of_node_name_eq(node, "clk"))
516 ti_clk_features.flags |= TI_CLK_CLKCTRL_COMPAT;
517
518 addrp = of_get_address(node, 0, NULL, NULL);
519 addr = (u32)of_translate_address(node, addrp);
520
521#ifdef CONFIG_ARCH_OMAP4
522 if (of_machine_is_compatible("ti,omap4"))
523 data = omap4_clkctrl_data;
524#endif
525#ifdef CONFIG_SOC_OMAP5
526 if (of_machine_is_compatible("ti,omap5"))
527 data = omap5_clkctrl_data;
528#endif
529#ifdef CONFIG_SOC_DRA7XX
530 if (of_machine_is_compatible("ti,dra7")) {
531 if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
532 data = dra7_clkctrl_compat_data;
533 else
534 data = dra7_clkctrl_data;
535 }
536
537 if (of_machine_is_compatible("ti,dra72"))
538 soc_mask = CLKF_SOC_DRA72;
539 if (of_machine_is_compatible("ti,dra74"))
540 soc_mask = CLKF_SOC_DRA74;
541 if (of_machine_is_compatible("ti,dra76"))
542 soc_mask = CLKF_SOC_DRA76;
543#endif
544#ifdef CONFIG_SOC_AM33XX
545 if (of_machine_is_compatible("ti,am33xx")) {
546 if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
547 data = am3_clkctrl_compat_data;
548 else
549 data = am3_clkctrl_data;
550 }
551#endif
552#ifdef CONFIG_SOC_AM43XX
553 if (of_machine_is_compatible("ti,am4372")) {
554 if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
555 data = am4_clkctrl_compat_data;
556 else
557 data = am4_clkctrl_data;
558 }
559
560 if (of_machine_is_compatible("ti,am438x")) {
561 if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
562 data = am438x_clkctrl_compat_data;
563 else
564 data = am438x_clkctrl_data;
565 }
566#endif
567#ifdef CONFIG_SOC_TI81XX
568 if (of_machine_is_compatible("ti,dm814"))
569 data = dm814_clkctrl_data;
570
571 if (of_machine_is_compatible("ti,dm816"))
572 data = dm816_clkctrl_data;
573#endif
574
575 if (ti_clk_get_features()->flags & TI_CLK_DEVICE_TYPE_GP)
576 soc_mask |= CLKF_SOC_NONSEC;
577
578 while (data->addr) {
579 if (addr == data->addr)
580 break;
581
582 data++;
583 }
584
585 if (!data->addr) {
586 pr_err("%pOF not found from clkctrl data.\n", node);
587 return;
588 }
589
590 provider = kzalloc(sizeof(*provider), GFP_KERNEL);
591 if (!provider)
592 return;
593
594 provider->base = of_iomap(node, 0);
595
596 legacy_naming = ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT;
597 clkctrl_name = clkctrl_get_name(node);
598 if (clkctrl_name) {
599 provider->clkdm_name = kasprintf(GFP_KERNEL,
600 "%s_clkdm", clkctrl_name);
601 goto clkdm_found;
602 }
603
604 /*
605 * The code below can be removed when all clkctrl nodes use domain
606 * specific compatible proprerty and standard clock node naming
607 */
608 if (legacy_naming) {
609 provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFnxxx", node->parent);
610 if (!provider->clkdm_name) {
611 kfree(provider);
612 return;
613 }
614
615 /*
616 * Create default clkdm name, replace _cm from end of parent
617 * node name with _clkdm
618 */
619 provider->clkdm_name[strlen(provider->clkdm_name) - 2] = 0;
620 } else {
621 provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFn", node);
622 if (!provider->clkdm_name) {
623 kfree(provider);
624 return;
625 }
626
627 /*
628 * Create default clkdm name, replace _clkctrl from end of
629 * node name with _clkdm
630 */
631 provider->clkdm_name[strlen(provider->clkdm_name) - 7] = 0;
632 }
633
634 strcat(provider->clkdm_name, "clkdm");
635
636 /* Replace any dash from the clkdm name with underscore */
637 c = provider->clkdm_name;
638
639 while (*c) {
640 if (*c == '-')
641 *c = '_';
642 c++;
643 }
644clkdm_found:
645 INIT_LIST_HEAD(&provider->clocks);
646
647 /* Generate clocks */
648 reg_data = data->regs;
649
650 while (reg_data->parent) {
651 if ((reg_data->flags & CLKF_SOC_MASK) &&
652 (reg_data->flags & soc_mask) == 0) {
653 reg_data++;
654 continue;
655 }
656
657 hw = kzalloc(sizeof(*hw), GFP_KERNEL);
658 if (!hw)
659 return;
660
661 hw->enable_reg.ptr = provider->base + reg_data->offset;
662
663 _ti_clkctrl_setup_subclks(provider, node, reg_data,
664 hw->enable_reg.ptr, clkctrl_name);
665
666 if (reg_data->flags & CLKF_SW_SUP)
667 hw->enable_bit = MODULEMODE_SWCTRL;
668 if (reg_data->flags & CLKF_HW_SUP)
669 hw->enable_bit = MODULEMODE_HWCTRL;
670 if (reg_data->flags & CLKF_NO_IDLEST)
671 set_bit(NO_IDLEST, &hw->flags);
672
673 if (reg_data->clkdm_name)
674 hw->clkdm_name = reg_data->clkdm_name;
675 else
676 hw->clkdm_name = provider->clkdm_name;
677
678 init.parent_names = ®_data->parent;
679 init.num_parents = 1;
680 init.flags = 0;
681 if (reg_data->flags & CLKF_SET_RATE_PARENT)
682 init.flags |= CLK_SET_RATE_PARENT;
683
684 init.name = clkctrl_get_clock_name(node, clkctrl_name,
685 reg_data->offset, 0,
686 legacy_naming);
687 if (!init.name)
688 goto cleanup;
689
690 clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
691 if (!clkctrl_clk)
692 goto cleanup;
693
694 init.ops = &omap4_clkctrl_clk_ops;
695 hw->hw.init = &init;
696
697 clk = ti_clk_register_omap_hw(NULL, &hw->hw, init.name);
698 if (IS_ERR_OR_NULL(clk))
699 goto cleanup;
700
701 clkctrl_clk->reg_offset = reg_data->offset;
702 clkctrl_clk->clk = &hw->hw;
703
704 list_add(&clkctrl_clk->node, &provider->clocks);
705
706 reg_data++;
707 }
708
709 ret = of_clk_add_hw_provider(node, _ti_omap4_clkctrl_xlate, provider);
710 if (ret == -EPROBE_DEFER)
711 ti_clk_retry_init(node, provider, _clkctrl_add_provider);
712
713 kfree(clkctrl_name);
714
715 return;
716
717cleanup:
718 kfree(hw);
719 kfree(init.name);
720 kfree(clkctrl_name);
721 kfree(clkctrl_clk);
722}
723CLK_OF_DECLARE(ti_omap4_clkctrl_clock, "ti,clkctrl",
724 _ti_omap4_clkctrl_setup);
725
726/**
727 * ti_clk_is_in_standby - Check if clkctrl clock is in standby or not
728 * @clk: clock to check standby status for
729 *
730 * Finds whether the provided clock is in standby mode or not. Returns
731 * true if the provided clock is a clkctrl type clock and it is in standby,
732 * false otherwise.
733 */
734bool ti_clk_is_in_standby(struct clk *clk)
735{
736 struct clk_hw *hw;
737 struct clk_hw_omap *hwclk;
738 u32 val;
739
740 hw = __clk_get_hw(clk);
741
742 if (!omap2_clk_is_hw_omap(hw))
743 return false;
744
745 hwclk = to_clk_hw_omap(hw);
746
747 val = ti_clk_ll_ops->clk_readl(&hwclk->enable_reg);
748
749 if (val & OMAP4_STBYST_MASK)
750 return true;
751
752 return false;
753}
754EXPORT_SYMBOL_GPL(ti_clk_is_in_standby);