xref: /openbmc/linux/drivers/clk/ti/clkctrl.c (revision cb1aaebe)
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			0x1
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 CLKCTRL_IDLEST_FUNCTIONAL	0x0
38 #define CLKCTRL_IDLEST_INTERFACE_IDLE	0x2
39 #define CLKCTRL_IDLEST_DISABLED		0x3
40 
41 /* These timeouts are in us */
42 #define OMAP4_MAX_MODULE_READY_TIME	2000
43 #define OMAP4_MAX_MODULE_DISABLE_TIME	5000
44 
45 static bool _early_timeout = true;
46 
47 struct omap_clkctrl_provider {
48 	void __iomem *base;
49 	struct list_head clocks;
50 	char *clkdm_name;
51 };
52 
53 struct omap_clkctrl_clk {
54 	struct clk_hw *clk;
55 	u16 reg_offset;
56 	int bit_offset;
57 	struct list_head node;
58 };
59 
60 union omap4_timeout {
61 	u32 cycles;
62 	ktime_t start;
63 };
64 
65 static const struct omap_clkctrl_data default_clkctrl_data[] __initconst = {
66 	{ 0 },
67 };
68 
69 static u32 _omap4_idlest(u32 val)
70 {
71 	val &= OMAP4_IDLEST_MASK;
72 	val >>= OMAP4_IDLEST_SHIFT;
73 
74 	return val;
75 }
76 
77 static bool _omap4_is_idle(u32 val)
78 {
79 	val = _omap4_idlest(val);
80 
81 	return val == CLKCTRL_IDLEST_DISABLED;
82 }
83 
84 static bool _omap4_is_ready(u32 val)
85 {
86 	val = _omap4_idlest(val);
87 
88 	return val == CLKCTRL_IDLEST_FUNCTIONAL ||
89 	       val == CLKCTRL_IDLEST_INTERFACE_IDLE;
90 }
91 
92 static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
93 {
94 	/*
95 	 * There are two special cases where ktime_to_ns() can't be
96 	 * used to track the timeouts. First one is during early boot
97 	 * when the timers haven't been initialized yet. The second
98 	 * one is during suspend-resume cycle while timekeeping is
99 	 * being suspended / resumed. Clocksource for the system
100 	 * can be from a timer that requires pm_runtime access, which
101 	 * will eventually bring us here with timekeeping_suspended,
102 	 * during both suspend entry and resume paths. This happens
103 	 * at least on am43xx platform.
104 	 */
105 	if (unlikely(_early_timeout || timekeeping_suspended)) {
106 		if (time->cycles++ < timeout) {
107 			udelay(1);
108 			return false;
109 		}
110 	} else {
111 		if (!ktime_to_ns(time->start)) {
112 			time->start = ktime_get();
113 			return false;
114 		}
115 
116 		if (ktime_us_delta(ktime_get(), time->start) < timeout) {
117 			cpu_relax();
118 			return false;
119 		}
120 	}
121 
122 	return true;
123 }
124 
125 static int __init _omap4_disable_early_timeout(void)
126 {
127 	_early_timeout = false;
128 
129 	return 0;
130 }
131 arch_initcall(_omap4_disable_early_timeout);
132 
133 static int _omap4_clkctrl_clk_enable(struct clk_hw *hw)
134 {
135 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
136 	u32 val;
137 	int ret;
138 	union omap4_timeout timeout = { 0 };
139 
140 	if (!clk->enable_bit)
141 		return 0;
142 
143 	if (clk->clkdm) {
144 		ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
145 		if (ret) {
146 			WARN(1,
147 			     "%s: could not enable %s's clockdomain %s: %d\n",
148 			     __func__, clk_hw_get_name(hw),
149 			     clk->clkdm_name, ret);
150 			return ret;
151 		}
152 	}
153 
154 	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
155 
156 	val &= ~OMAP4_MODULEMODE_MASK;
157 	val |= clk->enable_bit;
158 
159 	ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
160 
161 	if (clk->flags & NO_IDLEST)
162 		return 0;
163 
164 	/* Wait until module is enabled */
165 	while (!_omap4_is_ready(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
166 		if (_omap4_is_timeout(&timeout, OMAP4_MAX_MODULE_READY_TIME)) {
167 			pr_err("%s: failed to enable\n", clk_hw_get_name(hw));
168 			return -EBUSY;
169 		}
170 	}
171 
172 	return 0;
173 }
174 
175 static void _omap4_clkctrl_clk_disable(struct clk_hw *hw)
176 {
177 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
178 	u32 val;
179 	union omap4_timeout timeout = { 0 };
180 
181 	if (!clk->enable_bit)
182 		return;
183 
184 	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
185 
186 	val &= ~OMAP4_MODULEMODE_MASK;
187 
188 	ti_clk_ll_ops->clk_writel(val, &clk->enable_reg);
189 
190 	if (clk->flags & NO_IDLEST)
191 		goto exit;
192 
193 	/* Wait until module is disabled */
194 	while (!_omap4_is_idle(ti_clk_ll_ops->clk_readl(&clk->enable_reg))) {
195 		if (_omap4_is_timeout(&timeout,
196 				      OMAP4_MAX_MODULE_DISABLE_TIME)) {
197 			pr_err("%s: failed to disable\n", clk_hw_get_name(hw));
198 			break;
199 		}
200 	}
201 
202 exit:
203 	if (clk->clkdm)
204 		ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
205 }
206 
207 static int _omap4_clkctrl_clk_is_enabled(struct clk_hw *hw)
208 {
209 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
210 	u32 val;
211 
212 	val = ti_clk_ll_ops->clk_readl(&clk->enable_reg);
213 
214 	if (val & clk->enable_bit)
215 		return 1;
216 
217 	return 0;
218 }
219 
220 static const struct clk_ops omap4_clkctrl_clk_ops = {
221 	.enable		= _omap4_clkctrl_clk_enable,
222 	.disable	= _omap4_clkctrl_clk_disable,
223 	.is_enabled	= _omap4_clkctrl_clk_is_enabled,
224 	.init		= omap2_init_clk_clkdm,
225 };
226 
227 static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
228 					      void *data)
229 {
230 	struct omap_clkctrl_provider *provider = data;
231 	struct omap_clkctrl_clk *entry;
232 
233 	if (clkspec->args_count != 2)
234 		return ERR_PTR(-EINVAL);
235 
236 	pr_debug("%s: looking for %x:%x\n", __func__,
237 		 clkspec->args[0], clkspec->args[1]);
238 
239 	list_for_each_entry(entry, &provider->clocks, node) {
240 		if (entry->reg_offset == clkspec->args[0] &&
241 		    entry->bit_offset == clkspec->args[1])
242 			break;
243 	}
244 
245 	if (!entry)
246 		return ERR_PTR(-EINVAL);
247 
248 	return entry->clk;
249 }
250 
251 static int __init
252 _ti_clkctrl_clk_register(struct omap_clkctrl_provider *provider,
253 			 struct device_node *node, struct clk_hw *clk_hw,
254 			 u16 offset, u8 bit, const char * const *parents,
255 			 int num_parents, const struct clk_ops *ops)
256 {
257 	struct clk_init_data init = { NULL };
258 	struct clk *clk;
259 	struct omap_clkctrl_clk *clkctrl_clk;
260 	int ret = 0;
261 
262 	if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
263 		init.name = kasprintf(GFP_KERNEL, "%pOFn:%pOFn:%04x:%d",
264 				      node->parent, node, offset,
265 				      bit);
266 	else
267 		init.name = kasprintf(GFP_KERNEL, "%pOFn:%04x:%d", node,
268 				      offset, bit);
269 	clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
270 	if (!init.name || !clkctrl_clk) {
271 		ret = -ENOMEM;
272 		goto cleanup;
273 	}
274 
275 	clk_hw->init = &init;
276 	init.parent_names = parents;
277 	init.num_parents = num_parents;
278 	init.ops = ops;
279 	init.flags = 0;
280 
281 	clk = ti_clk_register(NULL, clk_hw, init.name);
282 	if (IS_ERR_OR_NULL(clk)) {
283 		ret = -EINVAL;
284 		goto cleanup;
285 	}
286 
287 	clkctrl_clk->reg_offset = offset;
288 	clkctrl_clk->bit_offset = bit;
289 	clkctrl_clk->clk = clk_hw;
290 
291 	list_add(&clkctrl_clk->node, &provider->clocks);
292 
293 	return 0;
294 
295 cleanup:
296 	kfree(init.name);
297 	kfree(clkctrl_clk);
298 	return ret;
299 }
300 
301 static void __init
302 _ti_clkctrl_setup_gate(struct omap_clkctrl_provider *provider,
303 		       struct device_node *node, u16 offset,
304 		       const struct omap_clkctrl_bit_data *data,
305 		       void __iomem *reg)
306 {
307 	struct clk_hw_omap *clk_hw;
308 
309 	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
310 	if (!clk_hw)
311 		return;
312 
313 	clk_hw->enable_bit = data->bit;
314 	clk_hw->enable_reg.ptr = reg;
315 
316 	if (_ti_clkctrl_clk_register(provider, node, &clk_hw->hw, offset,
317 				     data->bit, data->parents, 1,
318 				     &omap_gate_clk_ops))
319 		kfree(clk_hw);
320 }
321 
322 static void __init
323 _ti_clkctrl_setup_mux(struct omap_clkctrl_provider *provider,
324 		      struct device_node *node, u16 offset,
325 		      const struct omap_clkctrl_bit_data *data,
326 		      void __iomem *reg)
327 {
328 	struct clk_omap_mux *mux;
329 	int num_parents = 0;
330 	const char * const *pname;
331 
332 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
333 	if (!mux)
334 		return;
335 
336 	pname = data->parents;
337 	while (*pname) {
338 		num_parents++;
339 		pname++;
340 	}
341 
342 	mux->mask = num_parents;
343 	if (!(mux->flags & CLK_MUX_INDEX_ONE))
344 		mux->mask--;
345 
346 	mux->mask = (1 << fls(mux->mask)) - 1;
347 
348 	mux->shift = data->bit;
349 	mux->reg.ptr = reg;
350 
351 	if (_ti_clkctrl_clk_register(provider, node, &mux->hw, offset,
352 				     data->bit, data->parents, num_parents,
353 				     &ti_clk_mux_ops))
354 		kfree(mux);
355 }
356 
357 static void __init
358 _ti_clkctrl_setup_div(struct omap_clkctrl_provider *provider,
359 		      struct device_node *node, u16 offset,
360 		      const struct omap_clkctrl_bit_data *data,
361 		      void __iomem *reg)
362 {
363 	struct clk_omap_divider *div;
364 	const struct omap_clkctrl_div_data *div_data = data->data;
365 	u8 div_flags = 0;
366 
367 	div = kzalloc(sizeof(*div), GFP_KERNEL);
368 	if (!div)
369 		return;
370 
371 	div->reg.ptr = reg;
372 	div->shift = data->bit;
373 	div->flags = div_data->flags;
374 
375 	if (div->flags & CLK_DIVIDER_POWER_OF_TWO)
376 		div_flags |= CLKF_INDEX_POWER_OF_TWO;
377 
378 	if (ti_clk_parse_divider_data((int *)div_data->dividers, 0,
379 				      div_data->max_div, div_flags,
380 				      &div->width, &div->table)) {
381 		pr_err("%s: Data parsing for %pOF:%04x:%d failed\n", __func__,
382 		       node, offset, data->bit);
383 		kfree(div);
384 		return;
385 	}
386 
387 	if (_ti_clkctrl_clk_register(provider, node, &div->hw, offset,
388 				     data->bit, data->parents, 1,
389 				     &ti_clk_divider_ops))
390 		kfree(div);
391 }
392 
393 static void __init
394 _ti_clkctrl_setup_subclks(struct omap_clkctrl_provider *provider,
395 			  struct device_node *node,
396 			  const struct omap_clkctrl_reg_data *data,
397 			  void __iomem *reg)
398 {
399 	const struct omap_clkctrl_bit_data *bits = data->bit_data;
400 
401 	if (!bits)
402 		return;
403 
404 	while (bits->bit) {
405 		switch (bits->type) {
406 		case TI_CLK_GATE:
407 			_ti_clkctrl_setup_gate(provider, node, data->offset,
408 					       bits, reg);
409 			break;
410 
411 		case TI_CLK_DIVIDER:
412 			_ti_clkctrl_setup_div(provider, node, data->offset,
413 					      bits, reg);
414 			break;
415 
416 		case TI_CLK_MUX:
417 			_ti_clkctrl_setup_mux(provider, node, data->offset,
418 					      bits, reg);
419 			break;
420 
421 		default:
422 			pr_err("%s: bad subclk type: %d\n", __func__,
423 			       bits->type);
424 			return;
425 		}
426 		bits++;
427 	}
428 }
429 
430 static void __init _clkctrl_add_provider(void *data,
431 					 struct device_node *np)
432 {
433 	of_clk_add_hw_provider(np, _ti_omap4_clkctrl_xlate, data);
434 }
435 
436 static void __init _ti_omap4_clkctrl_setup(struct device_node *node)
437 {
438 	struct omap_clkctrl_provider *provider;
439 	const struct omap_clkctrl_data *data = default_clkctrl_data;
440 	const struct omap_clkctrl_reg_data *reg_data;
441 	struct clk_init_data init = { NULL };
442 	struct clk_hw_omap *hw;
443 	struct clk *clk;
444 	struct omap_clkctrl_clk *clkctrl_clk;
445 	const __be32 *addrp;
446 	u32 addr;
447 	int ret;
448 	char *c;
449 	u16 soc_mask = 0;
450 
451 	if (!(ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT) &&
452 	    of_node_name_eq(node, "clk"))
453 		ti_clk_features.flags |= TI_CLK_CLKCTRL_COMPAT;
454 
455 	addrp = of_get_address(node, 0, NULL, NULL);
456 	addr = (u32)of_translate_address(node, addrp);
457 
458 #ifdef CONFIG_ARCH_OMAP4
459 	if (of_machine_is_compatible("ti,omap4"))
460 		data = omap4_clkctrl_data;
461 #endif
462 #ifdef CONFIG_SOC_OMAP5
463 	if (of_machine_is_compatible("ti,omap5"))
464 		data = omap5_clkctrl_data;
465 #endif
466 #ifdef CONFIG_SOC_DRA7XX
467 	if (of_machine_is_compatible("ti,dra7")) {
468 		if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
469 			data = dra7_clkctrl_compat_data;
470 		else
471 			data = dra7_clkctrl_data;
472 	}
473 
474 	if (of_machine_is_compatible("ti,dra72"))
475 		soc_mask = CLKF_SOC_DRA72;
476 	if (of_machine_is_compatible("ti,dra74"))
477 		soc_mask = CLKF_SOC_DRA74;
478 	if (of_machine_is_compatible("ti,dra76"))
479 		soc_mask = CLKF_SOC_DRA76;
480 #endif
481 #ifdef CONFIG_SOC_AM33XX
482 	if (of_machine_is_compatible("ti,am33xx")) {
483 		if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
484 			data = am3_clkctrl_compat_data;
485 		else
486 			data = am3_clkctrl_data;
487 	}
488 #endif
489 #ifdef CONFIG_SOC_AM43XX
490 	if (of_machine_is_compatible("ti,am4372")) {
491 		if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
492 			data = am4_clkctrl_compat_data;
493 		else
494 			data = am4_clkctrl_data;
495 	}
496 
497 	if (of_machine_is_compatible("ti,am438x")) {
498 		if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
499 			data = am438x_clkctrl_compat_data;
500 		else
501 			data = am438x_clkctrl_data;
502 	}
503 #endif
504 #ifdef CONFIG_SOC_TI81XX
505 	if (of_machine_is_compatible("ti,dm814"))
506 		data = dm814_clkctrl_data;
507 
508 	if (of_machine_is_compatible("ti,dm816"))
509 		data = dm816_clkctrl_data;
510 #endif
511 
512 	if (ti_clk_get_features()->flags & TI_CLK_DEVICE_TYPE_GP)
513 		soc_mask |= CLKF_SOC_NONSEC;
514 
515 	while (data->addr) {
516 		if (addr == data->addr)
517 			break;
518 
519 		data++;
520 	}
521 
522 	if (!data->addr) {
523 		pr_err("%pOF not found from clkctrl data.\n", node);
524 		return;
525 	}
526 
527 	provider = kzalloc(sizeof(*provider), GFP_KERNEL);
528 	if (!provider)
529 		return;
530 
531 	provider->base = of_iomap(node, 0);
532 
533 	if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT) {
534 		provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFnxxx", node->parent);
535 		if (!provider->clkdm_name) {
536 			kfree(provider);
537 			return;
538 		}
539 
540 		/*
541 		 * Create default clkdm name, replace _cm from end of parent
542 		 * node name with _clkdm
543 		 */
544 		provider->clkdm_name[strlen(provider->clkdm_name) - 2] = 0;
545 	} else {
546 		provider->clkdm_name = kasprintf(GFP_KERNEL, "%pOFn", node);
547 		if (!provider->clkdm_name) {
548 			kfree(provider);
549 			return;
550 		}
551 
552 		/*
553 		 * Create default clkdm name, replace _clkctrl from end of
554 		 * node name with _clkdm
555 		 */
556 		provider->clkdm_name[strlen(provider->clkdm_name) - 7] = 0;
557 	}
558 
559 	strcat(provider->clkdm_name, "clkdm");
560 
561 	/* Replace any dash from the clkdm name with underscore */
562 	c = provider->clkdm_name;
563 
564 	while (*c) {
565 		if (*c == '-')
566 			*c = '_';
567 		c++;
568 	}
569 
570 	INIT_LIST_HEAD(&provider->clocks);
571 
572 	/* Generate clocks */
573 	reg_data = data->regs;
574 
575 	while (reg_data->parent) {
576 		if ((reg_data->flags & CLKF_SOC_MASK) &&
577 		    (reg_data->flags & soc_mask) == 0) {
578 			reg_data++;
579 			continue;
580 		}
581 
582 		hw = kzalloc(sizeof(*hw), GFP_KERNEL);
583 		if (!hw)
584 			return;
585 
586 		hw->enable_reg.ptr = provider->base + reg_data->offset;
587 
588 		_ti_clkctrl_setup_subclks(provider, node, reg_data,
589 					  hw->enable_reg.ptr);
590 
591 		if (reg_data->flags & CLKF_SW_SUP)
592 			hw->enable_bit = MODULEMODE_SWCTRL;
593 		if (reg_data->flags & CLKF_HW_SUP)
594 			hw->enable_bit = MODULEMODE_HWCTRL;
595 		if (reg_data->flags & CLKF_NO_IDLEST)
596 			hw->flags |= NO_IDLEST;
597 
598 		if (reg_data->clkdm_name)
599 			hw->clkdm_name = reg_data->clkdm_name;
600 		else
601 			hw->clkdm_name = provider->clkdm_name;
602 
603 		init.parent_names = &reg_data->parent;
604 		init.num_parents = 1;
605 		init.flags = 0;
606 		if (reg_data->flags & CLKF_SET_RATE_PARENT)
607 			init.flags |= CLK_SET_RATE_PARENT;
608 		if (ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT)
609 			init.name = kasprintf(GFP_KERNEL, "%pOFn:%pOFn:%04x:%d",
610 					      node->parent, node,
611 					      reg_data->offset, 0);
612 		else
613 			init.name = kasprintf(GFP_KERNEL, "%pOFn:%04x:%d",
614 					      node, reg_data->offset, 0);
615 		clkctrl_clk = kzalloc(sizeof(*clkctrl_clk), GFP_KERNEL);
616 		if (!init.name || !clkctrl_clk)
617 			goto cleanup;
618 
619 		init.ops = &omap4_clkctrl_clk_ops;
620 		hw->hw.init = &init;
621 
622 		clk = ti_clk_register(NULL, &hw->hw, init.name);
623 		if (IS_ERR_OR_NULL(clk))
624 			goto cleanup;
625 
626 		clkctrl_clk->reg_offset = reg_data->offset;
627 		clkctrl_clk->clk = &hw->hw;
628 
629 		list_add(&clkctrl_clk->node, &provider->clocks);
630 
631 		reg_data++;
632 	}
633 
634 	ret = of_clk_add_hw_provider(node, _ti_omap4_clkctrl_xlate, provider);
635 	if (ret == -EPROBE_DEFER)
636 		ti_clk_retry_init(node, provider, _clkctrl_add_provider);
637 
638 	return;
639 
640 cleanup:
641 	kfree(hw);
642 	kfree(init.name);
643 	kfree(clkctrl_clk);
644 }
645 CLK_OF_DECLARE(ti_omap4_clkctrl_clock, "ti,clkctrl",
646 	       _ti_omap4_clkctrl_setup);
647