xref: /linux/drivers/clk/davinci/pll.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PLL clock driver for TI Davinci SoCs
4  *
5  * Copyright (C) 2018 David Lechner <david@lechnology.com>
6  *
7  * Based on arch/arm/mach-davinci/clock.c
8  * Copyright (C) 2006-2007 Texas Instruments.
9  * Copyright (C) 2008-2009 Deep Root Systems, LLC
10  */
11 
12 #include <linux/clk-provider.h>
13 #include <linux/clk.h>
14 #include <linux/clk/davinci.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/notifier.h>
21 #include <linux/of.h>
22 #include <linux/platform_data/clk-davinci-pll.h>
23 #include <linux/platform_device.h>
24 #include <linux/property.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 
29 #include "pll.h"
30 
31 #define MAX_NAME_SIZE	20
32 #define OSCIN_CLK_NAME	"oscin"
33 
34 #define REVID		0x000
35 #define PLLCTL		0x100
36 #define OCSEL		0x104
37 #define PLLSECCTL	0x108
38 #define PLLM		0x110
39 #define PREDIV		0x114
40 #define PLLDIV1		0x118
41 #define PLLDIV2		0x11c
42 #define PLLDIV3		0x120
43 #define OSCDIV		0x124
44 #define POSTDIV		0x128
45 #define BPDIV		0x12c
46 #define PLLCMD		0x138
47 #define PLLSTAT		0x13c
48 #define ALNCTL		0x140
49 #define DCHANGE		0x144
50 #define CKEN		0x148
51 #define CKSTAT		0x14c
52 #define SYSTAT		0x150
53 #define PLLDIV4		0x160
54 #define PLLDIV5		0x164
55 #define PLLDIV6		0x168
56 #define PLLDIV7		0x16c
57 #define PLLDIV8		0x170
58 #define PLLDIV9		0x174
59 
60 #define PLLCTL_PLLEN		BIT(0)
61 #define PLLCTL_PLLPWRDN		BIT(1)
62 #define PLLCTL_PLLRST		BIT(3)
63 #define PLLCTL_PLLDIS		BIT(4)
64 #define PLLCTL_PLLENSRC		BIT(5)
65 #define PLLCTL_CLKMODE		BIT(8)
66 
67 /* shared by most *DIV registers */
68 #define DIV_RATIO_SHIFT		0
69 #define DIV_RATIO_WIDTH		5
70 #define DIV_ENABLE_SHIFT	15
71 
72 #define PLLCMD_GOSET		BIT(0)
73 #define PLLSTAT_GOSTAT		BIT(0)
74 
75 #define CKEN_OBSCLK_SHIFT	1
76 #define CKEN_AUXEN_SHIFT	0
77 
78 /*
79  * OMAP-L138 system reference guide recommends a wait for 4 OSCIN/CLKIN
80  * cycles to ensure that the PLLC has switched to bypass mode. Delay of 1us
81  * ensures we are good for all > 4MHz OSCIN/CLKIN inputs. Typically the input
82  * is ~25MHz. Units are micro seconds.
83  */
84 #define PLL_BYPASS_TIME		1
85 
86 /* From OMAP-L138 datasheet table 6-4. Units are micro seconds */
87 #define PLL_RESET_TIME		1
88 
89 /*
90  * From OMAP-L138 datasheet table 6-4; assuming prediv = 1, sqrt(pllm) = 4
91  * Units are micro seconds.
92  */
93 #define PLL_LOCK_TIME		20
94 
95 /**
96  * struct davinci_pll_clk - Main PLL clock (aka PLLOUT)
97  * @hw: clk_hw for the pll
98  * @base: Base memory address
99  * @pllm_min: The minimum allowable PLLM[PLLM] value
100  * @pllm_max: The maximum allowable PLLM[PLLM] value
101  * @pllm_mask: Bitmask for PLLM[PLLM] value
102  */
103 struct davinci_pll_clk {
104 	struct clk_hw hw;
105 	void __iomem *base;
106 	u32 pllm_min;
107 	u32 pllm_max;
108 	u32 pllm_mask;
109 };
110 
111 #define to_davinci_pll_clk(_hw) \
112 	container_of((_hw), struct davinci_pll_clk, hw)
113 
114 static unsigned long davinci_pll_recalc_rate(struct clk_hw *hw,
115 					     unsigned long parent_rate)
116 {
117 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
118 	unsigned long rate = parent_rate;
119 	u32 mult;
120 
121 	mult = readl(pll->base + PLLM) & pll->pllm_mask;
122 	rate *= mult + 1;
123 
124 	return rate;
125 }
126 
127 static int davinci_pll_determine_rate(struct clk_hw *hw,
128 				      struct clk_rate_request *req)
129 {
130 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
131 	struct clk_hw *parent = req->best_parent_hw;
132 	unsigned long parent_rate = req->best_parent_rate;
133 	unsigned long rate = req->rate;
134 	unsigned long best_rate, r;
135 	u32 mult;
136 
137 	/* there is a limited range of valid outputs (see datasheet) */
138 	if (rate < req->min_rate)
139 		return -EINVAL;
140 
141 	rate = min(rate, req->max_rate);
142 	mult = rate / parent_rate;
143 	best_rate = parent_rate * mult;
144 
145 	/* easy case when there is no PREDIV */
146 	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
147 		if (best_rate < req->min_rate)
148 			return -EINVAL;
149 
150 		if (mult < pll->pllm_min || mult > pll->pllm_max)
151 			return -EINVAL;
152 
153 		req->rate = best_rate;
154 
155 		return 0;
156 	}
157 
158 	/* see if the PREDIV clock can help us */
159 	best_rate = 0;
160 
161 	for (mult = pll->pllm_min; mult <= pll->pllm_max; mult++) {
162 		parent_rate = clk_hw_round_rate(parent, rate / mult);
163 		r = parent_rate * mult;
164 		if (r < req->min_rate)
165 			continue;
166 		if (r > rate || r > req->max_rate)
167 			break;
168 		if (r > best_rate) {
169 			best_rate = r;
170 			req->rate = best_rate;
171 			req->best_parent_rate = parent_rate;
172 			if (best_rate == rate)
173 				break;
174 		}
175 	}
176 
177 	return 0;
178 }
179 
180 static int davinci_pll_set_rate(struct clk_hw *hw, unsigned long rate,
181 				unsigned long parent_rate)
182 {
183 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
184 	u32 mult;
185 
186 	mult = rate / parent_rate;
187 	writel(mult - 1, pll->base + PLLM);
188 
189 	return 0;
190 }
191 
192 #ifdef CONFIG_DEBUG_FS
193 static void davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry);
194 #else
195 #define davinci_pll_debug_init NULL
196 #endif
197 
198 static const struct clk_ops davinci_pll_ops = {
199 	.recalc_rate	= davinci_pll_recalc_rate,
200 	.determine_rate	= davinci_pll_determine_rate,
201 	.set_rate	= davinci_pll_set_rate,
202 	.debug_init	= davinci_pll_debug_init,
203 };
204 
205 /* PLLM works differently on DM365 */
206 static unsigned long dm365_pll_recalc_rate(struct clk_hw *hw,
207 					   unsigned long parent_rate)
208 {
209 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
210 	unsigned long rate = parent_rate;
211 	u32 mult;
212 
213 	mult = readl(pll->base + PLLM) & pll->pllm_mask;
214 	rate *= mult * 2;
215 
216 	return rate;
217 }
218 
219 static const struct clk_ops dm365_pll_ops = {
220 	.recalc_rate	= dm365_pll_recalc_rate,
221 	.debug_init	= davinci_pll_debug_init,
222 };
223 
224 /**
225  * davinci_pll_div_register - common *DIV clock implementation
226  * @dev: The PLL platform device or NULL
227  * @name: the clock name
228  * @parent_name: the parent clock name
229  * @reg: the *DIV register
230  * @fixed: if true, the divider is a fixed value
231  * @flags: bitmap of CLK_* flags from clock-provider.h
232  */
233 static struct clk *davinci_pll_div_register(struct device *dev,
234 					    const char *name,
235 					    const char *parent_name,
236 					    void __iomem *reg,
237 					    bool fixed, u32 flags)
238 {
239 	const char * const *parent_names = parent_name ? &parent_name : NULL;
240 	int num_parents = parent_name ? 1 : 0;
241 	const struct clk_ops *divider_ops = &clk_divider_ops;
242 	struct clk_gate *gate;
243 	struct clk_divider *divider;
244 	struct clk *clk;
245 	int ret;
246 
247 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
248 	if (!gate)
249 		return ERR_PTR(-ENOMEM);
250 
251 	gate->reg = reg;
252 	gate->bit_idx = DIV_ENABLE_SHIFT;
253 
254 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
255 	if (!divider) {
256 		ret = -ENOMEM;
257 		goto err_free_gate;
258 	}
259 
260 	divider->reg = reg;
261 	divider->shift = DIV_RATIO_SHIFT;
262 	divider->width = DIV_RATIO_WIDTH;
263 
264 	if (fixed) {
265 		divider->flags |= CLK_DIVIDER_READ_ONLY;
266 		divider_ops = &clk_divider_ro_ops;
267 	}
268 
269 	clk = clk_register_composite(dev, name, parent_names, num_parents,
270 				     NULL, NULL, &divider->hw, divider_ops,
271 				     &gate->hw, &clk_gate_ops, flags);
272 	if (IS_ERR(clk)) {
273 		ret = PTR_ERR(clk);
274 		goto err_free_divider;
275 	}
276 
277 	return clk;
278 
279 err_free_divider:
280 	kfree(divider);
281 err_free_gate:
282 	kfree(gate);
283 
284 	return ERR_PTR(ret);
285 }
286 
287 struct davinci_pllen_clk {
288 	struct clk_hw hw;
289 	void __iomem *base;
290 };
291 
292 #define to_davinci_pllen_clk(_hw) \
293 	container_of((_hw), struct davinci_pllen_clk, hw)
294 
295 static const struct clk_ops davinci_pllen_ops = {
296 	/* this clocks just uses the clock notification feature */
297 };
298 
299 /*
300  * The PLL has to be switched into bypass mode while we are chaning the rate,
301  * so we do that on the PLLEN clock since it is the end of the line. This will
302  * switch to bypass before any of the parent clocks (PREDIV, PLL, POSTDIV) are
303  * changed and will switch back to the PLL after the changes have been made.
304  */
305 static int davinci_pllen_rate_change(struct notifier_block *nb,
306 				     unsigned long flags, void *data)
307 {
308 	struct clk_notifier_data *cnd = data;
309 	struct clk_hw *hw = __clk_get_hw(cnd->clk);
310 	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
311 	u32 ctrl;
312 
313 	ctrl = readl(pll->base + PLLCTL);
314 
315 	if (flags == PRE_RATE_CHANGE) {
316 		/* Switch the PLL to bypass mode */
317 		ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
318 		writel(ctrl, pll->base + PLLCTL);
319 
320 		udelay(PLL_BYPASS_TIME);
321 
322 		/* Reset and enable PLL */
323 		ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS);
324 		writel(ctrl, pll->base + PLLCTL);
325 	} else {
326 		udelay(PLL_RESET_TIME);
327 
328 		/* Bring PLL out of reset */
329 		ctrl |= PLLCTL_PLLRST;
330 		writel(ctrl, pll->base + PLLCTL);
331 
332 		udelay(PLL_LOCK_TIME);
333 
334 		/* Remove PLL from bypass mode */
335 		ctrl |= PLLCTL_PLLEN;
336 		writel(ctrl, pll->base + PLLCTL);
337 	}
338 
339 	return NOTIFY_OK;
340 }
341 
342 static struct notifier_block davinci_pllen_notifier = {
343 	.notifier_call = davinci_pllen_rate_change,
344 };
345 
346 /**
347  * davinci_pll_clk_register - Register a PLL clock
348  * @dev: The PLL platform device or NULL
349  * @info: The device-specific clock info
350  * @parent_name: The parent clock name
351  * @base: The PLL's memory region
352  * @cfgchip: CFGCHIP syscon regmap for info->unlock_reg or NULL
353  *
354  * This creates a series of clocks that represent the PLL.
355  *
356  *     OSCIN > [PREDIV >] PLL > [POSTDIV >] PLLEN
357  *
358  * - OSCIN is the parent clock (on secondary PLL, may come from primary PLL)
359  * - PREDIV and POSTDIV are optional (depends on the PLL controller)
360  * - PLL is the PLL output (aka PLLOUT)
361  * - PLLEN is the bypass multiplexer
362  *
363  * Returns: The PLLOUT clock or a negative error code.
364  */
365 struct clk *davinci_pll_clk_register(struct device *dev,
366 				     const struct davinci_pll_clk_info *info,
367 				     const char *parent_name,
368 				     void __iomem *base,
369 				     struct regmap *cfgchip)
370 {
371 	char prediv_name[MAX_NAME_SIZE];
372 	char pllout_name[MAX_NAME_SIZE];
373 	char postdiv_name[MAX_NAME_SIZE];
374 	char pllen_name[MAX_NAME_SIZE];
375 	struct clk_init_data init;
376 	struct davinci_pll_clk *pllout;
377 	struct davinci_pllen_clk *pllen;
378 	struct clk *oscin_clk = NULL;
379 	struct clk *prediv_clk = NULL;
380 	struct clk *pllout_clk;
381 	struct clk *postdiv_clk = NULL;
382 	struct clk *pllen_clk;
383 	int ret;
384 
385 	if (info->flags & PLL_HAS_CLKMODE) {
386 		/*
387 		 * If a PLL has PLLCTL[CLKMODE], then it is the primary PLL.
388 		 * We register a clock named "oscin" that serves as the internal
389 		 * "input clock" domain shared by both PLLs (if there are 2)
390 		 * and will be the parent clock to the AUXCLK, SYSCLKBP and
391 		 * OBSCLK domains. NB: The various TRMs use "OSCIN" to mean
392 		 * a number of different things. In this driver we use it to
393 		 * mean the signal after the PLLCTL[CLKMODE] switch.
394 		 */
395 		oscin_clk = clk_register_fixed_factor(dev, OSCIN_CLK_NAME,
396 						      parent_name, 0, 1, 1);
397 		if (IS_ERR(oscin_clk))
398 			return oscin_clk;
399 
400 		parent_name = OSCIN_CLK_NAME;
401 	}
402 
403 	if (info->flags & PLL_HAS_PREDIV) {
404 		bool fixed = info->flags & PLL_PREDIV_FIXED_DIV;
405 		u32 flags = 0;
406 
407 		snprintf(prediv_name, MAX_NAME_SIZE, "%s_prediv", info->name);
408 
409 		if (info->flags & PLL_PREDIV_ALWAYS_ENABLED)
410 			flags |= CLK_IS_CRITICAL;
411 
412 		/* Some? DM355 chips don't correctly report the PREDIV value */
413 		if (info->flags & PLL_PREDIV_FIXED8)
414 			prediv_clk = clk_register_fixed_factor(dev, prediv_name,
415 							parent_name, flags, 1, 8);
416 		else
417 			prediv_clk = davinci_pll_div_register(dev, prediv_name,
418 				parent_name, base + PREDIV, fixed, flags);
419 		if (IS_ERR(prediv_clk)) {
420 			ret = PTR_ERR(prediv_clk);
421 			goto err_unregister_oscin;
422 		}
423 
424 		parent_name = prediv_name;
425 	}
426 
427 	/* Unlock writing to PLL registers */
428 	if (info->unlock_reg) {
429 		if (IS_ERR_OR_NULL(cfgchip))
430 			dev_warn(dev, "Failed to get CFGCHIP (%ld)\n",
431 				 PTR_ERR(cfgchip));
432 		else
433 			regmap_write_bits(cfgchip, info->unlock_reg,
434 					  info->unlock_mask, 0);
435 	}
436 
437 	pllout = kzalloc(sizeof(*pllout), GFP_KERNEL);
438 	if (!pllout) {
439 		ret = -ENOMEM;
440 		goto err_unregister_prediv;
441 	}
442 
443 	snprintf(pllout_name, MAX_NAME_SIZE, "%s_pllout", info->name);
444 
445 	init.name = pllout_name;
446 	if (info->flags & PLL_PLLM_2X)
447 		init.ops = &dm365_pll_ops;
448 	else
449 		init.ops = &davinci_pll_ops;
450 	init.parent_names = &parent_name;
451 	init.num_parents = 1;
452 	init.flags = 0;
453 
454 	if (info->flags & PLL_HAS_PREDIV)
455 		init.flags |= CLK_SET_RATE_PARENT;
456 
457 	pllout->hw.init = &init;
458 	pllout->base = base;
459 	pllout->pllm_mask = info->pllm_mask;
460 	pllout->pllm_min = info->pllm_min;
461 	pllout->pllm_max = info->pllm_max;
462 
463 	pllout_clk = clk_register(dev, &pllout->hw);
464 	if (IS_ERR(pllout_clk)) {
465 		ret = PTR_ERR(pllout_clk);
466 		goto err_free_pllout;
467 	}
468 
469 	clk_hw_set_rate_range(&pllout->hw, info->pllout_min_rate,
470 			      info->pllout_max_rate);
471 
472 	parent_name = pllout_name;
473 
474 	if (info->flags & PLL_HAS_POSTDIV) {
475 		bool fixed = info->flags & PLL_POSTDIV_FIXED_DIV;
476 		u32 flags = CLK_SET_RATE_PARENT;
477 
478 		snprintf(postdiv_name, MAX_NAME_SIZE, "%s_postdiv", info->name);
479 
480 		if (info->flags & PLL_POSTDIV_ALWAYS_ENABLED)
481 			flags |= CLK_IS_CRITICAL;
482 
483 		postdiv_clk = davinci_pll_div_register(dev, postdiv_name,
484 				parent_name, base + POSTDIV, fixed, flags);
485 		if (IS_ERR(postdiv_clk)) {
486 			ret = PTR_ERR(postdiv_clk);
487 			goto err_unregister_pllout;
488 		}
489 
490 		parent_name = postdiv_name;
491 	}
492 
493 	pllen = kzalloc(sizeof(*pllen), GFP_KERNEL);
494 	if (!pllen) {
495 		ret = -ENOMEM;
496 		goto err_unregister_postdiv;
497 	}
498 
499 	snprintf(pllen_name, MAX_NAME_SIZE, "%s_pllen", info->name);
500 
501 	init.name = pllen_name;
502 	init.ops = &davinci_pllen_ops;
503 	init.parent_names = &parent_name;
504 	init.num_parents = 1;
505 	init.flags = CLK_SET_RATE_PARENT;
506 
507 	pllen->hw.init = &init;
508 	pllen->base = base;
509 
510 	pllen_clk = clk_register(dev, &pllen->hw);
511 	if (IS_ERR(pllen_clk)) {
512 		ret = PTR_ERR(pllen_clk);
513 		goto err_free_pllen;
514 	}
515 
516 	clk_notifier_register(pllen_clk, &davinci_pllen_notifier);
517 
518 	return pllout_clk;
519 
520 err_free_pllen:
521 	kfree(pllen);
522 err_unregister_postdiv:
523 	clk_unregister(postdiv_clk);
524 err_unregister_pllout:
525 	clk_unregister(pllout_clk);
526 err_free_pllout:
527 	kfree(pllout);
528 err_unregister_prediv:
529 	clk_unregister(prediv_clk);
530 err_unregister_oscin:
531 	clk_unregister(oscin_clk);
532 
533 	return ERR_PTR(ret);
534 }
535 
536 /**
537  * davinci_pll_auxclk_register - Register bypass clock (AUXCLK)
538  * @dev: The PLL platform device or NULL
539  * @name: The clock name
540  * @base: The PLL memory region
541  */
542 struct clk *davinci_pll_auxclk_register(struct device *dev,
543 					const char *name,
544 					void __iomem *base)
545 {
546 	return clk_register_gate(dev, name, OSCIN_CLK_NAME, 0, base + CKEN,
547 				 CKEN_AUXEN_SHIFT, 0, NULL);
548 }
549 
550 /**
551  * davinci_pll_sysclkbp_clk_register - Register bypass divider clock (SYSCLKBP)
552  * @dev: The PLL platform device or NULL
553  * @name: The clock name
554  * @base: The PLL memory region
555  */
556 struct clk *davinci_pll_sysclkbp_clk_register(struct device *dev,
557 					      const char *name,
558 					      void __iomem *base)
559 {
560 	return clk_register_divider(dev, name, OSCIN_CLK_NAME, 0, base + BPDIV,
561 				    DIV_RATIO_SHIFT, DIV_RATIO_WIDTH,
562 				    CLK_DIVIDER_READ_ONLY, NULL);
563 }
564 
565 /**
566  * davinci_pll_obsclk_register - Register oscillator divider clock (OBSCLK)
567  * @dev: The PLL platform device or NULL
568  * @info: The clock info
569  * @base: The PLL memory region
570  */
571 struct clk *
572 davinci_pll_obsclk_register(struct device *dev,
573 			    const struct davinci_pll_obsclk_info *info,
574 			    void __iomem *base)
575 {
576 	struct clk_mux *mux;
577 	struct clk_gate *gate;
578 	struct clk_divider *divider;
579 	struct clk *clk;
580 	u32 oscdiv;
581 	int ret;
582 
583 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
584 	if (!mux)
585 		return ERR_PTR(-ENOMEM);
586 
587 	mux->reg = base + OCSEL;
588 	mux->table = info->table;
589 	mux->mask = info->ocsrc_mask;
590 
591 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
592 	if (!gate) {
593 		ret = -ENOMEM;
594 		goto err_free_mux;
595 	}
596 
597 	gate->reg = base + CKEN;
598 	gate->bit_idx = CKEN_OBSCLK_SHIFT;
599 
600 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
601 	if (!divider) {
602 		ret = -ENOMEM;
603 		goto err_free_gate;
604 	}
605 
606 	divider->reg = base + OSCDIV;
607 	divider->shift = DIV_RATIO_SHIFT;
608 	divider->width = DIV_RATIO_WIDTH;
609 
610 	/* make sure divider is enabled just in case bootloader disabled it */
611 	oscdiv = readl(base + OSCDIV);
612 	oscdiv |= BIT(DIV_ENABLE_SHIFT);
613 	writel(oscdiv, base + OSCDIV);
614 
615 	clk = clk_register_composite(dev, info->name, info->parent_names,
616 				     info->num_parents,
617 				     &mux->hw, &clk_mux_ops,
618 				     &divider->hw, &clk_divider_ops,
619 				     &gate->hw, &clk_gate_ops, 0);
620 
621 	if (IS_ERR(clk)) {
622 		ret = PTR_ERR(clk);
623 		goto err_free_divider;
624 	}
625 
626 	return clk;
627 
628 err_free_divider:
629 	kfree(divider);
630 err_free_gate:
631 	kfree(gate);
632 err_free_mux:
633 	kfree(mux);
634 
635 	return ERR_PTR(ret);
636 }
637 
638 /* The PLL SYSCLKn clocks have a mechanism for synchronizing rate changes. */
639 static int davinci_pll_sysclk_rate_change(struct notifier_block *nb,
640 					  unsigned long flags, void *data)
641 {
642 	struct clk_notifier_data *cnd = data;
643 	struct clk_hw *hw = __clk_get_hw(clk_get_parent(cnd->clk));
644 	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
645 	u32 pllcmd, pllstat;
646 
647 	switch (flags) {
648 	case POST_RATE_CHANGE:
649 		/* apply the changes */
650 		pllcmd = readl(pll->base + PLLCMD);
651 		pllcmd |= PLLCMD_GOSET;
652 		writel(pllcmd, pll->base + PLLCMD);
653 		fallthrough;
654 	case PRE_RATE_CHANGE:
655 		/* Wait until for outstanding changes to take effect */
656 		do {
657 			pllstat = readl(pll->base + PLLSTAT);
658 		} while (pllstat & PLLSTAT_GOSTAT);
659 		break;
660 	}
661 
662 	return NOTIFY_OK;
663 }
664 
665 static struct notifier_block davinci_pll_sysclk_notifier = {
666 	.notifier_call = davinci_pll_sysclk_rate_change,
667 };
668 
669 /**
670  * davinci_pll_sysclk_register - Register divider clocks (SYSCLKn)
671  * @dev: The PLL platform device or NULL
672  * @info: The clock info
673  * @base: The PLL memory region
674  */
675 struct clk *
676 davinci_pll_sysclk_register(struct device *dev,
677 			    const struct davinci_pll_sysclk_info *info,
678 			    void __iomem *base)
679 {
680 	const struct clk_ops *divider_ops = &clk_divider_ops;
681 	struct clk_gate *gate;
682 	struct clk_divider *divider;
683 	struct clk *clk;
684 	u32 reg;
685 	u32 flags = 0;
686 	int ret;
687 
688 	/* PLLDIVn registers are not entirely consecutive */
689 	if (info->id < 4)
690 		reg = PLLDIV1 + 4 * (info->id - 1);
691 	else
692 		reg = PLLDIV4 + 4 * (info->id - 4);
693 
694 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
695 	if (!gate)
696 		return ERR_PTR(-ENOMEM);
697 
698 	gate->reg = base + reg;
699 	gate->bit_idx = DIV_ENABLE_SHIFT;
700 
701 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
702 	if (!divider) {
703 		ret = -ENOMEM;
704 		goto err_free_gate;
705 	}
706 
707 	divider->reg = base + reg;
708 	divider->shift = DIV_RATIO_SHIFT;
709 	divider->width = info->ratio_width;
710 	divider->flags = 0;
711 
712 	if (info->flags & SYSCLK_FIXED_DIV) {
713 		divider->flags |= CLK_DIVIDER_READ_ONLY;
714 		divider_ops = &clk_divider_ro_ops;
715 	}
716 
717 	/* Only the ARM clock can change the parent PLL rate */
718 	if (info->flags & SYSCLK_ARM_RATE)
719 		flags |= CLK_SET_RATE_PARENT;
720 
721 	if (info->flags & SYSCLK_ALWAYS_ENABLED)
722 		flags |= CLK_IS_CRITICAL;
723 
724 	clk = clk_register_composite(dev, info->name, &info->parent_name, 1,
725 				     NULL, NULL, &divider->hw, divider_ops,
726 				     &gate->hw, &clk_gate_ops, flags);
727 	if (IS_ERR(clk)) {
728 		ret = PTR_ERR(clk);
729 		goto err_free_divider;
730 	}
731 
732 	clk_notifier_register(clk, &davinci_pll_sysclk_notifier);
733 
734 	return clk;
735 
736 err_free_divider:
737 	kfree(divider);
738 err_free_gate:
739 	kfree(gate);
740 
741 	return ERR_PTR(ret);
742 }
743 
744 int of_davinci_pll_init(struct device *dev, struct device_node *node,
745 			const struct davinci_pll_clk_info *info,
746 			const struct davinci_pll_obsclk_info *obsclk_info,
747 			const struct davinci_pll_sysclk_info **div_info,
748 			u8 max_sysclk_id,
749 			void __iomem *base,
750 			struct regmap *cfgchip)
751 {
752 	struct device_node *child;
753 	const char *parent_name;
754 	struct clk *clk;
755 
756 	if (info->flags & PLL_HAS_CLKMODE)
757 		parent_name = of_clk_get_parent_name(node, 0);
758 	else
759 		parent_name = OSCIN_CLK_NAME;
760 
761 	clk = davinci_pll_clk_register(dev, info, parent_name, base, cfgchip);
762 	if (IS_ERR(clk)) {
763 		dev_err(dev, "failed to register %s\n", info->name);
764 		return PTR_ERR(clk);
765 	}
766 
767 	child = of_get_child_by_name(node, "pllout");
768 	if (of_device_is_available(child))
769 		of_clk_add_provider(child, of_clk_src_simple_get, clk);
770 	of_node_put(child);
771 
772 	child = of_get_child_by_name(node, "sysclk");
773 	if (of_device_is_available(child)) {
774 		struct clk_onecell_data *clk_data;
775 		struct clk **clks;
776 		int n_clks =  max_sysclk_id + 1;
777 		int i;
778 
779 		clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
780 		if (!clk_data) {
781 			of_node_put(child);
782 			return -ENOMEM;
783 		}
784 
785 		clks = kmalloc_array(n_clks, sizeof(*clks), GFP_KERNEL);
786 		if (!clks) {
787 			kfree(clk_data);
788 			of_node_put(child);
789 			return -ENOMEM;
790 		}
791 
792 		clk_data->clks = clks;
793 		clk_data->clk_num = n_clks;
794 
795 		for (i = 0; i < n_clks; i++)
796 			clks[i] = ERR_PTR(-ENOENT);
797 
798 		for (; *div_info; div_info++) {
799 			clk = davinci_pll_sysclk_register(dev, *div_info, base);
800 			if (IS_ERR(clk))
801 				dev_warn(dev, "failed to register %s (%ld)\n",
802 					 (*div_info)->name, PTR_ERR(clk));
803 			else
804 				clks[(*div_info)->id] = clk;
805 		}
806 		of_clk_add_provider(child, of_clk_src_onecell_get, clk_data);
807 	}
808 	of_node_put(child);
809 
810 	child = of_get_child_by_name(node, "auxclk");
811 	if (of_device_is_available(child)) {
812 		char child_name[MAX_NAME_SIZE];
813 
814 		snprintf(child_name, MAX_NAME_SIZE, "%s_auxclk", info->name);
815 
816 		clk = davinci_pll_auxclk_register(dev, child_name, base);
817 		if (IS_ERR(clk))
818 			dev_warn(dev, "failed to register %s (%ld)\n",
819 				 child_name, PTR_ERR(clk));
820 		else
821 			of_clk_add_provider(child, of_clk_src_simple_get, clk);
822 	}
823 	of_node_put(child);
824 
825 	child = of_get_child_by_name(node, "obsclk");
826 	if (of_device_is_available(child)) {
827 		if (obsclk_info)
828 			clk = davinci_pll_obsclk_register(dev, obsclk_info, base);
829 		else
830 			clk = ERR_PTR(-EINVAL);
831 
832 		if (IS_ERR(clk))
833 			dev_warn(dev, "failed to register obsclk (%ld)\n",
834 				 PTR_ERR(clk));
835 		else
836 			of_clk_add_provider(child, of_clk_src_simple_get, clk);
837 	}
838 	of_node_put(child);
839 
840 	return 0;
841 }
842 
843 static struct davinci_pll_platform_data *davinci_pll_get_pdata(struct device *dev)
844 {
845 	struct davinci_pll_platform_data *pdata = dev_get_platdata(dev);
846 
847 	/*
848 	 * Platform data is optional, so allocate a new struct if one was not
849 	 * provided. For device tree, this will always be the case.
850 	 */
851 	if (!pdata)
852 		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
853 	if (!pdata)
854 		return NULL;
855 
856 	/* for device tree, we need to fill in the struct */
857 	if (dev->of_node)
858 		pdata->cfgchip =
859 			syscon_regmap_lookup_by_compatible("ti,da830-cfgchip");
860 
861 	return pdata;
862 }
863 
864 /* needed in early boot for clocksource/clockevent */
865 #ifdef CONFIG_ARCH_DAVINCI_DA850
866 CLK_OF_DECLARE(da850_pll0, "ti,da850-pll0", of_da850_pll0_init);
867 #endif
868 
869 static const struct of_device_id davinci_pll_of_match[] = {
870 #ifdef CONFIG_ARCH_DAVINCI_DA850
871 	{ .compatible = "ti,da850-pll1", .data = of_da850_pll1_init },
872 #endif
873 	{ }
874 };
875 
876 static const struct platform_device_id davinci_pll_id_table[] = {
877 #ifdef CONFIG_ARCH_DAVINCI_DA830
878 	{ .name = "da830-pll",   .driver_data = (kernel_ulong_t)da830_pll_init   },
879 #endif
880 #ifdef CONFIG_ARCH_DAVINCI_DA850
881 	{ .name = "da850-pll0",  .driver_data = (kernel_ulong_t)da850_pll0_init  },
882 	{ .name = "da850-pll1",  .driver_data = (kernel_ulong_t)da850_pll1_init  },
883 #endif
884 	{ }
885 };
886 
887 typedef int (*davinci_pll_init)(struct device *dev, void __iomem *base,
888 				struct regmap *cfgchip);
889 
890 static int davinci_pll_probe(struct platform_device *pdev)
891 {
892 	struct device *dev = &pdev->dev;
893 	struct davinci_pll_platform_data *pdata;
894 	davinci_pll_init pll_init = NULL;
895 	void __iomem *base;
896 
897 	pll_init = device_get_match_data(dev);
898 	if (!pll_init && pdev->id_entry)
899 		pll_init = (void *)pdev->id_entry->driver_data;
900 
901 	if (!pll_init) {
902 		dev_err(dev, "unable to find driver data\n");
903 		return -EINVAL;
904 	}
905 
906 	pdata = davinci_pll_get_pdata(dev);
907 	if (!pdata) {
908 		dev_err(dev, "missing platform data\n");
909 		return -EINVAL;
910 	}
911 
912 	base = devm_platform_ioremap_resource(pdev, 0);
913 	if (IS_ERR(base))
914 		return PTR_ERR(base);
915 
916 	return pll_init(dev, base, pdata->cfgchip);
917 }
918 
919 static struct platform_driver davinci_pll_driver = {
920 	.probe		= davinci_pll_probe,
921 	.driver		= {
922 		.name		= "davinci-pll-clk",
923 		.of_match_table	= davinci_pll_of_match,
924 	},
925 	.id_table	= davinci_pll_id_table,
926 };
927 
928 static int __init davinci_pll_driver_init(void)
929 {
930 	return platform_driver_register(&davinci_pll_driver);
931 }
932 
933 /* has to be postcore_initcall because PSC devices depend on PLL parent clocks */
934 postcore_initcall(davinci_pll_driver_init);
935 
936 #ifdef CONFIG_DEBUG_FS
937 #include <linux/debugfs.h>
938 
939 #define DEBUG_REG(n)	\
940 {			\
941 	.name	= #n,	\
942 	.offset	= n,	\
943 }
944 
945 static const struct debugfs_reg32 davinci_pll_regs[] = {
946 	DEBUG_REG(REVID),
947 	DEBUG_REG(PLLCTL),
948 	DEBUG_REG(OCSEL),
949 	DEBUG_REG(PLLSECCTL),
950 	DEBUG_REG(PLLM),
951 	DEBUG_REG(PREDIV),
952 	DEBUG_REG(PLLDIV1),
953 	DEBUG_REG(PLLDIV2),
954 	DEBUG_REG(PLLDIV3),
955 	DEBUG_REG(OSCDIV),
956 	DEBUG_REG(POSTDIV),
957 	DEBUG_REG(BPDIV),
958 	DEBUG_REG(PLLCMD),
959 	DEBUG_REG(PLLSTAT),
960 	DEBUG_REG(ALNCTL),
961 	DEBUG_REG(DCHANGE),
962 	DEBUG_REG(CKEN),
963 	DEBUG_REG(CKSTAT),
964 	DEBUG_REG(SYSTAT),
965 	DEBUG_REG(PLLDIV4),
966 	DEBUG_REG(PLLDIV5),
967 	DEBUG_REG(PLLDIV6),
968 	DEBUG_REG(PLLDIV7),
969 	DEBUG_REG(PLLDIV8),
970 	DEBUG_REG(PLLDIV9),
971 };
972 
973 static void davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry)
974 {
975 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
976 	struct debugfs_regset32 *regset;
977 
978 	regset = kzalloc(sizeof(*regset), GFP_KERNEL);
979 	if (!regset)
980 		return;
981 
982 	regset->regs = davinci_pll_regs;
983 	regset->nregs = ARRAY_SIZE(davinci_pll_regs);
984 	regset->base = pll->base;
985 
986 	debugfs_create_regset32("registers", 0400, dentry, regset);
987 }
988 #endif
989