xref: /openbmc/linux/drivers/clk/davinci/pll.c (revision 9aa2cba7)
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_address.h>
22 #include <linux/of_device.h>
23 #include <linux/of.h>
24 #include <linux/platform_data/clk-davinci-pll.h>
25 #include <linux/platform_device.h>
26 #include <linux/regmap.h>
27 #include <linux/slab.h>
28 #include <linux/types.h>
29 
30 #include "pll.h"
31 
32 #define MAX_NAME_SIZE	20
33 #define OSCIN_CLK_NAME	"oscin"
34 
35 #define REVID		0x000
36 #define PLLCTL		0x100
37 #define OCSEL		0x104
38 #define PLLSECCTL	0x108
39 #define PLLM		0x110
40 #define PREDIV		0x114
41 #define PLLDIV1		0x118
42 #define PLLDIV2		0x11c
43 #define PLLDIV3		0x120
44 #define OSCDIV		0x124
45 #define POSTDIV		0x128
46 #define BPDIV		0x12c
47 #define PLLCMD		0x138
48 #define PLLSTAT		0x13c
49 #define ALNCTL		0x140
50 #define DCHANGE		0x144
51 #define CKEN		0x148
52 #define CKSTAT		0x14c
53 #define SYSTAT		0x150
54 #define PLLDIV4		0x160
55 #define PLLDIV5		0x164
56 #define PLLDIV6		0x168
57 #define PLLDIV7		0x16c
58 #define PLLDIV8		0x170
59 #define PLLDIV9		0x174
60 
61 #define PLLCTL_PLLEN		BIT(0)
62 #define PLLCTL_PLLPWRDN		BIT(1)
63 #define PLLCTL_PLLRST		BIT(3)
64 #define PLLCTL_PLLDIS		BIT(4)
65 #define PLLCTL_PLLENSRC		BIT(5)
66 #define PLLCTL_CLKMODE		BIT(8)
67 
68 /* shared by most *DIV registers */
69 #define DIV_RATIO_SHIFT		0
70 #define DIV_RATIO_WIDTH		5
71 #define DIV_ENABLE_SHIFT	15
72 
73 #define PLLCMD_GOSET		BIT(0)
74 #define PLLSTAT_GOSTAT		BIT(0)
75 
76 #define CKEN_OBSCLK_SHIFT	1
77 #define CKEN_AUXEN_SHIFT	0
78 
79 /*
80  * OMAP-L138 system reference guide recommends a wait for 4 OSCIN/CLKIN
81  * cycles to ensure that the PLLC has switched to bypass mode. Delay of 1us
82  * ensures we are good for all > 4MHz OSCIN/CLKIN inputs. Typically the input
83  * is ~25MHz. Units are micro seconds.
84  */
85 #define PLL_BYPASS_TIME		1
86 
87 /* From OMAP-L138 datasheet table 6-4. Units are micro seconds */
88 #define PLL_RESET_TIME		1
89 
90 /*
91  * From OMAP-L138 datasheet table 6-4; assuming prediv = 1, sqrt(pllm) = 4
92  * Units are micro seconds.
93  */
94 #define PLL_LOCK_TIME		20
95 
96 /**
97  * struct davinci_pll_clk - Main PLL clock (aka PLLOUT)
98  * @hw: clk_hw for the pll
99  * @base: Base memory address
100  * @pllm_min: The minimum allowable PLLM[PLLM] value
101  * @pllm_max: The maximum allowable PLLM[PLLM] value
102  * @pllm_mask: Bitmask for PLLM[PLLM] value
103  */
104 struct davinci_pll_clk {
105 	struct clk_hw hw;
106 	void __iomem *base;
107 	u32 pllm_min;
108 	u32 pllm_max;
109 	u32 pllm_mask;
110 };
111 
112 #define to_davinci_pll_clk(_hw) \
113 	container_of((_hw), struct davinci_pll_clk, hw)
114 
115 static unsigned long davinci_pll_recalc_rate(struct clk_hw *hw,
116 					     unsigned long parent_rate)
117 {
118 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
119 	unsigned long rate = parent_rate;
120 	u32 mult;
121 
122 	mult = readl(pll->base + PLLM) & pll->pllm_mask;
123 	rate *= mult + 1;
124 
125 	return rate;
126 }
127 
128 static int davinci_pll_determine_rate(struct clk_hw *hw,
129 				      struct clk_rate_request *req)
130 {
131 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
132 	struct clk_hw *parent = req->best_parent_hw;
133 	unsigned long parent_rate = req->best_parent_rate;
134 	unsigned long rate = req->rate;
135 	unsigned long best_rate, r;
136 	u32 mult;
137 
138 	/* there is a limited range of valid outputs (see datasheet) */
139 	if (rate < req->min_rate)
140 		return -EINVAL;
141 
142 	rate = min(rate, req->max_rate);
143 	mult = rate / parent_rate;
144 	best_rate = parent_rate * mult;
145 
146 	/* easy case when there is no PREDIV */
147 	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
148 		if (best_rate < req->min_rate)
149 			return -EINVAL;
150 
151 		if (mult < pll->pllm_min || mult > pll->pllm_max)
152 			return -EINVAL;
153 
154 		req->rate = best_rate;
155 
156 		return 0;
157 	}
158 
159 	/* see if the PREDIV clock can help us */
160 	best_rate = 0;
161 
162 	for (mult = pll->pllm_min; mult <= pll->pllm_max; mult++) {
163 		parent_rate = clk_hw_round_rate(parent, rate / mult);
164 		r = parent_rate * mult;
165 		if (r < req->min_rate)
166 			continue;
167 		if (r > rate || r > req->max_rate)
168 			break;
169 		if (r > best_rate) {
170 			best_rate = r;
171 			req->rate = best_rate;
172 			req->best_parent_rate = parent_rate;
173 			if (best_rate == rate)
174 				break;
175 		}
176 	}
177 
178 	return 0;
179 }
180 
181 static int davinci_pll_set_rate(struct clk_hw *hw, unsigned long rate,
182 				unsigned long parent_rate)
183 {
184 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
185 	u32 mult;
186 
187 	mult = rate / parent_rate;
188 	writel(mult - 1, pll->base + PLLM);
189 
190 	return 0;
191 }
192 
193 #ifdef CONFIG_DEBUG_FS
194 static void davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry);
195 #else
196 #define davinci_pll_debug_init NULL
197 #endif
198 
199 static const struct clk_ops davinci_pll_ops = {
200 	.recalc_rate	= davinci_pll_recalc_rate,
201 	.determine_rate	= davinci_pll_determine_rate,
202 	.set_rate	= davinci_pll_set_rate,
203 	.debug_init	= davinci_pll_debug_init,
204 };
205 
206 /* PLLM works differently on DM365 */
207 static unsigned long dm365_pll_recalc_rate(struct clk_hw *hw,
208 					   unsigned long parent_rate)
209 {
210 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
211 	unsigned long rate = parent_rate;
212 	u32 mult;
213 
214 	mult = readl(pll->base + PLLM) & pll->pllm_mask;
215 	rate *= mult * 2;
216 
217 	return rate;
218 }
219 
220 static const struct clk_ops dm365_pll_ops = {
221 	.recalc_rate	= dm365_pll_recalc_rate,
222 	.debug_init	= davinci_pll_debug_init,
223 };
224 
225 /**
226  * davinci_pll_div_register - common *DIV clock implementation
227  * @dev: The PLL platform device or NULL
228  * @name: the clock name
229  * @parent_name: the parent clock name
230  * @reg: the *DIV register
231  * @fixed: if true, the divider is a fixed value
232  * @flags: bitmap of CLK_* flags from clock-provider.h
233  */
234 static struct clk *davinci_pll_div_register(struct device *dev,
235 					    const char *name,
236 					    const char *parent_name,
237 					    void __iomem *reg,
238 					    bool fixed, u32 flags)
239 {
240 	const char * const *parent_names = parent_name ? &parent_name : NULL;
241 	int num_parents = parent_name ? 1 : 0;
242 	const struct clk_ops *divider_ops = &clk_divider_ops;
243 	struct clk_gate *gate;
244 	struct clk_divider *divider;
245 	struct clk *clk;
246 	int ret;
247 
248 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
249 	if (!gate)
250 		return ERR_PTR(-ENOMEM);
251 
252 	gate->reg = reg;
253 	gate->bit_idx = DIV_ENABLE_SHIFT;
254 
255 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
256 	if (!divider) {
257 		ret = -ENOMEM;
258 		goto err_free_gate;
259 	}
260 
261 	divider->reg = reg;
262 	divider->shift = DIV_RATIO_SHIFT;
263 	divider->width = DIV_RATIO_WIDTH;
264 
265 	if (fixed) {
266 		divider->flags |= CLK_DIVIDER_READ_ONLY;
267 		divider_ops = &clk_divider_ro_ops;
268 	}
269 
270 	clk = clk_register_composite(dev, name, parent_names, num_parents,
271 				     NULL, NULL, &divider->hw, divider_ops,
272 				     &gate->hw, &clk_gate_ops, flags);
273 	if (IS_ERR(clk)) {
274 		ret = PTR_ERR(clk);
275 		goto err_free_divider;
276 	}
277 
278 	return clk;
279 
280 err_free_divider:
281 	kfree(divider);
282 err_free_gate:
283 	kfree(gate);
284 
285 	return ERR_PTR(ret);
286 }
287 
288 struct davinci_pllen_clk {
289 	struct clk_hw hw;
290 	void __iomem *base;
291 };
292 
293 #define to_davinci_pllen_clk(_hw) \
294 	container_of((_hw), struct davinci_pllen_clk, hw)
295 
296 static const struct clk_ops davinci_pllen_ops = {
297 	/* this clocks just uses the clock notification feature */
298 };
299 
300 /*
301  * The PLL has to be switched into bypass mode while we are chaning the rate,
302  * so we do that on the PLLEN clock since it is the end of the line. This will
303  * switch to bypass before any of the parent clocks (PREDIV, PLL, POSTDIV) are
304  * changed and will switch back to the PLL after the changes have been made.
305  */
306 static int davinci_pllen_rate_change(struct notifier_block *nb,
307 				     unsigned long flags, void *data)
308 {
309 	struct clk_notifier_data *cnd = data;
310 	struct clk_hw *hw = __clk_get_hw(cnd->clk);
311 	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
312 	u32 ctrl;
313 
314 	ctrl = readl(pll->base + PLLCTL);
315 
316 	if (flags == PRE_RATE_CHANGE) {
317 		/* Switch the PLL to bypass mode */
318 		ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
319 		writel(ctrl, pll->base + PLLCTL);
320 
321 		udelay(PLL_BYPASS_TIME);
322 
323 		/* Reset and enable PLL */
324 		ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS);
325 		writel(ctrl, pll->base + PLLCTL);
326 	} else {
327 		udelay(PLL_RESET_TIME);
328 
329 		/* Bring PLL out of reset */
330 		ctrl |= PLLCTL_PLLRST;
331 		writel(ctrl, pll->base + PLLCTL);
332 
333 		udelay(PLL_LOCK_TIME);
334 
335 		/* Remove PLL from bypass mode */
336 		ctrl |= PLLCTL_PLLEN;
337 		writel(ctrl, pll->base + PLLCTL);
338 	}
339 
340 	return NOTIFY_OK;
341 }
342 
343 static struct notifier_block davinci_pllen_notifier = {
344 	.notifier_call = davinci_pllen_rate_change,
345 };
346 
347 /**
348  * davinci_pll_clk_register - Register a PLL clock
349  * @dev: The PLL platform device or NULL
350  * @info: The device-specific clock info
351  * @parent_name: The parent clock name
352  * @base: The PLL's memory region
353  * @cfgchip: CFGCHIP syscon regmap for info->unlock_reg or NULL
354  *
355  * This creates a series of clocks that represent the PLL.
356  *
357  *     OSCIN > [PREDIV >] PLL > [POSTDIV >] PLLEN
358  *
359  * - OSCIN is the parent clock (on secondary PLL, may come from primary PLL)
360  * - PREDIV and POSTDIV are optional (depends on the PLL controller)
361  * - PLL is the PLL output (aka PLLOUT)
362  * - PLLEN is the bypass multiplexer
363  *
364  * Returns: The PLLOUT clock or a negative error code.
365  */
366 struct clk *davinci_pll_clk_register(struct device *dev,
367 				     const struct davinci_pll_clk_info *info,
368 				     const char *parent_name,
369 				     void __iomem *base,
370 				     struct regmap *cfgchip)
371 {
372 	char prediv_name[MAX_NAME_SIZE];
373 	char pllout_name[MAX_NAME_SIZE];
374 	char postdiv_name[MAX_NAME_SIZE];
375 	char pllen_name[MAX_NAME_SIZE];
376 	struct clk_init_data init;
377 	struct davinci_pll_clk *pllout;
378 	struct davinci_pllen_clk *pllen;
379 	struct clk *oscin_clk = NULL;
380 	struct clk *prediv_clk = NULL;
381 	struct clk *pllout_clk;
382 	struct clk *postdiv_clk = NULL;
383 	struct clk *pllen_clk;
384 	int ret;
385 
386 	if (info->flags & PLL_HAS_CLKMODE) {
387 		/*
388 		 * If a PLL has PLLCTL[CLKMODE], then it is the primary PLL.
389 		 * We register a clock named "oscin" that serves as the internal
390 		 * "input clock" domain shared by both PLLs (if there are 2)
391 		 * and will be the parent clock to the AUXCLK, SYSCLKBP and
392 		 * OBSCLK domains. NB: The various TRMs use "OSCIN" to mean
393 		 * a number of different things. In this driver we use it to
394 		 * mean the signal after the PLLCTL[CLKMODE] switch.
395 		 */
396 		oscin_clk = clk_register_fixed_factor(dev, OSCIN_CLK_NAME,
397 						      parent_name, 0, 1, 1);
398 		if (IS_ERR(oscin_clk))
399 			return oscin_clk;
400 
401 		parent_name = OSCIN_CLK_NAME;
402 	}
403 
404 	if (info->flags & PLL_HAS_PREDIV) {
405 		bool fixed = info->flags & PLL_PREDIV_FIXED_DIV;
406 		u32 flags = 0;
407 
408 		snprintf(prediv_name, MAX_NAME_SIZE, "%s_prediv", info->name);
409 
410 		if (info->flags & PLL_PREDIV_ALWAYS_ENABLED)
411 			flags |= CLK_IS_CRITICAL;
412 
413 		/* Some? DM355 chips don't correctly report the PREDIV value */
414 		if (info->flags & PLL_PREDIV_FIXED8)
415 			prediv_clk = clk_register_fixed_factor(dev, prediv_name,
416 							parent_name, flags, 1, 8);
417 		else
418 			prediv_clk = davinci_pll_div_register(dev, prediv_name,
419 				parent_name, base + PREDIV, fixed, flags);
420 		if (IS_ERR(prediv_clk)) {
421 			ret = PTR_ERR(prediv_clk);
422 			goto err_unregister_oscin;
423 		}
424 
425 		parent_name = prediv_name;
426 	}
427 
428 	/* Unlock writing to PLL registers */
429 	if (info->unlock_reg) {
430 		if (IS_ERR_OR_NULL(cfgchip))
431 			dev_warn(dev, "Failed to get CFGCHIP (%ld)\n",
432 				 PTR_ERR(cfgchip));
433 		else
434 			regmap_write_bits(cfgchip, info->unlock_reg,
435 					  info->unlock_mask, 0);
436 	}
437 
438 	pllout = kzalloc(sizeof(*pllout), GFP_KERNEL);
439 	if (!pllout) {
440 		ret = -ENOMEM;
441 		goto err_unregister_prediv;
442 	}
443 
444 	snprintf(pllout_name, MAX_NAME_SIZE, "%s_pllout", info->name);
445 
446 	init.name = pllout_name;
447 	if (info->flags & PLL_PLLM_2X)
448 		init.ops = &dm365_pll_ops;
449 	else
450 		init.ops = &davinci_pll_ops;
451 	init.parent_names = &parent_name;
452 	init.num_parents = 1;
453 	init.flags = 0;
454 
455 	if (info->flags & PLL_HAS_PREDIV)
456 		init.flags |= CLK_SET_RATE_PARENT;
457 
458 	pllout->hw.init = &init;
459 	pllout->base = base;
460 	pllout->pllm_mask = info->pllm_mask;
461 	pllout->pllm_min = info->pllm_min;
462 	pllout->pllm_max = info->pllm_max;
463 
464 	pllout_clk = clk_register(dev, &pllout->hw);
465 	if (IS_ERR(pllout_clk)) {
466 		ret = PTR_ERR(pllout_clk);
467 		goto err_free_pllout;
468 	}
469 
470 	clk_hw_set_rate_range(&pllout->hw, info->pllout_min_rate,
471 			      info->pllout_max_rate);
472 
473 	parent_name = pllout_name;
474 
475 	if (info->flags & PLL_HAS_POSTDIV) {
476 		bool fixed = info->flags & PLL_POSTDIV_FIXED_DIV;
477 		u32 flags = CLK_SET_RATE_PARENT;
478 
479 		snprintf(postdiv_name, MAX_NAME_SIZE, "%s_postdiv", info->name);
480 
481 		if (info->flags & PLL_POSTDIV_ALWAYS_ENABLED)
482 			flags |= CLK_IS_CRITICAL;
483 
484 		postdiv_clk = davinci_pll_div_register(dev, postdiv_name,
485 				parent_name, base + POSTDIV, fixed, flags);
486 		if (IS_ERR(postdiv_clk)) {
487 			ret = PTR_ERR(postdiv_clk);
488 			goto err_unregister_pllout;
489 		}
490 
491 		parent_name = postdiv_name;
492 	}
493 
494 	pllen = kzalloc(sizeof(*pllen), GFP_KERNEL);
495 	if (!pllen) {
496 		ret = -ENOMEM;
497 		goto err_unregister_postdiv;
498 	}
499 
500 	snprintf(pllen_name, MAX_NAME_SIZE, "%s_pllen", info->name);
501 
502 	init.name = pllen_name;
503 	init.ops = &davinci_pllen_ops;
504 	init.parent_names = &parent_name;
505 	init.num_parents = 1;
506 	init.flags = CLK_SET_RATE_PARENT;
507 
508 	pllen->hw.init = &init;
509 	pllen->base = base;
510 
511 	pllen_clk = clk_register(dev, &pllen->hw);
512 	if (IS_ERR(pllen_clk)) {
513 		ret = PTR_ERR(pllen_clk);
514 		goto err_free_pllen;
515 	}
516 
517 	clk_notifier_register(pllen_clk, &davinci_pllen_notifier);
518 
519 	return pllout_clk;
520 
521 err_free_pllen:
522 	kfree(pllen);
523 err_unregister_postdiv:
524 	clk_unregister(postdiv_clk);
525 err_unregister_pllout:
526 	clk_unregister(pllout_clk);
527 err_free_pllout:
528 	kfree(pllout);
529 err_unregister_prediv:
530 	clk_unregister(prediv_clk);
531 err_unregister_oscin:
532 	clk_unregister(oscin_clk);
533 
534 	return ERR_PTR(ret);
535 }
536 
537 /**
538  * davinci_pll_auxclk_register - Register bypass clock (AUXCLK)
539  * @dev: The PLL platform device or NULL
540  * @name: The clock name
541  * @base: The PLL memory region
542  */
543 struct clk *davinci_pll_auxclk_register(struct device *dev,
544 					const char *name,
545 					void __iomem *base)
546 {
547 	return clk_register_gate(dev, name, OSCIN_CLK_NAME, 0, base + CKEN,
548 				 CKEN_AUXEN_SHIFT, 0, NULL);
549 }
550 
551 /**
552  * davinci_pll_sysclkbp_clk_register - Register bypass divider clock (SYSCLKBP)
553  * @dev: The PLL platform device or NULL
554  * @name: The clock name
555  * @base: The PLL memory region
556  */
557 struct clk *davinci_pll_sysclkbp_clk_register(struct device *dev,
558 					      const char *name,
559 					      void __iomem *base)
560 {
561 	return clk_register_divider(dev, name, OSCIN_CLK_NAME, 0, base + BPDIV,
562 				    DIV_RATIO_SHIFT, DIV_RATIO_WIDTH,
563 				    CLK_DIVIDER_READ_ONLY, NULL);
564 }
565 
566 /**
567  * davinci_pll_obsclk_register - Register oscillator divider clock (OBSCLK)
568  * @dev: The PLL platform device or NULL
569  * @info: The clock info
570  * @base: The PLL memory region
571  */
572 struct clk *
573 davinci_pll_obsclk_register(struct device *dev,
574 			    const struct davinci_pll_obsclk_info *info,
575 			    void __iomem *base)
576 {
577 	struct clk_mux *mux;
578 	struct clk_gate *gate;
579 	struct clk_divider *divider;
580 	struct clk *clk;
581 	u32 oscdiv;
582 	int ret;
583 
584 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
585 	if (!mux)
586 		return ERR_PTR(-ENOMEM);
587 
588 	mux->reg = base + OCSEL;
589 	mux->table = info->table;
590 	mux->mask = info->ocsrc_mask;
591 
592 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
593 	if (!gate) {
594 		ret = -ENOMEM;
595 		goto err_free_mux;
596 	}
597 
598 	gate->reg = base + CKEN;
599 	gate->bit_idx = CKEN_OBSCLK_SHIFT;
600 
601 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
602 	if (!divider) {
603 		ret = -ENOMEM;
604 		goto err_free_gate;
605 	}
606 
607 	divider->reg = base + OSCDIV;
608 	divider->shift = DIV_RATIO_SHIFT;
609 	divider->width = DIV_RATIO_WIDTH;
610 
611 	/* make sure divider is enabled just in case bootloader disabled it */
612 	oscdiv = readl(base + OSCDIV);
613 	oscdiv |= BIT(DIV_ENABLE_SHIFT);
614 	writel(oscdiv, base + OSCDIV);
615 
616 	clk = clk_register_composite(dev, info->name, info->parent_names,
617 				     info->num_parents,
618 				     &mux->hw, &clk_mux_ops,
619 				     &divider->hw, &clk_divider_ops,
620 				     &gate->hw, &clk_gate_ops, 0);
621 
622 	if (IS_ERR(clk)) {
623 		ret = PTR_ERR(clk);
624 		goto err_free_divider;
625 	}
626 
627 	return clk;
628 
629 err_free_divider:
630 	kfree(divider);
631 err_free_gate:
632 	kfree(gate);
633 err_free_mux:
634 	kfree(mux);
635 
636 	return ERR_PTR(ret);
637 }
638 
639 /* The PLL SYSCLKn clocks have a mechanism for synchronizing rate changes. */
640 static int davinci_pll_sysclk_rate_change(struct notifier_block *nb,
641 					  unsigned long flags, void *data)
642 {
643 	struct clk_notifier_data *cnd = data;
644 	struct clk_hw *hw = __clk_get_hw(clk_get_parent(cnd->clk));
645 	struct davinci_pllen_clk *pll = to_davinci_pllen_clk(hw);
646 	u32 pllcmd, pllstat;
647 
648 	switch (flags) {
649 	case POST_RATE_CHANGE:
650 		/* apply the changes */
651 		pllcmd = readl(pll->base + PLLCMD);
652 		pllcmd |= PLLCMD_GOSET;
653 		writel(pllcmd, pll->base + PLLCMD);
654 		fallthrough;
655 	case PRE_RATE_CHANGE:
656 		/* Wait until for outstanding changes to take effect */
657 		do {
658 			pllstat = readl(pll->base + PLLSTAT);
659 		} while (pllstat & PLLSTAT_GOSTAT);
660 		break;
661 	}
662 
663 	return NOTIFY_OK;
664 }
665 
666 static struct notifier_block davinci_pll_sysclk_notifier = {
667 	.notifier_call = davinci_pll_sysclk_rate_change,
668 };
669 
670 /**
671  * davinci_pll_sysclk_register - Register divider clocks (SYSCLKn)
672  * @dev: The PLL platform device or NULL
673  * @info: The clock info
674  * @base: The PLL memory region
675  */
676 struct clk *
677 davinci_pll_sysclk_register(struct device *dev,
678 			    const struct davinci_pll_sysclk_info *info,
679 			    void __iomem *base)
680 {
681 	const struct clk_ops *divider_ops = &clk_divider_ops;
682 	struct clk_gate *gate;
683 	struct clk_divider *divider;
684 	struct clk *clk;
685 	u32 reg;
686 	u32 flags = 0;
687 	int ret;
688 
689 	/* PLLDIVn registers are not entirely consecutive */
690 	if (info->id < 4)
691 		reg = PLLDIV1 + 4 * (info->id - 1);
692 	else
693 		reg = PLLDIV4 + 4 * (info->id - 4);
694 
695 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
696 	if (!gate)
697 		return ERR_PTR(-ENOMEM);
698 
699 	gate->reg = base + reg;
700 	gate->bit_idx = DIV_ENABLE_SHIFT;
701 
702 	divider = kzalloc(sizeof(*divider), GFP_KERNEL);
703 	if (!divider) {
704 		ret = -ENOMEM;
705 		goto err_free_gate;
706 	}
707 
708 	divider->reg = base + reg;
709 	divider->shift = DIV_RATIO_SHIFT;
710 	divider->width = info->ratio_width;
711 	divider->flags = 0;
712 
713 	if (info->flags & SYSCLK_FIXED_DIV) {
714 		divider->flags |= CLK_DIVIDER_READ_ONLY;
715 		divider_ops = &clk_divider_ro_ops;
716 	}
717 
718 	/* Only the ARM clock can change the parent PLL rate */
719 	if (info->flags & SYSCLK_ARM_RATE)
720 		flags |= CLK_SET_RATE_PARENT;
721 
722 	if (info->flags & SYSCLK_ALWAYS_ENABLED)
723 		flags |= CLK_IS_CRITICAL;
724 
725 	clk = clk_register_composite(dev, info->name, &info->parent_name, 1,
726 				     NULL, NULL, &divider->hw, divider_ops,
727 				     &gate->hw, &clk_gate_ops, flags);
728 	if (IS_ERR(clk)) {
729 		ret = PTR_ERR(clk);
730 		goto err_free_divider;
731 	}
732 
733 	clk_notifier_register(clk, &davinci_pll_sysclk_notifier);
734 
735 	return clk;
736 
737 err_free_divider:
738 	kfree(divider);
739 err_free_gate:
740 	kfree(gate);
741 
742 	return ERR_PTR(ret);
743 }
744 
745 int of_davinci_pll_init(struct device *dev, struct device_node *node,
746 			const struct davinci_pll_clk_info *info,
747 			const struct davinci_pll_obsclk_info *obsclk_info,
748 			const struct davinci_pll_sysclk_info **div_info,
749 			u8 max_sysclk_id,
750 			void __iomem *base,
751 			struct regmap *cfgchip)
752 {
753 	struct device_node *child;
754 	const char *parent_name;
755 	struct clk *clk;
756 
757 	if (info->flags & PLL_HAS_CLKMODE)
758 		parent_name = of_clk_get_parent_name(node, 0);
759 	else
760 		parent_name = OSCIN_CLK_NAME;
761 
762 	clk = davinci_pll_clk_register(dev, info, parent_name, base, cfgchip);
763 	if (IS_ERR(clk)) {
764 		dev_err(dev, "failed to register %s\n", info->name);
765 		return PTR_ERR(clk);
766 	}
767 
768 	child = of_get_child_by_name(node, "pllout");
769 	if (of_device_is_available(child))
770 		of_clk_add_provider(child, of_clk_src_simple_get, clk);
771 	of_node_put(child);
772 
773 	child = of_get_child_by_name(node, "sysclk");
774 	if (of_device_is_available(child)) {
775 		struct clk_onecell_data *clk_data;
776 		struct clk **clks;
777 		int n_clks =  max_sysclk_id + 1;
778 		int i;
779 
780 		clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
781 		if (!clk_data) {
782 			of_node_put(child);
783 			return -ENOMEM;
784 		}
785 
786 		clks = kmalloc_array(n_clks, sizeof(*clks), GFP_KERNEL);
787 		if (!clks) {
788 			kfree(clk_data);
789 			of_node_put(child);
790 			return -ENOMEM;
791 		}
792 
793 		clk_data->clks = clks;
794 		clk_data->clk_num = n_clks;
795 
796 		for (i = 0; i < n_clks; i++)
797 			clks[i] = ERR_PTR(-ENOENT);
798 
799 		for (; *div_info; div_info++) {
800 			clk = davinci_pll_sysclk_register(dev, *div_info, base);
801 			if (IS_ERR(clk))
802 				dev_warn(dev, "failed to register %s (%ld)\n",
803 					 (*div_info)->name, PTR_ERR(clk));
804 			else
805 				clks[(*div_info)->id] = clk;
806 		}
807 		of_clk_add_provider(child, of_clk_src_onecell_get, clk_data);
808 	}
809 	of_node_put(child);
810 
811 	child = of_get_child_by_name(node, "auxclk");
812 	if (of_device_is_available(child)) {
813 		char child_name[MAX_NAME_SIZE];
814 
815 		snprintf(child_name, MAX_NAME_SIZE, "%s_auxclk", info->name);
816 
817 		clk = davinci_pll_auxclk_register(dev, child_name, base);
818 		if (IS_ERR(clk))
819 			dev_warn(dev, "failed to register %s (%ld)\n",
820 				 child_name, PTR_ERR(clk));
821 		else
822 			of_clk_add_provider(child, of_clk_src_simple_get, clk);
823 	}
824 	of_node_put(child);
825 
826 	child = of_get_child_by_name(node, "obsclk");
827 	if (of_device_is_available(child)) {
828 		if (obsclk_info)
829 			clk = davinci_pll_obsclk_register(dev, obsclk_info, base);
830 		else
831 			clk = ERR_PTR(-EINVAL);
832 
833 		if (IS_ERR(clk))
834 			dev_warn(dev, "failed to register obsclk (%ld)\n",
835 				 PTR_ERR(clk));
836 		else
837 			of_clk_add_provider(child, of_clk_src_simple_get, clk);
838 	}
839 	of_node_put(child);
840 
841 	return 0;
842 }
843 
844 static struct davinci_pll_platform_data *davinci_pll_get_pdata(struct device *dev)
845 {
846 	struct davinci_pll_platform_data *pdata = dev_get_platdata(dev);
847 
848 	/*
849 	 * Platform data is optional, so allocate a new struct if one was not
850 	 * provided. For device tree, this will always be the case.
851 	 */
852 	if (!pdata)
853 		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
854 	if (!pdata)
855 		return NULL;
856 
857 	/* for device tree, we need to fill in the struct */
858 	if (dev->of_node)
859 		pdata->cfgchip =
860 			syscon_regmap_lookup_by_compatible("ti,da830-cfgchip");
861 
862 	return pdata;
863 }
864 
865 /* needed in early boot for clocksource/clockevent */
866 #ifdef CONFIG_ARCH_DAVINCI_DA850
867 CLK_OF_DECLARE(da850_pll0, "ti,da850-pll0", of_da850_pll0_init);
868 #endif
869 
870 static const struct of_device_id davinci_pll_of_match[] = {
871 #ifdef CONFIG_ARCH_DAVINCI_DA850
872 	{ .compatible = "ti,da850-pll1", .data = of_da850_pll1_init },
873 #endif
874 	{ }
875 };
876 
877 static const struct platform_device_id davinci_pll_id_table[] = {
878 #ifdef CONFIG_ARCH_DAVINCI_DA830
879 	{ .name = "da830-pll",   .driver_data = (kernel_ulong_t)da830_pll_init   },
880 #endif
881 #ifdef CONFIG_ARCH_DAVINCI_DA850
882 	{ .name = "da850-pll0",  .driver_data = (kernel_ulong_t)da850_pll0_init  },
883 	{ .name = "da850-pll1",  .driver_data = (kernel_ulong_t)da850_pll1_init  },
884 #endif
885 	{ }
886 };
887 
888 typedef int (*davinci_pll_init)(struct device *dev, void __iomem *base,
889 				struct regmap *cfgchip);
890 
891 static int davinci_pll_probe(struct platform_device *pdev)
892 {
893 	struct device *dev = &pdev->dev;
894 	struct davinci_pll_platform_data *pdata;
895 	const struct of_device_id *of_id;
896 	davinci_pll_init pll_init = NULL;
897 	void __iomem *base;
898 
899 	of_id = of_match_device(davinci_pll_of_match, dev);
900 	if (of_id)
901 		pll_init = of_id->data;
902 	else if (pdev->id_entry)
903 		pll_init = (void *)pdev->id_entry->driver_data;
904 
905 	if (!pll_init) {
906 		dev_err(dev, "unable to find driver data\n");
907 		return -EINVAL;
908 	}
909 
910 	pdata = davinci_pll_get_pdata(dev);
911 	if (!pdata) {
912 		dev_err(dev, "missing platform data\n");
913 		return -EINVAL;
914 	}
915 
916 	base = devm_platform_ioremap_resource(pdev, 0);
917 	if (IS_ERR(base))
918 		return PTR_ERR(base);
919 
920 	return pll_init(dev, base, pdata->cfgchip);
921 }
922 
923 static struct platform_driver davinci_pll_driver = {
924 	.probe		= davinci_pll_probe,
925 	.driver		= {
926 		.name		= "davinci-pll-clk",
927 		.of_match_table	= davinci_pll_of_match,
928 	},
929 	.id_table	= davinci_pll_id_table,
930 };
931 
932 static int __init davinci_pll_driver_init(void)
933 {
934 	return platform_driver_register(&davinci_pll_driver);
935 }
936 
937 /* has to be postcore_initcall because PSC devices depend on PLL parent clocks */
938 postcore_initcall(davinci_pll_driver_init);
939 
940 #ifdef CONFIG_DEBUG_FS
941 #include <linux/debugfs.h>
942 
943 #define DEBUG_REG(n)	\
944 {			\
945 	.name	= #n,	\
946 	.offset	= n,	\
947 }
948 
949 static const struct debugfs_reg32 davinci_pll_regs[] = {
950 	DEBUG_REG(REVID),
951 	DEBUG_REG(PLLCTL),
952 	DEBUG_REG(OCSEL),
953 	DEBUG_REG(PLLSECCTL),
954 	DEBUG_REG(PLLM),
955 	DEBUG_REG(PREDIV),
956 	DEBUG_REG(PLLDIV1),
957 	DEBUG_REG(PLLDIV2),
958 	DEBUG_REG(PLLDIV3),
959 	DEBUG_REG(OSCDIV),
960 	DEBUG_REG(POSTDIV),
961 	DEBUG_REG(BPDIV),
962 	DEBUG_REG(PLLCMD),
963 	DEBUG_REG(PLLSTAT),
964 	DEBUG_REG(ALNCTL),
965 	DEBUG_REG(DCHANGE),
966 	DEBUG_REG(CKEN),
967 	DEBUG_REG(CKSTAT),
968 	DEBUG_REG(SYSTAT),
969 	DEBUG_REG(PLLDIV4),
970 	DEBUG_REG(PLLDIV5),
971 	DEBUG_REG(PLLDIV6),
972 	DEBUG_REG(PLLDIV7),
973 	DEBUG_REG(PLLDIV8),
974 	DEBUG_REG(PLLDIV9),
975 };
976 
977 static void davinci_pll_debug_init(struct clk_hw *hw, struct dentry *dentry)
978 {
979 	struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
980 	struct debugfs_regset32 *regset;
981 
982 	regset = kzalloc(sizeof(*regset), GFP_KERNEL);
983 	if (!regset)
984 		return;
985 
986 	regset->regs = davinci_pll_regs;
987 	regset->nregs = ARRAY_SIZE(davinci_pll_regs);
988 	regset->base = pll->base;
989 
990 	debugfs_create_regset32("registers", 0400, dentry, regset);
991 }
992 #endif
993