1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * R-Car Gen3 Clock Pulse Generator
4  *
5  * Copyright (C) 2015-2018 Glider bvba
6  * Copyright (C) 2019 Renesas Electronics Corp.
7  *
8  * Based on clk-rcar-gen3.c
9  *
10  * Copyright (C) 2015 Renesas Electronics Corp.
11  */
12 
13 #include <linux/bug.h>
14 #include <linux/bitfield.h>
15 #include <linux/clk.h>
16 #include <linux/clk-provider.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/io.h>
21 #include <linux/pm.h>
22 #include <linux/slab.h>
23 #include <linux/sys_soc.h>
24 
25 #include "renesas-cpg-mssr.h"
26 #include "rcar-cpg-lib.h"
27 #include "rcar-gen3-cpg.h"
28 
29 #define CPG_PLLECR		0x00d0	/* PLL Enable Control Register */
30 
31 #define CPG_PLLECR_PLLST(n)	BIT(8 + (n))	/* PLLn Circuit Status */
32 
33 #define CPG_PLL0CR		0x00d8	/* PLLn Control Registers */
34 #define CPG_PLL2CR		0x002c
35 #define CPG_PLL4CR		0x01f4
36 
37 #define CPG_PLLnCR_STC_MASK	GENMASK(30, 24)	/* PLL Circuit Mult. Ratio */
38 
39 #define CPG_RCKCR_CKSEL	BIT(15)	/* RCLK Clock Source Select */
40 
41 /* PLL Clocks */
42 struct cpg_pll_clk {
43 	struct clk_hw hw;
44 	void __iomem *pllcr_reg;
45 	void __iomem *pllecr_reg;
46 	unsigned int fixed_mult;
47 	u32 pllecr_pllst_mask;
48 };
49 
50 #define to_pll_clk(_hw)   container_of(_hw, struct cpg_pll_clk, hw)
51 
cpg_pll_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)52 static unsigned long cpg_pll_clk_recalc_rate(struct clk_hw *hw,
53 					     unsigned long parent_rate)
54 {
55 	struct cpg_pll_clk *pll_clk = to_pll_clk(hw);
56 	unsigned int mult;
57 	u32 val;
58 
59 	val = readl(pll_clk->pllcr_reg) & CPG_PLLnCR_STC_MASK;
60 	mult = (val >> __ffs(CPG_PLLnCR_STC_MASK)) + 1;
61 
62 	return parent_rate * mult * pll_clk->fixed_mult;
63 }
64 
cpg_pll_clk_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)65 static int cpg_pll_clk_determine_rate(struct clk_hw *hw,
66 				      struct clk_rate_request *req)
67 {
68 	struct cpg_pll_clk *pll_clk = to_pll_clk(hw);
69 	unsigned int min_mult, max_mult, mult;
70 	unsigned long prate;
71 
72 	prate = req->best_parent_rate * pll_clk->fixed_mult;
73 	min_mult = max(div64_ul(req->min_rate, prate), 1ULL);
74 	max_mult = min(div64_ul(req->max_rate, prate), 128ULL);
75 	if (max_mult < min_mult)
76 		return -EINVAL;
77 
78 	mult = DIV_ROUND_CLOSEST_ULL(req->rate, prate);
79 	mult = clamp(mult, min_mult, max_mult);
80 
81 	req->rate = prate * mult;
82 	return 0;
83 }
84 
cpg_pll_clk_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)85 static int cpg_pll_clk_set_rate(struct clk_hw *hw, unsigned long rate,
86 				unsigned long parent_rate)
87 {
88 	struct cpg_pll_clk *pll_clk = to_pll_clk(hw);
89 	unsigned int mult, i;
90 	u32 val;
91 
92 	mult = DIV_ROUND_CLOSEST_ULL(rate, parent_rate * pll_clk->fixed_mult);
93 	mult = clamp(mult, 1U, 128U);
94 
95 	val = readl(pll_clk->pllcr_reg);
96 	val &= ~CPG_PLLnCR_STC_MASK;
97 	val |= (mult - 1) << __ffs(CPG_PLLnCR_STC_MASK);
98 	writel(val, pll_clk->pllcr_reg);
99 
100 	for (i = 1000; i; i--) {
101 		if (readl(pll_clk->pllecr_reg) & pll_clk->pllecr_pllst_mask)
102 			return 0;
103 
104 		cpu_relax();
105 	}
106 
107 	return -ETIMEDOUT;
108 }
109 
110 static const struct clk_ops cpg_pll_clk_ops = {
111 	.recalc_rate = cpg_pll_clk_recalc_rate,
112 	.determine_rate = cpg_pll_clk_determine_rate,
113 	.set_rate = cpg_pll_clk_set_rate,
114 };
115 
cpg_pll_clk_register(const char * name,const char * parent_name,void __iomem * base,unsigned int mult,unsigned int offset,unsigned int index)116 static struct clk * __init cpg_pll_clk_register(const char *name,
117 						const char *parent_name,
118 						void __iomem *base,
119 						unsigned int mult,
120 						unsigned int offset,
121 						unsigned int index)
122 
123 {
124 	struct cpg_pll_clk *pll_clk;
125 	struct clk_init_data init = {};
126 	struct clk *clk;
127 
128 	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
129 	if (!pll_clk)
130 		return ERR_PTR(-ENOMEM);
131 
132 	init.name = name;
133 	init.ops = &cpg_pll_clk_ops;
134 	init.parent_names = &parent_name;
135 	init.num_parents = 1;
136 
137 	pll_clk->hw.init = &init;
138 	pll_clk->pllcr_reg = base + offset;
139 	pll_clk->pllecr_reg = base + CPG_PLLECR;
140 	pll_clk->fixed_mult = mult;	/* PLL refclk x (setting + 1) x mult */
141 	pll_clk->pllecr_pllst_mask = CPG_PLLECR_PLLST(index);
142 
143 	clk = clk_register(NULL, &pll_clk->hw);
144 	if (IS_ERR(clk))
145 		kfree(pll_clk);
146 
147 	return clk;
148 }
149 
150 /*
151  * Z Clock & Z2 Clock
152  *
153  * Traits of this clock:
154  * prepare - clk_prepare only ensures that parents are prepared
155  * enable - clk_enable only ensures that parents are enabled
156  * rate - rate is adjustable.
157  *        clk->rate = (parent->rate * mult / 32 ) / fixed_div
158  * parent - fixed parent.  No clk_set_parent support
159  */
160 #define CPG_FRQCRB			0x00000004
161 #define CPG_FRQCRB_KICK			BIT(31)
162 #define CPG_FRQCRC			0x000000e0
163 
164 struct cpg_z_clk {
165 	struct clk_hw hw;
166 	void __iomem *reg;
167 	void __iomem *kick_reg;
168 	unsigned long max_rate;		/* Maximum rate for normal mode */
169 	unsigned int fixed_div;
170 	u32 mask;
171 };
172 
173 #define to_z_clk(_hw)	container_of(_hw, struct cpg_z_clk, hw)
174 
cpg_z_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)175 static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
176 					   unsigned long parent_rate)
177 {
178 	struct cpg_z_clk *zclk = to_z_clk(hw);
179 	unsigned int mult;
180 	u32 val;
181 
182 	val = readl(zclk->reg) & zclk->mask;
183 	mult = 32 - (val >> __ffs(zclk->mask));
184 
185 	return DIV_ROUND_CLOSEST_ULL((u64)parent_rate * mult,
186 				     32 * zclk->fixed_div);
187 }
188 
cpg_z_clk_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)189 static int cpg_z_clk_determine_rate(struct clk_hw *hw,
190 				    struct clk_rate_request *req)
191 {
192 	struct cpg_z_clk *zclk = to_z_clk(hw);
193 	unsigned int min_mult, max_mult, mult;
194 	unsigned long rate, prate;
195 
196 	rate = min(req->rate, req->max_rate);
197 	if (rate <= zclk->max_rate) {
198 		/* Set parent rate to initial value for normal modes */
199 		prate = zclk->max_rate;
200 	} else {
201 		/* Set increased parent rate for boost modes */
202 		prate = rate;
203 	}
204 	req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
205 						  prate * zclk->fixed_div);
206 
207 	prate = req->best_parent_rate / zclk->fixed_div;
208 	min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL);
209 	max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL);
210 	if (max_mult < min_mult)
211 		return -EINVAL;
212 
213 	mult = DIV_ROUND_CLOSEST_ULL(rate * 32ULL, prate);
214 	mult = clamp(mult, min_mult, max_mult);
215 
216 	req->rate = DIV_ROUND_CLOSEST_ULL((u64)prate * mult, 32);
217 	return 0;
218 }
219 
cpg_z_clk_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)220 static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
221 			      unsigned long parent_rate)
222 {
223 	struct cpg_z_clk *zclk = to_z_clk(hw);
224 	unsigned int mult;
225 	unsigned int i;
226 
227 	mult = DIV64_U64_ROUND_CLOSEST(rate * 32ULL * zclk->fixed_div,
228 				       parent_rate);
229 	mult = clamp(mult, 1U, 32U);
230 
231 	if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
232 		return -EBUSY;
233 
234 	cpg_reg_modify(zclk->reg, zclk->mask, (32 - mult) << __ffs(zclk->mask));
235 
236 	/*
237 	 * Set KICK bit in FRQCRB to update hardware setting and wait for
238 	 * clock change completion.
239 	 */
240 	cpg_reg_modify(zclk->kick_reg, 0, CPG_FRQCRB_KICK);
241 
242 	/*
243 	 * Note: There is no HW information about the worst case latency.
244 	 *
245 	 * Using experimental measurements, it seems that no more than
246 	 * ~10 iterations are needed, independently of the CPU rate.
247 	 * Since this value might be dependent on external xtal rate, pll1
248 	 * rate or even the other emulation clocks rate, use 1000 as a
249 	 * "super" safe value.
250 	 */
251 	for (i = 1000; i; i--) {
252 		if (!(readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
253 			return 0;
254 
255 		cpu_relax();
256 	}
257 
258 	return -ETIMEDOUT;
259 }
260 
261 static const struct clk_ops cpg_z_clk_ops = {
262 	.recalc_rate = cpg_z_clk_recalc_rate,
263 	.determine_rate = cpg_z_clk_determine_rate,
264 	.set_rate = cpg_z_clk_set_rate,
265 };
266 
cpg_z_clk_register(const char * name,const char * parent_name,void __iomem * reg,unsigned int div,unsigned int offset)267 static struct clk * __init cpg_z_clk_register(const char *name,
268 					      const char *parent_name,
269 					      void __iomem *reg,
270 					      unsigned int div,
271 					      unsigned int offset)
272 {
273 	struct clk_init_data init = {};
274 	struct cpg_z_clk *zclk;
275 	struct clk *clk;
276 
277 	zclk = kzalloc(sizeof(*zclk), GFP_KERNEL);
278 	if (!zclk)
279 		return ERR_PTR(-ENOMEM);
280 
281 	init.name = name;
282 	init.ops = &cpg_z_clk_ops;
283 	init.flags = CLK_SET_RATE_PARENT;
284 	init.parent_names = &parent_name;
285 	init.num_parents = 1;
286 
287 	zclk->reg = reg + CPG_FRQCRC;
288 	zclk->kick_reg = reg + CPG_FRQCRB;
289 	zclk->hw.init = &init;
290 	zclk->mask = GENMASK(offset + 4, offset);
291 	zclk->fixed_div = div; /* PLLVCO x 1/div x SYS-CPU divider */
292 
293 	clk = clk_register(NULL, &zclk->hw);
294 	if (IS_ERR(clk)) {
295 		kfree(zclk);
296 		return clk;
297 	}
298 
299 	zclk->max_rate = clk_hw_get_rate(clk_hw_get_parent(&zclk->hw)) /
300 			 zclk->fixed_div;
301 	return clk;
302 }
303 
304 static const struct clk_div_table cpg_rpcsrc_div_table[] = {
305 	{ 2, 5 }, { 3, 6 }, { 0, 0 },
306 };
307 
308 static const struct rcar_gen3_cpg_pll_config *cpg_pll_config __initdata;
309 static unsigned int cpg_clk_extalr __initdata;
310 static u32 cpg_mode __initdata;
311 static u32 cpg_quirks __initdata;
312 
313 #define PLL_ERRATA	BIT(0)		/* Missing PLL0/2/4 post-divider */
314 #define RCKCR_CKSEL	BIT(1)		/* Manual RCLK parent selection */
315 #define SD_SKIP_FIRST	BIT(2)		/* Skip first clock in SD table */
316 
317 
318 static const struct soc_device_attribute cpg_quirks_match[] __initconst = {
319 	{
320 		.soc_id = "r8a7795", .revision = "ES1.0",
321 		.data = (void *)(PLL_ERRATA | RCKCR_CKSEL | SD_SKIP_FIRST),
322 	},
323 	{
324 		.soc_id = "r8a7795", .revision = "ES1.*",
325 		.data = (void *)(RCKCR_CKSEL | SD_SKIP_FIRST),
326 	},
327 	{
328 		.soc_id = "r8a7795", .revision = "ES2.0",
329 		.data = (void *)SD_SKIP_FIRST,
330 	},
331 	{
332 		.soc_id = "r8a7796", .revision = "ES1.0",
333 		.data = (void *)(RCKCR_CKSEL | SD_SKIP_FIRST),
334 	},
335 	{
336 		.soc_id = "r8a7796", .revision = "ES1.1",
337 		.data = (void *)SD_SKIP_FIRST,
338 	},
339 	{ /* sentinel */ }
340 };
341 
rcar_gen3_cpg_clk_register(struct device * dev,const struct cpg_core_clk * core,const struct cpg_mssr_info * info,struct clk ** clks,void __iomem * base,struct raw_notifier_head * notifiers)342 struct clk * __init rcar_gen3_cpg_clk_register(struct device *dev,
343 	const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
344 	struct clk **clks, void __iomem *base,
345 	struct raw_notifier_head *notifiers)
346 {
347 	const struct clk *parent;
348 	unsigned int mult = 1;
349 	unsigned int div = 1;
350 	u32 value;
351 
352 	parent = clks[core->parent & 0xffff];	/* some types use high bits */
353 	if (IS_ERR(parent))
354 		return ERR_CAST(parent);
355 
356 	switch (core->type) {
357 	case CLK_TYPE_GEN3_MAIN:
358 		div = cpg_pll_config->extal_div;
359 		break;
360 
361 	case CLK_TYPE_GEN3_PLL0:
362 		/*
363 		 * PLL0 is implemented as a custom clock, to change the
364 		 * multiplier when cpufreq changes between normal and boost
365 		 * modes.
366 		 */
367 		mult = (cpg_quirks & PLL_ERRATA) ? 4 : 2;
368 		return cpg_pll_clk_register(core->name, __clk_get_name(parent),
369 					    base, mult, CPG_PLL0CR, 0);
370 
371 	case CLK_TYPE_GEN3_PLL1:
372 		mult = cpg_pll_config->pll1_mult;
373 		div = cpg_pll_config->pll1_div;
374 		break;
375 
376 	case CLK_TYPE_GEN3_PLL2:
377 		/*
378 		 * PLL2 is implemented as a custom clock, to change the
379 		 * multiplier when cpufreq changes between normal and boost
380 		 * modes.
381 		 */
382 		mult = (cpg_quirks & PLL_ERRATA) ? 4 : 2;
383 		return cpg_pll_clk_register(core->name, __clk_get_name(parent),
384 					    base, mult, CPG_PLL2CR, 2);
385 
386 	case CLK_TYPE_GEN3_PLL3:
387 		mult = cpg_pll_config->pll3_mult;
388 		div = cpg_pll_config->pll3_div;
389 		break;
390 
391 	case CLK_TYPE_GEN3_PLL4:
392 		/*
393 		 * PLL4 is a configurable multiplier clock. Register it as a
394 		 * fixed factor clock for now as there's no generic multiplier
395 		 * clock implementation and we currently have no need to change
396 		 * the multiplier value.
397 		 */
398 		value = readl(base + CPG_PLL4CR);
399 		mult = (((value >> 24) & 0x7f) + 1) * 2;
400 		if (cpg_quirks & PLL_ERRATA)
401 			mult *= 2;
402 		break;
403 
404 	case CLK_TYPE_GEN3_SD:
405 		return cpg_sd_clk_register(core->name, base, core->offset,
406 					   __clk_get_name(parent), notifiers,
407 					   cpg_quirks & SD_SKIP_FIRST);
408 
409 	case CLK_TYPE_GEN3_R:
410 		if (cpg_quirks & RCKCR_CKSEL) {
411 			struct cpg_simple_notifier *csn;
412 
413 			csn = kzalloc(sizeof(*csn), GFP_KERNEL);
414 			if (!csn)
415 				return ERR_PTR(-ENOMEM);
416 
417 			csn->reg = base + CPG_RCKCR;
418 
419 			/*
420 			 * RINT is default.
421 			 * Only if EXTALR is populated, we switch to it.
422 			 */
423 			value = readl(csn->reg) & 0x3f;
424 
425 			if (clk_get_rate(clks[cpg_clk_extalr])) {
426 				parent = clks[cpg_clk_extalr];
427 				value |= CPG_RCKCR_CKSEL;
428 			}
429 
430 			writel(value, csn->reg);
431 			cpg_simple_notifier_register(notifiers, csn);
432 			break;
433 		}
434 
435 		/* Select parent clock of RCLK by MD28 */
436 		if (cpg_mode & BIT(28))
437 			parent = clks[cpg_clk_extalr];
438 		break;
439 
440 	case CLK_TYPE_GEN3_MDSEL:
441 		/*
442 		 * Clock selectable between two parents and two fixed dividers
443 		 * using a mode pin
444 		 */
445 		if (cpg_mode & BIT(core->offset)) {
446 			div = core->div & 0xffff;
447 		} else {
448 			parent = clks[core->parent >> 16];
449 			if (IS_ERR(parent))
450 				return ERR_CAST(parent);
451 			div = core->div >> 16;
452 		}
453 		mult = 1;
454 		break;
455 
456 	case CLK_TYPE_GEN3_Z:
457 		return cpg_z_clk_register(core->name, __clk_get_name(parent),
458 					  base, core->div, core->offset);
459 
460 	case CLK_TYPE_GEN3_OSC:
461 		/*
462 		 * Clock combining OSC EXTAL predivider and a fixed divider
463 		 */
464 		div = cpg_pll_config->osc_prediv * core->div;
465 		break;
466 
467 	case CLK_TYPE_GEN3_RCKSEL:
468 		/*
469 		 * Clock selectable between two parents and two fixed dividers
470 		 * using RCKCR.CKSEL
471 		 */
472 		if (readl(base + CPG_RCKCR) & CPG_RCKCR_CKSEL) {
473 			div = core->div & 0xffff;
474 		} else {
475 			parent = clks[core->parent >> 16];
476 			if (IS_ERR(parent))
477 				return ERR_CAST(parent);
478 			div = core->div >> 16;
479 		}
480 		break;
481 
482 	case CLK_TYPE_GEN3_RPCSRC:
483 		return clk_register_divider_table(NULL, core->name,
484 						  __clk_get_name(parent), 0,
485 						  base + CPG_RPCCKCR, 3, 2, 0,
486 						  cpg_rpcsrc_div_table,
487 						  &cpg_lock);
488 
489 	case CLK_TYPE_GEN3_E3_RPCSRC:
490 		/*
491 		 * Register RPCSRC as fixed factor clock based on the
492 		 * MD[4:1] pins and CPG_RPCCKCR[4:3] register value for
493 		 * which has been set prior to booting the kernel.
494 		 */
495 		value = (readl(base + CPG_RPCCKCR) & GENMASK(4, 3)) >> 3;
496 
497 		switch (value) {
498 		case 0:
499 			div = 5;
500 			break;
501 		case 1:
502 			div = 3;
503 			break;
504 		case 2:
505 			parent = clks[core->parent >> 16];
506 			if (IS_ERR(parent))
507 				return ERR_CAST(parent);
508 			div = core->div;
509 			break;
510 		case 3:
511 		default:
512 			div = 2;
513 			break;
514 		}
515 		break;
516 
517 	case CLK_TYPE_GEN3_RPC:
518 		return cpg_rpc_clk_register(core->name, base + CPG_RPCCKCR,
519 					    __clk_get_name(parent), notifiers);
520 
521 	case CLK_TYPE_GEN3_RPCD2:
522 		return cpg_rpcd2_clk_register(core->name, base + CPG_RPCCKCR,
523 					      __clk_get_name(parent));
524 
525 	default:
526 		return ERR_PTR(-EINVAL);
527 	}
528 
529 	return clk_register_fixed_factor(NULL, core->name,
530 					 __clk_get_name(parent), 0, mult, div);
531 }
532 
rcar_gen3_cpg_init(const struct rcar_gen3_cpg_pll_config * config,unsigned int clk_extalr,u32 mode)533 int __init rcar_gen3_cpg_init(const struct rcar_gen3_cpg_pll_config *config,
534 			      unsigned int clk_extalr, u32 mode)
535 {
536 	const struct soc_device_attribute *attr;
537 
538 	cpg_pll_config = config;
539 	cpg_clk_extalr = clk_extalr;
540 	cpg_mode = mode;
541 	attr = soc_device_match(cpg_quirks_match);
542 	if (attr)
543 		cpg_quirks = (uintptr_t)attr->data;
544 	pr_debug("%s: mode = 0x%x quirks = 0x%x\n", __func__, mode, cpg_quirks);
545 
546 	spin_lock_init(&cpg_lock);
547 
548 	return 0;
549 }
550