xref: /openbmc/linux/drivers/clk/rockchip/clk-pll.c (revision 9cfc5c90)
1 /*
2  * Copyright (c) 2014 MundoReader S.L.
3  * Author: Heiko Stuebner <heiko@sntech.de>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <asm/div64.h>
17 #include <linux/slab.h>
18 #include <linux/io.h>
19 #include <linux/delay.h>
20 #include <linux/clk-provider.h>
21 #include <linux/regmap.h>
22 #include "clk.h"
23 
24 #define PLL_MODE_MASK		0x3
25 #define PLL_MODE_SLOW		0x0
26 #define PLL_MODE_NORM		0x1
27 #define PLL_MODE_DEEP		0x2
28 
29 struct rockchip_clk_pll {
30 	struct clk_hw		hw;
31 
32 	struct clk_mux		pll_mux;
33 	const struct clk_ops	*pll_mux_ops;
34 
35 	struct notifier_block	clk_nb;
36 
37 	void __iomem		*reg_base;
38 	int			lock_offset;
39 	unsigned int		lock_shift;
40 	enum rockchip_pll_type	type;
41 	u8			flags;
42 	const struct rockchip_pll_rate_table *rate_table;
43 	unsigned int		rate_count;
44 	spinlock_t		*lock;
45 };
46 
47 #define to_rockchip_clk_pll(_hw) container_of(_hw, struct rockchip_clk_pll, hw)
48 #define to_rockchip_clk_pll_nb(nb) \
49 			container_of(nb, struct rockchip_clk_pll, clk_nb)
50 
51 static const struct rockchip_pll_rate_table *rockchip_get_pll_settings(
52 			    struct rockchip_clk_pll *pll, unsigned long rate)
53 {
54 	const struct rockchip_pll_rate_table  *rate_table = pll->rate_table;
55 	int i;
56 
57 	for (i = 0; i < pll->rate_count; i++) {
58 		if (rate == rate_table[i].rate)
59 			return &rate_table[i];
60 	}
61 
62 	return NULL;
63 }
64 
65 static long rockchip_pll_round_rate(struct clk_hw *hw,
66 			    unsigned long drate, unsigned long *prate)
67 {
68 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
69 	const struct rockchip_pll_rate_table *rate_table = pll->rate_table;
70 	int i;
71 
72 	/* Assumming rate_table is in descending order */
73 	for (i = 0; i < pll->rate_count; i++) {
74 		if (drate >= rate_table[i].rate)
75 			return rate_table[i].rate;
76 	}
77 
78 	/* return minimum supported value */
79 	return rate_table[i - 1].rate;
80 }
81 
82 /*
83  * Wait for the pll to reach the locked state.
84  * The calling set_rate function is responsible for making sure the
85  * grf regmap is available.
86  */
87 static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll)
88 {
89 	struct regmap *grf = rockchip_clk_get_grf();
90 	unsigned int val;
91 	int delay = 24000000, ret;
92 
93 	while (delay > 0) {
94 		ret = regmap_read(grf, pll->lock_offset, &val);
95 		if (ret) {
96 			pr_err("%s: failed to read pll lock status: %d\n",
97 			       __func__, ret);
98 			return ret;
99 		}
100 
101 		if (val & BIT(pll->lock_shift))
102 			return 0;
103 		delay--;
104 	}
105 
106 	pr_err("%s: timeout waiting for pll to lock\n", __func__);
107 	return -ETIMEDOUT;
108 }
109 
110 /**
111  * PLL used in RK3066, RK3188 and RK3288
112  */
113 
114 #define RK3066_PLL_RESET_DELAY(nr)	((nr * 500) / 24 + 1)
115 
116 #define RK3066_PLLCON(i)		(i * 0x4)
117 #define RK3066_PLLCON0_OD_MASK		0xf
118 #define RK3066_PLLCON0_OD_SHIFT		0
119 #define RK3066_PLLCON0_NR_MASK		0x3f
120 #define RK3066_PLLCON0_NR_SHIFT		8
121 #define RK3066_PLLCON1_NF_MASK		0x1fff
122 #define RK3066_PLLCON1_NF_SHIFT		0
123 #define RK3066_PLLCON2_NB_MASK		0xfff
124 #define RK3066_PLLCON2_NB_SHIFT		0
125 #define RK3066_PLLCON3_RESET		(1 << 5)
126 #define RK3066_PLLCON3_PWRDOWN		(1 << 1)
127 #define RK3066_PLLCON3_BYPASS		(1 << 0)
128 
129 static void rockchip_rk3066_pll_get_params(struct rockchip_clk_pll *pll,
130 					struct rockchip_pll_rate_table *rate)
131 {
132 	u32 pllcon;
133 
134 	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0));
135 	rate->nr = ((pllcon >> RK3066_PLLCON0_NR_SHIFT)
136 				& RK3066_PLLCON0_NR_MASK) + 1;
137 	rate->no = ((pllcon >> RK3066_PLLCON0_OD_SHIFT)
138 				& RK3066_PLLCON0_OD_MASK) + 1;
139 
140 	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1));
141 	rate->nf = ((pllcon >> RK3066_PLLCON1_NF_SHIFT)
142 				& RK3066_PLLCON1_NF_MASK) + 1;
143 
144 	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(2));
145 	rate->nb = ((pllcon >> RK3066_PLLCON2_NB_SHIFT)
146 				& RK3066_PLLCON2_NB_MASK) + 1;
147 }
148 
149 static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw,
150 						     unsigned long prate)
151 {
152 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
153 	struct rockchip_pll_rate_table cur;
154 	u64 rate64 = prate;
155 	u32 pllcon;
156 
157 	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(3));
158 	if (pllcon & RK3066_PLLCON3_BYPASS) {
159 		pr_debug("%s: pll %s is bypassed\n", __func__,
160 			clk_hw_get_name(hw));
161 		return prate;
162 	}
163 
164 	rockchip_rk3066_pll_get_params(pll, &cur);
165 
166 	rate64 *= cur.nf;
167 	do_div(rate64, cur.nr);
168 	do_div(rate64, cur.no);
169 
170 	return (unsigned long)rate64;
171 }
172 
173 static int rockchip_rk3066_pll_set_params(struct rockchip_clk_pll *pll,
174 				const struct rockchip_pll_rate_table *rate)
175 {
176 	const struct clk_ops *pll_mux_ops = pll->pll_mux_ops;
177 	struct clk_mux *pll_mux = &pll->pll_mux;
178 	struct rockchip_pll_rate_table cur;
179 	int rate_change_remuxed = 0;
180 	int cur_parent;
181 	int ret;
182 
183 	pr_debug("%s: rate settings for %lu (nr, no, nf): (%d, %d, %d)\n",
184 		 __func__, rate->rate, rate->nr, rate->no, rate->nf);
185 
186 	rockchip_rk3066_pll_get_params(pll, &cur);
187 	cur.rate = 0;
188 
189 	cur_parent = pll_mux_ops->get_parent(&pll_mux->hw);
190 	if (cur_parent == PLL_MODE_NORM) {
191 		pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_SLOW);
192 		rate_change_remuxed = 1;
193 	}
194 
195 	/* enter reset mode */
196 	writel(HIWORD_UPDATE(RK3066_PLLCON3_RESET, RK3066_PLLCON3_RESET, 0),
197 	       pll->reg_base + RK3066_PLLCON(3));
198 
199 	/* update pll values */
200 	writel(HIWORD_UPDATE(rate->nr - 1, RK3066_PLLCON0_NR_MASK,
201 					   RK3066_PLLCON0_NR_SHIFT) |
202 	       HIWORD_UPDATE(rate->no - 1, RK3066_PLLCON0_OD_MASK,
203 					   RK3066_PLLCON0_OD_SHIFT),
204 	       pll->reg_base + RK3066_PLLCON(0));
205 
206 	writel_relaxed(HIWORD_UPDATE(rate->nf - 1, RK3066_PLLCON1_NF_MASK,
207 						   RK3066_PLLCON1_NF_SHIFT),
208 		       pll->reg_base + RK3066_PLLCON(1));
209 	writel_relaxed(HIWORD_UPDATE(rate->nb - 1, RK3066_PLLCON2_NB_MASK,
210 						   RK3066_PLLCON2_NB_SHIFT),
211 		       pll->reg_base + RK3066_PLLCON(2));
212 
213 	/* leave reset and wait the reset_delay */
214 	writel(HIWORD_UPDATE(0, RK3066_PLLCON3_RESET, 0),
215 	       pll->reg_base + RK3066_PLLCON(3));
216 	udelay(RK3066_PLL_RESET_DELAY(rate->nr));
217 
218 	/* wait for the pll to lock */
219 	ret = rockchip_pll_wait_lock(pll);
220 	if (ret) {
221 		pr_warn("%s: pll update unsucessful, trying to restore old params\n",
222 			__func__);
223 		rockchip_rk3066_pll_set_params(pll, &cur);
224 	}
225 
226 	if (rate_change_remuxed)
227 		pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_NORM);
228 
229 	return ret;
230 }
231 
232 static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate,
233 					unsigned long prate)
234 {
235 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
236 	const struct rockchip_pll_rate_table *rate;
237 	unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate);
238 	struct regmap *grf = rockchip_clk_get_grf();
239 
240 	if (IS_ERR(grf)) {
241 		pr_debug("%s: grf regmap not available, aborting rate change\n",
242 			 __func__);
243 		return PTR_ERR(grf);
244 	}
245 
246 	pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n",
247 		 __func__, clk_hw_get_name(hw), old_rate, drate, prate);
248 
249 	/* Get required rate settings from table */
250 	rate = rockchip_get_pll_settings(pll, drate);
251 	if (!rate) {
252 		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
253 			drate, clk_hw_get_name(hw));
254 		return -EINVAL;
255 	}
256 
257 	return rockchip_rk3066_pll_set_params(pll, rate);
258 }
259 
260 static int rockchip_rk3066_pll_enable(struct clk_hw *hw)
261 {
262 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
263 
264 	writel(HIWORD_UPDATE(0, RK3066_PLLCON3_PWRDOWN, 0),
265 	       pll->reg_base + RK3066_PLLCON(3));
266 
267 	return 0;
268 }
269 
270 static void rockchip_rk3066_pll_disable(struct clk_hw *hw)
271 {
272 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
273 
274 	writel(HIWORD_UPDATE(RK3066_PLLCON3_PWRDOWN,
275 			     RK3066_PLLCON3_PWRDOWN, 0),
276 	       pll->reg_base + RK3066_PLLCON(3));
277 }
278 
279 static int rockchip_rk3066_pll_is_enabled(struct clk_hw *hw)
280 {
281 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
282 	u32 pllcon = readl(pll->reg_base + RK3066_PLLCON(3));
283 
284 	return !(pllcon & RK3066_PLLCON3_PWRDOWN);
285 }
286 
287 static void rockchip_rk3066_pll_init(struct clk_hw *hw)
288 {
289 	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
290 	const struct rockchip_pll_rate_table *rate;
291 	struct rockchip_pll_rate_table cur;
292 	unsigned long drate;
293 
294 	if (!(pll->flags & ROCKCHIP_PLL_SYNC_RATE))
295 		return;
296 
297 	drate = clk_hw_get_rate(hw);
298 	rate = rockchip_get_pll_settings(pll, drate);
299 
300 	/* when no rate setting for the current rate, rely on clk_set_rate */
301 	if (!rate)
302 		return;
303 
304 	rockchip_rk3066_pll_get_params(pll, &cur);
305 
306 	pr_debug("%s: pll %s@%lu: nr (%d:%d); no (%d:%d); nf(%d:%d), nb(%d:%d)\n",
307 		 __func__, clk_hw_get_name(hw), drate, rate->nr, cur.nr,
308 		 rate->no, cur.no, rate->nf, cur.nf, rate->nb, cur.nb);
309 	if (rate->nr != cur.nr || rate->no != cur.no || rate->nf != cur.nf
310 						     || rate->nb != cur.nb) {
311 		struct regmap *grf = rockchip_clk_get_grf();
312 
313 		if (IS_ERR(grf))
314 			return;
315 
316 		pr_debug("%s: pll %s: rate params do not match rate table, adjusting\n",
317 			 __func__, clk_hw_get_name(hw));
318 		rockchip_rk3066_pll_set_params(pll, rate);
319 	}
320 }
321 
322 static const struct clk_ops rockchip_rk3066_pll_clk_norate_ops = {
323 	.recalc_rate = rockchip_rk3066_pll_recalc_rate,
324 	.enable = rockchip_rk3066_pll_enable,
325 	.disable = rockchip_rk3066_pll_disable,
326 	.is_enabled = rockchip_rk3066_pll_is_enabled,
327 };
328 
329 static const struct clk_ops rockchip_rk3066_pll_clk_ops = {
330 	.recalc_rate = rockchip_rk3066_pll_recalc_rate,
331 	.round_rate = rockchip_pll_round_rate,
332 	.set_rate = rockchip_rk3066_pll_set_rate,
333 	.enable = rockchip_rk3066_pll_enable,
334 	.disable = rockchip_rk3066_pll_disable,
335 	.is_enabled = rockchip_rk3066_pll_is_enabled,
336 	.init = rockchip_rk3066_pll_init,
337 };
338 
339 /*
340  * Common registering of pll clocks
341  */
342 
343 struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
344 		const char *name, const char *const *parent_names,
345 		u8 num_parents, void __iomem *base, int con_offset,
346 		int grf_lock_offset, int lock_shift, int mode_offset,
347 		int mode_shift, struct rockchip_pll_rate_table *rate_table,
348 		u8 clk_pll_flags, spinlock_t *lock)
349 {
350 	const char *pll_parents[3];
351 	struct clk_init_data init;
352 	struct rockchip_clk_pll *pll;
353 	struct clk_mux *pll_mux;
354 	struct clk *pll_clk, *mux_clk;
355 	char pll_name[20];
356 
357 	if (num_parents != 2) {
358 		pr_err("%s: needs two parent clocks\n", __func__);
359 		return ERR_PTR(-EINVAL);
360 	}
361 
362 	/* name the actual pll */
363 	snprintf(pll_name, sizeof(pll_name), "pll_%s", name);
364 
365 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
366 	if (!pll)
367 		return ERR_PTR(-ENOMEM);
368 
369 	/* create the mux on top of the real pll */
370 	pll->pll_mux_ops = &clk_mux_ops;
371 	pll_mux = &pll->pll_mux;
372 	pll_mux->reg = base + mode_offset;
373 	pll_mux->shift = mode_shift;
374 	pll_mux->mask = PLL_MODE_MASK;
375 	pll_mux->flags = 0;
376 	pll_mux->lock = lock;
377 	pll_mux->hw.init = &init;
378 
379 	if (pll_type == pll_rk3066)
380 		pll_mux->flags |= CLK_MUX_HIWORD_MASK;
381 
382 	/* the actual muxing is xin24m, pll-output, xin32k */
383 	pll_parents[0] = parent_names[0];
384 	pll_parents[1] = pll_name;
385 	pll_parents[2] = parent_names[1];
386 
387 	init.name = name;
388 	init.flags = CLK_SET_RATE_PARENT;
389 	init.ops = pll->pll_mux_ops;
390 	init.parent_names = pll_parents;
391 	init.num_parents = ARRAY_SIZE(pll_parents);
392 
393 	mux_clk = clk_register(NULL, &pll_mux->hw);
394 	if (IS_ERR(mux_clk))
395 		goto err_mux;
396 
397 	/* now create the actual pll */
398 	init.name = pll_name;
399 
400 	/* keep all plls untouched for now */
401 	init.flags = CLK_IGNORE_UNUSED;
402 
403 	init.parent_names = &parent_names[0];
404 	init.num_parents = 1;
405 
406 	if (rate_table) {
407 		int len;
408 
409 		/* find count of rates in rate_table */
410 		for (len = 0; rate_table[len].rate != 0; )
411 			len++;
412 
413 		pll->rate_count = len;
414 		pll->rate_table = kmemdup(rate_table,
415 					pll->rate_count *
416 					sizeof(struct rockchip_pll_rate_table),
417 					GFP_KERNEL);
418 		WARN(!pll->rate_table,
419 			"%s: could not allocate rate table for %s\n",
420 			__func__, name);
421 	}
422 
423 	switch (pll_type) {
424 	case pll_rk3066:
425 		if (!pll->rate_table)
426 			init.ops = &rockchip_rk3066_pll_clk_norate_ops;
427 		else
428 			init.ops = &rockchip_rk3066_pll_clk_ops;
429 		break;
430 	default:
431 		pr_warn("%s: Unknown pll type for pll clk %s\n",
432 			__func__, name);
433 	}
434 
435 	pll->hw.init = &init;
436 	pll->type = pll_type;
437 	pll->reg_base = base + con_offset;
438 	pll->lock_offset = grf_lock_offset;
439 	pll->lock_shift = lock_shift;
440 	pll->flags = clk_pll_flags;
441 	pll->lock = lock;
442 
443 	pll_clk = clk_register(NULL, &pll->hw);
444 	if (IS_ERR(pll_clk)) {
445 		pr_err("%s: failed to register pll clock %s : %ld\n",
446 			__func__, name, PTR_ERR(pll_clk));
447 		goto err_pll;
448 	}
449 
450 	return mux_clk;
451 
452 err_pll:
453 	clk_unregister(mux_clk);
454 	mux_clk = pll_clk;
455 err_mux:
456 	kfree(pll);
457 	return mux_clk;
458 }
459