xref: /linux/drivers/clk/mediatek/clk-pll.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014 MediaTek Inc.
4  * Author: James Liao <jamesjj.liao@mediatek.com>
5  */
6 
7 #include <linux/clk-provider.h>
8 #include <linux/container_of.h>
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of_address.h>
14 #include <linux/slab.h>
15 
16 #include "clk-pll.h"
17 
18 #define MHZ			(1000 * 1000)
19 
20 #define REG_CON0		0
21 #define REG_CON1		4
22 
23 #define CON0_BASE_EN		BIT(0)
24 #define CON0_PWR_ON		BIT(0)
25 #define CON0_ISO_EN		BIT(1)
26 #define PCW_CHG_BIT		31
27 
28 #define AUDPLL_TUNER_EN		BIT(31)
29 
30 /* default 7 bits integer, can be overridden with pcwibits. */
31 #define INTEGER_BITS		7
32 
33 int mtk_pll_is_prepared(struct clk_hw *hw)
34 {
35 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
36 
37 	return (readl(pll->en_addr) & BIT(pll->data->pll_en_bit)) != 0;
38 }
39 
40 static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
41 		u32 pcw, int postdiv)
42 {
43 	int pcwbits = pll->data->pcwbits;
44 	int pcwfbits = 0;
45 	int ibits;
46 	u64 vco;
47 	u8 c = 0;
48 
49 	/* The fractional part of the PLL divider. */
50 	ibits = pll->data->pcwibits ? pll->data->pcwibits : INTEGER_BITS;
51 	if (pcwbits > ibits)
52 		pcwfbits = pcwbits - ibits;
53 
54 	vco = (u64)fin * pcw;
55 
56 	if (pcwfbits && (vco & GENMASK(pcwfbits - 1, 0)))
57 		c = 1;
58 
59 	vco >>= pcwfbits;
60 
61 	if (c)
62 		vco++;
63 
64 	return ((unsigned long)vco + postdiv - 1) / postdiv;
65 }
66 
67 static void __mtk_pll_tuner_enable(struct mtk_clk_pll *pll)
68 {
69 	u32 r;
70 
71 	if (pll->tuner_en_addr) {
72 		r = readl(pll->tuner_en_addr) | BIT(pll->data->tuner_en_bit);
73 		writel(r, pll->tuner_en_addr);
74 	} else if (pll->tuner_addr) {
75 		r = readl(pll->tuner_addr) | AUDPLL_TUNER_EN;
76 		writel(r, pll->tuner_addr);
77 	}
78 }
79 
80 static void __mtk_pll_tuner_disable(struct mtk_clk_pll *pll)
81 {
82 	u32 r;
83 
84 	if (pll->tuner_en_addr) {
85 		r = readl(pll->tuner_en_addr) & ~BIT(pll->data->tuner_en_bit);
86 		writel(r, pll->tuner_en_addr);
87 	} else if (pll->tuner_addr) {
88 		r = readl(pll->tuner_addr) & ~AUDPLL_TUNER_EN;
89 		writel(r, pll->tuner_addr);
90 	}
91 }
92 
93 static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
94 		int postdiv)
95 {
96 	u32 chg, val;
97 
98 	/* disable tuner */
99 	__mtk_pll_tuner_disable(pll);
100 
101 	/* set postdiv */
102 	val = readl(pll->pd_addr);
103 	val &= ~(POSTDIV_MASK << pll->data->pd_shift);
104 	val |= (ffs(postdiv) - 1) << pll->data->pd_shift;
105 
106 	/* postdiv and pcw need to set at the same time if on same register */
107 	if (pll->pd_addr != pll->pcw_addr) {
108 		writel(val, pll->pd_addr);
109 		val = readl(pll->pcw_addr);
110 	}
111 
112 	/* set pcw */
113 	val &= ~GENMASK(pll->data->pcw_shift + pll->data->pcwbits - 1,
114 			pll->data->pcw_shift);
115 	val |= pcw << pll->data->pcw_shift;
116 	writel(val, pll->pcw_addr);
117 	chg = readl(pll->pcw_chg_addr) |
118 	      BIT(pll->data->pcw_chg_bit ? : PCW_CHG_BIT);
119 	writel(chg, pll->pcw_chg_addr);
120 	if (pll->tuner_addr)
121 		writel(val + 1, pll->tuner_addr);
122 
123 	/* restore tuner_en */
124 	__mtk_pll_tuner_enable(pll);
125 
126 	udelay(20);
127 }
128 
129 /*
130  * mtk_pll_calc_values - calculate good values for a given input frequency.
131  * @pll:	The pll
132  * @pcw:	The pcw value (output)
133  * @postdiv:	The post divider (output)
134  * @freq:	The desired target frequency
135  * @fin:	The input frequency
136  *
137  */
138 void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv,
139 			 u32 freq, u32 fin)
140 {
141 	unsigned long fmin = pll->data->fmin ? pll->data->fmin : (1000 * MHZ);
142 	const struct mtk_pll_div_table *div_table = pll->data->div_table;
143 	u64 _pcw;
144 	int ibits;
145 	u32 val;
146 
147 	if (freq > pll->data->fmax)
148 		freq = pll->data->fmax;
149 
150 	if (div_table) {
151 		if (freq > div_table[0].freq)
152 			freq = div_table[0].freq;
153 
154 		for (val = 0; div_table[val + 1].freq != 0; val++) {
155 			if (freq > div_table[val + 1].freq)
156 				break;
157 		}
158 		*postdiv = 1 << val;
159 	} else {
160 		for (val = 0; val < 5; val++) {
161 			*postdiv = 1 << val;
162 			if ((u64)freq * *postdiv >= fmin)
163 				break;
164 		}
165 	}
166 
167 	/* _pcw = freq * postdiv / fin * 2^pcwfbits */
168 	ibits = pll->data->pcwibits ? pll->data->pcwibits : INTEGER_BITS;
169 	_pcw = ((u64)freq << val) << (pll->data->pcwbits - ibits);
170 	do_div(_pcw, fin);
171 
172 	*pcw = (u32)_pcw;
173 }
174 
175 int mtk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
176 		     unsigned long parent_rate)
177 {
178 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
179 	u32 pcw = 0;
180 	u32 postdiv;
181 
182 	mtk_pll_calc_values(pll, &pcw, &postdiv, rate, parent_rate);
183 	mtk_pll_set_rate_regs(pll, pcw, postdiv);
184 
185 	return 0;
186 }
187 
188 unsigned long mtk_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
189 {
190 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
191 	u32 postdiv;
192 	u32 pcw;
193 
194 	postdiv = (readl(pll->pd_addr) >> pll->data->pd_shift) & POSTDIV_MASK;
195 	postdiv = 1 << postdiv;
196 
197 	pcw = readl(pll->pcw_addr) >> pll->data->pcw_shift;
198 	pcw &= GENMASK(pll->data->pcwbits - 1, 0);
199 
200 	return __mtk_pll_recalc_rate(pll, parent_rate, pcw, postdiv);
201 }
202 
203 long mtk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
204 			unsigned long *prate)
205 {
206 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
207 	u32 pcw = 0;
208 	int postdiv;
209 
210 	mtk_pll_calc_values(pll, &pcw, &postdiv, rate, *prate);
211 
212 	return __mtk_pll_recalc_rate(pll, *prate, pcw, postdiv);
213 }
214 
215 int mtk_pll_prepare(struct clk_hw *hw)
216 {
217 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
218 	u32 r;
219 
220 	r = readl(pll->pwr_addr) | CON0_PWR_ON;
221 	writel(r, pll->pwr_addr);
222 	udelay(1);
223 
224 	r = readl(pll->pwr_addr) & ~CON0_ISO_EN;
225 	writel(r, pll->pwr_addr);
226 	udelay(1);
227 
228 	r = readl(pll->en_addr) | BIT(pll->data->pll_en_bit);
229 	writel(r, pll->en_addr);
230 
231 	if (pll->data->en_mask) {
232 		r = readl(pll->base_addr + REG_CON0) | pll->data->en_mask;
233 		writel(r, pll->base_addr + REG_CON0);
234 	}
235 
236 	__mtk_pll_tuner_enable(pll);
237 
238 	udelay(20);
239 
240 	if (pll->data->flags & HAVE_RST_BAR) {
241 		r = readl(pll->base_addr + REG_CON0);
242 		r |= pll->data->rst_bar_mask;
243 		writel(r, pll->base_addr + REG_CON0);
244 	}
245 
246 	return 0;
247 }
248 
249 void mtk_pll_unprepare(struct clk_hw *hw)
250 {
251 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
252 	u32 r;
253 
254 	if (pll->data->flags & HAVE_RST_BAR) {
255 		r = readl(pll->base_addr + REG_CON0);
256 		r &= ~pll->data->rst_bar_mask;
257 		writel(r, pll->base_addr + REG_CON0);
258 	}
259 
260 	__mtk_pll_tuner_disable(pll);
261 
262 	if (pll->data->en_mask) {
263 		r = readl(pll->base_addr + REG_CON0) & ~pll->data->en_mask;
264 		writel(r, pll->base_addr + REG_CON0);
265 	}
266 
267 	r = readl(pll->en_addr) & ~BIT(pll->data->pll_en_bit);
268 	writel(r, pll->en_addr);
269 
270 	r = readl(pll->pwr_addr) | CON0_ISO_EN;
271 	writel(r, pll->pwr_addr);
272 
273 	r = readl(pll->pwr_addr) & ~CON0_PWR_ON;
274 	writel(r, pll->pwr_addr);
275 }
276 
277 const struct clk_ops mtk_pll_ops = {
278 	.is_prepared	= mtk_pll_is_prepared,
279 	.prepare	= mtk_pll_prepare,
280 	.unprepare	= mtk_pll_unprepare,
281 	.recalc_rate	= mtk_pll_recalc_rate,
282 	.round_rate	= mtk_pll_round_rate,
283 	.set_rate	= mtk_pll_set_rate,
284 };
285 
286 struct clk_hw *mtk_clk_register_pll_ops(struct mtk_clk_pll *pll,
287 					const struct mtk_pll_data *data,
288 					void __iomem *base,
289 					const struct clk_ops *pll_ops)
290 {
291 	struct clk_init_data init = {};
292 	int ret;
293 	const char *parent_name = "clk26m";
294 
295 	pll->base_addr = base + data->reg;
296 	pll->pwr_addr = base + data->pwr_reg;
297 	pll->pd_addr = base + data->pd_reg;
298 	pll->pcw_addr = base + data->pcw_reg;
299 	if (data->pcw_chg_reg)
300 		pll->pcw_chg_addr = base + data->pcw_chg_reg;
301 	else
302 		pll->pcw_chg_addr = pll->base_addr + REG_CON1;
303 	if (data->tuner_reg)
304 		pll->tuner_addr = base + data->tuner_reg;
305 	if (data->tuner_en_reg || data->tuner_en_bit)
306 		pll->tuner_en_addr = base + data->tuner_en_reg;
307 	if (data->en_reg)
308 		pll->en_addr = base + data->en_reg;
309 	else
310 		pll->en_addr = pll->base_addr + REG_CON0;
311 	pll->hw.init = &init;
312 	pll->data = data;
313 
314 	init.name = data->name;
315 	init.flags = (data->flags & PLL_AO) ? CLK_IS_CRITICAL : 0;
316 	init.ops = pll_ops;
317 	if (data->parent_name)
318 		init.parent_names = &data->parent_name;
319 	else
320 		init.parent_names = &parent_name;
321 	init.num_parents = 1;
322 
323 	ret = clk_hw_register(NULL, &pll->hw);
324 
325 	if (ret)
326 		return ERR_PTR(ret);
327 
328 	return &pll->hw;
329 }
330 
331 struct clk_hw *mtk_clk_register_pll(const struct mtk_pll_data *data,
332 				    void __iomem *base)
333 {
334 	struct mtk_clk_pll *pll;
335 	struct clk_hw *hw;
336 
337 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
338 	if (!pll)
339 		return ERR_PTR(-ENOMEM);
340 
341 	hw = mtk_clk_register_pll_ops(pll, data, base, &mtk_pll_ops);
342 	if (IS_ERR(hw))
343 		kfree(pll);
344 
345 	return hw;
346 }
347 
348 void mtk_clk_unregister_pll(struct clk_hw *hw)
349 {
350 	struct mtk_clk_pll *pll;
351 
352 	if (!hw)
353 		return;
354 
355 	pll = to_mtk_clk_pll(hw);
356 
357 	clk_hw_unregister(hw);
358 	kfree(pll);
359 }
360 
361 int mtk_clk_register_plls(struct device_node *node,
362 			  const struct mtk_pll_data *plls, int num_plls,
363 			  struct clk_hw_onecell_data *clk_data)
364 {
365 	void __iomem *base;
366 	int i;
367 	struct clk_hw *hw;
368 
369 	base = of_iomap(node, 0);
370 	if (!base) {
371 		pr_err("%s(): ioremap failed\n", __func__);
372 		return -EINVAL;
373 	}
374 
375 	for (i = 0; i < num_plls; i++) {
376 		const struct mtk_pll_data *pll = &plls[i];
377 
378 		if (!IS_ERR_OR_NULL(clk_data->hws[pll->id])) {
379 			pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
380 				node, pll->id);
381 			continue;
382 		}
383 
384 		hw = mtk_clk_register_pll(pll, base);
385 
386 		if (IS_ERR(hw)) {
387 			pr_err("Failed to register clk %s: %pe\n", pll->name,
388 			       hw);
389 			goto err;
390 		}
391 
392 		clk_data->hws[pll->id] = hw;
393 	}
394 
395 	return 0;
396 
397 err:
398 	while (--i >= 0) {
399 		const struct mtk_pll_data *pll = &plls[i];
400 
401 		mtk_clk_unregister_pll(clk_data->hws[pll->id]);
402 		clk_data->hws[pll->id] = ERR_PTR(-ENOENT);
403 	}
404 
405 	iounmap(base);
406 
407 	return PTR_ERR(hw);
408 }
409 EXPORT_SYMBOL_GPL(mtk_clk_register_plls);
410 
411 __iomem void *mtk_clk_pll_get_base(struct clk_hw *hw,
412 				   const struct mtk_pll_data *data)
413 {
414 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
415 
416 	return pll->base_addr - data->reg;
417 }
418 
419 void mtk_clk_unregister_plls(const struct mtk_pll_data *plls, int num_plls,
420 			     struct clk_hw_onecell_data *clk_data)
421 {
422 	__iomem void *base = NULL;
423 	int i;
424 
425 	if (!clk_data)
426 		return;
427 
428 	for (i = num_plls; i > 0; i--) {
429 		const struct mtk_pll_data *pll = &plls[i - 1];
430 
431 		if (IS_ERR_OR_NULL(clk_data->hws[pll->id]))
432 			continue;
433 
434 		/*
435 		 * This is quite ugly but unfortunately the clks don't have
436 		 * any device tied to them, so there's no place to store the
437 		 * pointer to the I/O region base address. We have to fetch
438 		 * it from one of the registered clks.
439 		 */
440 		base = mtk_clk_pll_get_base(clk_data->hws[pll->id], pll);
441 
442 		mtk_clk_unregister_pll(clk_data->hws[pll->id]);
443 		clk_data->hws[pll->id] = ERR_PTR(-ENOENT);
444 	}
445 
446 	iounmap(base);
447 }
448 EXPORT_SYMBOL_GPL(mtk_clk_unregister_plls);
449 
450 MODULE_LICENSE("GPL");
451