xref: /openbmc/linux/drivers/clk/imx/clk-pll14xx.c (revision 8440bb9b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2017-2018 NXP.
4  */
5 
6 #include <linux/bitops.h>
7 #include <linux/clk-provider.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/iopoll.h>
11 #include <linux/slab.h>
12 #include <linux/jiffies.h>
13 
14 #include "clk.h"
15 
16 #define GNRL_CTL	0x0
17 #define DIV_CTL		0x4
18 #define LOCK_STATUS	BIT(31)
19 #define LOCK_SEL_MASK	BIT(29)
20 #define CLKE_MASK	BIT(11)
21 #define RST_MASK	BIT(9)
22 #define BYPASS_MASK	BIT(4)
23 #define MDIV_SHIFT	12
24 #define MDIV_MASK	GENMASK(21, 12)
25 #define PDIV_SHIFT	4
26 #define PDIV_MASK	GENMASK(9, 4)
27 #define SDIV_SHIFT	0
28 #define SDIV_MASK	GENMASK(2, 0)
29 #define KDIV_SHIFT	0
30 #define KDIV_MASK	GENMASK(15, 0)
31 
32 #define LOCK_TIMEOUT_US		10000
33 
34 struct clk_pll14xx {
35 	struct clk_hw			hw;
36 	void __iomem			*base;
37 	enum imx_pll14xx_type		type;
38 	const struct imx_pll14xx_rate_table *rate_table;
39 	int rate_count;
40 };
41 
42 #define to_clk_pll14xx(_hw) container_of(_hw, struct clk_pll14xx, hw)
43 
44 static const struct imx_pll14xx_rate_table *imx_get_pll_settings(
45 		struct clk_pll14xx *pll, unsigned long rate)
46 {
47 	const struct imx_pll14xx_rate_table *rate_table = pll->rate_table;
48 	int i;
49 
50 	for (i = 0; i < pll->rate_count; i++)
51 		if (rate == rate_table[i].rate)
52 			return &rate_table[i];
53 
54 	return NULL;
55 }
56 
57 static long clk_pll14xx_round_rate(struct clk_hw *hw, unsigned long rate,
58 			unsigned long *prate)
59 {
60 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
61 	const struct imx_pll14xx_rate_table *rate_table = pll->rate_table;
62 	int i;
63 
64 	/* Assumming rate_table is in descending order */
65 	for (i = 0; i < pll->rate_count; i++)
66 		if (rate >= rate_table[i].rate)
67 			return rate_table[i].rate;
68 
69 	/* return minimum supported value */
70 	return rate_table[i - 1].rate;
71 }
72 
73 static unsigned long clk_pll1416x_recalc_rate(struct clk_hw *hw,
74 						  unsigned long parent_rate)
75 {
76 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
77 	u32 mdiv, pdiv, sdiv, pll_gnrl, pll_div;
78 	u64 fvco = parent_rate;
79 
80 	pll_gnrl = readl_relaxed(pll->base);
81 	pll_div = readl_relaxed(pll->base + 4);
82 	mdiv = (pll_div & MDIV_MASK) >> MDIV_SHIFT;
83 	pdiv = (pll_div & PDIV_MASK) >> PDIV_SHIFT;
84 	sdiv = (pll_div & SDIV_MASK) >> SDIV_SHIFT;
85 
86 	fvco *= mdiv;
87 	do_div(fvco, pdiv << sdiv);
88 
89 	return fvco;
90 }
91 
92 static unsigned long clk_pll1443x_recalc_rate(struct clk_hw *hw,
93 						  unsigned long parent_rate)
94 {
95 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
96 	u32 mdiv, pdiv, sdiv, pll_gnrl, pll_div_ctl0, pll_div_ctl1;
97 	short int kdiv;
98 	u64 fvco = parent_rate;
99 
100 	pll_gnrl = readl_relaxed(pll->base);
101 	pll_div_ctl0 = readl_relaxed(pll->base + 4);
102 	pll_div_ctl1 = readl_relaxed(pll->base + 8);
103 	mdiv = (pll_div_ctl0 & MDIV_MASK) >> MDIV_SHIFT;
104 	pdiv = (pll_div_ctl0 & PDIV_MASK) >> PDIV_SHIFT;
105 	sdiv = (pll_div_ctl0 & SDIV_MASK) >> SDIV_SHIFT;
106 	kdiv = pll_div_ctl1 & KDIV_MASK;
107 
108 	/* fvco = (m * 65536 + k) * Fin / (p * 65536) */
109 	fvco *= (mdiv * 65536 + kdiv);
110 	pdiv *= 65536;
111 
112 	do_div(fvco, pdiv << sdiv);
113 
114 	return fvco;
115 }
116 
117 static inline bool clk_pll1416x_mp_change(const struct imx_pll14xx_rate_table *rate,
118 					  u32 pll_div)
119 {
120 	u32 old_mdiv, old_pdiv;
121 
122 	old_mdiv = (pll_div >> MDIV_SHIFT) & MDIV_MASK;
123 	old_pdiv = (pll_div >> PDIV_SHIFT) & PDIV_MASK;
124 
125 	return rate->mdiv != old_mdiv || rate->pdiv != old_pdiv;
126 }
127 
128 static inline bool clk_pll1443x_mpk_change(const struct imx_pll14xx_rate_table *rate,
129 					  u32 pll_div_ctl0, u32 pll_div_ctl1)
130 {
131 	u32 old_mdiv, old_pdiv, old_kdiv;
132 
133 	old_mdiv = (pll_div_ctl0 >> MDIV_SHIFT) & MDIV_MASK;
134 	old_pdiv = (pll_div_ctl0 >> PDIV_SHIFT) & PDIV_MASK;
135 	old_kdiv = (pll_div_ctl1 >> KDIV_SHIFT) & KDIV_MASK;
136 
137 	return rate->mdiv != old_mdiv || rate->pdiv != old_pdiv ||
138 		rate->kdiv != old_kdiv;
139 }
140 
141 static inline bool clk_pll1443x_mp_change(const struct imx_pll14xx_rate_table *rate,
142 					  u32 pll_div_ctl0, u32 pll_div_ctl1)
143 {
144 	u32 old_mdiv, old_pdiv, old_kdiv;
145 
146 	old_mdiv = (pll_div_ctl0 >> MDIV_SHIFT) & MDIV_MASK;
147 	old_pdiv = (pll_div_ctl0 >> PDIV_SHIFT) & PDIV_MASK;
148 	old_kdiv = (pll_div_ctl1 >> KDIV_SHIFT) & KDIV_MASK;
149 
150 	return rate->mdiv != old_mdiv || rate->pdiv != old_pdiv ||
151 		rate->kdiv != old_kdiv;
152 }
153 
154 static int clk_pll14xx_wait_lock(struct clk_pll14xx *pll)
155 {
156 	u32 val;
157 
158 	return readl_poll_timeout(pll->base, val, val & LOCK_TIMEOUT_US, 0,
159 			LOCK_TIMEOUT_US);
160 }
161 
162 static int clk_pll1416x_set_rate(struct clk_hw *hw, unsigned long drate,
163 				 unsigned long prate)
164 {
165 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
166 	const struct imx_pll14xx_rate_table *rate;
167 	u32 tmp, div_val;
168 	int ret;
169 
170 	rate = imx_get_pll_settings(pll, drate);
171 	if (!rate) {
172 		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
173 		       drate, clk_hw_get_name(hw));
174 		return -EINVAL;
175 	}
176 
177 	tmp = readl_relaxed(pll->base + 4);
178 
179 	if (!clk_pll1416x_mp_change(rate, tmp)) {
180 		tmp &= ~(SDIV_MASK) << SDIV_SHIFT;
181 		tmp |= rate->sdiv << SDIV_SHIFT;
182 		writel_relaxed(tmp, pll->base + 4);
183 
184 		return 0;
185 	}
186 
187 	/* Bypass clock and set lock to pll output lock */
188 	tmp = readl_relaxed(pll->base);
189 	tmp |= LOCK_SEL_MASK;
190 	writel_relaxed(tmp, pll->base);
191 
192 	/* Enable RST */
193 	tmp &= ~RST_MASK;
194 	writel_relaxed(tmp, pll->base);
195 
196 	div_val = (rate->mdiv << MDIV_SHIFT) | (rate->pdiv << PDIV_SHIFT) |
197 		(rate->sdiv << SDIV_SHIFT);
198 	writel_relaxed(div_val, pll->base + 0x4);
199 
200 	/*
201 	 * According to SPEC, t3 - t2 need to be greater than
202 	 * 1us and 1/FREF, respectively.
203 	 * FREF is FIN / Prediv, the prediv is [1, 63], so choose
204 	 * 3us.
205 	 */
206 	udelay(3);
207 
208 	/* Disable RST */
209 	tmp |= RST_MASK;
210 	writel_relaxed(tmp, pll->base);
211 
212 	/* Wait Lock */
213 	ret = clk_pll14xx_wait_lock(pll);
214 	if (ret)
215 		return ret;
216 
217 	/* Bypass */
218 	tmp &= ~BYPASS_MASK;
219 	writel_relaxed(tmp, pll->base);
220 
221 	return 0;
222 }
223 
224 static int clk_pll1443x_set_rate(struct clk_hw *hw, unsigned long drate,
225 				 unsigned long prate)
226 {
227 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
228 	const struct imx_pll14xx_rate_table *rate;
229 	u32 tmp, div_val;
230 	int ret;
231 
232 	rate = imx_get_pll_settings(pll, drate);
233 	if (!rate) {
234 		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
235 			drate, clk_hw_get_name(hw));
236 		return -EINVAL;
237 	}
238 
239 	tmp = readl_relaxed(pll->base + 4);
240 	div_val = readl_relaxed(pll->base + 8);
241 
242 	if (!clk_pll1443x_mpk_change(rate, tmp, div_val)) {
243 		tmp &= ~(SDIV_MASK) << SDIV_SHIFT;
244 		tmp |= rate->sdiv << SDIV_SHIFT;
245 		writel_relaxed(tmp, pll->base + 4);
246 
247 		return 0;
248 	}
249 
250 	/* Enable RST */
251 	tmp = readl_relaxed(pll->base);
252 	tmp &= ~RST_MASK;
253 	writel_relaxed(tmp, pll->base);
254 
255 	div_val = (rate->mdiv << MDIV_SHIFT) | (rate->pdiv << PDIV_SHIFT) |
256 		(rate->sdiv << SDIV_SHIFT);
257 	writel_relaxed(div_val, pll->base + 0x4);
258 	writel_relaxed(rate->kdiv << KDIV_SHIFT, pll->base + 0x8);
259 
260 	/*
261 	 * According to SPEC, t3 - t2 need to be greater than
262 	 * 1us and 1/FREF, respectively.
263 	 * FREF is FIN / Prediv, the prediv is [1, 63], so choose
264 	 * 3us.
265 	 */
266 	udelay(3);
267 
268 	/* Disable RST */
269 	tmp |= RST_MASK;
270 	writel_relaxed(tmp, pll->base);
271 
272 	/* Wait Lock*/
273 	ret = clk_pll14xx_wait_lock(pll);
274 	if (ret)
275 		return ret;
276 
277 	/* Bypass */
278 	tmp &= ~BYPASS_MASK;
279 	writel_relaxed(tmp, pll->base);
280 
281 	return 0;
282 }
283 
284 static int clk_pll14xx_prepare(struct clk_hw *hw)
285 {
286 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
287 	u32 val;
288 
289 	/*
290 	 * RESETB = 1 from 0, PLL starts its normal
291 	 * operation after lock time
292 	 */
293 	val = readl_relaxed(pll->base + GNRL_CTL);
294 	val |= RST_MASK;
295 	writel_relaxed(val, pll->base + GNRL_CTL);
296 
297 	return clk_pll14xx_wait_lock(pll);
298 }
299 
300 static int clk_pll14xx_is_prepared(struct clk_hw *hw)
301 {
302 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
303 	u32 val;
304 
305 	val = readl_relaxed(pll->base + GNRL_CTL);
306 
307 	return (val & RST_MASK) ? 1 : 0;
308 }
309 
310 static void clk_pll14xx_unprepare(struct clk_hw *hw)
311 {
312 	struct clk_pll14xx *pll = to_clk_pll14xx(hw);
313 	u32 val;
314 
315 	/*
316 	 * Set RST to 0, power down mode is enabled and
317 	 * every digital block is reset
318 	 */
319 	val = readl_relaxed(pll->base + GNRL_CTL);
320 	val &= ~RST_MASK;
321 	writel_relaxed(val, pll->base + GNRL_CTL);
322 }
323 
324 static const struct clk_ops clk_pll1416x_ops = {
325 	.prepare	= clk_pll14xx_prepare,
326 	.unprepare	= clk_pll14xx_unprepare,
327 	.is_prepared	= clk_pll14xx_is_prepared,
328 	.recalc_rate	= clk_pll1416x_recalc_rate,
329 	.round_rate	= clk_pll14xx_round_rate,
330 	.set_rate	= clk_pll1416x_set_rate,
331 };
332 
333 static const struct clk_ops clk_pll1416x_min_ops = {
334 	.recalc_rate	= clk_pll1416x_recalc_rate,
335 };
336 
337 static const struct clk_ops clk_pll1443x_ops = {
338 	.prepare	= clk_pll14xx_prepare,
339 	.unprepare	= clk_pll14xx_unprepare,
340 	.is_prepared	= clk_pll14xx_is_prepared,
341 	.recalc_rate	= clk_pll1443x_recalc_rate,
342 	.round_rate	= clk_pll14xx_round_rate,
343 	.set_rate	= clk_pll1443x_set_rate,
344 };
345 
346 struct clk *imx_clk_pll14xx(const char *name, const char *parent_name,
347 			    void __iomem *base,
348 			    const struct imx_pll14xx_clk *pll_clk)
349 {
350 	struct clk_pll14xx *pll;
351 	struct clk *clk;
352 	struct clk_init_data init;
353 
354 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
355 	if (!pll)
356 		return ERR_PTR(-ENOMEM);
357 
358 	init.name = name;
359 	init.flags = pll_clk->flags;
360 	init.parent_names = &parent_name;
361 	init.num_parents = 1;
362 
363 	switch (pll_clk->type) {
364 	case PLL_1416X:
365 		if (!pll->rate_table)
366 			init.ops = &clk_pll1416x_min_ops;
367 		else
368 			init.ops = &clk_pll1416x_ops;
369 		break;
370 	case PLL_1443X:
371 		init.ops = &clk_pll1443x_ops;
372 		break;
373 	default:
374 		pr_err("%s: Unknown pll type for pll clk %s\n",
375 		       __func__, name);
376 	};
377 
378 	pll->base = base;
379 	pll->hw.init = &init;
380 	pll->type = pll_clk->type;
381 	pll->rate_table = pll_clk->rate_table;
382 	pll->rate_count = pll_clk->rate_count;
383 
384 	clk = clk_register(NULL, &pll->hw);
385 	if (IS_ERR(clk)) {
386 		pr_err("%s: failed to register pll %s %lu\n",
387 			__func__, name, PTR_ERR(clk));
388 		kfree(pll);
389 	}
390 
391 	return clk;
392 }
393