xref: /linux/drivers/clk/imx/clk-fracn-gppll.c (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2021 NXP
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/clk-provider.h>
8 #include <linux/err.h>
9 #include <linux/export.h>
10 #include <linux/io.h>
11 #include <linux/iopoll.h>
12 #include <linux/slab.h>
13 #include <asm/div64.h>
14 
15 #include "clk.h"
16 
17 #define PLL_CTRL		0x0
18 #define HW_CTRL_SEL		BIT(16)
19 #define CLKMUX_BYPASS		BIT(2)
20 #define CLKMUX_EN		BIT(1)
21 #define POWERUP_MASK		BIT(0)
22 
23 #define PLL_ANA_PRG		0x10
24 #define PLL_SPREAD_SPECTRUM	0x30
25 
26 #define PLL_NUMERATOR		0x40
27 #define PLL_MFN_MASK		GENMASK(31, 2)
28 
29 #define PLL_DENOMINATOR		0x50
30 #define PLL_MFD_MASK		GENMASK(29, 0)
31 
32 #define PLL_DIV			0x60
33 #define PLL_MFI_MASK		GENMASK(24, 16)
34 #define PLL_RDIV_MASK		GENMASK(15, 13)
35 #define PLL_ODIV_MASK		GENMASK(7, 0)
36 
37 #define PLL_DFS_CTRL(x)		(0x70 + (x) * 0x10)
38 
39 #define PLL_STATUS		0xF0
40 #define LOCK_STATUS		BIT(0)
41 
42 #define DFS_STATUS		0xF4
43 
44 #define LOCK_TIMEOUT_US		200
45 
46 #define PLL_FRACN_GP(_rate, _mfi, _mfn, _mfd, _rdiv, _odiv)	\
47 	{							\
48 		.rate	=	(_rate),			\
49 		.mfi	=	(_mfi),				\
50 		.mfn	=	(_mfn),				\
51 		.mfd	=	(_mfd),				\
52 		.rdiv	=	(_rdiv),			\
53 		.odiv	=	(_odiv),			\
54 	}
55 
56 #define PLL_FRACN_GP_INTEGER(_rate, _mfi, _rdiv, _odiv)		\
57 	{							\
58 		.rate	=	(_rate),			\
59 		.mfi	=	(_mfi),				\
60 		.mfn	=	0,				\
61 		.mfd	=	0,				\
62 		.rdiv	=	(_rdiv),			\
63 		.odiv	=	(_odiv),			\
64 	}
65 
66 struct clk_fracn_gppll {
67 	struct clk_hw			hw;
68 	void __iomem			*base;
69 	const struct imx_fracn_gppll_rate_table *rate_table;
70 	int rate_count;
71 	u32 flags;
72 };
73 
74 /*
75  * Fvco = (Fref / rdiv) * (MFI + MFN / MFD)
76  * Fout = Fvco / odiv
77  * The (Fref / rdiv) should be in range 20MHz to 40MHz
78  * The Fvco should be in range 2.5Ghz to 5Ghz
79  */
80 static const struct imx_fracn_gppll_rate_table fracn_tbl[] = {
81 	PLL_FRACN_GP(650000000U, 162, 50, 100, 0, 6),
82 	PLL_FRACN_GP(594000000U, 198, 0, 1, 0, 8),
83 	PLL_FRACN_GP(560000000U, 140, 0, 1, 0, 6),
84 	PLL_FRACN_GP(519750000U, 173, 25, 100, 1, 8),
85 	PLL_FRACN_GP(498000000U, 166, 0, 1, 0, 8),
86 	PLL_FRACN_GP(484000000U, 121, 0, 1, 0, 6),
87 	PLL_FRACN_GP(445333333U, 167, 0, 1, 0, 9),
88 	PLL_FRACN_GP(400000000U, 200, 0, 1, 0, 12),
89 	PLL_FRACN_GP(393216000U, 163, 84, 100, 0, 10),
90 	PLL_FRACN_GP(300000000U, 150, 0, 1, 0, 12)
91 };
92 
93 struct imx_fracn_gppll_clk imx_fracn_gppll = {
94 	.rate_table = fracn_tbl,
95 	.rate_count = ARRAY_SIZE(fracn_tbl),
96 };
97 EXPORT_SYMBOL_GPL(imx_fracn_gppll);
98 
99 /*
100  * Fvco = (Fref / rdiv) * MFI
101  * Fout = Fvco / odiv
102  * The (Fref / rdiv) should be in range 20MHz to 40MHz
103  * The Fvco should be in range 2.5Ghz to 5Ghz
104  */
105 static const struct imx_fracn_gppll_rate_table int_tbl[] = {
106 	PLL_FRACN_GP_INTEGER(1700000000U, 141, 1, 2),
107 	PLL_FRACN_GP_INTEGER(1400000000U, 175, 1, 3),
108 	PLL_FRACN_GP_INTEGER(900000000U, 150, 1, 4),
109 };
110 
111 struct imx_fracn_gppll_clk imx_fracn_gppll_integer = {
112 	.rate_table = int_tbl,
113 	.rate_count = ARRAY_SIZE(int_tbl),
114 };
115 EXPORT_SYMBOL_GPL(imx_fracn_gppll_integer);
116 
117 static inline struct clk_fracn_gppll *to_clk_fracn_gppll(struct clk_hw *hw)
118 {
119 	return container_of(hw, struct clk_fracn_gppll, hw);
120 }
121 
122 static const struct imx_fracn_gppll_rate_table *
123 imx_get_pll_settings(struct clk_fracn_gppll *pll, unsigned long rate)
124 {
125 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
126 	int i;
127 
128 	for (i = 0; i < pll->rate_count; i++)
129 		if (rate == rate_table[i].rate)
130 			return &rate_table[i];
131 
132 	return NULL;
133 }
134 
135 static long clk_fracn_gppll_round_rate(struct clk_hw *hw, unsigned long rate,
136 				       unsigned long *prate)
137 {
138 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
139 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
140 	int i;
141 
142 	/* Assuming rate_table is in descending order */
143 	for (i = 0; i < pll->rate_count; i++)
144 		if (rate >= rate_table[i].rate)
145 			return rate_table[i].rate;
146 
147 	/* return minimum supported value */
148 	return rate_table[pll->rate_count - 1].rate;
149 }
150 
151 static unsigned long clk_fracn_gppll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
152 {
153 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
154 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
155 	u32 pll_numerator, pll_denominator, pll_div;
156 	u32 mfi, mfn, mfd, rdiv, odiv;
157 	u64 fvco = parent_rate;
158 	long rate = 0;
159 	int i;
160 
161 	pll_numerator = readl_relaxed(pll->base + PLL_NUMERATOR);
162 	mfn = FIELD_GET(PLL_MFN_MASK, pll_numerator);
163 
164 	pll_denominator = readl_relaxed(pll->base + PLL_DENOMINATOR);
165 	mfd = FIELD_GET(PLL_MFD_MASK, pll_denominator);
166 
167 	pll_div = readl_relaxed(pll->base + PLL_DIV);
168 	mfi = FIELD_GET(PLL_MFI_MASK, pll_div);
169 
170 	rdiv = FIELD_GET(PLL_RDIV_MASK, pll_div);
171 	odiv = FIELD_GET(PLL_ODIV_MASK, pll_div);
172 
173 	/*
174 	 * Sometimes, the recalculated rate has deviation due to
175 	 * the frac part. So find the accurate pll rate from the table
176 	 * first, if no match rate in the table, use the rate calculated
177 	 * from the equation below.
178 	 */
179 	for (i = 0; i < pll->rate_count; i++) {
180 		if (rate_table[i].mfn == mfn && rate_table[i].mfi == mfi &&
181 		    rate_table[i].mfd == mfd && rate_table[i].rdiv == rdiv &&
182 		    rate_table[i].odiv == odiv)
183 			rate = rate_table[i].rate;
184 	}
185 
186 	if (rate)
187 		return (unsigned long)rate;
188 
189 	if (!rdiv)
190 		rdiv = rdiv + 1;
191 
192 	switch (odiv) {
193 	case 0:
194 		odiv = 2;
195 		break;
196 	case 1:
197 		odiv = 3;
198 		break;
199 	default:
200 		break;
201 	}
202 
203 	if (pll->flags & CLK_FRACN_GPPLL_INTEGER) {
204 		/* Fvco = (Fref / rdiv) * MFI */
205 		fvco = fvco * mfi;
206 		do_div(fvco, rdiv * odiv);
207 	} else {
208 		/* Fvco = (Fref / rdiv) * (MFI + MFN / MFD) */
209 		fvco = fvco * mfi * mfd + fvco * mfn;
210 		do_div(fvco, mfd * rdiv * odiv);
211 	}
212 
213 	return (unsigned long)fvco;
214 }
215 
216 static int clk_fracn_gppll_wait_lock(struct clk_fracn_gppll *pll)
217 {
218 	u32 val;
219 
220 	return readl_poll_timeout(pll->base + PLL_STATUS, val,
221 				  val & LOCK_STATUS, 0, LOCK_TIMEOUT_US);
222 }
223 
224 static int clk_fracn_gppll_set_rate(struct clk_hw *hw, unsigned long drate,
225 				    unsigned long prate)
226 {
227 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
228 	const struct imx_fracn_gppll_rate_table *rate;
229 	u32 tmp, pll_div, ana_mfn;
230 	int ret;
231 
232 	rate = imx_get_pll_settings(pll, drate);
233 
234 	/* Hardware control select disable. PLL is control by register */
235 	tmp = readl_relaxed(pll->base + PLL_CTRL);
236 	tmp &= ~HW_CTRL_SEL;
237 	writel_relaxed(tmp, pll->base + PLL_CTRL);
238 
239 	/* Disable output */
240 	tmp = readl_relaxed(pll->base + PLL_CTRL);
241 	tmp &= ~CLKMUX_EN;
242 	writel_relaxed(tmp, pll->base + PLL_CTRL);
243 
244 	/* Power Down */
245 	tmp &= ~POWERUP_MASK;
246 	writel_relaxed(tmp, pll->base + PLL_CTRL);
247 
248 	/* Disable BYPASS */
249 	tmp &= ~CLKMUX_BYPASS;
250 	writel_relaxed(tmp, pll->base + PLL_CTRL);
251 
252 	pll_div = FIELD_PREP(PLL_RDIV_MASK, rate->rdiv) | rate->odiv |
253 		FIELD_PREP(PLL_MFI_MASK, rate->mfi);
254 	writel_relaxed(pll_div, pll->base + PLL_DIV);
255 	if (pll->flags & CLK_FRACN_GPPLL_FRACN) {
256 		writel_relaxed(rate->mfd, pll->base + PLL_DENOMINATOR);
257 		writel_relaxed(FIELD_PREP(PLL_MFN_MASK, rate->mfn), pll->base + PLL_NUMERATOR);
258 	}
259 
260 	/* Wait for 5us according to fracn mode pll doc */
261 	udelay(5);
262 
263 	/* Enable Powerup */
264 	tmp |= POWERUP_MASK;
265 	writel_relaxed(tmp, pll->base + PLL_CTRL);
266 
267 	/* Wait Lock */
268 	ret = clk_fracn_gppll_wait_lock(pll);
269 	if (ret)
270 		return ret;
271 
272 	/* Enable output */
273 	tmp |= CLKMUX_EN;
274 	writel_relaxed(tmp, pll->base + PLL_CTRL);
275 
276 	ana_mfn = readl_relaxed(pll->base + PLL_STATUS);
277 	ana_mfn = FIELD_GET(PLL_MFN_MASK, ana_mfn);
278 
279 	WARN(ana_mfn != rate->mfn, "ana_mfn != rate->mfn\n");
280 
281 	return 0;
282 }
283 
284 static int clk_fracn_gppll_prepare(struct clk_hw *hw)
285 {
286 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
287 	u32 val;
288 	int ret;
289 
290 	val = readl_relaxed(pll->base + PLL_CTRL);
291 	if (val & POWERUP_MASK)
292 		return 0;
293 
294 	val |= CLKMUX_BYPASS;
295 	writel_relaxed(val, pll->base + PLL_CTRL);
296 
297 	val |= POWERUP_MASK;
298 	writel_relaxed(val, pll->base + PLL_CTRL);
299 
300 	val |= CLKMUX_EN;
301 	writel_relaxed(val, pll->base + PLL_CTRL);
302 
303 	ret = clk_fracn_gppll_wait_lock(pll);
304 	if (ret)
305 		return ret;
306 
307 	val &= ~CLKMUX_BYPASS;
308 	writel_relaxed(val, pll->base + PLL_CTRL);
309 
310 	return 0;
311 }
312 
313 static int clk_fracn_gppll_is_prepared(struct clk_hw *hw)
314 {
315 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
316 	u32 val;
317 
318 	val = readl_relaxed(pll->base + PLL_CTRL);
319 
320 	return (val & POWERUP_MASK) ? 1 : 0;
321 }
322 
323 static void clk_fracn_gppll_unprepare(struct clk_hw *hw)
324 {
325 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
326 	u32 val;
327 
328 	val = readl_relaxed(pll->base + PLL_CTRL);
329 	val &= ~POWERUP_MASK;
330 	writel_relaxed(val, pll->base + PLL_CTRL);
331 }
332 
333 static const struct clk_ops clk_fracn_gppll_ops = {
334 	.prepare	= clk_fracn_gppll_prepare,
335 	.unprepare	= clk_fracn_gppll_unprepare,
336 	.is_prepared	= clk_fracn_gppll_is_prepared,
337 	.recalc_rate	= clk_fracn_gppll_recalc_rate,
338 	.round_rate	= clk_fracn_gppll_round_rate,
339 	.set_rate	= clk_fracn_gppll_set_rate,
340 };
341 
342 static struct clk_hw *_imx_clk_fracn_gppll(const char *name, const char *parent_name,
343 					   void __iomem *base,
344 					   const struct imx_fracn_gppll_clk *pll_clk,
345 					   u32 pll_flags)
346 {
347 	struct clk_fracn_gppll *pll;
348 	struct clk_hw *hw;
349 	struct clk_init_data init;
350 	int ret;
351 
352 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
353 	if (!pll)
354 		return ERR_PTR(-ENOMEM);
355 
356 	init.name = name;
357 	init.flags = pll_clk->flags;
358 	init.parent_names = &parent_name;
359 	init.num_parents = 1;
360 	init.ops = &clk_fracn_gppll_ops;
361 
362 	pll->base = base;
363 	pll->hw.init = &init;
364 	pll->rate_table = pll_clk->rate_table;
365 	pll->rate_count = pll_clk->rate_count;
366 	pll->flags = pll_flags;
367 
368 	hw = &pll->hw;
369 
370 	ret = clk_hw_register(NULL, hw);
371 	if (ret) {
372 		pr_err("%s: failed to register pll %s %d\n", __func__, name, ret);
373 		kfree(pll);
374 		return ERR_PTR(ret);
375 	}
376 
377 	return hw;
378 }
379 
380 struct clk_hw *imx_clk_fracn_gppll(const char *name, const char *parent_name, void __iomem *base,
381 				   const struct imx_fracn_gppll_clk *pll_clk)
382 {
383 	return _imx_clk_fracn_gppll(name, parent_name, base, pll_clk, CLK_FRACN_GPPLL_FRACN);
384 }
385 EXPORT_SYMBOL_GPL(imx_clk_fracn_gppll);
386 
387 struct clk_hw *imx_clk_fracn_gppll_integer(const char *name, const char *parent_name,
388 					   void __iomem *base,
389 					   const struct imx_fracn_gppll_clk *pll_clk)
390 {
391 	return _imx_clk_fracn_gppll(name, parent_name, base, pll_clk, CLK_FRACN_GPPLL_INTEGER);
392 }
393 EXPORT_SYMBOL_GPL(imx_clk_fracn_gppll_integer);
394