xref: /linux/drivers/clk/imx/clk-fracn-gppll.c (revision 746680ec6696585e30db3e18c93a63df9cbec39c)
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(1039500000U, 173, 25, 100, 1, 4),
82 	PLL_FRACN_GP(650000000U, 162, 50, 100, 0, 6),
83 	PLL_FRACN_GP(594000000U, 198, 0, 1, 0, 8),
84 	PLL_FRACN_GP(560000000U, 140, 0, 1, 0, 6),
85 	PLL_FRACN_GP(519750000U, 173, 25, 100, 1, 8),
86 	PLL_FRACN_GP(498000000U, 166, 0, 1, 0, 8),
87 	PLL_FRACN_GP(484000000U, 121, 0, 1, 0, 6),
88 	PLL_FRACN_GP(445333333U, 167, 0, 1, 0, 9),
89 	PLL_FRACN_GP(400000000U, 200, 0, 1, 0, 12),
90 	PLL_FRACN_GP(393216000U, 163, 84, 100, 0, 10),
91 	PLL_FRACN_GP(300000000U, 150, 0, 1, 0, 12)
92 };
93 
94 struct imx_fracn_gppll_clk imx_fracn_gppll = {
95 	.rate_table = fracn_tbl,
96 	.rate_count = ARRAY_SIZE(fracn_tbl),
97 };
98 EXPORT_SYMBOL_GPL(imx_fracn_gppll);
99 
100 /*
101  * Fvco = (Fref / rdiv) * MFI
102  * Fout = Fvco / odiv
103  * The (Fref / rdiv) should be in range 20MHz to 40MHz
104  * The Fvco should be in range 2.5Ghz to 5Ghz
105  */
106 static const struct imx_fracn_gppll_rate_table int_tbl[] = {
107 	PLL_FRACN_GP_INTEGER(1700000000U, 141, 1, 2),
108 	PLL_FRACN_GP_INTEGER(1400000000U, 175, 1, 3),
109 	PLL_FRACN_GP_INTEGER(900000000U, 150, 1, 4),
110 	PLL_FRACN_GP_INTEGER(800000000U, 200, 1, 6),
111 };
112 
113 struct imx_fracn_gppll_clk imx_fracn_gppll_integer = {
114 	.rate_table = int_tbl,
115 	.rate_count = ARRAY_SIZE(int_tbl),
116 };
117 EXPORT_SYMBOL_GPL(imx_fracn_gppll_integer);
118 
119 static inline struct clk_fracn_gppll *to_clk_fracn_gppll(struct clk_hw *hw)
120 {
121 	return container_of(hw, struct clk_fracn_gppll, hw);
122 }
123 
124 static const struct imx_fracn_gppll_rate_table *
125 imx_get_pll_settings(struct clk_fracn_gppll *pll, unsigned long rate)
126 {
127 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
128 	int i;
129 
130 	for (i = 0; i < pll->rate_count; i++)
131 		if (rate == rate_table[i].rate)
132 			return &rate_table[i];
133 
134 	return NULL;
135 }
136 
137 static int clk_fracn_gppll_determine_rate(struct clk_hw *hw,
138 					  struct clk_rate_request *req)
139 {
140 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
141 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
142 	int i;
143 
144 	/* Assuming rate_table is in descending order */
145 	for (i = 0; i < pll->rate_count; i++)
146 		if (req->rate >= rate_table[i].rate) {
147 			req->rate = rate_table[i].rate;
148 
149 			return 0;
150 		}
151 
152 	/* return minimum supported value */
153 	req->rate = rate_table[pll->rate_count - 1].rate;
154 
155 	return 0;
156 }
157 
158 static unsigned long clk_fracn_gppll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
159 {
160 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
161 	const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table;
162 	u32 pll_numerator, pll_denominator, pll_div;
163 	u32 mfi, mfn, mfd, rdiv, odiv;
164 	u64 fvco = parent_rate;
165 	long rate = 0;
166 	int i;
167 
168 	pll_numerator = readl_relaxed(pll->base + PLL_NUMERATOR);
169 	mfn = FIELD_GET(PLL_MFN_MASK, pll_numerator);
170 
171 	pll_denominator = readl_relaxed(pll->base + PLL_DENOMINATOR);
172 	mfd = FIELD_GET(PLL_MFD_MASK, pll_denominator);
173 
174 	pll_div = readl_relaxed(pll->base + PLL_DIV);
175 	mfi = FIELD_GET(PLL_MFI_MASK, pll_div);
176 
177 	rdiv = FIELD_GET(PLL_RDIV_MASK, pll_div);
178 	odiv = FIELD_GET(PLL_ODIV_MASK, pll_div);
179 
180 	/*
181 	 * Sometimes, the recalculated rate has deviation due to
182 	 * the frac part. So find the accurate pll rate from the table
183 	 * first, if no match rate in the table, use the rate calculated
184 	 * from the equation below.
185 	 */
186 	for (i = 0; i < pll->rate_count; i++) {
187 		if (rate_table[i].mfn == mfn && rate_table[i].mfi == mfi &&
188 		    rate_table[i].mfd == mfd && rate_table[i].rdiv == rdiv &&
189 		    rate_table[i].odiv == odiv)
190 			rate = rate_table[i].rate;
191 	}
192 
193 	if (rate)
194 		return (unsigned long)rate;
195 
196 	if (!rdiv)
197 		rdiv = rdiv + 1;
198 
199 	switch (odiv) {
200 	case 0:
201 		odiv = 2;
202 		break;
203 	case 1:
204 		odiv = 3;
205 		break;
206 	default:
207 		break;
208 	}
209 
210 	if (pll->flags & CLK_FRACN_GPPLL_INTEGER) {
211 		/* Fvco = (Fref / rdiv) * MFI */
212 		fvco = fvco * mfi;
213 		do_div(fvco, rdiv * odiv);
214 	} else {
215 		/* Fvco = (Fref / rdiv) * (MFI + MFN / MFD) */
216 		fvco = fvco * mfi * mfd + fvco * mfn;
217 		do_div(fvco, mfd * rdiv * odiv);
218 	}
219 
220 	return (unsigned long)fvco;
221 }
222 
223 static int clk_fracn_gppll_wait_lock(struct clk_fracn_gppll *pll)
224 {
225 	u32 val;
226 
227 	return readl_poll_timeout(pll->base + PLL_STATUS, val,
228 				  val & LOCK_STATUS, 0, LOCK_TIMEOUT_US);
229 }
230 
231 static int clk_fracn_gppll_set_rate(struct clk_hw *hw, unsigned long drate,
232 				    unsigned long prate)
233 {
234 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
235 	const struct imx_fracn_gppll_rate_table *rate;
236 	u32 tmp, pll_div, ana_mfn;
237 	int ret;
238 
239 	rate = imx_get_pll_settings(pll, drate);
240 
241 	/* Hardware control select disable. PLL is control by register */
242 	tmp = readl_relaxed(pll->base + PLL_CTRL);
243 	tmp &= ~HW_CTRL_SEL;
244 	writel_relaxed(tmp, pll->base + PLL_CTRL);
245 
246 	/* Disable output */
247 	tmp = readl_relaxed(pll->base + PLL_CTRL);
248 	tmp &= ~CLKMUX_EN;
249 	writel_relaxed(tmp, pll->base + PLL_CTRL);
250 
251 	/* Power Down */
252 	tmp &= ~POWERUP_MASK;
253 	writel_relaxed(tmp, pll->base + PLL_CTRL);
254 
255 	/* Disable BYPASS */
256 	tmp &= ~CLKMUX_BYPASS;
257 	writel_relaxed(tmp, pll->base + PLL_CTRL);
258 
259 	pll_div = FIELD_PREP(PLL_RDIV_MASK, rate->rdiv) | rate->odiv |
260 		FIELD_PREP(PLL_MFI_MASK, rate->mfi);
261 	writel_relaxed(pll_div, pll->base + PLL_DIV);
262 	readl(pll->base + PLL_DIV);
263 	if (pll->flags & CLK_FRACN_GPPLL_FRACN) {
264 		writel_relaxed(rate->mfd, pll->base + PLL_DENOMINATOR);
265 		writel_relaxed(FIELD_PREP(PLL_MFN_MASK, rate->mfn), pll->base + PLL_NUMERATOR);
266 		readl(pll->base + PLL_NUMERATOR);
267 	}
268 
269 	/* Wait for 5us according to fracn mode pll doc */
270 	udelay(5);
271 
272 	/* Enable Powerup */
273 	tmp |= POWERUP_MASK;
274 	writel_relaxed(tmp, pll->base + PLL_CTRL);
275 	readl(pll->base + PLL_CTRL);
276 
277 	/* Wait Lock */
278 	ret = clk_fracn_gppll_wait_lock(pll);
279 	if (ret)
280 		return ret;
281 
282 	/* Enable output */
283 	tmp |= CLKMUX_EN;
284 	writel_relaxed(tmp, pll->base + PLL_CTRL);
285 
286 	ana_mfn = readl_relaxed(pll->base + PLL_STATUS);
287 	ana_mfn = FIELD_GET(PLL_MFN_MASK, ana_mfn);
288 
289 	WARN(ana_mfn != rate->mfn, "ana_mfn != rate->mfn\n");
290 
291 	return 0;
292 }
293 
294 static int clk_fracn_gppll_prepare(struct clk_hw *hw)
295 {
296 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
297 	u32 val;
298 	int ret;
299 
300 	val = readl_relaxed(pll->base + PLL_CTRL);
301 	if (val & POWERUP_MASK)
302 		return 0;
303 
304 	if (pll->flags & CLK_FRACN_GPPLL_FRACN)
305 		writel_relaxed(readl_relaxed(pll->base + PLL_NUMERATOR),
306 			       pll->base + PLL_NUMERATOR);
307 
308 	val |= CLKMUX_BYPASS;
309 	writel_relaxed(val, pll->base + PLL_CTRL);
310 
311 	val |= POWERUP_MASK;
312 	writel_relaxed(val, pll->base + PLL_CTRL);
313 	readl(pll->base + PLL_CTRL);
314 
315 	ret = clk_fracn_gppll_wait_lock(pll);
316 	if (ret)
317 		return ret;
318 
319 	val |= CLKMUX_EN;
320 	writel_relaxed(val, pll->base + PLL_CTRL);
321 
322 	val &= ~CLKMUX_BYPASS;
323 	writel_relaxed(val, pll->base + PLL_CTRL);
324 
325 	return 0;
326 }
327 
328 static int clk_fracn_gppll_is_prepared(struct clk_hw *hw)
329 {
330 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
331 	u32 val;
332 
333 	val = readl_relaxed(pll->base + PLL_CTRL);
334 
335 	return (val & POWERUP_MASK) ? 1 : 0;
336 }
337 
338 static void clk_fracn_gppll_unprepare(struct clk_hw *hw)
339 {
340 	struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw);
341 	u32 val;
342 
343 	val = readl_relaxed(pll->base + PLL_CTRL);
344 	val &= ~POWERUP_MASK;
345 	writel_relaxed(val, pll->base + PLL_CTRL);
346 }
347 
348 static const struct clk_ops clk_fracn_gppll_ops = {
349 	.prepare	= clk_fracn_gppll_prepare,
350 	.unprepare	= clk_fracn_gppll_unprepare,
351 	.is_prepared	= clk_fracn_gppll_is_prepared,
352 	.recalc_rate	= clk_fracn_gppll_recalc_rate,
353 	.determine_rate = clk_fracn_gppll_determine_rate,
354 	.set_rate	= clk_fracn_gppll_set_rate,
355 };
356 
357 static struct clk_hw *_imx_clk_fracn_gppll(const char *name, const char *parent_name,
358 					   void __iomem *base,
359 					   const struct imx_fracn_gppll_clk *pll_clk,
360 					   u32 pll_flags)
361 {
362 	struct clk_fracn_gppll *pll;
363 	struct clk_hw *hw;
364 	struct clk_init_data init;
365 	int ret;
366 
367 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
368 	if (!pll)
369 		return ERR_PTR(-ENOMEM);
370 
371 	init.name = name;
372 	init.flags = pll_clk->flags;
373 	init.parent_names = &parent_name;
374 	init.num_parents = 1;
375 	init.ops = &clk_fracn_gppll_ops;
376 
377 	pll->base = base;
378 	pll->hw.init = &init;
379 	pll->rate_table = pll_clk->rate_table;
380 	pll->rate_count = pll_clk->rate_count;
381 	pll->flags = pll_flags;
382 
383 	hw = &pll->hw;
384 
385 	ret = clk_hw_register(NULL, hw);
386 	if (ret) {
387 		pr_err("%s: failed to register pll %s %d\n", __func__, name, ret);
388 		kfree(pll);
389 		return ERR_PTR(ret);
390 	}
391 
392 	return hw;
393 }
394 
395 struct clk_hw *imx_clk_fracn_gppll(const char *name, const char *parent_name, void __iomem *base,
396 				   const struct imx_fracn_gppll_clk *pll_clk)
397 {
398 	return _imx_clk_fracn_gppll(name, parent_name, base, pll_clk, CLK_FRACN_GPPLL_FRACN);
399 }
400 EXPORT_SYMBOL_GPL(imx_clk_fracn_gppll);
401 
402 struct clk_hw *imx_clk_fracn_gppll_integer(const char *name, const char *parent_name,
403 					   void __iomem *base,
404 					   const struct imx_fracn_gppll_clk *pll_clk)
405 {
406 	return _imx_clk_fracn_gppll(name, parent_name, base, pll_clk, CLK_FRACN_GPPLL_INTEGER);
407 }
408 EXPORT_SYMBOL_GPL(imx_clk_fracn_gppll_integer);
409