xref: /freebsd/sys/arm/ti/clk/ti_clk_dpll.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Emmanuel Vadot <manu@freebsd.org>
5  *
6  * Copyright (c) 2020 Oskar Holmlund <oskar.holmlund@ohdata.se>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * based on sys/arm/allwinner/clkng/aw_clk_np.c
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 
39 #include <dev/extres/clk/clk.h>
40 
41 #include <arm/ti/clk/ti_clk_dpll.h>
42 
43 #include "clkdev_if.h"
44 
45 /*
46  * clknode for clocks matching the formula :
47  *
48  * clk = clkin * n / p
49  *
50  */
51 
52 struct ti_dpll_clknode_sc {
53 	uint32_t		ti_clkmode_offset; /* control */
54 	uint8_t			ti_clkmode_flags;
55 
56 	uint32_t		ti_idlest_offset;
57 
58 	uint32_t		ti_clksel_offset; /* mult-div1 */
59 	struct ti_clk_factor	n; /* ti_clksel_mult */
60 	struct ti_clk_factor	p; /* ti_clksel_div */
61 
62 	uint32_t		ti_autoidle_offset;
63 };
64 
65 #define	WRITE4(_clk, off, val)						\
66 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
67 #define	READ4(_clk, off, val)						\
68 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
69 #define	DEVICE_LOCK(_clk)						\
70 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
71 #define	DEVICE_UNLOCK(_clk)						\
72 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
73 
74 static int
75 ti_dpll_clk_init(struct clknode *clk, device_t dev)
76 {
77 	clknode_init_parent_idx(clk, 0);
78 	return (0);
79 }
80 
81 /* helper to keep aw_clk_np_find_best "intact" */
82 static inline uint32_t
83 ti_clk_factor_get_max(struct ti_clk_factor *factor)
84 {
85 	uint32_t max;
86 
87 	if (factor->flags & TI_CLK_FACTOR_FIXED)
88 		max = factor->value;
89 	else {
90 		max = (1 << factor->width);
91 	}
92 
93 	return (max);
94 }
95 
96 static inline uint32_t
97 ti_clk_factor_get_min(struct ti_clk_factor *factor)
98 {
99 	uint32_t min;
100 
101 	if (factor->flags & TI_CLK_FACTOR_FIXED)
102 		min = factor->value;
103 	else if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
104 		min = 0;
105 	else if (factor->flags & TI_CLK_FACTOR_MIN_VALUE)
106 		min = factor->min_value;
107 	else
108 		min = 1;
109 
110 	return (min);
111 }
112 
113 static uint64_t
114 ti_dpll_clk_find_best(struct ti_dpll_clknode_sc *sc, uint64_t fparent,
115 	uint64_t *fout, uint32_t *factor_n, uint32_t *factor_p)
116 {
117 	uint64_t cur, best;
118 	uint32_t n, p, max_n, max_p, min_n, min_p;
119 
120 	*factor_n = *factor_p = 0;
121 
122 	max_n = ti_clk_factor_get_max(&sc->n);
123 	max_p = ti_clk_factor_get_max(&sc->p);
124 	min_n = ti_clk_factor_get_min(&sc->n);
125 	min_p = ti_clk_factor_get_min(&sc->p);
126 
127 	for (p = min_p; p <= max_p; ) {
128 		for (n = min_n; n <= max_n; ) {
129 			cur = fparent * n / p;
130 			if (abs(*fout - cur) < abs(*fout - best)) {
131 				best = cur;
132 				*factor_n = n;
133 				*factor_p = p;
134 			}
135 
136 			n++;
137 		}
138 		p++;
139 	}
140 
141 	return (best);
142 }
143 
144 static inline uint32_t
145 ti_clk_get_factor(uint32_t val, struct ti_clk_factor *factor)
146 {
147 	uint32_t factor_val;
148 
149 	if (factor->flags & TI_CLK_FACTOR_FIXED)
150 		return (factor->value);
151 
152 	factor_val = (val & factor->mask) >> factor->shift;
153 	if (!(factor->flags & TI_CLK_FACTOR_ZERO_BASED))
154 		factor_val += 1;
155 
156 	return (factor_val);
157 }
158 
159 static inline uint32_t
160 ti_clk_factor_get_value(struct ti_clk_factor *factor, uint32_t raw)
161 {
162 	uint32_t val;
163 
164 	if (factor->flags & TI_CLK_FACTOR_FIXED)
165 		return (factor->value);
166 
167 	if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
168 		val = raw;
169 	else if (factor->flags & TI_CLK_FACTOR_MAX_VALUE &&
170 	    raw > factor->max_value)
171 		val = factor->max_value;
172 	else
173 		val = raw - 1;
174 
175 	return (val);
176 }
177 
178 static int
179 ti_dpll_clk_set_freq(struct clknode *clk, uint64_t fparent, uint64_t *fout,
180     int flags, int *stop)
181 {
182 	struct ti_dpll_clknode_sc *sc;
183 	uint64_t cur, best;
184 	uint32_t val, n, p, best_n, best_p, timeout;
185 
186 	sc = clknode_get_softc(clk);
187 
188 	best = cur = 0;
189 
190 	best = ti_dpll_clk_find_best(sc, fparent, fout,
191 	    &best_n, &best_p);
192 
193 	if ((flags & CLK_SET_DRYRUN) != 0) {
194 		*fout = best;
195 		*stop = 1;
196 		return (0);
197 	}
198 
199 	if ((best < *fout) &&
200 	  (flags == CLK_SET_ROUND_DOWN)) {
201 		*stop = 1;
202 		return (ERANGE);
203 	}
204 	if ((best > *fout) &&
205 	  (flags == CLK_SET_ROUND_UP)) {
206 		*stop = 1;
207 		return (ERANGE);
208 	}
209 
210 	DEVICE_LOCK(clk);
211 	/* 1 switch PLL to bypass mode */
212 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_MN_BYPASS_MODE);
213 
214 	/* 2 Ensure PLL is in bypass */
215 	timeout = 10000;
216 	do {
217 		DELAY(10);
218 		READ4(clk, sc->ti_idlest_offset, &val);
219 	} while (!(val & ST_MN_BYPASS_MASK) && timeout--);
220 
221 	if (timeout == 0) {
222 		DEVICE_UNLOCK(clk);
223 		return (ERANGE); // FIXME: Better return value?
224 	}
225 
226 	/* 3 Set DPLL_MULT & DPLL_DIV bits */
227 	READ4(clk, sc->ti_clksel_offset, &val);
228 
229 	n = ti_clk_factor_get_value(&sc->n, best_n);
230 	p = ti_clk_factor_get_value(&sc->p, best_p);
231 	val &= ~sc->n.mask;
232 	val &= ~sc->p.mask;
233 	val |= n << sc->n.shift;
234 	val |= p << sc->p.shift;
235 
236 	WRITE4(clk, sc->ti_clksel_offset, val);
237 
238 	/* 4. configure M2, M4, M5 and M6 */
239 	/*
240 	 * FIXME: According to documentation M2/M4/M5/M6 can be set "later"
241 	 * See note in TRM 8.1.6.7.1
242 	 */
243 
244 	/* 5 Switch over to lock mode */
245 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_LOCK_MODE);
246 
247 	/* 6 Ensure PLL is locked */
248 	timeout = 10000;
249 	do {
250 		DELAY(10);
251 		READ4(clk, sc->ti_idlest_offset, &val);
252 	} while (!(val & ST_DPLL_CLK_MASK) && timeout--);
253 
254 	DEVICE_UNLOCK(clk);
255 	if (timeout == 0) {
256 		return (ERANGE); // FIXME: Better return value?
257 	}
258 
259 	*fout = best;
260 	*stop = 1;
261 
262 	return (0);
263 }
264 
265 static int
266 ti_dpll_clk_recalc(struct clknode *clk, uint64_t *freq)
267 {
268 	struct ti_dpll_clknode_sc *sc;
269 	uint32_t val, n, p;
270 
271 	sc = clknode_get_softc(clk);
272 
273 	DEVICE_LOCK(clk);
274 	READ4(clk, sc->ti_clksel_offset, &val);
275 	DEVICE_UNLOCK(clk);
276 
277 	n = ti_clk_get_factor(val, &sc->n);
278 	p = ti_clk_get_factor(val, &sc->p);
279 
280 	*freq = *freq * n / p;
281 
282 	return (0);
283 }
284 
285 static clknode_method_t ti_dpll_clknode_methods[] = {
286 	/* Device interface */
287 	CLKNODEMETHOD(clknode_init,		ti_dpll_clk_init),
288 	CLKNODEMETHOD(clknode_recalc_freq,	ti_dpll_clk_recalc),
289 	CLKNODEMETHOD(clknode_set_freq,		ti_dpll_clk_set_freq),
290 	CLKNODEMETHOD_END
291 };
292 
293 DEFINE_CLASS_1(ti_dpll_clknode, ti_dpll_clknode_class, ti_dpll_clknode_methods,
294 	sizeof(struct ti_dpll_clknode_sc), clknode_class);
295 
296 int
297 ti_clknode_dpll_register(struct clkdom *clkdom, struct ti_clk_dpll_def *clkdef)
298 {
299 	struct clknode *clk;
300 	struct ti_dpll_clknode_sc *sc;
301 
302 	clk = clknode_create(clkdom, &ti_dpll_clknode_class, &clkdef->clkdef);
303 	if (clk == NULL)
304 		return (1);
305 
306 	sc = clknode_get_softc(clk);
307 
308 	sc->ti_clkmode_offset = clkdef->ti_clkmode_offset;
309 	sc->ti_clkmode_flags = clkdef->ti_clkmode_flags;
310 	sc->ti_idlest_offset = clkdef->ti_idlest_offset;
311 	sc->ti_clksel_offset = clkdef->ti_clksel_offset;
312 
313 	sc->n.shift = clkdef->ti_clksel_mult.shift;
314 	sc->n.mask = clkdef->ti_clksel_mult.mask;
315 	sc->n.width = clkdef->ti_clksel_mult.width;
316 	sc->n.value = clkdef->ti_clksel_mult.value;
317 	sc->n.min_value = clkdef->ti_clksel_mult.min_value;
318 	sc->n.max_value = clkdef->ti_clksel_mult.max_value;
319 	sc->n.flags = clkdef->ti_clksel_mult.flags;
320 
321 	sc->p.shift = clkdef->ti_clksel_div.shift;
322 	sc->p.mask = clkdef->ti_clksel_div.mask;
323 	sc->p.width = clkdef->ti_clksel_div.width;
324 	sc->p.value = clkdef->ti_clksel_div.value;
325 	sc->p.min_value = clkdef->ti_clksel_div.min_value;
326 	sc->p.max_value = clkdef->ti_clksel_div.max_value;
327 	sc->p.flags = clkdef->ti_clksel_div.flags;
328 
329 	sc->ti_autoidle_offset = clkdef->ti_autoidle_offset;
330 
331 	clknode_register(clkdom, clk);
332 
333 	return (0);
334 }
335