xref: /freebsd/sys/arm/ti/clk/ti_clk_dpll.c (revision 6be3386466ab79a84b48429ae66244f21526d3df) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/bus.h>
40 
41 #include <dev/extres/clk/clk.h>
42 
43 #include <arm/ti/clk/ti_clk_dpll.h>
44 
45 #include "clkdev_if.h"
46 
47 /*
48  * clknode for clocks matching the formula :
49  *
50  * clk = clkin * n / p
51  *
52  */
53 
54 struct ti_dpll_clknode_sc {
55 	uint32_t		ti_clkmode_offset; /* control */
56 	uint8_t			ti_clkmode_flags;
57 
58 	uint32_t		ti_idlest_offset;
59 
60 	uint32_t		ti_clksel_offset; /* mult-div1 */
61 	struct ti_clk_factor	n; /* ti_clksel_mult */
62 	struct ti_clk_factor	p; /* ti_clksel_div */
63 
64 	uint32_t		ti_autoidle_offset;
65 };
66 
67 #define	WRITE4(_clk, off, val)						\
68 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
69 #define	READ4(_clk, off, val)						\
70 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
71 #define	DEVICE_LOCK(_clk)						\
72 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
73 #define	DEVICE_UNLOCK(_clk)						\
74 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
75 
76 static int
77 ti_dpll_clk_init(struct clknode *clk, device_t dev)
78 {
79 	struct ti_dpll_clknode_sc *sc;
80 
81 	sc = clknode_get_softc(clk);
82 
83 	clknode_init_parent_idx(clk, 0);
84 	return (0);
85 }
86 
87 /* helper to keep aw_clk_np_find_best "intact" */
88 static inline uint32_t
89 ti_clk_factor_get_max(struct ti_clk_factor *factor)
90 {
91 	uint32_t max;
92 
93 	if (factor->flags & TI_CLK_FACTOR_FIXED)
94 		max = factor->value;
95 	else {
96 		max = (1 << factor->width);
97 	}
98 
99 	return (max);
100 }
101 
102 static inline uint32_t
103 ti_clk_factor_get_min(struct ti_clk_factor *factor)
104 {
105 	uint32_t min;
106 
107 	if (factor->flags & TI_CLK_FACTOR_FIXED)
108 		min = factor->value;
109 	else if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
110 		min = 0;
111 	else if (factor->flags & TI_CLK_FACTOR_MIN_VALUE)
112 		min = factor->min_value;
113 	else
114 		min = 1;
115 
116 	return (min);
117 }
118 
119 static uint64_t
120 ti_dpll_clk_find_best(struct ti_dpll_clknode_sc *sc, uint64_t fparent,
121 	uint64_t *fout, uint32_t *factor_n, uint32_t *factor_p)
122 {
123 	uint64_t cur, best;
124 	uint32_t n, p, max_n, max_p, min_n, min_p;
125 
126 	*factor_n = *factor_p = 0;
127 
128 	max_n = ti_clk_factor_get_max(&sc->n);
129 	max_p = ti_clk_factor_get_max(&sc->p);
130 	min_n = ti_clk_factor_get_min(&sc->n);
131 	min_p = ti_clk_factor_get_min(&sc->p);
132 
133 	for (p = min_p; p <= max_p; ) {
134 		for (n = min_n; n <= max_n; ) {
135 			cur = fparent * n / p;
136 			if (abs(*fout - cur) < abs(*fout - best)) {
137 				best = cur;
138 				*factor_n = n;
139 				*factor_p = p;
140 			}
141 
142 			n++;
143 		}
144 		p++;
145 	}
146 
147 	return (best);
148 }
149 
150 static inline uint32_t
151 ti_clk_get_factor(uint32_t val, struct ti_clk_factor *factor)
152 {
153 	uint32_t factor_val;
154 
155 	if (factor->flags & TI_CLK_FACTOR_FIXED)
156 		return (factor->value);
157 
158 	factor_val = (val & factor->mask) >> factor->shift;
159 	if (!(factor->flags & TI_CLK_FACTOR_ZERO_BASED))
160 		factor_val += 1;
161 
162 	return (factor_val);
163 }
164 
165 static inline uint32_t
166 ti_clk_factor_get_value(struct ti_clk_factor *factor, uint32_t raw)
167 {
168 	uint32_t val;
169 
170 	if (factor->flags & TI_CLK_FACTOR_FIXED)
171 		return (factor->value);
172 
173 	if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
174 		val = raw;
175 	else if (factor->flags & TI_CLK_FACTOR_MAX_VALUE &&
176 	    raw > factor->max_value)
177 		val = factor->max_value;
178 	else
179 		val = raw - 1;
180 
181 	return (val);
182 }
183 
184 static int
185 ti_dpll_clk_set_freq(struct clknode *clk, uint64_t fparent, uint64_t *fout,
186     int flags, int *stop)
187 {
188 	struct ti_dpll_clknode_sc *sc;
189 	uint64_t cur, best;
190 	uint32_t val, n, p, best_n, best_p, timeout;
191 
192 	sc = clknode_get_softc(clk);
193 
194 	best = cur = 0;
195 
196 	best = ti_dpll_clk_find_best(sc, fparent, fout,
197 	    &best_n, &best_p);
198 
199 	if ((flags & CLK_SET_DRYRUN) != 0) {
200 		*fout = best;
201 		*stop = 1;
202 		return (0);
203 	}
204 
205 	if ((best < *fout) &&
206 	  (flags == CLK_SET_ROUND_DOWN)) {
207 		*stop = 1;
208 		return (ERANGE);
209 	}
210 	if ((best > *fout) &&
211 	  (flags == CLK_SET_ROUND_UP)) {
212 		*stop = 1;
213 		return (ERANGE);
214 	}
215 
216 	DEVICE_LOCK(clk);
217 	/* 1 switch PLL to bypass mode */
218 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_MN_BYPASS_MODE);
219 
220 	/* 2 Ensure PLL is in bypass */
221 	timeout = 10000;
222 	do {
223 		DELAY(10);
224 		READ4(clk, sc->ti_idlest_offset, &val);
225 	} while (!(val & ST_MN_BYPASS_MASK) && timeout--);
226 
227 	if (timeout == 0) {
228 		DEVICE_UNLOCK(clk);
229 		return (ERANGE); // FIXME: Better return value?
230 	}
231 
232 	/* 3 Set DPLL_MULT & DPLL_DIV bits */
233 	READ4(clk, sc->ti_clksel_offset, &val);
234 
235 	n = ti_clk_factor_get_value(&sc->n, best_n);
236 	p = ti_clk_factor_get_value(&sc->p, best_p);
237 	val &= ~sc->n.mask;
238 	val &= ~sc->p.mask;
239 	val |= n << sc->n.shift;
240 	val |= p << sc->p.shift;
241 
242 	WRITE4(clk, sc->ti_clksel_offset, val);
243 
244 	/* 4. configure M2, M4, M5 and M6 */
245 	/*
246 	 * FIXME: According to documentation M2/M4/M5/M6 can be set "later"
247 	 * See note in TRM 8.1.6.7.1
248 	 */
249 
250 	/* 5 Switch over to lock mode */
251 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_LOCK_MODE);
252 
253 	/* 6 Ensure PLL is locked */
254 	timeout = 10000;
255 	do {
256 		DELAY(10);
257 		READ4(clk, sc->ti_idlest_offset, &val);
258 	} while (!(val & ST_DPLL_CLK_MASK) && timeout--);
259 
260 	DEVICE_UNLOCK(clk);
261 	if (timeout == 0) {
262 		return (ERANGE); // FIXME: Better return value?
263 	}
264 
265 	*fout = best;
266 	*stop = 1;
267 
268 	return (0);
269 }
270 
271 static int
272 ti_dpll_clk_recalc(struct clknode *clk, uint64_t *freq)
273 {
274 	struct ti_dpll_clknode_sc *sc;
275 	uint32_t val, n, p;
276 
277 	sc = clknode_get_softc(clk);
278 
279 	DEVICE_LOCK(clk);
280 	READ4(clk, sc->ti_clksel_offset, &val);
281 	DEVICE_UNLOCK(clk);
282 
283 	n = ti_clk_get_factor(val, &sc->n);
284 	p = ti_clk_get_factor(val, &sc->p);
285 
286 	*freq = *freq * n / p;
287 
288 	return (0);
289 }
290 
291 static clknode_method_t ti_dpll_clknode_methods[] = {
292 	/* Device interface */
293 	CLKNODEMETHOD(clknode_init,		ti_dpll_clk_init),
294 	CLKNODEMETHOD(clknode_recalc_freq,	ti_dpll_clk_recalc),
295 	CLKNODEMETHOD(clknode_set_freq,		ti_dpll_clk_set_freq),
296 	CLKNODEMETHOD_END
297 };
298 
299 DEFINE_CLASS_1(ti_dpll_clknode, ti_dpll_clknode_class, ti_dpll_clknode_methods,
300 	sizeof(struct ti_dpll_clknode_sc), clknode_class);
301 
302 int
303 ti_clknode_dpll_register(struct clkdom *clkdom, struct ti_clk_dpll_def *clkdef)
304 {
305 	struct clknode *clk;
306 	struct ti_dpll_clknode_sc *sc;
307 
308 	clk = clknode_create(clkdom, &ti_dpll_clknode_class, &clkdef->clkdef);
309 	if (clk == NULL)
310 		return (1);
311 
312 	sc = clknode_get_softc(clk);
313 
314 	sc->ti_clkmode_offset = clkdef->ti_clkmode_offset;
315 	sc->ti_clkmode_flags = clkdef->ti_clkmode_flags;
316 	sc->ti_idlest_offset = clkdef->ti_idlest_offset;
317 	sc->ti_clksel_offset = clkdef->ti_clksel_offset;
318 
319 	sc->n.shift = clkdef->ti_clksel_mult.shift;
320 	sc->n.mask = clkdef->ti_clksel_mult.mask;
321 	sc->n.width = clkdef->ti_clksel_mult.width;
322 	sc->n.value = clkdef->ti_clksel_mult.value;
323 	sc->n.min_value = clkdef->ti_clksel_mult.min_value;
324 	sc->n.max_value = clkdef->ti_clksel_mult.max_value;
325 	sc->n.flags = clkdef->ti_clksel_mult.flags;
326 
327 	sc->p.shift = clkdef->ti_clksel_div.shift;
328 	sc->p.mask = clkdef->ti_clksel_div.mask;
329 	sc->p.width = clkdef->ti_clksel_div.width;
330 	sc->p.value = clkdef->ti_clksel_div.value;
331 	sc->p.min_value = clkdef->ti_clksel_div.min_value;
332 	sc->p.max_value = clkdef->ti_clksel_div.max_value;
333 	sc->p.flags = clkdef->ti_clksel_div.flags;
334 
335 	sc->ti_autoidle_offset = clkdef->ti_autoidle_offset;
336 
337 	clknode_register(clkdom, clk);
338 
339 	return (0);
340 }
341