xref: /freebsd/sys/arm/ti/clk/ti_clk_dpll.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
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/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 
36 #include <dev/clk/clk.h>
37 
38 #include <arm/ti/clk/ti_clk_dpll.h>
39 
40 #include "clkdev_if.h"
41 
42 /*
43  * clknode for clocks matching the formula :
44  *
45  * clk = clkin * n / p
46  *
47  */
48 
49 struct ti_dpll_clknode_sc {
50 	uint32_t		ti_clkmode_offset; /* control */
51 	uint8_t			ti_clkmode_flags;
52 
53 	uint32_t		ti_idlest_offset;
54 
55 	uint32_t		ti_clksel_offset; /* mult-div1 */
56 	struct ti_clk_factor	n; /* ti_clksel_mult */
57 	struct ti_clk_factor	p; /* ti_clksel_div */
58 
59 	uint32_t		ti_autoidle_offset;
60 };
61 
62 #define	WRITE4(_clk, off, val)						\
63 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
64 #define	READ4(_clk, off, val)						\
65 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
66 #define	DEVICE_LOCK(_clk)						\
67 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
68 #define	DEVICE_UNLOCK(_clk)						\
69 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
70 
71 static int
72 ti_dpll_clk_init(struct clknode *clk, device_t dev)
73 {
74 	clknode_init_parent_idx(clk, 0);
75 	return (0);
76 }
77 
78 /* helper to keep aw_clk_np_find_best "intact" */
79 static inline uint32_t
80 ti_clk_factor_get_max(struct ti_clk_factor *factor)
81 {
82 	uint32_t max;
83 
84 	if (factor->flags & TI_CLK_FACTOR_FIXED)
85 		max = factor->value;
86 	else {
87 		max = (1 << factor->width);
88 	}
89 
90 	return (max);
91 }
92 
93 static inline uint32_t
94 ti_clk_factor_get_min(struct ti_clk_factor *factor)
95 {
96 	uint32_t min;
97 
98 	if (factor->flags & TI_CLK_FACTOR_FIXED)
99 		min = factor->value;
100 	else if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
101 		min = 0;
102 	else if (factor->flags & TI_CLK_FACTOR_MIN_VALUE)
103 		min = factor->min_value;
104 	else
105 		min = 1;
106 
107 	return (min);
108 }
109 
110 static uint64_t
111 ti_dpll_clk_find_best(struct ti_dpll_clknode_sc *sc, uint64_t fparent,
112 	uint64_t *fout, uint32_t *factor_n, uint32_t *factor_p)
113 {
114 	uint64_t cur, best;
115 	uint32_t n, p, max_n, max_p, min_n, min_p;
116 
117 	*factor_n = *factor_p = 0;
118 
119 	max_n = ti_clk_factor_get_max(&sc->n);
120 	max_p = ti_clk_factor_get_max(&sc->p);
121 	min_n = ti_clk_factor_get_min(&sc->n);
122 	min_p = ti_clk_factor_get_min(&sc->p);
123 
124 	for (p = min_p; p <= max_p; ) {
125 		for (n = min_n; n <= max_n; ) {
126 			cur = fparent * n / p;
127 			if (abs(*fout - cur) < abs(*fout - best)) {
128 				best = cur;
129 				*factor_n = n;
130 				*factor_p = p;
131 			}
132 
133 			n++;
134 		}
135 		p++;
136 	}
137 
138 	return (best);
139 }
140 
141 static inline uint32_t
142 ti_clk_get_factor(uint32_t val, struct ti_clk_factor *factor)
143 {
144 	uint32_t factor_val;
145 
146 	if (factor->flags & TI_CLK_FACTOR_FIXED)
147 		return (factor->value);
148 
149 	factor_val = (val & factor->mask) >> factor->shift;
150 	if (!(factor->flags & TI_CLK_FACTOR_ZERO_BASED))
151 		factor_val += 1;
152 
153 	return (factor_val);
154 }
155 
156 static inline uint32_t
157 ti_clk_factor_get_value(struct ti_clk_factor *factor, uint32_t raw)
158 {
159 	uint32_t val;
160 
161 	if (factor->flags & TI_CLK_FACTOR_FIXED)
162 		return (factor->value);
163 
164 	if (factor->flags & TI_CLK_FACTOR_ZERO_BASED)
165 		val = raw;
166 	else if (factor->flags & TI_CLK_FACTOR_MAX_VALUE &&
167 	    raw > factor->max_value)
168 		val = factor->max_value;
169 	else
170 		val = raw - 1;
171 
172 	return (val);
173 }
174 
175 static int
176 ti_dpll_clk_set_freq(struct clknode *clk, uint64_t fparent, uint64_t *fout,
177     int flags, int *stop)
178 {
179 	struct ti_dpll_clknode_sc *sc;
180 	uint64_t cur, best;
181 	uint32_t val, n, p, best_n, best_p, timeout;
182 
183 	sc = clknode_get_softc(clk);
184 
185 	best = cur = 0;
186 
187 	best = ti_dpll_clk_find_best(sc, fparent, fout,
188 	    &best_n, &best_p);
189 
190 	if ((flags & CLK_SET_DRYRUN) != 0) {
191 		*fout = best;
192 		*stop = 1;
193 		return (0);
194 	}
195 
196 	if ((best < *fout) &&
197 	  (flags == CLK_SET_ROUND_DOWN)) {
198 		*stop = 1;
199 		return (ERANGE);
200 	}
201 	if ((best > *fout) &&
202 	  (flags == CLK_SET_ROUND_UP)) {
203 		*stop = 1;
204 		return (ERANGE);
205 	}
206 
207 	DEVICE_LOCK(clk);
208 	/* 1 switch PLL to bypass mode */
209 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_MN_BYPASS_MODE);
210 
211 	/* 2 Ensure PLL is in bypass */
212 	timeout = 10000;
213 	do {
214 		DELAY(10);
215 		READ4(clk, sc->ti_idlest_offset, &val);
216 	} while (!(val & ST_MN_BYPASS_MASK) && timeout--);
217 
218 	if (timeout == 0) {
219 		DEVICE_UNLOCK(clk);
220 		return (ERANGE); // FIXME: Better return value?
221 	}
222 
223 	/* 3 Set DPLL_MULT & DPLL_DIV bits */
224 	READ4(clk, sc->ti_clksel_offset, &val);
225 
226 	n = ti_clk_factor_get_value(&sc->n, best_n);
227 	p = ti_clk_factor_get_value(&sc->p, best_p);
228 	val &= ~sc->n.mask;
229 	val &= ~sc->p.mask;
230 	val |= n << sc->n.shift;
231 	val |= p << sc->p.shift;
232 
233 	WRITE4(clk, sc->ti_clksel_offset, val);
234 
235 	/* 4. configure M2, M4, M5 and M6 */
236 	/*
237 	 * FIXME: According to documentation M2/M4/M5/M6 can be set "later"
238 	 * See note in TRM 8.1.6.7.1
239 	 */
240 
241 	/* 5 Switch over to lock mode */
242 	WRITE4(clk, sc->ti_clkmode_offset, DPLL_EN_LOCK_MODE);
243 
244 	/* 6 Ensure PLL is locked */
245 	timeout = 10000;
246 	do {
247 		DELAY(10);
248 		READ4(clk, sc->ti_idlest_offset, &val);
249 	} while (!(val & ST_DPLL_CLK_MASK) && timeout--);
250 
251 	DEVICE_UNLOCK(clk);
252 	if (timeout == 0) {
253 		return (ERANGE); // FIXME: Better return value?
254 	}
255 
256 	*fout = best;
257 	*stop = 1;
258 
259 	return (0);
260 }
261 
262 static int
263 ti_dpll_clk_recalc(struct clknode *clk, uint64_t *freq)
264 {
265 	struct ti_dpll_clknode_sc *sc;
266 	uint32_t val, n, p;
267 
268 	sc = clknode_get_softc(clk);
269 
270 	DEVICE_LOCK(clk);
271 	READ4(clk, sc->ti_clksel_offset, &val);
272 	DEVICE_UNLOCK(clk);
273 
274 	n = ti_clk_get_factor(val, &sc->n);
275 	p = ti_clk_get_factor(val, &sc->p);
276 
277 	*freq = *freq * n / p;
278 
279 	return (0);
280 }
281 
282 static clknode_method_t ti_dpll_clknode_methods[] = {
283 	/* Device interface */
284 	CLKNODEMETHOD(clknode_init,		ti_dpll_clk_init),
285 	CLKNODEMETHOD(clknode_recalc_freq,	ti_dpll_clk_recalc),
286 	CLKNODEMETHOD(clknode_set_freq,		ti_dpll_clk_set_freq),
287 	CLKNODEMETHOD_END
288 };
289 
290 DEFINE_CLASS_1(ti_dpll_clknode, ti_dpll_clknode_class, ti_dpll_clknode_methods,
291 	sizeof(struct ti_dpll_clknode_sc), clknode_class);
292 
293 int
294 ti_clknode_dpll_register(struct clkdom *clkdom, struct ti_clk_dpll_def *clkdef)
295 {
296 	struct clknode *clk;
297 	struct ti_dpll_clknode_sc *sc;
298 
299 	clk = clknode_create(clkdom, &ti_dpll_clknode_class, &clkdef->clkdef);
300 	if (clk == NULL)
301 		return (1);
302 
303 	sc = clknode_get_softc(clk);
304 
305 	sc->ti_clkmode_offset = clkdef->ti_clkmode_offset;
306 	sc->ti_clkmode_flags = clkdef->ti_clkmode_flags;
307 	sc->ti_idlest_offset = clkdef->ti_idlest_offset;
308 	sc->ti_clksel_offset = clkdef->ti_clksel_offset;
309 
310 	sc->n.shift = clkdef->ti_clksel_mult.shift;
311 	sc->n.mask = clkdef->ti_clksel_mult.mask;
312 	sc->n.width = clkdef->ti_clksel_mult.width;
313 	sc->n.value = clkdef->ti_clksel_mult.value;
314 	sc->n.min_value = clkdef->ti_clksel_mult.min_value;
315 	sc->n.max_value = clkdef->ti_clksel_mult.max_value;
316 	sc->n.flags = clkdef->ti_clksel_mult.flags;
317 
318 	sc->p.shift = clkdef->ti_clksel_div.shift;
319 	sc->p.mask = clkdef->ti_clksel_div.mask;
320 	sc->p.width = clkdef->ti_clksel_div.width;
321 	sc->p.value = clkdef->ti_clksel_div.value;
322 	sc->p.min_value = clkdef->ti_clksel_div.min_value;
323 	sc->p.max_value = clkdef->ti_clksel_div.max_value;
324 	sc->p.flags = clkdef->ti_clksel_div.flags;
325 
326 	sc->ti_autoidle_offset = clkdef->ti_autoidle_offset;
327 
328 	clknode_register(clkdom, clk);
329 
330 	return (0);
331 }
332