xref: /freebsd/sys/arm64/freescale/imx/clk/imx_clk_composite.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2018 Emmanuel Vadot <manu@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 
33 #include <dev/extres/clk/clk.h>
34 
35 #include <arm64/freescale/imx/clk/imx_clk_composite.h>
36 
37 #include "clkdev_if.h"
38 
39 #define	TARGET_ROOT_ENABLE	(1 << 28)
40 #define	TARGET_ROOT_MUX(n)	((n) << 24)
41 #define	TARGET_ROOT_MUX_MASK	(7 << 24)
42 #define	TARGET_ROOT_MUX_SHIFT	24
43 #define	TARGET_ROOT_PRE_PODF(n)		((((n) - 1) & 0x7) << 16)
44 #define	TARGET_ROOT_PRE_PODF_MASK	(0x7 << 16)
45 #define	TARGET_ROOT_PRE_PODF_SHIFT	16
46 #define	TARGET_ROOT_PRE_PODF_MAX	7
47 #define	TARGET_ROOT_POST_PODF(n)	((((n) - 1) & 0x3f) << 0)
48 #define	TARGET_ROOT_POST_PODF_MASK	(0x3f << 0)
49 #define	TARGET_ROOT_POST_PODF_SHIFT	0
50 #define	TARGET_ROOT_POST_PODF_MAX	0x3f
51 
52 struct imx_clk_composite_sc {
53 	uint32_t	offset;
54 	uint32_t	flags;
55 };
56 
57 #define	WRITE4(_clk, off, val)						\
58 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
59 #define	READ4(_clk, off, val)						\
60 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
61 #define	DEVICE_LOCK(_clk)						\
62 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
63 #define	DEVICE_UNLOCK(_clk)						\
64 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
65 
66 #define	IMX_CLK_COMPOSITE_MASK_SHIFT	16
67 
68 #if 0
69 #define	dprintf(format, arg...)						\
70 	printf("%s:(%s)" format, __func__, clknode_get_name(clk), arg)
71 #else
72 #define	dprintf(format, arg...)
73 #endif
74 
75 static int
76 imx_clk_composite_init(struct clknode *clk, device_t dev)
77 {
78 	struct imx_clk_composite_sc *sc;
79 	uint32_t val, idx;
80 
81 	sc = clknode_get_softc(clk);
82 
83 	DEVICE_LOCK(clk);
84 	READ4(clk, sc->offset, &val);
85 	DEVICE_UNLOCK(clk);
86 	idx = (val & TARGET_ROOT_MUX_MASK) >> TARGET_ROOT_MUX_SHIFT;
87 
88 	clknode_init_parent_idx(clk, idx);
89 
90 	return (0);
91 }
92 
93 static int
94 imx_clk_composite_set_gate(struct clknode *clk, bool enable)
95 {
96 	struct imx_clk_composite_sc *sc;
97 	uint32_t val = 0;
98 
99 	sc = clknode_get_softc(clk);
100 
101 	dprintf("%sabling gate\n", enable ? "En" : "Dis");
102 	DEVICE_LOCK(clk);
103 	READ4(clk, sc->offset, &val);
104 	if (enable)
105 		val |= TARGET_ROOT_ENABLE;
106 	else
107 		val &= ~(TARGET_ROOT_ENABLE);
108 	WRITE4(clk, sc->offset, val);
109 	DEVICE_UNLOCK(clk);
110 
111 	return (0);
112 }
113 
114 static int
115 imx_clk_composite_set_mux(struct clknode *clk, int index)
116 {
117 	struct imx_clk_composite_sc *sc;
118 	uint32_t val = 0;
119 
120 	sc = clknode_get_softc(clk);
121 
122 	dprintf("Set mux to %d\n", index);
123 	DEVICE_LOCK(clk);
124 	READ4(clk, sc->offset, &val);
125 	val &= ~(TARGET_ROOT_MUX_MASK);
126 	val |= TARGET_ROOT_MUX(index);
127 	WRITE4(clk, sc->offset, val);
128 	DEVICE_UNLOCK(clk);
129 
130 	return (0);
131 }
132 
133 static int
134 imx_clk_composite_recalc(struct clknode *clk, uint64_t *freq)
135 {
136 	struct imx_clk_composite_sc *sc;
137 	uint32_t reg, pre_div, post_div;
138 
139 	sc = clknode_get_softc(clk);
140 
141 	DEVICE_LOCK(clk);
142 	READ4(clk, sc->offset, &reg);
143 	DEVICE_UNLOCK(clk);
144 
145 	pre_div = ((reg & TARGET_ROOT_PRE_PODF_MASK)
146 	    >> TARGET_ROOT_PRE_PODF_SHIFT) + 1;
147 	post_div = ((reg & TARGET_ROOT_POST_PODF_MASK)
148 	    >> TARGET_ROOT_POST_PODF_SHIFT) + 1;
149 
150 	dprintf("parent_freq=%ju, div=%u\n", *freq, div);
151 	*freq = *freq / pre_div / post_div;
152 	dprintf("Final freq=%ju\n", *freq);
153 	return (0);
154 }
155 
156 static int
157 imx_clk_composite_find_best(uint64_t fparent, uint64_t ftarget,
158 	uint32_t *pre_div, uint32_t *post_div, int flags)
159 {
160 	uint32_t prediv, postdiv, best_prediv, best_postdiv;
161 	int64_t diff, best_diff;
162 	uint64_t cur;
163 
164 	best_diff = INT64_MAX;
165 	for (prediv = 1; prediv <= TARGET_ROOT_PRE_PODF_MAX + 1; prediv++) {
166 		for (postdiv = 1; postdiv <= TARGET_ROOT_POST_PODF_MAX + 1; postdiv++) {
167 			cur= fparent / prediv / postdiv;
168 			diff = (int64_t)ftarget - (int64_t)cur;
169 			if (flags & CLK_SET_ROUND_DOWN) {
170 				if (diff >= 0 && diff < best_diff) {
171 					best_diff = diff;
172 					best_prediv = prediv;
173 					best_postdiv = postdiv;
174 				}
175 			}
176 			else if (flags & CLK_SET_ROUND_UP) {
177 				if (diff <= 0 && abs(diff) < best_diff) {
178 					best_diff = diff;
179 					best_prediv = prediv;
180 					best_postdiv = postdiv;
181 				}
182 			}
183 			else {
184 				if (abs(diff) < best_diff) {
185 					best_diff = abs(diff);
186 					best_prediv = prediv;
187 					best_postdiv = postdiv;
188 				}
189 			}
190 		}
191 	}
192 
193 	if (best_diff == INT64_MAX)
194 		return (ERANGE);
195 
196 	*pre_div = best_prediv;
197 	*post_div = best_postdiv;
198 
199 	return (0);
200 }
201 
202 static int
203 imx_clk_composite_set_freq(struct clknode *clk, uint64_t fparent, uint64_t *fout,
204     int flags, int *stop)
205 {
206 	struct imx_clk_composite_sc *sc;
207 	struct clknode *p_clk;
208 	const char **p_names;
209 	int p_idx, best_parent;
210 	int64_t best_diff, diff;
211 	int32_t best_pre_div __unused, best_post_div __unused;
212 	int32_t pre_div, post_div;
213 	uint64_t cur, best;
214 	uint32_t val;
215 
216 	sc = clknode_get_softc(clk);
217 	dprintf("Finding best parent/div for target freq of %ju\n", *fout);
218 	p_names = clknode_get_parent_names(clk);
219 
220 	best_diff = 0;
221 
222 	for (p_idx = 0; p_idx != clknode_get_parents_num(clk); p_idx++) {
223 		p_clk = clknode_find_by_name(p_names[p_idx]);
224 		clknode_get_freq(p_clk, &fparent);
225 		dprintf("Testing with parent %s (%d) at freq %ju\n",
226 		    clknode_get_name(p_clk), p_idx, fparent);
227 
228 		if (!imx_clk_composite_find_best(fparent, *fout, &pre_div, &post_div, sc->flags))
229 			continue;
230 		cur = fparent / pre_div / post_div;
231 		diff = abs((int64_t)*fout - (int64_t)cur);
232 		if (diff < best_diff) {
233 			best = cur;
234 			best_diff = diff;
235 			best_pre_div = pre_div;
236 			best_post_div = post_div;
237 			best_parent = p_idx;
238 			dprintf("Best parent so far %s (%d) with best freq at "
239 			    "%ju\n", clknode_get_name(p_clk), p_idx, best);
240 		}
241 	}
242 
243 	*stop = 1;
244 	if (best_diff == INT64_MAX)
245 		return (ERANGE);
246 
247 	if ((flags & CLK_SET_DRYRUN) != 0) {
248 		*fout = best;
249 		return (0);
250 	}
251 
252 	p_idx = clknode_get_parent_idx(clk);
253 	if (p_idx != best_parent) {
254 		dprintf("Switching parent index from %d to %d\n", p_idx,
255 		    best_parent);
256 		clknode_set_parent_by_idx(clk, best_parent);
257 	}
258 
259 	dprintf("Setting dividers to pre=%d, post=%d\n", best_pre_div, best_post_div);
260 
261 	DEVICE_LOCK(clk);
262 	READ4(clk, sc->offset, &val);
263 	val &= ~(TARGET_ROOT_PRE_PODF_MASK | TARGET_ROOT_POST_PODF_MASK);
264 	val |= TARGET_ROOT_PRE_PODF(pre_div);
265 	val |= TARGET_ROOT_POST_PODF(post_div);
266 	DEVICE_UNLOCK(clk);
267 
268 	*fout = best;
269 	return (0);
270 }
271 
272 static clknode_method_t imx_clk_composite_clknode_methods[] = {
273 	/* Device interface */
274 	CLKNODEMETHOD(clknode_init,		imx_clk_composite_init),
275 	CLKNODEMETHOD(clknode_set_gate,		imx_clk_composite_set_gate),
276 	CLKNODEMETHOD(clknode_set_mux,		imx_clk_composite_set_mux),
277 	CLKNODEMETHOD(clknode_recalc_freq,	imx_clk_composite_recalc),
278 	CLKNODEMETHOD(clknode_set_freq,		imx_clk_composite_set_freq),
279 	CLKNODEMETHOD_END
280 };
281 
282 DEFINE_CLASS_1(imx_clk_composite_clknode, imx_clk_composite_clknode_class,
283     imx_clk_composite_clknode_methods, sizeof(struct imx_clk_composite_sc),
284     clknode_class);
285 
286 int
287 imx_clk_composite_register(struct clkdom *clkdom,
288     struct imx_clk_composite_def *clkdef)
289 {
290 	struct clknode *clk;
291 	struct imx_clk_composite_sc *sc;
292 
293 	clk = clknode_create(clkdom, &imx_clk_composite_clknode_class,
294 	    &clkdef->clkdef);
295 	if (clk == NULL)
296 		return (1);
297 
298 	sc = clknode_get_softc(clk);
299 
300 	sc->offset = clkdef->offset;
301 	sc->flags = clkdef->flags;
302 
303 	clknode_register(clkdom, clk);
304 
305 	return (0);
306 }
307