xref: /freebsd/sys/dev/clk/clk_div.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*-
2  * Copyright 2016 Michal Meloun <mmel@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/conf.h>
29 #include <sys/bus.h>
30 #include <sys/kernel.h>
31 #include <sys/systm.h>
32 
33 #include <machine/bus.h>
34 
35 #include <dev/clk/clk_div.h>
36 
37 #include "clkdev_if.h"
38 
39 #define	WR4(_clk, off, val)						\
40 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
41 #define	RD4(_clk, off, val)						\
42 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
43 #define	MD4(_clk, off, clr, set )					\
44 	CLKDEV_MODIFY_4(clknode_get_device(_clk), off, clr, set)
45 #define	DEVICE_LOCK(_clk)							\
46 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
47 #define	DEVICE_UNLOCK(_clk)						\
48 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
49 
50 static int clknode_div_init(struct clknode *clk, device_t dev);
51 static int clknode_div_recalc(struct clknode *clk, uint64_t *req);
52 static int clknode_div_set_freq(struct clknode *clknode, uint64_t fin,
53     uint64_t *fout, int flag, int *stop);
54 
55 struct clknode_div_sc {
56 	struct mtx	*mtx;
57 	struct resource *mem_res;
58 	uint32_t	offset;
59 	uint32_t	i_shift;
60 	uint32_t	i_mask;
61 	uint32_t	i_width;
62 	uint32_t	f_shift;
63 	uint32_t	f_mask;
64 	uint32_t	f_width;
65 	int		div_flags;
66 	uint32_t	divider;	/* in natural form */
67 
68 	struct clk_div_table	*div_table;
69 };
70 
71 static clknode_method_t clknode_div_methods[] = {
72 	/* Device interface */
73 	CLKNODEMETHOD(clknode_init,		clknode_div_init),
74 	CLKNODEMETHOD(clknode_recalc_freq,	clknode_div_recalc),
75 	CLKNODEMETHOD(clknode_set_freq,		clknode_div_set_freq),
76 	CLKNODEMETHOD_END
77 };
78 DEFINE_CLASS_1(clknode_div, clknode_div_class, clknode_div_methods,
79    sizeof(struct clknode_div_sc), clknode_class);
80 
81 static uint32_t
82 clknode_div_table_get_divider(struct clknode_div_sc *sc, uint32_t divider)
83 {
84 	struct clk_div_table *table;
85 
86 	if (!(sc->div_flags & CLK_DIV_WITH_TABLE))
87 		return (divider);
88 
89 	for (table = sc->div_table; table->divider != 0; table++)
90 		if (table->value == sc->divider)
91 			return (table->divider);
92 
93 	return (0);
94 }
95 
96 static int
97 clknode_div_table_get_value(struct clknode_div_sc *sc, uint32_t *divider)
98 {
99 	struct clk_div_table *table;
100 
101 	if (!(sc->div_flags & CLK_DIV_WITH_TABLE))
102 		return (0);
103 
104 	for (table = sc->div_table; table->divider != 0; table++)
105 		if (table->divider == *divider) {
106 			*divider = table->value;
107 			return (0);
108 		}
109 
110 	return (ENOENT);
111 }
112 
113 static int
114 clknode_div_init(struct clknode *clk, device_t dev)
115 {
116 	uint32_t reg;
117 	struct clknode_div_sc *sc;
118 	uint32_t i_div, f_div;
119 	int rv;
120 
121 	sc = clknode_get_softc(clk);
122 
123 	DEVICE_LOCK(clk);
124 	rv = RD4(clk, sc->offset, &reg);
125 	DEVICE_UNLOCK(clk);
126 	if (rv != 0)
127 		return (rv);
128 
129 	i_div = (reg >> sc->i_shift) & sc->i_mask;
130 	if (!(sc->div_flags & CLK_DIV_WITH_TABLE) &&
131 	    !(sc->div_flags & CLK_DIV_ZERO_BASED))
132 		i_div++;
133 	f_div = (reg >> sc->f_shift) & sc->f_mask;
134 	sc->divider = i_div << sc->f_width | f_div;
135 
136 	sc->divider = clknode_div_table_get_divider(sc, sc->divider);
137 	if (sc->divider == 0)
138 		panic("%s: divider is zero!\n", clknode_get_name(clk));
139 
140 	clknode_init_parent_idx(clk, 0);
141 	return(0);
142 }
143 
144 static int
145 clknode_div_recalc(struct clknode *clk, uint64_t *freq)
146 {
147 	struct clknode_div_sc *sc;
148 
149 	sc = clknode_get_softc(clk);
150 	if (sc->divider == 0) {
151 		printf("%s: %s divider is zero!\n", clknode_get_name(clk),
152 		__func__);
153 		*freq = 0;
154 		return(EINVAL);
155 	}
156 	*freq = (*freq << sc->f_width) / sc->divider;
157 	return (0);
158 }
159 
160 static int
161 clknode_div_set_freq(struct clknode *clk, uint64_t fin, uint64_t *fout,
162   int flags, int *stop)
163 {
164 	struct clknode_div_sc *sc;
165 	uint64_t divider, _fin, _fout;
166 	uint32_t reg, i_div, f_div, hw_i_div;
167 	int rv;
168 
169 	sc = clknode_get_softc(clk);
170 
171 	/* For fractional divider. */
172 	_fin = fin << sc->f_width;
173 	divider = (_fin + *fout / 2) / *fout;
174 	_fout = _fin / divider;
175 
176 	/* Rounding. */
177 	if ((flags & CLK_SET_ROUND_UP) && (*fout < _fout))
178 		divider--;
179 	else if ((flags & CLK_SET_ROUND_DOWN) && (*fout > _fout))
180 		divider++;
181 
182 	/* Break divider into integer and fractional parts. */
183 	i_div = divider >> sc->f_width;
184 	f_div = divider  & sc->f_mask;
185 
186 	if (i_div == 0) {
187 		printf("%s: %s integer divider is zero!\n",
188 		     clknode_get_name(clk), __func__);
189 		return(EINVAL);
190 	}
191 
192 	*stop = 1;
193 	hw_i_div = i_div;
194 	if (sc->div_flags & CLK_DIV_WITH_TABLE) {
195 		if (clknode_div_table_get_value(sc, &hw_i_div) != 0)
196 				return (ERANGE);
197 	} else {
198 		if (!(sc->div_flags & CLK_DIV_ZERO_BASED))
199 			hw_i_div--;
200 
201 		if (i_div > sc->i_mask) {
202 			/* XXX Pass to parent or return error? */
203 			printf("%s: %s integer divider is too big: %u\n",
204 			    clknode_get_name(clk), __func__, i_div);
205 			hw_i_div = sc->i_mask;
206 			*stop = 0;
207 		}
208 		i_div = hw_i_div;
209 		if (!(sc->div_flags & CLK_DIV_ZERO_BASED))
210 			i_div++;
211 	}
212 
213 	divider = i_div << sc->f_width | f_div;
214 
215 	if ((flags & CLK_SET_DRYRUN) == 0) {
216 		if ((*stop != 0) &&
217 		    ((flags & (CLK_SET_ROUND_UP | CLK_SET_ROUND_DOWN)) == 0) &&
218 		    (*fout != (_fin / divider)))
219 			return (ERANGE);
220 
221 		DEVICE_LOCK(clk);
222 		rv = MD4(clk, sc->offset,
223 		    (sc->i_mask << sc->i_shift) | (sc->f_mask << sc->f_shift),
224 		    (hw_i_div << sc->i_shift) | (f_div << sc->f_shift));
225 		if (rv != 0) {
226 			DEVICE_UNLOCK(clk);
227 			return (rv);
228 		}
229 		RD4(clk, sc->offset, &reg);
230 		DEVICE_UNLOCK(clk);
231 
232 		sc->divider = divider;
233 	}
234 
235 	*fout = _fin / divider;
236 	return (0);
237 }
238 
239 int
240 clknode_div_register(struct clkdom *clkdom, struct clk_div_def *clkdef)
241 {
242 	struct clknode *clk;
243 	struct clknode_div_sc *sc;
244 
245 	clk = clknode_create(clkdom, &clknode_div_class, &clkdef->clkdef);
246 	if (clk == NULL)
247 		return (1);
248 
249 	sc = clknode_get_softc(clk);
250 	sc->offset = clkdef->offset;
251 	sc->i_shift = clkdef->i_shift;
252 	sc->i_width = clkdef->i_width;
253 	sc->i_mask = (1 << clkdef->i_width) - 1;
254 	sc->f_shift = clkdef->f_shift;
255 	sc->f_width = clkdef->f_width;
256 	sc->f_mask = (1 << clkdef->f_width) - 1;
257 	sc->div_flags = clkdef->div_flags;
258 	sc->div_table = clkdef->div_table;
259 
260 	clknode_register(clkdom, clk);
261 	return (0);
262 }
263