xref: /freebsd/sys/dev/clk/rockchip/rk_clk_mux.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2016 Michal Meloun <mmel@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/conf.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/systm.h>
34 
35 #include <machine/bus.h>
36 
37 #include <dev/clk/clk.h>
38 #include <dev/syscon/syscon.h>
39 
40 #include <dev/clk/rockchip/rk_cru.h>
41 #include <dev/clk/rockchip/rk_clk_mux.h>
42 
43 #include "clkdev_if.h"
44 #include "syscon_if.h"
45 
46 #define	WR4(_clk, off, val)						\
47 	CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
48 #define	RD4(_clk, off, val)						\
49 	CLKDEV_READ_4(clknode_get_device(_clk), off, val)
50 #define	MD4(_clk, off, clr, set )					\
51 	CLKDEV_MODIFY_4(clknode_get_device(_clk), off, clr, set)
52 #define	DEVICE_LOCK(_clk)						\
53 	CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
54 #define	DEVICE_UNLOCK(_clk)						\
55 	CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))
56 
57 #if 0
58 #define	dprintf(format, arg...)						\
59 	printf("%s:(%s)" format, __func__, clknode_get_name(clk), arg)
60 #else
61 #define	dprintf(format, arg...)
62 #endif
63 
64 static int rk_clk_mux_init(struct clknode *clk, device_t dev);
65 static int rk_clk_mux_set_mux(struct clknode *clk, int idx);
66 static int rk_clk_mux_set_freq(struct clknode *clk, uint64_t fparent,
67     uint64_t *fout, int flags, int *stop);
68 
69 struct rk_clk_mux_sc {
70 	uint32_t	offset;
71 	uint32_t	shift;
72 	uint32_t	mask;
73 	int		mux_flags;
74 	struct syscon	*grf;
75 };
76 
77 static clknode_method_t rk_clk_mux_methods[] = {
78 	/* Device interface */
79 	CLKNODEMETHOD(clknode_init, 	rk_clk_mux_init),
80 	CLKNODEMETHOD(clknode_set_mux, 	rk_clk_mux_set_mux),
81 	CLKNODEMETHOD(clknode_set_freq,	rk_clk_mux_set_freq),
82 	CLKNODEMETHOD_END
83 };
84 DEFINE_CLASS_1(rk_clk_mux, rk_clk_mux_class, rk_clk_mux_methods,
85    sizeof(struct rk_clk_mux_sc), clknode_class);
86 
87 static struct syscon *
88 rk_clk_mux_get_grf(struct clknode *clk)
89 {
90 	device_t dev;
91 	phandle_t node;
92 	struct syscon *grf;
93 
94 	grf = NULL;
95 	dev = clknode_get_device(clk);
96 	node = ofw_bus_get_node(dev);
97 	if (OF_hasprop(node, "rockchip,grf") &&
98 	    syscon_get_by_ofw_property(dev, node,
99 	    "rockchip,grf", &grf) != 0) {
100 		return (NULL);
101 	}
102 
103 	return (grf);
104 }
105 
106 static int
107 rk_clk_mux_init(struct clknode *clk, device_t dev)
108 {
109 	uint32_t reg;
110 	struct rk_clk_mux_sc *sc;
111 	int rv;
112 
113 	sc = clknode_get_softc(clk);
114 
115 	if ((sc->mux_flags & RK_CLK_MUX_GRF) != 0) {
116 		sc->grf = rk_clk_mux_get_grf(clk);
117 		if (sc->grf == NULL)
118 			panic("clock %s has GRF flag set but no syscon is available",
119 			    clknode_get_name(clk));
120 	}
121 
122 	DEVICE_LOCK(clk);
123 	if (sc->grf) {
124 		reg = SYSCON_READ_4(sc->grf, sc->offset);
125 		rv = 0;
126 	} else
127 		rv = RD4(clk, sc->offset, &reg);
128 	DEVICE_UNLOCK(clk);
129 	if (rv != 0) {
130 		return (rv);
131 	}
132 	reg = (reg >> sc->shift) & sc->mask;
133 	clknode_init_parent_idx(clk, reg);
134 	return(0);
135 }
136 
137 static int
138 rk_clk_mux_set_mux(struct clknode *clk, int idx)
139 {
140 	uint32_t reg;
141 	struct rk_clk_mux_sc *sc;
142 	int rv;
143 
144 	sc = clknode_get_softc(clk);
145 
146 	DEVICE_LOCK(clk);
147 	if (sc->grf)
148 		rv = SYSCON_MODIFY_4(sc->grf, sc->offset, sc->mask << sc->shift,
149 		  ((idx & sc->mask) << sc->shift) | RK_CLK_MUX_MASK);
150 	else
151 		rv = MD4(clk, sc->offset, sc->mask << sc->shift,
152 		  ((idx & sc->mask) << sc->shift) | RK_CLK_MUX_MASK);
153 	if (rv != 0) {
154 		DEVICE_UNLOCK(clk);
155 		return (rv);
156 	}
157 	if (sc->grf == NULL)
158 		RD4(clk, sc->offset, &reg);
159 	DEVICE_UNLOCK(clk);
160 
161 	return(0);
162 }
163 
164 static int
165 rk_clk_mux_set_freq(struct clknode *clk, uint64_t fparent, uint64_t *fout,
166     int flags, int *stop)
167 {
168 	struct rk_clk_mux_sc *sc;
169 	struct clknode *p_clk, *p_best_clk;
170 	const char **p_names;
171 	int p_idx, best_parent;
172 	int rv;
173 
174 	sc = clknode_get_softc(clk);
175 
176 	if ((sc->mux_flags & RK_CLK_MUX_GRF) != 0) {
177 		*stop = 1;
178 		return (ENOTSUP);
179 	}
180 	if ((sc->mux_flags & RK_CLK_MUX_REPARENT) == 0) {
181 		*stop = 0;
182 		return (0);
183 	}
184 
185 	dprintf("Finding best parent for target freq of %ju\n", *fout);
186 	p_names = clknode_get_parent_names(clk);
187 	for (p_idx = 0; p_idx != clknode_get_parents_num(clk); p_idx++) {
188 		p_clk = clknode_find_by_name(p_names[p_idx]);
189 		dprintf("Testing with parent %s (%d)\n",
190 		    clknode_get_name(p_clk), p_idx);
191 
192 		rv = clknode_set_freq(p_clk, *fout, flags | CLK_SET_DRYRUN, 0);
193 		dprintf("Testing with parent %s (%d) rv=%d\n",
194 		    clknode_get_name(p_clk), p_idx, rv);
195 		if (rv == 0) {
196 			best_parent = p_idx;
197 			p_best_clk = p_clk;
198 			*stop = 1;
199 		}
200 	}
201 
202 	if (!*stop)
203 		return (0);
204 
205 	if ((flags & CLK_SET_DRYRUN) != 0)
206 		return (0);
207 
208 	p_idx = clknode_get_parent_idx(clk);
209 	if (p_idx != best_parent) {
210 		dprintf("Switching parent index from %d to %d\n", p_idx,
211 		    best_parent);
212 		clknode_set_parent_by_idx(clk, best_parent);
213 	}
214 
215 	clknode_set_freq(p_best_clk, *fout, flags, 0);
216 	clknode_get_freq(p_best_clk, fout);
217 
218 	return (0);
219 }
220 
221 int
222 rk_clk_mux_register(struct clkdom *clkdom, struct rk_clk_mux_def *clkdef)
223 {
224 	struct clknode *clk;
225 	struct rk_clk_mux_sc *sc;
226 
227 	clk = clknode_create(clkdom, &rk_clk_mux_class, &clkdef->clkdef);
228 	if (clk == NULL)
229 		return (1);
230 
231 	sc = clknode_get_softc(clk);
232 	sc->offset = clkdef->offset;
233 	sc->shift = clkdef->shift;
234 	sc->mask =  (1 << clkdef->width) - 1;
235 	sc->mux_flags = clkdef->mux_flags;
236 
237 	clknode_register(clkdom, clk);
238 	return (0);
239 }
240