xref: /netbsd-src/sys/arch/powerpc/oea/cpu_speedctl.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: cpu_speedctl.c,v 1.1 2018/06/01 18:06:58 macallan Exp $ */
2 
3 /*-
4  * Copyright (c) 2006 Michael Lorenz
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: cpu_speedctl.c,v 1.1 2018/06/01 18:06:58 macallan Exp $");
30 
31 #include "opt_ppcparam.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/device.h>
36 #include <sys/types.h>
37 
38 #include <powerpc/psl.h>
39 #include <powerpc/spr.h>
40 #include <powerpc/oea/cpufeat.h>
41 #include <powerpc/oea/spr.h>
42 
43 #include <sys/sysctl.h>
44 #include <dev/ofw/openfirm.h>
45 
46 void init_scom_speedctl(void);
47 static int scom_speedctl = 0;
48 static uint32_t scom_speeds[2];
49 static uint32_t scom_reg[2];
50 static int  sysctl_cpuspeed_temp(SYSCTLFN_ARGS);
51 static int  sysctl_cpuspeed_cur(SYSCTLFN_ARGS);
52 static int  sysctl_cpuspeed_available(SYSCTLFN_ARGS);
53 
54 void
55 init_scom_speedctl(void)
56 {
57 	int node;
58 	const struct sysctlnode *sysctl_node, *me, *freq;
59 
60 	/* do this only once */
61 	if (scom_speedctl != 0) return;
62 	scom_speedctl = 1;
63 
64 	node = OF_finddevice("/cpus/@0");
65 	if (OF_getprop(node, "power-mode-data", scom_reg, 8) != 8)
66 		return;
67 	if (OF_getprop(node, "clock-frequency", scom_speeds, 4) != 4)
68 		return;
69 	scom_speeds[0] = scom_speeds[0] / 1000000; /* Hz -> MHz */
70 	scom_speeds[1] = scom_speeds[0] / 2;
71 
72 	sysctl_node = NULL;
73 
74 	if (sysctl_createv(NULL, 0, NULL,
75 	    &me,
76 	    CTLFLAG_READWRITE, CTLTYPE_NODE, "cpu", NULL, NULL,
77 	    0, NULL, 0, CTL_MACHDEP, CTL_CREATE, CTL_EOL) != 0)
78 		printf("couldn't create 'cpu' node\n");
79 
80 	if (sysctl_createv(NULL, 0, NULL,
81 	    &freq,
82 	    CTLFLAG_READWRITE, CTLTYPE_NODE, "frequency", NULL, NULL,
83 	    0, NULL, 0, CTL_MACHDEP, me->sysctl_num, CTL_CREATE, CTL_EOL) != 0)
84 		printf("couldn't create 'frequency' node\n");
85 
86 	if (sysctl_createv(NULL, 0, NULL,
87 	    &sysctl_node,
88 	    CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
89 	    CTLTYPE_INT, "target", "CPU speed", sysctl_cpuspeed_temp,
90 	    0, NULL, 0, CTL_MACHDEP, me->sysctl_num, freq->sysctl_num,
91 	    CTL_CREATE, CTL_EOL) == 0) {
92 	} else
93 		printf("couldn't create 'target' node\n");
94 
95 	if (sysctl_createv(NULL, 0, NULL,
96 	    &sysctl_node,
97 	    CTLFLAG_READWRITE,
98 	    CTLTYPE_INT, "current", NULL, sysctl_cpuspeed_cur,
99 	    1, NULL, 0, CTL_MACHDEP, me->sysctl_num, freq->sysctl_num,
100 	    CTL_CREATE, CTL_EOL) == 0) {
101 	} else
102 		printf("couldn't create 'current' node\n");
103 
104 	if (sysctl_createv(NULL, 0, NULL,
105 	    &sysctl_node,
106 	    CTLFLAG_READWRITE,
107 	    CTLTYPE_STRING, "available", NULL, sysctl_cpuspeed_available,
108 	    2, NULL, 0, CTL_MACHDEP, me->sysctl_num, freq->sysctl_num,
109 	    CTL_CREATE, CTL_EOL) == 0) {
110 	} else
111 		printf("couldn't create 'available' node\n");
112 }
113 
114 static int
115 sysctl_cpuspeed_temp(SYSCTLFN_ARGS)
116 {
117 	struct sysctlnode node = *rnode;
118 	int speed, nspeed = -1, mhz;
119 
120 	speed = (scom_read(SCOM_PSR) >> 56) & 3;
121 	if (speed > 1) speed = 1;
122 	mhz = scom_speeds[speed];
123 	node.sysctl_data = &mhz;
124 
125 	if (sysctl_lookup(SYSCTLFN_CALL(&node)) == 0) {
126 		int new_reg;
127 
128 		new_reg = *(int *)node.sysctl_data;
129 		if (new_reg == scom_speeds[0]) {
130 			nspeed = 0;
131 		} else if (new_reg == scom_speeds[1]) {
132 			nspeed = 1;
133 		} else {
134 			printf("%s: new_reg %d\n", __func__, new_reg);
135 			return EINVAL;
136 		}
137 		if (nspeed != speed) {
138 			volatile uint64_t junk;
139 			scom_write(SCOM_PCR, 0x80000000);
140 			scom_write(SCOM_PCR, scom_reg[nspeed]);
141 			junk = scom_read(SCOM_PSR);
142 			__USE(junk);
143 		}
144 		return 0;
145 	}
146 	return EINVAL;
147 }
148 
149 static int
150 sysctl_cpuspeed_cur(SYSCTLFN_ARGS)
151 {
152 	struct sysctlnode node = *rnode;
153 	uint64_t speed;
154 	int mhz;
155 
156 	speed = (scom_read(SCOM_PSR) >> 56) & 3;
157 	if (speed > 1) speed = 1;
158 
159 	mhz = scom_speeds[speed];
160 	node.sysctl_data = &mhz;
161 	return sysctl_lookup(SYSCTLFN_CALL(&node));
162 }
163 
164 static int
165 sysctl_cpuspeed_available(SYSCTLFN_ARGS)
166 {
167 	struct sysctlnode node = *rnode;
168 	char buf[128];
169 
170 	snprintf(buf, 128, "%d %d", scom_speeds[0], scom_speeds[1]);
171 	node.sysctl_data = buf;
172 	return(sysctl_lookup(SYSCTLFN_CALL(&node)));
173 }
174 
175 SYSCTL_SETUP(sysctl_ams_setup, "sysctl obio subtree setup")
176 {
177 
178 	sysctl_createv(NULL, 0, NULL, NULL,
179 		       CTLFLAG_PERMANENT,
180 		       CTLTYPE_NODE, "machdep", NULL,
181 		       NULL, 0, NULL, 0,
182 		       CTL_MACHDEP, CTL_EOL);
183 }
184