ti_cpufreq.c revision 1.4 
1/* $NetBSD: ti_cpufreq.c,v 1.4 2021/01/27 03:10:20 thorpej Exp $ */
2
3/*-
4 * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
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 ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * 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 "opt_soc.h"
30
31#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD: ti_cpufreq.c,v 1.4 2021/01/27 03:10:20 thorpej Exp $");
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/device.h>
37#include <sys/kmem.h>
38#include <sys/bus.h>
39
40#include <dev/fdt/fdtvar.h>
41#include <dev/fdt/syscon.h>
42
43static bool		ti_opp_probed = false;
44static bool		(*ti_opp_supportedfn)(const int, const int);
45static struct syscon	*ti_opp_syscon;
46
47#ifdef SOC_AM33XX
48
49#define	AM33XX_REV_OFFSET	0x0600
50#define	AM33XX_REV_MASK		0xf0000000
51#define	AM33XX_EFUSE_OFFSET	0x07fc
52#define	AM33XX_EFUSE_MASK	0x00001fff
53#define	AM33XX_EFUSE_DEFAULT	0x1e2f
54
55static const struct device_compatible_entry am33xx_compat_data[] = {
56	{ .compat = "ti,am33xx" },
57	DEVICE_COMPAT_EOL
58};
59
60static bool
61am33xx_opp_supported(const int opp_table, const int opp_node)
62{
63	const u_int *supported_hw;
64	uint32_t efuse, rev;
65	int len;
66
67	syscon_lock(ti_opp_syscon);
68	rev = __BIT(__SHIFTOUT(syscon_read_4(ti_opp_syscon, AM33XX_REV_OFFSET), AM33XX_REV_MASK));
69	efuse = __SHIFTOUT(syscon_read_4(ti_opp_syscon, AM33XX_EFUSE_OFFSET), AM33XX_EFUSE_MASK);
70	syscon_unlock(ti_opp_syscon);
71
72	if (efuse == 0)
73		efuse = AM33XX_EFUSE_DEFAULT;
74	efuse = ~efuse;
75
76	supported_hw = fdtbus_get_prop(opp_node, "opp-supported-hw", &len);
77	if (len != 8)
78		return false;
79
80	if ((rev & be32toh(supported_hw[0])) == 0)
81		return false;
82
83	if ((efuse & be32toh(supported_hw[1])) == 0)
84		return false;
85
86	return true;
87}
88#endif
89
90static void
91ti_opp_probe(const int opp_table)
92{
93	if (ti_opp_probed)
94		return;
95	ti_opp_probed = true;
96
97	ti_opp_syscon = fdtbus_syscon_acquire(opp_table, "syscon");
98
99#ifdef SOC_AM33XX
100	if (ti_opp_syscon &&
101	    of_compatible_match(OF_finddevice("/"), am33xx_compat_data))
102		ti_opp_supportedfn = am33xx_opp_supported;
103#endif
104}
105
106static bool
107ti_opp_supported(const int opp_table, const int opp_node)
108{
109	ti_opp_probe(opp_table);
110
111	if (!of_hasprop(opp_node, "opp-supported-hw"))
112		return true;
113
114	return ti_opp_supportedfn ? ti_opp_supportedfn(opp_table, opp_node) : false;
115}
116
117FDT_OPP(ti, "operating-points-v2-ti-cpu", ti_opp_supported);
118