xref: /freebsd/sys/riscv/starfive/starfive_syscon.c (revision 5d6d6278979b9eab598a23c804d23e930d2f7268)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2024 The FreeBSD Foundation
5  *
6  * This software was developed by Mitchell Horne <mhorne@FreeBSD.org> under
7  * sponsorship from the FreeBSD Foundation.
8  */
9 
10 /*
11  * StarFive syscon driver.
12  *
13  * On the JH7110, the PLL clock driver is a child of the sys-syscon device.
14  * This needs to probe very early (BUS_PASS_BUS + BUS_PASS_ORDER_EARLY).
15  */
16 
17 #include <sys/param.h>
18 #include <sys/bus.h>
19 #include <sys/kernel.h>
20 #include <sys/module.h>
21 #include <sys/mutex.h>
22 
23 #include <machine/bus.h>
24 
25 #include <dev/ofw/openfirm.h>
26 #include <dev/ofw/ofw_bus.h>
27 #include <dev/ofw/ofw_bus_subr.h>
28 
29 #include <dev/syscon/syscon.h>
30 #include <dev/syscon/syscon_generic.h>
31 
32 #include <dev/fdt/simple_mfd.h>
33 
34 enum starfive_syscon_type {
35 	JH7110_SYSCON_SYS = 1,
36 	JH7110_SYSCON_AON,
37 	JH7110_SYSCON_STG,
38 };
39 
40 static struct ofw_compat_data compat_data[] = {
41 	{ "starfive,jh7110-sys-syscon",	JH7110_SYSCON_SYS },
42 	{ "starfive,jh7110-aon-syscon",	JH7110_SYSCON_AON },
43 	{ "starfive,jh7110-stg-syscon",	JH7110_SYSCON_STG },
44 
45 	{ NULL, 0 }
46 };
47 
48 static int
49 starfive_syscon_probe(device_t dev)
50 {
51 	enum starfive_syscon_type type;
52 
53 	if (!ofw_bus_status_okay(dev))
54 		return (ENXIO);
55 
56 	type = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
57 	if (type == 0)
58 		return (ENXIO);
59 
60 	switch (type) {
61 	case JH7110_SYSCON_SYS:
62 		device_set_desc(dev, "JH7110 SYS syscon");
63 		break;
64 	case JH7110_SYSCON_AON:
65 		device_set_desc(dev, "JH7110 AON syscon");
66 		break;
67 	case JH7110_SYSCON_STG:
68 		device_set_desc(dev, "JH7110 STG syscon");
69 		break;
70 	}
71 
72 	return (BUS_PROBE_DEFAULT);
73 }
74 
75 
76 static device_method_t starfive_syscon_methods[] = {
77 	DEVMETHOD(device_probe, starfive_syscon_probe),
78 
79 	DEVMETHOD_END
80 };
81 
82 DEFINE_CLASS_1(starfive_syscon, starfive_syscon_driver, starfive_syscon_methods,
83     sizeof(struct syscon_generic_softc), simple_mfd_driver);
84 
85 EARLY_DRIVER_MODULE(starfive_syscon, simplebus, starfive_syscon_driver, 0, 0,
86     BUS_PASS_BUS + BUS_PASS_ORDER_EARLY);
87 MODULE_VERSION(starfive_syscon, 1);
88