xref: /openbmc/linux/arch/mips/generic/init.c (revision fa7f32422ea1ac276b45b96a540ed5981caaa61f)
1 /*
2  * Copyright (C) 2016 Imagination Technologies
3  * Author: Paul Burton <paul.burton@imgtec.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License as published by the
7  * Free Software Foundation;  either version 2 of the  License, or (at your
8  * option) any later version.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/clk-provider.h>
13 #include <linux/clocksource.h>
14 #include <linux/init.h>
15 #include <linux/irqchip.h>
16 #include <linux/of_fdt.h>
17 #include <linux/of_platform.h>
18 
19 #include <asm/fw/fw.h>
20 #include <asm/irq_cpu.h>
21 #include <asm/machine.h>
22 #include <asm/mips-cpc.h>
23 #include <asm/prom.h>
24 #include <asm/smp-ops.h>
25 #include <asm/time.h>
26 
27 static __initdata const void *fdt;
28 static __initdata const struct mips_machine *mach;
29 static __initdata const void *mach_match_data;
30 
31 void __init prom_init(void)
32 {
33 	const struct mips_machine *check_mach;
34 	const struct of_device_id *match;
35 
36 	if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
37 		/*
38 		 * We booted using the UHI boot protocol, so we have been
39 		 * provided with the appropriate device tree for the board.
40 		 * Make use of it & search for any machine struct based upon
41 		 * the root compatible string.
42 		 */
43 		fdt = (void *)fw_arg1;
44 
45 		for_each_mips_machine(check_mach) {
46 			match = mips_machine_is_compatible(check_mach, fdt);
47 			if (match) {
48 				mach = check_mach;
49 				mach_match_data = match->data;
50 				break;
51 			}
52 		}
53 	} else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
54 		/*
55 		 * We weren't booted using the UHI boot protocol, but do
56 		 * support some number of boards with legacy boot protocols.
57 		 * Attempt to find the right one.
58 		 */
59 		for_each_mips_machine(check_mach) {
60 			if (!check_mach->detect)
61 				continue;
62 
63 			if (!check_mach->detect())
64 				continue;
65 
66 			mach = check_mach;
67 		}
68 
69 		/*
70 		 * If we don't recognise the machine then we can't continue, so
71 		 * die here.
72 		 */
73 		BUG_ON(!mach);
74 
75 		/* Retrieve the machine's FDT */
76 		fdt = mach->fdt;
77 	}
78 
79 	BUG_ON(!fdt);
80 }
81 
82 void __init *plat_get_fdt(void)
83 {
84 	return (void *)fdt;
85 }
86 
87 void __init plat_mem_setup(void)
88 {
89 	if (mach && mach->fixup_fdt)
90 		fdt = mach->fixup_fdt(fdt, mach_match_data);
91 
92 	strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
93 	__dt_setup_arch((void *)fdt);
94 }
95 
96 void __init device_tree_init(void)
97 {
98 	int err;
99 
100 	unflatten_and_copy_device_tree();
101 	mips_cpc_probe();
102 
103 	err = register_cps_smp_ops();
104 	if (err)
105 		err = register_up_smp_ops();
106 }
107 
108 void __init plat_time_init(void)
109 {
110 	struct device_node *np;
111 	struct clk *clk;
112 
113 	of_clk_init(NULL);
114 
115 	if (!cpu_has_counter) {
116 		mips_hpt_frequency = 0;
117 	} else if (mach && mach->measure_hpt_freq) {
118 		mips_hpt_frequency = mach->measure_hpt_freq();
119 	} else {
120 		np = of_get_cpu_node(0, NULL);
121 		if (!np) {
122 			pr_err("Failed to get CPU node\n");
123 			return;
124 		}
125 
126 		clk = of_clk_get(np, 0);
127 		if (IS_ERR(clk)) {
128 			pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
129 			return;
130 		}
131 
132 		mips_hpt_frequency = clk_get_rate(clk);
133 		clk_put(clk);
134 
135 		switch (boot_cpu_type()) {
136 		case CPU_20KC:
137 		case CPU_25KF:
138 			/* The counter runs at the CPU clock rate */
139 			break;
140 		default:
141 			/* The counter runs at half the CPU clock rate */
142 			mips_hpt_frequency /= 2;
143 			break;
144 		}
145 	}
146 
147 	clocksource_probe();
148 }
149 
150 void __init arch_init_irq(void)
151 {
152 	struct device_node *intc_node;
153 
154 	intc_node = of_find_compatible_node(NULL, NULL,
155 					    "mti,cpu-interrupt-controller");
156 	if (!cpu_has_veic && !intc_node)
157 		mips_cpu_irq_init();
158 
159 	irqchip_init();
160 }
161 
162 static int __init publish_devices(void)
163 {
164 	if (!of_have_populated_dt())
165 		panic("Device-tree not present");
166 
167 	if (of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL))
168 		panic("Failed to populate DT");
169 
170 	return 0;
171 }
172 arch_initcall(publish_devices);
173 
174 void __init prom_free_prom_memory(void)
175 {
176 }
177