xref: /openbmc/linux/arch/mips/generic/init.c (revision 423997ff)
1 /*
2  * Copyright (C) 2016 Imagination Technologies
3  * Author: Paul Burton <paul.burton@mips.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 
18 #include <asm/bootinfo.h>
19 #include <asm/fw/fw.h>
20 #include <asm/irq_cpu.h>
21 #include <asm/machine.h>
22 #include <asm/mips-cps.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 	plat_get_fdt();
34 	BUG_ON(!fdt);
35 }
36 
37 void __init *plat_get_fdt(void)
38 {
39 	const struct mips_machine *check_mach;
40 	const struct of_device_id *match;
41 
42 	if (fdt)
43 		/* Already set up */
44 		return (void *)fdt;
45 
46 	if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_passed_dtb)) {
47 		/*
48 		 * We booted using the UHI boot protocol, so we have been
49 		 * provided with the appropriate device tree for the board.
50 		 * Make use of it & search for any machine struct based upon
51 		 * the root compatible string.
52 		 */
53 		fdt = (void *)fw_passed_dtb;
54 
55 		for_each_mips_machine(check_mach) {
56 			match = mips_machine_is_compatible(check_mach, fdt);
57 			if (match) {
58 				mach = check_mach;
59 				mach_match_data = match->data;
60 				break;
61 			}
62 		}
63 	} else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
64 		/*
65 		 * We weren't booted using the UHI boot protocol, but do
66 		 * support some number of boards with legacy boot protocols.
67 		 * Attempt to find the right one.
68 		 */
69 		for_each_mips_machine(check_mach) {
70 			if (!check_mach->detect)
71 				continue;
72 
73 			if (!check_mach->detect())
74 				continue;
75 
76 			mach = check_mach;
77 		}
78 
79 		/*
80 		 * If we don't recognise the machine then we can't continue, so
81 		 * die here.
82 		 */
83 		BUG_ON(!mach);
84 
85 		/* Retrieve the machine's FDT */
86 		fdt = mach->fdt;
87 	}
88 	return (void *)fdt;
89 }
90 
91 #ifdef CONFIG_RELOCATABLE
92 
93 void __init plat_fdt_relocated(void *new_location)
94 {
95 	/*
96 	 * reset fdt as the cached value would point to the location
97 	 * before relocations happened and update the location argument
98 	 * if it was passed using UHI
99 	 */
100 	fdt = NULL;
101 
102 	if (fw_arg0 == -2)
103 		fw_arg1 = (unsigned long)new_location;
104 }
105 
106 #endif /* CONFIG_RELOCATABLE */
107 
108 void __init plat_mem_setup(void)
109 {
110 	if (mach && mach->fixup_fdt)
111 		fdt = mach->fixup_fdt(fdt, mach_match_data);
112 
113 	strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
114 	__dt_setup_arch((void *)fdt);
115 }
116 
117 void __init device_tree_init(void)
118 {
119 	int err;
120 
121 	unflatten_and_copy_device_tree();
122 	mips_cpc_probe();
123 
124 	err = register_cps_smp_ops();
125 	if (err)
126 		err = register_up_smp_ops();
127 }
128 
129 int __init apply_mips_fdt_fixups(void *fdt_out, size_t fdt_out_size,
130 				 const void *fdt_in,
131 				 const struct mips_fdt_fixup *fixups)
132 {
133 	int err;
134 
135 	err = fdt_open_into(fdt_in, fdt_out, fdt_out_size);
136 	if (err) {
137 		pr_err("Failed to open FDT\n");
138 		return err;
139 	}
140 
141 	for (; fixups->apply; fixups++) {
142 		err = fixups->apply(fdt_out);
143 		if (err) {
144 			pr_err("Failed to apply FDT fixup \"%s\"\n",
145 			       fixups->description);
146 			return err;
147 		}
148 	}
149 
150 	err = fdt_pack(fdt_out);
151 	if (err)
152 		pr_err("Failed to pack FDT\n");
153 	return err;
154 }
155 
156 void __init plat_time_init(void)
157 {
158 	struct device_node *np;
159 	struct clk *clk;
160 
161 	of_clk_init(NULL);
162 
163 	if (!cpu_has_counter) {
164 		mips_hpt_frequency = 0;
165 	} else if (mach && mach->measure_hpt_freq) {
166 		mips_hpt_frequency = mach->measure_hpt_freq();
167 	} else {
168 		np = of_get_cpu_node(0, NULL);
169 		if (!np) {
170 			pr_err("Failed to get CPU node\n");
171 			return;
172 		}
173 
174 		clk = of_clk_get(np, 0);
175 		if (IS_ERR(clk)) {
176 			pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
177 			return;
178 		}
179 
180 		mips_hpt_frequency = clk_get_rate(clk);
181 		clk_put(clk);
182 
183 		switch (boot_cpu_type()) {
184 		case CPU_20KC:
185 		case CPU_25KF:
186 			/* The counter runs at the CPU clock rate */
187 			break;
188 		default:
189 			/* The counter runs at half the CPU clock rate */
190 			mips_hpt_frequency /= 2;
191 			break;
192 		}
193 	}
194 
195 	timer_probe();
196 }
197 
198 void __init arch_init_irq(void)
199 {
200 	struct device_node *intc_node;
201 
202 	intc_node = of_find_compatible_node(NULL, NULL,
203 					    "mti,cpu-interrupt-controller");
204 	if (!cpu_has_veic && !intc_node)
205 		mips_cpu_irq_init();
206 	of_node_put(intc_node);
207 
208 	irqchip_init();
209 }
210 
211 void __init prom_free_prom_memory(void)
212 {
213 }
214