xref: /openbmc/linux/arch/mips/generic/init.c (revision 835fd614)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2016 Imagination Technologies
4  * Author: Paul Burton <paul.burton@mips.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/clocksource.h>
9 #include <linux/init.h>
10 #include <linux/irqchip.h>
11 #include <linux/of_clk.h>
12 #include <linux/of_fdt.h>
13 
14 #include <asm/bootinfo.h>
15 #include <asm/fw/fw.h>
16 #include <asm/irq_cpu.h>
17 #include <asm/machine.h>
18 #include <asm/mips-cps.h>
19 #include <asm/prom.h>
20 #include <asm/smp-ops.h>
21 #include <asm/time.h>
22 
23 static __initconst const void *fdt;
24 static __initconst const struct mips_machine *mach;
25 static __initconst const void *mach_match_data;
26 
27 void __init prom_init(void)
28 {
29 	plat_get_fdt();
30 	BUG_ON(!fdt);
31 }
32 
33 void __init *plat_get_fdt(void)
34 {
35 	const struct mips_machine *check_mach;
36 	const struct of_device_id *match;
37 
38 	if (fdt)
39 		/* Already set up */
40 		return (void *)fdt;
41 
42 	if (fw_passed_dtb && !fdt_check_header((void *)fw_passed_dtb)) {
43 		/*
44 		 * We have been provided with the appropriate device tree for
45 		 * the board. Make use of it & search for any machine struct
46 		 * based upon the root compatible string.
47 		 */
48 		fdt = (void *)fw_passed_dtb;
49 
50 		for_each_mips_machine(check_mach) {
51 			match = mips_machine_is_compatible(check_mach, fdt);
52 			if (match) {
53 				mach = check_mach;
54 				mach_match_data = match->data;
55 				break;
56 			}
57 		}
58 	} else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
59 		/*
60 		 * We weren't booted using the UHI boot protocol, but do
61 		 * support some number of boards with legacy boot protocols.
62 		 * Attempt to find the right one.
63 		 */
64 		for_each_mips_machine(check_mach) {
65 			if (!check_mach->detect)
66 				continue;
67 
68 			if (!check_mach->detect())
69 				continue;
70 
71 			mach = check_mach;
72 		}
73 
74 		/*
75 		 * If we don't recognise the machine then we can't continue, so
76 		 * die here.
77 		 */
78 		BUG_ON(!mach);
79 
80 		/* Retrieve the machine's FDT */
81 		fdt = mach->fdt;
82 	}
83 	return (void *)fdt;
84 }
85 
86 #ifdef CONFIG_RELOCATABLE
87 
88 void __init plat_fdt_relocated(void *new_location)
89 {
90 	/*
91 	 * reset fdt as the cached value would point to the location
92 	 * before relocations happened and update the location argument
93 	 * if it was passed using UHI
94 	 */
95 	fdt = NULL;
96 
97 	if (fw_arg0 == -2)
98 		fw_arg1 = (unsigned long)new_location;
99 }
100 
101 #endif /* CONFIG_RELOCATABLE */
102 
103 void __init plat_mem_setup(void)
104 {
105 	if (mach && mach->fixup_fdt)
106 		fdt = mach->fixup_fdt(fdt, mach_match_data);
107 
108 	fw_init_cmdline();
109 	__dt_setup_arch((void *)fdt);
110 }
111 
112 void __init device_tree_init(void)
113 {
114 	int err;
115 
116 	unflatten_and_copy_device_tree();
117 	mips_cpc_probe();
118 
119 	err = register_cps_smp_ops();
120 	if (err)
121 		err = register_up_smp_ops();
122 }
123 
124 int __init apply_mips_fdt_fixups(void *fdt_out, size_t fdt_out_size,
125 				 const void *fdt_in,
126 				 const struct mips_fdt_fixup *fixups)
127 {
128 	int err;
129 
130 	err = fdt_open_into(fdt_in, fdt_out, fdt_out_size);
131 	if (err) {
132 		pr_err("Failed to open FDT\n");
133 		return err;
134 	}
135 
136 	for (; fixups->apply; fixups++) {
137 		err = fixups->apply(fdt_out);
138 		if (err) {
139 			pr_err("Failed to apply FDT fixup \"%s\"\n",
140 			       fixups->description);
141 			return err;
142 		}
143 	}
144 
145 	err = fdt_pack(fdt_out);
146 	if (err)
147 		pr_err("Failed to pack FDT\n");
148 	return err;
149 }
150 
151 void __init plat_time_init(void)
152 {
153 	struct device_node *np;
154 	struct clk *clk;
155 
156 	of_clk_init(NULL);
157 
158 	if (!cpu_has_counter) {
159 		mips_hpt_frequency = 0;
160 	} else if (mach && mach->measure_hpt_freq) {
161 		mips_hpt_frequency = mach->measure_hpt_freq();
162 	} else {
163 		np = of_get_cpu_node(0, NULL);
164 		if (!np) {
165 			pr_err("Failed to get CPU node\n");
166 			return;
167 		}
168 
169 		clk = of_clk_get(np, 0);
170 		if (IS_ERR(clk)) {
171 			pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
172 			return;
173 		}
174 
175 		mips_hpt_frequency = clk_get_rate(clk);
176 		clk_put(clk);
177 
178 		switch (boot_cpu_type()) {
179 		case CPU_20KC:
180 		case CPU_25KF:
181 			/* The counter runs at the CPU clock rate */
182 			break;
183 		default:
184 			/* The counter runs at half the CPU clock rate */
185 			mips_hpt_frequency /= 2;
186 			break;
187 		}
188 	}
189 
190 	timer_probe();
191 }
192 
193 void __init arch_init_irq(void)
194 {
195 	struct device_node *intc_node;
196 
197 	intc_node = of_find_compatible_node(NULL, NULL,
198 					    "mti,cpu-interrupt-controller");
199 	if (!cpu_has_veic && !intc_node)
200 		mips_cpu_irq_init();
201 	of_node_put(intc_node);
202 
203 	irqchip_init();
204 }
205 
206 void __init prom_free_prom_memory(void)
207 {
208 }
209