xref: /openbmc/linux/arch/mips/generic/init.c (revision 20e2fc42)
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/clk-provider.h>
9 #include <linux/clocksource.h>
10 #include <linux/init.h>
11 #include <linux/irqchip.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 __initdata const void *fdt;
24 static __initdata const struct mips_machine *mach;
25 static __initdata 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_arg0 == -2) && !fdt_check_header((void *)fw_passed_dtb)) {
43 		/*
44 		 * We booted using the UHI boot protocol, so we have been
45 		 * provided with the appropriate device tree for the board.
46 		 * Make use of it & search for any machine struct based upon
47 		 * the root compatible string.
48 		 */
49 		fdt = (void *)fw_passed_dtb;
50 
51 		for_each_mips_machine(check_mach) {
52 			match = mips_machine_is_compatible(check_mach, fdt);
53 			if (match) {
54 				mach = check_mach;
55 				mach_match_data = match->data;
56 				break;
57 			}
58 		}
59 	} else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
60 		/*
61 		 * We weren't booted using the UHI boot protocol, but do
62 		 * support some number of boards with legacy boot protocols.
63 		 * Attempt to find the right one.
64 		 */
65 		for_each_mips_machine(check_mach) {
66 			if (!check_mach->detect)
67 				continue;
68 
69 			if (!check_mach->detect())
70 				continue;
71 
72 			mach = check_mach;
73 		}
74 
75 		/*
76 		 * If we don't recognise the machine then we can't continue, so
77 		 * die here.
78 		 */
79 		BUG_ON(!mach);
80 
81 		/* Retrieve the machine's FDT */
82 		fdt = mach->fdt;
83 	}
84 	return (void *)fdt;
85 }
86 
87 #ifdef CONFIG_RELOCATABLE
88 
89 void __init plat_fdt_relocated(void *new_location)
90 {
91 	/*
92 	 * reset fdt as the cached value would point to the location
93 	 * before relocations happened and update the location argument
94 	 * if it was passed using UHI
95 	 */
96 	fdt = NULL;
97 
98 	if (fw_arg0 == -2)
99 		fw_arg1 = (unsigned long)new_location;
100 }
101 
102 #endif /* CONFIG_RELOCATABLE */
103 
104 void __init plat_mem_setup(void)
105 {
106 	if (mach && mach->fixup_fdt)
107 		fdt = mach->fixup_fdt(fdt, mach_match_data);
108 
109 	strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
110 	__dt_setup_arch((void *)fdt);
111 }
112 
113 void __init device_tree_init(void)
114 {
115 	int err;
116 
117 	unflatten_and_copy_device_tree();
118 	mips_cpc_probe();
119 
120 	err = register_cps_smp_ops();
121 	if (err)
122 		err = register_up_smp_ops();
123 }
124 
125 int __init apply_mips_fdt_fixups(void *fdt_out, size_t fdt_out_size,
126 				 const void *fdt_in,
127 				 const struct mips_fdt_fixup *fixups)
128 {
129 	int err;
130 
131 	err = fdt_open_into(fdt_in, fdt_out, fdt_out_size);
132 	if (err) {
133 		pr_err("Failed to open FDT\n");
134 		return err;
135 	}
136 
137 	for (; fixups->apply; fixups++) {
138 		err = fixups->apply(fdt_out);
139 		if (err) {
140 			pr_err("Failed to apply FDT fixup \"%s\"\n",
141 			       fixups->description);
142 			return err;
143 		}
144 	}
145 
146 	err = fdt_pack(fdt_out);
147 	if (err)
148 		pr_err("Failed to pack FDT\n");
149 	return err;
150 }
151 
152 void __init plat_time_init(void)
153 {
154 	struct device_node *np;
155 	struct clk *clk;
156 
157 	of_clk_init(NULL);
158 
159 	if (!cpu_has_counter) {
160 		mips_hpt_frequency = 0;
161 	} else if (mach && mach->measure_hpt_freq) {
162 		mips_hpt_frequency = mach->measure_hpt_freq();
163 	} else {
164 		np = of_get_cpu_node(0, NULL);
165 		if (!np) {
166 			pr_err("Failed to get CPU node\n");
167 			return;
168 		}
169 
170 		clk = of_clk_get(np, 0);
171 		if (IS_ERR(clk)) {
172 			pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
173 			return;
174 		}
175 
176 		mips_hpt_frequency = clk_get_rate(clk);
177 		clk_put(clk);
178 
179 		switch (boot_cpu_type()) {
180 		case CPU_20KC:
181 		case CPU_25KF:
182 			/* The counter runs at the CPU clock rate */
183 			break;
184 		default:
185 			/* The counter runs at half the CPU clock rate */
186 			mips_hpt_frequency /= 2;
187 			break;
188 		}
189 	}
190 
191 	timer_probe();
192 }
193 
194 void __init arch_init_irq(void)
195 {
196 	struct device_node *intc_node;
197 
198 	intc_node = of_find_compatible_node(NULL, NULL,
199 					    "mti,cpu-interrupt-controller");
200 	if (!cpu_has_veic && !intc_node)
201 		mips_cpu_irq_init();
202 	of_node_put(intc_node);
203 
204 	irqchip_init();
205 }
206 
207 void __init prom_free_prom_memory(void)
208 {
209 }
210