xref: /kernel/linux/linux-5.10/arch/mips/generic/init.c (revision 8c2ecf20)
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
23static __initconst const void *fdt;
24static __initconst const struct mips_machine *mach;
25static __initconst const void *mach_match_data;
26
27void __init prom_init(void)
28{
29	plat_get_fdt();
30	BUG_ON(!fdt);
31}
32
33void __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
88void __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
103void __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
112void __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
124int __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
151void __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
193void __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
206void __init prom_free_prom_memory(void)
207{
208}
209