1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * R-Car Generation 2 Power management support
4  *
5  * Copyright (C) 2013 - 2015  Renesas Electronics Corporation
6  * Copyright (C) 2011  Renesas Solutions Corp.
7  * Copyright (C) 2011  Magnus Damm
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/ioport.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/smp.h>
15 #include <asm/io.h>
16 #include <asm/cputype.h>
17 #include "common.h"
18 #include "rcar-gen2.h"
19 
20 /* RST */
21 #define RST		0xe6160000
22 
23 #define CA15BAR		0x0020		/* CA15 Boot Address Register */
24 #define CA7BAR		0x0030		/* CA7 Boot Address Register */
25 #define CA15RESCNT	0x0040		/* CA15 Reset Control Register */
26 #define CA7RESCNT	0x0044		/* CA7 Reset Control Register */
27 
28 /* SYS Boot Address Register */
29 #define SBAR_BAREN	BIT(4)		/* SBAR is valid */
30 
31 /* Reset Control Registers */
32 #define CA15RESCNT_CODE	0xa5a50000
33 #define CA15RESCNT_CPUS	0xf		/* CPU0-3 */
34 #define CA7RESCNT_CODE	0x5a5a0000
35 #define CA7RESCNT_CPUS	0xf		/* CPU0-3 */
36 
37 /* On-chip RAM */
38 #define ICRAM1		0xe63c0000	/* Inter Connect RAM1 (4 KiB) */
39 
40 static inline u32 phys_to_sbar(phys_addr_t addr)
41 {
42 	return (addr >> 8) & 0xfffffc00;
43 }
44 
45 void __init rcar_gen2_pm_init(void)
46 {
47 	void __iomem *p;
48 	u32 bar;
49 	static int once;
50 	struct device_node *np;
51 	bool has_a7 = false;
52 	bool has_a15 = false;
53 	struct resource res;
54 	int error;
55 
56 	if (once++)
57 		return;
58 
59 	for_each_of_cpu_node(np) {
60 		if (of_device_is_compatible(np, "arm,cortex-a15"))
61 			has_a15 = true;
62 		else if (of_device_is_compatible(np, "arm,cortex-a7"))
63 			has_a7 = true;
64 	}
65 
66 	np = of_find_compatible_node(NULL, NULL, "renesas,smp-sram");
67 	if (!np) {
68 		/* No smp-sram in DT, fall back to hardcoded address */
69 		res = (struct resource)DEFINE_RES_MEM(ICRAM1,
70 						      shmobile_boot_size);
71 		goto map;
72 	}
73 
74 	error = of_address_to_resource(np, 0, &res);
75 	if (error) {
76 		pr_err("Failed to get smp-sram address: %d\n", error);
77 		return;
78 	}
79 
80 map:
81 	/* RAM for jump stub, because BAR requires 256KB aligned address */
82 	if (res.start & (256 * 1024 - 1) ||
83 	    resource_size(&res) < shmobile_boot_size) {
84 		pr_err("Invalid smp-sram region\n");
85 		return;
86 	}
87 
88 	p = ioremap(res.start, resource_size(&res));
89 	if (!p)
90 		return;
91 	/*
92 	 * install the reset vector, use the largest version if we have enough
93 	 * memory available
94 	 */
95 	if (resource_size(&res) >= shmobile_boot_size_gen2) {
96 		shmobile_boot_cpu_gen2 = read_cpuid_mpidr();
97 		memcpy_toio(p, shmobile_boot_vector_gen2,
98 			    shmobile_boot_size_gen2);
99 	} else {
100 		memcpy_toio(p, shmobile_boot_vector, shmobile_boot_size);
101 	}
102 	iounmap(p);
103 
104 	/* setup reset vectors */
105 	p = ioremap_nocache(RST, 0x63);
106 	bar = phys_to_sbar(res.start);
107 	if (has_a15) {
108 		writel_relaxed(bar, p + CA15BAR);
109 		writel_relaxed(bar | SBAR_BAREN, p + CA15BAR);
110 
111 		/* de-assert reset for CA15 CPUs */
112 		writel_relaxed((readl_relaxed(p + CA15RESCNT) &
113 				~CA15RESCNT_CPUS) | CA15RESCNT_CODE,
114 			       p + CA15RESCNT);
115 	}
116 	if (has_a7) {
117 		writel_relaxed(bar, p + CA7BAR);
118 		writel_relaxed(bar | SBAR_BAREN, p + CA7BAR);
119 
120 		/* de-assert reset for CA7 CPUs */
121 		writel_relaxed((readl_relaxed(p + CA7RESCNT) &
122 				~CA7RESCNT_CPUS) | CA7RESCNT_CODE,
123 			       p + CA7RESCNT);
124 	}
125 	iounmap(p);
126 
127 	shmobile_smp_apmu_suspend_init();
128 }
129