xref: /linux/drivers/soc/renesas/rcar-rst.c (revision d30c1683aaecb93d2ab95685dc4300a33d3cea7a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * R-Car Gen1 RESET/WDT, R-Car Gen2, Gen3, and RZ/G RST Driver
4  *
5  * Copyright (C) 2016 Glider bvba
6  */
7 
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/of_address.h>
11 #include <linux/soc/renesas/rcar-rst.h>
12 
13 #define WDTRSTCR_RESET		0xA55A0002
14 #define WDTRSTCR		0x0054
15 #define GEN4_WDTRSTCR_RESET	0xA55A8002
16 #define GEN4_WDTRSTCR		0x0010
17 
18 #define CR7BAR			0x0070
19 #define CR7BAREN		BIT(4)
20 #define CR7BAR_MASK		0xFFFC0000
21 
22 static void __iomem *rcar_rst_base;
23 static u32 saved_mode __initdata;
24 static int (*rcar_rst_set_rproc_boot_addr_func)(u64 boot_addr);
25 
26 static int rcar_rst_enable_wdt_reset(void __iomem *base)
27 {
28 	iowrite32(WDTRSTCR_RESET, base + WDTRSTCR);
29 	return 0;
30 }
31 
32 static int rcar_rst_v3u_enable_wdt_reset(void __iomem *base)
33 {
34 	iowrite32(GEN4_WDTRSTCR_RESET, base + GEN4_WDTRSTCR);
35 	return 0;
36 }
37 
38 /*
39  * Most of the R-Car Gen3 SoCs have an ARM Realtime Core.
40  * Firmware boot address has to be set in CR7BAR before
41  * starting the realtime core.
42  * Boot address must be aligned on a 256k boundary.
43  */
44 static int rcar_rst_set_gen3_rproc_boot_addr(u64 boot_addr)
45 {
46 	if (boot_addr & ~(u64)CR7BAR_MASK) {
47 		pr_err("Invalid boot address got %llx\n", boot_addr);
48 		return -EINVAL;
49 	}
50 
51 	iowrite32(boot_addr, rcar_rst_base + CR7BAR);
52 	iowrite32(boot_addr | CR7BAREN, rcar_rst_base + CR7BAR);
53 
54 	return 0;
55 }
56 
57 struct rst_config {
58 	unsigned int modemr;		/* Mode Monitoring Register Offset */
59 	int (*configure)(void __iomem *base);	/* Platform specific config */
60 	int (*set_rproc_boot_addr)(u64 boot_addr);
61 };
62 
63 static const struct rst_config rcar_rst_gen1 __initconst = {
64 	.modemr = 0x20,
65 };
66 
67 static const struct rst_config rcar_rst_gen2 __initconst = {
68 	.modemr = 0x60,
69 	.configure = rcar_rst_enable_wdt_reset,
70 };
71 
72 static const struct rst_config rcar_rst_gen3 __initconst = {
73 	.modemr = 0x60,
74 	.set_rproc_boot_addr = rcar_rst_set_gen3_rproc_boot_addr,
75 };
76 
77 /* V3U firmware doesn't enable WDT reset and there won't be updates anymore */
78 static const struct rst_config rcar_rst_v3u __initconst = {
79 	.modemr = 0x00,		/* MODEMR0 and it has CPG related bits */
80 	.configure = rcar_rst_v3u_enable_wdt_reset,
81 };
82 
83 static const struct rst_config rcar_rst_gen4 __initconst = {
84 	.modemr = 0x00,		/* MODEMR0 and it has CPG related bits */
85 };
86 
87 static const struct of_device_id rcar_rst_matches[] __initconst = {
88 	/* RZ/G1 is handled like R-Car Gen2 */
89 	{ .compatible = "renesas,r8a7742-rst", .data = &rcar_rst_gen2 },
90 	{ .compatible = "renesas,r8a7743-rst", .data = &rcar_rst_gen2 },
91 	{ .compatible = "renesas,r8a7744-rst", .data = &rcar_rst_gen2 },
92 	{ .compatible = "renesas,r8a7745-rst", .data = &rcar_rst_gen2 },
93 	{ .compatible = "renesas,r8a77470-rst", .data = &rcar_rst_gen2 },
94 	/* RZ/G2 is handled like R-Car Gen3 */
95 	{ .compatible = "renesas,r8a774a1-rst", .data = &rcar_rst_gen3 },
96 	{ .compatible = "renesas,r8a774b1-rst", .data = &rcar_rst_gen3 },
97 	{ .compatible = "renesas,r8a774c0-rst", .data = &rcar_rst_gen3 },
98 	{ .compatible = "renesas,r8a774e1-rst", .data = &rcar_rst_gen3 },
99 	/* R-Car Gen1 */
100 	{ .compatible = "renesas,r8a7778-reset-wdt", .data = &rcar_rst_gen1 },
101 	{ .compatible = "renesas,r8a7779-reset-wdt", .data = &rcar_rst_gen1 },
102 	/* R-Car Gen2 */
103 	{ .compatible = "renesas,r8a7790-rst", .data = &rcar_rst_gen2 },
104 	{ .compatible = "renesas,r8a7791-rst", .data = &rcar_rst_gen2 },
105 	{ .compatible = "renesas,r8a7792-rst", .data = &rcar_rst_gen2 },
106 	{ .compatible = "renesas,r8a7793-rst", .data = &rcar_rst_gen2 },
107 	{ .compatible = "renesas,r8a7794-rst", .data = &rcar_rst_gen2 },
108 	/* R-Car Gen3 */
109 	{ .compatible = "renesas,r8a7795-rst", .data = &rcar_rst_gen3 },
110 	{ .compatible = "renesas,r8a7796-rst", .data = &rcar_rst_gen3 },
111 	{ .compatible = "renesas,r8a77961-rst", .data = &rcar_rst_gen3 },
112 	{ .compatible = "renesas,r8a77965-rst", .data = &rcar_rst_gen3 },
113 	{ .compatible = "renesas,r8a77970-rst", .data = &rcar_rst_gen3 },
114 	{ .compatible = "renesas,r8a77980-rst", .data = &rcar_rst_gen3 },
115 	{ .compatible = "renesas,r8a77990-rst", .data = &rcar_rst_gen3 },
116 	{ .compatible = "renesas,r8a77995-rst", .data = &rcar_rst_gen3 },
117 	/* R-Car Gen4 */
118 	{ .compatible = "renesas,r8a779a0-rst", .data = &rcar_rst_v3u },
119 	{ .compatible = "renesas,r8a779f0-rst", .data = &rcar_rst_gen4 },
120 	{ .compatible = "renesas,r8a779g0-rst", .data = &rcar_rst_gen4 },
121 	{ .compatible = "renesas,r8a779h0-rst", .data = &rcar_rst_gen4 },
122 	{ /* sentinel */ }
123 };
124 
125 static int __init rcar_rst_init(void)
126 {
127 	const struct of_device_id *match;
128 	const struct rst_config *cfg;
129 	struct device_node *np;
130 	void __iomem *base;
131 	int error = 0;
132 
133 	np = of_find_matching_node_and_match(NULL, rcar_rst_matches, &match);
134 	if (!np)
135 		return -ENODEV;
136 
137 	base = of_iomap(np, 0);
138 	if (!base) {
139 		pr_warn("%pOF: Cannot map regs\n", np);
140 		error = -ENOMEM;
141 		goto out_put;
142 	}
143 
144 	rcar_rst_base = base;
145 	cfg = match->data;
146 	rcar_rst_set_rproc_boot_addr_func = cfg->set_rproc_boot_addr;
147 
148 	saved_mode = ioread32(base + cfg->modemr);
149 	if (cfg->configure) {
150 		error = cfg->configure(base);
151 		if (error) {
152 			pr_warn("%pOF: Cannot run SoC specific configuration\n",
153 				np);
154 			goto out_put;
155 		}
156 	}
157 
158 	pr_debug("%pOF: MODE = 0x%08x\n", np, saved_mode);
159 
160 out_put:
161 	of_node_put(np);
162 	return error;
163 }
164 
165 int __init rcar_rst_read_mode_pins(u32 *mode)
166 {
167 	int error;
168 
169 	if (!rcar_rst_base) {
170 		error = rcar_rst_init();
171 		if (error)
172 			return error;
173 	}
174 
175 	*mode = saved_mode;
176 	return 0;
177 }
178 
179 int rcar_rst_set_rproc_boot_addr(u64 boot_addr)
180 {
181 	if (!rcar_rst_set_rproc_boot_addr_func)
182 		return -EIO;
183 
184 	return rcar_rst_set_rproc_boot_addr_func(boot_addr);
185 }
186 EXPORT_SYMBOL_GPL(rcar_rst_set_rproc_boot_addr);
187