xref: /linux/drivers/soc/renesas/rcar-rst.c (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
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		0x0010
16 
17 #define CR7BAR			0x0070
18 #define CR7BAREN		BIT(4)
19 #define CR7BAR_MASK		0xFFFC0000
20 
21 static void __iomem *rcar_rst_base;
22 static u32 saved_mode __initdata;
23 static int (*rcar_rst_set_rproc_boot_addr_func)(u64 boot_addr);
24 
25 static int rcar_rst_enable_wdt_reset(void __iomem *base)
26 {
27 	iowrite32(WDTRSTCR_RESET, base + WDTRSTCR);
28 	return 0;
29 }
30 
31 static int rcar_rst_v3u_enable_wdt_reset(void __iomem *base)
32 {
33 	iowrite32(WDTRSTCR_RESET, base + GEN4_WDTRSTCR);
34 	return 0;
35 }
36 
37 /*
38  * Most of the R-Car Gen3 SoCs have an ARM Realtime Core.
39  * Firmware boot address has to be set in CR7BAR before
40  * starting the realtime core.
41  * Boot address must be aligned on a 256k boundary.
42  */
43 static int rcar_rst_set_gen3_rproc_boot_addr(u64 boot_addr)
44 {
45 	if (boot_addr & ~(u64)CR7BAR_MASK) {
46 		pr_err("Invalid boot address got %llx\n", boot_addr);
47 		return -EINVAL;
48 	}
49 
50 	iowrite32(boot_addr, rcar_rst_base + CR7BAR);
51 	iowrite32(boot_addr | CR7BAREN, rcar_rst_base + CR7BAR);
52 
53 	return 0;
54 }
55 
56 struct rst_config {
57 	unsigned int modemr;		/* Mode Monitoring Register Offset */
58 	int (*configure)(void __iomem *base);	/* Platform specific config */
59 	int (*set_rproc_boot_addr)(u64 boot_addr);
60 };
61 
62 static const struct rst_config rcar_rst_gen1 __initconst = {
63 	.modemr = 0x20,
64 };
65 
66 static const struct rst_config rcar_rst_gen2 __initconst = {
67 	.modemr = 0x60,
68 	.configure = rcar_rst_enable_wdt_reset,
69 };
70 
71 static const struct rst_config rcar_rst_gen3 __initconst = {
72 	.modemr = 0x60,
73 	.set_rproc_boot_addr = rcar_rst_set_gen3_rproc_boot_addr,
74 };
75 
76 /* V3U firmware doesn't enable WDT reset and there won't be updates anymore */
77 static const struct rst_config rcar_rst_v3u __initconst = {
78 	.modemr = 0x00,		/* MODEMR0 and it has CPG related bits */
79 	.configure = rcar_rst_v3u_enable_wdt_reset,
80 };
81 
82 static const struct rst_config rcar_rst_gen4 __initconst = {
83 	.modemr = 0x00,		/* MODEMR0 and it has CPG related bits */
84 };
85 
86 static const struct of_device_id rcar_rst_matches[] __initconst = {
87 	/* RZ/G1 is handled like R-Car Gen2 */
88 	{ .compatible = "renesas,r8a7742-rst", .data = &rcar_rst_gen2 },
89 	{ .compatible = "renesas,r8a7743-rst", .data = &rcar_rst_gen2 },
90 	{ .compatible = "renesas,r8a7744-rst", .data = &rcar_rst_gen2 },
91 	{ .compatible = "renesas,r8a7745-rst", .data = &rcar_rst_gen2 },
92 	{ .compatible = "renesas,r8a77470-rst", .data = &rcar_rst_gen2 },
93 	/* RZ/G2 is handled like R-Car Gen3 */
94 	{ .compatible = "renesas,r8a774a1-rst", .data = &rcar_rst_gen3 },
95 	{ .compatible = "renesas,r8a774b1-rst", .data = &rcar_rst_gen3 },
96 	{ .compatible = "renesas,r8a774c0-rst", .data = &rcar_rst_gen3 },
97 	{ .compatible = "renesas,r8a774e1-rst", .data = &rcar_rst_gen3 },
98 	/* R-Car Gen1 */
99 	{ .compatible = "renesas,r8a7778-reset-wdt", .data = &rcar_rst_gen1 },
100 	{ .compatible = "renesas,r8a7779-reset-wdt", .data = &rcar_rst_gen1 },
101 	/* R-Car Gen2 */
102 	{ .compatible = "renesas,r8a7790-rst", .data = &rcar_rst_gen2 },
103 	{ .compatible = "renesas,r8a7791-rst", .data = &rcar_rst_gen2 },
104 	{ .compatible = "renesas,r8a7792-rst", .data = &rcar_rst_gen2 },
105 	{ .compatible = "renesas,r8a7793-rst", .data = &rcar_rst_gen2 },
106 	{ .compatible = "renesas,r8a7794-rst", .data = &rcar_rst_gen2 },
107 	/* R-Car Gen3 */
108 	{ .compatible = "renesas,r8a7795-rst", .data = &rcar_rst_gen3 },
109 	{ .compatible = "renesas,r8a7796-rst", .data = &rcar_rst_gen3 },
110 	{ .compatible = "renesas,r8a77961-rst", .data = &rcar_rst_gen3 },
111 	{ .compatible = "renesas,r8a77965-rst", .data = &rcar_rst_gen3 },
112 	{ .compatible = "renesas,r8a77970-rst", .data = &rcar_rst_gen3 },
113 	{ .compatible = "renesas,r8a77980-rst", .data = &rcar_rst_gen3 },
114 	{ .compatible = "renesas,r8a77990-rst", .data = &rcar_rst_gen3 },
115 	{ .compatible = "renesas,r8a77995-rst", .data = &rcar_rst_gen3 },
116 	/* R-Car Gen4 */
117 	{ .compatible = "renesas,r8a779a0-rst", .data = &rcar_rst_v3u },
118 	{ .compatible = "renesas,r8a779f0-rst", .data = &rcar_rst_gen4 },
119 	{ .compatible = "renesas,r8a779g0-rst", .data = &rcar_rst_gen4 },
120 	{ .compatible = "renesas,r8a779h0-rst", .data = &rcar_rst_gen4 },
121 	{ /* sentinel */ }
122 };
123 
124 static int __init rcar_rst_init(void)
125 {
126 	const struct of_device_id *match;
127 	const struct rst_config *cfg;
128 	struct device_node *np;
129 	void __iomem *base;
130 	int error = 0;
131 
132 	np = of_find_matching_node_and_match(NULL, rcar_rst_matches, &match);
133 	if (!np)
134 		return -ENODEV;
135 
136 	base = of_iomap(np, 0);
137 	if (!base) {
138 		pr_warn("%pOF: Cannot map regs\n", np);
139 		error = -ENOMEM;
140 		goto out_put;
141 	}
142 
143 	rcar_rst_base = base;
144 	cfg = match->data;
145 	rcar_rst_set_rproc_boot_addr_func = cfg->set_rproc_boot_addr;
146 
147 	saved_mode = ioread32(base + cfg->modemr);
148 	if (cfg->configure) {
149 		error = cfg->configure(base);
150 		if (error) {
151 			pr_warn("%pOF: Cannot run SoC specific configuration\n",
152 				np);
153 			goto out_put;
154 		}
155 	}
156 
157 	pr_debug("%pOF: MODE = 0x%08x\n", np, saved_mode);
158 
159 out_put:
160 	of_node_put(np);
161 	return error;
162 }
163 
164 int __init rcar_rst_read_mode_pins(u32 *mode)
165 {
166 	int error;
167 
168 	if (!rcar_rst_base) {
169 		error = rcar_rst_init();
170 		if (error)
171 			return error;
172 	}
173 
174 	*mode = saved_mode;
175 	return 0;
176 }
177 
178 int rcar_rst_set_rproc_boot_addr(u64 boot_addr)
179 {
180 	if (!rcar_rst_set_rproc_boot_addr_func)
181 		return -EIO;
182 
183 	return rcar_rst_set_rproc_boot_addr_func(boot_addr);
184 }
185 EXPORT_SYMBOL_GPL(rcar_rst_set_rproc_boot_addr);
186