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
rcar_rst_enable_wdt_reset(void __iomem * base)26 static int rcar_rst_enable_wdt_reset(void __iomem *base)
27 {
28 iowrite32(WDTRSTCR_RESET, base + WDTRSTCR);
29 return 0;
30 }
31
rcar_rst_v3u_enable_wdt_reset(void __iomem * base)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 */
rcar_rst_set_gen3_rproc_boot_addr(u64 boot_addr)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
rcar_rst_init(void)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
rcar_rst_read_mode_pins(u32 * mode)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
rcar_rst_set_rproc_boot_addr(u64 boot_addr)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