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
rcar_rst_enable_wdt_reset(void __iomem * base)25 static int rcar_rst_enable_wdt_reset(void __iomem *base)
26 {
27 iowrite32(WDTRSTCR_RESET, base + WDTRSTCR);
28 return 0;
29 }
30
rcar_rst_v3u_enable_wdt_reset(void __iomem * base)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 */
rcar_rst_set_gen3_rproc_boot_addr(u64 boot_addr)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
rcar_rst_init(void)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
rcar_rst_read_mode_pins(u32 * mode)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
rcar_rst_set_rproc_boot_addr(u64 boot_addr)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