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
16static int rcar_rst_enable_wdt_reset(void __iomem *base)
17{
18	iowrite32(WDTRSTCR_RESET, base + WDTRSTCR);
19	return 0;
20}
21
22struct rst_config {
23	unsigned int modemr;		/* Mode Monitoring Register Offset */
24	int (*configure)(void __iomem *base);	/* Platform specific config */
25};
26
27static const struct rst_config rcar_rst_gen1 __initconst = {
28	.modemr = 0x20,
29};
30
31static const struct rst_config rcar_rst_gen2 __initconst = {
32	.modemr = 0x60,
33	.configure = rcar_rst_enable_wdt_reset,
34};
35
36static const struct rst_config rcar_rst_gen3 __initconst = {
37	.modemr = 0x60,
38};
39
40static const struct rst_config rcar_rst_r8a779a0 __initconst = {
41	.modemr = 0x00,		/* MODEMR0 and it has CPG related bits */
42};
43
44static const struct of_device_id rcar_rst_matches[] __initconst = {
45	/* RZ/G1 is handled like R-Car Gen2 */
46	{ .compatible = "renesas,r8a7742-rst", .data = &rcar_rst_gen2 },
47	{ .compatible = "renesas,r8a7743-rst", .data = &rcar_rst_gen2 },
48	{ .compatible = "renesas,r8a7744-rst", .data = &rcar_rst_gen2 },
49	{ .compatible = "renesas,r8a7745-rst", .data = &rcar_rst_gen2 },
50	{ .compatible = "renesas,r8a77470-rst", .data = &rcar_rst_gen2 },
51	/* RZ/G2 is handled like R-Car Gen3 */
52	{ .compatible = "renesas,r8a774a1-rst", .data = &rcar_rst_gen3 },
53	{ .compatible = "renesas,r8a774b1-rst", .data = &rcar_rst_gen3 },
54	{ .compatible = "renesas,r8a774c0-rst", .data = &rcar_rst_gen3 },
55	{ .compatible = "renesas,r8a774e1-rst", .data = &rcar_rst_gen3 },
56	/* R-Car Gen1 */
57	{ .compatible = "renesas,r8a7778-reset-wdt", .data = &rcar_rst_gen1 },
58	{ .compatible = "renesas,r8a7779-reset-wdt", .data = &rcar_rst_gen1 },
59	/* R-Car Gen2 */
60	{ .compatible = "renesas,r8a7790-rst", .data = &rcar_rst_gen2 },
61	{ .compatible = "renesas,r8a7791-rst", .data = &rcar_rst_gen2 },
62	{ .compatible = "renesas,r8a7792-rst", .data = &rcar_rst_gen2 },
63	{ .compatible = "renesas,r8a7793-rst", .data = &rcar_rst_gen2 },
64	{ .compatible = "renesas,r8a7794-rst", .data = &rcar_rst_gen2 },
65	/* R-Car Gen3 */
66	{ .compatible = "renesas,r8a7795-rst", .data = &rcar_rst_gen3 },
67	{ .compatible = "renesas,r8a7796-rst", .data = &rcar_rst_gen3 },
68	{ .compatible = "renesas,r8a77961-rst", .data = &rcar_rst_gen3 },
69	{ .compatible = "renesas,r8a77965-rst", .data = &rcar_rst_gen3 },
70	{ .compatible = "renesas,r8a77970-rst", .data = &rcar_rst_gen3 },
71	{ .compatible = "renesas,r8a77980-rst", .data = &rcar_rst_gen3 },
72	{ .compatible = "renesas,r8a77990-rst", .data = &rcar_rst_gen3 },
73	{ .compatible = "renesas,r8a77995-rst", .data = &rcar_rst_gen3 },
74	/* R-Car V3U */
75	{ .compatible = "renesas,r8a779a0-rst", .data = &rcar_rst_r8a779a0 },
76	{ /* sentinel */ }
77};
78
79static void __iomem *rcar_rst_base __initdata;
80static u32 saved_mode __initdata;
81
82static int __init rcar_rst_init(void)
83{
84	const struct of_device_id *match;
85	const struct rst_config *cfg;
86	struct device_node *np;
87	void __iomem *base;
88	int error = 0;
89
90	np = of_find_matching_node_and_match(NULL, rcar_rst_matches, &match);
91	if (!np)
92		return -ENODEV;
93
94	base = of_iomap(np, 0);
95	if (!base) {
96		pr_warn("%pOF: Cannot map regs\n", np);
97		error = -ENOMEM;
98		goto out_put;
99	}
100
101	rcar_rst_base = base;
102	cfg = match->data;
103	saved_mode = ioread32(base + cfg->modemr);
104	if (cfg->configure) {
105		error = cfg->configure(base);
106		if (error) {
107			pr_warn("%pOF: Cannot run SoC specific configuration\n",
108				np);
109			goto out_put;
110		}
111	}
112
113	pr_debug("%pOF: MODE = 0x%08x\n", np, saved_mode);
114
115out_put:
116	of_node_put(np);
117	return error;
118}
119
120int __init rcar_rst_read_mode_pins(u32 *mode)
121{
122	int error;
123
124	if (!rcar_rst_base) {
125		error = rcar_rst_init();
126		if (error)
127			return error;
128	}
129
130	*mode = saved_mode;
131	return 0;
132}
133