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 of_device_id rcar_rst_matches[] __initconst = {
 41	/* RZ/G1 is handled like R-Car Gen2 */
 42	{ .compatible = "renesas,r8a7742-rst", .data = &rcar_rst_gen2 },
 43	{ .compatible = "renesas,r8a7743-rst", .data = &rcar_rst_gen2 },
 44	{ .compatible = "renesas,r8a7744-rst", .data = &rcar_rst_gen2 },
 45	{ .compatible = "renesas,r8a7745-rst", .data = &rcar_rst_gen2 },
 46	{ .compatible = "renesas,r8a77470-rst", .data = &rcar_rst_gen2 },
 47	/* RZ/G2 is handled like R-Car Gen3 */
 48	{ .compatible = "renesas,r8a774a1-rst", .data = &rcar_rst_gen3 },
 49	{ .compatible = "renesas,r8a774b1-rst", .data = &rcar_rst_gen3 },
 50	{ .compatible = "renesas,r8a774c0-rst", .data = &rcar_rst_gen3 },
 51	{ .compatible = "renesas,r8a774e1-rst", .data = &rcar_rst_gen3 },
 52	/* R-Car Gen1 */
 53	{ .compatible = "renesas,r8a7778-reset-wdt", .data = &rcar_rst_gen1 },
 54	{ .compatible = "renesas,r8a7779-reset-wdt", .data = &rcar_rst_gen1 },
 55	/* R-Car Gen2 */
 56	{ .compatible = "renesas,r8a7790-rst", .data = &rcar_rst_gen2 },
 57	{ .compatible = "renesas,r8a7791-rst", .data = &rcar_rst_gen2 },
 58	{ .compatible = "renesas,r8a7792-rst", .data = &rcar_rst_gen2 },
 59	{ .compatible = "renesas,r8a7793-rst", .data = &rcar_rst_gen2 },
 60	{ .compatible = "renesas,r8a7794-rst", .data = &rcar_rst_gen2 },
 61	/* R-Car Gen3 */
 62	{ .compatible = "renesas,r8a7795-rst", .data = &rcar_rst_gen3 },
 63	{ .compatible = "renesas,r8a7796-rst", .data = &rcar_rst_gen3 },
 64	{ .compatible = "renesas,r8a77961-rst", .data = &rcar_rst_gen3 },
 65	{ .compatible = "renesas,r8a77965-rst", .data = &rcar_rst_gen3 },
 66	{ .compatible = "renesas,r8a77970-rst", .data = &rcar_rst_gen3 },
 67	{ .compatible = "renesas,r8a77980-rst", .data = &rcar_rst_gen3 },
 68	{ .compatible = "renesas,r8a77990-rst", .data = &rcar_rst_gen3 },
 69	{ .compatible = "renesas,r8a77995-rst", .data = &rcar_rst_gen3 },
 70	{ /* sentinel */ }
 71};
 72
 73static void __iomem *rcar_rst_base __initdata;
 74static u32 saved_mode __initdata;
 75
 76static int __init rcar_rst_init(void)
 77{
 78	const struct of_device_id *match;
 79	const struct rst_config *cfg;
 80	struct device_node *np;
 81	void __iomem *base;
 82	int error = 0;
 83
 84	np = of_find_matching_node_and_match(NULL, rcar_rst_matches, &match);
 85	if (!np)
 86		return -ENODEV;
 87
 88	base = of_iomap(np, 0);
 89	if (!base) {
 90		pr_warn("%pOF: Cannot map regs\n", np);
 91		error = -ENOMEM;
 92		goto out_put;
 93	}
 94
 95	rcar_rst_base = base;
 96	cfg = match->data;
 97	saved_mode = ioread32(base + cfg->modemr);
 98	if (cfg->configure) {
 99		error = cfg->configure(base);
100		if (error) {
101			pr_warn("%pOF: Cannot run SoC specific configuration\n",
102				np);
103			goto out_put;
104		}
105	}
106
107	pr_debug("%pOF: MODE = 0x%08x\n", np, saved_mode);
108
109out_put:
110	of_node_put(np);
111	return error;
112}
113
114int __init rcar_rst_read_mode_pins(u32 *mode)
115{
116	int error;
117
118	if (!rcar_rst_base) {
119		error = rcar_rst_init();
120		if (error)
121			return error;
122	}
123
124	*mode = saved_mode;
125	return 0;
126}