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