1 /* 2 * R-Car Gen1 RESET/WDT, R-Car Gen2, Gen3, and RZ/G RST Driver 3 * 4 * Copyright (C) 2016 Glider bvba 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/err.h> 12 #include <linux/io.h> 13 #include <linux/of_address.h> 14 #include <linux/soc/renesas/rcar-rst.h> 15 16 #define WDTRSTCR_RESET 0xA55A0002 17 #define WDTRSTCR 0x0054 18 19 static int rcar_rst_enable_wdt_reset(void __iomem *base) 20 { 21 iowrite32(WDTRSTCR_RESET, base + WDTRSTCR); 22 return 0; 23 } 24 25 struct rst_config { 26 unsigned int modemr; /* Mode Monitoring Register Offset */ 27 int (*configure)(void *base); /* Platform specific configuration */ 28 }; 29 30 static const struct rst_config rcar_rst_gen1 __initconst = { 31 .modemr = 0x20, 32 }; 33 34 static const struct rst_config rcar_rst_gen2 __initconst = { 35 .modemr = 0x60, 36 .configure = rcar_rst_enable_wdt_reset, 37 }; 38 39 static const struct rst_config rcar_rst_gen3 __initconst = { 40 .modemr = 0x60, 41 }; 42 43 static const struct of_device_id rcar_rst_matches[] __initconst = { 44 /* RZ/G is handled like R-Car Gen2 */ 45 { .compatible = "renesas,r8a7743-rst", .data = &rcar_rst_gen2 }, 46 { .compatible = "renesas,r8a7745-rst", .data = &rcar_rst_gen2 }, 47 { .compatible = "renesas,r8a77470-rst", .data = &rcar_rst_gen2 }, 48 /* R-Car Gen1 */ 49 { .compatible = "renesas,r8a7778-reset-wdt", .data = &rcar_rst_gen1 }, 50 { .compatible = "renesas,r8a7779-reset-wdt", .data = &rcar_rst_gen1 }, 51 /* R-Car Gen2 */ 52 { .compatible = "renesas,r8a7790-rst", .data = &rcar_rst_gen2 }, 53 { .compatible = "renesas,r8a7791-rst", .data = &rcar_rst_gen2 }, 54 { .compatible = "renesas,r8a7792-rst", .data = &rcar_rst_gen2 }, 55 { .compatible = "renesas,r8a7793-rst", .data = &rcar_rst_gen2 }, 56 { .compatible = "renesas,r8a7794-rst", .data = &rcar_rst_gen2 }, 57 /* R-Car Gen3 */ 58 { .compatible = "renesas,r8a7795-rst", .data = &rcar_rst_gen3 }, 59 { .compatible = "renesas,r8a7796-rst", .data = &rcar_rst_gen3 }, 60 { .compatible = "renesas,r8a77965-rst", .data = &rcar_rst_gen3 }, 61 { .compatible = "renesas,r8a77970-rst", .data = &rcar_rst_gen3 }, 62 { .compatible = "renesas,r8a77980-rst", .data = &rcar_rst_gen3 }, 63 { .compatible = "renesas,r8a77990-rst", .data = &rcar_rst_gen3 }, 64 { .compatible = "renesas,r8a77995-rst", .data = &rcar_rst_gen3 }, 65 { /* sentinel */ } 66 }; 67 68 static void __iomem *rcar_rst_base __initdata; 69 static u32 saved_mode __initdata; 70 71 static int __init rcar_rst_init(void) 72 { 73 const struct of_device_id *match; 74 const struct rst_config *cfg; 75 struct device_node *np; 76 void __iomem *base; 77 int error = 0; 78 79 np = of_find_matching_node_and_match(NULL, rcar_rst_matches, &match); 80 if (!np) 81 return -ENODEV; 82 83 base = of_iomap(np, 0); 84 if (!base) { 85 pr_warn("%pOF: Cannot map regs\n", np); 86 error = -ENOMEM; 87 goto out_put; 88 } 89 90 rcar_rst_base = base; 91 cfg = match->data; 92 saved_mode = ioread32(base + cfg->modemr); 93 if (cfg->configure) { 94 error = cfg->configure(base); 95 if (error) { 96 pr_warn("%pOF: Cannot run SoC specific configuration\n", 97 np); 98 goto out_put; 99 } 100 } 101 102 pr_debug("%pOF: MODE = 0x%08x\n", np, saved_mode); 103 104 out_put: 105 of_node_put(np); 106 return error; 107 } 108 109 int __init rcar_rst_read_mode_pins(u32 *mode) 110 { 111 int error; 112 113 if (!rcar_rst_base) { 114 error = rcar_rst_init(); 115 if (error) 116 return error; 117 } 118 119 *mode = saved_mode; 120 return 0; 121 } 122