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