drivers/soc/renesas/rcar-rst.c

   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 __iomem *base);   /* Platform specific config */
  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 rst_config rcar_rst_r8a779a0 __initconst = {
  41         .modemr = 0x00,         /* MODEMR0 and it has CPG related bits */
  42 };
  43
  44 static 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
  79 static void __iomem *rcar_rst_base __initdata;
  80 static u32 saved_mode __initdata;
  81
  82 static 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
 115 out_put:
 116         of_node_put(np);
 117         return error;
 118 }
 119
 120 int __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 }