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