drivers/power/reset/ocelot-reset.c

   1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
   2 /*
   3  * Microsemi MIPS SoC reset driver
   4  *
   5  * License: Dual MIT/GPL
   6  * Copyright (c) 2017 Microsemi Corporation
   7  */
   8 #include <linux/delay.h>
   9 #include <linux/io.h>
  10 #include <linux/notifier.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/property.h>
  15 #include <linux/reboot.h>
  16 #include <linux/regmap.h>
  17
  18 struct reset_props {
  19         const char *syscon;
  20         u32 protect_reg;
  21         u32 vcore_protect;
  22         u32 if_si_owner_bit;
  23 };
  24
  25 struct ocelot_reset_context {
  26         void __iomem *base;
  27         struct regmap *cpu_ctrl;
  28         const struct reset_props *props;
  29         struct notifier_block restart_handler;
  30 };
  31
  32 #define BIT_OFF_INVALID                         32
  33
  34 #define SOFT_CHIP_RST BIT(0)
  35
  36 #define ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL   0x24
  37 #define IF_SI_OWNER_MASK                        GENMASK(1, 0)
  38 #define IF_SI_OWNER_SISL                        0
  39 #define IF_SI_OWNER_SIBM                        1
  40 #define IF_SI_OWNER_SIMC                        2
  41
  42 static int ocelot_restart_handle(struct notifier_block *this,
  43                                  unsigned long mode, void *cmd)
  44 {
  45         struct ocelot_reset_context *ctx = container_of(this, struct
  46                                                         ocelot_reset_context,
  47                                                         restart_handler);
  48         u32 if_si_owner_bit = ctx->props->if_si_owner_bit;
  49
  50         /* Make sure the core is not protected from reset */
  51         regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg,
  52                            ctx->props->vcore_protect, 0);
  53
  54         /* Make the SI back to boot mode */
  55         if (if_si_owner_bit != BIT_OFF_INVALID)
  56                 regmap_update_bits(ctx->cpu_ctrl,
  57                                    ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL,
  58                                    IF_SI_OWNER_MASK << if_si_owner_bit,
  59                                    IF_SI_OWNER_SIBM << if_si_owner_bit);
  60
  61         pr_emerg("Resetting SoC\n");
  62
  63         writel(SOFT_CHIP_RST, ctx->base);
  64
  65         pr_emerg("Unable to restart system\n");
  66         return NOTIFY_DONE;
  67 }
  68
  69 static int ocelot_reset_probe(struct platform_device *pdev)
  70 {
  71         struct ocelot_reset_context *ctx;
  72         struct device *dev = &pdev->dev;
  73         int err;
  74
  75         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
  76         if (!ctx)
  77                 return -ENOMEM;
  78
  79         ctx->base = devm_platform_ioremap_resource(pdev, 0);
  80         if (IS_ERR(ctx->base))
  81                 return PTR_ERR(ctx->base);
  82
  83         ctx->props = device_get_match_data(dev);
  84
  85         ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible(ctx->props->syscon);
  86         if (IS_ERR(ctx->cpu_ctrl)) {
  87                 dev_err(dev, "No syscon map: %s\n", ctx->props->syscon);
  88                 return PTR_ERR(ctx->cpu_ctrl);
  89         }
  90
  91         ctx->restart_handler.notifier_call = ocelot_restart_handle;
  92         ctx->restart_handler.priority = 192;
  93         err = register_restart_handler(&ctx->restart_handler);
  94         if (err)
  95                 dev_err(dev, "can't register restart notifier (err=%d)\n", err);
  96
  97         return err;
  98 }
  99
 100 static const struct reset_props reset_props_jaguar2 = {
 101         .syscon          = "mscc,ocelot-cpu-syscon",
 102         .protect_reg     = 0x20,
 103         .vcore_protect   = BIT(2),
 104         .if_si_owner_bit = 6,
 105 };
 106
 107 static const struct reset_props reset_props_luton = {
 108         .syscon          = "mscc,ocelot-cpu-syscon",
 109         .protect_reg     = 0x20,
 110         .vcore_protect   = BIT(2),
 111         .if_si_owner_bit = BIT_OFF_INVALID, /* n/a */
 112 };
 113
 114 static const struct reset_props reset_props_ocelot = {
 115         .syscon          = "mscc,ocelot-cpu-syscon",
 116         .protect_reg     = 0x20,
 117         .vcore_protect   = BIT(2),
 118         .if_si_owner_bit = 4,
 119 };
 120
 121 static const struct reset_props reset_props_sparx5 = {
 122         .syscon          = "microchip,sparx5-cpu-syscon",
 123         .protect_reg     = 0x84,
 124         .vcore_protect   = BIT(10),
 125         .if_si_owner_bit = 6,
 126 };
 127
 128 static const struct of_device_id ocelot_reset_of_match[] = {
 129         {
 130                 .compatible = "mscc,jaguar2-chip-reset",
 131                 .data = &reset_props_jaguar2
 132         }, {
 133                 .compatible = "mscc,luton-chip-reset",
 134                 .data = &reset_props_luton
 135         }, {
 136                 .compatible = "mscc,ocelot-chip-reset",
 137                 .data = &reset_props_ocelot
 138         }, {
 139                 .compatible = "microchip,sparx5-chip-reset",
 140                 .data = &reset_props_sparx5
 141         },
 142         { /*sentinel*/ }
 143 };
 144
 145 static struct platform_driver ocelot_reset_driver = {
 146         .probe = ocelot_reset_probe,
 147         .driver = {
 148                 .name = "ocelot-chip-reset",
 149                 .of_match_table = ocelot_reset_of_match,
 150         },
 151 };
 152 builtin_platform_driver(ocelot_reset_driver);