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/mfd/syscon.h>
  12 #include <linux/of_address.h>
  13 #include <linux/of_device.h>
  14 #include <linux/platform_device.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 SOFT_CHIP_RST BIT(0)
  33
  34 #define ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL   0x24
  35 #define IF_SI_OWNER_MASK                        GENMASK(1, 0)
  36 #define IF_SI_OWNER_SISL                        0
  37 #define IF_SI_OWNER_SIBM                        1
  38 #define IF_SI_OWNER_SIMC                        2
  39
  40 static int ocelot_restart_handle(struct notifier_block *this,
  41                                  unsigned long mode, void *cmd)
  42 {
  43         struct ocelot_reset_context *ctx = container_of(this, struct
  44                                                         ocelot_reset_context,
  45                                                         restart_handler);
  46         u32 if_si_owner_bit = ctx->props->if_si_owner_bit;
  47
  48         /* Make sure the core is not protected from reset */
  49         regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg,
  50                            ctx->props->vcore_protect, 0);
  51
  52         /* Make the SI back to boot mode */
  53         regmap_update_bits(ctx->cpu_ctrl, ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL,
  54                            IF_SI_OWNER_MASK << if_si_owner_bit,
  55                            IF_SI_OWNER_SIBM << if_si_owner_bit);
  56
  57         pr_emerg("Resetting SoC\n");
  58
  59         writel(SOFT_CHIP_RST, ctx->base);
  60
  61         pr_emerg("Unable to restart system\n");
  62         return NOTIFY_DONE;
  63 }
  64
  65 static int ocelot_reset_probe(struct platform_device *pdev)
  66 {
  67         struct ocelot_reset_context *ctx;
  68         struct resource *res;
  69
  70         struct device *dev = &pdev->dev;
  71         int err;
  72
  73         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
  74         if (!ctx)
  75                 return -ENOMEM;
  76
  77         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  78         ctx->base = devm_ioremap_resource(dev, res);
  79         if (IS_ERR(ctx->base))
  80                 return PTR_ERR(ctx->base);
  81
  82         ctx->props = device_get_match_data(dev);
  83
  84         ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible(ctx->props->syscon);
  85         if (IS_ERR(ctx->cpu_ctrl)) {
  86                 dev_err(dev, "No syscon map: %s\n", ctx->props->syscon);
  87                 return PTR_ERR(ctx->cpu_ctrl);
  88         }
  89
  90         ctx->restart_handler.notifier_call = ocelot_restart_handle;
  91         ctx->restart_handler.priority = 192;
  92         err = register_restart_handler(&ctx->restart_handler);
  93         if (err)
  94                 dev_err(dev, "can't register restart notifier (err=%d)\n", err);
  95
  96         return err;
  97 }
  98
  99 static const struct reset_props reset_props_ocelot = {
 100         .syscon          = "mscc,ocelot-cpu-syscon",
 101         .protect_reg     = 0x20,
 102         .vcore_protect   = BIT(2),
 103         .if_si_owner_bit = 4,
 104 };
 105
 106 static const struct reset_props reset_props_sparx5 = {
 107         .syscon          = "microchip,sparx5-cpu-syscon",
 108         .protect_reg     = 0x84,
 109         .vcore_protect   = BIT(10),
 110         .if_si_owner_bit = 6,
 111 };
 112
 113 static const struct of_device_id ocelot_reset_of_match[] = {
 114         {
 115                 .compatible = "mscc,ocelot-chip-reset",
 116                 .data = &reset_props_ocelot
 117         }, {
 118                 .compatible = "microchip,sparx5-chip-reset",
 119                 .data = &reset_props_sparx5
 120         },
 121         { /*sentinel*/ }
 122 };
 123
 124 static struct platform_driver ocelot_reset_driver = {
 125         .probe = ocelot_reset_probe,
 126         .driver = {
 127                 .name = "ocelot-chip-reset",
 128                 .of_match_table = ocelot_reset_of_match,
 129         },
 130 };
 131 builtin_platform_driver(ocelot_reset_driver);