drivers/soc/tegra/pmc-tegra186.c

   1 /*
   2  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  */
  13
  14 #define pr_fmt(fmt) "tegra-pmc: " fmt
  15
  16 #include <linux/io.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/reboot.h>
  21
  22 #include <asm/system_misc.h>
  23
  24 #define PMC_CNTRL 0x000
  25 #define  PMC_CNTRL_MAIN_RST BIT(4)
  26
  27 #define PMC_RST_STATUS 0x070
  28
  29 #define WAKE_AOWAKE_CTRL 0x4f4
  30 #define  WAKE_AOWAKE_CTRL_INTR_POLARITY BIT(0)
  31
  32 #define SCRATCH_SCRATCH0 0x2000
  33 #define  SCRATCH_SCRATCH0_MODE_RECOVERY BIT(31)
  34 #define  SCRATCH_SCRATCH0_MODE_BOOTLOADER BIT(30)
  35 #define  SCRATCH_SCRATCH0_MODE_RCM BIT(1)
  36 #define  SCRATCH_SCRATCH0_MODE_MASK (SCRATCH_SCRATCH0_MODE_RECOVERY | \
  37                                      SCRATCH_SCRATCH0_MODE_BOOTLOADER | \
  38                                      SCRATCH_SCRATCH0_MODE_RCM)
  39
  40 struct tegra_pmc {
  41         struct device *dev;
  42         void __iomem *regs;
  43         void __iomem *wake;
  44         void __iomem *aotag;
  45         void __iomem *scratch;
  46
  47         void (*system_restart)(enum reboot_mode mode, const char *cmd);
  48         struct notifier_block restart;
  49 };
  50
  51 static int tegra186_pmc_restart_notify(struct notifier_block *nb,
  52                                        unsigned long action,
  53                                        void *data)
  54 {
  55         struct tegra_pmc *pmc = container_of(nb, struct tegra_pmc, restart);
  56         const char *cmd = data;
  57         u32 value;
  58
  59         value = readl(pmc->scratch + SCRATCH_SCRATCH0);
  60         value &= ~SCRATCH_SCRATCH0_MODE_MASK;
  61
  62         if (cmd) {
  63                 if (strcmp(cmd, "recovery") == 0)
  64                         value |= SCRATCH_SCRATCH0_MODE_RECOVERY;
  65
  66                 if (strcmp(cmd, "bootloader") == 0)
  67                         value |= SCRATCH_SCRATCH0_MODE_BOOTLOADER;
  68
  69                 if (strcmp(cmd, "forced-recovery") == 0)
  70                         value |= SCRATCH_SCRATCH0_MODE_RCM;
  71         }
  72
  73         writel(value, pmc->scratch + SCRATCH_SCRATCH0);
  74
  75         /*
  76          * If available, call the system restart implementation that was
  77          * registered earlier (typically PSCI).
  78          */
  79         if (pmc->system_restart) {
  80                 pmc->system_restart(reboot_mode, cmd);
  81                 return NOTIFY_DONE;
  82         }
  83
  84         /* reset everything but SCRATCH0_SCRATCH0 and PMC_RST_STATUS */
  85         value = readl(pmc->regs + PMC_CNTRL);
  86         value |= PMC_CNTRL_MAIN_RST;
  87         writel(value, pmc->regs + PMC_CNTRL);
  88
  89         return NOTIFY_DONE;
  90 }
  91
  92 static int tegra186_pmc_setup(struct tegra_pmc *pmc)
  93 {
  94         struct device_node *np = pmc->dev->of_node;
  95         bool invert;
  96         u32 value;
  97
  98         invert = of_property_read_bool(np, "nvidia,invert-interrupt");
  99
 100         value = readl(pmc->wake + WAKE_AOWAKE_CTRL);
 101
 102         if (invert)
 103                 value |= WAKE_AOWAKE_CTRL_INTR_POLARITY;
 104         else
 105                 value &= ~WAKE_AOWAKE_CTRL_INTR_POLARITY;
 106
 107         writel(value, pmc->wake + WAKE_AOWAKE_CTRL);
 108
 109         /*
 110          * We need to hook any system restart implementation registered
 111          * previously so we can write SCRATCH_SCRATCH0 before reset.
 112          */
 113         pmc->system_restart = arm_pm_restart;
 114         arm_pm_restart = NULL;
 115
 116         pmc->restart.notifier_call = tegra186_pmc_restart_notify;
 117         pmc->restart.priority = 128;
 118
 119         return register_restart_handler(&pmc->restart);
 120 }
 121
 122 static int tegra186_pmc_probe(struct platform_device *pdev)
 123 {
 124         struct tegra_pmc *pmc;
 125         struct resource *res;
 126
 127         pmc = devm_kzalloc(&pdev->dev, sizeof(*pmc), GFP_KERNEL);
 128         if (!pmc)
 129                 return -ENOMEM;
 130
 131         pmc->dev = &pdev->dev;
 132
 133         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pmc");
 134         pmc->regs = devm_ioremap_resource(&pdev->dev, res);
 135         if (IS_ERR(pmc->regs))
 136                 return PTR_ERR(pmc->regs);
 137
 138         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "wake");
 139         pmc->wake = devm_ioremap_resource(&pdev->dev, res);
 140         if (IS_ERR(pmc->wake))
 141                 return PTR_ERR(pmc->wake);
 142
 143         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "aotag");
 144         pmc->aotag = devm_ioremap_resource(&pdev->dev, res);
 145         if (IS_ERR(pmc->aotag))
 146                 return PTR_ERR(pmc->aotag);
 147
 148         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "scratch");
 149         pmc->scratch = devm_ioremap_resource(&pdev->dev, res);
 150         if (IS_ERR(pmc->scratch))
 151                 return PTR_ERR(pmc->scratch);
 152
 153         return tegra186_pmc_setup(pmc);
 154 }
 155
 156 static const struct of_device_id tegra186_pmc_of_match[] = {
 157         { .compatible = "nvidia,tegra186-pmc" },
 158         { /* sentinel */ }
 159 };
 160 MODULE_DEVICE_TABLE(of, tegra186_pmc_of_match);
 161
 162 static struct platform_driver tegra186_pmc_driver = {
 163         .driver = {
 164                 .name = "tegra186-pmc",
 165                 .of_match_table = tegra186_pmc_of_match,
 166         },
 167         .probe = tegra186_pmc_probe,
 168 };
 169 builtin_platform_driver(tegra186_pmc_driver);