drivers/power/reset/gemini-poweroff.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Gemini power management controller
   4  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
   5  *
   6  * Inspired by code from the SL3516 board support by Jason Lee
   7  * Inspired by code from Janos Laube <janos.dev@gmail.com>
   8  */
   9 #include <linux/of.h>
  10 #include <linux/of_platform.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pm.h>
  13 #include <linux/bitops.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16 #include <linux/reboot.h>
  17
  18 #define GEMINI_PWC_ID           0x00010500
  19 #define GEMINI_PWC_IDREG        0x00
  20 #define GEMINI_PWC_CTRLREG      0x04
  21 #define GEMINI_PWC_STATREG      0x08
  22
  23 #define GEMINI_CTRL_SHUTDOWN    BIT(0)
  24 #define GEMINI_CTRL_ENABLE      BIT(1)
  25 #define GEMINI_CTRL_IRQ_CLR     BIT(2)
  26
  27 #define GEMINI_STAT_CIR         BIT(4)
  28 #define GEMINI_STAT_RTC         BIT(5)
  29 #define GEMINI_STAT_POWERBUTTON BIT(6)
  30
  31 struct gemini_powercon {
  32         struct device           *dev;
  33         void __iomem            *base;
  34 };
  35
  36 static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data)
  37 {
  38         struct gemini_powercon *gpw = data;
  39         u32 val;
  40
  41         /* ACK the IRQ */
  42         val = readl(gpw->base + GEMINI_PWC_CTRLREG);
  43         val |= GEMINI_CTRL_IRQ_CLR;
  44         writel(val, gpw->base + GEMINI_PWC_CTRLREG);
  45
  46         val = readl(gpw->base + GEMINI_PWC_STATREG);
  47         val &= 0x70U;
  48         switch (val) {
  49         case GEMINI_STAT_CIR:
  50                 dev_info(gpw->dev, "infrared poweroff\n");
  51                 orderly_poweroff(true);
  52                 break;
  53         case GEMINI_STAT_RTC:
  54                 dev_info(gpw->dev, "RTC poweroff\n");
  55                 orderly_poweroff(true);
  56                 break;
  57         case GEMINI_STAT_POWERBUTTON:
  58                 dev_info(gpw->dev, "poweroff button pressed\n");
  59                 orderly_poweroff(true);
  60                 break;
  61         default:
  62                 dev_info(gpw->dev, "other power management IRQ\n");
  63                 break;
  64         }
  65
  66         return IRQ_HANDLED;
  67 }
  68
  69 /* This callback needs this static local as it has void as argument */
  70 static struct gemini_powercon *gpw_poweroff;
  71
  72 static void gemini_poweroff(void)
  73 {
  74         struct gemini_powercon *gpw = gpw_poweroff;
  75         u32 val;
  76
  77         dev_crit(gpw->dev, "Gemini power off\n");
  78         val = readl(gpw->base + GEMINI_PWC_CTRLREG);
  79         val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR;
  80         writel(val, gpw->base + GEMINI_PWC_CTRLREG);
  81
  82         val &= ~GEMINI_CTRL_ENABLE;
  83         val |= GEMINI_CTRL_SHUTDOWN;
  84         writel(val, gpw->base + GEMINI_PWC_CTRLREG);
  85 }
  86
  87 static int gemini_poweroff_probe(struct platform_device *pdev)
  88 {
  89         struct device *dev = &pdev->dev;
  90         struct resource *res;
  91         struct gemini_powercon *gpw;
  92         u32 val;
  93         int irq;
  94         int ret;
  95
  96         gpw = devm_kzalloc(dev, sizeof(*gpw), GFP_KERNEL);
  97         if (!gpw)
  98                 return -ENOMEM;
  99
 100         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 101         gpw->base = devm_ioremap_resource(dev, res);
 102         if (IS_ERR(gpw->base))
 103                 return PTR_ERR(gpw->base);
 104
 105         irq = platform_get_irq(pdev, 0);
 106         if (!irq)
 107                 return -EINVAL;
 108
 109         gpw->dev = dev;
 110
 111         val = readl(gpw->base + GEMINI_PWC_IDREG);
 112         val &= 0xFFFFFF00U;
 113         if (val != GEMINI_PWC_ID) {
 114                 dev_err(dev, "wrong power controller ID: %08x\n",
 115                         val);
 116                 return -ENODEV;
 117         }
 118
 119         /* Clear the power management IRQ */
 120         val = readl(gpw->base + GEMINI_PWC_CTRLREG);
 121         val |= GEMINI_CTRL_IRQ_CLR;
 122         writel(val, gpw->base + GEMINI_PWC_CTRLREG);
 123
 124         ret = devm_request_irq(dev, irq, gemini_powerbutton_interrupt, 0,
 125                                "poweroff", gpw);
 126         if (ret)
 127                 return ret;
 128
 129         pm_power_off = gemini_poweroff;
 130         gpw_poweroff = gpw;
 131
 132         /*
 133          * Enable the power controller. This is crucial on Gemini
 134          * systems: if this is not done, pressing the power button
 135          * will result in unconditional poweroff without any warning.
 136          * This makes the kernel handle the poweroff.
 137          */
 138         val = readl(gpw->base + GEMINI_PWC_CTRLREG);
 139         val |= GEMINI_CTRL_ENABLE;
 140         writel(val, gpw->base + GEMINI_PWC_CTRLREG);
 141
 142         dev_info(dev, "Gemini poweroff driver registered\n");
 143
 144         return 0;
 145 }
 146
 147 static const struct of_device_id gemini_poweroff_of_match[] = {
 148         {
 149                 .compatible = "cortina,gemini-power-controller",
 150         },
 151         {}
 152 };
 153
 154 static struct platform_driver gemini_poweroff_driver = {
 155         .probe = gemini_poweroff_probe,
 156         .driver = {
 157                 .name = "gemini-poweroff",
 158                 .of_match_table = gemini_poweroff_of_match,
 159         },
 160 };
 161 builtin_platform_driver(gemini_poweroff_driver);