// SPDX-License-Identifier: GPL-2.0 /* * Gemini power management controller * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> * * Inspired by code from the SL3516 board support by Jason Lee * Inspired by code from Janos Laube <janos.dev@gmail.com> */ #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm.h> #include <linux/bitops.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/reboot.h> #define GEMINI_PWC_ID 0x00010500 #define GEMINI_PWC_IDREG 0x00 #define GEMINI_PWC_CTRLREG 0x04 #define GEMINI_PWC_STATREG 0x08 #define GEMINI_CTRL_SHUTDOWN BIT(0) #define GEMINI_CTRL_ENABLE BIT(1) #define GEMINI_CTRL_IRQ_CLR BIT(2) #define GEMINI_STAT_CIR BIT(4) #define GEMINI_STAT_RTC BIT(5) #define GEMINI_STAT_POWERBUTTON BIT(6) struct gemini_powercon { struct device *dev; void __iomem *base; }; static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data) { struct gemini_powercon *gpw = data; u32 val; /* ACK the IRQ */ val = readl(gpw->base + GEMINI_PWC_CTRLREG); val |= GEMINI_CTRL_IRQ_CLR; writel(val, gpw->base + GEMINI_PWC_CTRLREG); val = readl(gpw->base + GEMINI_PWC_STATREG); val &= 0x70U; switch (val) { case GEMINI_STAT_CIR: /* * We do not yet have a driver for the infrared * controller so it can cause spurious poweroff * events. Ignore those for now. */ dev_info(gpw->dev, "infrared poweroff - ignored\n"); break; case GEMINI_STAT_RTC: dev_info(gpw->dev, "RTC poweroff\n"); orderly_poweroff(true); break; case GEMINI_STAT_POWERBUTTON: dev_info(gpw->dev, "poweroff button pressed\n"); orderly_poweroff(true); break; default: dev_info(gpw->dev, "other power management IRQ\n"); break; } return IRQ_HANDLED; } /* This callback needs this static local as it has void as argument */ static struct gemini_powercon *gpw_poweroff; static void gemini_poweroff(void) { struct gemini_powercon *gpw = gpw_poweroff; u32 val; dev_crit(gpw->dev, "Gemini power off\n"); val = readl(gpw->base + GEMINI_PWC_CTRLREG); val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR; writel(val, gpw->base + GEMINI_PWC_CTRLREG); val &= ~GEMINI_CTRL_ENABLE; val |= GEMINI_CTRL_SHUTDOWN; writel(val, gpw->base + GEMINI_PWC_CTRLREG); } static int gemini_poweroff_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct resource *res; struct gemini_powercon *gpw; u32 val; int irq; int ret; gpw = devm_kzalloc(dev, sizeof(*gpw), GFP_KERNEL); if (!gpw) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); gpw->base = devm_ioremap_resource(dev, res); if (IS_ERR(gpw->base)) return PTR_ERR(gpw->base); irq = platform_get_irq(pdev, 0); if (!irq) return -EINVAL; gpw->dev = dev; val = readl(gpw->base + GEMINI_PWC_IDREG); val &= 0xFFFFFF00U; if (val != GEMINI_PWC_ID) { dev_err(dev, "wrong power controller ID: %08x\n", val); return -ENODEV; } /* * Enable the power controller. This is crucial on Gemini * systems: if this is not done, pressing the power button * will result in unconditional poweroff without any warning. * This makes the kernel handle the poweroff. */ val = readl(gpw->base + GEMINI_PWC_CTRLREG); val |= GEMINI_CTRL_ENABLE; writel(val, gpw->base + GEMINI_PWC_CTRLREG); /* Now that the state machine is active, clear the IRQ */ val = readl(gpw->base + GEMINI_PWC_CTRLREG); val |= GEMINI_CTRL_IRQ_CLR; writel(val, gpw->base + GEMINI_PWC_CTRLREG); ret = devm_request_irq(dev, irq, gemini_powerbutton_interrupt, 0, "poweroff", gpw); if (ret) return ret; pm_power_off = gemini_poweroff; gpw_poweroff = gpw; dev_info(dev, "Gemini poweroff driver registered\n"); return 0; } static const struct of_device_id gemini_poweroff_of_match[] = { { .compatible = "cortina,gemini-power-controller", }, {} }; static struct platform_driver gemini_poweroff_driver = { .probe = gemini_poweroff_probe, .driver = { .name = "gemini-poweroff", .of_match_table = gemini_poweroff_of_match, }, }; builtin_platform_driver(gemini_poweroff_driver);