diff options
Diffstat (limited to 'drivers/power/reset/gemini-poweroff.c')
| -rw-r--r-- | drivers/power/reset/gemini-poweroff.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/power/reset/gemini-poweroff.c b/drivers/power/reset/gemini-poweroff.c new file mode 100644 index 000000000..b7f7a8225 --- /dev/null +++ b/drivers/power/reset/gemini-poweroff.c @@ -0,0 +1,175 @@ +// 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 < 0) + return irq; + + 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); + + /* Clear the IRQ */ + val = readl(gpw->base + GEMINI_PWC_CTRLREG); + val |= GEMINI_CTRL_IRQ_CLR; + writel(val, gpw->base + GEMINI_PWC_CTRLREG); + + /* Wait for this to clear */ + val = readl(gpw->base + GEMINI_PWC_STATREG); + while (val & 0x70U) + val = readl(gpw->base + GEMINI_PWC_STATREG); + + /* Clear the IRQ again */ + 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); |