[2/4] power: reset: Add a driver for the Gemini poweroff

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index abeb77217a21..0d2c4183d0ff 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -67,6 +67,15 @@  config POWER_RESET_BRCMSTB
 	  Say Y here if you have a Broadcom STB board and you wish
 	  to have restart support.
 
+config POWER_RESET_GEMINI_POWEROFF
+	bool "Cortina Gemini power-off driver"
+	depends on ARCH_GEMINI || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	default ARCH_GEMINI
+	help
+	  This driver supports turning off the Cortina Gemini SoC.
+	  Select this if you're building a kernel with Gemini SoC support.
+
 config POWER_RESET_GPIO
 	bool "GPIO power-off driver"
 	depends on OF_GPIO
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 11dae3b56ff9..58cf5b30559f 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -5,6 +5,7 @@  obj-$(CONFIG_POWER_RESET_AT91_SAMA5D2_SHDWC) += at91-sama5d2_shdwc.o
 obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
 obj-$(CONFIG_POWER_RESET_BRCMKONA) += brcm-kona-reset.o
 obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
+obj-$(CONFIG_POWER_RESET_GEMINI_POWEROFF) += gemini-poweroff.o
 obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
 obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
 obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
diff --git a/drivers/power/reset/gemini-poweroff.c b/drivers/power/reset/gemini-poweroff.c
new file mode 100644
index 000000000000..de878fd26f27
--- /dev/null
+++ b/drivers/power/reset/gemini-poweroff.c
@@ -0,0 +1,160 @@ 
+/*
+ * 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:
+		dev_info(gpw->dev, "infrared poweroff\n");
+		orderly_poweroff(true);
+		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;
+	}
+
+	/* Clear the power management 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;
+
+	/*
+	 * 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);
+
+	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);