--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Loongson-2 PM Support
+ *
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/suspend.h>
+#include <linux/interrupt.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/platform_device.h>
+#include <asm/bootinfo.h>
+#include <asm/suspend.h>
+
+#define LOONGSON2_PM1_CNT_REG 0x14
+#define LOONGSON2_PM1_STS_REG 0x0c
+#define LOONGSON2_PM1_ENA_REG 0x10
+#define LOONGSON2_GPE0_STS_REG 0x28
+#define LOONGSON2_GPE0_ENA_REG 0x2c
+
+#define LOONGSON2_PM1_PWRBTN_STS BIT(8)
+#define LOONGSON2_PM1_PCIEXP_WAKE_STS BIT(14)
+#define LOONGSON2_PM1_WAKE_STS BIT(15)
+#define LOONGSON2_PM1_CNT_INT_EN BIT(0)
+#define LOONGSON2_PM1_PWRBTN_EN LOONGSON2_PM1_PWRBTN_STS
+
+static struct loongson2_pm {
+ void __iomem *base;
+ struct input_dev *dev;
+ bool suspended;
+} loongson2_pm;
+
+#define loongson2_pm_readw(reg) readw(loongson2_pm.base + reg)
+#define loongson2_pm_readl(reg) readl(loongson2_pm.base + reg)
+#define loongson2_pm_writew(val, reg) writew(val, loongson2_pm.base + reg)
+#define loongson2_pm_writel(val, reg) writel(val, loongson2_pm.base + reg)
+
+static void loongson2_pm_status_clear(void)
+{
+ u16 value;
+
+ value = loongson2_pm_readw(LOONGSON2_PM1_STS_REG);
+ value |= (LOONGSON2_PM1_PWRBTN_STS | LOONGSON2_PM1_PCIEXP_WAKE_STS |
+ LOONGSON2_PM1_WAKE_STS);
+ loongson2_pm_writew(value, LOONGSON2_PM1_STS_REG);
+ loongson2_pm_writel(loongson2_pm_readl(LOONGSON2_GPE0_STS_REG), LOONGSON2_GPE0_STS_REG);
+}
+
+static void loongson2_pm_irq_enable(void)
+{
+ u16 value;
+
+ value = loongson2_pm_readw(LOONGSON2_PM1_CNT_REG);
+ value |= LOONGSON2_PM1_CNT_INT_EN;
+ loongson2_pm_writew(value, LOONGSON2_PM1_CNT_REG);
+
+ value = loongson2_pm_readw(LOONGSON2_PM1_ENA_REG);
+ value |= LOONGSON2_PM1_PWRBTN_EN;
+ loongson2_pm_writew(value, LOONGSON2_PM1_ENA_REG);
+}
+
+static int loongson2_suspend_enter(suspend_state_t state)
+{
+ loongson2_pm_status_clear();
+ loongarch_common_suspend();
+ loongarch_suspend_enter();
+ loongarch_common_resume();
+ loongson2_pm_irq_enable();
+ pm_set_resume_via_firmware();
+
+ return 0;
+}
+
+static int loongson2_suspend_begin(suspend_state_t state)
+{
+ pm_set_suspend_via_firmware();
+
+ return 0;
+}
+
+static int loongson2_suspend_valid_state(suspend_state_t state)
+{
+ return (state == PM_SUSPEND_MEM);
+}
+
+static const struct platform_suspend_ops loongson2_suspend_ops = {
+ .valid = loongson2_suspend_valid_state,
+ .begin = loongson2_suspend_begin,
+ .enter = loongson2_suspend_enter,
+};
+
+static int loongson2_power_button_init(struct device *dev, int irq)
+{
+ int ret;
+ struct input_dev *button;
+
+ button = input_allocate_device();
+ if (!dev)
+ return -ENOMEM;
+
+ button->name = "Power Button";
+ button->phys = "pm/button/input0";
+ button->id.bustype = BUS_HOST;
+ button->dev.parent = NULL;
+ input_set_capability(button, EV_KEY, KEY_POWER);
+
+ ret = input_register_device(button);
+ if (ret)
+ goto free_dev;
+
+ dev_pm_set_wake_irq(&button->dev, irq);
+ device_set_wakeup_capable(&button->dev, true);
+ device_set_wakeup_enable(&button->dev, true);
+
+ loongson2_pm.dev = button;
+ dev_info(dev, "Power Button: Init successful!\n");
+
+ return 0;
+
+free_dev:
+ input_free_device(button);
+
+ return ret;
+}
+
+static irqreturn_t loongson2_pm_irq_handler(int irq, void *dev_id)
+{
+ u16 status = loongson2_pm_readw(LOONGSON2_PM1_STS_REG);
+
+ if (!loongson2_pm.suspended && (status & LOONGSON2_PM1_PWRBTN_STS)) {
+ pr_info("Power Button pressed...\n");
+ input_report_key(loongson2_pm.dev, KEY_POWER, 1);
+ input_sync(loongson2_pm.dev);
+ input_report_key(loongson2_pm.dev, KEY_POWER, 0);
+ input_sync(loongson2_pm.dev);
+ }
+
+ loongson2_pm_status_clear();
+
+ return IRQ_HANDLED;
+}
+
+static int __maybe_unused loongson2_pm_suspend(struct device *dev)
+{
+ loongson2_pm.suspended = true;
+
+ return 0;
+}
+
+static int __maybe_unused loongson2_pm_resume(struct device *dev)
+{
+ loongson2_pm.suspended = false;
+
+ return 0;
+}
+static SIMPLE_DEV_PM_OPS(loongson2_pm_ops, loongson2_pm_suspend, loongson2_pm_resume);
+
+static int loongson2_pm_probe(struct platform_device *pdev)
+{
+ int irq, retval;
+ u64 suspend_addr;
+ struct device *dev = &pdev->dev;
+
+ loongson2_pm.base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(loongson2_pm.base))
+ return PTR_ERR(loongson2_pm.base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ if (!device_property_read_u64(dev, "loongson,suspend-address", &suspend_addr))
+ loongson_sysconf.suspend_addr = (u64)phys_to_virt(suspend_addr);
+ else
+ dev_err(dev, "No loongson,suspend-address, could not support S3!\n");
+
+ if (loongson2_power_button_init(dev, irq))
+ return -EINVAL;
+
+ retval = devm_request_irq(&pdev->dev, irq, loongson2_pm_irq_handler,
+ IRQF_SHARED, "pm_irq", &loongson2_pm);
+ if (retval)
+ return retval;
+
+ loongson2_pm_irq_enable();
+ loongson2_pm_status_clear();
+
+ if (loongson_sysconf.suspend_addr)
+ suspend_set_ops(&loongson2_suspend_ops);
+
+ return 0;
+}
+
+static const struct of_device_id loongson2_pm_match[] = {
+ { .compatible = "loongson,ls2k0500-pmc", },
+ { .compatible = "loongson,ls2k1000-pmc", },
+ {},
+};
+
+static struct platform_driver loongson2_pm_driver = {
+ .driver = {
+ .name = "ls2k-pm",
+ .pm = &loongson2_pm_ops,
+ .of_match_table = loongson2_pm_match,
+ },
+ .probe = loongson2_pm_probe,
+};
+module_platform_driver(loongson2_pm_driver);
+
+MODULE_DESCRIPTION("Loongson-2 PM driver");
+MODULE_LICENSE("GPL");
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