1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
new file mode 100644
index 000000000..0a6672789
--- /dev/null
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ */
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT	30	/* seconds */
+
+#define GXBB_WDT_CTRL_REG			0x0
+#define GXBB_WDT_TCNT_REG			0x8
+#define GXBB_WDT_RSET_REG			0xc
+
+#define GXBB_WDT_CTRL_CLKDIV_EN			BIT(25)
+#define GXBB_WDT_CTRL_CLK_EN			BIT(24)
+#define GXBB_WDT_CTRL_EE_RESET			BIT(21)
+#define GXBB_WDT_CTRL_EN			BIT(18)
+#define GXBB_WDT_CTRL_DIV_MASK			(BIT(18) - 1)
+
+#define GXBB_WDT_TCNT_SETUP_MASK		(BIT(16) - 1)
+#define GXBB_WDT_TCNT_CNT_SHIFT			16
+
+struct meson_gxbb_wdt {
+	void __iomem *reg_base;
+	struct watchdog_device wdt_dev;
+	struct clk *clk;
+};
+
+static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
+	       data->reg_base + GXBB_WDT_CTRL_REG);
+
+	return 0;
+}
+
+static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
+	       data->reg_base + GXBB_WDT_CTRL_REG);
+
+	return 0;
+}
+
+static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+	writel(0, data->reg_base + GXBB_WDT_RSET_REG);
+
+	return 0;
+}
+
+static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
+				      unsigned int timeout)
+{
+	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+	unsigned long tcnt = timeout * 1000;
+
+	if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
+		tcnt = GXBB_WDT_TCNT_SETUP_MASK;
+
+	wdt_dev->timeout = timeout;
+
+	meson_gxbb_wdt_ping(wdt_dev);
+
+	writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
+
+	return 0;
+}
+
+static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
+{
+	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+	unsigned long reg;
+
+	reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
+
+	return ((reg & GXBB_WDT_TCNT_SETUP_MASK) -
+		(reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000;
+}
+
+static const struct watchdog_ops meson_gxbb_wdt_ops = {
+	.start = meson_gxbb_wdt_start,
+	.stop = meson_gxbb_wdt_stop,
+	.ping = meson_gxbb_wdt_ping,
+	.set_timeout = meson_gxbb_wdt_set_timeout,
+	.get_timeleft = meson_gxbb_wdt_get_timeleft,
+};
+
+static const struct watchdog_info meson_gxbb_wdt_info = {
+	.identity = "Meson GXBB Watchdog",
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
+{
+	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
+
+	if (watchdog_active(&data->wdt_dev))
+		meson_gxbb_wdt_start(&data->wdt_dev);
+
+	return 0;
+}
+
+static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
+{
+	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
+
+	if (watchdog_active(&data->wdt_dev))
+		meson_gxbb_wdt_stop(&data->wdt_dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
+};
+
+static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
+	 { .compatible = "amlogic,meson-gxbb-wdt", },
+	 { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
+
+static int meson_gxbb_wdt_probe(struct platform_device *pdev)
+{
+	struct meson_gxbb_wdt *data;
+	struct resource *res;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->reg_base))
+		return PTR_ERR(data->reg_base);
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(data->clk))
+		return PTR_ERR(data->clk);
+
+	ret = clk_prepare_enable(data->clk);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, data);
+
+	data->wdt_dev.parent = &pdev->dev;
+	data->wdt_dev.info = &meson_gxbb_wdt_info;
+	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
+	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
+	data->wdt_dev.min_timeout = 1;
+	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
+	watchdog_set_drvdata(&data->wdt_dev, data);
+
+	/* Setup with 1ms timebase */
+	writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
+		GXBB_WDT_CTRL_EE_RESET |
+		GXBB_WDT_CTRL_CLK_EN |
+		GXBB_WDT_CTRL_CLKDIV_EN,
+		data->reg_base + GXBB_WDT_CTRL_REG);
+
+	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
+
+	ret = watchdog_register_device(&data->wdt_dev);
+	if (ret) {
+		clk_disable_unprepare(data->clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int meson_gxbb_wdt_remove(struct platform_device *pdev)
+{
+	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
+
+	watchdog_unregister_device(&data->wdt_dev);
+
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
+{
+	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
+
+	meson_gxbb_wdt_stop(&data->wdt_dev);
+}
+
+static struct platform_driver meson_gxbb_wdt_driver = {
+	.probe	= meson_gxbb_wdt_probe,
+	.remove	= meson_gxbb_wdt_remove,
+	.shutdown = meson_gxbb_wdt_shutdown,
+	.driver = {
+		.name = "meson-gxbb-wdt",
+		.pm = &meson_gxbb_wdt_pm_ops,
+		.of_match_table	= meson_gxbb_wdt_dt_ids,
+	},
+};
+
+module_platform_driver(meson_gxbb_wdt_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
+MODULE_LICENSE("Dual BSD/GPL");