v4.19.13 snapshot.
diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c
new file mode 100644
index 0000000..cd0275a
--- /dev/null
+++ b/drivers/watchdog/meson_wdt.c
@@ -0,0 +1,237 @@
+/*
+ * Meson Watchdog Driver
+ *
+ * Copyright (c) 2014 Carlo Caione
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define DRV_NAME "meson_wdt"
+
+#define MESON_WDT_TC 0x00
+#define MESON_WDT_DC_RESET (3 << 24)
+
+#define MESON_WDT_RESET 0x04
+
+#define MESON_WDT_TIMEOUT 30
+#define MESON_WDT_MIN_TIMEOUT 1
+
+#define MESON_SEC_TO_TC(s, c) ((s) * (c))
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout;
+
+struct meson_wdt_data {
+ unsigned int enable;
+ unsigned int terminal_count_mask;
+ unsigned int count_unit;
+};
+
+static struct meson_wdt_data meson6_wdt_data = {
+ .enable = BIT(22),
+ .terminal_count_mask = 0x3fffff,
+ .count_unit = 100000, /* 10 us */
+};
+
+static struct meson_wdt_data meson8b_wdt_data = {
+ .enable = BIT(19),
+ .terminal_count_mask = 0xffff,
+ .count_unit = 7812, /* 128 us */
+};
+
+struct meson_wdt_dev {
+ struct watchdog_device wdt_dev;
+ void __iomem *wdt_base;
+ const struct meson_wdt_data *data;
+};
+
+static int meson_wdt_restart(struct watchdog_device *wdt_dev,
+ unsigned long action, void *data)
+{
+ struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+ u32 tc_reboot = MESON_WDT_DC_RESET;
+
+ tc_reboot |= meson_wdt->data->enable;
+
+ while (1) {
+ writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
+ mdelay(5);
+ }
+
+ return 0;
+}
+
+static int meson_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+
+ writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
+
+ return 0;
+}
+
+static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+ u32 reg;
+
+ reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
+ reg &= ~meson_wdt->data->terminal_count_mask;
+ reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
+ writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
+}
+
+static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ wdt_dev->timeout = timeout;
+
+ meson_wdt_change_timeout(wdt_dev, timeout);
+ meson_wdt_ping(wdt_dev);
+
+ return 0;
+}
+
+static int meson_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+ u32 reg;
+
+ reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
+ reg &= ~meson_wdt->data->enable;
+ writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
+
+ return 0;
+}
+
+static int meson_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+ u32 reg;
+
+ meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
+ meson_wdt_ping(wdt_dev);
+
+ reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
+ reg |= meson_wdt->data->enable;
+ writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
+
+ return 0;
+}
+
+static const struct watchdog_info meson_wdt_info = {
+ .identity = DRV_NAME,
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops meson_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = meson_wdt_start,
+ .stop = meson_wdt_stop,
+ .ping = meson_wdt_ping,
+ .set_timeout = meson_wdt_set_timeout,
+ .restart = meson_wdt_restart,
+};
+
+static const struct of_device_id meson_wdt_dt_ids[] = {
+ { .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
+ { .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
+ { .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
+ { .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
+
+static int meson_wdt_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct meson_wdt_dev *meson_wdt;
+ const struct of_device_id *of_id;
+ int err;
+
+ meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
+ if (!meson_wdt)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(meson_wdt->wdt_base))
+ return PTR_ERR(meson_wdt->wdt_base);
+
+ of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
+ if (!of_id) {
+ dev_err(&pdev->dev, "Unable to initialize WDT data\n");
+ return -ENODEV;
+ }
+ meson_wdt->data = of_id->data;
+
+ meson_wdt->wdt_dev.parent = &pdev->dev;
+ meson_wdt->wdt_dev.info = &meson_wdt_info;
+ meson_wdt->wdt_dev.ops = &meson_wdt_ops;
+ meson_wdt->wdt_dev.max_timeout =
+ meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
+ meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
+ meson_wdt->wdt_dev.timeout = min_t(unsigned int,
+ MESON_WDT_TIMEOUT,
+ meson_wdt->wdt_dev.max_timeout);
+
+ watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
+
+ watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev);
+ watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
+ watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
+
+ meson_wdt_stop(&meson_wdt->wdt_dev);
+
+ watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
+ err = devm_watchdog_register_device(&pdev->dev, &meson_wdt->wdt_dev);
+ if (err)
+ return err;
+
+ dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
+ meson_wdt->wdt_dev.timeout, nowayout);
+
+ return 0;
+}
+
+static struct platform_driver meson_wdt_driver = {
+ .probe = meson_wdt_probe,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = meson_wdt_dt_ids,
+ },
+};
+
+module_platform_driver(meson_wdt_driver);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_DESCRIPTION("Meson Watchdog Timer Driver");