--- /dev/null
+/*
+ * sunxi Watchdog Driver
+ *
+ * Copyright (c) 2013 Carlo Caione
+ * 2012 Henrik Nordstrom
+ *
+ * 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.
+ *
+ * Based on xen_wdt.c
+ * (c) Copyright 2010 Novell, Inc.
+ */
+
+#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/notifier.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define WDT_MAX_TIMEOUT 16
+#define WDT_MIN_TIMEOUT 1
+#define WDT_TIMEOUT_MASK 0x0F
+
+#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
+
+#define WDT_MODE_EN (1 << 0)
+
+#define DRV_NAME "sunxi-wdt"
+#define DRV_VERSION "1.0"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout = WDT_MAX_TIMEOUT;
+
+/*
+ * This structure stores the register offsets for different variants
+ * of Allwinner's watchdog hardware.
+ */
+struct sunxi_wdt_reg {
+ u8 wdt_ctrl;
+ u8 wdt_cfg;
+ u8 wdt_mode;
+ u8 wdt_timeout_shift;
+ u8 wdt_reset_mask;
+ u8 wdt_reset_val;
+};
+
+struct sunxi_wdt_dev {
+ struct watchdog_device wdt_dev;
+ void __iomem *wdt_base;
+ const struct sunxi_wdt_reg *wdt_regs;
+ struct notifier_block restart_handler;
+};
+
+/*
+ * wdt_timeout_map maps the watchdog timer interval value in seconds to
+ * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3
+ *
+ * [timeout seconds] = register value
+ *
+ */
+
+static const int wdt_timeout_map[] = {
+ [1] = 0x1, /* 1s */
+ [2] = 0x2, /* 2s */
+ [3] = 0x3, /* 3s */
+ [4] = 0x4, /* 4s */
+ [5] = 0x5, /* 5s */
+ [6] = 0x6, /* 6s */
+ [8] = 0x7, /* 8s */
+ [10] = 0x8, /* 10s */
+ [12] = 0x9, /* 12s */
+ [14] = 0xA, /* 14s */
+ [16] = 0xB, /* 16s */
+};
+
+
+static int sunxi_restart_handle(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = container_of(this,
+ struct sunxi_wdt_dev,
+ restart_handler);
+ void __iomem *wdt_base = sunxi_wdt->wdt_base;
+ const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+ u32 val;
+
+ /* Set system reset function */
+ val = readl(wdt_base + regs->wdt_cfg);
+ val &= ~(regs->wdt_reset_mask);
+ val |= regs->wdt_reset_val;
+ writel(val, wdt_base + regs->wdt_cfg);
+
+ /* Set lowest timeout and enable watchdog */
+ val = readl(wdt_base + regs->wdt_mode);
+ val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
+ val |= WDT_MODE_EN;
+ writel(val, wdt_base + regs->wdt_mode);
+
+ /*
+ * Restart the watchdog. The default (and lowest) interval
+ * value for the watchdog is 0.5s.
+ */
+ writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
+
+ while (1) {
+ mdelay(5);
+ val = readl(wdt_base + regs->wdt_mode);
+ val |= WDT_MODE_EN;
+ writel(val, wdt_base + regs->wdt_mode);
+ }
+ return NOTIFY_DONE;
+}
+
+static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = sunxi_wdt->wdt_base;
+ const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+
+ writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
+
+ return 0;
+}
+
+static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = sunxi_wdt->wdt_base;
+ const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+ u32 reg;
+
+ if (wdt_timeout_map[timeout] == 0)
+ timeout++;
+
+ sunxi_wdt->wdt_dev.timeout = timeout;
+
+ reg = readl(wdt_base + regs->wdt_mode);
+ reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
+ reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
+ writel(reg, wdt_base + regs->wdt_mode);
+
+ sunxi_wdt_ping(wdt_dev);
+
+ return 0;
+}
+
+static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = sunxi_wdt->wdt_base;
+ const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+
+ writel(0, wdt_base + regs->wdt_mode);
+
+ return 0;
+}
+
+static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
+{
+ u32 reg;
+ struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = sunxi_wdt->wdt_base;
+ const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+ int ret;
+
+ ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
+ sunxi_wdt->wdt_dev.timeout);
+ if (ret < 0)
+ return ret;
+
+ /* Set system reset function */
+ reg = readl(wdt_base + regs->wdt_cfg);
+ reg &= ~(regs->wdt_reset_mask);
+ reg |= ~(regs->wdt_reset_val);
+ writel(reg, wdt_base + regs->wdt_cfg);
+
+ /* Enable watchdog */
+ reg = readl(wdt_base + regs->wdt_mode);
+ reg |= WDT_MODE_EN;
+ writel(reg, wdt_base + regs->wdt_mode);
+
+ return 0;
+}
+
+static const struct watchdog_info sunxi_wdt_info = {
+ .identity = DRV_NAME,
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops sunxi_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = sunxi_wdt_start,
+ .stop = sunxi_wdt_stop,
+ .ping = sunxi_wdt_ping,
+ .set_timeout = sunxi_wdt_set_timeout,
+};
+
+static const struct sunxi_wdt_reg sun4i_wdt_reg = {
+ .wdt_ctrl = 0x00,
+ .wdt_cfg = 0x04,
+ .wdt_mode = 0x04,
+ .wdt_timeout_shift = 3,
+ .wdt_reset_mask = 0x02,
+ .wdt_reset_val = 0x02,
+};
+
+static const struct sunxi_wdt_reg sun6i_wdt_reg = {
+ .wdt_ctrl = 0x10,
+ .wdt_cfg = 0x14,
+ .wdt_mode = 0x18,
+ .wdt_timeout_shift = 4,
+ .wdt_reset_mask = 0x03,
+ .wdt_reset_val = 0x01,
+};
+
+static const struct of_device_id sunxi_wdt_dt_ids[] = {
+ { .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
+ { .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
+
+static int sunxi_wdt_probe(struct platform_device *pdev)
+{
+ struct sunxi_wdt_dev *sunxi_wdt;
+ const struct of_device_id *device;
+ struct resource *res;
+ int err;
+
+ sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
+ if (!sunxi_wdt)
+ return -EINVAL;
+
+ platform_set_drvdata(pdev, sunxi_wdt);
+
+ device = of_match_device(sunxi_wdt_dt_ids, &pdev->dev);
+ if (!device)
+ return -ENODEV;
+
+ sunxi_wdt->wdt_regs = device->data;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(sunxi_wdt->wdt_base))
+ return PTR_ERR(sunxi_wdt->wdt_base);
+
+ sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
+ sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
+ sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
+ sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
+ sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
+ sunxi_wdt->wdt_dev.parent = &pdev->dev;
+
+ watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
+ watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
+
+ watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
+
+ sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
+
+ err = watchdog_register_device(&sunxi_wdt->wdt_dev);
+ if (unlikely(err))
+ return err;
+
+ sunxi_wdt->restart_handler.notifier_call = sunxi_restart_handle;
+ sunxi_wdt->restart_handler.priority = 128;
+ err = register_restart_handler(&sunxi_wdt->restart_handler);
+ if (err)
+ dev_err(&pdev->dev,
+ "cannot register restart handler (err=%d)\n", err);
+
+ dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
+ sunxi_wdt->wdt_dev.timeout, nowayout);
+
+ return 0;
+}
+
+static int sunxi_wdt_remove(struct platform_device *pdev)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
+
+ unregister_restart_handler(&sunxi_wdt->restart_handler);
+
+ watchdog_unregister_device(&sunxi_wdt->wdt_dev);
+ watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);
+
+ return 0;
+}
+
+static void sunxi_wdt_shutdown(struct platform_device *pdev)
+{
+ struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
+
+ sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
+}
+
+static struct platform_driver sunxi_wdt_driver = {
+ .probe = sunxi_wdt_probe,
+ .remove = sunxi_wdt_remove,
+ .shutdown = sunxi_wdt_shutdown,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = sunxi_wdt_dt_ids,
+ },
+};
+
+module_platform_driver(sunxi_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@gmail.com>");
+MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
+MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);
Code Review / kvmfornfv.git / blobdiff