[PATCH] ARM: sunxi: New watchdog driver for Allwinner A10/A13
Carlo Caione
carlo.caione at gmail.com
Sun May 12 16:36:34 EDT 2013
This patch adds the driver for the watchdog found in the Allwinner A10 and
A13 SoCs. It has DT-support and uses the new watchdog framework.
Signed-off-by: Carlo Caione <carlo.caione at gmail.com>
---
drivers/watchdog/Kconfig | 10 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/sunxi_wdt.c | 218 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 229 insertions(+)
create mode 100644 drivers/watchdog/sunxi_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index e89fc31..473e670 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -299,6 +299,16 @@ config ORION_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called orion_wdt.
+config SUNXI_WATCHDOG
+ tristate "Sunxi watchdog"
+ depends on ARCH_SUNXI
+ select WATCHDOG_CORE
+ help
+ Say Y here to include support for the watchdog timer
+ in Allwinner A10 and A13.
+ To compile this driver as a module, choose M here: the
+ module will be called sunxi_wdt.
+
config COH901327_WATCHDOG
bool "ST-Ericsson COH 901 327 watchdog"
depends on ARCH_U300
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index a300b94..5012d5f 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
+obj-$(CONFIG_SUNXI_WATCHDOG) += sunxi_wdt.o
obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
new file mode 100644
index 0000000..fe193b3
--- /dev/null
+++ b/drivers/watchdog/sunxi_wdt.c
@@ -0,0 +1,218 @@
+/*
+ * 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/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_address.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define WDT_MAX_TIMEOUT 16
+#define WDT_MIN_TIMEOUT 1
+#define WDT_MODE_TIMEOUT(n) ((n) << 3)
+#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
+
+#define WDT_CTRL 0x00
+#define WDT_MODE 0x04
+
+#define WDT_MODE_RST_EN (1 << 1)
+#define WDT_MODE_EN (1 << 0)
+
+#define WDT_CTRL_RESTART (1 << 0)
+#define WDT_CTRL_RESERVED (0x0a57 << 1)
+#define DRV_NAME "sunxi-wdt"
+#define DRV_VERSION "1.0"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat = WDT_MAX_TIMEOUT;
+
+static const int wdt_timeout_map[] = {
+ [1] = 0b0001,
+ [2] = 0b0010,
+ [3] = 0b0011,
+ [4] = 0b0100,
+ [5] = 0b0101,
+ [6] = 0b0110,
+ [8] = 0b0111,
+ [10] = 0b1000,
+ [12] = 0b1001,
+ [14] = 0b1010,
+ [16] = 0b1011,
+};
+
+static int sunxi_wdt_ping(struct watchdog_device *sunxi_wdt_dev)
+{
+ u32 reg;
+ void __iomem *wdt_base = watchdog_get_drvdata(sunxi_wdt_dev);
+
+ reg = ioread32(wdt_base + WDT_CTRL);
+ reg |= (WDT_CTRL_RESTART | WDT_CTRL_RESERVED);
+ iowrite32(reg, wdt_base + WDT_CTRL);
+
+ return 0;
+}
+
+static int sunxi_wdt_set_timeout(struct watchdog_device *sunxi_wdt_dev,
+ unsigned int timeout)
+{
+ u32 reg;
+ void __iomem *wdt_base = watchdog_get_drvdata(sunxi_wdt_dev);
+
+ if ((timeout > WDT_MAX_TIMEOUT) || (0 == wdt_timeout_map[timeout]))
+ return -EINVAL;
+
+ sunxi_wdt_dev->timeout = timeout;
+
+ reg = ioread32(wdt_base + WDT_MODE);
+ reg &= ~(WDT_TIMEOUT_MASK);
+ reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[sunxi_wdt_dev->timeout]);
+ iowrite32(reg, wdt_base + WDT_MODE);
+
+ sunxi_wdt_ping(sunxi_wdt_dev);
+
+ return 0;
+}
+
+static int sunxi_wdt_stop(struct watchdog_device *sunxi_wdt_dev)
+{
+ u32 reg;
+ void __iomem *wdt_base = watchdog_get_drvdata(sunxi_wdt_dev);
+
+ reg = ioread32(wdt_base + WDT_MODE);
+ reg &= ~(WDT_MODE_RST_EN | WDT_MODE_EN);
+ iowrite32(reg, wdt_base + WDT_MODE);
+
+ return 0;
+}
+
+static int sunxi_wdt_start(struct watchdog_device *sunxi_wdt_dev)
+{
+ u32 reg;
+ int ret;
+ void __iomem *wdt_base = watchdog_get_drvdata(sunxi_wdt_dev);
+
+ ret = sunxi_wdt_set_timeout(sunxi_wdt_dev, sunxi_wdt_dev->timeout);
+ if (ret < 0)
+ return ret;
+
+ reg = ioread32(wdt_base + WDT_MODE);
+ reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);
+ iowrite32(reg, wdt_base + 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 struct watchdog_device sunxi_wdt_dev = {
+ .info = &sunxi_wdt_info,
+ .ops = &sunxi_wdt_ops,
+ .timeout = WDT_MAX_TIMEOUT,
+ .max_timeout = WDT_MAX_TIMEOUT,
+ .min_timeout = WDT_MIN_TIMEOUT,
+};
+
+static int __init sunxi_wdt_probe(struct platform_device *pdev)
+{
+ int err;
+ void __iomem *wdt_base;
+
+ wdt_base = of_iomap(pdev->dev.of_node, 0);
+ if (unlikely(!wdt_base)) {
+ err = -ENOMEM;
+ goto error_mem_out;
+ }
+
+ sunxi_wdt_dev.parent = &pdev->dev;
+ watchdog_init_timeout(&sunxi_wdt_dev, heartbeat, &pdev->dev);
+ watchdog_set_nowayout(&sunxi_wdt_dev, nowayout);
+
+ err = watchdog_register_device(&sunxi_wdt_dev);
+ if (unlikely(err))
+ goto error_wdt;
+
+ watchdog_set_drvdata(&sunxi_wdt_dev, wdt_base);
+
+ pr_info("Watchdog enabled (heartbeat=%d sec, nowayout=%d)",
+ sunxi_wdt_dev.timeout, nowayout);
+ return 0;
+
+error_wdt:
+ iounmap(wdt_base);
+error_mem_out:
+ return err;
+}
+
+static int __exit sunxi_wdt_remove(struct platform_device *pdev)
+{
+ void __iomem *wdt_base = watchdog_get_drvdata(&sunxi_wdt_dev);
+
+ sunxi_wdt_stop(&sunxi_wdt_dev);
+ watchdog_unregister_device(&sunxi_wdt_dev);
+ iounmap(wdt_base);
+
+ return 0;
+}
+
+static const struct of_device_id sunxi_wdt_dt_ids[] = {
+ { .compatible = "allwinner,sun4i-wdt" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
+
+static struct platform_driver sunxi_wdt_driver = {
+ .probe = sunxi_wdt_probe,
+ .remove = sunxi_wdt_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ .of_match_table = of_match_ptr(sunxi_wdt_dt_ids)
+ },
+};
+
+module_platform_driver(sunxi_wdt_driver);
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "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 at gmail.com>");
+MODULE_AUTHOR("Henrik Nordstrom <henrik at henriknordstrom.net>");
+MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);
--
1.8.2.3
More information about the linux-arm-kernel
mailing list