[PATCH v2] watchdog: Add MOXA ART watchdog driver
Jonas Jensen
jonas.jensen at gmail.com
Tue Jul 16 09:24:15 EDT 2013
Add watchdog driver for MOXA ART SoCs.
Signed-off-by: Jonas Jensen <jonas.jensen at gmail.com>
---
Notes:
Thanks for the review Guenter.
Changes since v1:
1. remove moxart_wdt_ping
2. remove unnecessary max timeout check in moxart_wdt_set_timeout
3. remove arm_pm_restart and moxart_wdt_restart function
(moved to moxart platform startup code)
4. remove unnecessary watchdog_set_drvdata from moxart_wdt_remove
5. stop the watchdog on driver remove
Applies to next-20130716
drivers/watchdog/Kconfig | 10 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/moxart_wdt.c | 171 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 182 insertions(+)
create mode 100644 drivers/watchdog/moxart_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 362085d..6883aab 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -382,6 +382,16 @@ config RETU_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called retu_wdt.
+config MOXART_WDT
+ tristate "MOXART watchdog"
+ depends on ARCH_MOXART
+ help
+ Say Y here to include Watchdog timer support for the watchdog
+ existing on the MOXA ART SoC series platforms.
+
+ To compile this driver as a module, choose M here: the
+ module will be called moxart_wdt.
+
# AVR32 Architecture
config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 2f26a0b..7cab53a 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
+obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c
new file mode 100644
index 0000000..966855d
--- /dev/null
+++ b/drivers/watchdog/moxart_wdt.c
@@ -0,0 +1,171 @@
+/*
+ * MOXA ART SoCs watchdog driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen at gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#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>
+
+#include <asm/system_misc.h>
+
+#define REG_COUNT 0x4
+#define REG_MODE 0x8
+#define REG_ENABLE 0xC
+
+struct moxart_wdt_dev {
+ struct watchdog_device wdt_dev;
+ void __iomem *wdt_base;
+};
+
+static struct moxart_wdt_dev *moxart_wdt;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat;
+static unsigned int clock_frequency;
+static unsigned int max_timeout;
+
+static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = moxart_wdt->wdt_base;
+
+ writel(0, wdt_base + REG_ENABLE);
+
+ return 0;
+}
+
+static int moxart_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
+ void __iomem *wdt_base = moxart_wdt->wdt_base;
+
+ writel(clock_frequency * moxart_wdt->wdt_dev.timeout,
+ wdt_base + REG_COUNT);
+ writel(0x5ab9, wdt_base + REG_MODE);
+ writel(0x03, wdt_base + REG_ENABLE);
+
+ return 0;
+}
+
+static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ dev_dbg(wdt_dev->dev, "%s: timeout=%u\n", __func__, timeout);
+
+ moxart_wdt->wdt_dev.timeout = timeout;
+
+ return 0;
+}
+
+static const struct watchdog_info moxart_wdt_info = {
+ .identity = "moxart-wdt",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops moxart_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = moxart_wdt_start,
+ .stop = moxart_wdt_stop,
+ .set_timeout = moxart_wdt_set_timeout,
+};
+
+static int moxart_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct resource *res;
+ struct clk *clk;
+ int err;
+
+ moxart_wdt = devm_kzalloc(&pdev->dev, sizeof(*moxart_wdt), GFP_KERNEL);
+ if (!moxart_wdt)
+ return -EINVAL;
+
+ platform_set_drvdata(pdev, moxart_wdt);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ moxart_wdt->wdt_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(moxart_wdt->wdt_base))
+ return PTR_ERR(moxart_wdt->wdt_base);
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ pr_err("%s: of_clk_get failed\n", __func__);
+ return PTR_ERR(clk);
+ }
+
+ clock_frequency = clk_get_rate(clk);
+
+ max_timeout = UINT_MAX / clock_frequency;
+
+ moxart_wdt->wdt_dev.info = &moxart_wdt_info;
+ moxart_wdt->wdt_dev.ops = &moxart_wdt_ops;
+ moxart_wdt->wdt_dev.timeout = max_timeout;
+ moxart_wdt->wdt_dev.min_timeout = 1;
+ moxart_wdt->wdt_dev.max_timeout = max_timeout;
+ moxart_wdt->wdt_dev.parent = &pdev->dev;
+
+ watchdog_init_timeout(&moxart_wdt->wdt_dev, heartbeat, &pdev->dev);
+ watchdog_set_nowayout(&moxart_wdt->wdt_dev, nowayout);
+
+ watchdog_set_drvdata(&moxart_wdt->wdt_dev, moxart_wdt);
+
+ err = watchdog_register_device(&moxart_wdt->wdt_dev);
+ if (unlikely(err))
+ return err;
+
+ dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
+ moxart_wdt->wdt_dev.timeout, nowayout);
+
+ return 0;
+}
+
+static int moxart_wdt_remove(struct platform_device *pdev)
+{
+ struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
+
+ moxart_wdt_stop(&moxart_wdt->wdt_dev);
+ watchdog_unregister_device(&moxart_wdt->wdt_dev);
+
+ return 0;
+}
+
+static const struct of_device_id moxart_watchdog_match[] = {
+ { .compatible = "moxa,moxart-watchdog" },
+ { },
+};
+
+static struct platform_driver moxart_wdt_driver = {
+ .probe = moxart_wdt_probe,
+ .remove = moxart_wdt_remove,
+ .driver = {
+ .name = "moxart-watchdog",
+ .owner = THIS_MODULE,
+ .of_match_table = moxart_watchdog_match,
+ },
+};
+module_platform_driver(moxart_wdt_driver);
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
+
+MODULE_DESCRIPTION("MOXART watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen at gmail.com>");
--
1.8.2.1
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