Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / watchdog / txx9wdt.c

diff --git a/kernel/drivers/watchdog/txx9wdt.c b/kernel/drivers/watchdog/txx9wdt.c
new file mode 100644 (file)
index 0000000..7f61593
--- /dev/null
+++ b/kernel/drivers/watchdog/txx9wdt.c
@@ -0,0 +1,177 @@
+/*
+ * txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs
+ *
+ * Copyright (C) 2007 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <asm/txx9tmr.h>
+
+#define WD_TIMER_CCD   7               /* 1/256 */
+#define WD_TIMER_CLK   (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
+#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)
+#define TIMER_MARGIN   60              /* Default is 60 seconds */
+
+static unsigned int timeout = TIMER_MARGIN;    /* in seconds */
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+       "Watchdog timeout in seconds. "
+       "(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), "
+       "default=" __MODULE_STRING(TIMER_MARGIN) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+       "Watchdog cannot be stopped once started "
+       "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static struct txx9_tmr_reg __iomem *txx9wdt_reg;
+static struct clk *txx9_imclk;
+static DEFINE_SPINLOCK(txx9_lock);
+
+static int txx9wdt_ping(struct watchdog_device *wdt_dev)
+{
+       spin_lock(&txx9_lock);
+       __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
+       spin_unlock(&txx9_lock);
+       return 0;
+}
+
+static int txx9wdt_start(struct watchdog_device *wdt_dev)
+{
+       spin_lock(&txx9_lock);
+       __raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra);
+       __raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr);
+       __raw_writel(0, &txx9wdt_reg->tisr);    /* clear pending interrupt */
+       __raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG,
+                    &txx9wdt_reg->tcr);
+       __raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
+       spin_unlock(&txx9_lock);
+       return 0;
+}
+
+static int txx9wdt_stop(struct watchdog_device *wdt_dev)
+{
+       spin_lock(&txx9_lock);
+       __raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
+       __raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
+                    &txx9wdt_reg->tcr);
+       spin_unlock(&txx9_lock);
+       return 0;
+}
+
+static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
+                              unsigned int new_timeout)
+{
+       wdt_dev->timeout = new_timeout;
+       txx9wdt_stop(wdt_dev);
+       txx9wdt_start(wdt_dev);
+       return 0;
+}
+
+static const struct watchdog_info txx9wdt_info = {
+       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+       .identity = "Hardware Watchdog for TXx9",
+};
+
+static const struct watchdog_ops txx9wdt_ops = {
+       .owner = THIS_MODULE,
+       .start = txx9wdt_start,
+       .stop = txx9wdt_stop,
+       .ping = txx9wdt_ping,
+       .set_timeout = txx9wdt_set_timeout,
+};
+
+static struct watchdog_device txx9wdt = {
+       .info = &txx9wdt_info,
+       .ops = &txx9wdt_ops,
+};
+
+static int __init txx9wdt_probe(struct platform_device *dev)
+{
+       struct resource *res;
+       int ret;
+
+       txx9_imclk = clk_get(NULL, "imbus_clk");
+       if (IS_ERR(txx9_imclk)) {
+               ret = PTR_ERR(txx9_imclk);
+               txx9_imclk = NULL;
+               goto exit;
+       }
+       ret = clk_enable(txx9_imclk);
+       if (ret) {
+               clk_put(txx9_imclk);
+               txx9_imclk = NULL;
+               goto exit;
+       }
+
+       res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+       txx9wdt_reg = devm_ioremap_resource(&dev->dev, res);
+       if (IS_ERR(txx9wdt_reg)) {
+               ret = PTR_ERR(txx9wdt_reg);
+               goto exit;
+       }
+
+       if (timeout < 1 || timeout > WD_MAX_TIMEOUT)
+               timeout = TIMER_MARGIN;
+       txx9wdt.timeout = timeout;
+       txx9wdt.min_timeout = 1;
+       txx9wdt.max_timeout = WD_MAX_TIMEOUT;
+       watchdog_set_nowayout(&txx9wdt, nowayout);
+
+       ret = watchdog_register_device(&txx9wdt);
+       if (ret)
+               goto exit;
+
+       pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
+               timeout, WD_MAX_TIMEOUT, nowayout);
+
+       return 0;
+exit:
+       if (txx9_imclk) {
+               clk_disable(txx9_imclk);
+               clk_put(txx9_imclk);
+       }
+       return ret;
+}
+
+static int __exit txx9wdt_remove(struct platform_device *dev)
+{
+       watchdog_unregister_device(&txx9wdt);
+       clk_disable(txx9_imclk);
+       clk_put(txx9_imclk);
+       return 0;
+}
+
+static void txx9wdt_shutdown(struct platform_device *dev)
+{
+       txx9wdt_stop(&txx9wdt);
+}
+
+static struct platform_driver txx9wdt_driver = {
+       .remove = __exit_p(txx9wdt_remove),
+       .shutdown = txx9wdt_shutdown,
+       .driver = {
+               .name = "txx9wdt",
+       },
+};
+
+module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe);
+
+MODULE_DESCRIPTION("TXx9 Watchdog Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:txx9wdt");