4 files changed, 220 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index cbd5ac7b8832..c845527b503a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -665,6 +665,19 @@ config INTEL_SCU_WATCHDOG
 
           To compile this driver as a module, choose M here.
 
+config INTEL_MID_WATCHDOG
+        tristate "Intel MID Watchdog Timer"
+        depends on X86_INTEL_MID
+        select WATCHDOG_CORE
+        ---help---
+          Watchdog timer driver built into the Intel SCU for Intel MID
+          Platforms.
+
+          This driver currently supports only the watchdog evolution
+          implementation in SCU, available for Merrifield generation.
+
+          To compile this driver as a module, choose M here.
+
 config ITCO_WDT
         tristate "Intel TCO Timer/Watchdog"
         depends on (X86 || IA64) && PCI
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 1384531eaa45..7b8a91ed20e7 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -112,6 +112,7 @@ obj-$(CONFIG_W83977F_WDT) += w83977f_wdt.o
 obj-$(CONFIG_MACHZ_WDT) += machzwd.o
 obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
+obj-$(CONFIG_INTEL_MID_WATCHDOG) += intel-mid_wdt.o
 
 # M32R Architecture
 
diff --git a/drivers/watchdog/intel-mid_wdt.c b/drivers/watchdog/intel-mid_wdt.c
new file mode 100644
index 000000000000..ca66e8e74635
--- /dev/null
+++ b/drivers/watchdog/intel-mid_wdt.c
@@ -0,0 +1,184 @@
+/*
+ *      intel-mid_wdt: generic Intel MID SCU watchdog driver
+ *
+ *      Platforms supported so far:
+ *      - Merrifield only
+ *
+ *      Copyright (C) 2014 Intel Corporation. All rights reserved.
+ *      Contact: David Cohen <david.a.cohen@linux.intel.com>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of version 2 of the GNU General
+ *      Public License as published by the Free Software Foundation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/nmi.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/platform_data/intel-mid_wdt.h>
+
+#include <asm/intel_scu_ipc.h>
+#include <asm/intel-mid.h>
+
+#define IPC_WATCHDOG 0xf8
+
+#define MID_WDT_PRETIMEOUT              15
+#define MID_WDT_TIMEOUT_MIN             (1 + MID_WDT_PRETIMEOUT)
+#define MID_WDT_TIMEOUT_MAX             170
+#define MID_WDT_DEFAULT_TIMEOUT         90
+
+/* SCU watchdog messages */
+enum {
+        SCU_WATCHDOG_START = 0,
+        SCU_WATCHDOG_STOP,
+        SCU_WATCHDOG_KEEPALIVE,
+};
+
+static inline int wdt_command(int sub, u32 *in, int inlen)
+{
+        return intel_scu_ipc_command(IPC_WATCHDOG, sub, in, inlen, NULL, 0);
+}
+
+static int wdt_start(struct watchdog_device *wd)
+{
+        int ret, in_size;
+        int timeout = wd->timeout;
+        struct ipc_wd_start {
+                u32 pretimeout;
+                u32 timeout;
+        } ipc_wd_start = { timeout - MID_WDT_PRETIMEOUT, timeout };
+
+        /*
+         * SCU expects the input size for watchdog IPC to
+         * be based on 4 bytes
+         */
+        in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
+
+        ret = wdt_command(SCU_WATCHDOG_START, (u32 *)&ipc_wd_start, in_size);
+        if (ret) {
+                struct device *dev = watchdog_get_drvdata(wd);
+                dev_crit(dev, "error starting watchdog: %d\n", ret);
+        }
+
+        return ret;
+}
+
+static int wdt_ping(struct watchdog_device *wd)
+{
+        int ret;
+
+        ret = wdt_command(SCU_WATCHDOG_KEEPALIVE, NULL, 0);
+        if (ret) {
+                struct device *dev = watchdog_get_drvdata(wd);
+                dev_crit(dev, "Error executing keepalive: 0x%x\n", ret);
+        }
+
+        return ret;
+}
+
+static int wdt_stop(struct watchdog_device *wd)
+{
+        int ret;
+
+        ret = wdt_command(SCU_WATCHDOG_STOP, NULL, 0);
+        if (ret) {
+                struct device *dev = watchdog_get_drvdata(wd);
+                dev_crit(dev, "Error stopping watchdog: 0x%x\n", ret);
+        }
+
+        return ret;
+}
+
+static irqreturn_t mid_wdt_irq(int irq, void *dev_id)
+{
+        panic("Kernel Watchdog");
+
+        /* This code should not be reached */
+        return IRQ_HANDLED;
+}
+
+static const struct watchdog_info mid_wdt_info = {
+        .identity = "Intel MID SCU watchdog",
+        .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+};
+
+static const struct watchdog_ops mid_wdt_ops = {
+        .owner = THIS_MODULE,
+        .start = wdt_start,
+        .stop = wdt_stop,
+        .ping = wdt_ping,
+};
+
+static int mid_wdt_probe(struct platform_device *pdev)
+{
+        struct watchdog_device *wdt_dev;
+        struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
+        int ret;
+
+        if (!pdata) {
+                dev_err(&pdev->dev, "missing platform data\n");
+                return -EINVAL;
+        }
+
+        if (pdata->probe) {
+                ret = pdata->probe(pdev);
+                if (ret)
+                        return ret;
+        }
+
+        wdt_dev = devm_kzalloc(&pdev->dev, sizeof(*wdt_dev), GFP_KERNEL);
+        if (!wdt_dev)
+                return -ENOMEM;
+
+        wdt_dev->info = &mid_wdt_info;
+        wdt_dev->ops = &mid_wdt_ops;
+        wdt_dev->min_timeout = MID_WDT_TIMEOUT_MIN;
+        wdt_dev->max_timeout = MID_WDT_TIMEOUT_MAX;
+        wdt_dev->timeout = MID_WDT_DEFAULT_TIMEOUT;
+
+        watchdog_set_drvdata(wdt_dev, &pdev->dev);
+        platform_set_drvdata(pdev, wdt_dev);
+
+        ret = devm_request_irq(&pdev->dev, pdata->irq, mid_wdt_irq,
+                               IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
+                               wdt_dev);
+        if (ret) {
+                dev_err(&pdev->dev, "error requesting warning irq %d\n",
+                        pdata->irq);
+                return ret;
+        }
+
+        ret = watchdog_register_device(wdt_dev);
+        if (ret) {
+                dev_err(&pdev->dev, "error registering watchdog device\n");
+                return ret;
+        }
+
+        dev_info(&pdev->dev, "Intel MID watchdog device probed\n");
+
+        return 0;
+}
+
+static int mid_wdt_remove(struct platform_device *pdev)
+{
+        struct watchdog_device *wd = platform_get_drvdata(pdev);
+        watchdog_unregister_device(wd);
+        return 0;
+}
+
+static struct platform_driver mid_wdt_driver = {
+        .probe          = mid_wdt_probe,
+        .remove         = mid_wdt_remove,
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "intel_mid_wdt",
+        },
+};
+
+module_platform_driver(mid_wdt_driver);
+
+MODULE_AUTHOR("David Cohen <david.a.cohen@linux.intel.com>");
+MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/intel-mid_wdt.h b/include/linux/platform_data/intel-mid_wdt.h
new file mode 100644
index 000000000000..b98253466ace
--- /dev/null
+++ b/include/linux/platform_data/intel-mid_wdt.h
@@ -0,0 +1,22 @@
+/*
+ *      intel-mid_wdt: generic Intel MID SCU watchdog driver
+ *
+ *      Copyright (C) 2014 Intel Corporation. All rights reserved.
+ *      Contact: David Cohen <david.a.cohen@linux.intel.com>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of version 2 of the GNU General
+ *      Public License as published by the Free Software Foundation.
+ */
+
+#ifndef __INTEL_MID_WDT_H__
+#define __INTEL_MID_WDT_H__
+
+#include <linux/platform_device.h>
+
+struct intel_mid_wdt_pdata {
+        int irq;
+        int (*probe)(struct platform_device *pdev);
+};
+
+#endif /*__INTEL_MID_WDT_H__*/