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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/watchdog/intel-mid_wdt.c
Initial import
Diffstat (limited to 'drivers/watchdog/intel-mid_wdt.c')
-rw-r--r--drivers/watchdog/intel-mid_wdt.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/watchdog/intel-mid_wdt.c b/drivers/watchdog/intel-mid_wdt.c
new file mode 100644
index 000000000..84f6701c3
--- /dev/null
+++ b/drivers/watchdog/intel-mid_wdt.c
@@ -0,0 +1,183 @@
+/*
+ * 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 = {
+ .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");