[PATCH 1/2] watchdog: add Intel MID watchdog driver support
From: David Cohen
Date: Tue Apr 08 2014 - 19:45:57 EST
Add initial Intel MID watchdog driver support.
This driver is an initial implementation of generic Intel MID watchdog
driver. Currently it supports Intel Merrifield platform.
Signed-off-by: Eric Ernst <eric.ernst@xxxxxxxxx>
Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
---
drivers/watchdog/Kconfig | 12 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/intel-mid_wdt.c | 209 +++++++++++++++++++++++++++++++++++++++
3 files changed, 222 insertions(+)
create mode 100644 drivers/watchdog/intel-mid_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 79d25894343a..4da09b8b2f11 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -643,6 +643,18 @@ config INTEL_SCU_WATCHDOG
To compile this driver as a module, choose M here.
+config INTEL_MID_WATCHDOG
+ bool "Intel MID SCU Watchdog Mobile Platforms"
+ depends on X86_INTEL_MID && 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 985a66cda76f..b927e7496eb4 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -113,6 +113,7 @@ 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..6339c6351454
--- /dev/null
+++ b/drivers/watchdog/intel-mid_wdt.c
@@ -0,0 +1,209 @@
+/*
+ * 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@xxxxxxxxxxxxxxx>
+ *
+ * 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 <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 double-word
+ */
+ in_size = (sizeof(ipc_wd_start) + 3) / 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 -EIO;
+ }
+
+ return 0;
+}
+
+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 -EIO;
+ }
+
+ return 0;
+}
+
+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 -EIO;
+ }
+
+ return 0;
+}
+
+static irqreturn_t mid_wdt_warning_irq(int irq, void *dev_id)
+{
+ /* Let's dump some data before panic */
+ trigger_all_cpu_backtrace();
+ panic("Kernel Watchdog");
+
+ /* This code should not be reached */
+ return IRQ_HANDLED;
+}
+
+/*
+ * Current driver supports Merrifield only.
+ * This function will get more generic when necessary.
+ */
+static int handle_dev_ioapic(struct device *dev, int irq)
+{
+ int ioapic;
+ struct io_apic_irq_attr irq_attr;
+
+ ioapic = mp_find_ioapic(irq);
+ if (ioapic >= 0) {
+ irq_attr.ioapic = ioapic;
+ irq_attr.ioapic_pin = irq;
+ irq_attr.trigger = 1;
+ irq_attr.polarity = 0; /* Active high */
+ io_apic_set_pci_routing(NULL, irq, &irq_attr);
+ } else {
+ dev_warn(dev, "can not find interrupt %d in ioapic\n", irq);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+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 resource *res;
+ int ret;
+ int irq;
+
+ 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);
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "missing IRQ resource\n");
+ return -EINVAL;
+ }
+ irq = res->start;
+
+ handle_dev_ioapic(&pdev->dev, irq);
+ ret = devm_request_irq(&pdev->dev, irq, mid_wdt_warning_irq,
+ IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
+ wdt_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "error requesting warning irq %d\n", 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@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform");
+MODULE_LICENSE("GPL");
--
1.9.0
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