Add a driver for the watchdog timer block found in the Krait Processor
Subsystem (KPSS) on the MSM8960, APQ8064, and IPQ8064.

Signed-off-by: Josh Cartwright <jo...@codeaurora.org>
---
 drivers/watchdog/Kconfig    |  10 +++
 drivers/watchdog/Makefile   |   1 +
 drivers/watchdog/qcom-wdt.c | 145 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 drivers/watchdog/qcom-wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1d1330a..5ccb963 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -443,6 +443,16 @@ config TEGRA_WATCHDOG
          To compile this driver as a module, choose M here: the
          module will be called tegra_wdt.
 
+config QCOM_WDT
+       bool "QCOM watchdog"
+       depends on HAS_IOMEM
+       depends on ARCH_QCOM
+       select WATCHDOG_CORE
+       help
+         Say Y here to include Watchdog timer support for the watchdog found
+         on QCOM chipsets.  Currently supported targets are the MSM8960,
+         APQ8064, and IPQ8064.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 468c320..d645448 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
 obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
 obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
+obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
 obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
 obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
 
diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
new file mode 100644
index 0000000..e9409f5
--- /dev/null
+++ b/drivers/watchdog/qcom-wdt.c
@@ -0,0 +1,145 @@
+/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define WDT_RST                0x0
+#define WDT_EN         0x8
+#define WDT_BITE_TIME  0x24
+
+struct qcom_wdt {
+       struct watchdog_device  wdd;
+       unsigned long           freq;
+       void __iomem            *base;
+};
+
+static inline
+struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd)
+{
+       return container_of(wdd, struct qcom_wdt, wdd);
+}
+
+static int qcom_wdt_start(struct watchdog_device *wdd)
+{
+       struct qcom_wdt *wdt = to_qcom_wdt(wdd);
+
+       writel(0, wdt->base + WDT_EN);
+       writel(1, wdt->base + WDT_RST);
+       writel(wdd->timeout * wdt->freq, wdt->base + WDT_BITE_TIME);
+       writel(1, wdt->base + WDT_EN);
+       return 0;
+}
+
+static int qcom_wdt_stop(struct watchdog_device *wdd)
+{
+       struct qcom_wdt *wdt = to_qcom_wdt(wdd);
+
+       writel(0, wdt->base + WDT_EN);
+       return 0;
+}
+
+static int qcom_wdt_ping(struct watchdog_device *wdd)
+{
+       struct qcom_wdt *wdt = to_qcom_wdt(wdd);
+
+       writel(1, wdt->base + WDT_RST);
+       return 0;
+}
+
+static int qcom_wdt_set_timeout(struct watchdog_device *wdd,
+                               unsigned int timeout)
+{
+       wdd->timeout = timeout;
+       return qcom_wdt_start(wdd);
+}
+
+static const struct watchdog_ops qcom_wdt_ops = {
+       .start          = qcom_wdt_start,
+       .stop           = qcom_wdt_stop,
+       .ping           = qcom_wdt_ping,
+       .set_timeout    = qcom_wdt_set_timeout,
+       .owner          = THIS_MODULE,
+};
+
+static const struct watchdog_info qcom_wdt_info = {
+       .options        = WDIOF_KEEPALIVEPING
+                       | WDIOF_MAGICCLOSE
+                       | WDIOF_SETTIMEOUT,
+       .identity       = KBUILD_MODNAME,
+};
+
+static int qcom_watchdog_probe(struct platform_device *pdev)
+{
+       struct qcom_wdt *wdt;
+       struct resource *res;
+       u32 tmp;
+       int ret;
+
+       wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+       if (!wdt)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, wdt);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       wdt->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(wdt->base))
+               return PTR_ERR(wdt->base);
+
+       ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &tmp);
+       if (ret) {
+               dev_err(&pdev->dev, "unable to get clock-frequency\n");
+               return ret;
+       }
+
+       wdt->freq = tmp;
+
+       wdt->wdd.dev = &pdev->dev;
+       wdt->wdd.info = &qcom_wdt_info;
+       wdt->wdd.ops = &qcom_wdt_ops;
+       wdt->wdd.min_timeout = 1;
+       wdt->wdd.max_timeout = 0x10000000U / wdt->freq;
+       watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
+
+       ret = watchdog_register_device(&wdt->wdd);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to register watchdog\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static const struct of_device_id qcom_wdt_of_table[] = {
+       { .compatible = "qcom,kpss-wdt-msm8960", },
+       { .compatible = "qcom,kpss-wdt-apq8064", },
+       { .compatible = "qcom,kpss-wdt-ipq8064", },
+       { },
+};
+MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
+
+static struct platform_driver qcom_watchdog_driver = {
+       .probe  = qcom_watchdog_probe,
+       .driver = {
+               .name           = KBUILD_MODNAME,
+               .of_match_table = qcom_wdt_of_table,
+       },
+};
+module_platform_driver(qcom_watchdog_driver);
+
+MODULE_DESCRIPTION("QCOM KPSS Watchdog Driver");
+MODULE_LICENSE("GPL v2");
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

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