[PATCH 1/3] watchdog: qcom: add support for KPSS WDT

Josh Cartwright
2014-09-18T22:33:19Z

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 <joshc@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");