watchdog: Add Realtek RTD1295

Add a watchdog driver for the Realtek RTD1295 SoC.

Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_watchdog.c code and
mach-rtk119x/driver/dc2vo/fpga/include/iso_reg.h register defines.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 5a606a4..6fdf3f9 100644 (file)
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -787,6 +787,16 @@ config UNIPHIER_WATCHDOG
          To compile this driver as a module, choose M here: the
          module will be called uniphier_wdt.
 
+config RTD119X_WATCHDOG
+       bool "Realtek RTD119x/RTD129x watchdog support"
+       depends on ARCH_REALTEK || COMPILE_TEST
+       depends on OF
+       select WATCHDOG_CORE
+       default ARCH_REALTEK
+       help
+         Say Y here to include support for the watchdog timer in
+         Realtek RTD1295 SoCs.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT

diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 715a210..cb5fe3d 100644 (file)
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
 obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
 obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o
 obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
+obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o

diff --git a/drivers/watchdog/rtd119x_wdt.c b/drivers/watchdog/rtd119x_wdt.c
new file mode 100644 (file)
index 0000000..d001c17
--- /dev/null
+++ b/drivers/watchdog/rtd119x_wdt.c
@@ -0,0 +1,168 @@
+/*
+ * Realtek RTD129x watchdog
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define RTD119X_TCWCR          0x0
+#define RTD119X_TCWTR          0x4
+#define RTD119X_TCWOV          0xc
+
+#define RTD119X_TCWCR_WDEN_DISABLED            0xa5
+#define RTD119X_TCWCR_WDEN_ENABLED             0xff
+#define RTD119X_TCWCR_WDEN_MASK                        0xff
+
+#define RTD119X_TCWTR_WDCLR                    BIT(0)
+
+struct rtd119x_watchdog_device {
+       struct watchdog_device wdt_dev;
+       void __iomem *base;
+       struct clk *clk;
+};
+
+static int rtd119x_wdt_start(struct watchdog_device *wdev)
+{
+       struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
+       u32 val;
+
+       val = readl_relaxed(data->base + RTD119X_TCWCR);
+       val &= ~RTD119X_TCWCR_WDEN_MASK;
+       val |= RTD119X_TCWCR_WDEN_ENABLED;
+       writel(val, data->base + RTD119X_TCWCR);
+
+       return 0;
+}
+
+static int rtd119x_wdt_stop(struct watchdog_device *wdev)
+{
+       struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
+       u32 val;
+
+       val = readl_relaxed(data->base + RTD119X_TCWCR);
+       val &= ~RTD119X_TCWCR_WDEN_MASK;
+       val |= RTD119X_TCWCR_WDEN_DISABLED;
+       writel(val, data->base + RTD119X_TCWCR);
+
+       return 0;
+}
+
+static int rtd119x_wdt_ping(struct watchdog_device *wdev)
+{
+       struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
+
+       writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR);
+
+       return rtd119x_wdt_start(wdev);
+}
+
+static int rtd119x_wdt_set_timeout(struct watchdog_device *wdev, unsigned int val)
+{
+       struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
+
+       writel(val * clk_get_rate(data->clk), data->base + RTD119X_TCWOV);
+
+       data->wdt_dev.timeout = val;
+
+       return 0;
+}
+
+static const struct watchdog_ops rtd119x_wdt_ops = {
+       .owner = THIS_MODULE,
+       .start          = rtd119x_wdt_start,
+       .stop           = rtd119x_wdt_stop,
+       .ping           = rtd119x_wdt_ping,
+       .set_timeout    = rtd119x_wdt_set_timeout,
+};
+
+static const struct watchdog_info rtd119x_wdt_info = {
+       .identity = "rtd119x-wdt",
+       .options = 0,
+};
+
+static const struct of_device_id rtd119x_wdt_dt_ids[] = {
+        { .compatible = "realtek,rtd1295-watchdog" },
+        { }
+};
+
+static int rtd119x_wdt_probe(struct platform_device *pdev)
+{
+       struct rtd119x_watchdog_device *data;
+       struct resource *res;
+       int ret;
+
+       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       data->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(data->base))
+               return PTR_ERR(data->base);
+
+       data->clk = of_clk_get(pdev->dev.of_node, 0);
+       if (IS_ERR(data->clk))
+               return PTR_ERR(data->clk);
+
+       ret = clk_prepare_enable(data->clk);
+       if (ret) {
+               clk_put(data->clk);
+               return ret;
+       }
+
+       data->wdt_dev.info = &rtd119x_wdt_info;
+       data->wdt_dev.ops = &rtd119x_wdt_ops;
+       data->wdt_dev.timeout = 120;
+       data->wdt_dev.max_timeout = 0xffffffff / clk_get_rate(data->clk);
+       data->wdt_dev.min_timeout = 1;
+       data->wdt_dev.parent = &pdev->dev;
+
+       watchdog_stop_on_reboot(&data->wdt_dev);
+       watchdog_set_drvdata(&data->wdt_dev, data);
+       platform_set_drvdata(pdev, data);
+
+       writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR);
+       rtd119x_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
+       rtd119x_wdt_stop(&data->wdt_dev);
+
+       ret = devm_watchdog_register_device(&pdev->dev, &data->wdt_dev);
+       if (ret) {
+               clk_disable_unprepare(data->clk);
+               clk_put(data->clk);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int rtd119x_wdt_remove(struct platform_device *pdev)
+{
+       struct rtd119x_watchdog_device *data = platform_get_drvdata(pdev);
+
+       watchdog_unregister_device(&data->wdt_dev);
+
+       clk_disable_unprepare(data->clk);
+       clk_put(data->clk);
+
+       return 0;
+}
+
+static struct platform_driver rtd119x_wdt_driver = {
+       .probe = rtd119x_wdt_probe,
+       .remove = rtd119x_wdt_remove,
+       .driver = {
+               .name = "rtd1295-watchdog",
+               .of_match_table = rtd119x_wdt_dt_ids,
+       },
+};
+builtin_platform_driver(rtd119x_wdt_driver);