Re: [PATCH 2/3] watchdog: Add Realtek RTD1295
From: Guenter Roeck
Date: Fri Sep 01 2017 - 12:22:11 EST
On 08/28/2017 04:35 AM, Andreas FÃrber wrote:
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 FÃrber <afaerber@xxxxxxx>
---
drivers/watchdog/Kconfig | 10 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/rtd119x_wdt.c | 152 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 163 insertions(+)
create mode 100644 drivers/watchdog/rtd119x_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c722cbfdc7e6..8fa81518c3fa 100644
--- 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 56adf9fa67d0..63cb3ed8117d 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -87,6 +87,7 @@ 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
index 000000000000..1bd2e86509a7
--- /dev/null
+++ b/drivers/watchdog/rtd119x_wdt.c
@@ -0,0 +1,152 @@
+/*
+ * Realtek RTD129x watchdog
+ *
+ * Copyright (c) 2017 Andreas FÃrber
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#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 RTD_TCWCR 0x0
+#define RTD_TCWTR 0x4
+#define RTD_TCWOV 0xc
+
+#define RTD_TCWCR_WDEN_DISABLED 0xa5
+#define RTD_TCWCR_WDEN_ENABLED 0xff
+#define RTD_TCWCR_WDEN_MASK 0xff
+
+#define RTD_TCWTR_WDCLR BIT(0)
+
need to include bitops.h.
+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 + RTD_TCWCR);
+ val &= ~RTD_TCWCR_WDEN_MASK;
+ val |= RTD_TCWCR_WDEN_ENABLED;
+ writel(val, data->base + RTD_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 + RTD_TCWCR);
+ val &= ~RTD_TCWCR_WDEN_MASK;
+ val |= RTD_TCWCR_WDEN_DISABLED;
+ writel(val, data->base + RTD_TCWCR);
+
+ return 0;
+}
+
+static int rtd119x_wdt_ping(struct watchdog_device *wdev)
+{
+ struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev);
+
+ writel_relaxed(RTD_TCWTR_WDCLR, data->base + RTD_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 * 27000000, data->base + RTD_TCWOV);
+
This also needs to set wdev->timeout.
+ 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 rtd_wdt_dt_ids[] = {
+ { .compatible = "realtek,rtd1295-watchdog" },
+ { }
+};
+
+static int rtd_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);
+
Not needed since there is no remove function.
+ writel_relaxed(RTD_TCWTR_WDCLR, data->base + RTD_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 struct platform_driver rtd_wdt_driver = {
+ .probe = rtd_wdt_probe,
+ .driver = {
+ .name = "rtd1295-watchdog",
+ .of_match_table = rtd_wdt_dt_ids,
+ },
+};
+builtin_platform_driver(rtd_wdt_driver);