[PATCH v5 2/2] watchdog: mtk_wdt: mt8183: Add reset controller

Jiaxin Yu
2019-11-25T03:04:15Z

From: "yong.liang" <yong.liang@mediatek.com>

Add reset controller API in watchdog driver.
Besides watchdog, MTK toprgu module also provide sub-system (eg, audio,
camera, codec and connectivity) software reset functionality.

Signed-off-by: yong.liang <yong.liang@mediatek.com>
Signed-off-by: jiaxin.yu <jiaxin.yu@mediatek.com>
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
---
drivers/watchdog/Kconfig | 1 +
drivers/watchdog/mtk_wdt.c | 111 ++++++++++++++++++++++++++++++++++++-
2 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 2e07caab9db2..629249fe5305 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -717,6 +717,7 @@ config MEDIATEK_WATCHDOG
tristate "Mediatek SoCs watchdog support"
depends on ARCH_MEDIATEK || COMPILE_TEST
select WATCHDOG_CORE
+ select RESET_CONTROLLER
help
Say Y here to include support for the watchdog timer
in Mediatek SoCs.
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 9c3d0033260d..d29484c7940a 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -9,6 +9,9 @@
* Based on sunxi_wdt.c
*/

+#include <dt-bindings/reset-controller/mt2712-resets.h>
+#include <dt-bindings/reset-controller/mt8183-resets.h>
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
@@ -16,10 +19,12 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
#include <linux/types.h>
#include <linux/watchdog.h>
-#include <linux/delay.h>

#define WDT_MAX_TIMEOUT 31
#define WDT_MIN_TIMEOUT 1
@@ -44,6 +49,9 @@
#define WDT_SWRST 0x14
#define WDT_SWRST_KEY 0x1209

+#define WDT_SWSYSRST 0x18U
+#define WDT_SWSYS_RST_KEY 0x88000000
+
#define DRV_NAME "mtk-wdt"
#define DRV_VERSION "1.0"

@@ -53,8 +61,99 @@ static unsigned int timeout;
struct mtk_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
+ spinlock_t lock; /* protects WDT_SWSYSRST reg */
+ struct reset_controller_dev rcdev;
+};
+
+struct mtk_wdt_data {
+ int sw_rst_num;
};

+static const struct mtk_wdt_data mt2712_data = {
+ .sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
+};
+
+static const struct mtk_wdt_data mt8183_data = {
+ .sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
+};
+
+static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ unsigned int tmp;
+ unsigned long flags;
+ struct mtk_wdt_dev *data =
+ container_of(rcdev, struct mtk_wdt_dev, rcdev);
+
+ spin_lock_irqsave(&data->lock, flags);
+
+ tmp = __raw_readl(data->wdt_base + WDT_SWSYSRST);
+ tmp |= BIT(id);
+ tmp |= WDT_SWSYS_RST_KEY;
+ writel(tmp, data->wdt_base + WDT_SWSYSRST);
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ unsigned int tmp;
+ unsigned long flags;
+ struct mtk_wdt_dev *data =
+ container_of(rcdev, struct mtk_wdt_dev, rcdev);
+
+ spin_lock_irqsave(&data->lock, flags);
+
+ tmp = __raw_readl(data->wdt_base + WDT_SWSYSRST);
+ tmp &= ~BIT(id);
+ tmp |= WDT_SWSYS_RST_KEY;
+ writel(tmp, data->wdt_base + WDT_SWSYSRST);
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return 0;
+}
+
+static int toprgu_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ int ret;
+
+ ret = toprgu_reset_assert(rcdev, id);
+ if (ret)
+ return ret;
+
+ return toprgu_reset_deassert(rcdev, id);
+}
+
+static const struct reset_control_ops toprgu_reset_ops = {
+ .assert = toprgu_reset_assert,
+ .deassert = toprgu_reset_deassert,
+ .reset = toprgu_reset,
+};
+
+static int toprgu_register_reset_controller(struct platform_device *pdev,
+ int rst_num)
+{
+ int ret;
+ struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+ spin_lock_init(&mtk_wdt->lock);
+
+ mtk_wdt->rcdev.owner = THIS_MODULE;
+ mtk_wdt->rcdev.nr_resets = rst_num;
+ mtk_wdt->rcdev.ops = &toprgu_reset_ops;
+ mtk_wdt->rcdev.of_node = pdev->dev.of_node;
+ ret = reset_controller_register(&mtk_wdt->rcdev);
+ if (ret != 0)
+ dev_err(&pdev->dev,
+ "couldn't register wdt reset controller: %d\n", ret);
+ return ret;
+}
+
static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
unsigned long action, void *data)
{
@@ -155,6 +254,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mtk_wdt_dev *mtk_wdt;
+ struct mtk_wdt_data *wdt_data;
int err;

mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
@@ -190,6 +290,13 @@ static int mtk_wdt_probe(struct platform_device *pdev)
dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
mtk_wdt->wdt_dev.timeout, nowayout);

+ wdt_data = (struct mtk_wdt_data *)of_device_get_match_data(dev);
+ if (wdt_data) {
+ err = toprgu_register_reset_controller(pdev,
+ wdt_data->sw_rst_num);
+ if (err)
+ return err;
+ }
return 0;
}

@@ -218,7 +325,9 @@ static int mtk_wdt_resume(struct device *dev)
#endif

static const struct of_device_id mtk_wdt_dt_ids[] = {
+ { .compatible = "mediatek,mt2712-wdt", .data = &mt2712_data },
{ .compatible = "mediatek,mt6589-wdt" },
+ { .compatible = "mediatek,mt8183-wdt", .data = &mt8183_data },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
--
2.18.0