[PATCH 2/2] watchdog: mediatek: mt7988: add wdt support

[Daniel Golle <daniel@makrotopia.org>]

Add support for watchdog and reset generator unit of the MediaTek
MT7988 SoC.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/watchdog/mtk_wdt.c | 56 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index b2330b16b497a..b98b8c29735aa 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -12,6 +12,7 @@
 #include <dt-bindings/reset/mt2712-resets.h>
 #include <dt-bindings/reset/mediatek,mt6795-resets.h>
 #include <dt-bindings/reset/mt7986-resets.h>
+#include <dt-bindings/reset/mediatek,mt7988-resets.h>
 #include <dt-bindings/reset/mt8183-resets.h>
 #include <dt-bindings/reset/mt8186-resets.h>
 #include <dt-bindings/reset/mt8188-resets.h>
@@ -58,6 +59,8 @@
 #define WDT_SWSYSRST		0x18U
 #define WDT_SWSYS_RST_KEY	0x88000000
 
+#define WDT_SWSYSRST_EN		0xfc
+
 #define DRV_NAME		"mtk-wdt"
 #define DRV_VERSION		"1.0"
 
@@ -71,44 +74,85 @@ struct mtk_wdt_dev {
 	struct reset_controller_dev rcdev;
 	bool disable_wdt_extrst;
 	bool reset_by_toprgu;
+	bool has_swsysrst_en;
 };
 
 struct mtk_wdt_data {
 	int toprgu_sw_rst_num;
+	bool has_swsysrst_en;
 };
 
 static const struct mtk_wdt_data mt2712_data = {
 	.toprgu_sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt6795_data = {
 	.toprgu_sw_rst_num = MT6795_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt7986_data = {
 	.toprgu_sw_rst_num = MT7986_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
+};
+
+static const struct mtk_wdt_data mt7988_data = {
+	.toprgu_sw_rst_num = MT7988_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = true,
 };
 
 static const struct mtk_wdt_data mt8183_data = {
 	.toprgu_sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt8186_data = {
 	.toprgu_sw_rst_num = MT8186_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt8188_data = {
 	.toprgu_sw_rst_num = MT8188_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt8192_data = {
 	.toprgu_sw_rst_num = MT8192_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
 static const struct mtk_wdt_data mt8195_data = {
 	.toprgu_sw_rst_num = MT8195_TOPRGU_SW_RST_NUM,
+	.has_swsysrst_en = false,
 };
 
+static int toprgu_reset_sw_enable(struct reset_controller_dev *rcdev,
+				  unsigned long id, bool enable)
+{
+	unsigned int tmp;
+	unsigned long flags;
+	struct mtk_wdt_dev *data =
+		 container_of(rcdev, struct mtk_wdt_dev, rcdev);
+
+	if (!data->has_swsysrst_en)
+		return 0;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	tmp = readl(data->wdt_base + WDT_SWSYSRST_EN);
+	if (enable)
+		tmp |= BIT(id);
+	else
+		tmp &= ~BIT(id);
+
+	writel(tmp, data->wdt_base + WDT_SWSYSRST_EN);
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
 static int toprgu_reset_update(struct reset_controller_dev *rcdev,
 			       unsigned long id, bool assert)
 {
@@ -135,13 +179,20 @@ static int toprgu_reset_update(struct reset_controller_dev *rcdev,
 static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
 			       unsigned long id)
 {
+	int ret;
+
+	ret = toprgu_reset_sw_enable(rcdev, id, true);
+	if (ret)
+		return ret;
+
 	return toprgu_reset_update(rcdev, id, true);
 }
 
 static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
 				 unsigned long id)
 {
-	return toprgu_reset_update(rcdev, id, false);
+	toprgu_reset_update(rcdev, id, false);
+	return toprgu_reset_sw_enable(rcdev, id, false);
 }
 
 static int toprgu_reset(struct reset_controller_dev *rcdev,
@@ -406,6 +457,8 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 						       wdt_data->toprgu_sw_rst_num);
 		if (err)
 			return err;
+
+		mtk_wdt->has_swsysrst_en = wdt_data->has_swsysrst_en;
 	}
 
 	mtk_wdt->disable_wdt_extrst =
@@ -444,6 +497,7 @@ static const struct of_device_id mtk_wdt_dt_ids[] = {
 	{ .compatible = "mediatek,mt6589-wdt" },
 	{ .compatible = "mediatek,mt6795-wdt", .data = &mt6795_data },
 	{ .compatible = "mediatek,mt7986-wdt", .data = &mt7986_data },
+	{ .compatible = "mediatek,mt7988-wdt", .data = &mt7988_data },
 	{ .compatible = "mediatek,mt8183-wdt", .data = &mt8183_data },
 	{ .compatible = "mediatek,mt8186-wdt", .data = &mt8186_data },
 	{ .compatible = "mediatek,mt8188-wdt", .data = &mt8188_data },
-- 
2.42.1