This patch adds a common driver for the Mediatek SoC integrated watchdog.
Signed-off-by: Ryder Lee <ryder....@mediatek.com>
---
drivers/watchdog/Kconfig | 8 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mtk_wdt.c | 135 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 144 insertions(+)
create mode 100644 drivers/watchdog/mtk_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index d545b3e..57a12f5 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -103,6 +103,14 @@ config WDT_CDNS
Select this to enable Cadence watchdog timer, which can be found on
some
Xilinx Microzed Platform.
+config WDT_MTK
+ bool "MediaTek watchdog timer support"
+ depends on WDT && ARCH_MEDIATEK
+ help
+ Select this to enable watchdog timer for MediaTek SoCs.
+ The watchdog timer is stopped when initialized.
+ It performs full SoC reset.
+
config XILINX_TB_WATCHDOG
bool "Xilinx Axi watchdog timer support"
depends on WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 08406ca..04fa4a6 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
obj-$(CONFIG_WDT_ORION) += orion_wdt.o
obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
obj-$(CONFIG_MPC8xx_WATCHDOG) += mpc8xx_wdt.o
+obj-$(CONFIG_WDT_MTK) += mtk_wdt.o
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
new file mode 100644
index 0000000..0b50173
--- /dev/null
+++ b/drivers/watchdog/mtk_wdt.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Watchdog driver for MediaTek SoCs
+ *
+ * Copyright (C) 2018 MediaTek Inc.
+ * Author: Ryder Lee <ryder....@mediatek.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <wdt.h>
+#include <asm/io.h>
+
+#define MTK_WDT_MODE 0x00
+#define MTK_WDT_LENGTH 0x04
+#define MTK_WDT_RESTART 0x08
+#define MTK_WDT_STATUS 0x0c
+#define MTK_WDT_INTERVAL 0x10
+#define MTK_WDT_SWRST 0x14
+#define MTK_WDT_REQ_MODE 0x30
+#define MTK_WDT_DEBUG_CTL 0x40
+
+#define WDT_MODE_KEY (0x22 << 24)
+#define WDT_MODE_EN BIT(0)
+#define WDT_MODE_EXTPOL BIT(1)
+#define WDT_MODE_EXTEN BIT(2)
+#define WDT_MODE_IRQ_EN BIT(3)
+#define WDT_MODE_DUAL_EN BIT(6)
+
+#define WDT_LENGTH_KEY 0x8
+#define WDT_LENGTH_TIMEOUT(n) ((n) << 5)
+
+#define WDT_RESTART_KEY 0x1971
+#define WDT_SWRST_KEY 0x1209
+
+struct mtk_wdt_priv {
+ void __iomem *base;
+};
+
+static int mtk_wdt_reset(struct udevice *dev)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ /* Reload watchdog duration */
+ writel(WDT_RESTART_KEY, priv->base + MTK_WDT_RESTART);
+
+ return 0;
+}
+
+static int mtk_wdt_stop(struct udevice *dev)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ clrsetbits_le32(priv->base + MTK_WDT_MODE, WDT_MODE_EN, WDT_MODE_KEY);
+
+ return 0;
+}
+
+static int mtk_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ /* Kick watchdog to prevent counter == 0 */
+ writel(WDT_RESTART_KEY, priv->base + MTK_WDT_RESTART);
+
+ /* Reset */
+ writel(WDT_SWRST_KEY, priv->base + MTK_WDT_SWRST);
+ hang();
+
+ return 0;
+}
+
+static void mtk_wdt_set_timeout(struct udevice *dev, unsigned int timeout)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ /*
+ * One bit is the value of 512 ticks
+ * The clock has 32 KHz
+ */
+ timeout = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
+ writel(timeout, priv->base + MTK_WDT_LENGTH);
+
+ mtk_wdt_reset(dev);
+}
+
+static int mtk_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ mtk_wdt_set_timeout(dev, timeout);
+
+ /* Enable watchdog reset signal */
+ setbits_le32(priv->base + MTK_WDT_MODE,
+ WDT_MODE_EN | WDT_MODE_KEY | WDT_MODE_EXTEN);
+
+ return 0;
+}
+
+static int mtk_wdt_probe(struct udevice *dev)
+{
+ struct mtk_wdt_priv *priv = dev_get_priv(dev);
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -ENOENT;
+
+ /* Clear status */
+ clrsetbits_le32(priv->base + MTK_WDT_MODE,
+ WDT_MODE_IRQ_EN | WDT_MODE_EXTPOL, WDT_MODE_KEY);
+
+ return mtk_wdt_stop(dev);
+}
+
+static const struct wdt_ops mtk_wdt_ops = {
+ .start = mtk_wdt_start,
+ .reset = mtk_wdt_reset,
+ .stop = mtk_wdt_stop,
+ .expire_now = mtk_wdt_expire_now,
+};
+
+static const struct udevice_id mtk_wdt_ids[] = {
+ { .compatible = "mediatek,wdt"},
+ {}
+};
+
+U_BOOT_DRIVER(mtk_wdt) = {
+ .name = "mtk_wdt",
+ .id = UCLASS_WDT,
+ .of_match = mtk_wdt_ids,
+ .priv_auto_alloc_size = sizeof(struct mtk_wdt_priv),
+ .probe = mtk_wdt_probe,
+ .ops = &mtk_wdt_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
1.9.1
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