This patch adds watchdog support for the Mediatek MT7620 SoC
Signed-off-by: Weijie Gao <weijie....@mediatek.com>
---
v2 changes: add expire_now
---
drivers/watchdog/Kconfig | 7 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/mt7620_wdt.c | 132 ++++++++++++++++++++++++++++++++++
3 files changed, 140 insertions(+)
create mode 100644 drivers/watchdog/mt7620_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 210d9f8093..35d078caa0 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -124,6 +124,13 @@ config WDT_MPC8xx
help
Select this to enable mpc8xx watchdog timer
+config WDT_MT7620
+ bool "MediaTek MT7620 watchdog timer support"
+ depends on WDT && SOC_MT7620
+ help
+ Select this to enable watchdog timer on MediaTek MT7620 and earlier
+ SoC chips.
+
config WDT_MT7621
bool "MediaTek MT7621 watchdog timer support"
depends on WDT && SOC_MT7628
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 01b8231f2b..825b50e626 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_WDT_CORTINA) += cortina_wdt.o
obj-$(CONFIG_WDT_ORION) += orion_wdt.o
obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o
+obj-$(CONFIG_WDT_MT7620) += mt7620_wdt.o
obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
obj-$(CONFIG_WDT_MTK) += mtk_wdt.o
obj-$(CONFIG_WDT_OCTEONTX) += octeontx_wdt.o
diff --git a/drivers/watchdog/mt7620_wdt.c b/drivers/watchdog/mt7620_wdt.c
new file mode 100644
index 0000000000..2643167f8f
--- /dev/null
+++ b/drivers/watchdog/mt7620_wdt.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc.
+ *
+ * Author: Weijie Gao <weijie....@mediatek.com>
+ *
+ * Watchdog timer for MT7620 and earlier SoCs
+ */
+
+#include <div64.h>
+#include <dm.h>
+#include <reset.h>
+#include <wdt.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+
+struct mt7620_wdt {
+ void __iomem *regs;
+ u64 timeout;
+};
+
+#define TIMER_FREQ 40000000
+#define TIMER_MASK 0xffff
+#define TIMER_PRESCALE 65536
+
+#define TIMER_LOAD 0x00
+#define TIMER_CTL 0x08
+
+#define TIMER_ENABLE BIT(7)
+#define TIMER_MODE_SHIFT 4
+#define TIMER_MODE_WDT 3
+#define TIMER_PRESCALE_SHIFT 0
+#define TIMER_PRESCALE_65536 15
+
+static void mt7620_wdt_ping(struct mt7620_wdt *priv)
+{
+ u64 val;
+
+ val = (TIMER_FREQ / TIMER_PRESCALE) * priv->timeout;
+ do_div(val, 1000);
+
+ if (val > TIMER_MASK)
+ val = TIMER_MASK;
+
+ writel(val, priv->regs + TIMER_LOAD);
+}
+
+static int mt7620_wdt_start(struct udevice *dev, u64 ms, ulong flags)
+{
+ struct mt7620_wdt *priv = dev_get_priv(dev);
+
+ priv->timeout = ms;
+ mt7620_wdt_ping(priv);
+
+ writel(TIMER_ENABLE | (TIMER_MODE_WDT << TIMER_MODE_SHIFT) |
+ (TIMER_PRESCALE_65536 << TIMER_PRESCALE_SHIFT),
+ priv->regs + TIMER_CTL);
+
+ return 0;
+}
+
+static int mt7620_wdt_stop(struct udevice *dev)
+{
+ struct mt7620_wdt *priv = dev_get_priv(dev);
+
+ mt7620_wdt_ping(priv);
+
+ clrbits_32(priv->regs + TIMER_CTL, TIMER_ENABLE);
+
+ return 0;
+}
+
+static int mt7620_wdt_reset(struct udevice *dev)
+{
+ struct mt7620_wdt *priv = dev_get_priv(dev);
+
+ mt7620_wdt_ping(priv);
+
+ return 0;
+}
+
+static int mt7620_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ struct mt7620_wdt *priv = dev_get_priv(dev);
+
+ mt7620_wdt_start(dev, 1, flags);
+
+ /* 0 will disable the timer, so use 1 instead */
+ writel(1, priv->regs + TIMER_LOAD);
+
+ return 0;
+}
+
+static int mt7620_wdt_probe(struct udevice *dev)
+{
+ struct mt7620_wdt *priv = dev_get_priv(dev);
+ struct reset_ctl reset_wdt;
+ int ret;
+
+ ret = reset_get_by_index(dev, 0, &reset_wdt);
+ if (!ret)
+ reset_deassert(&reset_wdt);
+
+ priv->regs = dev_remap_addr(dev);
+ if (!priv->regs)
+ return -EINVAL;
+
+ mt7620_wdt_stop(dev);
+
+ return 0;
+}
+
+static const struct wdt_ops mt7620_wdt_ops = {
+ .start = mt7620_wdt_start,
+ .reset = mt7620_wdt_reset,
+ .stop = mt7620_wdt_stop,
+ .expire_now = mt7620_wdt_expire_now,
+};
+
+static const struct udevice_id mt7620_wdt_ids[] = {
+ { .compatible = "mediatek,mt7620-wdt" },
+ {}
+};
+
+U_BOOT_DRIVER(mt7620_wdt) = {
+ .name = "mt7620_wdt",
+ .id = UCLASS_WDT,
+ .of_match = mt7620_wdt_ids,
+ .probe = mt7620_wdt_probe,
+ .priv_auto_alloc_size = sizeof(struct mt7620_wdt),
+ .ops = &mt7620_wdt_ops,
+};
--
2.17.1
