This patch adds a common driver for the Mediatek SoC integrated watchdog.
Signed-off-by: Ryder Lee ryder.lee@mediatek.com Tested-by: Matthias Brugger matthias.bgg@gmail.com Reviewed-by: Simon Glass sjg@chromium.org --- Changes since v4: None --- 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 02f4e1e..b919ef6 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.lee@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, +};