diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/apple_wdt.c | 115 |
3 files changed, 125 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 1177f17fd8a..cabac290539 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -81,6 +81,15 @@ config WDT What exactly happens when the timer expires is up to a particular device/driver. +config WDT_APPLE + bool "Apple watchdog timer support" + depends on WDT + default y if ARCH_APPLE + help + Enable support for the watchdog timer on Apple SoCs. + The watchdog will perform a full SoC reset resulting in a + reboot of the entire system. + config WDT_ARMADA_37XX bool "Marvell Armada 37xx watchdog timer support" depends on WDT && ARMADA_3700 diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index fa7ce583ce2..6d2b3822c06 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o obj-$(CONFIG_$(SPL_TPL_)WDT) += wdt-uclass.o obj-$(CONFIG_WDT_SANDBOX) += sandbox_wdt.o +obj-$(CONFIG_WDT_APPLE) += apple_wdt.o obj-$(CONFIG_WDT_ARMADA_37XX) += armada-37xx-wdt.o obj-$(CONFIG_WDT_ASPEED) += ast_wdt.o obj-$(CONFIG_WDT_AST2600) += ast2600_wdt.o diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c new file mode 100644 index 00000000000..c7307f41cb7 --- /dev/null +++ b/drivers/watchdog/apple_wdt.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org> + */ + +#include <clk.h> +#include <dm.h> +#include <wdt.h> +#include <asm/io.h> +#include <linux/delay.h> + +#define APPLE_WDT_CUR_TIME 0x10 +#define APPLE_WDT_BARK_TIME 0x14 +#define APPLE_WDT_CTRL 0x1c +#define APPLE_WDT_CTRL_RESET_EN BIT(2) + +struct apple_wdt_priv { + void *base; + ulong clk_rate; +}; + +static int apple_wdt_reset(struct udevice *dev) +{ + struct apple_wdt_priv *priv = dev_get_priv(dev); + + writel(0, priv->base + APPLE_WDT_CUR_TIME); + + return 0; +} + +static int apple_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) +{ + struct apple_wdt_priv *priv = dev_get_priv(dev); + u64 timeout; + + timeout = (timeout_ms * priv->clk_rate) / 1000; + if (timeout > U32_MAX) + return -EINVAL; + + writel(0, priv->base + APPLE_WDT_CUR_TIME); + writel(timeout, priv->base + APPLE_WDT_BARK_TIME); + writel(APPLE_WDT_CTRL_RESET_EN, priv->base + APPLE_WDT_CTRL); + + return 0; +} + +static int apple_wdt_stop(struct udevice *dev) +{ + struct apple_wdt_priv *priv = dev_get_priv(dev); + + writel(0, priv->base + APPLE_WDT_CTRL); + + return 0; +} + +static int apple_wdt_expire_now(struct udevice *dev, ulong flags) +{ + int ret; + + ret = apple_wdt_start(dev, 0, flags); + if (ret) + return ret; + + /* + * It can take up to 25ms until the SoC actually resets, so + * wait 50ms just to be sure. + */ + mdelay(50); + + return 0; +} + +static const struct wdt_ops apple_wdt_ops = { + .reset = apple_wdt_reset, + .start = apple_wdt_start, + .stop = apple_wdt_stop, + .expire_now = apple_wdt_expire_now, +}; + +static const struct udevice_id apple_wdt_ids[] = { + { .compatible = "apple,wdt" }, + { /* sentinel */ } +}; + +static int apple_wdt_probe(struct udevice *dev) +{ + struct apple_wdt_priv *priv = dev_get_priv(dev); + struct clk clk; + int ret; + + priv->base = dev_read_addr_ptr(dev); + if (!priv->base) + return -EINVAL; + + ret = clk_get_by_index(dev, 0, &clk); + if (ret) + return ret; + + ret = clk_enable(&clk); + if (ret) + return ret; + + priv->clk_rate = clk_get_rate(&clk); + + return 0; +} + +U_BOOT_DRIVER(apple_wdt) = { + .name = "apple_wdt", + .id = UCLASS_WDT, + .of_match = apple_wdt_ids, + .priv_auto = sizeof(struct apple_wdt_priv), + .probe = apple_wdt_probe, + .ops = &apple_wdt_ops, +}; |