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Sat, 13 Nov 2021 04:47:42 -0500 (EST) From: Sven Peter To: Rob Herring , devicetree@vger.kernel.org Cc: Sven Peter , Wim Van Sebroeck , Guenter Roeck , Hector Martin , Alyssa Rosenzweig , Mark Kettenis , linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/2] dt-bindings: watchdog: Add Apple Watchdog Date: Sat, 13 Nov 2021 10:47:31 +0100 Message-Id: <20211113094732.73889-1-sven@svenpeter.dev> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211113_014753_272057_F8531391 X-CRM114-Status: GOOD ( 11.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Apple SoCs come with a simple embedded watchdog. This watchdog is also required in order to reset the SoC. Signed-off-by: Sven Peter Reviewed-by: Mark Kettenis Reviewed-by: Rob Herring --- .../bindings/watchdog/apple,wdt.yaml | 52 +++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 53 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/apple,wdt.yaml diff --git a/Documentation/devicetree/bindings/watchdog/apple,wdt.yaml b/Documentation/devicetree/bindings/watchdog/apple,wdt.yaml new file mode 100644 index 000000000000..e58c56a6fdf6 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/apple,wdt.yaml @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/watchdog/apple,wdt.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Apple SoC Watchdog + +allOf: + - $ref: "watchdog.yaml#" + +maintainers: + - Sven Peter + +properties: + compatible: + items: + - enum: + - apple,t8103-wdt + - apple,t6000-wdt + - const: apple,wdt + + reg: + maxItems: 1 + + clocks: + maxItems: 1 + + interrupts: + maxItems: 1 + +required: + - compatible + - reg + - clocks + - interrupts + +unevaluatedProperties: false + +examples: + - | + #include + #include + + wdt: watchdog@50000000 { + compatible = "apple,t8103-wdt", "apple,wdt"; + reg = <0x50000000 0x4000>; + clocks = <&clk>; + interrupts = ; + }; + +... diff --git a/MAINTAINERS b/MAINTAINERS index 5b7a13f706fa..ba480837724d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1749,6 +1749,7 @@ F: Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml F: Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml F: Documentation/devicetree/bindings/pci/apple,pcie.yaml F: Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml +F: Documentation/devicetree/bindings/watchdog/apple,wdt.yaml F: arch/arm64/boot/dts/apple/ F: drivers/i2c/busses/i2c-pasemi-core.c F: drivers/i2c/busses/i2c-pasemi-platform.c From patchwork Sat Nov 13 09:47:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Peter X-Patchwork-Id: 12692486 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11CA7C433F5 for ; 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Sat, 13 Nov 2021 04:47:45 -0500 (EST) From: Sven Peter To: Wim Van Sebroeck , Guenter Roeck Cc: Sven Peter , Hector Martin , Alyssa Rosenzweig , Rob Herring , Mark Kettenis , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/2] watchdog: Add Apple SoC watchdog driver Date: Sat, 13 Nov 2021 10:47:32 +0100 Message-Id: <20211113094732.73889-2-sven@svenpeter.dev> X-Mailer: git-send-email 2.30.1 (Apple Git-130) In-Reply-To: <20211113094732.73889-1-sven@svenpeter.dev> References: <20211113094732.73889-1-sven@svenpeter.dev> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211113_014753_272265_B730DBE7 X-CRM114-Status: GOOD ( 27.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add support for the watchdog timer found in Apple SoCs. This driver is also required to reboot these machines. Signed-off-by: Sven Peter Tested-by: Janne Grunau --- MAINTAINERS | 1 + drivers/watchdog/Kconfig | 12 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/apple_wdt.c | 223 +++++++++++++++++++++++++++++++++++ 4 files changed, 237 insertions(+) create mode 100644 drivers/watchdog/apple_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index ba480837724d..30a1444297a1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1756,6 +1756,7 @@ F: drivers/i2c/busses/i2c-pasemi-platform.c F: drivers/irqchip/irq-apple-aic.c F: drivers/mailbox/apple-mailbox.c F: drivers/pinctrl/pinctrl-apple-gpio.c +F: drivers/watchdog/apple_wdt.c F: include/dt-bindings/interrupt-controller/apple-aic.h F: include/dt-bindings/pinctrl/apple.h F: include/linux/apple-mailbox.h diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9d222ba17ec6..170dec880c8f 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -976,6 +976,18 @@ config MSC313E_WATCHDOG To compile this driver as a module, choose M here: the module will be called msc313e_wdt. +config APPLE_WATCHDOG + tristate "Apple SoC watchdog" + depends on ARCH_APPLE || COMPILE_TEST + select WATCHDOG_CORE + help + Say Y here to include support for the Watchdog found in Apple + SoCs such as the M1. Next to the common watchdog features this + driver is also required in order to reboot these SoCs. + + To compile this driver as a module, choose M here: the + module will be called apple_wdt. + # X86 (i386 + ia64 + x86_64) Architecture config ACQUIRE_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2ee97064145b..270a518bd8f3 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -93,6 +93,7 @@ obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o +obj-$(CONFIG_APPLE_WATCHDOG) += apple_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c new file mode 100644 index 000000000000..ff6d98aadffc --- /dev/null +++ b/drivers/watchdog/apple_wdt.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple SoC Watchdog driver + * + * Copyright (C) The Asahi Linux Contributors + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Apple Watchdog MMIO registers + * + * This HW block has three separate watchdogs. WD0 resets the machine + * to recovery mode and is not very useful for us. WD1 and WD2 trigger a normal + * machine reset. WD0 additionally supports a configurable interrupt. + * + * APPLE_WDT_WDx_CUR_TIME is a simple counter incremented for each tick of the + * reference clock. It can also be overwritten to any value. + * Whenever APPLE_WDT_CTRL_RESET_EN is set in APPLE_WDT_WDx_CTRL and + * APPLE_WDTx_WD1_CUR_TIME >= APPLE_WDTx_WD1_BITE_TIME the entire machine is + * reset. + * Whenever APPLE_WDT_CTRL_IRQ_EN is set and APPLE_WDTx_WD1_CUR_TIME >= + * APPLE_WDTx_WD1_BARK_TIME an interrupt is triggered and + * APPLE_WDT_CTRL_IRQ_STATUS is set. The interrupt can be cleared by writing + * 1 to APPLE_WDT_CTRL_IRQ_STATUS. + */ +#define APPLE_WDT_WD0_CUR_TIME 0x00 +#define APPLE_WDT_WD0_BITE_TIME 0x04 +#define APPLE_WDT_WD0_BARK_TIME 0x08 +#define APPLE_WDT_WD0_CTRL 0x0c + +#define APPLE_WDT_WD1_CUR_TIME 0x10 +#define APPLE_WDT_WD1_BITE_TIME 0x14 +#define APPLE_WDT_WD1_CTRL 0x1c + +#define APPLE_WDT_WD2_CUR_TIME 0x20 +#define APPLE_WDT_WD2_BITE_TIME 0x24 +#define APPLE_WDT_WD2_CTRL 0x2c + +#define APPLE_WDT_CTRL_IRQ_EN BIT(0) +#define APPLE_WDT_CTRL_IRQ_STATUS BIT(1) +#define APPLE_WDT_CTRL_RESET_EN BIT(2) + +struct apple_wdt { + struct watchdog_device wdd; + void __iomem *regs; + struct clk *clk; + u32 clk_rate; +}; + +static struct apple_wdt *to_apple_wdt(struct watchdog_device *wdd) +{ + return container_of(wdd, struct apple_wdt, wdd); +} + +static int apple_wdt_start(struct watchdog_device *wdd) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME); + writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL); + + return 0; +} + +static int apple_wdt_stop(struct watchdog_device *wdd) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CTRL); + + return 0; +} + +static int apple_wdt_ping(struct watchdog_device *wdd) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME); + + return 0; +} + +static int apple_wdt_set_timeout(struct watchdog_device *wdd, unsigned int s) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + u64 timeout; + + timeout = mul_u32_u32(wdt->clk_rate, s); + if (timeout > U32_MAX) + return -EINVAL; + + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME); + writel_relaxed(timeout, wdt->regs + APPLE_WDT_WD1_BITE_TIME); + + wdd->timeout = s; + + return 0; +} + +static unsigned int apple_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + u32 cur_time, reset_time; + + cur_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME); + reset_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_BITE_TIME); + + return (reset_time - cur_time) / wdt->clk_rate; +} + +static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode, + void *cmd) +{ + struct apple_wdt *wdt = to_apple_wdt(wdd); + + writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL); + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_BITE_TIME); + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME); + + /* flush writes and wait for the reset to be triggered */ + (void)readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME); + mdelay(150); + + return 0; +} + +static struct watchdog_ops apple_wdt_ops = { + .owner = THIS_MODULE, + .start = apple_wdt_start, + .stop = apple_wdt_stop, + .ping = apple_wdt_ping, + .set_timeout = apple_wdt_set_timeout, + .get_timeleft = apple_wdt_get_timeleft, + .restart = apple_wdt_restart, +}; + +static struct watchdog_info apple_wdt_info = { + .identity = "Apple SoC Watchdog", + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, +}; + +static int apple_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct apple_wdt *wdt; + int ret; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + platform_set_drvdata(pdev, wdt); + + wdt->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(wdt->regs)) + return PTR_ERR(wdt->regs); + + /* reset watchdog to safe defaults */ + writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CTRL); + writel_relaxed(U32_MAX, wdt->regs + APPLE_WDT_WD1_BITE_TIME); + + wdt->clk = devm_clk_get(dev, NULL); + if (IS_ERR(wdt->clk)) + return PTR_ERR(wdt->clk); + + ret = clk_prepare_enable(wdt->clk); + if (ret) + return ret; + + wdt->clk_rate = clk_get_rate(wdt->clk); + wdt->wdd.ops = &apple_wdt_ops; + wdt->wdd.info = &apple_wdt_info; + wdt->wdd.max_timeout = U32_MAX / wdt->clk_rate; + wdt->wdd.timeout = wdt->wdd.max_timeout; + + watchdog_stop_on_unregister(&wdt->wdd); + watchdog_set_restart_priority(&wdt->wdd, 128); + + ret = devm_watchdog_register_device(dev, &wdt->wdd); + if (ret < 0) { + clk_disable_unprepare(wdt->clk); + return ret; + } + + return 0; +} + +static int apple_wdt_remove(struct platform_device *pdev) +{ + struct apple_wdt *wdt = platform_get_drvdata(pdev); + + clk_disable_unprepare(wdt->clk); + return 0; +} + +static const struct of_device_id apple_wdt_of_match[] = { + { .compatible = "apple,wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, apple_wdt_of_match); + +static struct platform_driver apple_wdt_driver = { + .driver = { + .name = "apple-watchdog", + .of_match_table = apple_wdt_of_match, + }, + .probe = apple_wdt_probe, + .remove = apple_wdt_remove, +}; +module_platform_driver(apple_wdt_driver); + +MODULE_DESCRIPTION("Apple SoC watchdog driver"); +MODULE_AUTHOR("Sven Peter "); +MODULE_LICENSE("Dual MIT/GPL");