diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | drivers/watchdog/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/gunyah_wdt.c | 261 |
4 files changed, 276 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 2fb1c75afd16..f35e1769fa72 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3337,6 +3337,7 @@ F: arch/arm64/boot/dts/qcom/ F: drivers/bus/qcom* F: drivers/firmware/qcom/ F: drivers/soc/qcom/ +F: drivers/watchdog/gunyah_wdt.c F: include/dt-bindings/arm/qcom,ids.h F: include/dt-bindings/firmware/qcom,scm.h F: include/dt-bindings/soc/qcom* diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 8de43b614bb7..3397c82ded9c 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -2341,4 +2341,17 @@ config KEEMBAY_WATCHDOG To compile this driver as a module, choose M here: the module will be called keembay_wdt. +config GUNYAH_WATCHDOG + tristate "Qualcomm Gunyah Watchdog" + depends on ARCH_QCOM || COMPILE_TEST + depends on HAVE_ARM_SMCCC + select WATCHDOG_CORE + help + Say Y here to include support for watchdog timer provided by the + Gunyah hypervisor. The driver uses ARM SMC Calling Convention (SMCCC) + to interact with Gunyah Watchdog. + + To compile this driver as a module, choose M here: the + module will be called gunyah_wdt. + endif # WATCHDOG diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2961ca141c61..ff1dc6fd5867 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -103,6 +103,7 @@ obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o obj-$(CONFIG_APPLE_WATCHDOG) += apple_wdt.o obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o obj-$(CONFIG_MARVELL_GTI_WDT) += marvell_gti_wdt.o +obj-$(CONFIG_GUNYAH_WATCHDOG) += gunyah_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/gunyah_wdt.c b/drivers/watchdog/gunyah_wdt.c new file mode 100644 index 000000000000..49dfef459e84 --- /dev/null +++ b/drivers/watchdog/gunyah_wdt.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#include <linux/arm-smccc.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +#define GUNYAH_WDT_SMCCC_CALL_VAL(func_id) \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32,\ + ARM_SMCCC_OWNER_VENDOR_HYP, func_id) + +/* SMCCC function IDs for watchdog operations */ +#define GUNYAH_WDT_CONTROL GUNYAH_WDT_SMCCC_CALL_VAL(0x0005) +#define GUNYAH_WDT_STATUS GUNYAH_WDT_SMCCC_CALL_VAL(0x0006) +#define GUNYAH_WDT_PING GUNYAH_WDT_SMCCC_CALL_VAL(0x0007) +#define GUNYAH_WDT_SET_TIME GUNYAH_WDT_SMCCC_CALL_VAL(0x0008) + +/* + * Control values for GUNYAH_WDT_CONTROL. + * Bit 0 is used to enable or disable the watchdog. If this bit is set, + * then the watchdog is enabled and vice versa. + * Bit 1 should always be set to 1 as this bit is reserved in Gunyah and + * it's expected to be 1. + */ +#define WDT_CTRL_ENABLE (BIT(1) | BIT(0)) +#define WDT_CTRL_DISABLE BIT(1) + +enum gunyah_error { + GUNYAH_ERROR_OK = 0, + GUNYAH_ERROR_UNIMPLEMENTED = -1, + GUNYAH_ERROR_ARG_INVAL = 1, +}; + +/** + * gunyah_error_remap() - Remap Gunyah hypervisor errors into a Linux error code + * @gunyah_error: Gunyah hypercall return value + */ +static inline int gunyah_error_remap(enum gunyah_error gunyah_error) +{ + switch (gunyah_error) { + case GUNYAH_ERROR_OK: + return 0; + case GUNYAH_ERROR_UNIMPLEMENTED: + return -EOPNOTSUPP; + default: + return -EINVAL; + } +} + +static int gunyah_wdt_call(unsigned long func_id, unsigned long arg1, + unsigned long arg2) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(func_id, arg1, arg2, &res); + return gunyah_error_remap(res.a0); +} + +static int gunyah_wdt_start(struct watchdog_device *wdd) +{ + unsigned int timeout_ms; + struct device *dev = wdd->parent; + int ret; + + ret = gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_DISABLE, 0); + if (ret && watchdog_active(wdd)) { + dev_err(dev, "%s: Failed to stop gunyah wdt %d\n", __func__, ret); + return ret; + } + + timeout_ms = wdd->timeout * 1000; + ret = gunyah_wdt_call(GUNYAH_WDT_SET_TIME, timeout_ms, timeout_ms); + if (ret) { + dev_err(dev, "%s: Failed to set timeout for gunyah wdt %d\n", + __func__, ret); + return ret; + } + + ret = gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_ENABLE, 0); + if (ret) + dev_err(dev, "%s: Failed to start gunyah wdt %d\n", __func__, ret); + + return ret; +} + +static int gunyah_wdt_stop(struct watchdog_device *wdd) +{ + return gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_DISABLE, 0); +} + +static int gunyah_wdt_ping(struct watchdog_device *wdd) +{ + return gunyah_wdt_call(GUNYAH_WDT_PING, 0, 0); +} + +static int gunyah_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout_sec) +{ + wdd->timeout = timeout_sec; + + if (watchdog_active(wdd)) + return gunyah_wdt_start(wdd); + + return 0; +} + +static int gunyah_wdt_get_time_since_last_ping(void) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_smc(GUNYAH_WDT_STATUS, 0, 0, &res); + if (res.a0) + return gunyah_error_remap(res.a0); + + return res.a2 / 1000; +} + +static unsigned int gunyah_wdt_get_timeleft(struct watchdog_device *wdd) +{ + int seconds_since_last_ping; + + seconds_since_last_ping = gunyah_wdt_get_time_since_last_ping(); + if (seconds_since_last_ping < 0 || + seconds_since_last_ping > wdd->timeout) + return 0; + + return wdd->timeout - seconds_since_last_ping; +} + +static int gunyah_wdt_restart(struct watchdog_device *wdd, + unsigned long action, void *data) +{ + /* Set timeout to 1ms and send a ping */ + gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_DISABLE, 0); + gunyah_wdt_call(GUNYAH_WDT_SET_TIME, 1, 1); + gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_ENABLE, 0); + gunyah_wdt_call(GUNYAH_WDT_PING, 0, 0); + + /* Wait to make sure reset occurs */ + mdelay(100); + + return 0; +} + +static const struct watchdog_info gunyah_wdt_info = { + .identity = "Gunyah Watchdog", + .options = WDIOF_SETTIMEOUT + | WDIOF_KEEPALIVEPING + | WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops gunyah_wdt_ops = { + .owner = THIS_MODULE, + .start = gunyah_wdt_start, + .stop = gunyah_wdt_stop, + .ping = gunyah_wdt_ping, + .set_timeout = gunyah_wdt_set_timeout, + .get_timeleft = gunyah_wdt_get_timeleft, + .restart = gunyah_wdt_restart +}; + +static int gunyah_wdt_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdd; + struct device *dev = &pdev->dev; + int ret; + + ret = gunyah_wdt_call(GUNYAH_WDT_STATUS, 0, 0); + if (ret == -EOPNOTSUPP) + return -ENODEV; + + if (ret) + return dev_err_probe(dev, ret, "status check failed\n"); + + wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); + if (!wdd) + return -ENOMEM; + + wdd->info = &gunyah_wdt_info; + wdd->ops = &gunyah_wdt_ops; + wdd->parent = dev; + + /* + * Although Gunyah expects 16-bit unsigned int values as timeout values + * in milliseconds, values above 0x8000 are reserved. This limits the + * max timeout value to 32 seconds. + */ + wdd->max_timeout = 32; /* seconds */ + wdd->min_timeout = 1; /* seconds */ + wdd->timeout = wdd->max_timeout; + + gunyah_wdt_stop(wdd); + platform_set_drvdata(pdev, wdd); + watchdog_set_restart_priority(wdd, 0); + + return devm_watchdog_register_device(dev, wdd); +} + +static void gunyah_wdt_remove(struct platform_device *pdev) +{ + struct watchdog_device *wdd = platform_get_drvdata(pdev); + + gunyah_wdt_stop(wdd); +} + +static int gunyah_wdt_suspend(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + if (watchdog_active(wdd)) + gunyah_wdt_stop(wdd); + + return 0; +} + +static int gunyah_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + if (watchdog_active(wdd)) + gunyah_wdt_start(wdd); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(gunyah_wdt_pm_ops, gunyah_wdt_suspend, gunyah_wdt_resume); + +/* + * Gunyah watchdog is a vendor-specific hypervisor interface provided by the + * Gunyah hypervisor. Using QCOM SCM driver to detect Gunyah watchdog SMCCC + * hypervisor service and register platform device when the service is available + * allows this driver to operate independently of the devicetree and avoids + * adding the non-hardware nodes to the devicetree. + */ +static const struct platform_device_id gunyah_wdt_id[] = { + { .name = "gunyah-wdt" }, + {} +}; +MODULE_DEVICE_TABLE(platform, gunyah_wdt_id); + +static struct platform_driver gunyah_wdt_driver = { + .driver = { + .name = "gunyah-wdt", + .pm = pm_sleep_ptr(&gunyah_wdt_pm_ops), + }, + .id_table = gunyah_wdt_id, + .probe = gunyah_wdt_probe, + .remove = gunyah_wdt_remove, +}; + +module_platform_driver(gunyah_wdt_driver); + +MODULE_DESCRIPTION("Gunyah Watchdog Driver"); +MODULE_LICENSE("GPL"); |