From: Casey Connolly Date: Wed, 23 Apr 2025 02:19:39 +0000 (+0000) Subject: watchdog: qcom: introduce qcom-wdt driver X-Git-Tag: v2025.10-rc1~91^2~44^2~29 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=530764de9fc8539cd2354501e9c42804bc4c4dac;p=pandora-u-boot.git watchdog: qcom: introduce qcom-wdt driver Some Qualcomm device vendors decide to turn the watchdog on in the bootloader, resulting in the device being reset if it isn't petted every ~30 seconds. Introduce a driver to keep the watchdog happy and prevent this annoying behaviour. Signed-off-by: Paul Sajna Co-authored-by: Paul Sajna Tested-by: Paul Sajna Reviewed-by: Stefan Roese Acked-by: Sumit Garg Reviewed-by: Neil Armstrong Link: https://lore.kernel.org/r/20250422-b4-qcom-wdt-v3-1-730d4d5a858d@paulsajna.com Signed-off-by: Casey Connolly --- diff --git a/configs/qcom_defconfig b/configs/qcom_defconfig index 5eb027ba27b..e53691df4ca 100644 --- a/configs/qcom_defconfig +++ b/configs/qcom_defconfig @@ -143,3 +143,5 @@ CONFIG_VIDEO_FONT_16X32=y CONFIG_SYS_WHITE_ON_BLACK=y CONFIG_NO_FB_CLEAR=y CONFIG_VIDEO_SIMPLE=y +CONFIG_WDT_QCOM=y +CONFIG_WDT=y diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index a0f2948335f..38519add771 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -335,6 +335,13 @@ config WDT_K3_RTI_FW_FILE endif +config WDT_QCOM + bool "Qualcomm watchdog timer support" + depends on WDT && ARCH_SNAPDRAGON + help + Select this to enable Qualcomm watchdog timer, which can be found on + some Qualcomm chips. + config WDT_RENESAS bool "Renesas watchdog timer support" depends on WDT && R8A779F0 diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index c4467d6e126..d52d17e1c90 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -55,3 +55,4 @@ obj-$(CONFIG_WDT_SUNXI) += sunxi_wdt.o obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o obj-$(CONFIG_WDT_ADI) += adi_wdt.o +obj-$(CONFIG_WDT_QCOM) += qcom-wdt.o diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c new file mode 100644 index 00000000000..3601ba93774 --- /dev/null +++ b/drivers/watchdog/qcom-wdt.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2014, The Linux Foundation. All rights reserved. + * Copyright (c) Linaro Ltd. 2024 + * + * Authors: + * Casey Connolly + * Paul Sajna + * + * Derived from linux/drivers/watchdog/qcom-wdt.c + */ + +#include +#include +#include + +#include + +enum wdt_reg { + WDT_RST, + WDT_EN, + WDT_STS, + WDT_BARK_TIME, + WDT_BITE_TIME, +}; + +struct qcom_wdt_match_data { + const u32 *offset; +}; + +struct qcom_wdt { + void __iomem *base; + const u32 *layout; +}; + +static const u32 reg_offset_data_kpss[] = { + [WDT_RST] = 0x4, + [WDT_EN] = 0x8, + [WDT_STS] = 0xC, + [WDT_BARK_TIME] = 0x10, + [WDT_BITE_TIME] = 0x14, +}; + +static const struct qcom_wdt_match_data match_data_kpss = { + .offset = reg_offset_data_kpss, +}; + +static void __iomem *wdt_addr(struct qcom_wdt *wdt, enum wdt_reg reg) +{ + return wdt->base + wdt->layout[reg]; +} + +int qcom_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) +{ + struct qcom_wdt *wdt = dev_get_priv(dev); + + writel(0, wdt_addr(wdt, WDT_EN)); + writel(1, wdt_addr(wdt, WDT_RST)); + writel(1, wdt_addr(wdt, WDT_EN)); + if (readl(wdt_addr(wdt, WDT_EN)) != 1) { + dev_err(dev, "Failed to enable Qualcomm watchdog!\n"); + return -EIO; + } + return 0; +} + +int qcom_wdt_stop(struct udevice *dev) +{ + struct qcom_wdt *wdt = dev_get_priv(dev); + + writel(0, wdt_addr(wdt, WDT_EN)); + if (readl(wdt_addr(wdt, WDT_EN))) { + dev_err(dev, "Failed to disable Qualcomm watchdog!\n"); + return -EIO; + } + + return 0; +} + +int qcom_wdt_reset(struct udevice *dev) +{ + struct qcom_wdt *wdt = dev_get_priv(dev); + + writel(1, wdt_addr(wdt, WDT_RST)); + return 0; +} + +static int qcom_wdt_probe(struct udevice *dev) +{ + struct qcom_wdt *wdt = dev_get_priv(dev); + struct qcom_wdt_match_data *data = (void *)dev_get_driver_data(dev); + + wdt->base = dev_read_addr_ptr(dev); + wdt->layout = data->offset; + + return 0; +} + +static const struct wdt_ops qcom_wdt_ops = { + .start = qcom_wdt_start, + .stop = qcom_wdt_stop, + .reset = qcom_wdt_reset, +}; + +static const struct udevice_id qcom_wdt_ids[] = { + { .compatible = "qcom,kpss-wdt", .data = (ulong)&match_data_kpss }, + {} +}; + +U_BOOT_DRIVER(qcom_wdt) = { + .name = "qcom_wdt", + .id = UCLASS_WDT, + .of_match = qcom_wdt_ids, + .ops = &qcom_wdt_ops, + .probe = qcom_wdt_probe, + .priv_auto = sizeof(struct qcom_wdt), +};