From 93d34faeda4cb8bb059a6b6fbff4f9969c6f41a7 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Sun, 22 Aug 2021 13:53:27 -0500 Subject: [PATCH] watchdog: Add a driver for the sunxi watchdog This driver supports the sun4i/sun6i/sun20i watchdog timers. They have a maximum timeout of 16 seconds. Signed-off-by: Samuel Holland Signed-off-by: Andre Przywara --- drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/sunxi_wdt.c | 188 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+) create mode 100644 drivers/watchdog/sunxi_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 7d2d6ea..d306054 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -27,6 +27,7 @@ config WATCHDOG_TIMEOUT_MSECS default 128000 if ARCH_MX31 || ARCH_MX5 || ARCH_MX6 default 128000 if ARCH_MX7 || ARCH_VF610 default 30000 if ARCH_SOCFPGA + default 16000 if ARCH_SUNXI default 60000 help Watchdog timeout in msec @@ -270,6 +271,13 @@ config WDT_STM32MP Enable the STM32 watchdog (IWDG) driver. Enable support to configure STM32's on-SoC watchdog. +config WDT_SUNXI + bool "Allwinner sunxi watchdog timer support" + depends on WDT && ARCH_SUNXI + default y + help + Enable support for the watchdog timer in Allwinner sunxi SoCs. + config XILINX_TB_WATCHDOG bool "Xilinx Axi watchdog timer support" depends on WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f14415b..fa7ce58 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -36,5 +36,6 @@ obj-$(CONFIG_WDT_SBSA) += sbsa_gwdt.o obj-$(CONFIG_WDT_K3_RTI) += rti_wdt.o obj-$(CONFIG_WDT_SP805) += sp805_wdt.o obj-$(CONFIG_WDT_STM32MP) += stm32mp_wdt.o +obj-$(CONFIG_WDT_SUNXI) += sunxi_wdt.o obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c new file mode 100644 index 0000000..b40a1d2 --- /dev/null +++ b/drivers/watchdog/sunxi_wdt.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Derived from linux/drivers/watchdog/sunxi_wdt.c: + * Copyright (C) 2013 Carlo Caione + * Copyright (C) 2012 Henrik Nordstrom + */ + +#include +#include +#include +#include + +#define MSEC_PER_SEC 1000 + +#define WDT_MAX_TIMEOUT 16 +#define WDT_TIMEOUT_MASK 0xf + +#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1)) + +#define WDT_MODE_EN BIT(0) + +struct sunxi_wdt_reg { + u8 wdt_ctrl; + u8 wdt_cfg; + u8 wdt_mode; + u8 wdt_timeout_shift; + u8 wdt_reset_mask; + u8 wdt_reset_val; + u32 wdt_key_val; +}; + +struct sunxi_wdt_priv { + void __iomem *base; + const struct sunxi_wdt_reg *regs; +}; + +/* Map of timeout in seconds to register value */ +static const u8 wdt_timeout_map[1 + WDT_MAX_TIMEOUT] = { + [0] = 0x0, + [1] = 0x1, + [2] = 0x2, + [3] = 0x3, + [4] = 0x4, + [5] = 0x5, + [6] = 0x6, + [7] = 0x7, + [8] = 0x7, + [9] = 0x8, + [10] = 0x8, + [11] = 0x9, + [12] = 0x9, + [13] = 0xa, + [14] = 0xa, + [15] = 0xb, + [16] = 0xb, +}; + +static int sunxi_wdt_reset(struct udevice *dev) +{ + struct sunxi_wdt_priv *priv = dev_get_priv(dev); + const struct sunxi_wdt_reg *regs = priv->regs; + void __iomem *base = priv->base; + + writel(WDT_CTRL_RELOAD, base + regs->wdt_ctrl); + + return 0; +} + +static int sunxi_wdt_start(struct udevice *dev, u64 timeout, ulong flags) +{ + struct sunxi_wdt_priv *priv = dev_get_priv(dev); + const struct sunxi_wdt_reg *regs = priv->regs; + void __iomem *base = priv->base; + u32 val; + + timeout /= MSEC_PER_SEC; + if (timeout > WDT_MAX_TIMEOUT) + timeout = WDT_MAX_TIMEOUT; + + /* Set system reset function */ + val = readl(base + regs->wdt_cfg); + val &= ~regs->wdt_reset_mask; + val |= regs->wdt_reset_val; + val |= regs->wdt_key_val; + writel(val, base + regs->wdt_cfg); + + /* Set timeout and enable watchdog */ + val = readl(base + regs->wdt_mode); + val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift); + val |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift; + val |= WDT_MODE_EN; + val |= regs->wdt_key_val; + writel(val, base + regs->wdt_mode); + + return sunxi_wdt_reset(dev); +} + +static int sunxi_wdt_stop(struct udevice *dev) +{ + struct sunxi_wdt_priv *priv = dev_get_priv(dev); + const struct sunxi_wdt_reg *regs = priv->regs; + void __iomem *base = priv->base; + + writel(regs->wdt_key_val, base + regs->wdt_mode); + + return 0; +} + +static int sunxi_wdt_expire_now(struct udevice *dev, ulong flags) +{ + int ret; + + ret = sunxi_wdt_start(dev, 0, flags); + if (ret) + return ret; + + mdelay(500); + + return 0; +} + +static const struct wdt_ops sunxi_wdt_ops = { + .reset = sunxi_wdt_reset, + .start = sunxi_wdt_start, + .stop = sunxi_wdt_stop, + .expire_now = sunxi_wdt_expire_now, +}; + +static const struct sunxi_wdt_reg sun4i_wdt_reg = { + .wdt_ctrl = 0x00, + .wdt_cfg = 0x04, + .wdt_mode = 0x04, + .wdt_timeout_shift = 3, + .wdt_reset_mask = 0x2, + .wdt_reset_val = 0x2, +}; + +static const struct sunxi_wdt_reg sun6i_wdt_reg = { + .wdt_ctrl = 0x10, + .wdt_cfg = 0x14, + .wdt_mode = 0x18, + .wdt_timeout_shift = 4, + .wdt_reset_mask = 0x3, + .wdt_reset_val = 0x1, +}; + +static const struct sunxi_wdt_reg sun20i_wdt_reg = { + .wdt_ctrl = 0x10, + .wdt_cfg = 0x14, + .wdt_mode = 0x18, + .wdt_timeout_shift = 4, + .wdt_reset_mask = 0x03, + .wdt_reset_val = 0x01, + .wdt_key_val = 0x16aa0000, +}; + +static const struct udevice_id sunxi_wdt_ids[] = { + { .compatible = "allwinner,sun4i-a10-wdt", .data = (ulong)&sun4i_wdt_reg }, + { .compatible = "allwinner,sun6i-a31-wdt", .data = (ulong)&sun6i_wdt_reg }, + { .compatible = "allwinner,sun20i-d1-wdt", .data = (ulong)&sun20i_wdt_reg }, + { /* sentinel */ } +}; + +static int sunxi_wdt_probe(struct udevice *dev) +{ + struct sunxi_wdt_priv *priv = dev_get_priv(dev); + + priv->base = dev_remap_addr(dev); + if (!priv->base) + return -EINVAL; + + priv->regs = (void *)dev_get_driver_data(dev); + if (!priv->regs) + return -EINVAL; + + sunxi_wdt_stop(dev); + + return 0; +} + +U_BOOT_DRIVER(sunxi_wdt) = { + .name = "sunxi_wdt", + .id = UCLASS_WDT, + .of_match = sunxi_wdt_ids, + .probe = sunxi_wdt_probe, + .priv_auto = sizeof(struct sunxi_wdt_priv), + .ops = &sunxi_wdt_ops, +}; -- 2.7.4