From: Marek Behún Date: Tue, 24 Apr 2018 15:21:30 +0000 (+0200) Subject: watchdog: Add support for Armada 37xx CPU watchdog X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=2b69a67389fc43d7e16ef8c31d2a8845572acff6;p=u-boot.git watchdog: Add support for Armada 37xx CPU watchdog This adds support for the CPU watchdog found on Marvell Armada 37xx SoCs. There are 4 counters which can be set as CPU watchdog counters. This driver uses the second counter (ID 1, counting from 0) (Marvell's Linux also uses second counter by default). In the future it could be adapted to use other counters, with definition in the device tree. Signed-off-by: Marek Behun Signed-off-by: Stefan Roese --- diff --git a/arch/arm/dts/armada-37xx.dtsi b/arch/arm/dts/armada-37xx.dtsi index 5b4a1a49bb..a1052add0c 100644 --- a/arch/arm/dts/armada-37xx.dtsi +++ b/arch/arm/dts/armada-37xx.dtsi @@ -107,6 +107,12 @@ status = "disabled"; }; + wdt: watchdog-timer@8300 { + compatible = "marvell,armada-3700-wdt"; + reg = <0xd064 0x4>, + <0x8300 0x40>; + }; + nb_periph_clk: nb-periph-clk@13000 { compatible = "marvell,armada-3700-periph-clock-nb"; reg = <0x13000 0x100>; diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index dca2c901ac..148c6a0d68 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -60,6 +60,15 @@ config WDT_SANDBOX can be probed and supports all of the methods of WDT, but does not really do anything. +config WDT_ARMADA_37XX + bool "Marvell Armada 37xx watchdog timer support" + depends on WDT && ARMADA_3700 + help + Enable this to support Watchdog Timer on Marvell Armada 37xx SoC. + There are 4 possible clocks which can be used on these SoCs. This + driver uses the second clock (ID 1), assuming that so will also + Linux's driver. + config WDT_ASPEED bool "Aspeed ast2400/ast2500 watchdog timer support" depends on WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index c6f8aa3b13..f405f51b93 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_TANGIER_WATCHDOG) += tangier_wdt.o obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o obj-$(CONFIG_WDT) += wdt-uclass.o obj-$(CONFIG_WDT_SANDBOX) += sandbox_wdt.o +obj-$(CONFIG_WDT_ARMADA_37XX) += armada-37xx-wdt.o obj-$(CONFIG_WDT_ASPEED) += ast_wdt.o obj-$(CONFIG_WDT_BCM6345) += bcm6345_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o diff --git a/drivers/watchdog/armada-37xx-wdt.c b/drivers/watchdog/armada-37xx-wdt.c new file mode 100644 index 0000000000..0fa4fda4fc --- /dev/null +++ b/drivers/watchdog/armada-37xx-wdt.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Marvell Armada 37xx SoC Watchdog Driver + * + * Marek Behun + */ + +#include +#include +#include +#include +#include +#include + +DECLARE_GLOBAL_DATA_PTR; + +struct a37xx_wdt { + void __iomem *sel_reg; + void __iomem *reg; + ulong clk_rate; + u64 timeout; +}; + +/* + * We use Counter 1 for watchdog timer, because so does Marvell's Linux by + * default. + */ + +#define CNTR_CTRL 0x10 +#define CNTR_CTRL_ENABLE 0x0001 +#define CNTR_CTRL_ACTIVE 0x0002 +#define CNTR_CTRL_MODE_MASK 0x000c +#define CNTR_CTRL_MODE_ONESHOT 0x0000 +#define CNTR_CTRL_PRESCALE_MASK 0xff00 +#define CNTR_CTRL_PRESCALE_MIN 2 +#define CNTR_CTRL_PRESCALE_SHIFT 8 + +#define CNTR_COUNT_LOW 0x14 +#define CNTR_COUNT_HIGH 0x18 + +static void set_counter_value(struct a37xx_wdt *priv) +{ + writel(priv->timeout & 0xffffffff, priv->reg + CNTR_COUNT_LOW); + writel(priv->timeout >> 32, priv->reg + CNTR_COUNT_HIGH); +} + +static void a37xx_wdt_enable(struct a37xx_wdt *priv) +{ + u32 reg = readl(priv->reg + CNTR_CTRL); + + reg |= CNTR_CTRL_ENABLE; + writel(reg, priv->reg + CNTR_CTRL); +} + +static void a37xx_wdt_disable(struct a37xx_wdt *priv) +{ + u32 reg = readl(priv->reg + CNTR_CTRL); + + reg &= ~CNTR_CTRL_ENABLE; + writel(reg, priv->reg + CNTR_CTRL); +} + +static int a37xx_wdt_reset(struct udevice *dev) +{ + struct a37xx_wdt *priv = dev_get_priv(dev); + + if (!priv->timeout) + return -EINVAL; + + a37xx_wdt_disable(priv); + set_counter_value(priv); + a37xx_wdt_enable(priv); + + return 0; +} + +static int a37xx_wdt_expire_now(struct udevice *dev, ulong flags) +{ + struct a37xx_wdt *priv = dev_get_priv(dev); + + a37xx_wdt_disable(priv); + priv->timeout = 0; + set_counter_value(priv); + a37xx_wdt_enable(priv); + + return 0; +} + +static int a37xx_wdt_start(struct udevice *dev, u64 ms, ulong flags) +{ + struct a37xx_wdt *priv = dev_get_priv(dev); + u32 reg; + + reg = readl(priv->reg + CNTR_CTRL); + + if (reg & CNTR_CTRL_ACTIVE) + return -EBUSY; + + /* set mode */ + reg = (reg & ~CNTR_CTRL_MODE_MASK) | CNTR_CTRL_MODE_ONESHOT; + + /* set prescaler to the min value */ + reg &= ~CNTR_CTRL_PRESCALE_MASK; + reg |= CNTR_CTRL_PRESCALE_MIN << CNTR_CTRL_PRESCALE_SHIFT; + + priv->timeout = ms * priv->clk_rate / 1000 / CNTR_CTRL_PRESCALE_MIN; + + writel(reg, priv->reg + CNTR_CTRL); + + set_counter_value(priv); + a37xx_wdt_enable(priv); + + return 0; +} + +static int a37xx_wdt_stop(struct udevice *dev) +{ + struct a37xx_wdt *priv = dev_get_priv(dev); + + a37xx_wdt_disable(priv); + + return 0; +} + +static int a37xx_wdt_probe(struct udevice *dev) +{ + struct a37xx_wdt *priv = dev_get_priv(dev); + fdt_addr_t addr; + + addr = dev_read_addr_index(dev, 0); + if (addr == FDT_ADDR_T_NONE) + goto err; + priv->sel_reg = (void __iomem *)addr; + + addr = dev_read_addr_index(dev, 1); + if (addr == FDT_ADDR_T_NONE) + goto err; + priv->reg = (void __iomem *)addr; + + priv->clk_rate = (ulong)get_ref_clk() * 1000000; + + a37xx_wdt_disable(priv); + + /* + * We use timer 1 as watchdog timer (because Marvell's Linux uses that + * timer as default), therefore we only set bit TIMER1_IS_WCHDOG_TIMER. + */ + writel(1 << 1, priv->sel_reg); + + return 0; +err: + dev_err(dev, "no io address\n"); + return -ENODEV; +} + +static const struct wdt_ops a37xx_wdt_ops = { + .start = a37xx_wdt_start, + .reset = a37xx_wdt_reset, + .stop = a37xx_wdt_stop, + .expire_now = a37xx_wdt_expire_now, +}; + +static const struct udevice_id a37xx_wdt_ids[] = { + { .compatible = "marvell,armada-3700-wdt" }, + {} +}; + +U_BOOT_DRIVER(a37xx_wdt) = { + .name = "armada_37xx_wdt", + .id = UCLASS_WDT, + .of_match = a37xx_wdt_ids, + .probe = a37xx_wdt_probe, + .priv_auto_alloc_size = sizeof(struct a37xx_wdt), + .ops = &a37xx_wdt_ops, +};