[U-Boot] [PATCH v2 19/20] watchdog: Add support for Armada 37xx CPU watchdog
Marek Behún
marek.behun at nic.cz
Tue Apr 24 15:21:30 UTC 2018
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 <marek.behun at nic.cz>
---
arch/arm/dts/armada-37xx.dtsi | 6 ++
drivers/watchdog/Kconfig | 9 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/armada-37xx-wdt.c | 175 +++++++++++++++++++++++++++++++++++++
4 files changed, 191 insertions(+)
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 at 8300 {
+ compatible = "marvell,armada-3700-wdt";
+ reg = <0xd064 0x4>,
+ <0x8300 0x40>;
+ };
+
nb_periph_clk: nb-periph-clk at 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 4fee6dbd1f..e17aa2b835 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -18,6 +18,7 @@ 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 <marek.behun at nic.cz>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <wdt.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/soc.h>
+
+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,
+};
--
2.16.1
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