[U-Boot] [patch v3 1/3] watchdog: add sp805 watchdog support
Qiang Zhao
qiang.zhao at nxp.com
Tue May 7 03:16:09 UTC 2019
sp805 is watchdog on some NXP layerscape SoCs, Now add its driver in uboot.
To add
CONFIG_WDT_SP805=y
CONFIG_WDT=y
CONFIG_CMD_WDT=y
in defconfig to use it.
Signed-off-by: Zhao Qiang <qiang.zhao at nxp.com>
---
MAINTAINERS | 1 +
drivers/watchdog/Kconfig | 7 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/sp805_wdt.c | 127 +++++++++++++++++++++++++++++++++++
4 files changed, 136 insertions(+)
create mode 100644 drivers/watchdog/sp805_wdt.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 8f237128b2..e8e7a92802 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -410,6 +410,7 @@ FREESCALE QORIQ
M: York Sun <york.sun at nxp.com>
S: Maintained
T: git git://git.denx.de/u-boot-fsl-qoriq.git
+F: drivers/watchdog/sp805_wdt.c
I2C
M: Heiko Schocher <hs at denx.de>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b06c5447f6..29e04630d2 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -95,6 +95,13 @@ config WDT_ORION
Select this to enable Orion watchdog timer, which can be found on some
Marvell Armada chips.
+config WDT_SP805
+ bool "SP805 watchdog timer support"
+ depends on WDT
+ help
+ Select this to enable SP805 watchdog timer, which can be found on some
+ nxp layerscape chips.
+
config WDT_CDNS
bool "Cadence watchdog timer support"
depends on WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 19c631bb58..eb285bde24 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
obj-$(CONFIG_WDT_ORION) += orion_wdt.o
obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
obj-$(CONFIG_MPC8xx_WATCHDOG) += mpc8xx_wdt.o
+obj-$(CONFIG_WDT_SP805) += sp805_wdt.o
diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
new file mode 100644
index 0000000000..966128216f
--- /dev/null
+++ b/drivers/watchdog/sp805_wdt.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Watchdog driver for SP805 on some Layerscape SoC
+ *
+ * Copyright 2019 NXP
+ */
+
+#include <asm/io.h>
+#include <common.h>
+#include <dm/device.h>
+#include <dm/fdtaddr.h>
+#include <dm/read.h>
+#include <linux/bitops.h>
+#include <watchdog.h>
+#include <wdt.h>
+
+#define WDTLOAD 0x000
+#define WDTCONTROL 0x008
+#define WDTINTCLR 0x00C
+#define WDTLOCK 0xC00
+
+#define TIME_OUT_MIN_MSECS 1
+#define TIME_OUT_MAX_MSECS 120000
+#define SYS_FSL_WDT_CLK_DIV 16
+#define INT_ENABLE BIT(0)
+#define RESET_ENABLE BIT(1)
+#define DISABLE 0
+#define UNLOCK 0x1ACCE551
+#define LOCK 0x00000001
+#define INT_MASK BIT(0)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct sp805_wdt_priv {
+ void __iomem *reg;
+};
+
+static int sp805_wdt_reset(struct udevice *dev)
+{
+ struct sp805_wdt_priv *priv = dev_get_priv(dev);
+
+ writel(UNLOCK, priv->reg + WDTLOCK);
+ writel(INT_MASK, priv->reg + WDTINTCLR);
+ writel(LOCK, priv->reg + WDTLOCK);
+ readl(priv->reg + WDTLOCK);
+
+ return 0;
+}
+
+static int sp805_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ u32 load_value;
+ u32 load_time;
+ struct sp805_wdt_priv *priv = dev_get_priv(dev);
+
+ load_time = (u32)timeout;
+ if (timeout < TIME_OUT_MIN_MSECS)
+ load_time = TIME_OUT_MIN_MSECS;
+ else if (timeout > TIME_OUT_MAX_MSECS)
+ load_time = TIME_OUT_MAX_MSECS;
+ /* sp805 runs counter with given value twice, so when the max timeout is
+ * set 120s, the gd->bus_clk is less than 1145MHz, the load_value will
+ * not overflow.
+ */
+ load_value = (gd->bus_clk) /
+ (2 * 1000 * SYS_FSL_WDT_CLK_DIV) * load_time;
+
+ writel(UNLOCK, priv->reg + WDTLOCK);
+ writel(load_value, priv->reg + WDTLOAD);
+ writel(INT_MASK, priv->reg + WDTINTCLR);
+ writel(INT_ENABLE | RESET_ENABLE, priv->reg + WDTCONTROL);
+ writel(LOCK, priv->reg + WDTLOCK);
+ readl(priv->reg + WDTLOCK);
+
+ return 0;
+}
+
+static int sp805_wdt_stop(struct udevice *dev)
+{
+ struct sp805_wdt_priv *priv = dev_get_priv(dev);
+
+ writel(UNLOCK, priv->reg + WDTLOCK);
+ writel(DISABLE, priv->reg + WDTCONTROL);
+ writel(LOCK, priv->reg + WDTLOCK);
+ readl(priv->reg + WDTLOCK);
+
+ return 0;
+}
+
+static int sp805_wdt_probe(struct udevice *dev)
+{
+ debug("%s: Probing wdt%u\n", __func__, dev->seq);
+
+ return 0;
+}
+
+static int sp805_wdt_ofdata_to_platdata(struct udevice *dev)
+{
+ struct sp805_wdt_priv *priv = dev_get_priv(dev);
+
+ priv->reg = (void __iomem *)dev_read_addr(dev);
+ if (IS_ERR(priv->reg))
+ return PTR_ERR(priv->reg);
+
+ return 0;
+}
+
+static const struct wdt_ops sp805_wdt_ops = {
+ .start = sp805_wdt_start,
+ .reset = sp805_wdt_reset,
+ .stop = sp805_wdt_stop,
+};
+
+static const struct udevice_id sp805_wdt_ids[] = {
+ { .compatible = "arm,sp805-wdt" },
+ {}
+};
+
+U_BOOT_DRIVER(sp805_wdt) = {
+ .name = "sp805_wdt",
+ .id = UCLASS_WDT,
+ .of_match = sp805_wdt_ids,
+ .probe = sp805_wdt_probe,
+ .priv_auto_alloc_size = sizeof(struct sp805_wdt_priv),
+ .ofdata_to_platdata = sp805_wdt_ofdata_to_platdata,
+ .ops = &sp805_wdt_ops,
+};
--
2.17.1
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