[U-Boot] [PATCH] driver: watchdog: Add new iMX/LSCH2 WDT driver
Robert Hancock
hancock at sedsystems.ca
Tue Jun 18 15:52:35 UTC 2019
This is a new watchdog timer driver for iMX and LSCH2 using the WDT
framework and driver model. This allows ensuring that U-Boot uses the
same watchdog timer instance and same settings (ex: internal or external
reset) specified in the device tree.
This driver can be used in preference to the old imx_watchdog driver for
boards which have been converted to use the driver model.
Signed-off-by: Robert Hancock <hancock at sedsystems.ca>
---
drivers/watchdog/Kconfig | 14 ++++--
drivers/watchdog/Makefile | 3 ++
drivers/watchdog/imx_wdt.c | 112 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 126 insertions(+), 3 deletions(-)
create mode 100644 drivers/watchdog/imx_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index dbafb74..0e8c8e5 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -27,11 +27,11 @@ config BCM2835_WDT
hardware, with a max timeout of ~15secs.
config IMX_WATCHDOG
- bool "Enable Watchdog Timer support for IMX and LSCH2 of NXP"
+ bool "Enable legacy Watchdog Timer support for IMX and LSCH2 of NXP"
select HW_WATCHDOG
help
- Select this to enable the IMX and LSCH2 of Layerscape watchdog
- driver.
+ Select this to enable the IMX and LSCH2 of Layerscape legacy watchdog
+ driver (not using driver model).
config OMAP_WATCHDOG
bool "TI OMAP watchdog driver"
@@ -109,6 +109,14 @@ config WDT_CDNS
Select this to enable Cadence watchdog timer, which can be found on some
Xilinx Microzed Platform.
+config WDT_IMX
+ bool "iMX/LSCH2 watchdog timer support"
+ depends on WDT && (ARCH_MX25 || ARCH_MX31 || ARCH_MX35 || ARCH_MX5 || ARCH_MX6 || ARCH_MX7 || ARCH_VF610)
+ imply WATCHDOG
+ help
+ Select this to enable the IMX and LSCH2 of Layerscape watchdog
+ driver using driver model.
+
config WDT_MPC8xx
bool "MPC8xx watchdog timer support"
depends on WDT && MPC8xx
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index e3f4fdb..49dd457 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -5,11 +5,13 @@
obj-$(CONFIG_WDT_AT91) += at91sam9_wdt.o
obj-$(CONFIG_FTWDT010_WATCHDOG) += ftwdt010_wdt.o
+ifndef CONFIG_WDT_IMX
ifneq (,$(filter $(SOC), mx25 mx31 mx35 mx5 mx6 mx7 vf610))
obj-y += imx_watchdog.o
else
obj-$(CONFIG_IMX_WATCHDOG) += imx_watchdog.o
endif
+endif
obj-$(CONFIG_S5P) += s5p_wdt.o
obj-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o
obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
@@ -24,6 +26,7 @@ obj-$(CONFIG_WDT_BCM6345) += bcm6345_wdt.o
obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
obj-$(CONFIG_WDT_ORION) += orion_wdt.o
obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
+obj-$(CONFIG_WDT_IMX) += imx_wdt.o
obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o
obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
obj-$(CONFIG_WDT_MTK) += mtk_wdt.o
diff --git a/drivers/watchdog/imx_wdt.c b/drivers/watchdog/imx_wdt.c
new file mode 100644
index 0000000..1b4a5e6
--- /dev/null
+++ b/drivers/watchdog/imx_wdt.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * imx_wdt.c - WDT driver for Freescale/NXP i.MX on-chip watchdog
+ * Copyright (c) 2019 SED Systems, a division of Calian Ltd.
+ *
+ * Based on Linux 4.19 drivers/watchdog/imx2_wdt.c which is:
+ * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang at pengutronix.de>
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <wdt.h>
+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+#include <fsl_wdog.h>
+
+struct imx_wdt_priv {
+ struct watchdog_regs *regs;
+ bool ext_reset;
+};
+
+static int imx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ struct imx_wdt_priv *priv = dev_get_priv(dev);
+ u16 timeout_reg = (timeout / 500) - 1;
+ u16 wcr = WCR_WDZST | WCR_WDBG | WCR_WDE | WCR_SRS |
+ WCR_WDA | SET_WCR_WT(timeout_reg);
+
+ if (priv->ext_reset)
+ wcr |= WCR_WDT;
+
+ debug("%s timeout %llu, wcr %04hX\n", __func__, timeout, wcr);
+
+ writew(wcr, &priv->regs->wcr);
+
+ return 0;
+}
+
+static int imx_wdt_reset(struct udevice *dev)
+{
+ struct imx_wdt_priv *priv = dev_get_priv(dev);
+
+ writew(0x5555, &priv->regs->wsr);
+ writew(0xaaaa, &priv->regs->wsr);
+ return 0;
+}
+
+static int imx_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ struct imx_wdt_priv *priv = dev_get_priv(dev);
+ u16 wcr = WCR_WDE;
+
+ if (priv->ext_reset)
+ wcr |= WCR_SRS; /* do not assert internal reset */
+ else
+ wcr |= WCR_WDA; /* do not assert external reset */
+
+ debug("%s wcr %04hX\n", __func__, wcr);
+
+ /* Write 3 times to ensure it works, due to IMX6Q errata ERR004346 */
+ writew(wcr, &priv->regs->wcr);
+ writew(wcr, &priv->regs->wcr);
+ writew(wcr, &priv->regs->wcr);
+
+ return 0;
+}
+
+static int imx_wdt_ofdata_to_platdata(struct udevice *dev)
+{
+ struct imx_wdt_priv *priv = dev_get_priv(dev);
+
+ priv->regs = devfdt_get_addr_ptr(dev);
+ if (IS_ERR(priv->regs))
+ return PTR_ERR(priv->regs);
+
+ priv->ext_reset = dev_read_bool(dev, "fsl,ext-reset-output");
+
+ debug("%s: ext_reset %d\n", __func__, (int)priv->ext_reset);
+ return 0;
+}
+
+static const struct wdt_ops imx_wdt_ops = {
+ .start = imx_wdt_start,
+ .reset = imx_wdt_reset,
+ .expire_now = imx_wdt_expire_now,
+};
+
+static const struct udevice_id imx_wdt_ids[] = {
+ { .compatible = "fsl,imx21-wdt", },
+ {}
+};
+
+static int imx_wdt_probe(struct udevice *dev)
+{
+ debug("%s() wdt%u\n", __func__, dev->seq);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(imx_wdt) = {
+ .name = "imx_wdt",
+ .id = UCLASS_WDT,
+ .of_match = imx_wdt_ids,
+ .probe = imx_wdt_probe,
+ .priv_auto_alloc_size = sizeof(struct imx_wdt_priv),
+ .ofdata_to_platdata = imx_wdt_ofdata_to_platdata,
+ .ops = &imx_wdt_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
1.8.3.1
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