[U-Boot] [PATCH] driver: watchdog: Add new iMX/LSCH2 WDT driver
Stefan Roese
sr at denx.de
Wed Jun 19 05:32:41 UTC 2019
Hi Robert,
(Cc'ing Marek and Heiko)
On 18.06.19 17:52, Robert Hancock wrote:
> 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>
Marek just recently added DM (WDT) support to the imx driver:
https://patchwork.ozlabs.org/patch/1112591/
https://patchwork.ozlabs.org/patch/1112592/
Please take a look at this driver.
Thanks,
Stefan
> ---
> 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,
> +};
>
Viele Grüße,
Stefan
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de
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