[PATCH v2] watchdog: add amlogic watchdog support
Stefan Roese
sr at denx.de
Mon Jun 20 16:55:44 CEST 2022
On 13.06.22 16:00, Philippe Boos wrote:
> Add support for hardware watchdog timer for Amlogic SoCs.
> This driver has been heavily inspired by his Linux equivalent
> (meson_gxbb_wdt.c).
>
> Reviewed-by: Jerome Brunet <jbrunet at baylibre.com>
> Reviewed-by: Neil Armstrong <narmstrong at baylibre.com>
>
> Signed-off-by: Philippe Boos <pboos at baylibre.com>
>
Reviewed-by: Stefan Roese <sr at denx.de>
Thanks,
Stefan
> ---
>
> Your recommendations have been implemented. I let you check this version 2.
> The reset works well when triggered by the wdt command in u-boot.
>
> This watchdog driver has been tested on a GXL libretech-cc board and also on
> a custom G12a board. I did the following test cases:
> * boot with a faulty boot command, then we reach watchdog reset successfully,
> * boot a Linux kernel with and without watchdog support, and check if it is
> working as expected.
>
>
> MAINTAINERS | 1 +
> doc/board/amlogic/index.rst | 2 +
> drivers/watchdog/Kconfig | 7 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/meson_gxbb_wdt.c | 136 ++++++++++++++++++++++++++++++
> 5 files changed, 147 insertions(+)
> create mode 100644 drivers/watchdog/meson_gxbb_wdt.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 28e4d38238..ab3ef041f7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -160,6 +160,7 @@ F: drivers/spi/meson_spifc.c
> F: drivers/pinctrl/meson/
> F: drivers/power/domain/meson-gx-pwrc-vpu.c
> F: drivers/video/meson/
> +F: drivers/watchdog/meson_gxbb_wdt.c
> F: include/configs/meson64.h
> F: include/configs/meson64_android.h
> F: doc/board/amlogic/
> diff --git a/doc/board/amlogic/index.rst b/doc/board/amlogic/index.rst
> index 9c7fadf2c0..cc2ba50889 100644
> --- a/doc/board/amlogic/index.rst
> +++ b/doc/board/amlogic/index.rst
> @@ -73,6 +73,8 @@ This matrix concerns the actual source code version.
> +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
> | PCIe (+NVMe) | *N/A* | *N/A* | *N/A* | **Yes** | **Yes** | **Yes** | **Yes** |
> +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
> +| Watchdog | *N/A* | **Yes** | *N/A* | *N/A* | *N/A* | *N/A* | *N/A* |
> ++-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
>
> Boot Documentation
> ------------------
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index c3eb8a8aec..da0fa5396f 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -175,6 +175,13 @@ config WDT_MAX6370
> help
> Select this to enable max6370 watchdog timer.
>
> +config WDT_MESON_GXBB
> + bool "Amlogic watchdog timer support"
> + depends on WDT
> + help
> + Select this to enable Meson watchdog timer,
> + which can be found on some Amlogic platforms.
> +
> config WDT_MPC8xx
> bool "MPC8xx watchdog timer support"
> depends on WDT && MPC8xx
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 1f6199beca..0e2f582a5f 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_WDT_ORION) += orion_wdt.o
> obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
> obj-$(CONFIG_WDT_GPIO) += gpio_wdt.o
> obj-$(CONFIG_WDT_MAX6370) += max6370_wdt.o
> +obj-$(CONFIG_WDT_MESON_GXBB) += meson_gxbb_wdt.o
> obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o
> obj-$(CONFIG_WDT_MT7620) += mt7620_wdt.o
> obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> new file mode 100644
> index 0000000000..6ab005813f
> --- /dev/null
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -0,0 +1,136 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2022 BayLibre, SAS.
> + */
> +
> +#include <clk.h>
> +#include <dm.h>
> +#include <dm/device_compat.h>
> +#include <reset.h>
> +#include <wdt.h>
> +#include <asm/io.h>
> +#include <linux/bitops.h>
> +
> +#define GXBB_WDT_CTRL_REG 0x0
> +#define GXBB_WDT_TCNT_REG 0x8
> +#define GXBB_WDT_RSET_REG 0xc
> +
> +#define GXBB_WDT_CTRL_SYS_RESET_NOW BIT(26)
> +#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
> +#define GXBB_WDT_CTRL_CLK_EN BIT(24)
> +#define GXBB_WDT_CTRL_EE_RESET BIT(21)
> +#define GXBB_WDT_CTRL_EN BIT(18)
> +
> +#define GXBB_WDT_CTRL_DIV_MASK GENMASK(17, 0)
> +#define GXBB_WDT_TCNT_SETUP_MASK GENMASK(15, 0)
> +
> +
> +struct amlogic_wdt_priv {
> + void __iomem *reg_base;
> +};
> +
> +static int amlogic_wdt_set_timeout(struct udevice *dev, u64 timeout_ms)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> +
> + if (timeout_ms > GXBB_WDT_TCNT_SETUP_MASK) {
> + dev_warn(dev, "%s: timeout_ms=%llu: maximum watchdog timeout exceeded\n",
> + __func__, timeout_ms);
> + timeout_ms = GXBB_WDT_TCNT_SETUP_MASK;
> + }
> +
> + writel(timeout_ms, data->reg_base + GXBB_WDT_TCNT_REG);
> +
> + return 0;
> +}
> +
> +static int amlogic_wdt_stop(struct udevice *dev)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> +
> + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> +
> + return 0;
> +}
> +
> +static int amlogic_wdt_start(struct udevice *dev, u64 time_ms, ulong flags)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> +
> + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> +
> + return amlogic_wdt_set_timeout(dev, time_ms);
> +}
> +
> +static int amlogic_wdt_reset(struct udevice *dev)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> +
> + writel(0, data->reg_base + GXBB_WDT_RSET_REG);
> +
> + return 0;
> +}
> +
> +static int amlogic_wdt_expire_now(struct udevice *dev, ulong flags)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> +
> + writel(0, data->reg_base + GXBB_WDT_CTRL_SYS_RESET_NOW);
> +
> + return 0;
> +}
> +
> +static int amlogic_wdt_probe(struct udevice *dev)
> +{
> + struct amlogic_wdt_priv *data = dev_get_priv(dev);
> + int ret;
> +
> + data->reg_base = dev_remap_addr(dev);
> + if (!data->reg_base)
> + return -EINVAL;
> +
> + struct clk clk;
> +
> + ret = clk_get_by_index(dev, 0, &clk);
> + if (ret)
> + return ret;
> +
> + ret = clk_enable(&clk);
> + if (ret) {
> + clk_free(&clk);
> + return ret;
> + }
> +
> + /* Setup with 1ms timebase */
> + writel(((clk_get_rate(&clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
> + GXBB_WDT_CTRL_EE_RESET |
> + GXBB_WDT_CTRL_CLK_EN |
> + GXBB_WDT_CTRL_CLKDIV_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> +
> + return 0;
> +}
> +
> +static const struct wdt_ops amlogic_wdt_ops = {
> + .start = amlogic_wdt_start,
> + .reset = amlogic_wdt_reset,
> + .stop = amlogic_wdt_stop,
> + .expire_now = amlogic_wdt_expire_now,
> +};
> +
> +static const struct udevice_id amlogic_wdt_ids[] = {
> + { .compatible = "amlogic,meson-gxbb-wdt" },
> + {}
> +};
> +
> +U_BOOT_DRIVER(amlogic_wdt) = {
> + .name = "amlogic_wdt",
> + .id = UCLASS_WDT,
> + .of_match = amlogic_wdt_ids,
> + .priv_auto = sizeof(struct amlogic_wdt_priv),
> + .probe = amlogic_wdt_probe,
> + .ops = &amlogic_wdt_ops,
> + .flags = DM_FLAG_PRE_RELOC,
> +};
Viele Grüße,
Stefan Roese
--
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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