[PATCH v2] watchdog: add amlogic watchdog support
Neil Armstrong
narmstrong at baylibre.com
Tue Jun 21 11:17:44 CEST 2022
Hi Stefan,
On 20/06/2022 16:55, Stefan Roese wrote:
> 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>
Should I take it into my tree ?
Thanks,
Neil
>
> 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
>
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