[PATCH v1 01/22] wdt: imx8qxp: add option to control external PMIC wdt via IMX8 SCU

Stefan Roese sr at denx.de
Fri Nov 8 08:19:06 CET 2024


Hi Heiko,

On 11/8/24 06:21, Heiko Schocher wrote:
> control the watchdog in the PMIC through SCU.

A few more details would be good here (please see below).

> Signed-off-by: Andrej Valek <andrej.valek at siemens.com>
> Signed-off-by: Heiko Schocher <hs at denx.de>
> ---
> 
>   drivers/misc/imx8/scu_api.c    | 21 ++++++++++++++
>   drivers/watchdog/Kconfig       |  7 +++++
>   drivers/watchdog/Makefile      |  1 +
>   drivers/watchdog/scu_wdt.c     | 52 ++++++++++++++++++++++++++++++++++
>   include/firmware/imx/sci/rpc.h |  1 +
>   include/firmware/imx/sci/sci.h |  1 +
>   6 files changed, 83 insertions(+)
>   create mode 100644 drivers/watchdog/scu_wdt.c
> 
> diff --git a/drivers/misc/imx8/scu_api.c b/drivers/misc/imx8/scu_api.c
> index 591d71b096a..edb6923151a 100644
> --- a/drivers/misc/imx8/scu_api.c
> +++ b/drivers/misc/imx8/scu_api.c
> @@ -951,6 +951,27 @@ int sc_timer_set_wdog_window(sc_ipc_t ipc, sc_timer_wdog_time_t window)
>   	return ret;
>   }
>   
> +int sc_timer_control_pmic_wdog(sc_ipc_t ipc, u8 cmd)
> +{
> +	struct udevice *dev = gd->arch.scu_dev;
> +	struct sc_rpc_msg_s msg;
> +	int size = sizeof(struct sc_rpc_msg_s);
> +	int ret;
> +
> +	RPC_VER(&msg) = SC_RPC_VERSION;
> +	RPC_SVC(&msg) = (u8)SC_RPC_SVC_TIMER;
> +	RPC_FUNC(&msg) = (u8)TIMER_FUNC_CTRL_PMIC_WDOG;
> +	RPC_U8(&msg, 0U) = (u8)cmd;
> +	RPC_SIZE(&msg) = 2U;
> +
> +	ret = misc_call(dev, SC_FALSE, &msg, size, &msg, size);
> +	if (ret)
> +		printf("%s: res:%d\n",
> +		       __func__, RPC_R8(&msg));

Nitpicking: Does the printf statement above fit into one line?

> +
> +	return ret;
> +}
> +
>   int sc_seco_authenticate(sc_ipc_t ipc, sc_seco_auth_cmd_t cmd,
>   			 sc_faddr_t addr)
>   {
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 0e45f0a0922..eb9e75abe48 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -428,6 +428,13 @@ config WDT_ARM_SMC
>   	  Select this to enable Arm SMC watchdog timer. This watchdog will manage
>   	  a watchdog based on ARM SMCCC communication.
>   
> +config WDT_IMX_SCU
> +	bool "Enable external Watchdog Timer support for IMX"
> +	depends on IMX8 && WDT
> +	help
> +	  Select this to enable the external IMX watchdog driver
> +	  controlled via IMX8 SCU.

I don't know the details here, but what exactly is "external" here?
If it's still inside the i.MX then external sounds a bit misleading.

> +
>   config SPL_WDT
>   	bool "Enable driver model for watchdog timer drivers in SPL"
>   	depends on SPL_DM
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 0b107c008f7..e943b904bae 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -33,6 +33,7 @@ obj-$(CONFIG_WDT_DA9063) += da9063-wdt.o
>   obj-$(CONFIG_WDT_DAVINCI) += davinci_wdt.o
>   obj-$(CONFIG_WDT_FTWDT010) += ftwdt010_wdt.o
>   obj-$(CONFIG_$(SPL_TPL_)WDT_GPIO) += gpio_wdt.o
> +obj-$(CONFIG_WDT_IMX_SCU) += scu_wdt.o

Perhaps better to add some "imx" to the source file name?

>   obj-$(CONFIG_WDT_MAX6370) += max6370_wdt.o
>   obj-$(CONFIG_WDT_MCF) += mcf_wdt.o
>   obj-$(CONFIG_WDT_MESON_GXBB) += meson_gxbb_wdt.o
> diff --git a/drivers/watchdog/scu_wdt.c b/drivers/watchdog/scu_wdt.c
> new file mode 100644
> index 00000000000..ad8766dc132
> --- /dev/null
> +++ b/drivers/watchdog/scu_wdt.c
> @@ -0,0 +1,52 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <dm.h>
> +#include <wdt.h>
> +#include <firmware/imx/sci/sci.h>
> +
> +/* watchdog commands */
> +#define CMD_START_WDT 0x55
> +#define CMD_STOP_WDT  0x45
> +#define CMD_PING_WDT  0x35
> +
> +static int scu_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
> +{
> +	/* start external watchdog via Timer API */
> +	return sc_timer_control_pmic_wdog(-1, CMD_START_WDT);
> +}
> +
> +static int scu_wdt_stop(struct udevice *dev)
> +{
> +	/* stop external watchdog via Timer API */
> +	return sc_timer_control_pmic_wdog(-1, CMD_STOP_WDT);
> +}
> +
> +static int scu_wdt_reset(struct udevice *dev)
> +{
> +	return sc_timer_control_pmic_wdog(-1, CMD_PING_WDT);
> +}
> +
> +static int scu_wdt_probe(struct udevice *dev)
> +{
> +	debug("%s(dev=%p)\n", __func__, dev);
> +	return 0;
> +}
> +
> +static const struct wdt_ops scu_wdt_ops = {
> +	.reset		= scu_wdt_reset,
> +	.start		= scu_wdt_start,
> +	.stop		= scu_wdt_stop,
> +};
> +
> +static const struct udevice_id scu_wdt_ids[] = {
> +	{ .compatible = "siemens,scu-wdt" },

Really siemens specific? Is this also available in Linux btw?
Looking into the Linux source, is this driver somehow related to
this one:

drivers/watchdog/imx_sc_wdt.c ?

Thanks,
Stefan

> +	{ }
> +};
> +
> +U_BOOT_DRIVER(scu_wdt) = {
> +	.name		= "scu_wdt",
> +	.id		= UCLASS_WDT,
> +	.of_match	= scu_wdt_ids,
> +	.probe		= scu_wdt_probe,
> +	.ops		= &scu_wdt_ops,
> +};
> diff --git a/include/firmware/imx/sci/rpc.h b/include/firmware/imx/sci/rpc.h
> index 28adec2a8e1..9470f9e7178 100644
> --- a/include/firmware/imx/sci/rpc.h
> +++ b/include/firmware/imx/sci/rpc.h
> @@ -230,5 +230,6 @@ struct sc_rpc_msg_s {
>   #define TIMER_FUNC_SET_SYSCTR_ALARM 16U /* Index for sc_timer_set_sysctr_alarm() RPC call */
>   #define TIMER_FUNC_SET_SYSCTR_PERIODIC_ALARM 17U /* Index for sc_timer_set_sysctr_periodic_alarm() RPC call */
>   #define TIMER_FUNC_CANCEL_SYSCTR_ALARM 18U /* Index for sc_timer_cancel_sysctr_alarm() RPC call */
> +#define TIMER_FUNC_CTRL_PMIC_WDOG 20U  /*!< Index for sc_timer_ctrl_pmic_wdog() RPC call */
>   
>   #endif /* SC_RPC_H */
> diff --git a/include/firmware/imx/sci/sci.h b/include/firmware/imx/sci/sci.h
> index 7d8499f070a..b971b62836d 100644
> --- a/include/firmware/imx/sci/sci.h
> +++ b/include/firmware/imx/sci/sci.h
> @@ -123,6 +123,7 @@ int sc_rm_set_master_sid(sc_ipc_t ipc, sc_rsrc_t resource, sc_rm_sid_t sid);
>   
>   /* Timer API */
>   int sc_timer_set_wdog_window(sc_ipc_t ipc, sc_timer_wdog_time_t window);
> +int sc_timer_control_pmic_wdog(sc_ipc_t ipc, u8 cmd);
>   
>   /* SECO API */
>   int sc_seco_authenticate(sc_ipc_t ipc, sc_seco_auth_cmd_t cmd,

Viele Grüße,
Stefan Roese

-- 
DENX Software Engineering GmbH,      Managing Director: Erika Unter
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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