[U-Boot] [PATCH v1] watchdog: Introduce watchdog driver for Intel Tangier

[Lukasz Majewski <lukma@denx.de>]

Hi Andy,

> From: Felipe Balbi <felipe.balbi@linux.intel.com>
> 
> Add watchdog driver for Intel Tangier based platforms.
> 
> Signed-off-by: Vincent Tinelli <vincent.tinelli@intel.com>
> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  common/board_f.c               |  1 +
>  drivers/watchdog/Kconfig       |  8 ++++++
>  drivers/watchdog/Makefile      |  1 +
>  drivers/watchdog/tangier_wdt.c | 63
> ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 73
> insertions(+) create mode 100644 drivers/watchdog/tangier_wdt.c
> 
> diff --git a/common/board_f.c b/common/board_f.c
> index d9431ee79a..ad1eae98a5 100644
> --- a/common/board_f.c
> +++ b/common/board_f.c
> @@ -91,6 +91,7 @@ static int init_func_watchdog_init(void)
>  	(defined(CONFIG_M68K) || defined(CONFIG_MICROBLAZE) || \
>  	defined(CONFIG_SH) || defined(CONFIG_AT91SAM9_WATCHDOG) || \
>  	defined(CONFIG_DESIGNWARE_WATCHDOG) || \
> +	defined(CONFIG_TANGIER_WATCHDOG) || \
>  	defined(CONFIG_IMX_WATCHDOG))

I have stumbled upon similar patch... There should be new Kconfig
option created and enabled in required SoCs.

>  	hw_watchdog_init();
>  	puts("       Watchdog enabled\n");
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index dbdaafc149..66fe70dba1 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1,5 +1,13 @@
>  menu "WATCHDOG support"
>  
> +config TANGIER_WATCHDOG
> +	bool "Intel Tangier watchdog"
> +	depends on INTEL_MID
> +	help
> +	  This enables support for watchdog controller available on
> +	  Intel Tangier SoC. If you're using a board with Intel
> Tangier
> +	  SoC, say Y here.
> +
>  config ULP_WATCHDOG
>  	bool "i.MX7ULP watchdog"
>  	help
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index dea18363ca..7b77d8379f 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -15,4 +15,5 @@ obj-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o
>  obj-$(CONFIG_BFIN_WATCHDOG)  += bfin_wdt.o
>  obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
>  obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o
> +obj-$(CONFIG_TANGIER_WATCHDOG) += tangier_wdt.o
>  obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o
> diff --git a/drivers/watchdog/tangier_wdt.c
> b/drivers/watchdog/tangier_wdt.c new file mode 100644
> index 0000000000..23be71a42f
> --- /dev/null
> +++ b/drivers/watchdog/tangier_wdt.c
> @@ -0,0 +1,63 @@
> +/*
> + * Copyright (c) 2017 Intel Corporation
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +#include <common.h>
> +#include <watchdog.h>
> +#include <asm/scu.h>
> +
> +/* Hardware timeout in seconds */
> +#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
> +#define WATCHDOG_HEARTBEAT 60000
> +#else
> +#define WATCHDOG_HEARTBEAT CONFIG_WATCHDOG_TIMEOUT_MSECS
> +#endif
> +
> +enum {
> +	SCU_WATCHDOG_START			= 0,
> +	SCU_WATCHDOG_STOP			= 1,
> +	SCU_WATCHDOG_KEEPALIVE			= 2,
> +	SCU_WATCHDOG_SET_ACTION_ON_TIMEOUT	= 3,
> +};
> +
> +void hw_watchdog_reset(void)
> +{
> +	static unsigned long prev;
> +	unsigned long now;
> +
> +	if (gd->timer)
> +		now = timer_get_us();
> +	else
> +		now = rdtsc() / 1000000;
> +
> +	/* Do not flood SCU */
> +	if (unlikely((now - prev) > (WATCHDOG_HEARTBEAT * 1000))) {
> +		prev = now;
> +		scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER,
> SCU_WATCHDOG_KEEPALIVE);
> +	}
> +}
> +
> +int hw_watchdog_disable(void)
> +{
> +	return scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER,
> SCU_WATCHDOG_STOP); +}
> +
> +void hw_watchdog_init(void)
> +{
> +	u32 timeout = WATCHDOG_HEARTBEAT / 1000;
> +	int in_size;
> +	struct ipc_wd_start {
> +		u32 pretimeout;
> +		u32 timeout;
> +	} ipc_wd_start = { timeout, timeout };
> +
> +	/*
> +	 * SCU expects the input size for watchdog IPC
> +	 * to be based on 4 bytes
> +	 */
> +	in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
> +
> +	scu_ipc_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_START,
> +			(u32 *)&ipc_wd_start, in_size, NULL, 0);
> +}

The code seems OK, but recently patches to add wdt-uclass has been
posted:

http://patchwork.ozlabs.org/patch/751448/
http://patchwork.ozlabs.org/patch/751451/

Maybe it would be better to port this driver to the uclass from the
very beginning?


Best regards,

Lukasz Majewski

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