[PATCH u-boot-mvebu] watchdog: armada_37xx: Probe driver also when watchdog is already running

[Stefan Roese]

On 2/23/22 14:21, Pali Rohár wrote:
> If Armada 37xx watchdog is started before U-Boot then CNTR_CTRL_ACTIVE bit
> is set, U-Boot armada-37xx-wdt.c driver fails to initialize and so U-Boot
> is unable to use or kick this watchdog.
> 
> Do not check for CNTR_CTRL_ACTIVE bit and always initialize watchdog. Same
> behavior is implemented in Linux kernel driver.
> 
> This change allows to activate watchdog in firmware which loads U-Boot.
> 
> Signed-off-by: Pali Rohár <pali at kernel.org>

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan

> ---
>   drivers/watchdog/armada-37xx-wdt.c | 17 +++--------------
>   1 file changed, 3 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/watchdog/armada-37xx-wdt.c b/drivers/watchdog/armada-37xx-wdt.c
> index 2e119b9b5aad..bacebbc7926a 100644
> --- a/drivers/watchdog/armada-37xx-wdt.c
> +++ b/drivers/watchdog/armada-37xx-wdt.c
> @@ -58,13 +58,11 @@ static void counter_disable(struct a37xx_wdt *priv, int id)
>   	clrbits_le32(priv->reg + CNTR_CTRL(id), CNTR_CTRL_ENABLE);
>   }
>   
> -static int init_counter(struct a37xx_wdt *priv, int id, u32 mode, u32 trig_src)
> +static void init_counter(struct a37xx_wdt *priv, int id, u32 mode, u32 trig_src)
>   {
>   	u32 reg;
>   
>   	reg = readl(priv->reg + CNTR_CTRL(id));
> -	if (reg & CNTR_CTRL_ACTIVE)
> -		return -EBUSY;
>   
>   	reg &= ~(CNTR_CTRL_MODE_MASK | CNTR_CTRL_PRESCALE_MASK |
>   		 CNTR_CTRL_TRIG_SRC_MASK);
> @@ -79,8 +77,6 @@ static int init_counter(struct a37xx_wdt *priv, int id, u32 mode, u32 trig_src)
>   	reg |= trig_src;
>   
>   	writel(reg, priv->reg + CNTR_CTRL(id));
> -
> -	return 0;
>   }
>   
>   static int a37xx_wdt_reset(struct udevice *dev)
> @@ -116,16 +112,9 @@ static int a37xx_wdt_expire_now(struct udevice *dev, ulong flags)
>   static int a37xx_wdt_start(struct udevice *dev, u64 ms, ulong flags)
>   {
>   	struct a37xx_wdt *priv = dev_get_priv(dev);
> -	int err;
> -
> -	err = init_counter(priv, 0, CNTR_CTRL_MODE_ONESHOT, 0);
> -	if (err < 0)
> -		return err;
>   
> -	err = init_counter(priv, 1, CNTR_CTRL_MODE_HWSIG,
> -			   CNTR_CTRL_TRIG_SRC_PREV_CNTR);
> -	if (err < 0)
> -		return err;
> +	init_counter(priv, 0, CNTR_CTRL_MODE_ONESHOT, 0);
> +	init_counter(priv, 1, CNTR_CTRL_MODE_HWSIG, CNTR_CTRL_TRIG_SRC_PREV_CNTR);
>   
>   	priv->timeout = ms * priv->clk_rate / 1000 / CNTR_CTRL_PRESCALE_MIN;
>   

Viele Grüße,
Stefan Roese

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