[PATCH 3/3] watchdog: sunxi_wdt: Add support for D1

[Guenter Roeck]

On Sun, Jul 25, 2021 at 10:51:43PM -0500, Samuel Holland wrote:
> D1 adds a key field to the "CFG" and "MODE" registers, that must be set
> to change the other bits. Add logic to set the key when updating those
> registers.
> 
> Signed-off-by: Samuel Holland <samuel at sholland.org>

Reviewed-by: Guenter Roeck <linux at roeck-us.net>

> ---
>  drivers/watchdog/sunxi_wdt.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
> index b50757882a98..6cf82922d3fb 100644
> --- a/drivers/watchdog/sunxi_wdt.c
> +++ b/drivers/watchdog/sunxi_wdt.c
> @@ -48,6 +48,7 @@ struct sunxi_wdt_reg {
>  	u8 wdt_timeout_shift;
>  	u8 wdt_reset_mask;
>  	u8 wdt_reset_val;
> +	u32 wdt_key_val;
>  };
>  
>  struct sunxi_wdt_dev {
> @@ -91,12 +92,14 @@ static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
>  	val = readl(wdt_base + regs->wdt_cfg);
>  	val &= ~(regs->wdt_reset_mask);
>  	val |= regs->wdt_reset_val;
> +	val |= regs->wdt_key_val;
>  	writel(val, wdt_base + regs->wdt_cfg);
>  
>  	/* Set lowest timeout and enable watchdog */
>  	val = readl(wdt_base + regs->wdt_mode);
>  	val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
>  	val |= WDT_MODE_EN;
> +	val |= regs->wdt_key_val;
>  	writel(val, wdt_base + regs->wdt_mode);
>  
>  	/*
> @@ -109,6 +112,7 @@ static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
>  		mdelay(5);
>  		val = readl(wdt_base + regs->wdt_mode);
>  		val |= WDT_MODE_EN;
> +		val |= regs->wdt_key_val;
>  		writel(val, wdt_base + regs->wdt_mode);
>  	}
>  	return 0;
> @@ -141,6 +145,7 @@ static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  	reg = readl(wdt_base + regs->wdt_mode);
>  	reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
>  	reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
> +	reg |= regs->wdt_key_val;
>  	writel(reg, wdt_base + regs->wdt_mode);
>  
>  	sunxi_wdt_ping(wdt_dev);
> @@ -154,7 +159,7 @@ static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
>  	void __iomem *wdt_base = sunxi_wdt->wdt_base;
>  	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
>  
> -	writel(0, wdt_base + regs->wdt_mode);
> +	writel(regs->wdt_key_val, wdt_base + regs->wdt_mode);
>  
>  	return 0;
>  }
> @@ -176,11 +181,13 @@ static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
>  	reg = readl(wdt_base + regs->wdt_cfg);
>  	reg &= ~(regs->wdt_reset_mask);
>  	reg |= regs->wdt_reset_val;
> +	reg |= regs->wdt_key_val;
>  	writel(reg, wdt_base + regs->wdt_cfg);
>  
>  	/* Enable watchdog */
>  	reg = readl(wdt_base + regs->wdt_mode);
>  	reg |= WDT_MODE_EN;
> +	reg |= regs->wdt_key_val;
>  	writel(reg, wdt_base + regs->wdt_mode);
>  
>  	return 0;
> @@ -220,9 +227,20 @@ static const struct sunxi_wdt_reg sun6i_wdt_reg = {
>  	.wdt_reset_val = 0x01,
>  };
>  
> +static const struct sunxi_wdt_reg sun20i_wdt_reg = {
> +	.wdt_ctrl = 0x10,
> +	.wdt_cfg = 0x14,
> +	.wdt_mode = 0x18,
> +	.wdt_timeout_shift = 4,
> +	.wdt_reset_mask = 0x03,
> +	.wdt_reset_val = 0x01,
> +	.wdt_key_val = 0x16aa0000,
> +};
> +
>  static const struct of_device_id sunxi_wdt_dt_ids[] = {
>  	{ .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
>  	{ .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
> +	{ .compatible = "allwinner,sun20i-d1-wdt", .data = &sun20i_wdt_reg },
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);