Re: [PATCH u-boot v2 1/2] drivers: spi: Add support for disabling FMC_WDT2 for aspeed

[Andrew Jeffery <andrew@codeconstruct.com.au>]

On Tue, 2025-12-02 at 15:52 -0800, Marc Olberding wrote:
> Adds support for disabling the ast2600 FMC_WDT2 through
> a device tree entry in the fmc node.
> Set `aspeed,watchdog-disable` in your device tree to have
> the driver disable it.
> 
> Signed-off-by: Marc Olberding <molberding@nvidia.com>
> ---
>  drivers/spi/aspeed_spi.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/spi/aspeed_spi.c b/drivers/spi/aspeed_spi.c
> index 54520122f1c48c8b2052b4b1e47445a9b990d25e..de954e477aa15e6d1be042a2aee47f5a501178da 100644
> --- a/drivers/spi/aspeed_spi.c
> +++ b/drivers/spi/aspeed_spi.c
> @@ -30,14 +30,16 @@ struct aspeed_spi_regs {
>  					/* 0x30 .. 0x38 Segment Address */
>  	u32 _reserved1[5];		/* .. */
>  	u32 soft_rst_cmd_ctrl;	/* 0x50 Auto Soft-Reset Command Control */
> -	u32 _reserved2[11];		/* .. */
> +	u32 _reserved2[4];		/* .. */
> +	u32 wdt2_ctrl;			/* 0x64 FMC_WDT2 control */
> +	u32 _reserved3[6];		/* .. */

Ugh (passing commentary, not your fault).

>  	u32 dma_ctrl;			/* 0x80 DMA Control/Status */
>  	u32 dma_flash_addr;		/* 0x84 DMA Flash Side Address */
>  	u32 dma_dram_addr;		/* 0x88 DMA DRAM Side Address */
>  	u32 dma_len;			/* 0x8c DMA Length Register */
>  	u32 dma_checksum;		/* 0x90 Checksum Calculation Result */
>  	u32 timings;			/* 0x94 Read Timing Compensation */
> -	u32 _reserved3[1];
> +	u32 _reserved4[1];
>  	/* not used */
>  	u32 soft_strap_status;		/* 0x9c Software Strap Status */
>  	u32 write_cmd_filter_ctrl;	/* 0xa0 Write Command Filter Control */
> @@ -45,7 +47,7 @@ struct aspeed_spi_regs {
>  	u32 lock_ctrl_reset;		/* 0xa8 Lock Control (SRST#) */
>  	u32 lock_ctrl_wdt;		/* 0xac Lock Control (Watchdog) */
>  	u32 write_addr_filter[8];	/* 0xb0 Write Address Filter */
> -	u32 _reserved4[12];
> +	u32 _reserved5[12];
>  	u32 fully_qualified_cmd[20];	/* 0x100 Fully Qualified Command */
>  	u32 addr_qualified_cmd[12];	/* 0x150 Address Qualified Command */
>  };
> @@ -163,7 +165,8 @@ struct aspeed_spi_regs {
>  #define SPI_3B_AUTO_CLR_REG   0x1e6e2510
>  #define SPI_3B_AUTO_CLR       BIT(9)
>  
> -
> +/* FMC_WDT2 control register */
> +#define WDT2_ENABLE		BIT(0)
>  /*
>   * flash related info
>   */
> @@ -267,6 +270,7 @@ struct aspeed_spi_priv {
>  	ulong hclk_rate; /* AHB clock rate */
>  	u8 num_cs;
>  	bool is_fmc;
> +	bool disable_wdt;
>  
>  	struct aspeed_spi_flash flashes[ASPEED_SPI_MAX_CS];
>  	u32 flash_count;
> @@ -683,6 +687,9 @@ static int aspeed_spi_controller_init(struct aspeed_spi_priv *priv)
>  	setbits_le32(&priv->regs->conf,
>  		     CONF_ENABLE_W2 | CONF_ENABLE_W1 | CONF_ENABLE_W0);
>  
> +	if (priv->is_fmc && priv->disable_wdt)
> +		clrbits_le32(&priv->regs->wdt2_ctrl, WDT2_ENABLE);
> +
>  	/*
>  	 * Set safe default settings for each device. These will be
>  	 * tuned after the SPI flash devices are probed.
> @@ -1907,6 +1914,10 @@ static int aspeed_spi_probe(struct udevice *bus)
>  	 * SPI controllers
>  	 */
>  	priv->is_fmc = dev_get_driver_data(bus);
> +	if (device_is_compatible(bus, "aspeed,ast2600-fmc") &&
> +	    dev_read_bool(bus, "aspeed,watchdog-disable"))
> +		priv->disable_wdt = true;

We're not setting it to false, just declaring it above, which means if
this branch isn't taken then its value is undefined.

Perhaps initialise it to false by default.

> +

Unnecessary new-line?

>  
>  	ret = aspeed_spi_controller_init(priv);
>  	if (ret)