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

Andrew Jeffery
2025-12-16T23:23:41Z

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)