[u-boot][PATCH 2/2] spi: atmel-quadspi: Add verbose debug facilities to monitor register accesses

[Tudor.Ambarus at microchip.com]

On Friday, March 20, 2020 11:37:59 AM EET Tudor.Ambarus at microchip.com wrote:
> From: Tudor Ambarus <tudor.ambarus at microchip.com>
> 
> This feature should not be enabled in release but can be useful for
> developers who need to monitor register accesses at some specific places.
> 
> Helped me identify a bug in u-boot, by comparing the register accesses
> from the u-boot driver with the ones from its linux variant.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus at microchip.com>
> ---
>  drivers/spi/atmel-quadspi.c | 114 ++++++++++++++++++++++++++++++------
>  1 file changed, 96 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
> index 4099ee87993d..3de367e6a0c8 100644
> --- a/drivers/spi/atmel-quadspi.c
> +++ b/drivers/spi/atmel-quadspi.c
> @@ -148,6 +148,7 @@ struct atmel_qspi {
>  	void __iomem *mem;
>  	resource_size_t mmap_size;
>  	const struct atmel_qspi_caps *caps;
> +	struct udevice *dev;
>  	ulong bus_clk_rate;
>  	u32 mr;
>  };
> @@ -169,6 +170,81 @@ static const struct atmel_qspi_mode atmel_qspi_modes[]
> = { { 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
>  };
> 
> +#ifdef VERBOSE_DEBUG
> +static const char *atmel_qspi_reg_name(u32 offset, char *tmp, size_t sz)
> +{
> +	switch (offset) {
> +	case QSPI_CR:
> +		return "CR";
> +	case QSPI_MR:
> +		return "MR";
> +	case QSPI_RD:
> +		return "MR";
> +	case QSPI_TD:
> +		return "TD";
> +	case QSPI_SR:
> +		return "SR";
> +	case QSPI_IER:
> +		return "IER";
> +	case QSPI_IDR:
> +		return "IDR";
> +	case QSPI_IMR:
> +		return "IMR";
> +	case QSPI_SCR:
> +		return "SCR";
> +	case QSPI_IAR:
> +		return "IAR";
> +	case QSPI_ICR:
> +		return "ICR/WICR";
> +	case QSPI_IFR:
> +		return "IFR";
> +	case QSPI_RICR:
> +		return "RICR";
> +	case QSPI_SMR:
> +		return "SMR";
> +	case QSPI_SKR:
> +		return "SKR";
> +	case QSPI_WPMR:
> +		return "WPMR";
> +	case QSPI_WPSR:
> +		return "WPSR";
> +	case QSPI_VERSION:
> +		return "VERSION";
> +	default:
> +		snprintf(tmp, sz, "0x%02x", offset);
> +		break;
> +	}
> +
> +	return tmp;
> +}
> +#endif /* VERBOSE_DEBUG */
> +
> +static u32 atmel_qspi_read(struct atmel_qspi *aq, u32 offset)
> +{
> +	u32 value = readl(aq->regs + offset);
> +
> +#ifdef VERBOSE_DEBUG
> +	char tmp[8];

The largest string that I print is "ICR/WICR" which is 8bytes, but I didn't 
count the trailing null space, so the array should better be increased to 16 
bytes, to avoid truncation.

> +
> +	dev_vdbg(aq->dev, "read 0x%08x from %s\n", value,
> +		 atmel_qspi_reg_name(offset, tmp, sizeof(tmp)));
> +#endif /* VERBOSE_DEBUG */
> +
> +	return value;
> +}
> +
> +static void atmel_qspi_write(u32 value, struct atmel_qspi *aq, u32 offset)
> +{
> +#ifdef VERBOSE_DEBUG
> +	char tmp[8];

ditto

Jagan, if the rest looks good, would you do this change when applying? Let me 
know if I have to resubmit, or if there are any suggestions.

Cheers,
ta