Re: [PATCH 1/3] mtd: nand: pxa3xx_nand: add register access debug

Brian Norris
2016-01-07T00:06:34Z

On Tue, Aug 11, 2015 at 09:57:12PM +0200, Robert Jarzmik wrote:
> Add verbose debug for register accesses. This enables easier debugging
> by following where and how hardware is stimulated, and how it answers.
>
> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
> ---
> drivers/mtd/nand/pxa3xx_nand.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index 1259cc558ce9..ed44bddcc43f 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -127,11 +127,23 @@
> #define EXT_CMD_TYPE_MONO 0 /* Monolithic read/write */
>
> /* macros for registers read/write */
> -#define nand_writel(info, off, val) \
> - writel_relaxed((val), (info)->mmio_base + (off))
> -
> -#define nand_readl(info, off) \
> - readl_relaxed((info)->mmio_base + (off))
> +#define nand_writel(info, off, val) \
> + do { \
> + dev_vdbg(&info->pdev->dev, \
> + "%s():%d nand_writel(0x%x, %s)\n", \
> + __func__, __LINE__, (val), #off); \

The stringification of 'off' works for now, but I think that'd be a bit
restrictive in the future, if we ever want to (e.g.) do arithmetic to
compute the offset, like:

nand_writel(info, SOME_REGISTER_MACRO + idx * 4, foo);

You might be better off just printing the hex value of the offset.

Regards,
Brian

> + writel_relaxed((val), (info)->mmio_base + (off)); \
> + } while (0)
> +
> +#define nand_readl(info, off) \
> + ({ \
> + unsigned int _v; \
> + _v = readl_relaxed((info)->mmio_base + (off)); \
> + dev_vdbg(&info->pdev->dev, \
> + "%s():%d nand_readl(%s): 0x%x\n", \
> + __func__, __LINE__, #off, _v); \
> + _v; \
> + })
>
> /* error code and state */
> enum {
> --
> 2.1.4
>