[U-Boot] [PATCH] wait_bit: add big endian version of wait_for_bit function

Tom Rini trini at konsulko.com
Mon Jan 1 13:41:02 UTC 2018


On Sat, Dec 30, 2017 at 11:12:36AM +0100, Álvaro Fernández Rojas wrote:

> The only difference with the existing wait_for_bit function is the fact that
> wait_for_bit_be expects the register size to be read.
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
> ---
>  include/wait_bit.h | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 69 insertions(+)
> 
> diff --git a/include/wait_bit.h b/include/wait_bit.h
> index 06ad43a122..828fdcda02 100644
> --- a/include/wait_bit.h
> +++ b/include/wait_bit.h
> @@ -69,5 +69,74 @@ static inline int wait_for_bit(const char *prefix, const u32 *reg,
>  	return -ETIMEDOUT;
>  }
>  
> +/**
> + * wait_for_bit_be()	waits for bit set/cleared in BE register
> + *
> + * Function polls register waiting for specific bit(s) change
> + * (either 0->1 or 1->0). It can fail under two conditions:
> + * - Timeout
> + * - User interaction (CTRL-C)
> + * Function succeeds only if all bits of masked register are set/cleared
> + * (depending on set option).
> + *
> + * @param prefix	Prefix added to timeout messagge (message visible only
> + *			with debug enabled)
> + * @param reg		Register that will be read (using read_be())
> + * @param size		Size of the register that will be read
> + * @param mask		Bit(s) of register that must be active
> + * @param set		Selects wait condition (bit set or clear)
> + * @param timeout_ms	Timeout (in miliseconds)
> + * @param breakable	Enables CTRL-C interruption
> + * @return		0 on success, -EINVAL, -ETIMEDOUT or -EINTR on failure
> + */
> +static inline int wait_for_bit_be(const char *prefix,
> +				  const u32 *reg, const u8 size,
> +				  const u32 mask, const bool set,
> +				  const unsigned int timeout_ms,
> +				  const bool breakable)
> +{
> +	u32 val;
> +	unsigned long start = get_timer(0);
> +
> +	while (1) {
> +		switch(size)
> +		{
> +			case 8:
> +				val = readb_be(reg);
> +				break;
> +			case 16:
> +				val = readw_be(reg);
> +				break;
> +			case 32:
> +				val = readl_be(reg);
> +				break;
> +			default:
> +				debug("%s: invalid size %u\n", prefix, size);
> +				return -EINVAL;
> +		}
> +
> +		if (!set)
> +			val = ~val;
> +
> +		if ((val & mask) == mask)
> +			return 0;
> +
> +		if (get_timer(start) > timeout_ms)
> +			break;
> +
> +		if (breakable && ctrlc()) {
> +			puts("Abort\n");
> +			return -EINTR;
> +		}
> +
> +		udelay(1);
> +		WATCHDOG_RESET();
> +	}
> +
> +	debug("%s: Timeout (reg=%p mask=%08x wait_set=%i)\n", prefix, reg, mask,
> +	      set);
> +
> +	return -ETIMEDOUT;
> +}

Where is this used?  Thanks!

-- 
Tom
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