On Wed, Apr 15, 2020 at 11:29:13AM +0200, Ahmad Fatoum wrote:
> The sdhci_readN accessors don't lend themselves for clean use with
> readx_poll_timeout because they accept two arguments. Add
> a sdhci-specific helper, so the sdhci drivers can cut down on the
> timeout loop boilerplate.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> drivers/mci/sdhci.h | 51 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/drivers/mci/sdhci.h b/drivers/mci/sdhci.h
> index a307dc97cd9a..7ac32f1541b8 100644
> --- a/drivers/mci/sdhci.h
> +++ b/drivers/mci/sdhci.h
> @@ -1,6 +1,8 @@
> #ifndef __MCI_SDHCI_H
> #define __MCI_SDHCI_H
>
> +#include <pbl.h>
> +
> #define SDHCI_DMA_ADDRESS 0x00
> #define SDHCI_BLOCK_SIZE__BLOCK_COUNT 0x04
> #define SDHCI_BLOCK_SIZE 0x04
> @@ -144,4 +146,53 @@ void sdhci_set_cmd_xfer_mode(struct sdhci *host, struct mci_cmd *cmd,
> u32 *xfer);
> int sdhci_transfer_data(struct sdhci *sdhci, struct mci_data *data);
>
> +/**
> + * sdhci_readx_poll_timeout - Periodically poll an sdhci register until
> + * a condition is met or a timeout occurs
> + * @bits: access width
> + * @sdhci: sdhci instance
> + * @reg: Register to poll
> + * @val: Variable to read the value into
> + * @cond: Break condition (usually involving @val)
> + * @timeout_us: Timeout in us, 0 means never timeout
> + *
> + * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
> + * case, the last read value at @reg is stored in @val.
> + *
> + * When available, you'll probably want to use one of the specialized
> + * macros defined below rather than this macro directly.
> + *
> + * We do not have timing functions in the PBL, so ignore the timeout value and
> + * loop infinitely here.
> + *
> + * Based on readx_poll_timeout from <linux/iopoll.h>
> + */
> +#define sdhci_readx_poll_timeout(bits, sdhci, reg, val, cond, timeout_us) \
> +({ \
> + uint64_t start; \
> + if (!IN_PBL && timeout_us) \
> + start = get_time_ns(); \
> + for (;;) { \
> + (val) = sdhci_read##bits(sdhci, reg); \
> + if (cond) \
> + break; \
> + if (!IN_PBL && timeout_us && \
> + is_timeout(start, ((timeout_us) * USECOND))) { \
> + (val) = sdhci_read##bits(sdhci, reg); \
> + break; \
> + } \
> + } \
> + (cond) ? 0 : -ETIMEDOUT; \
> +})
Is this really an improvement? How many variants of these helpers will we get?
Sascha
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