From 08f80bb5196517a0dfe50dc7c10f234c0ff2f0e8 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 17 Jun 2008 18:17:39 +0400 Subject: mmc: change .get_ro() callback semantics Now get_ro() callback must return 0/1 values for its logical states, and negative errno values in case of error. If particular host instance doesn't support RO/WP switch, it should return -ENOSYS. This patch changes some hosts in two ways: 1. Now functions should be smart to not return negative values in "RO asserted" case (particularly gpio_ calls could return negative values for the outermost GPIOs). Also, board code usually passes get_ro() callbacks that directly return gpioreg & bit result, so at91_mci, imxmmc, pxamci and mmc_spi's get_ro() handlers need take special care when returning platform's values to the mmc core. 2. In case of host instance didn't implement get_ro() callback, it should really return -ENOSYS and let the mmc core decide what to do about it (mmc core thinks the same way as the hosts, so it isn't functional change). Signed-off-by: Anton Vorontsov Signed-off-by: Pierre Ossman --- include/linux/mmc/host.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/mmc') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 6188e19d233..753b7231b88 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -58,6 +58,18 @@ struct mmc_host_ops { * * Also note that these functions might sleep, so don't call them * in the atomic contexts! + * + * Return values for the get_ro callback should be: + * 0 for a read/write card + * 1 for a read-only card + * -ENOSYS when not supported (equal to NULL callback) + * or a negative errno value when something bad happened + * + * Return values for the get_ro callback should be: + * 0 for a absent card + * 1 for a present card + * -ENOSYS when not supported (equal to NULL callback) + * or a negative errno value when something bad happened */ void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios); int (*get_ro)(struct mmc_host *host); -- cgit v1.2.3