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authorAnton Vorontsov <avorontsov@ru.mvista.com>2008-06-17 18:17:39 +0400
committerPierre Ossman <drzeus@drzeus.cx>2008-07-15 14:14:41 +0200
commit08f80bb5196517a0dfe50dc7c10f234c0ff2f0e8 (patch)
treeaee5e1808521eb3c00ff37d50a2e8957bebbd34b /include/linux
parent619ef4b42128709de4d89d209b2c874f560deecd (diff)
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 <avorontsov@ru.mvista.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/mmc/host.h12
1 files changed, 12 insertions, 0 deletions
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);