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>
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 547eb85..4e82f64 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1126,9 +1126,12 @@
struct mmc_spi_host *host = mmc_priv(mmc);
if (host->pdata && host->pdata->get_ro)
- return host->pdata->get_ro(mmc->parent);
- /* board doesn't support read only detection; assume writeable */
- return 0;
+ return !!host->pdata->get_ro(mmc->parent);
+ /*
+ * Board doesn't support read only detection; let the mmc core
+ * decide what to do.
+ */
+ return -ENOSYS;
}
static int mmc_spi_get_cd(struct mmc_host *mmc)
