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/at91_mci.c b/drivers/mmc/host/at91_mci.c
index 8979ad3..b9d4ed6 100644
--- a/drivers/mmc/host/at91_mci.c
+++ b/drivers/mmc/host/at91_mci.c
@@ -793,19 +793,15 @@
static int at91_mci_get_ro(struct mmc_host *mmc)
{
- int read_only = 0;
struct at91mci_host *host = mmc_priv(mmc);
- if (host->board->wp_pin) {
- read_only = gpio_get_value(host->board->wp_pin);
- printk(KERN_WARNING "%s: card is %s\n", mmc_hostname(mmc),
- (read_only ? "read-only" : "read-write") );
- }
- else {
- printk(KERN_WARNING "%s: host does not support reading read-only "
- "switch. Assuming write-enable.\n", mmc_hostname(mmc));
- }
- return read_only;
+ if (host->board->wp_pin)
+ return !!gpio_get_value(host->board->wp_pin);
+ /*
+ * Board doesn't support read only detection; let the mmc core
+ * decide what to do.
+ */
+ return -ENOSYS;
}
static const struct mmc_host_ops at91_mci_ops = {