[PATCH 3/3] mmc: change .get_ro() callback semantics
Anton Vorontsov
avorontsov at ru.mvista.com
Sat May 24 01:43:47 EST 2008
get_ro() callback must return values >= 0 for its logical state, 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 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 at ru.mvista.com>
---
drivers/mmc/core/sd.c | 4 ++--
drivers/mmc/host/at91_mci.c | 2 +-
drivers/mmc/host/imxmmc.c | 9 ++++++---
drivers/mmc/host/mmc_spi.c | 9 ++++++---
drivers/mmc/host/pxamci.c | 9 ++++++---
include/linux/mmc/host.h | 3 +++
6 files changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 7ef3b15..b122eb9 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -494,13 +494,13 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
* Check if read-only switch is active.
*/
if (!oldcard) {
- if (!host->ops->get_ro) {
+ if (!host->ops->get_ro || host->ops->get_ro(host) < 0) {
printk(KERN_WARNING "%s: host does not "
"support reading read-only "
"switch. assuming write-enable.\n",
mmc_hostname(host));
} else {
- if (host->ops->get_ro(host))
+ if (host->ops->get_ro(host) > 0)
mmc_card_set_readonly(card);
}
}
diff --git a/drivers/mmc/host/at91_mci.c b/drivers/mmc/host/at91_mci.c
index 8979ad3..140c2b8 100644
--- a/drivers/mmc/host/at91_mci.c
+++ b/drivers/mmc/host/at91_mci.c
@@ -797,7 +797,7 @@ static int at91_mci_get_ro(struct mmc_host *mmc)
struct at91mci_host *host = mmc_priv(mmc);
if (host->board->wp_pin) {
- read_only = gpio_get_value(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") );
}
diff --git a/drivers/mmc/host/imxmmc.c b/drivers/mmc/host/imxmmc.c
index 95f33e8..5167679 100644
--- a/drivers/mmc/host/imxmmc.c
+++ b/drivers/mmc/host/imxmmc.c
@@ -889,9 +889,12 @@ static int imxmci_get_ro(struct mmc_host *mmc)
struct imxmci_host *host = mmc_priv(mmc);
if (host->pdata && host->pdata->get_ro)
- return host->pdata->get_ro(mmc_dev(mmc));
- /* Host doesn't support read only detection so assume writeable */
- return 0;
+ return !!host->pdata->get_ro(mmc_dev(mmc));
+ /*
+ * Board doesn't support read only detection; let the mmc core
+ * decide what to do.
+ */
+ return -ENOSYS;
}
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 724870c..85d9853 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1126,9 +1126,12 @@ static int mmc_spi_get_ro(struct mmc_host *mmc)
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)
diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c
index 65210fc..b6056bd 100644
--- a/drivers/mmc/host/pxamci.c
+++ b/drivers/mmc/host/pxamci.c
@@ -361,9 +361,12 @@ static int pxamci_get_ro(struct mmc_host *mmc)
struct pxamci_host *host = mmc_priv(mmc);
if (host->pdata && host->pdata->get_ro)
- return host->pdata->get_ro(mmc_dev(mmc));
- /* Host doesn't support read only detection so assume writeable */
- return 0;
+ return !!host->pdata->get_ro(mmc_dev(mmc));
+ /*
+ * Board doesn't support read only detection; let the mmc core
+ * decide what to do.
+ */
+ return -ENOSYS;
}
static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f2e9885..ef3b773 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -55,6 +55,9 @@ struct mmc_host_ops {
* Avoid calling these three functions too often or in a "fast path",
* since underlaying controller might implement them in an expensive
* and/or slow way.
+ *
+ * .get_ro and .get_cd should return >= 0 for their logical values,
+ * or negative errno value in case of error.
*/
void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
int (*get_ro)(struct mmc_host *host);
--
1.5.5.1
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