[PATCH 3/3] mmc: change .get_ro() callback semantics
From: Anton Vorontsov
Date: Tue Jun 17 2008 - 10:17:54 EST
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@xxxxxxxxxxxxx>
---
drivers/mmc/core/sd.c | 4 ++--
drivers/mmc/host/at91_mci.c | 18 +++++++-----------
drivers/mmc/host/imxmmc.c | 9 ++++++---
drivers/mmc/host/mmc_spi.c | 9 ++++++---
drivers/mmc/host/pxamci.c | 9 ++++++---
drivers/mmc/host/wbsd.c | 2 +-
include/linux/mmc/host.h | 12 ++++++++++++
7 files changed, 40 insertions(+), 23 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..b9d4ed6 100644
--- a/drivers/mmc/host/at91_mci.c
+++ b/drivers/mmc/host/at91_mci.c
@@ -793,19 +793,15 @@ static irqreturn_t at91_mmc_det_irq(int irq, void *_host)
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 = {
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 547eb85..4e82f64 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/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index be624a0..9283b85 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -939,7 +939,7 @@ static int wbsd_get_ro(struct mmc_host *mmc)
spin_unlock_bh(&host->lock);
- return csr & WBSD_WRPT;
+ return !!(csr & WBSD_WRPT);
}
static const struct mmc_host_ops wbsd_ops = {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 6188e19..753b723 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);
--
1.5.5.4
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