[PATCH 2/6] of: Return -ENXIO from of_parse_phandle_with_args for too large index and return errors from of_gpio_named_count

From: Andreas Larsson
Date: Thu Dec 27 2012 - 07:11:41 EST


This lets of_gpio_named_count return an errno on errors by being able to
distinguish between reaching the end of the phandle list and getting some other
error from of_parse_phandle_with_args.

Return error from of_spi_register_master when there is an "cs-gpios" list for
which gp_gpio_named_count fails.

Adjust drivers/hwmon/gpio-fan.c to cope with error return.

Signed-off-by: Andreas Larsson <andreas@xxxxxxxxxxx>
---

Uses -ENXIO modelled after uses such as in platform_get_irq, but maybe some
other errno than ENXIO is more appropriate for this case.

drivers/gpio/gpiolib-of.c | 8 +++++---
drivers/hwmon/gpio-fan.c | 2 +-
drivers/of/base.c | 5 ++++-
drivers/spi/spi.c | 11 +++++++----
4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index d542a14..28f24a6 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -107,11 +107,10 @@ EXPORT_SYMBOL(of_get_named_gpio_flags);
*/
unsigned int of_gpio_named_count(struct device_node *np, const char* propname)
{
+ int ret;
unsigned int cnt = 0;

do {
- int ret;
-
ret = of_parse_phandle_with_args(np, propname, "#gpio-cells",
cnt, NULL);
/* A hole in the gpios = <> counts anyway. */
@@ -119,7 +118,10 @@ unsigned int of_gpio_named_count(struct device_node *np, const char* propname)
break;
} while (++cnt);

- return cnt;
+ if (ret == -ENXIO)
+ return cnt;
+ else
+ return ret;
}
EXPORT_SYMBOL(of_gpio_named_count);

diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 4e04c12..9ccd92f 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -477,7 +477,7 @@ static int gpio_fan_get_of_pdata(struct device *dev,
pdata->speed = speed;

/* Alarm GPIO if one exists */
- if (of_gpio_named_count(node, "alarm-gpios")) {
+ if (of_gpio_named_count(node, "alarm-gpios") > 0) {
struct gpio_fan_alarm *alarm;
int val;
enum of_gpio_flags flags;
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 986afd7..1f16629 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1110,7 +1110,10 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
/* Loop exited without finding a valid entry; return an error */
if (node)
of_node_put(node);
- return -EINVAL;
+ if (list == list_end)
+ return -ENXIO; /* Index beyond end of list */
+ else
+ return -EINVAL;
}
EXPORT_SYMBOL(of_parse_phandle_with_args);

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 19ee901..9c2acf1 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1059,7 +1059,7 @@ EXPORT_SYMBOL_GPL(spi_alloc_master);
#ifdef CONFIG_OF
static int of_spi_register_master(struct spi_master *master)
{
- u16 nb;
+ int nb;
int i, *cs;
struct device_node *np = master->dev.of_node;

@@ -1067,10 +1067,13 @@ static int of_spi_register_master(struct spi_master *master)
return 0;

nb = of_gpio_named_count(np, "cs-gpios");
- master->num_chipselect = max(nb, master->num_chipselect);
-
- if (nb < 1)
+ if (nb == 0 || nb == -ENOENT) /* No error if cs-gpios does not exist */
return 0;
+ else if (nb < 0)
+ return nb;
+
+ if (nb > master->num_chipselect)
+ master->num_chipselect = (u16)nb;

cs = devm_kzalloc(&master->dev,
sizeof(int) * master->num_chipselect,
--
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/