Update and bugfix the patch adding sysfs GPIO support:
* Bugfix: the test initializing the IS_OUT flag for output-only
GPIOs had the sense inverted.
* Update: when gpio_chip.dev is provided, list it in the debugfs
dump. Device nodes are unique; the "label" isn't.
The bug of course caused output-only GPIOs to misbehave, but it also
made just-exported (or generally: only-requested) GPIOs always appear
to be outputs in sysfs and debugfs. That's wrong more often than it's
right, although it gets corrected when the direction is assigned.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/gpio/gpiolib.c | 28 +++++++++++++++++++++++-----
1 files changed, 23 insertions(+), 5 deletions(-)
--- a/drivers/gpio/gpiolib.c 2008-06-17 23:15:17.000000000 -0700
+++ b/drivers/gpio/gpiolib.c 2008-06-18 09:48:32.000000000 -0700
@@ -685,7 +685,14 @@ int gpiochip_add(struct gpio_chip *chip)
if (status == 0) {
for (id = base; id < base + chip->ngpio; id++) {
gpio_desc[id].chip = chip;
- gpio_desc[id].flags = chip->direction_input
+
+ /* REVISIT: most hardware initializes GPIOs as
+ * inputs (often with pullups enabled) so power
+ * usage is minimized. Linux code should set the
+ * gpio direction first thing; but until it does,
+ * we may expose the wrong direction in sysfs.
+ */
+ gpio_desc[id].flags = !chip->direction_input
? (1 << FLAG_IS_OUT)
: 0;
}
@@ -1108,17 +1115,28 @@ static int gpiolib_show(struct seq_file
/* REVISIT this isn't locked against gpio_chip removal ... */
for (gpio = 0; gpio_is_valid(gpio); gpio++) {
+ struct device *dev;
+
if (chip == gpio_desc[gpio].chip)
continue;
chip = gpio_desc[gpio].chip;
if (!chip)
continue;
- seq_printf(s, "%sGPIOs %d-%d, %s%s:\n",
+ seq_printf(s, "%sGPIOs %d-%d",
started ? "\n" : "",
- chip->base, chip->base + chip->ngpio - 1,
- chip->label ? : "generic",
- chip->can_sleep ? ", can sleep" : "");
+ chip->base, chip->base + chip->ngpio - 1);
+ dev = chip->dev;
+ if (dev)
+ seq_printf(s, ", %s/%s",
+ dev->bus ? dev->bus->name : "no-bus",
+ dev->bus_id);
+ if (chip->label)
+ seq_printf(s, ", %s", chip->label);
+ if (chip->can_sleep)
+ seq_printf(s, ", can sleep");
+ seq_printf(s, ":\n");
+
started = 1;
if (chip->dbg_show)
chip->dbg_show(s, chip);
--
