Messages in this thread Patch in this message | | | From | David Brownell <> | Subject | [patch 2.6.26-rc6-mm] gpio: updates to sysfs support | Date | Wed, 18 Jun 2008 12:19:55 -0700 |
| |
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);
| |