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authorDmitry Torokhov <dtor@chromium.org>2016-03-24 10:50:25 -0700
committerLinus Walleij <linus.walleij@linaro.org>2016-04-08 10:10:08 +0200
commit25487533ff311014b0cc39ed7fd721c114e1b11f (patch)
tree47f0df2d5a8311fa1011ccb4e9fbff9b6beeef46
parent9735a22799b9214d17d3c231fe377fc852f042e9 (diff)
downloadlinux-25487533ff311014b0cc39ed7fd721c114e1b11f.tar.bz2
gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*
When firmware does not use _DSD properties that allow properly name GPIO resources, the kernel falls back on parsing _CRS resources, and will return entries described as GpioInt() as general purpose GPIOs even though they are meant to be used simply as interrupt sources for the device: Device (ETSA) { Name (_HID, "ELAN0001") ... Method(_CRS, 0x0, NotSerialized) { Name(BUF0,ResourceTemplate () { I2CSerialBus( 0x10, /* SlaveAddress */ ControllerInitiated, /* SlaveMode */ 400000, /* ConnectionSpeed */ AddressingMode7Bit, /* AddressingMode */ "\\_SB.I2C1", /* ResourceSource */ ) GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,, "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX } } ) Return (BUF0) } ... } This gives troubles with drivers such as Elan Touchscreen driver (elants_i2c) that uses devm_gpiod_get to look up "reset" GPIO line and decide whether the driver is responsible for powering up and resetting the device, or firmware is. In the above case the lookup succeeds, we map GPIO as output and later fail to request client->irq interrupt that is mapped to the same GPIO. Let's ignore resources described as GpioInt() while parsing _CRS when requesting output GPIOs (but allow them when requesting GPIOD_ASIS or GPIOD_IN as some drivers, such as i2c-hid, do request GPIO as input and then map it to interrupt with gpiod_to_irq). Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpiolib.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 72065532c1c7..4a0e66b2b357 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2231,9 +2231,11 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
return desc;
}
-static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
+static struct gpio_desc *acpi_find_gpio(struct device *dev,
+ const char *con_id,
unsigned int idx,
- enum gpio_lookup_flags *flags)
+ enum gpiod_flags flags,
+ enum gpio_lookup_flags *lookupflags)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
struct acpi_gpio_info info;
@@ -2264,10 +2266,16 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
if (IS_ERR(desc))
return desc;
+
+ if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
+ info.gpioint) {
+ dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
+ return ERR_PTR(-ENOENT);
+ }
}
if (info.polarity == GPIO_ACTIVE_LOW)
- *flags |= GPIO_ACTIVE_LOW;
+ *lookupflags |= GPIO_ACTIVE_LOW;
return desc;
}
@@ -2530,7 +2538,7 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
desc = of_find_gpio(dev, con_id, idx, &lookupflags);
} else if (ACPI_COMPANION(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
- desc = acpi_find_gpio(dev, con_id, idx, &lookupflags);
+ desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
}
}