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authorGeert Uytterhoeven <geert+renesas@glider.be>2018-01-09 19:08:21 +0100
committerLinus Walleij <linus.walleij@linaro.org>2018-01-10 14:17:17 +0100
commit1e77fc82110ac36febf46c1e2782f504f7d23099 (patch)
treef722590f4dfaabcf0ba0ebf3bce28e1259371ab0
parentb2cd1df66037e7c4697c7e40496bf7e4a5e16a2d (diff)
gpio: Add missing open drain/source handling to gpiod_set_value_cansleep()gpio-v4.15-4
Since commit f11a04464ae57e8d ("i2c: gpio: Enable working over slow can_sleep GPIOs"), probing the i2c RTC connected to an i2c-gpio bus on r8a7740/armadillo fails with: rtc-s35390a 0-0030: error resetting chip rtc-s35390a: probe of 0-0030 failed with error -5 More debug code reveals: i2c i2c-0: master_xfer[0] R, addr=0x30, len=1 i2c i2c-0: NAK from device addr 0x30 msg #0 s35390a_get_reg: ret = -6 Commit 02e479808b5d62f8 ("gpio: Alter semantics of *raw* operations to actually be raw") moved open drain/source handling from gpiod_set_raw_value_commit() to gpiod_set_value(), but forgot to take into account that gpiod_set_value_cansleep() also needs this handling. The i2c protocol mandates that i2c signals are open drain, hence i2c communication fails. Fix this by adding the missing handling to gpiod_set_value_cansleep(), using a new common helper gpiod_set_value_nocheck(). Fixes: 02e479808b5d62f8 ("gpio: Alter semantics of *raw* operations to actually be raw") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> [removed underscore syntax, added kerneldoc] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpiolib.c35
1 files changed, 23 insertions, 12 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 44332b793718..14532d9576e4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2893,6 +2893,27 @@ void gpiod_set_raw_value(struct gpio_desc *desc, int value)
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
+ * gpiod_set_value_nocheck() - set a GPIO line value without checking
+ * @desc: the descriptor to set the value on
+ * @value: value to set
+ *
+ * This sets the value of a GPIO line backing a descriptor, applying
+ * different semantic quirks like active low and open drain/source
+ * handling.
+ */
+static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
+{
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+ gpio_set_open_drain_value_commit(desc, value);
+ else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+ gpio_set_open_source_value_commit(desc, value);
+ else
+ gpiod_set_raw_value_commit(desc, value);
+}
+
+/**
* gpiod_set_value() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
@@ -2906,16 +2927,8 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
void gpiod_set_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
- /* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
- if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
- value = !value;
- if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
- gpio_set_open_drain_value_commit(desc, value);
- else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
- gpio_set_open_source_value_commit(desc, value);
- else
- gpiod_set_raw_value_commit(desc, value);
+ gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value);
@@ -3243,9 +3256,7 @@ void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
VALIDATE_DESC_VOID(desc);
- if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
- value = !value;
- gpiod_set_raw_value_commit(desc, value);
+ gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);

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