From 1e77fc82110ac36febf46c1e2782f504f7d23099 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 9 Jan 2018 19:08:21 +0100 Subject: gpio: Add missing open drain/source handling to gpiod_set_value_cansleep() 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 [removed underscore syntax, added kerneldoc] Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 35 +++++++++++++++++++++++------------ 1 file changed, 23 insertions(+), 12 deletions(-) (limited to 'drivers') 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 @@ -2892,6 +2892,27 @@ 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 @@ -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); -- cgit v1.2.3-59-g8ed1b