| Message ID | 1356102464-22234-1-git-send-email-javier.martinez@collabora.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Dec 21, 2012 at 12:07 PM, Javier Martinez Canillas <javier.martinez@collabora.co.uk> wrote: > commit a99d76f leds: leds-gpio: use gpio_request_one > > changed the leds-gpio driver to use gpio_request_one() instead > of gpio_request() + gpio_direction_output() > > Unfortunately, it also made a semantic change that breaks the > leds-gpio driver. > > The gpio_request_one() flags parameter was set to: > > GPIOF_DIR_OUT | (led_dat->active_low ^ state) > > Since GPIOF_DIR_OUT is 0, the final flags value will just be the > XOR'ed value of led_dat->active_low and state. > > This value were used to distinguish between HIGH/LOW output initial > level and call gpio_direction_output() accordingly. > > With this new semantic gpio_request_one() will take the flags value > of 1 as a configuration of input direction (GPIOF_DIR_IN) and will > call gpio_direction_input() instead of gpio_direction_output(). > > int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) > { > .. > if (flags & GPIOF_DIR_IN) > err = gpio_direction_input(gpio); > else > err = gpio_direction_output(gpio, > (flags & GPIOF_INIT_HIGH) ? 1 : 0); > .. > } > > The right semantic is to evaluate led_dat->active_low ^ state and > set the output initial level explicitly. > > Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> > --- > > This makes LEDs to work again on my IGEPv2 board (TI OMAP3 based SoC). > > I sent this patch before but then realized that I only cc'ed to linux-leds. > So, I'm resending the patch cc'ing linux-omap,linux-arm-kernel and LKML to > reach a broader audience and have more people review/test the patch. > > Sorry for the noise if someone got it twice. > > drivers/leds/leds-gpio.c | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c > index 1885a26..a0d931b 100644 > --- a/drivers/leds/leds-gpio.c > +++ b/drivers/leds/leds-gpio.c > @@ -127,8 +127,9 @@ static int create_gpio_led(const struct gpio_led *template, > led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; > > ret = devm_gpio_request_one(parent, template->gpio, > - GPIOF_DIR_OUT | (led_dat->active_low ^ state), > - template->name); > + (led_dat->active_low ^ state) ? > + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, > + template->name); > if (ret < 0) > return ret; > > -- > 1.7.7.6 > Without this patch my IGEP v2 LEDs were dead, and this patch brings them back. Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Thanks, Ezequiel
On 12/21/2012 06:06 PM, Ezequiel Garcia wrote: > On Fri, Dec 21, 2012 at 12:07 PM, Javier Martinez Canillas > <javier.martinez@collabora.co.uk> wrote: >> commit a99d76f leds: leds-gpio: use gpio_request_one >> >> changed the leds-gpio driver to use gpio_request_one() instead >> of gpio_request() + gpio_direction_output() >> >> Unfortunately, it also made a semantic change that breaks the >> leds-gpio driver. >> >> The gpio_request_one() flags parameter was set to: >> >> GPIOF_DIR_OUT | (led_dat->active_low ^ state) >> >> Since GPIOF_DIR_OUT is 0, the final flags value will just be the >> XOR'ed value of led_dat->active_low and state. >> >> This value were used to distinguish between HIGH/LOW output initial >> level and call gpio_direction_output() accordingly. >> >> With this new semantic gpio_request_one() will take the flags value >> of 1 as a configuration of input direction (GPIOF_DIR_IN) and will >> call gpio_direction_input() instead of gpio_direction_output(). >> >> int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) >> { >> .. >> if (flags & GPIOF_DIR_IN) >> err = gpio_direction_input(gpio); >> else >> err = gpio_direction_output(gpio, >> (flags & GPIOF_INIT_HIGH) ? 1 : 0); >> .. >> } >> >> The right semantic is to evaluate led_dat->active_low ^ state and >> set the output initial level explicitly. >> >> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> >> --- >> >> This makes LEDs to work again on my IGEPv2 board (TI OMAP3 based SoC). >> >> I sent this patch before but then realized that I only cc'ed to linux-leds. >> So, I'm resending the patch cc'ing linux-omap,linux-arm-kernel and LKML to >> reach a broader audience and have more people review/test the patch. >> >> Sorry for the noise if someone got it twice. >> >> drivers/leds/leds-gpio.c | 5 +++-- >> 1 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c >> index 1885a26..a0d931b 100644 >> --- a/drivers/leds/leds-gpio.c >> +++ b/drivers/leds/leds-gpio.c >> @@ -127,8 +127,9 @@ static int create_gpio_led(const struct gpio_led *template, >> led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; >> >> ret = devm_gpio_request_one(parent, template->gpio, >> - GPIOF_DIR_OUT | (led_dat->active_low ^ state), >> - template->name); >> + (led_dat->active_low ^ state) ? >> + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, >> + template->name); >> if (ret < 0) >> return ret; >> >> -- >> 1.7.7.6 >> > > Without this patch my IGEP v2 LEDs were dead, > and this patch brings them back. > > Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> > > Thanks, > > Ezequiel > Hello, Any news on this? GPIO LEDs support is still not working on latest mainline kernel and other people report that this patch solves the issue for them. Thanks a lot and best regards, Javier
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index 1885a26..a0d931b 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -127,8 +127,9 @@ static int create_gpio_led(const struct gpio_led *template, led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; ret = devm_gpio_request_one(parent, template->gpio, - GPIOF_DIR_OUT | (led_dat->active_low ^ state), - template->name); + (led_dat->active_low ^ state) ? + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, + template->name); if (ret < 0) return ret;
commit a99d76f leds: leds-gpio: use gpio_request_one changed the leds-gpio driver to use gpio_request_one() instead of gpio_request() + gpio_direction_output() Unfortunately, it also made a semantic change that breaks the leds-gpio driver. The gpio_request_one() flags parameter was set to: GPIOF_DIR_OUT | (led_dat->active_low ^ state) Since GPIOF_DIR_OUT is 0, the final flags value will just be the XOR'ed value of led_dat->active_low and state. This value were used to distinguish between HIGH/LOW output initial level and call gpio_direction_output() accordingly. With this new semantic gpio_request_one() will take the flags value of 1 as a configuration of input direction (GPIOF_DIR_IN) and will call gpio_direction_input() instead of gpio_direction_output(). int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) { .. if (flags & GPIOF_DIR_IN) err = gpio_direction_input(gpio); else err = gpio_direction_output(gpio, (flags & GPIOF_INIT_HIGH) ? 1 : 0); .. } The right semantic is to evaluate led_dat->active_low ^ state and set the output initial level explicitly. Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> --- This makes LEDs to work again on my IGEPv2 board (TI OMAP3 based SoC). I sent this patch before but then realized that I only cc'ed to linux-leds. So, I'm resending the patch cc'ing linux-omap,linux-arm-kernel and LKML to reach a broader audience and have more people review/test the patch. Sorry for the noise if someone got it twice. drivers/leds/leds-gpio.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)