Hi,
I have to get back to this one. The fall-out that made me implement the
patch below in the first place was fixed with the following patch:
e41f76830d (ARM: pxa: dts: add gpio-ranges to gpio controller)
... but now another issue came up.
To recap, the pxa3xx driver uses the pinctrl-single driver since a while
which does not implement a .gpio_set_direction() callback. The pinmux
core will simply return 0 in this case, and the pxa3xx gpio driver hence
thinks the pinctrl driver did its job and returns as well.
This effectively makes pxa_gpio_direction_{input,output} no-ops.
Interestingly, I only noticed that when I tried to use the w1-gpio
driver which makes use of gpiolib's open-drain emulation. All other
use-cases work just fine.
So the question is how this is supposed to work. I see two options:
1) Apply the patch below, so we don't use use the pinctrl driver on PXA3xx.
2) Change pinmux_gpio_direction() and make it return -ENOSYS or
something in case there is no .gpio_set_direction() implementation. I'm
not sure whether that's a good idea though, and what the side-effects
would be.
Any other ideas?
Thanks,
Daniel
On Friday, May 18, 2018 11:34 PM, Daniel Mack wrote:
Commit a770d946371ec7 ("gpio: pxa: add pin control gpio direction and
request") changed the driver to always call out to the pinctrl generic
functions when a GPIO is requested or its direction is configured.
This is fine as long as the platform facilitates a pinctrl driver or
CONFIG_PINCTRL is not set.
On PXA3xx however, we are now using CONFIG_PINCTRL_SINGLE which is not
linked to the gpio subsystem.
To fix this, introduce a small helper function that tells us whether the
platform may expect a pinctrl driver to be present.
Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
Fixes: a770d946371ec7
Cc: Robert Jarzmik <robert.jarzmik@xxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/gpio/gpio-pxa.c | 35 +++++++++++++++++++++++++++--------
1 file changed, 27 insertions(+), 8 deletions(-)
diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index f480fb896963..e217ebccb0c0 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -241,6 +241,17 @@ int pxa_irq_to_gpio(int irq)
return irq_gpio0;
}
+static bool pxa_gpio_has_pinctrl(void)
+{
+ switch (gpio_type) {
+ case PXA3XX_GPIO:
+ return false;
+
+ default:
+ return true;
+ }
+}
+
static int pxa_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct pxa_gpio_chip *pchip = chip_to_pxachip(chip);
@@ -255,9 +266,11 @@ static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
unsigned long flags;
int ret;
- ret = pinctrl_gpio_direction_input(chip->base + offset);
- if (!ret)
- return 0;
+ if (pxa_gpio_has_pinctrl()) {
+ ret = pinctrl_gpio_direction_input(chip->base + offset);
+ if (!ret)
+ return 0;
+ }
spin_lock_irqsave(&gpio_lock, flags);
@@ -282,9 +295,11 @@ static int pxa_gpio_direction_output(struct gpio_chip *chip,
writel_relaxed(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
- ret = pinctrl_gpio_direction_output(chip->base + offset);
- if (ret)
- return ret;
+ if (pxa_gpio_has_pinctrl()) {
+ ret = pinctrl_gpio_direction_output(chip->base + offset);
+ if (ret)
+ return ret;
+ }
spin_lock_irqsave(&gpio_lock, flags);
@@ -348,8 +363,12 @@ static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio,
pchip->chip.set = pxa_gpio_set;
pchip->chip.to_irq = pxa_gpio_to_irq;
pchip->chip.ngpio = ngpio;
- pchip->chip.request = gpiochip_generic_request;
- pchip->chip.free = gpiochip_generic_free;
+
+ if (pxa_gpio_has_pinctrl()) {
+ pchip->chip.request = gpiochip_generic_request;
+ pchip->chip.free = gpiochip_generic_free;
+ }
+
#ifdef CONFIG_OF_GPIO
pchip->chip.of_node = np;
pchip->chip.of_xlate = pxa_gpio_of_xlate;
--
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