[v3,1/4] serial: mctrl_gpio: Avoid probe failures in case of missing gpiolib

Commit Message

Frieder Schrempf Aug. 2, 2019, 10:04 a.m. UTC

From: Frieder Schrempf <[e-mail]>

If CONFIG_GPIOLIB is not enabled, mctrl_gpio_init() and
mctrl_gpio_init_noauto() will currently return an error pointer with
-ENOSYS. As the mctrl GPIOs are usually optional, drivers need to
check for this condition to allow continue probing.

To avoid the need for this check in each driver, we return NULL
instead, as all the mctrl_gpio_*() functions are skipped anyway.
We also adapt mctrl_gpio_to_gpiod() to be in line with this change.

Reviewed-by: Fabio Estevam <[e-mail]>
Signed-off-by: Frieder Schrempf <[e-mail]>
---
Changes in v3
=============
* Move the changes in mctrl_gpio_to_gpiod() to a separate patch
* Reorder tags

Changes in v2
=============
* Move the sh_sci changes to a separate patch
* Add Fabio's R-b tag
---
 drivers/tty/serial/serial_mctrl_gpio.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Uwe Kleine-König Aug. 2, 2019, 12:08 p.m. UTC | #1

On Fri, Aug 02, 2019 at 10:04:09AM +0000, Schrempf Frieder wrote:
> From: Frieder Schrempf <[e-mail]>
> 
> If CONFIG_GPIOLIB is not enabled, mctrl_gpio_init() and
> mctrl_gpio_init_noauto() will currently return an error pointer with
> -ENOSYS. As the mctrl GPIOs are usually optional, drivers need to
> check for this condition to allow continue probing.
> 
> To avoid the need for this check in each driver, we return NULL
> instead, as all the mctrl_gpio_*() functions are skipped anyway.
> We also adapt mctrl_gpio_to_gpiod() to be in line with this change.
> 
> Reviewed-by: Fabio Estevam <[e-mail]>
> Signed-off-by: Frieder Schrempf <[e-mail]>

Reviewed-by: Uwe Kleine-König <[e-mail]>

Thanks
Uwe

Geert Uytterhoeven Aug. 6, 2019, 8:09 a.m. UTC | #2

On Fri, Aug 2, 2019 at 12:04 PM Schrempf Frieder
<[e-mail]> wrote:
> From: Frieder Schrempf <[e-mail]>
>
> If CONFIG_GPIOLIB is not enabled, mctrl_gpio_init() and
> mctrl_gpio_init_noauto() will currently return an error pointer with
> -ENOSYS. As the mctrl GPIOs are usually optional, drivers need to
> check for this condition to allow continue probing.
>
> To avoid the need for this check in each driver, we return NULL
> instead, as all the mctrl_gpio_*() functions are skipped anyway.
> We also adapt mctrl_gpio_to_gpiod() to be in line with this change.
>
> Reviewed-by: Fabio Estevam <[e-mail]>
> Signed-off-by: Frieder Schrempf <[e-mail]>

Reviewed-by: Geert Uytterhoeven <[e-mail]>

Gr{oetje,eeting}s,

                        Geert

Patch

diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
index b7d3cca48ede..1b2ff503b2c2 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.h
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -114,19 +114,19 @@  static inline
 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 				      enum mctrl_gpio_idx gidx)
 {
-	return ERR_PTR(-ENOSYS);
+	return NULL;
 }
 
 static inline
 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 {
-	return ERR_PTR(-ENOSYS);
+	return NULL;
 }
 
 static inline
 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 {
-	return ERR_PTR(-ENOSYS);
+	return NULL;
 }
 
 static inline