diff mbox series

[2/3,v3] gpio: Handle counting of Freescale chipselects

Message ID 20191128083718.39177-2-linus.walleij@linaro.org (mailing list archive)
State Accepted
Commit 71b8f600b034c7f5780f6fb311dabfe331c64feb
Headers show
Series [1/3,v3] spi: fsl: Fix GPIO descriptor support | expand

Commit Message

Linus Walleij Nov. 28, 2019, 8:37 a.m. UTC
We have a special quirk to handle the Freescale
nonstandard SPI chipselect GPIOs in the gpiolib-of.c
file, but it currently only handles the case where
the GPIOs are actually requested (gpiod_*get()).

We also need to handle that the SPI core attempts
to count the GPIOs before use, and that needs a
similar quirk in the OF part of the library.

Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Fixed the bug (I hope) as I was counting the number
  of gpios by checking for "gpios-gpios" and "gpios-gpio"
  rather than "gpios" (ehm...)
ChangeLog v1->v2:
- Hardcode the quirk to look for "gpios" as this is all
  we support and else the call would just recurse back
  and fail again.
- Provide a proper NULL check so we don't upset strcmp().

Mark: I change my mind, better to keep the patches
together, once Christophe has it working with my
patch stack let's just merge all of it.
---
 drivers/gpio/gpiolib-of.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

Comments

Christophe Leroy Nov. 28, 2019, 12:14 p.m. UTC | #1
Le 28/11/2019 à 09:37, Linus Walleij a écrit :
> We have a special quirk to handle the Freescale
> nonstandard SPI chipselect GPIOs in the gpiolib-of.c
> file, but it currently only handles the case where
> the GPIOs are actually requested (gpiod_*get()).
> 
> We also need to handle that the SPI core attempts
> to count the GPIOs before use, and that needs a
> similar quirk in the OF part of the library.
> 
> Cc: Christophe Leroy <christophe.leroy@c-s.fr>
> Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Fixes: 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors")
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Tested-by: Christophe Leroy <christophe.leroy@c-s.fr>

> ---
> ChangeLog v2->v3:
> - Fixed the bug (I hope) as I was counting the number
>    of gpios by checking for "gpios-gpios" and "gpios-gpio"
>    rather than "gpios" (ehm...)
> ChangeLog v1->v2:
> - Hardcode the quirk to look for "gpios" as this is all
>    we support and else the call would just recurse back
>    and fail again.
> - Provide a proper NULL check so we don't upset strcmp().
> 
> Mark: I change my mind, better to keep the patches
> together, once Christophe has it working with my
> patch stack let's just merge all of it.
> ---
>   drivers/gpio/gpiolib-of.c | 27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index 80ea49f570f4..43ffec3a6fbb 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -23,6 +23,29 @@
>   #include "gpiolib.h"
>   #include "gpiolib-of.h"
>   
> +/**
> + * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
> + * Some elder GPIO controllers need special quirks. Currently we handle
> + * the Freescale GPIO controller with bindings that doesn't use the
> + * established "cs-gpios" for chip selects but instead rely on
> + * "gpios" for the chip select lines. If we detect this, we redirect
> + * the counting of "cs-gpios" to count "gpios" transparent to the
> + * driver.
> + */
> +int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
> +{
> +	struct device_node *np = dev->of_node;
> +
> +	if (!IS_ENABLED(CONFIG_SPI_MASTER))
> +		return 0;
> +	if (!con_id || strcmp(con_id, "cs"))
> +		return 0;
> +	if (!of_device_is_compatible(np, "fsl,spi") &&
> +	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
> +		return 0;
> +	return of_gpio_named_count(np, "gpios");
> +}
> +
>   /*
>    * This is used by external users of of_gpio_count() from <linux/of_gpio.h>
>    *
> @@ -35,6 +58,10 @@ int of_gpio_get_count(struct device *dev, const char *con_id)
>   	char propname[32];
>   	unsigned int i;
>   
> +	ret = of_gpio_spi_cs_get_count(dev, con_id);
> +	if (ret > 0)
> +		return ret;
> +
>   	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
>   		if (con_id)
>   			snprintf(propname, sizeof(propname), "%s-%s",
>
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 80ea49f570f4..43ffec3a6fbb 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -23,6 +23,29 @@ 
 #include "gpiolib.h"
 #include "gpiolib-of.h"
 
+/**
+ * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
+ * Some elder GPIO controllers need special quirks. Currently we handle
+ * the Freescale GPIO controller with bindings that doesn't use the
+ * established "cs-gpios" for chip selects but instead rely on
+ * "gpios" for the chip select lines. If we detect this, we redirect
+ * the counting of "cs-gpios" to count "gpios" transparent to the
+ * driver.
+ */
+int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
+{
+	struct device_node *np = dev->of_node;
+
+	if (!IS_ENABLED(CONFIG_SPI_MASTER))
+		return 0;
+	if (!con_id || strcmp(con_id, "cs"))
+		return 0;
+	if (!of_device_is_compatible(np, "fsl,spi") &&
+	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
+		return 0;
+	return of_gpio_named_count(np, "gpios");
+}
+
 /*
  * This is used by external users of of_gpio_count() from <linux/of_gpio.h>
  *
@@ -35,6 +58,10 @@  int of_gpio_get_count(struct device *dev, const char *con_id)
 	char propname[32];
 	unsigned int i;
 
+	ret = of_gpio_spi_cs_get_count(dev, con_id);
+	if (ret > 0)
+		return ret;
+
 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 		if (con_id)
 			snprintf(propname, sizeof(propname), "%s-%s",