pinctrl: st: stop abusing of_get_named_gpio()

[PATCH] pinctrl: st: stop abusing of_get_named_gpio()

Posted by Dmitry Torokhov 1 year, 6 months ago

Pin descriptions for this chip only look like standard GPIO device tree
descriptions, while in fact they contain additional data (in excess of
number of cells specified in description of gpio controllers). They also
refer to only pins/gpios belonging to the driver and not to arbitrary
gpio in the system.

Because we want to stop exporting OF-specific handlers from gpiolib-of,
let's parse the pin reference ourself instead of trying to call
of_get_named_gpio().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

Just compiled, not tested on real hardware.

 drivers/pinctrl/pinctrl-st.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 0fea71fd9a00..cf7f9cbe6044 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -12,7 +12,6 @@
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
-#include <linux/of_gpio.h> /* of_get_named_gpio() */
 #include <linux/of_address.h>
 #include <linux/gpio/driver.h>
 #include <linux/regmap.h>
@@ -1162,6 +1161,31 @@ static void st_parse_syscfgs(struct st_pinctrl *info, int bank,
 	return;
 }
 
+static int st_pctl_dt_calculate_pin(struct st_pinctrl *info,
+				    phandle bank, unsigned int offset)
+{
+	struct device_node *np;
+	struct gpio_chip *chip;
+	int retval = -EINVAL;
+	int i;
+
+	np = of_find_node_by_phandle(bank);
+	if (!np)
+		return -EINVAL;
+
+	for (i = 0; i < info->nbanks; i++) {
+		chip = &info->banks[i].gpio_chip;
+		if (chip->of_node == np) {
+			if (offset < chip->ngpio)
+				retval = chip->base + offset;
+			break;
+		}
+	}
+
+	of_node_put(np);
+	return retval;
+}
+
 /*
  * Each pin is represented in of the below forms.
  * <bank offset mux direction rt_type rt_delay rt_clk>
@@ -1175,6 +1199,8 @@ static int st_pctl_dt_parse_groups(struct device_node *np,
 	struct device *dev = info->dev;
 	struct st_pinconf *conf;
 	struct device_node *pins;
+	phandle bank;
+	unsigned int offset;
 	int i = 0, npins = 0, nr_props, ret = 0;
 
 	pins = of_get_child_by_name(np, "st,pins");
@@ -1214,9 +1240,9 @@ static int st_pctl_dt_parse_groups(struct device_node *np,
 		conf = &grp->pin_conf[i];
 
 		/* bank & offset */
-		be32_to_cpup(list++);
-		be32_to_cpup(list++);
-		conf->pin = of_get_named_gpio(pins, pp->name, 0);
+		bank = be32_to_cpup(list++);
+		offset = be32_to_cpup(list++);
+		conf->pin = st_pctl_dt_calculate_pin(info, bank, offset);
 		conf->name = pp->name;
 		grp->pins[i] = conf->pin;
 		/* mux */
-- 
2.38.0.rc1.362.ged0d419d3c-goog


-- 
Dmitry

Re: [PATCH] pinctrl: st: stop abusing of_get_named_gpio()

Posted by Linus Walleij 1 year, 6 months ago

On Wed, Sep 28, 2022 at 10:20 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:

> Pin descriptions for this chip only look like standard GPIO device tree
> descriptions, while in fact they contain additional data (in excess of
> number of cells specified in description of gpio controllers). They also
> refer to only pins/gpios belonging to the driver and not to arbitrary
> gpio in the system.
>
> Because we want to stop exporting OF-specific handlers from gpiolib-of,
> let's parse the pin reference ourself instead of trying to call
> of_get_named_gpio().
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Excellent work as usual, patch applied.

Yours,
Linus Walleij

Re: [PATCH] pinctrl: st: stop abusing of_get_named_gpio()

Posted by Patrice CHOTARD 1 year, 6 months ago

Hi Dmitry

On 9/28/22 22:20, Dmitry Torokhov wrote:
> Pin descriptions for this chip only look like standard GPIO device tree
> descriptions, while in fact they contain additional data (in excess of
> number of cells specified in description of gpio controllers). They also
> refer to only pins/gpios belonging to the driver and not to arbitrary
> gpio in the system.
> 
> Because we want to stop exporting OF-specific handlers from gpiolib-of,
> let's parse the pin reference ourself instead of trying to call
> of_get_named_gpio().
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
> 
> Just compiled, not tested on real hardware.
> 
>  drivers/pinctrl/pinctrl-st.c | 34 ++++++++++++++++++++++++++++++----
>  1 file changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 0fea71fd9a00..cf7f9cbe6044 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -12,7 +12,6 @@
>  #include <linux/io.h>
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
> -#include <linux/of_gpio.h> /* of_get_named_gpio() */
>  #include <linux/of_address.h>
>  #include <linux/gpio/driver.h>
>  #include <linux/regmap.h>
> @@ -1162,6 +1161,31 @@ static void st_parse_syscfgs(struct st_pinctrl *info, int bank,
>  	return;
>  }
>  
> +static int st_pctl_dt_calculate_pin(struct st_pinctrl *info,
> +				    phandle bank, unsigned int offset)
> +{
> +	struct device_node *np;
> +	struct gpio_chip *chip;
> +	int retval = -EINVAL;
> +	int i;
> +
> +	np = of_find_node_by_phandle(bank);
> +	if (!np)
> +		return -EINVAL;
> +
> +	for (i = 0; i < info->nbanks; i++) {
> +		chip = &info->banks[i].gpio_chip;
> +		if (chip->of_node == np) {
> +			if (offset < chip->ngpio)
> +				retval = chip->base + offset;
> +			break;
> +		}
> +	}
> +
> +	of_node_put(np);
> +	return retval;
> +}
> +
>  /*
>   * Each pin is represented in of the below forms.
>   * <bank offset mux direction rt_type rt_delay rt_clk>
> @@ -1175,6 +1199,8 @@ static int st_pctl_dt_parse_groups(struct device_node *np,
>  	struct device *dev = info->dev;
>  	struct st_pinconf *conf;
>  	struct device_node *pins;
> +	phandle bank;
> +	unsigned int offset;
>  	int i = 0, npins = 0, nr_props, ret = 0;
>  
>  	pins = of_get_child_by_name(np, "st,pins");
> @@ -1214,9 +1240,9 @@ static int st_pctl_dt_parse_groups(struct device_node *np,
>  		conf = &grp->pin_conf[i];
>  
>  		/* bank & offset */
> -		be32_to_cpup(list++);
> -		be32_to_cpup(list++);
> -		conf->pin = of_get_named_gpio(pins, pp->name, 0);
> +		bank = be32_to_cpup(list++);
> +		offset = be32_to_cpup(list++);
> +		conf->pin = st_pctl_dt_calculate_pin(info, bank, offset);
>  		conf->name = pp->name;
>  		grp->pins[i] = conf->pin;
>  		/* mux */

I tested it on stih410-b2260 board

Tested-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

Thanks
Patrice