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linux/named-gpio-export: add support for OPEN_DRAIN and OPEN_SOURCE flag

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This change makes it possible to use the GPIO_OPEN_DRAIN /
GPIO_OPEN_SOURCE Flags when exporting GPIOs via dts.

We need to emulate the open-source or open-drain functionalities for the
initial value, because the used functions (gpiod_direction_output_raw)
do not take this into account.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
This commit is contained in:
Martin Schiller 2023-08-04 12:59:03 +02:00 committed by Hauke Mehrtens
parent 7770d08e2b
commit 0af88d2512
2 changed files with 66 additions and 10 deletions
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38
target/linux/generic/hack-5.15/800-GPIO-add-named-gpio-exports.patch
View file

@ -15,7 +15,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
#include "gpiolib.h" #include "gpiolib.h"
#include "gpiolib-of.h" #include "gpiolib-of.h"
@@ -1059,3 +1061,72 @@ void of_gpio_dev_init(struct gpio_chip * @@ -1059,3 +1061,100 @@ void of_gpio_dev_init(struct gpio_chip *
else else
gc->of_node = gdev->dev.of_node; gc->of_node = gdev->dev.of_node;
} }
@ -47,6 +47,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ max_gpio = of_gpio_count(cnp); + max_gpio = of_gpio_count(cnp);
+ +
+ for (i = 0; i < max_gpio; i++) { + for (i = 0; i < max_gpio; i++) {
+ struct gpio_desc *desc;
+ unsigned flags = 0; + unsigned flags = 0;
+ enum of_gpio_flags of_flags; + enum of_gpio_flags of_flags;
+ +
@ -54,17 +55,44 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ if (!gpio_is_valid(gpio)) + if (!gpio_is_valid(gpio))
+ return gpio; + return gpio;
+ +
+ if (of_flags == OF_GPIO_ACTIVE_LOW) + if (of_flags & OF_GPIO_ACTIVE_LOW)
+ flags |= GPIOF_ACTIVE_LOW; + flags |= GPIOF_ACTIVE_LOW;
+ +
+ if (!of_property_read_u32(cnp, "gpio-export,output", &val)) + if (!of_property_read_u32(cnp, "gpio-export,output", &val)) {
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; + if (of_flags & OF_GPIO_SINGLE_ENDED) {
+ else + /*
+ * As gpiod_direction_output_raw() is used, we
+ * need to emulate open drain or open source here.
+ */
+ if (of_flags & OF_GPIO_OPEN_DRAIN) {
+ flags |= GPIOF_OPEN_DRAIN;
+ flags |= val ? GPIOF_IN : GPIOF_OUT_INIT_LOW;
+ } else {
+ flags |= GPIOF_OPEN_SOURCE;
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_IN;
+ }
+ } else {
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ }
+ } else {
+ flags |= GPIOF_IN; + flags |= GPIOF_IN;
+ }
+ +
+ if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np))) + if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np)))
+ continue; + continue;
+ +
+ /*
+ * When emulating open-source or open-drain functionalities by not
+ * actively driving the line (setting mode to input) we still need to
+ * set the IS_OUT flag or otherwise we won't be able to set the line
+ * value anymore.
+ */
+ if ((flags & GPIOF_IN) &&
+ ((flags & GPIOF_OPEN_DRAIN) || (flags & GPIOF_OPEN_SOURCE))) {
+ desc = gpio_to_desc(gpio);
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+
+ dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change"); + dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
+ gpio_export_with_name(gpio, dmc, name); + gpio_export_with_name(gpio, dmc, name);
+ nb++; + nb++;

38
target/linux/generic/hack-6.1/800-GPIO-add-named-gpio-exports.patch
View file

@ -15,7 +15,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
#include "gpiolib.h" #include "gpiolib.h"
#include "gpiolib-of.h" #include "gpiolib-of.h"
@@ -1030,3 +1032,72 @@ void of_gpio_dev_init(struct gpio_chip * @@ -1030,3 +1032,100 @@ void of_gpio_dev_init(struct gpio_chip *
else else
gc->of_node = gdev->dev.of_node; gc->of_node = gdev->dev.of_node;
} }
@ -47,6 +47,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ max_gpio = of_gpio_count(cnp); + max_gpio = of_gpio_count(cnp);
+ +
+ for (i = 0; i < max_gpio; i++) { + for (i = 0; i < max_gpio; i++) {
+ struct gpio_desc *desc;
+ unsigned flags = 0; + unsigned flags = 0;
+ enum of_gpio_flags of_flags; + enum of_gpio_flags of_flags;
+ +
@ -54,17 +55,44 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
+ if (!gpio_is_valid(gpio)) + if (!gpio_is_valid(gpio))
+ return gpio; + return gpio;
+ +
+ if (of_flags == OF_GPIO_ACTIVE_LOW) + if (of_flags & OF_GPIO_ACTIVE_LOW)
+ flags |= GPIOF_ACTIVE_LOW; + flags |= GPIOF_ACTIVE_LOW;
+ +
+ if (!of_property_read_u32(cnp, "gpio-export,output", &val)) + if (!of_property_read_u32(cnp, "gpio-export,output", &val)) {
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; + if (of_flags & OF_GPIO_SINGLE_ENDED) {
+ else + /*
+ * As gpiod_direction_output_raw() is used, we
+ * need to emulate open drain or open source here.
+ */
+ if (of_flags & OF_GPIO_OPEN_DRAIN) {
+ flags |= GPIOF_OPEN_DRAIN;
+ flags |= val ? GPIOF_IN : GPIOF_OUT_INIT_LOW;
+ } else {
+ flags |= GPIOF_OPEN_SOURCE;
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_IN;
+ }
+ } else {
+ flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ }
+ } else {
+ flags |= GPIOF_IN; + flags |= GPIOF_IN;
+ }
+ +
+ if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np))) + if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np)))
+ continue; + continue;
+ +
+ /*
+ * When emulating open-source or open-drain functionalities by not
+ * actively driving the line (setting mode to input) we still need to
+ * set the IS_OUT flag or otherwise we won't be able to set the line
+ * value anymore.
+ */
+ if ((flags & GPIOF_IN) &&
+ ((flags & GPIOF_OPEN_DRAIN) || (flags & GPIOF_OPEN_SOURCE))) {
+ desc = gpio_to_desc(gpio);
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+
+ dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change"); + dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
+ gpio_export_with_name(gpio, dmc, name); + gpio_export_with_name(gpio, dmc, name);
+ nb++; + nb++;