ACPI / gpio: Add hogging support

[karo-tx-linux.git] / drivers / gpio / gpiolib-acpi.c

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 700ea6ad609b5b824ed4dbdd2d1ecb9f79023d68..4f46982ce982fabfb63727f10878f928a60bd9bb 100644 (file)
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -857,6 +857,76 @@ static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
        }
 }
 
+struct gpio_desc *acpi_gpiochip_parse_own_gpio(struct acpi_gpio_chip *achip,
+       struct fwnode_handle *fwnode, const char **name, unsigned int *lflags,
+       unsigned int *dflags)
+{
+       struct gpio_chip *chip = achip->chip;
+       struct gpio_desc *desc;
+       u32 gpios[2];
+       int ret;
+
+       ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,
+                                            ARRAY_SIZE(gpios));
+       if (ret < 0)
+               return ERR_PTR(ret);
+
+       ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
+       if (ret < 0)
+               return ERR_PTR(ret);
+
+       desc = gpiochip_get_desc(chip, ret);
+       if (IS_ERR(desc))
+               return desc;
+
+       *lflags = 0;
+       *dflags = 0;
+       *name = NULL;
+
+       if (gpios[1])
+               *lflags |= GPIO_ACTIVE_LOW;
+
+       if (fwnode_property_present(fwnode, "input"))
+               *dflags |= GPIOD_IN;
+       else if (fwnode_property_present(fwnode, "output-low"))
+               *dflags |= GPIOD_OUT_LOW;
+       else if (fwnode_property_present(fwnode, "output-high"))
+               *dflags |= GPIOD_OUT_HIGH;
+       else
+               return ERR_PTR(-EINVAL);
+
+       fwnode_property_read_string(fwnode, "line-name", name);
+
+       return desc;
+}
+
+static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
+{
+       struct gpio_chip *chip = achip->chip;
+       struct fwnode_handle *fwnode;
+
+       device_for_each_child_node(chip->parent, fwnode) {
+               unsigned int lflags, dflags;
+               struct gpio_desc *desc;
+               const char *name;
+               int ret;
+
+               if (!fwnode_property_present(fwnode, "gpio-hog"))
+                       continue;
+
+               desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,
+                                                   &lflags, &dflags);
+               if (IS_ERR(desc))
+                       continue;
+
+               ret = gpiod_hog(desc, name, lflags, dflags);
+               if (ret) {
+                       dev_err(chip->parent, "Failed to hog GPIO\n");
+                       return;
+               }
+       }
+}
+
 void acpi_gpiochip_add(struct gpio_chip *chip)
 {
        struct acpi_gpio_chip *acpi_gpio;
@@ -888,6 +958,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
        }
 
        acpi_gpiochip_request_regions(acpi_gpio);
+       acpi_gpiochip_scan_gpios(acpi_gpio);
        acpi_walk_dep_device_list(handle);
 }