[PATCH 2/6] gpio / ACPI: Allocate ACPI specific data directly in acpi_gpiochip_add()

[Mika Westerberg <mika.westerberg@linux.intel.com>]

We are going to add more ACPI specific data to accompany GPIO chip so
instead of allocating it per each use-case we allocate it once when
acpi_gpiochip_add() is called and release it when acpi_gpiochip_remove() is
called.

Doing this allows us to add more ACPI specific data by merely adding new
fields to struct acpi_gpio_chip.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/gpio/gpiolib-acpi.c | 83 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 59 insertions(+), 24 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index b7db098ba060..5f5f107c2099 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -26,6 +26,11 @@ struct acpi_gpio_evt_pin {
 	unsigned int irq;
 };
 
+struct acpi_gpio_chip {
+	struct gpio_chip *chip;
+	struct list_head *evt_pins;
+};
+
 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
 {
 	if (!gc->dev)
@@ -81,14 +86,14 @@ static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static void acpi_gpio_evt_dh(acpi_handle handle, void *data)
+static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
 {
 	/* The address of this function is used as a key. */
 }
 
 /**
  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
- * @chip:      gpio chip
+ * @achip:      ACPI GPIO chip
  *
  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
  * handled by ACPI event methods which need to be called from the GPIO
@@ -96,9 +101,10 @@ static void acpi_gpio_evt_dh(acpi_handle handle, void *data)
  * gpio pins have acpi event methods and assigns interrupt handlers that calls
  * the acpi event methods for those pins.
  */
-static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
+static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *achip)
 {
 	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct gpio_chip *chip = achip->chip;
 	struct acpi_resource *res;
 	acpi_handle handle, evt_handle;
 	struct list_head *evt_pins = NULL;
@@ -123,12 +129,7 @@ static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 		evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
 		if (evt_pins) {
 			INIT_LIST_HEAD(evt_pins);
-			status = acpi_attach_data(handle, acpi_gpio_evt_dh,
-						  evt_pins);
-			if (ACPI_FAILURE(status)) {
-				kfree(evt_pins);
-				evt_pins = NULL;
-			}
+			achip->evt_pins = evt_pins;
 		}
 	}
 
@@ -197,30 +198,24 @@ static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 
 /**
  * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
- * @chip:      gpio chip
+ * @achip:      ACPI GPIO chip
  *
  * Free interrupts associated with the _EVT method for the given GPIO chip.
  *
  * The remaining ACPI event interrupts associated with the chip are freed
  * automatically.
  */
-static void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
+static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *achip)
 {
-	acpi_handle handle;
-	acpi_status status;
 	struct list_head *evt_pins;
 	struct acpi_gpio_evt_pin *evt_pin, *ep;
+	struct gpio_chip *chip = achip->chip;
 
-	if (!chip->dev || !chip->to_irq)
-		return;
-
-	handle = ACPI_HANDLE(chip->dev);
-	if (!handle)
+	if (!chip->dev || !chip->to_irq || !achip->evt_pins)
 		return;
 
-	status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
-	if (ACPI_FAILURE(status))
-		return;
+	evt_pins = achip->evt_pins;
+	achip->evt_pins = NULL;
 
 	list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
 		devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
@@ -228,7 +223,6 @@ static void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 		kfree(evt_pin);
 	}
 
-	acpi_detach_data(handle, acpi_gpio_evt_dh);
 	kfree(evt_pins);
 }
 
@@ -312,10 +306,51 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
 
 void acpi_gpiochip_add(struct gpio_chip *chip)
 {
-	acpi_gpiochip_request_interrupts(chip);
+	struct acpi_gpio_chip *achip;
+	acpi_handle handle;
+	acpi_status status;
+
+	handle = ACPI_HANDLE(chip->dev);
+	if (!handle)
+		return;
+
+	achip = kzalloc(sizeof(*achip), GFP_KERNEL);
+	if (!achip) {
+		dev_err(chip->dev,
+			"Failed to allocate memory for ACPI GPIO chip\n");
+		return;
+	}
+
+	achip->chip = chip;
+
+	status = acpi_attach_data(handle, acpi_gpio_chip_dh, achip);
+	if (ACPI_FAILURE(status)) {
+		dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
+		kfree(achip);
+		return;
+	}
+
+	acpi_gpiochip_request_interrupts(achip);
 }
 
 void acpi_gpiochip_remove(struct gpio_chip *chip)
 {
-	acpi_gpiochip_free_interrupts(chip);
+	struct acpi_gpio_chip *achip;
+	acpi_handle handle;
+	acpi_status status;
+
+	handle = ACPI_HANDLE(chip->dev);
+	if (!handle)
+		return;
+
+	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&achip);
+	if (ACPI_FAILURE(status)) {
+		dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
+		return;
+	}
+
+	acpi_gpiochip_free_interrupts(achip);
+
+	acpi_detach_data(handle, acpi_gpio_chip_dh);
+	kfree(achip);
 }
-- 
1.9.0.rc3