gpio / ACPI: Allocate ACPI specific data directly in acpi_gpiochip_add()

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.

In addition we embed evt_pins member directly to the structure instead of
having it as a pointer. This simplifies the code a bit since we don't need
to check against NULL.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 64 insertions, 42 deletions

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index b7db098ba060..5c0cf1d76c8b 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
+ * @acpi_gpio:      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
@@ -96,12 +101,12 @@ 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 *acpi_gpio)
 {
         struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+        struct gpio_chip *chip = acpi_gpio->chip;
         struct acpi_resource *res;
         acpi_handle handle, evt_handle;
-        struct list_head *evt_pins = NULL;
         acpi_status status;
         unsigned int pin;
         int irq, ret;
@@ -114,23 +119,7 @@ static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
         if (!handle)
                 return;
 
-        status = acpi_get_event_resources(handle, &buf);
-        if (ACPI_FAILURE(status))
-                return;
-
-        status = acpi_get_handle(handle, "_EVT", &evt_handle);
-        if (ACPI_SUCCESS(status)) {
-                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;
-                        }
-                }
-        }
+        INIT_LIST_HEAD(&acpi_gpio->evt_pins);
 
         /*
          * If a GPIO interrupt has an ACPI event handler method, or _EVT is
@@ -167,14 +156,18 @@ static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
                                 data = ev_handle;
                         }
                 }
-                if (!handler && evt_pins) {
+                if (!handler) {
                         struct acpi_gpio_evt_pin *evt_pin;
 
+                        status = acpi_get_handle(handle, "_EVT", &evt_handle);
+                        if (ACPI_FAILURE(status))
+                                continue
+
                         evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
                         if (!evt_pin)
                                 continue;
 
-                        list_add_tail(&evt_pin->node, evt_pins);
+                        list_add_tail(&evt_pin->node, &acpi_gpio->evt_pins);
                         evt_pin->evt_handle = evt_handle;
                         evt_pin->pin = pin;
                         evt_pin->irq = irq;
@@ -197,39 +190,27 @@ static void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 
 /**
  * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
- * @chip:      gpio chip
+ * @acpi_gpio:      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 *acpi_gpio)
 {
-        acpi_handle handle;
-        acpi_status status;
-        struct list_head *evt_pins;
         struct acpi_gpio_evt_pin *evt_pin, *ep;
+        struct gpio_chip *chip = acpi_gpio->chip;
 
         if (!chip->dev || !chip->to_irq)
                 return;
 
-        handle = ACPI_HANDLE(chip->dev);
-        if (!handle)
-                return;
-
-        status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
-        if (ACPI_FAILURE(status))
-                return;
-
-        list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
+        list_for_each_entry_safe_reverse(evt_pin, ep, &acpi_gpio->evt_pins,
+                                         node) {
                 devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
                 list_del(&evt_pin->node);
                 kfree(evt_pin);
         }
-
-        acpi_detach_data(handle, acpi_gpio_evt_dh);
-        kfree(evt_pins);
 }
 
 struct acpi_gpio_lookup {
@@ -312,10 +293,51 @@ 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 *acpi_gpio;
+        acpi_handle handle;
+        acpi_status status;
+
+        handle = ACPI_HANDLE(chip->dev);
+        if (!handle)
+                return;
+
+        acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
+        if (!acpi_gpio) {
+                dev_err(chip->dev,
+                        "Failed to allocate memory for ACPI GPIO chip\n");
+                return;
+        }
+
+        acpi_gpio->chip = chip;
+
+        status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
+        if (ACPI_FAILURE(status)) {
+                dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
+                kfree(acpi_gpio);
+                return;
+        }
+
+        acpi_gpiochip_request_interrupts(acpi_gpio);
 }
 
 void acpi_gpiochip_remove(struct gpio_chip *chip)
 {
-        acpi_gpiochip_free_interrupts(chip);
+        struct acpi_gpio_chip *acpi_gpio;
+        acpi_handle handle;
+        acpi_status status;
+
+        handle = ACPI_HANDLE(chip->dev);
+        if (!handle)
+                return;
+
+        status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
+        if (ACPI_FAILURE(status)) {
+                dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
+                return;
+        }
+
+        acpi_gpiochip_free_interrupts(acpi_gpio);
+
+        acpi_detach_data(handle, acpi_gpio_chip_dh);
+        kfree(acpi_gpio);
 }