Merge tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...

[sfrench/cifs-2.6.git] / drivers / gpio / gpiolib-acpi.c

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 79271e08eea555bba500245d7ad912572d218c82..2b1a7b455aa83303410a34818ece422af6487392 100644 (file)
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * ACPI helpers for GPIO API
  *
  * Copyright (C) 2012, Intel Corporation
  * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
  *          Mika Westerberg <mika.westerberg@linux.intel.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/errno.h>
@@ -24,7 +21,6 @@
 
 struct acpi_gpio_event {
        struct list_head node;
-       struct list_head initial_sync_list;
        acpi_handle handle;
        unsigned int pin;
        unsigned int irq;
@@ -48,10 +44,19 @@ struct acpi_gpio_chip {
        struct mutex conn_lock;
        struct gpio_chip *chip;
        struct list_head events;
+       struct list_head deferred_req_irqs_list_entry;
 };
 
-static LIST_HEAD(acpi_gpio_initial_sync_list);
-static DEFINE_MUTEX(acpi_gpio_initial_sync_list_lock);
+/*
+ * For gpiochips which call acpi_gpiochip_request_interrupts() before late_init
+ * (so builtin drivers) we register the ACPI GpioInt event handlers from a
+ * late_initcall_sync handler, so that other builtin drivers can register their
+ * OpRegions before the event handlers can run.  This list contains gpiochips
+ * for which the acpi_gpiochip_request_interrupts() has been deferred.
+ */
+static DEFINE_MUTEX(acpi_gpio_deferred_req_irqs_lock);
+static LIST_HEAD(acpi_gpio_deferred_req_irqs_list);
+static bool acpi_gpio_deferred_req_irqs_done;
 
 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
 {
@@ -88,21 +93,6 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
        return gpiochip_get_desc(chip, pin);
 }
 
-static void acpi_gpio_add_to_initial_sync_list(struct acpi_gpio_event *event)
-{
-       mutex_lock(&acpi_gpio_initial_sync_list_lock);
-       list_add(&event->initial_sync_list, &acpi_gpio_initial_sync_list);
-       mutex_unlock(&acpi_gpio_initial_sync_list_lock);
-}
-
-static void acpi_gpio_del_from_initial_sync_list(struct acpi_gpio_event *event)
-{
-       mutex_lock(&acpi_gpio_initial_sync_list_lock);
-       if (!list_empty(&event->initial_sync_list))
-               list_del_init(&event->initial_sync_list);
-       mutex_unlock(&acpi_gpio_initial_sync_list_lock);
-}
-
 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
 {
        struct acpi_gpio_event *event = data;
@@ -185,7 +175,7 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 
        gpiod_direction_input(desc);
 
-       value = gpiod_get_value(desc);
+       value = gpiod_get_value_cansleep(desc);
 
        ret = gpiochip_lock_as_irq(chip, pin);
        if (ret) {
@@ -228,7 +218,6 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
        event->irq = irq;
        event->pin = pin;
        event->desc = desc;
-       INIT_LIST_HEAD(&event->initial_sync_list);
 
        ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
                                   "ACPI:Event", event);
@@ -250,10 +239,9 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
         * may refer to OperationRegions from other (builtin) drivers which
         * may be probed after us.
         */
-       if (handler == acpi_gpio_irq_handler &&
-           (((irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
-            ((irqflags & IRQF_TRIGGER_FALLING) && value == 0)))
-               acpi_gpio_add_to_initial_sync_list(event);
+       if (((irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
+           ((irqflags & IRQF_TRIGGER_FALLING) && value == 0))
+               handler(event->irq, event);
 
        return AE_OK;
 
@@ -282,6 +270,7 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
        struct acpi_gpio_chip *acpi_gpio;
        acpi_handle handle;
        acpi_status status;
+       bool defer;
 
        if (!chip->parent || !chip->to_irq)
                return;
@@ -294,6 +283,16 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
        if (ACPI_FAILURE(status))
                return;
 
+       mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
+       defer = !acpi_gpio_deferred_req_irqs_done;
+       if (defer)
+               list_add(&acpi_gpio->deferred_req_irqs_list_entry,
+                        &acpi_gpio_deferred_req_irqs_list);
+       mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
+
+       if (defer)
+               return;
+
        acpi_walk_resources(handle, "_AEI",
                            acpi_gpiochip_request_interrupt, acpi_gpio);
 }
@@ -324,11 +323,14 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
        if (ACPI_FAILURE(status))
                return;
 
+       mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
+       if (!list_empty(&acpi_gpio->deferred_req_irqs_list_entry))
+               list_del_init(&acpi_gpio->deferred_req_irqs_list_entry);
+       mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
+
        list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
                struct gpio_desc *desc;
 
-               acpi_gpio_del_from_initial_sync_list(event);
-
                if (irqd_is_wakeup_set(irq_get_irq_data(event->irq)))
                        disable_irq_wake(event->irq);
 
@@ -1051,6 +1053,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
 
        acpi_gpio->chip = chip;
        INIT_LIST_HEAD(&acpi_gpio->events);
+       INIT_LIST_HEAD(&acpi_gpio->deferred_req_irqs_list_entry);
 
        status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
        if (ACPI_FAILURE(status)) {
@@ -1197,20 +1200,28 @@ bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
        return con_id == NULL;
 }
 
-/* Sync the initial state of handlers after all builtin drivers have probed */
-static int acpi_gpio_initial_sync(void)
+/* Run deferred acpi_gpiochip_request_interrupts() */
+static int acpi_gpio_handle_deferred_request_interrupts(void)
 {
-       struct acpi_gpio_event *event, *ep;
+       struct acpi_gpio_chip *acpi_gpio, *tmp;
+
+       mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
+       list_for_each_entry_safe(acpi_gpio, tmp,
+                                &acpi_gpio_deferred_req_irqs_list,
+                                deferred_req_irqs_list_entry) {
+               acpi_handle handle;
 
-       mutex_lock(&acpi_gpio_initial_sync_list_lock);
-       list_for_each_entry_safe(event, ep, &acpi_gpio_initial_sync_list,
-                                initial_sync_list) {
-               acpi_evaluate_object(event->handle, NULL, NULL, NULL);
-               list_del_init(&event->initial_sync_list);
+               handle = ACPI_HANDLE(acpi_gpio->chip->parent);
+               acpi_walk_resources(handle, "_AEI",
+                                   acpi_gpiochip_request_interrupt, acpi_gpio);
+
+               list_del_init(&acpi_gpio->deferred_req_irqs_list_entry);
        }
-       mutex_unlock(&acpi_gpio_initial_sync_list_lock);
+
+       acpi_gpio_deferred_req_irqs_done = true;
+       mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
 
        return 0;
 }
 /* We must use _sync so that this runs after the first deferred_probe run */
-late_initcall_sync(acpi_gpio_initial_sync);
+late_initcall_sync(acpi_gpio_handle_deferred_request_interrupts);