genirq/irq_sim: Add a devres variant of irq_sim_init()

Add a resource managed version of irq_sim_init(). This can be
conveniently used in device drivers.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Link: http://lkml.kernel.org/r/20170814145318.6495-3-brgl@bgdev.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Documentation/driver-model/devres.txt

@@ -312,6 +312,7 @@ IRQ
   devm_irq_alloc_descs_from()
   devm_irq_alloc_generic_chip()
   devm_irq_setup_generic_chip()
+  devm_irq_sim_init()
 
 LED
   devm_led_classdev_register()

include/linux/irq_sim.h

@@ -10,6 +10,7 @@
  */
 
 #include <linux/irq_work.h>
+#include <linux/device.h>
 
 /*
  * Provides a framework for allocating simulated interrupts which can be
@@ -34,6 +35,8 @@ struct irq_sim {
 };
 
 int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs);
+int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
+		      unsigned int num_irqs);
 void irq_sim_fini(struct irq_sim *sim);
 void irq_sim_fire(struct irq_sim *sim, unsigned int offset);
 int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset);

kernel/irq/irq_sim.c

@@ -10,6 +10,10 @@
 #include <linux/irq_sim.h>
 #include <linux/irq.h>
 
+struct irq_sim_devres {
+	struct irq_sim		*sim;
+};
+
 static void irq_sim_irqmask(struct irq_data *data)
 {
 	struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
@@ -92,6 +96,45 @@ void irq_sim_fini(struct irq_sim *sim)
 }
 EXPORT_SYMBOL_GPL(irq_sim_fini);
 
+static void devm_irq_sim_release(struct device *dev, void *res)
+{
+	struct irq_sim_devres *this = res;
+
+	irq_sim_fini(this->sim);
+}
+
+/**
+ * irq_sim_init - Initialize the interrupt simulator for a managed device.
+ *
+ * @dev:        Device to initialize the simulator object for.
+ * @sim:        The interrupt simulator object to initialize.
+ * @num_irqs:   Number of interrupts to allocate
+ *
+ * Returns 0 on success and a negative error number on failure.
+ */
+int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
+		      unsigned int num_irqs)
+{
+	struct irq_sim_devres *dr;
+	int rv;
+
+	dr = devres_alloc(devm_irq_sim_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	rv = irq_sim_init(sim, num_irqs);
+	if (rv) {
+		devres_free(dr);
+		return rv;
+	}
+
+	dr->sim = sim;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_irq_sim_init);
+
 /**
  * irq_sim_fire - Enqueue an interrupt.
  *