[PATCH 1/5] irqchip/gic-pm: add driver remove support

[Sameer Pujar]

This is a preparatory patch for using irq-gic-pm driver as module and thus
implement remove() call for the driver. Details of remove() are as below,

 * pm_runtime_force_suspend() is added to balance runtime PM, otherwise
   following is seen: "agic-controller: Unbalanced pm_runtime_enable!"
 * Function gic_teardown() is exported from gic driver and called in remove
   to perform io unmap.
 * pm_clk_destroy() to free clock resources
 * irq is unmapped and freed with irq_dispose_mapping()

Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
---
 drivers/irqchip/irq-gic-pm.c    | 37 ++++++++++++++++++++++++++++++++-----
 drivers/irqchip/irq-gic.c       |  3 ++-
 include/linux/irqchip/arm-gic.h |  2 ++
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-gic-pm.c b/drivers/irqchip/irq-gic-pm.c
index ecafd29..56a785f 100644
--- a/drivers/irqchip/irq-gic-pm.c
+++ b/drivers/irqchip/irq-gic-pm.c
@@ -28,9 +28,15 @@ struct gic_clk_data {
 	const char *const *clocks;
 };
 
+struct gic_chip_pm {
+	struct gic_chip_data *chip_data;
+	int irq;
+};
+
 static int gic_runtime_resume(struct device *dev)
 {
-	struct gic_chip_data *gic = dev_get_drvdata(dev);
+	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
+	struct gic_chip_data *gic = chip_pm->chip_data;
 	int ret;
 
 	ret = pm_clk_resume(dev);
@@ -54,7 +60,8 @@ static int gic_runtime_resume(struct device *dev)
 
 static int gic_runtime_suspend(struct device *dev)
 {
-	struct gic_chip_data *gic = dev_get_drvdata(dev);
+	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
+	struct gic_chip_data *gic = chip_pm->chip_data;
 
 	gic_dist_save(gic);
 	gic_cpu_save(gic);
@@ -91,9 +98,14 @@ static int gic_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct gic_clk_data *data;
-	struct gic_chip_data *gic;
+	struct gic_chip_pm *chip_pm;
 	int ret, irq;
 
+	chip_pm = devm_kzalloc(dev, sizeof(struct gic_chip_pm),
+			       GFP_KERNEL);
+	if (!chip_pm)
+		return -ENOMEM;
+
 	data = of_device_get_match_data(&pdev->dev);
 	if (!data) {
 		dev_err(&pdev->dev, "no device match found\n");
@@ -116,14 +128,15 @@ static int gic_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto rpm_disable;
 
-	ret = gic_of_init_child(dev, &gic, irq);
+	ret = gic_of_init_child(dev, &chip_pm->chip_data, irq);
 	if (ret)
 		goto rpm_put;
 
-	platform_set_drvdata(pdev, gic);
+	platform_set_drvdata(pdev, chip_pm);
 
 	pm_runtime_put(dev);
 
+	chip_pm->irq = irq;
 	dev_info(dev, "GIC IRQ controller registered\n");
 
 	return 0;
@@ -139,6 +152,19 @@ static int gic_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int gic_remove(struct platform_device *pdev)
+{
+	struct gic_chip_pm *chip_pm = dev_get_drvdata(&pdev->dev);
+	struct gic_chip_data *gic = chip_pm->chip_data;
+
+	pm_runtime_force_suspend(&pdev->dev);
+	gic_teardown(gic);
+	pm_clk_destroy(&pdev->dev);
+	irq_dispose_mapping(chip_pm->irq);
+
+	return 0;
+}
+
 static const struct dev_pm_ops gic_pm_ops = {
 	SET_RUNTIME_PM_OPS(gic_runtime_suspend,
 			   gic_runtime_resume, NULL)
@@ -161,6 +187,7 @@ MODULE_DEVICE_TABLE(of, gic_match);
 
 static struct platform_driver gic_driver = {
 	.probe		= gic_probe,
+	.remove		= gic_remove,
 	.driver		= {
 		.name	= "gic",
 		.of_match_table	= gic_match,
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index ba2a37a..f88018b 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1259,7 +1259,7 @@ void __init gic_init(unsigned int gic_nr, int irq_start,
 	__gic_init_bases(gic, irq_start, NULL);
 }
 
-static void gic_teardown(struct gic_chip_data *gic)
+void gic_teardown(struct gic_chip_data *gic)
 {
 	if (WARN_ON(!gic))
 		return;
@@ -1269,6 +1269,7 @@ static void gic_teardown(struct gic_chip_data *gic)
 	if (gic->raw_cpu_base)
 		iounmap(gic->raw_cpu_base);
 }
+EXPORT_SYMBOL_GPL(gic_teardown);
 
 #ifdef CONFIG_OF
 static int gic_cnt __initdata;
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 6261790..f790232 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -161,6 +161,8 @@ int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int irq);
 void gic_init(unsigned int nr, int start,
 	      void __iomem *dist , void __iomem *cpu);
 
+void gic_teardown(struct gic_chip_data *gic);
+
 int gicv2m_init(struct fwnode_handle *parent_handle,
 		struct irq_domain *parent);
 
-- 
2.7.4