[PATCH 1/2] irqchip: imx-intmux: add system PM support

[Joakim Zhang <qiangqing.zhang@nxp.com>]

Add system PM support for intmux interrupt controller.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/irqchip/irq-imx-intmux.c | 59 ++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/irqchip/irq-imx-intmux.c b/drivers/irqchip/irq-imx-intmux.c
index c27577c81126..6095f76c4f0d 100644
--- a/drivers/irqchip/irq-imx-intmux.c
+++ b/drivers/irqchip/irq-imx-intmux.c
@@ -70,6 +70,9 @@ struct intmux_data {
 	void __iomem			*regs;
 	struct clk			*ipg_clk;
 	int				channum;
+#ifdef CONFIG_PM
+	unsigned int			*saved_reg;
+#endif
 	struct intmux_irqchip_data	irqchip_data[];
 };
 
@@ -232,6 +235,15 @@ static int imx_intmux_probe(struct platform_device *pdev)
 	data->channum = channum;
 	raw_spin_lock_init(&data->lock);
 
+	if (IS_ENABLED(CONFIG_PM)) {
+		/* save CHANIER register */
+		data->saved_reg = devm_kzalloc(&pdev->dev,
+					       sizeof(unsigned int) * channum,
+					       GFP_KERNEL);
+		if (!data->saved_reg)
+			return -ENOMEM;
+	}
+
 	ret = clk_prepare_enable(data->ipg_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
@@ -293,6 +305,53 @@ static int imx_intmux_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static void imx_intmux_save_regs(struct intmux_data *data)
+{
+	int i;
+
+	for (i = 0; i < data->channum; i++)
+		data->saved_reg[i] = readl_relaxed(data->regs + CHANIER(i));
+}
+
+static void imx_intmux_restore_regs(struct intmux_data *data)
+{
+	int i;
+
+	for (i = 0; i < data->channum; i++)
+		writel_relaxed(data->saved_reg[i], data->regs + CHANIER(i));
+}
+
+static int imx_intmux_suspend(struct device *dev)
+{
+	struct intmux_data *data = dev_get_drvdata(dev);
+
+	imx_intmux_save_regs(data);
+	clk_disable_unprepare(data->ipg_clk);
+
+	return 0;
+}
+
+static int imx_intmux_resume(struct device *dev)
+{
+	struct intmux_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(data->ipg_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
+		return ret;
+	}
+	imx_intmux_restore_regs(data);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops imx_intmux_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_intmux_suspend, imx_intmux_resume)
+};
+
 static const struct of_device_id imx_intmux_id[] = {
 	{ .compatible = "fsl,imx-intmux", },
 	{ /* sentinel */ },
-- 
2.17.1