MLK-16909 irqchip: imx-irqsteer: restore registers after power off

Once irqsteer controller is power off during suspend, the registers
are lost, it should restore the registers after resume back.

BuildInfo:
 - SCFW a479ff78, IMX-MKIMAGE ff9860c5, ATF 923651a
 - U-Boot 2017.03-00691-g96cf020

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Tested-by: Pandy.gao <pandy.gao@nxp.com>
Acked-by: Pandy.gao <pandy.gao@nxp.com>

diff --git a/drivers/irqchip/irq-imx-irqsteer.c b/drivers/irqchip/irq-imx-irqsteer.c
index 2e8f04a..6aa0a68 100644 (file)
--- a/drivers/irqchip/irq-imx-irqsteer.c
+++ b/drivers/irqchip/irq-imx-irqsteer.c
@@ -33,6 +33,7 @@ struct irqsteer_irqchip_data {
        int channum;
        int endian;     /* 0: littel endian; 1: big endian */
        struct irq_domain *domain;
+       int *saved_reg;
        unsigned int irqstat[];
 };
 
@@ -168,6 +169,10 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
        if (!irqsteer_data)
                return -ENOMEM;
 
+       irqsteer_data->saved_reg = devm_kzalloc(&pdev->dev, sizeof(int) *
+                                               (channum + 1), GFP_KERNEL);
+       if (!irqsteer_data->saved_reg)
+               return -ENOMEM;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        irqsteer_data->regs = devm_ioremap_resource(&pdev->dev, res);
@@ -235,6 +240,58 @@ static int imx_irqsteer_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static void imx_irqsteer_save_regs(struct irqsteer_irqchip_data *data)
+{
+       int num;
+
+       data->saved_reg[0] = readl_relaxed(data->regs + CHANCTRL);
+       for (num = 0; num < data->channum; num++)
+               data->saved_reg[num + 1] = readl_relaxed(data->regs + CHANMASK(num));
+}
+
+static void imx_irqsteer_restore_regs(struct irqsteer_irqchip_data *data)
+{
+       int num;
+
+       writel_relaxed(data->saved_reg[0], data->regs + CHANCTRL);
+       for (num = 0; num < data->channum; num++)
+               writel_relaxed(data->saved_reg[num + 1], data->regs + CHANMASK(num));
+}
+
+static int imx_irqsteer_suspend(struct device *dev)
+{
+       struct irqsteer_irqchip_data *irqsteer_data = dev_get_drvdata(dev);
+
+       imx_irqsteer_save_regs(irqsteer_data);
+       clk_disable_unprepare(irqsteer_data->ipg_clk);
+
+       return 0;
+}
+
+static int imx_irqsteer_resume(struct device *dev)
+{
+       struct irqsteer_irqchip_data *irqsteer_data = dev_get_drvdata(dev);
+       int ret;
+
+       ret = clk_prepare_enable(irqsteer_data->ipg_clk);
+       if (ret) {
+               dev_err(dev, "failed to enable ipg clk: %d\n", ret);
+               return ret;
+       }
+       imx_irqsteer_restore_regs(irqsteer_data);
+
+       return 0;
+}
+
+static const struct dev_pm_ops imx_irqsteer_pm_ops = {
+       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_irqsteer_suspend, imx_irqsteer_resume)
+};
+#define IMX_IRQSTEER_PM      (&imx_irqsteer_pm_ops)
+#else
+#define IMX_IRQSTEER_PM      NULL
+#endif
+
 static const struct of_device_id imx_irqsteer_id[] = {
        { .compatible = "nxp,imx-irqsteer", },
        {},
@@ -244,6 +301,7 @@ static struct platform_driver imx_irqsteer_driver = {
        .driver = {
                .name = "imx-irqsteer",
                .of_match_table = imx_irqsteer_id,
+               .pm = IMX_IRQSTEER_PM,
        },
        .probe = imx_irqsteer_probe,
        .remove = imx_irqsteer_remove,