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

From: Marc Zyngier
Date: Fri Jul 17 2020 - 04:42:01 EST


On 2020-07-16 20:32, Joakim Zhang wrote:
Add system PM support for intmux interrupt controller.

Care to be a little more descriptive?


Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
---
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;

Please use u32 for 32bit HW registers.

+#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)

Which isn't defined when !CONFIG_PM. The compiler is allowed to
bail here, and does (see the two kbuild failures).

+ 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));
+}

Please move these two trivial functions into their respective callers.

+
+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 */ },

Thanks,

M.
--
Jazz is not dead. It just smells funny...