Hi Shawn,

thank you for the comments.

Am Mittwoch, den 05.03.2014, 14:56 +0800 schrieb Shawn Guo:

quoted

diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 33567aa..3c58f2e 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig

@@ -808,6 +808,7 @@ config SOC_IMX6Q
 	select PL310_ERRATA_727915 if CACHE_PL310
 	select PL310_ERRATA_769419 if CACHE_PL310
 	select PM_OPP if PM
+	select PM_GENERIC_DOMAINS if PM

Would it make more sense to have HAVE_IMX_GPC select it instead?

Yes, I'll change that.

quoted

+#include <linux/pm_clock.h>

Is this header still needed?

No, will remove.

[...]

quoted

+struct pu_domain {
+	struct generic_pm_domain base;
+	struct regulator *reg;
+	struct clk *clk[6];

Define a macro for this number?

#define GPC_CLK_MAX   6

[...]

quoted

+static int imx_gpc_probe(struct platform_device *pdev)
+{
+	struct regulator *pu_reg;
+	struct clk *clk;
+	bool is_off;
+	int ret, i;
+
+	pu_reg = devm_regulator_get(&pdev->dev, "pu");
+	if (IS_ERR(pu_reg)) {
+		ret = PTR_ERR(pu_reg);
+		dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
+		return ret;
+	}
+
+	/* The regulator is initially enabled */
+	ret = regulator_enable(pu_reg);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to enable pu regulator: %d\n", ret);
+		return ret;
+	}
+	imx6q_pu_domain.base.of_node = pdev->dev.of_node;

How does this work with !CONFIG_PM build?

Since I removed the regulator-always-on property from the PU regulator
in the device tree, if CONFIG_PM is disabled, we have to request and
enable pu_reg here. Otherwise the regulator framework will helpfully
turn it off (imx6q-cpufreq never enables pu_reg).
With the PU regulator disabled, the system would hang as soon as the
CODA VPU or one of the Vivante GPU cores is accessed if !CONFIG_PM.

quoted

+	imx6q_pu_domain.reg = pu_reg;
+
+	for (i = 0; ; i++) {
+		clk = of_clk_get(pdev->dev.of_node, i);
+		if (IS_ERR(clk))
+			break;

Also, I should probably add
+		if (i >= GPC_CLK_MAX) {
+			dev_err(&pdev->dev, "more than %d clocks\n",
+				GPC_CLK_MAX);
+			return -EINVAL;
+		}
here.

quoted

+		imx6q_pu_domain.clk[i] = clk;
+	}
+	imx6q_pu_domain.num_clks = i;

[...]

regards
Philipp