On Tue, 2015-05-12 at 15:00 +0200, Sascha Hauer wrote:

On Mon, May 11, 2015 at 05:26:22PM +0800, YH Huang wrote:

quoted

+
+static int mtk_disp_pwm_probe(struct platform_device *pdev)
+{
+	struct mtk_disp_pwm_chip *pwm;

The struct mtk_disp_pwm_chip * is named 'mpc' in the other functions.
For consistency reasons you should do that here aswell.

I miss it! Maybe 'mdpc' is a better name for mtk_disp_pwm_chip.

quoted

+	struct resource *r;
+	int ret;
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->dev = &pdev->dev;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(pwm->mmio_base))
+		return PTR_ERR(pwm->mmio_base);
+
+	pwm->clk_main = devm_clk_get(&pdev->dev, "main");
+	if (IS_ERR(pwm->clk_main))
+		return PTR_ERR(pwm->clk_main);
+	pwm->clk_mm = devm_clk_get(&pdev->dev, "mm");
+	if (IS_ERR(pwm->clk_mm))
+		return PTR_ERR(pwm->clk_mm);
+
+	ret = clk_prepare_enable(pwm->clk_main);
+	if (ret < 0)
+		return ret;
+	ret = clk_prepare_enable(pwm->clk_mm);
+	if (ret < 0) {
+		clk_disable_unprepare(pwm->clk_main);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pwm);
+
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.ops = &mtk_disp_pwm_ops;
+	pwm->chip.base = -1;
+	pwm->chip.npwm = NUM_PWM;
+
+	ret = pwmchip_add(&pwm->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+		return ret;

This error path leaves the clocks enabled.

I forgot this one. I will fix it.

quoted

+	}
+
+	return 0;
+}
+
+static int mtk_disp_pwm_remove(struct platform_device *pdev)
+{
+	struct mtk_disp_pwm_chip *pc = platform_get_drvdata(pdev);
+
+	if (WARN_ON(!pc))
+		return -ENODEV;
+
+	clk_disable_unprepare(pc->clk_main);
+	clk_disable_unprepare(pc->clk_mm);
+
+	return pwmchip_remove(&pc->chip);

You should first remove the pwmchip and disable the clocks afterwards.
Also note that this function can fail.

OK.

Sascha

Thank for your suggestion.

Regards,
YH Huang