video: fbdev: imxfb: ensure balanced regulator usage (5c694f80) · Commits · 戴 / test

The fbdev framework doesn't care to call the .set_power callback only on changes. So the driver has to care for itself that the regulator doesn't get disabled more often than enabled. This fixes the regulator warning unbalanced disables for lcd supply which can be triggered by doing echo 4 > /sys/class/lcd/imxfb-lcd/lcd_power twice. Signed-off-by:

Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Signed-off-by:

Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200323211626.24812-1-u.kleine-koenig@pengutronix.de

drivers/video/fbdev/imxfb.c

+21 −6

Original line number	Diff line number	Diff line
		@@ -172,6 +172,7 @@ struct imxfb_info {
		int num_modes;

		struct regulator *lcd_pwr;
		int lcd_pwr_enabled;
		};

		static const struct platform_device_id imxfb_devtype[] = {
		@@ -801,17 +802,31 @@ static int imxfb_lcd_get_power(struct lcd_device *lcddev)
		return FB_BLANK_UNBLANK;
		}

		static int imxfb_lcd_set_power(struct lcd_device *lcddev, int power)
		static int imxfb_regulator_set(struct imxfb_info *fbi, int enable)
		{
		struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
		int ret;

		if (!IS_ERR(fbi->lcd_pwr)) {
		if (power == FB_BLANK_UNBLANK)
		return regulator_enable(fbi->lcd_pwr);
		if (enable == fbi->lcd_pwr_enabled)
		return 0;

		if (enable)
		ret = regulator_enable(fbi->lcd_pwr);
		else
		return regulator_disable(fbi->lcd_pwr);
		ret = regulator_disable(fbi->lcd_pwr);

		if (ret == 0)
		fbi->lcd_pwr_enabled = enable;

		return ret;
		}

		static int imxfb_lcd_set_power(struct lcd_device *lcddev, int power)
		{
		struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);

		if (!IS_ERR(fbi->lcd_pwr))
		return imxfb_regulator_set(fbi, power == FB_BLANK_UNBLANK);

		return 0;
		}

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