From 31e1391af210fdbf177966579a83d14e6a4cd828 Mon Sep 17 00:00:00 2001
From: Daniel Mack <daniel@zonque.org>
Date: Tue, 24 Jul 2018 19:11:26 +0200
Subject: video: fbdev: pxafb: Add support for lcd-supply regulator

Optionally obtain a lcd-supply regulator during probe and use it in
__pxafb_lcd_power() to switch the power supply of LCD panels.

This helps boards booted from DT to control such voltages without
callbacks.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Reviewed-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 drivers/video/fbdev/pxafb.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'drivers/video/fbdev/pxafb.c')

diff --git a/drivers/video/fbdev/pxafb.c b/drivers/video/fbdev/pxafb.c
index 68459b07d442..bbed039617a4 100644
--- a/drivers/video/fbdev/pxafb.c
+++ b/drivers/video/fbdev/pxafb.c
@@ -56,6 +56,7 @@
 #include <linux/freezer.h>
 #include <linux/console.h>
 #include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
 #include <video/of_display_timing.h>
 #include <video/videomode.h>
 
@@ -1423,6 +1424,21 @@ static inline void __pxafb_lcd_power(struct pxafb_info *fbi, int on)
 
 	if (fbi->lcd_power)
 		fbi->lcd_power(on, &fbi->fb.var);
+
+	if (fbi->lcd_supply && fbi->lcd_supply_enabled != on) {
+		int ret;
+
+		if (on)
+			ret = regulator_enable(fbi->lcd_supply);
+		else
+			ret = regulator_disable(fbi->lcd_supply);
+
+		if (ret < 0)
+			pr_warn("Unable to %s LCD supply regulator: %d\n",
+				on ? "enable" : "disable", ret);
+		else
+			fbi->lcd_supply_enabled = on;
+	}
 }
 
 static void pxafb_enable_controller(struct pxafb_info *fbi)
@@ -2299,6 +2315,14 @@ static int pxafb_probe(struct platform_device *dev)
 	fbi->backlight_power = inf->pxafb_backlight_power;
 	fbi->lcd_power = inf->pxafb_lcd_power;
 
+	fbi->lcd_supply = devm_regulator_get_optional(&dev->dev, "lcd");
+	if (IS_ERR(fbi->lcd_supply)) {
+		if (PTR_ERR(fbi->lcd_supply) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		fbi->lcd_supply = NULL;
+	}
+
 	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (r == NULL) {
 		dev_err(&dev->dev, "no I/O memory resource defined\n");
-- 
cgit v1.2.3