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authorBastian Stender <bst@pengutronix.de>2017-04-07 17:28:23 +0200
committerBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2017-04-07 17:28:23 +0200
commitcfc5b2b551d8c089079e754525839101b1b43624 (patch)
tree62ae70745e3b6d6132da4c46ecf1c49829ac62f8 /drivers/video
parentc1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff)
downloadlinux-cfc5b2b551d8c089079e754525839101b1b43624.tar.gz
fbdev/ssd1307fb: fix optional VBAT support
SSD1306 needs VBAT when it is wired in charge pump configuration only.
Other controllers of the SSD1307 family do not need it at all. This was
introduced by commit ba14301e0356 ("fbdev/ssd1307fb: add support to
enable VBAT").

Without VBAT configuration the driver now fails with:

	failed to get VBAT regulator: -19

This is caused by misinterpretation of devm_regulator_get_optional
which "returns a struct regulator corresponding to the regulator
producer or IS_ERR() condition".

Handle -ENODEV without bailing out and making VBAT support really
optional.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Roger Quadros <rogerq@ti.com>
[b.zolnierkie: minor fixups]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fbdev/ssd1307fb.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index bd017b57c47f..f599520374dd 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -578,10 +578,14 @@ static int ssd1307fb_probe(struct i2c_client *client,
 
 	par->vbat_reg = devm_regulator_get_optional(&client->dev, "vbat");
 	if (IS_ERR(par->vbat_reg)) {
-		dev_err(&client->dev, "failed to get VBAT regulator: %ld\n",
-			PTR_ERR(par->vbat_reg));
 		ret = PTR_ERR(par->vbat_reg);
-		goto fb_alloc_error;
+		if (ret == -ENODEV) {
+			par->vbat_reg = NULL;
+		} else {
+			dev_err(&client->dev, "failed to get VBAT regulator: %d\n",
+				ret);
+			goto fb_alloc_error;
+		}
 	}
 
 	if (of_property_read_u32(node, "solomon,width", &par->width))
@@ -668,10 +672,13 @@ static int ssd1307fb_probe(struct i2c_client *client,
 		udelay(4);
 	}
 
-	ret = regulator_enable(par->vbat_reg);
-	if (ret) {
-		dev_err(&client->dev, "failed to enable VBAT: %d\n", ret);
-		goto reset_oled_error;
+	if (par->vbat_reg) {
+		ret = regulator_enable(par->vbat_reg);
+		if (ret) {
+			dev_err(&client->dev, "failed to enable VBAT: %d\n",
+				ret);
+			goto reset_oled_error;
+		}
 	}
 
 	ret = ssd1307fb_init(par);
@@ -710,7 +717,8 @@ panel_init_error:
 		pwm_put(par->pwm);
 	};
 regulator_enable_error:
-	regulator_disable(par->vbat_reg);
+	if (par->vbat_reg)
+		regulator_disable(par->vbat_reg);
 reset_oled_error:
 	fb_deferred_io_cleanup(info);
 fb_alloc_error: