From d8bc92af0a6045abb75f968a13ea5491a23a3040 Mon Sep 17 00:00:00 2001
From: Caesar Wang <wxt@rock-chips.com>
Date: Thu, 14 Feb 2019 10:01:12 +0800
Subject: [PATCH] regulator: core: Fix device link error when registering
 regulator

The sysfs device link can only be created after regulator device
registered.

Otherwise, the regulator always have some warning logs.
...
[    1.033024] DCDC_REG1: supplied by vcc5v0_sys
[    1.033427] vcc5v0_sys: could not add device link regulator.3 err -2
[    1.034302] vdd_center: 750 <--> 1350 mV at 900 mV
[    1.034862] rk808 0-0020: Looking up vcc2-supply from device tree
[    1.034907] DCDC_REG2: supplied by vcc5v0_sys
[    1.035298] vcc5v0_sys: could not add device link regulator.4 err -2
[    1.036301] vdd_cpu_l: 750 <--> 1350 mV at 900 mV
[    1.036837] rk808 0-0020: Looking up vcc3-supply from device tree
[    1.036880] DCDC_REG3: supplied by vcc5v0_sys
[    1.037271] vcc5v0_sys: could not add device link regulator.5 err -2
[    1.037985] vcc_ddr: at 500 mV
[    1.038508] rk808 0-0020: Looking up vcc4-supply from device tree
[    1.038550] DCDC_REG4: supplied by vcc5v0_sys
[    1.038941] vcc5v0_sys: could not add device link regulator.6 err -2
[    1.039657] vcc3v3_sys: 3300 mV
[    1.040179] rk808 0-0020: Looking up vcc9-supply from device tree
[    1.040223] DCDC_REG5: supplied by vcc5v0_sys

Fixes: c438b9d017362 ("regulator: core: Move registration of regulator device")

Change-Id: Ie20421eab45f3f8229a5bedf3fecf99c757160bb
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
---
 drivers/regulator/core.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a93c76762c23..389dadd89fda 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1337,12 +1337,15 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 		if (regulator->supply_name == NULL)
 			goto overflow_err;
 
-		err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj,
-					buf);
-		if (err) {
-			rdev_dbg(rdev, "could not add device link %s err %d\n",
-				  dev->kobj.name, err);
-			/* non-fatal */
+		if (device_is_registered(dev)) {
+			err = sysfs_create_link_nowarn(&rdev->dev.kobj,
+						       &dev->kobj, buf);
+			if (err) {
+				rdev_dbg(rdev,
+					 "could not add device link %s err %d\n",
+					 dev->kobj.name, err);
+				/* non-fatal */
+			}
 		}
 	} else {
 		regulator->supply_name = kstrdup(supply_name, GFP_KERNEL);
@@ -4411,6 +4414,19 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	}
 
 	dev_set_drvdata(&rdev->dev, rdev);
+
+	/* Add a link to the device sysfs entry */
+	if (rdev->supply && rdev->supply->dev) {
+		ret = sysfs_create_link_nowarn(&rdev->supply->dev->kobj,
+					       &rdev->dev.kobj,
+					       rdev->supply->supply_name);
+		if (ret) {
+			rdev_dbg(rdev, "could not add device link %s err %d\n",
+				 rdev->dev.kobj.name, ret);
+			/* non-fatal */
+		}
+	}
+
 	rdev_init_debugfs(rdev);
 	rdev_init_early_min_volt(rdev);