[PATCH] regulator: axp20x: Fix axp809 ldo_io registration error on cold boot

[PATCH] regulator: axp20x: Fix axp809 ldo_io registration error on cold boot

[Chen-Yu Tsai]

The maximum supported voltage for ldo_io# is 3.3V, but on cold boot
the selector comes up at 0x1f, which maps to 3.8V. This was previously
corrected by Allwinner's U-boot, which set all regulators on the PMICs
to some pre-configured voltage. With recent progress in U-boot SPL
support, this is no longer the case. In any case we should handle
this quirk in the kernel driver as well.

This invalid setting causes _regulator_get_voltage() to fail with -EINVAL
which causes regulator registration to fail when constrains are used:

[    1.054181] vcc-pg: failed to get the current voltage(-22)
[    1.059670] axp20x-regulator axp20x-regulator.0: Failed to register ldo_io0
[    1.069749] axp20x-regulator: probe of axp20x-regulator.0 failed with error -22

This commits makes the axp20x regulator driver accept the 0x1f register
value, fixing this.

The datasheet does not guarantee reliable operation above 3.3V, so on
boards where this regulator is used the regulator-max-microvolt setting
must be 3.3V or less.

This is essentially the same as the commit f40d4896bf32 ("regulator:
axp20x: Fix axp22x ldo_io registration error on cold boot") for AXP22x
PMICs.

Fixes: a51f9f4622a3 ("regulator: axp20x: support AXP809 variant")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 drivers/regulator/axp20x-regulator.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
index 54382ef902c6..e6a512ebeae2 100644
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -337,10 +337,18 @@ static const struct regulator_desc axp809_regulators[] = {
 		 AXP22X_ELDO2_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(1)),
 	AXP_DESC(AXP809, ELDO3, "eldo3", "eldoin", 700, 3300, 100,
 		 AXP22X_ELDO3_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(2)),
-	AXP_DESC_IO(AXP809, LDO_IO0, "ldo_io0", "ips", 700, 3300, 100,
+	/*
+	 * Note the datasheet only guarantees reliable operation up to
+	 * 3.3V, this needs to be enforced via dts provided constraints
+	 */
+	AXP_DESC_IO(AXP809, LDO_IO0, "ldo_io0", "ips", 700, 3800, 100,
 		    AXP22X_LDO_IO0_V_OUT, 0x1f, AXP20X_GPIO0_CTRL, 0x07,
 		    AXP22X_IO_ENABLED, AXP22X_IO_DISABLED),
-	AXP_DESC_IO(AXP809, LDO_IO1, "ldo_io1", "ips", 700, 3300, 100,
+	/*
+	 * Note the datasheet only guarantees reliable operation up to
+	 * 3.3V, this needs to be enforced via dts provided constraints
+	 */
+	AXP_DESC_IO(AXP809, LDO_IO1, "ldo_io1", "ips", 700, 3800, 100,
 		    AXP22X_LDO_IO1_V_OUT, 0x1f, AXP20X_GPIO1_CTRL, 0x07,
 		    AXP22X_IO_ENABLED, AXP22X_IO_DISABLED),
 	AXP_DESC_FIXED(AXP809, RTC_LDO, "rtc_ldo", "ips", 1800),
-- 
2.10.2

Applied "regulator: axp20x: Fix axp809 ldo_io registration error on cold boot" to the regulator tree

[Mark Brown]

The patch

   regulator: axp20x: Fix axp809 ldo_io registration error on cold boot

has been applied to the regulator tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 618c808968852609d2d9f0e5cfc351a4807ef8d0 Mon Sep 17 00:00:00 2001
From: Chen-Yu Tsai <wens@csie.org>
Date: Fri, 11 Nov 2016 11:12:43 +0800
Subject: [PATCH] regulator: axp20x: Fix axp809 ldo_io registration error on
 cold boot

The maximum supported voltage for ldo_io# is 3.3V, but on cold boot
the selector comes up at 0x1f, which maps to 3.8V. This was previously
corrected by Allwinner's U-boot, which set all regulators on the PMICs
to some pre-configured voltage. With recent progress in U-boot SPL
support, this is no longer the case. In any case we should handle
this quirk in the kernel driver as well.

This invalid setting causes _regulator_get_voltage() to fail with -EINVAL
which causes regulator registration to fail when constrains are used:

[    1.054181] vcc-pg: failed to get the current voltage(-22)
[    1.059670] axp20x-regulator axp20x-regulator.0: Failed to register ldo_io0
[    1.069749] axp20x-regulator: probe of axp20x-regulator.0 failed with error -22

This commits makes the axp20x regulator driver accept the 0x1f register
value, fixing this.

The datasheet does not guarantee reliable operation above 3.3V, so on
boards where this regulator is used the regulator-max-microvolt setting
must be 3.3V or less.

This is essentially the same as the commit f40d4896bf32 ("regulator:
axp20x: Fix axp22x ldo_io registration error on cold boot") for AXP22x
PMICs.

Fixes: a51f9f4622a3 ("regulator: axp20x: support AXP809 variant")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/regulator/axp20x-regulator.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
index 54382ef902c6..e6a512ebeae2 100644
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -337,10 +337,18 @@ static const struct regulator_desc axp809_regulators[] = {
 		 AXP22X_ELDO2_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(1)),
 	AXP_DESC(AXP809, ELDO3, "eldo3", "eldoin", 700, 3300, 100,
 		 AXP22X_ELDO3_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(2)),
-	AXP_DESC_IO(AXP809, LDO_IO0, "ldo_io0", "ips", 700, 3300, 100,
+	/*
+	 * Note the datasheet only guarantees reliable operation up to
+	 * 3.3V, this needs to be enforced via dts provided constraints
+	 */
+	AXP_DESC_IO(AXP809, LDO_IO0, "ldo_io0", "ips", 700, 3800, 100,
 		    AXP22X_LDO_IO0_V_OUT, 0x1f, AXP20X_GPIO0_CTRL, 0x07,
 		    AXP22X_IO_ENABLED, AXP22X_IO_DISABLED),
-	AXP_DESC_IO(AXP809, LDO_IO1, "ldo_io1", "ips", 700, 3300, 100,
+	/*
+	 * Note the datasheet only guarantees reliable operation up to
+	 * 3.3V, this needs to be enforced via dts provided constraints
+	 */
+	AXP_DESC_IO(AXP809, LDO_IO1, "ldo_io1", "ips", 700, 3800, 100,
 		    AXP22X_LDO_IO1_V_OUT, 0x1f, AXP20X_GPIO1_CTRL, 0x07,
 		    AXP22X_IO_ENABLED, AXP22X_IO_DISABLED),
 	AXP_DESC_FIXED(AXP809, RTC_LDO, "rtc_ldo", "ips", 1800),
-- 
2.10.2