[PATCH v3] regulator: axp20x: Fix axp22x ldo_io registration error on cold boot

[PATCH v3] regulator: axp20x: Fix axp22x ldo_io registration error on cold boot

[Hans de Goede]

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

[    1.467788] vcc-touchscreen: failed to get the current voltage(-22)
[    1.474209] axp20x-regulator axp20x-regulator: Failed to register ldo_io1
[    1.483363] axp20x-regulator: probe of axp20x-regulator 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.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-No changes (resend)
Changes in v3:
-Instead of overwriting the 0x1f register value even when the regulator
 is not used / not described in dt, accept 0x1f as a valid value and
 when the regulator is used rely on the constraints to ensure that
 a value in the supported output range gets used.
---
 drivers/regulator/axp20x-regulator.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
index d0f8d10..2422ddd 100644
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -219,10 +219,14 @@ static const struct regulator_desc axp22x_regulators[] = {
 		 AXP22X_ELDO2_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(1)),
 	AXP_DESC(AXP22X, ELDO3, "eldo3", "eldoin", 700, 3300, 100,
 		 AXP22X_ELDO3_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(2)),
-	AXP_DESC_IO(AXP22X, 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(AXP22X, 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(AXP22X, 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(AXP22X, 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(AXP22X, RTC_LDO, "rtc_ldo", "ips", 3000),
-- 
2.7.4

Applied "regulator: axp20x: Fix axp22x ldo_io registration error on cold boot" to the regulator tree

[Mark Brown]

The patch

   regulator: axp20x: Fix axp22x 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 f40d4896bf3284573f1e70e8840c1bcfe1c6bf2d Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Wed, 27 Apr 2016 20:38:44 +0200
Subject: [PATCH] regulator: axp20x: Fix axp22x 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 causes _regulator_get_voltage() to fail with -EINVAL which
causes regulator registration to fail when constrains are used:

[    1.467788] vcc-touchscreen: failed to get the current voltage(-22)
[    1.474209] axp20x-regulator axp20x-regulator: Failed to register ldo_io1
[    1.483363] axp20x-regulator: probe of axp20x-regulator 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.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/regulator/axp20x-regulator.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
index 89f684295657..514a5e8fdbab 100644
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -217,10 +217,14 @@ static const struct regulator_desc axp22x_regulators[] = {
 		 AXP22X_ELDO2_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(1)),
 	AXP_DESC(AXP22X, ELDO3, "eldo3", "eldoin", 700, 3300, 100,
 		 AXP22X_ELDO3_V_OUT, 0x1f, AXP22X_PWR_OUT_CTRL2, BIT(2)),
-	AXP_DESC_IO(AXP22X, 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(AXP22X, 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(AXP22X, 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(AXP22X, 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(AXP22X, RTC_LDO, "rtc_ldo", "ips", 3000),
-- 
2.8.0.rc3