[PATCH 3.16 007/114] regulator: s2mps11: Fix invalid selector mask and voltages for buck9

[Ben Hutchings]

3.16.36-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>

commit 3b672623079bb3e5685b8549e514f2dfaa564406 upstream.

The buck9 regulator of S2MPS11 PMIC had incorrect vsel_mask (0xff
instead of 0x1f) thus reading entire register as buck9's voltage. This
effectively caused regulator core to interpret values as higher voltages
than they were and then to set real voltage much lower than intended.

The buck9 provides power to other regulators, including LDO13
and LDO19 which supply the MMC2 (SD card). On Odroid XU3/XU4 the lower
voltage caused SD card detection errors on Odroid XU3/XU4:
	mmc1: card never left busy state
	mmc1: error -110 whilst initialising SD card

During driver probe the regulator core was checking whether initial
voltage matches the constraints. With incorrect vsel_mask of 0xff and
default value of 0x50, the core interpreted this as 5 V which is outside
of constraints (3-3.775 V). Then the regulator core was adjusting the
voltage to match the constraints. With incorrect vsel_mask this new
voltage mapped to a vere low voltage in the driver.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
Tested-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
[bwh: Backported to 3.16: s2mps11_buck9_ops was never combined with other
 macros here, so just change the n_voltages and vsel_mask fields]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/regulator/s2mps11.c
+++ b/drivers/regulator/s2mps11.c
@@ -335,10 +335,10 @@ static struct regulator_ops s2mps11_buck
 	.owner		= THIS_MODULE,				\
 	.min_uV		= S2MPS11_BUCK_MIN3,			\
 	.uV_step	= S2MPS11_BUCK_STEP3,			\
-	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.n_voltages	= S2MPS11_BUCK9_N_VOLTAGES,		\
 	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B9CTRL2,			\
-	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
+	.vsel_mask	= S2MPS11_BUCK9_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B9CTRL1,			\
 	.enable_mask	= S2MPS11_ENABLE_MASK			\
 }
--- a/include/linux/mfd/samsung/s2mps11.h
+++ b/include/linux/mfd/samsung/s2mps11.h
@@ -182,10 +182,12 @@ enum s2mps11_regulators {
 #define S2MPS11_LDO_STEP2	25000
 #define S2MPS11_LDO_VSEL_MASK	0x3F
 #define S2MPS11_BUCK_VSEL_MASK	0xFF
+#define S2MPS11_BUCK9_VSEL_MASK	0x1F
 #define S2MPS11_ENABLE_MASK	(0x03 << S2MPS11_ENABLE_SHIFT)
 #define S2MPS11_ENABLE_SHIFT	0x06
 #define S2MPS11_LDO_N_VOLTAGES	(S2MPS11_LDO_VSEL_MASK + 1)
 #define S2MPS11_BUCK_N_VOLTAGES (S2MPS11_BUCK_VSEL_MASK + 1)
+#define S2MPS11_BUCK9_N_VOLTAGES (S2MPS11_BUCK9_VSEL_MASK + 1)
 #define S2MPS11_RAMP_DELAY	25000		/* uV/us */