Re: Tegra boots failing due to as3722 I/O errors

Jon Hunter
2016-03-30T11:31:56Z

Hi Mark,

On 29/03/16 20:03, Mark Brown wrote:
> * PGP Signed by an unknown key
>
> Hi,
>
> Currently the Jetson TK1 is failing to get regulators for MMC with at
> least my regulator tree and probably -next also due to:
>
> [ 1.665750] as3722 4-0040: AS3722 with revision 0x1 found
> [ 1.682945] +VDDIO_SDMMC3: failed to get the current voltage(-22)
> [ 1.689135] as3722-regulator as3722-regulator: regulator 13 register failed -22
> [ 1.697593] as3722-regulator: probe of as3722-regulator failed with error -22
>
> The get voltage operation here is just a simple mapping of a bitfield in
> the regmap which suggests that the underlying problem is somewhere
> further down the stack like the MFD or I2C drivers. The error is
> -EINVAL which suggests something like the register not being marked as
> readable but the _VOLTAGE_REG registers appear to be marked as readable
> in the MFD.
>
> Full log for one boot at:
>
> https://storage.kernelci.org/broonie-regulator/v4.6-rc1-24-ga7e614dd1f91/arm-multi_v7_defconfig+CONFIG_SMP=n/lab-mhart/boot-tegra124-jetson-tk1.html

Thanks for the report. I took a quick look at this and it turns out
that i2c and regmap are all working fine. The problem is the
VDDIO_SDMMC3 LDO (aka. LDO6) on the as3722 has a bypass mode which is
not represented by the voltage ranges for the LDO. On boot the LDO is
in bypass and returns a value which is not recognised and hence an
EINVAL is returned. The following change fixes the problem. The 0x3F
value represents the bypass mode. I will send out a formal patch.

Cheers
Jon

diff --git a/drivers/regulator/as3722-regulator.c b/drivers/regulator/as3722-regulator.c
index 8b046ee..f16d0e5 100644
--- a/drivers/regulator/as3722-regulator.c
+++ b/drivers/regulator/as3722-regulator.c
@@ -438,6 +438,13 @@ static const struct regulator_linear_range as3722_ldo_ranges[] = {
REGULATOR_LINEAR_RANGE(1725000, 0x40, 0x7F, 25000),
};

+static const struct regulator_linear_range as3722_ldo6_ranges[] = {
+ REGULATOR_LINEAR_RANGE(0, 0x00, 0x00, 0),
+ REGULATOR_LINEAR_RANGE(825000, 0x01, 0x24, 25000),
+ REGULATOR_LINEAR_RANGE(3300000, 0x3F, 0x3F, 0),
+ REGULATOR_LINEAR_RANGE(1725000, 0x40, 0x7F, 25000),
+};
+
static struct regulator_ops as3722_ldo_ops = {
.is_enabled = regulator_is_enabled_regmap,
.enable = regulator_enable_regmap,
@@ -863,6 +870,16 @@ static int as3722_regulator_probe(struct platform_device *pdev)
as3722_regs->desc[id].n_linear_ranges =
ARRAY_SIZE(as3722_sd2345_ranges);
break;
+ case AS3722_REGULATOR_ID_LDO6:
+ if (reg_config->ext_control)
+ ops = &as3722_ldo_extcntrl_ops;
+ else
+ ops = &as3722_ldo_ops;
+ as3722_regs->desc[id].enable_time = 500;
+ as3722_regs->desc[id].linear_ranges = as3722_ldo6_ranges;
+ as3722_regs->desc[id].n_linear_ranges =
+ ARRAY_SIZE(as3722_ldo6_ranges);
+ break;
default:
if (reg_config->ext_control)
ops = &as3722_ldo_extcntrl_ops;