[PATCH 1/3] iio: adc: mt6359-auxadc: correct channel types to IIO_VOLTAGE
Jonathan Cameron
jic23 at kernel.org
Tue Nov 3 15:42:37 PST 2026
On Tue, 03 Nov 2026 18:32:07 +0200
Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com at kernel.org> wrote:
> From: Roman Vivchar <rva333 at protonmail.com>
>
> All mt6357, mt6358, mt6359 and mt6363 declare their channel types as
> voltage, resistance and temperature. This is wrong, since the PMIC
> doesn't include any built-in conversion block. It simply measures
> voltage, while consumers are supposed to convert these readings to
> the actual temperature or resistance using efuse calibration.
Hi Roman,
Useful to have an example of the consumer that is doing this.
>
> Correct all channel types to IIO_VOLTAGE.
>
> Fixes: 3587914bf61d ("iio: adc: Add support for MediaTek MT6357/8/9 Auxiliary ADC")
> Fixes: d6f49313272b ("iio: adc: mt6359: Add support for MediaTek MT6363 PMIC AUXADC")
> Signed-off-by: Roman Vivchar <rva333 at protonmail.com>
This one makes me very nervous, not because it is wrong but rather
because there may be a bunch of userspace relying on these wrong
channel types.
It is horrible but I think we can't touch that :( What we can do is
put the right interface in place as well. Thankfully it looks like
the channel index is independent of the channel type so we can duplicate
the wrong channels with voltage ones + some comments to make sure this
doesn't propagate to any new supported devices.
AngeloGioacchino, why did you go with the different channel types?
If we do decide to go ahead with this approach, are there other channels
that are validly using the channel type for non voltage? If not change
the macro to drop the parameter.
Thanks,
Jonathan
> ---
> drivers/iio/adc/mt6359-auxadc.c | 78 ++++++++++++++++++++---------------------
> 1 file changed, 39 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/iio/adc/mt6359-auxadc.c b/drivers/iio/adc/mt6359-auxadc.c
> index 88b0e26309e5..951d236f972b 100644
> --- a/drivers/iio/adc/mt6359-auxadc.c
> +++ b/drivers/iio/adc/mt6359-auxadc.c
> @@ -205,18 +205,18 @@ struct mtk_pmic_auxadc_info {
> }
>
> static const struct iio_chan_spec mt6357_auxadc_channels[] = {
> - MTK_PMIC_IIO_CHAN(MT6357, bat_adc, BATADC, 0, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6357, isense, ISENSE, 1, 12, IIO_CURRENT),
> - MTK_PMIC_IIO_CHAN(MT6357, cdt_v, VCDT, 2, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, batt_temp, BAT_TEMP, 3, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, chip_temp, CHIP_TEMP, 4, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, acc_det, ACCDET, 5, 12, IIO_RESISTANCE),
> + MTK_PMIC_IIO_CHAN(MT6357, bat_adc, BATADC, 0, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, isense, ISENSE, 1, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, cdt_v, VCDT, 2, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, batt_temp, BAT_TEMP, 3, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, chip_temp, CHIP_TEMP, 4, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, acc_det, ACCDET, 5, 12, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6357, dcxo_v, VDCXO, 6, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6357, tsx_temp, TSX_TEMP, 7, 15, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6357, dcxo_temp, DCXO_TEMP, 36, 15, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, vcore_temp, VCORE_TEMP, 40, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6357, vproc_temp, VPROC_TEMP, 41, 12, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6357, tsx_temp, TSX_TEMP, 7, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, dcxo_temp, DCXO_TEMP, 36, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, vcore_temp, VCORE_TEMP, 40, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6357, vproc_temp, VPROC_TEMP, 41, 12, IIO_VOLTAGE),
If this is all of the channels (I haven't checked) you should drop
the ability to configure the channel type from the macro...
However, see discussion at the top.
>
> /* Battery impedance channels */
> MTK_PMIC_IIO_CHAN(MT6357, batt_v, VBAT, 0, 15, IIO_VOLTAGE),
> @@ -251,19 +251,19 @@ static const u16 mt6357_auxadc_regs[] = {
> };
>
> static const struct iio_chan_spec mt6358_auxadc_channels[] = {
> - MTK_PMIC_IIO_CHAN(MT6358, bat_adc, BATADC, 0, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6358, cdt_v, VCDT, 2, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, batt_temp, BAT_TEMP, 3, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, chip_temp, CHIP_TEMP, 4, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, acc_det, ACCDET, 5, 12, IIO_RESISTANCE),
> + MTK_PMIC_IIO_CHAN(MT6358, bat_adc, BATADC, 0, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, cdt_v, VCDT, 2, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, batt_temp, BAT_TEMP, 3, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, chip_temp, CHIP_TEMP, 4, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, acc_det, ACCDET, 5, 12, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6358, dcxo_v, VDCXO, 6, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6358, tsx_temp, TSX_TEMP, 7, 15, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6358, dcxo_temp, DCXO_TEMP, 10, 15, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6358, tsx_temp, TSX_TEMP, 7, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, dcxo_temp, DCXO_TEMP, 10, 15, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6358, bif_v, VBIF, 11, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6358, vcore_temp, VCORE_TEMP, 38, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, vproc_temp, VPROC_TEMP, 39, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6358, vgpu_temp, VGPU_TEMP, 40, 12, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6358, vcore_temp, VCORE_TEMP, 38, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, vproc_temp, VPROC_TEMP, 39, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6358, vgpu_temp, VGPU_TEMP, 40, 12, IIO_VOLTAGE),
>
> /* Battery impedance channels */
> MTK_PMIC_IIO_CHAN(MT6358, batt_v, VBAT, 0, 15, IIO_VOLTAGE),
> @@ -299,18 +299,18 @@ static const u16 mt6358_auxadc_regs[] = {
> };
>
> static const struct iio_chan_spec mt6359_auxadc_channels[] = {
> - MTK_PMIC_IIO_CHAN(MT6359, bat_adc, BATADC, 0, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6359, batt_temp, BAT_TEMP, 3, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6359, chip_temp, CHIP_TEMP, 4, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6359, acc_det, ACCDET, 5, 12, IIO_RESISTANCE),
> + MTK_PMIC_IIO_CHAN(MT6359, bat_adc, BATADC, 0, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, batt_temp, BAT_TEMP, 3, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, chip_temp, CHIP_TEMP, 4, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, acc_det, ACCDET, 5, 12, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6359, dcxo_v, VDCXO, 6, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6359, tsx_temp, TSX_TEMP, 7, 15, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6359, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6359, dcxo_temp, DCXO_TEMP, 10, 15, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6359, tsx_temp, TSX_TEMP, 7, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, hp_ofs_cal, HPOFS_CAL, 9, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, dcxo_temp, DCXO_TEMP, 10, 15, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6359, bif_v, VBIF, 11, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6359, vcore_temp, VCORE_TEMP, 30, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6359, vproc_temp, VPROC_TEMP, 31, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6359, vgpu_temp, VGPU_TEMP, 32, 12, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6359, vcore_temp, VCORE_TEMP, 30, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, vproc_temp, VPROC_TEMP, 31, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6359, vgpu_temp, VGPU_TEMP, 32, 12, IIO_VOLTAGE),
>
> /* Battery impedance channels */
> MTK_PMIC_IIO_CHAN(MT6359, batt_v, VBAT, 0, 15, IIO_VOLTAGE),
> @@ -349,15 +349,15 @@ static const u16 mt6359_auxadc_regs[] = {
> };
>
> static const struct iio_chan_spec mt6363_auxadc_channels[] = {
> - MTK_PMIC_IIO_CHAN(MT6363, bat_adc, BATADC, 0, 15, IIO_RESISTANCE),
> - MTK_PMIC_IIO_CHAN(MT6363, cdt_v, VCDT, 2, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6363, batt_temp, BAT_TEMP, 3, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6363, chip_temp, CHIP_TEMP, 4, 12, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6363, bat_adc, BATADC, 0, 15, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6363, cdt_v, VCDT, 2, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6363, batt_temp, BAT_TEMP, 3, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6363, chip_temp, CHIP_TEMP, 4, 12, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6363, sys_sns_v, VSYSSNS, 6, 15, IIO_VOLTAGE),
> MTK_PMIC_IIO_CHAN(MT6363, tref_v, VTREF, 11, 12, IIO_VOLTAGE),
> - MTK_PMIC_IIO_CHAN(MT6363, vcore_temp, VCORE_TEMP, 38, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6363, vproc_temp, VPROC_TEMP, 39, 12, IIO_TEMP),
> - MTK_PMIC_IIO_CHAN(MT6363, vgpu_temp, VGPU_TEMP, 40, 12, IIO_TEMP),
> + MTK_PMIC_IIO_CHAN(MT6363, vcore_temp, VCORE_TEMP, 38, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6363, vproc_temp, VPROC_TEMP, 39, 12, IIO_VOLTAGE),
> + MTK_PMIC_IIO_CHAN(MT6363, vgpu_temp, VGPU_TEMP, 40, 12, IIO_VOLTAGE),
>
> /* For VIN, ADC12 holds the result depending on which GPIO was activated */
> MTK_PMIC_IIO_CHAN(MT6363, in1_v, VIN1, 45, 15, IIO_VOLTAGE),
>
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