Re: [PATCH 1/2] mfd: pm8x41: add support for Qualcomm 8x41 PMICs

[Rob Herring <robherring2@gmail.com>]

On Wed, Apr 23, 2014 at 8:19 AM, Ivan T. Ivanov <iivanov@mm-sol.com> wrote:
>
> Hi,
>
> On Tue, 2014-04-22 at 17:31 -0700, Courtney Cavin wrote:
>> From: Josh Cartwright <joshc@codeaurora.org>
>>
>> The Qualcomm 8941 and 8841 PMICs are components used with the Snapdragon
>> 800 series SoC family.  This driver exists largely as a glue mfd component,
>> it exists to be an owner of an SPMI regmap for children devices
>> described in device tree.
>>
>
> Thanks. This is exactly what I have planed to do :-)
>
>> Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
>> Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
>> ---
>>  drivers/mfd/Kconfig  | 13 +++++++++++
>>  drivers/mfd/Makefile |  1 +
>>  drivers/mfd/pm8x41.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 77 insertions(+)
>>  create mode 100644 drivers/mfd/pm8x41.c
>>
>
> <snip>
>
>> +
>> +static int pm8x41_probe(struct spmi_device *sdev)
>> +{
>> +     struct regmap *regmap;
>> +
>> +     regmap = devm_regmap_init_spmi_ext(sdev, &pm8x41_regmap_config);
>> +     if (IS_ERR(regmap)) {
>> +             dev_dbg(&sdev->dev, "regmap creation failed.\n");
>> +             return PTR_ERR(regmap);
>> +     }
>> +
>> +     return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
>
> I think that this will not going to work. For example in this particular
> case, both controllers have "qcom,qpnp-revid" peripheral which is
> located at offset 0x100.
>
> And the result is:
>
> [    0.963944] sysfs: cannot create duplicate filename '/bus/platform/devices/100.revid'
>
> DT looks like this:
>
> spmi {
>         compatible = "qcom,spmi-pmic-arb";
>         reg-names = "core", "intr", "cnfg";
>         reg = <0xfc4cf000 0x1000>,
>               <0xfc4cb000 0x1000>,
>               <0xfc4ca000 0x1000>;
>
>         interrupt-names = "periph_irq";
>         interrupts = <0 190 0>;
>
>         qcom,ee = <0>;
>         qcom,channel = <0>;
>
>         #address-cells = <2>;
>         #size-cells = <0>;
>
>         interrupt-controller;
>         #interrupt-cells = <4>;
>
>         pm8941@0 {
>                 compatible = "qcom,pm8941";
>                 reg = <0x0 SPMI_USID>;
>
>                 #address-cells = <1>;
>                 #size-cells = <0>;
>
>                 revid@100 {
>                         compatible = "qcom,qpnp-revid";
>                         reg = <0x100 0x100>;
>                 };
>         };
>
>         pm8841@4 {
>                 compatible = "qcom,pm8941";
>                 reg = <0x4 SPMI_USID>;
>
>                 #address-cells = <1>;
>                 #size-cells = <0>;
>
>                 revid@100 {
>                         compatible = "qcom,qpnp-revid";
>                         reg = <0x100 0x100>;
>                 };
>         };
> };
>
> Any suggestions?

Probably we should only use the unit address when we have translatable
addresses. Or we could append the parent reg address to the name, but
you may have cases that don't have a parent reg value.

Rob