Re: [PATCH v3 2/4] mfd: pm8xxx-spmi: document DT bindings for Qualcomm SPMI PMICs

David Collins
2014-07-29T22:23:35Z

On 07/24/2014 05:45 AM, Stanimir Varbanov wrote:
> Document DT bindings used to describe the Qualcomm SPMI PMICs.
> Currently the SPMI PMICs supported are pm8941, pm8841 and pma8084.
>
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>

(...)
> +Required properties for peripheral child nodes:
> +- compatible: Should contain "qcom,pm8xxx-xxx", where "xxx" is
> + peripheral name. The "pm8xxx" can be any of supported PMICs,
> + see example below.

I don't think that this binding document should be imposing any formatting
restrictions on the compatible strings for QPNP peripheral drivers. The
QPNP peripheral drivers in the downstream msm-3.10 tree [1] do not specify
per-PMIC compatible strings. This is because ideally, a given QPNP
peripheral represents a hardware block that is identical in interface and
operation between PMICs.

These peripheral drivers determine the base address for a given device
instance via device tree reg and reg-names properties. In order for this
to continue to work with the pm8xxx-spmi driver, some mechanism will need
to be introduced which creates resource structs for the
non-memory-mappable SPMI base addresses. One possible solution is
currently being discussed in another thread [2]. This document will need
to be updated to show the child node reg property scheme once a solution
is reached.

(...)
> +Example:
> +
> + pm8941@0 {
> + compatible = "qcom,pm8941";
> + reg = <0x0 SPMI_USID>;
> +
> + rtc {
> + compatible = "qcom,pm8941-rtc";
> + interrupts = <0x0 0x61 0x1 IRQ_TYPE_EDGE_RISING>;
> + interrupt-names = "alarm";
> + };
> + };

Can you please expand your example to include the second SID for the
PM8941 chip? That way, it will be clear that each PMIC needs two DT
nodes; one for each SID.

Thanks,
David Collins

[1]: https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.10/tree/?h=msm-3.10

[2]: https://lkml.org/lkml/2014/7/29/252

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