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

[David Collins <collinsd@codeaurora.org>]

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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