Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <431faa87-d152-5f7a-40fd-8b6fe26f0bb9@linaro.org>
Date:   Tue, 11 Jul 2023 07:58:55 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH 1/7] dt-bindings: soc: qcom: Add qcom-pbs bindings
Content-Language: en-US
To:     Anjelique Melendez <quic_amelende@quicinc.com>,
        Rob Herring <robh@kernel.org>
Cc:     pavel@ucw.cz, lee@kernel.org, thierry.reding@gmail.com,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org,
        u.kleine-koenig@pengutronix.de, linux-leds@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-pwm@vger.kernel.org
References: <20230621185949.2068-1-quic_amelende@quicinc.com>
 <20230621185949.2068-2-quic_amelende@quicinc.com>
 <20230626135857.GA3118929-robh@kernel.org>
 <2e871e21-a81d-0d7d-993b-9a9d7bd9d962@quicinc.com>
 <e7298704-5a03-0961-90a3-dab4af60c326@linaro.org>
 <32e9a512-fd74-b2f6-6b8a-fefb9ad5912d@quicinc.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <32e9a512-fd74-b2f6-6b8a-fefb9ad5912d@quicinc.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 11/07/2023 05:52, Anjelique Melendez wrote:
> 
> 
> On 7/1/2023 4:03 AM, Krzysztof Kozlowski wrote:
>> On 29/06/2023 03:19, Anjelique Melendez wrote:
>>
>>>>> +examples:
>>>>> +  - |
>>>>> +    pmic {
>>>>> +      #address-cells = <1>;
>>>>> +      #size-cells = <0>;
>>>>> +
>>>>> +      qcom,pbs@7400 {
>>>>> +        compatible = "qcom,pbs";
>>>>> +        reg = <0x7400>;
>>>>> +      };
>>>>
>>>> Why do you need a child node for this? Is there more than 1 instance in 
>>>> a PMIC? Every sub-function of a PMIC doesn't have to have a DT node.
>>>>
>>>
>>> We currently have another downstream driver (which is planned to get upstreamed)
>>> which also needs a handle to a pbs device in order to properly trigger events. 
>>
>> I don't see how does it answer Rob's concerns. Neither mine about
>> incomplete binding. You don't need pbs node here for that.
>>
>> Anyway, whatever you have downstream also does not justify any changes.
>> Either upstream these so we can see it or drop this binding.
>>
>> Best regards,
>> Krzysztof
>>
> 
> On PMI632, peripherals are partitioned over 2 different SIDs
> (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/qcom/pmi632.dtsi?h=v6.5-rc1#n42
> and https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/qcom/pmi632.dtsi?h=v6.5-rc1#n149).
> Unfortunately, the pbs peripheral and the lpg peripherals are on different
> PMI632 devices and therefore have different regmaps.
>  
> If we get rid of the pbs node we need to get a handle to the proper regmap.
> I see two possible options, we could either introduce a new client property
> which points to a peripheral on the same device as pbs.
> 
> i.e.
> 	led-controller {
> 		compatible = "qcom,pmi632-lpg";
>       		#address-cells = <1>;
>       		#size-cells = <0>;
>       		#pwm-cells = <2>;
>      		nvmem-names = "lpg_chan_sdam";
>       		nvmem = <&pmi632_sdam7>;
>       		qcom,pbs-phandle = <&pmi632_gpios>;
>       		..... 
> 	};
> Then when client is probing could do something like the following to get the regmap
> 
> 	dn = of_parse_phandle(node, "qcom,pbs-phandle", 0);
> 	pdev = of_find_device_by_node(dn);
> 	pbs_regmap = dev_get_regmap(&pdev->dev->parent, NULL);
> 
> 
> 
> Or we could use the nvmem phandle and just have something like this in client's probe
> 
> 	dn = of_parse_phandle(node, "nvmem", 0);
> 	pdev = of_find_device_by_node(dn);
> 	pbs_regmap = dev_get_regmap(&pdev->dev->parent, NULL);
> 
> 
> 
> Let me know what your thoughts are on this.

Rob asked you - "Is there more than 1 instance in a PMIC?" - and you did
not answer positively, just mentioned something about drivers in
downstream, which do not matter. So is the answer for that question:
yes, you have two instances of the same PMIC differing by presence of
PBS and other features"?

Best regards,
Krzysztof