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Message-ID: <ed1f3496-184c-c9e1-8c46-1602d35effde@linaro.org>
Date:   Fri, 26 May 2023 10:42:58 +0200
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Subject: Re: [PATCH v4 3/5] soc: qcom: smem: introduce qcom_smem_get_soc_id()
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To:     Bjorn Andersson <andersson@kernel.org>
Cc:     Robert Marko <robimarko@gmail.com>, agross@kernel.org,
        ilia.lin@kernel.org, rafael@kernel.org, viresh.kumar@linaro.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-pm@vger.kernel.org, ansuelsmth@gmail.com
References: <20230525210214.78235-1-robimarko@gmail.com>
 <20230525210214.78235-3-robimarko@gmail.com>
 <a196330e-9d70-1bbd-6fae-7d60eb06e478@linaro.org>
 <20230526023325.y7iqygmbtjmbf4zo@ripper>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <20230526023325.y7iqygmbtjmbf4zo@ripper>
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On 26.05.2023 04:33, Bjorn Andersson wrote:
> On Fri, May 26, 2023 at 01:18:17AM +0200, Konrad Dybcio wrote:
>>
>>
>> On 25.05.2023 23:02, Robert Marko wrote:
>>> Introduce a helper to return the SoC SMEM ID, which is used to identify the
>>> exact SoC model as there may be differences in the same SoC family.
>>>
>>> Currently, cpufreq-nvmem does this completely in the driver and there has
>>> been more interest expresed for other drivers to use this information so
>>> lets expose a common helper to prevent redoing it in individual drivers
>>> since this field is present on every SMEM table version.
>>>
>>> Signed-off-by: Robert Marko <robimarko@gmail.com>
>>> ---
>>> Changes in v4:
>>> * Change helper name to qcom_smem_get_soc_id()
>>> * Remove len and just pass NULL, that is sufficient here
>>>
>>> Changes in v3:
>>> * Change export to EXPORT_SYMBOL_GPL
>>> * Use an argument for returning SoC ID
>>> * Update kerneldoc
>>> ---
>>>  drivers/soc/qcom/smem.c       | 23 +++++++++++++++++++++++
>>>  include/linux/soc/qcom/smem.h |  2 ++
>>>  2 files changed, 25 insertions(+)
>>>
>>> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
>>> index bc98520c4969..78cf79ea4924 100644
>>> --- a/drivers/soc/qcom/smem.c
>>> +++ b/drivers/soc/qcom/smem.c
>>> @@ -14,6 +14,7 @@
>>>  #include <linux/sizes.h>
>>>  #include <linux/slab.h>
>>>  #include <linux/soc/qcom/smem.h>
>>> +#include <linux/soc/qcom/socinfo.h>
>>>  
>>>  /*
>>>   * The Qualcomm shared memory system is a allocate only heap structure that
>>> @@ -772,6 +773,28 @@ phys_addr_t qcom_smem_virt_to_phys(void *p)
>>>  }
>>>  EXPORT_SYMBOL_GPL(qcom_smem_virt_to_phys);
>>>  
>>> +/**
>>> + * qcom_smem_get_soc_id() - return the SoC ID
>>> + * @id:	On success, we return the SoC ID here.
>>> + *
>>> + * Look up SoC ID from HW/SW build ID and return it.
>>> + *
>>> + * Return: 0 on success, negative errno on failure.
>>> + */
>>> +int qcom_smem_get_soc_id(u32 *id)
>> __le32 *id
>>
> 
> Why do you want this passed back to the user in little endian? When is
> it not going to be compared to a cpu-endian constant?
Ugh. You're right. This makes no sense.

Konrad
> 
>> LGTM otherwise!
>>
>> Konrad
>>> +{
>>> +	struct socinfo *info;
>>> +
>>> +	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_HW_SW_BUILD_ID, NULL);
>>> +	if (IS_ERR(info))
>>> +		return PTR_ERR(info);
>>> +
>>> +	*id = info->id;
> 
> This should be __le32_to_cpu() though...
> 
> Regards,
> Bjorn
> 
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(qcom_smem_get_soc_id);
>>> +
>>>  static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
>>>  {
>>>  	struct smem_header *header;
>>> diff --git a/include/linux/soc/qcom/smem.h b/include/linux/soc/qcom/smem.h
>>> index 86e1b358688a..223db6a9c733 100644
>>> --- a/include/linux/soc/qcom/smem.h
>>> +++ b/include/linux/soc/qcom/smem.h
>>> @@ -11,4 +11,6 @@ int qcom_smem_get_free_space(unsigned host);
>>>  
>>>  phys_addr_t qcom_smem_virt_to_phys(void *p);
>>>  
>>> +int qcom_smem_get_soc_id(u32 *id);
>>> +
>>>  #endif