Re: [PATCH v2 2/7] soc: qcom: smem: Add a feature code getter

[Dmitry Baryshkov]

On Wed, Apr 17, 2024 at 10:02:54PM +0200, Konrad Dybcio wrote:
> Recent (SM8550+ ish) Qualcomm SoCs have a new mechanism for precisely
> identifying the specific SKU and the precise speed bin (in the general
> meaning of this word, anyway): a pair of values called Product Code
> and Feature Code.
> 
> Based on this information, we can deduce the available frequencies for
> things such as Adreno. In the case of Adreno specifically, Pcode is
> useless for non-prototype SoCs.
> 
> Introduce a getter for the feature code and export it.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> ---
>  drivers/soc/qcom/smem.c          | 33 +++++++++++++++++++++++++++++++++
>  include/linux/soc/qcom/smem.h    |  1 +
>  include/linux/soc/qcom/socinfo.h | 26 ++++++++++++++++++++++++++
>  3 files changed, 60 insertions(+)
> 
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index 7191fa0c087f..29e708789eec 100644
> --- a/drivers/soc/qcom/smem.c
> +++ b/drivers/soc/qcom/smem.c
> @@ -795,6 +795,39 @@ int qcom_smem_get_soc_id(u32 *id)
>  }
>  EXPORT_SYMBOL_GPL(qcom_smem_get_soc_id);
>  
> +/**
> + * qcom_smem_get_feature_code() - return the feature code
> + * @code: On success, return the feature code here.
> + *
> + * Look up the feature code identifier from SMEM and return it.
> + *
> + * Return: 0 on success, negative errno on failure.
> + */
> +int qcom_smem_get_feature_code(u32 *code)
> +{
> +	struct socinfo *info;
> +	u32 raw_code;
> +
> +	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_HW_SW_BUILD_ID, NULL);
> +	if (IS_ERR(info))
> +		return PTR_ERR(info);
> +
> +	/* This only makes sense for socinfo >= 16 */
> +	if (__le32_to_cpu(info->fmt) < SOCINFO_VERSION(0, 16))
> +		return -EOPNOTSUPP;
> +
> +	raw_code = __le32_to_cpu(info->feature_code);
> +
> +	/* Ensure the value makes sense */
> +	if (raw_code >= SOCINFO_FC_INT_MAX)
> +		raw_code = SOCINFO_FC_UNKNOWN;
> +
> +	*code = raw_code;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_smem_get_feature_code);
> +
>  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 a36a3b9d4929..0943bf419e11 100644
> --- a/include/linux/soc/qcom/smem.h
> +++ b/include/linux/soc/qcom/smem.h
> @@ -13,5 +13,6 @@ 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);
> +int qcom_smem_get_feature_code(u32 *code);
>  
>  #endif
> diff --git a/include/linux/soc/qcom/socinfo.h b/include/linux/soc/qcom/socinfo.h
> index 10e0a4c287f4..52439f48428f 100644
> --- a/include/linux/soc/qcom/socinfo.h
> +++ b/include/linux/soc/qcom/socinfo.h
> @@ -3,6 +3,8 @@
>  #ifndef __QCOM_SOCINFO_H__
>  #define __QCOM_SOCINFO_H__
>  
> +#include <linux/types.h>
> +
>  /*
>   * SMEM item id, used to acquire handles to respective
>   * SMEM region.
> @@ -82,4 +84,28 @@ struct socinfo {
>  	__le32 boot_core;
>  };
>  
> +/* Internal feature codes */
> +enum qcom_socinfo_feature_code {
> +	/* External feature codes */
> +	SOCINFO_FC_UNKNOWN = 0x0,
> +	SOCINFO_FC_AA,
> +	SOCINFO_FC_AB,
> +	SOCINFO_FC_AC,
> +	SOCINFO_FC_AD,
> +	SOCINFO_FC_AE,
> +	SOCINFO_FC_AF,
> +	SOCINFO_FC_AG,
> +	SOCINFO_FC_AH,
> +};
> +
> +/* Internal feature codes */
> +/* Valid values: 0 <= n <= 0xf */
> +#define SOCINFO_FC_Yn(n)		(0xf1 + n)
> +#define SOCINFO_FC_INT_MAX		SOCINFO_FC_Yn(0x10)

This is 0x101 rather than 0x100 or 0xff. Is that expected?

> +
> +/* Product codes */
> +#define SOCINFO_PC_UNKNOWN		0
> +#define SOCINFO_PCn(n)			(n + 1)
> +#define SOCINFO_PC_RESERVE		(BIT(31) - 1)

This patch works on fcodes, why do we have PCode defines here?

> +
>  #endif
> 
> -- 
> 2.44.0
> 

-- 
With best wishes
Dmitry