[PATCH v2 2/4] soc: qcom: smem: introduce qcom_smem_get_msm_id()

[Robert Marko]

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@xxxxxxxxx>
---
 drivers/soc/qcom/smem.c       | 19 +++++++++++++++++++
 include/linux/soc/qcom/smem.h |  2 ++
 2 files changed, 21 insertions(+)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 6be7ea93c78c..0d6ba9bce8cb 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 +773,24 @@ phys_addr_t qcom_smem_virt_to_phys(void *p)
 }
 EXPORT_SYMBOL(qcom_smem_virt_to_phys);
 
+/**
+ * qcom_smem_get_msm_id() - return the SoC ID
+ *
+ * Look up SoC ID from HW/SW build ID and return it.
+ */
+int qcom_smem_get_msm_id(void)
+{
+	size_t len;
+	struct socinfo *info;
+
+	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_HW_SW_BUILD_ID, &len);
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+
+	return __le32_to_cpu(info->id);
+}
+EXPORT_SYMBOL(qcom_smem_get_msm_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..6448607239e6 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_msm_id(void);
+
 #endif
-- 
2.40.1