platform/x86: intel_pmc_ipc: Add read64 API

Add intel_pmc_gcr_read64() API for reading from 64-bit GCR registers.
This API will be called from intel_telemetry. Update description of
intel_pmc_gcr_read().

Signed-off-by: Souvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

1 files changed, 31 insertions, 2 deletions

diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
index e03fa31446ca..e7edc8c63936 100644
--- a/drivers/platform/x86/intel_pmc_ipc.c
+++ b/drivers/platform/x86/intel_pmc_ipc.c
@@ -215,11 +215,11 @@ static inline int is_gcr_valid(u32 offset)
 }
 
 /**
- * intel_pmc_gcr_read() - Read PMC GCR register
+ * intel_pmc_gcr_read() - Read a 32-bit PMC GCR register
  * @offset:     offset of GCR register from GCR address base
  * @data:       data pointer for storing the register output
  *
- * Reads the PMC GCR register of given offset.
+ * Reads the 32-bit PMC GCR register at given offset.
  *
  * Return:      negative value on error or 0 on success.
  */
@@ -244,6 +244,35 @@ int intel_pmc_gcr_read(u32 offset, u32 *data)
 EXPORT_SYMBOL_GPL(intel_pmc_gcr_read);
 
 /**
+ * intel_pmc_gcr_read64() - Read a 64-bit PMC GCR register
+ * @offset:     offset of GCR register from GCR address base
+ * @data:       data pointer for storing the register output
+ *
+ * Reads the 64-bit PMC GCR register at given offset.
+ *
+ * Return:      negative value on error or 0 on success.
+ */
+int intel_pmc_gcr_read64(u32 offset, u64 *data)
+{
+        int ret;
+
+        spin_lock(&ipcdev.gcr_lock);
+
+        ret = is_gcr_valid(offset);
+        if (ret < 0) {
+                spin_unlock(&ipcdev.gcr_lock);
+                return ret;
+        }
+
+        *data = readq(ipcdev.gcr_mem_base + offset);
+
+        spin_unlock(&ipcdev.gcr_lock);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(intel_pmc_gcr_read64);
+
+/**
  * intel_pmc_gcr_write() - Write PMC GCR register
  * @offset:     offset of GCR register from GCR address base
  * @data:       register update value