Not all RPM firmware versions have the dynamic sleep stats offset
available. Older versions use a fixed offset of 0xdba0.

Add support for this using a new qcom,rpm-legacy-stats compatible
that can be used for older SoCs like MSM8916.

Suggested-by: Maulik Shah <redacted>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
  drivers/soc/qcom/qcom_stats.c | 10 ++++++++++
  1 file changed, 10 insertions(+)

diff --git a/drivers/soc/qcom/qcom_stats.c b/drivers/soc/qcom/qcom_stats.c
index 817505bd99b5..67728de718fd 100644
--- a/drivers/soc/qcom/qcom_stats.c
+++ b/drivers/soc/qcom/qcom_stats.c

@@ -237,6 +237,15 @@ static const struct stats_config rpm_data = {
  	.subsystem_stats_in_smem = false,
  };
  
+/* Older RPM firmwares have the stats at a fixed offset instead */
+static const struct stats_config rpm_legacy_data = {
+	.stats_offset = 0xdba0,
+	.num_records = 2,
+	.appended_stats_avail = true,
+	.dynamic_offset = false,
+	.subsystem_stats_in_smem = false,
+};
+
  static const struct stats_config rpmh_data = {
  	.stats_offset = 0x48,
  	.num_records = 3,

@@ -247,6 +256,7 @@ static const struct stats_config rpmh_data = {
  
  static const struct of_device_id qcom_stats_table[] = {
  	{ .compatible = "qcom,rpm-stats", .data = &rpm_data },
+	{ .compatible = "qcom,rpm-legacy-stats", .data = &rpm_legacy_data },
  	{ .compatible = "qcom,rpmh-stats", .data = &rpmh_data },
  	{ }
  };