soc: qcom: rpmh: Add support to read back resource settings

All rpmh_*() APIs so far have supported placing votes for various resource
settings but the H/W also have option to read resource settings.

Add new rpmh_read() API to allow clients to read back resource setting
from H/W. This will be useful for clients like regulators, which currently
don't have a way to know the settings applied during bootloader stage.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
Signed-off-by: Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com>
Link: https://patch.msgid.link/20260801-b4-read-rpmh-v5-v6-1-9fcb54928523@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 7 insertions, 0 deletions

diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
index bdbee1a97d36..14ecbf242b6b 100644
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -11,6 +11,8 @@
 
 
 #if IS_ENABLED(CONFIG_QCOM_RPMH)
+int rpmh_read(const struct device *dev, struct tcs_cmd *cmd);
+
 int rpmh_write(const struct device *dev, enum rpmh_state state,
 	       const struct tcs_cmd *cmd, u32 n);
 
@@ -24,6 +26,9 @@ void rpmh_invalidate(const struct device *dev);
 
 #else
 
+static inline int rpmh_read(const struct device *dev, struct tcs_cmd *cmd)
+{ return -ENODEV; }
+
 static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
 			     const struct tcs_cmd *cmd, u32 n)
 { return -ENODEV; }
diff --git a/include/soc/qcom/tcs.h b/include/soc/qcom/tcs.h
index cff67ce25488..45b8513be2f9 100644
--- a/include/soc/qcom/tcs.h
+++ b/include/soc/qcom/tcs.h
@@ -51,6 +51,7 @@ struct tcs_cmd {
  * struct tcs_request: A set of tcs_cmds sent together in a TCS
  *
  * @state:          state for the request.
+ * @is_read:        set for read only requests
  * @wait_for_compl: wait until we get a response from the h/w accelerator
  *                  (same as setting cmd->wait for all commands in the request)
  * @num_cmds:       the number of @cmds in this request
@@ -58,6 +59,7 @@ struct tcs_cmd {
  */
 struct tcs_request {
 	enum rpmh_state state;
+	bool is_read;
 	u32 wait_for_compl;
 	u32 num_cmds;
 	struct tcs_cmd *cmds;