[PATCH 3/5] firmware: scm: Modify only the DLOAD bit in TCSR register for download mode

[Poovendhan Selvaraj]

Add support to read-modify-write TCSR register to modify only DLOAD bit.

Co-developed-by: Anusha Rao <quic_anusha@xxxxxxxxxxx>
Signed-off-by: Anusha Rao <quic_anusha@xxxxxxxxxxx>
Co-developed-by: Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx>
Signed-off-by: Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx>
Signed-off-by: Poovendhan Selvaraj <quic_poovendh@xxxxxxxxxxx>
---
 drivers/firmware/qcom_scm.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index cdbfe54c8146..b56d8f465f71 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -400,7 +400,7 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
 }
 EXPORT_SYMBOL(qcom_scm_set_remote_state);
 
-static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
+static int __qcom_scm_set_dload_mode(struct device *dev, u32 val, bool enable)
 {
 	struct qcom_scm_desc desc = {
 		.svc = QCOM_SCM_SVC_BOOT,
@@ -410,7 +410,7 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 		.owner = ARM_SMCCC_OWNER_SIP,
 	};
 
-	desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
+	desc.args[1] = enable ? val | QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
 
 	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
@@ -419,15 +419,19 @@ static void qcom_scm_set_download_mode(bool enable)
 {
 	bool avail;
 	int ret = 0;
+	u32 dload_addr_val;
 
 	avail = __qcom_scm_is_call_available(__scm->dev,
 					     QCOM_SCM_SVC_BOOT,
 					     QCOM_SCM_BOOT_SET_DLOAD_MODE);
+	ret = qcom_scm_io_readl(__scm->dload_mode_addr, &dload_addr_val);
+
 	if (avail) {
-		ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
+		ret = __qcom_scm_set_dload_mode(__scm->dev, dload_addr_val, enable);
 	} else if (__scm->dload_mode_addr) {
 		ret = qcom_scm_io_writel(__scm->dload_mode_addr,
-				enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0);
+				enable ? dload_addr_val |
+					QCOM_SCM_BOOT_SET_DLOAD_MODE : 0);
 	} else {
 		dev_err(__scm->dev,
 			"No available mechanism for setting download mode\n");
-- 
2.17.1