[PATCH V5 3/3] firmware: scm: Modify only the download bits in TCSR register

[Kathiravan T <quic_kathirav@xxxxxxxxxxx>]

From: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>

CrashDump collection is based on the DLOAD bit of TCSR register. To retain
other bits, we read the register and modify only the DLOAD bit as the
other bits have their own significance.

Co-developed-by: Poovendhan Selvaraj <quic_poovendh@xxxxxxxxxxx>
Signed-off-by: Poovendhan Selvaraj <quic_poovendh@xxxxxxxxxxx>
Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
Signed-off-by: Kathiravan T <quic_kathirav@xxxxxxxxxxx>
---
Changes in V5:
	- Added the Signed-off-by tag for user Poovendhan
	- Dropped the macro QCOM_DOWNLOAD_MODE_SHIFT in the favor of
	  PREP_FIELD

 drivers/firmware/qcom_scm.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 104d86e49b97..3830dcf14326 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -30,6 +30,10 @@ module_param(download_mode, bool, 0);
 #define SCM_HAS_IFACE_CLK	BIT(1)
 #define SCM_HAS_BUS_CLK		BIT(2)
 
+#define QCOM_DOWNLOAD_FULLDUMP		0x1
+#define QCOM_DOWNLOAD_NODUMP		0x0
+#define QCOM_DOWNLOAD_MODE_MASK		BIT(4)
+
 struct qcom_scm {
 	struct device *dev;
 	struct clk *core_clk;
@@ -440,6 +444,7 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 static void qcom_scm_set_download_mode(bool enable)
 {
 	bool avail;
+	int val;
 	int ret = 0;
 
 	avail = __qcom_scm_is_call_available(__scm->dev,
@@ -448,8 +453,10 @@ static void qcom_scm_set_download_mode(bool enable)
 	if (avail) {
 		ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
 	} else if (__scm->dload_mode_addr) {
-		ret = qcom_scm_io_writel(__scm->dload_mode_addr,
-				enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0);
+		val = enable ? QCOM_DOWNLOAD_FULLDUMP : QCOM_DOWNLOAD_NODUMP;
+		ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
+					       QCOM_DOWNLOAD_MODE_MASK,
+					       FIELD_PREP(QCOM_DOWNLOAD_MODE_MASK, val));
 	} else {
 		dev_err(__scm->dev,
 			"No available mechanism for setting download mode\n");
-- 
2.34.1