[PATCH v5 15/17] firmware: scm: Modify only the download bits in TCSR register

[Mukesh Ojha]

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 at quicinc.com>
Signed-off-by: Mukesh Ojha <quic_mojha at quicinc.com>
---
 drivers/firmware/qcom_scm.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 5ea8fc4fd4e8..eda92f713019 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -5,6 +5,8 @@
 #include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
 #include <linux/completion.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
@@ -30,6 +32,10 @@ module_param(download_mode, bool, 0);
 #define SCM_HAS_IFACE_CLK	BIT(1)
 #define SCM_HAS_BUS_CLK		BIT(2)
 
+#define QCOM_DLOAD_MASK		GENMASK(5, 4)
+#define QCOM_DLOAD_FULLDUMP	0x1
+#define QCOM_DLOAD_NODUMP	0x0
+
 struct qcom_scm {
 	struct device *dev;
 	struct clk *core_clk;
@@ -444,6 +450,7 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 
 static void qcom_scm_set_download_mode(bool enable)
 {
+	u32 val = enable ? QCOM_DLOAD_FULLDUMP : QCOM_DLOAD_NODUMP;
 	bool avail;
 	int ret = 0;
 
@@ -453,8 +460,9 @@ 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);
+		ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
+					       QCOM_DLOAD_MASK,
+					       FIELD_PREP(QCOM_DLOAD_MASK, val));
 	} else {
 		dev_err(__scm->dev,
 			"No available mechanism for setting download mode\n");
-- 
2.7.4