[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_poove...@quicinc.com>
Signed-off-by: Mukesh Ojha <quic_mo...@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