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

[Kathiravan Thirumoorthy]

On 9/10/2023 1:46 AM, Mukesh Ojha wrote:
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>
---


This change doesn't cleanly apply on next-20230911. Please rebase it.

Validated this change on IPQ9574 and IPQ5332 and system is entering into 
the download mode.

Tested-by: Kathiravan Thirumoorthy <quic_kathi...@quicinc.com> # IPQ9574 
and IPQ5332


  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");