[PATCH 4/4] remoteproc: qcom: q6v5-pil: Add PDC restart for modem on SDM845 SoCs

[Sibi Sankar]

In the presence of a PDC block working with subsystem RSC,
assert/deassert PDC restart in modem start/stop path.

Signed-off-by: Sibi Sankar <si...@codeaurora.org>
---
 .../bindings/remoteproc/qcom,q6v5.txt         |  4 +++
 drivers/remoteproc/qcom_q6v5_pil.c            | 27 ++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt 
b/Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt
index 601dd9f389aa..124fb1dc6fb8 100644
--- a/Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt
+++ b/Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt
@@ -51,6 +51,8 @@ on the Qualcomm Hexagon core.
        Usage: required
        Value type: <phandle>
        Definition: reference to the reset-controller for the modem sub-system
+                   reference to the list of 2 reset-controllers for the modem
+                   sub-system on SDM845 SoCs
                    reference to the list of 3 reset-controllers for the
                    wcss sub-system
 
@@ -58,6 +60,8 @@ on the Qualcomm Hexagon core.
        Usage: required
        Value type: <stringlist>
        Definition: must be "mss_restart" for the modem sub-system
+       Definition: must be "mss_restart", "pdc_restart" for the modem
+                   sub-system on SDM845 SoCs
        Definition: must be "wcss_aon_reset", "wcss_reset", "wcss_q6_reset"
                    for the wcss syb-system
 
diff --git a/drivers/remoteproc/qcom_q6v5_pil.c 
b/drivers/remoteproc/qcom_q6v5_pil.c
index d57fdb34e3dd..5be794639fc3 100644
--- a/drivers/remoteproc/qcom_q6v5_pil.c
+++ b/drivers/remoteproc/qcom_q6v5_pil.c
@@ -149,6 +149,7 @@ struct q6v5 {
        u32 halt_nc;
 
        struct reset_control *mss_restart;
+       struct reset_control *pdc_restart;
 
        struct qcom_q6v5 q6v5;
 
@@ -349,10 +350,17 @@ static int q6v5_load(struct rproc *rproc, const struct 
firmware *fw)
 
 static int q6v5_reset_assert(struct q6v5 *qproc)
 {
-       if (qproc->has_alt_reset)
-               return reset_control_reset(qproc->mss_restart);
-       else
-               return reset_control_assert(qproc->mss_restart);
+       int ret;
+
+       if (qproc->has_alt_reset) {
+               reset_control_assert(qproc->pdc_restart);
+               ret = reset_control_reset(qproc->mss_restart);
+               reset_control_deassert(qproc->pdc_restart);
+       } else {
+               ret = reset_control_assert(qproc->mss_restart);
+       }
+
+       return ret;
 }
 
 static int q6v5_reset_deassert(struct q6v5 *qproc)
@@ -360,9 +368,11 @@ static int q6v5_reset_deassert(struct q6v5 *qproc)
        int ret;
 
        if (qproc->has_alt_reset) {
+               reset_control_assert(qproc->pdc_restart);
                writel(1, qproc->rmb_base + RMB_MBA_ALT_RESET);
                ret = reset_control_reset(qproc->mss_restart);
                writel(0, qproc->rmb_base + RMB_MBA_ALT_RESET);
+               reset_control_deassert(qproc->pdc_restart);
        } else {
                ret = reset_control_deassert(qproc->mss_restart);
        }
@@ -1182,6 +1192,15 @@ static int q6v5_init_reset(struct q6v5 *qproc)
                return PTR_ERR(qproc->mss_restart);
        }
 
+       if (qproc->has_alt_reset) {
+               qproc->pdc_restart = devm_reset_control_get(qproc->dev,
+                                                           "pdc_restart");
+               if (IS_ERR(qproc->pdc_restart)) {
+                       dev_err(qproc->dev, "failed to acquire pdc restart\n");
+                       return PTR_ERR(qproc->pdc_restart);
+               }
+       }
+
        return 0;
 }
 
-- 
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