remoteproc: xlnx: Avoid RPU force power down

Powering off RPU using force_pwrdwn call results in system failure
if there are multiple users of that RPU node. Better mechanism is to use
request_node and release_node EEMI calls. With use of these EEMI calls,
platform management controller will take-care of powering off RPU
when there is no user.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Link: https://lore.kernel.org/r/20250506165944.1109534-1-tanmay.shah@amd.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
index 5aeedea..1af8978 100644 (file)
--- a/drivers/remoteproc/xlnx_r5_remoteproc.c
+++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
@@ -380,6 +380,18 @@ static int zynqmp_r5_rproc_start(struct rproc *rproc)
        dev_dbg(r5_core->dev, "RPU boot addr 0x%llx from %s.", rproc->bootaddr,
                bootmem == PM_RPU_BOOTMEM_HIVEC ? "OCM" : "TCM");
 
+       /* Request node before starting RPU core if new version of API is supported */
+       if (zynqmp_pm_feature(PM_REQUEST_NODE) > 1) {
+               ret = zynqmp_pm_request_node(r5_core->pm_domain_id,
+                                            ZYNQMP_PM_CAPABILITY_ACCESS, 0,
+                                            ZYNQMP_PM_REQUEST_ACK_BLOCKING);
+               if (ret < 0) {
+                       dev_err(r5_core->dev, "failed to request 0x%x",
+                               r5_core->pm_domain_id);
+                       return ret;
+               }
+       }
+
        ret = zynqmp_pm_request_wake(r5_core->pm_domain_id, 1,
                                     bootmem, ZYNQMP_PM_REQUEST_ACK_NO);
        if (ret)
@@ -401,10 +413,30 @@ static int zynqmp_r5_rproc_stop(struct rproc *rproc)
        struct zynqmp_r5_core *r5_core = rproc->priv;
        int ret;
 
+       /* Use release node API to stop core if new version of API is supported */
+       if (zynqmp_pm_feature(PM_RELEASE_NODE) > 1) {
+               ret = zynqmp_pm_release_node(r5_core->pm_domain_id);
+               if (ret)
+                       dev_err(r5_core->dev, "failed to stop remoteproc RPU %d\n", ret);
+               return ret;
+       }
+
+       /*
+        * Check expected version of EEMI call before calling it. This avoids
+        * any error or warning prints from firmware as it is expected that fw
+        * doesn't support it.
+        */
+       if (zynqmp_pm_feature(PM_FORCE_POWERDOWN) != 1) {
+               dev_dbg(r5_core->dev, "EEMI interface %d ver 1 not supported\n",
+                       PM_FORCE_POWERDOWN);
+               return -EOPNOTSUPP;
+       }
+
+       /* maintain force pwr down for backward compatibility */
        ret = zynqmp_pm_force_pwrdwn(r5_core->pm_domain_id,
                                     ZYNQMP_PM_REQUEST_ACK_BLOCKING);
        if (ret)
-               dev_err(r5_core->dev, "failed to stop remoteproc RPU %d\n", ret);
+               dev_err(r5_core->dev, "core force power down failed\n");
 
        return ret;
 }