[PATCH v3 1/1] xilinx: zynqmp: Enable reset_cpu() in SPL

[lukas.funke-oss at weidmueller.com]

From: Lukas Funke <lukas.funke at weidmueller.com>

This commit enables SPL to reset the CPU via PMU-firmware. The usual
reset mechanism requires bl31 to be loaded which may not be the case in
SPL.

Signed-off-by: Lukas Funke <lukas.funke at weidmueller.com>
---

Changes in v3:
- Use 'ZYNQMP_PM_RESET_SOFT' directly
- Add comment on what happens if CONFIG_ZYNQMP_FIRMWARE is not enabled

Changes in v2:
- Drop 2/2 since reworking ZYNQMP_FIRMWARE dependency is out-of-scope

 board/xilinx/zynqmp/zynqmp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index f370fb7347a..c37c198ec55 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -285,6 +285,18 @@ int dram_init(void)
 #if !CONFIG_IS_ENABLED(SYSRESET)
 void reset_cpu(void)
 {
+	if (!IS_ENABLED(CONFIG_ZYNQMP_FIRMWARE)) {
+		log_warning("reset failed: ZYNQMP_FIRMWARE disabled");
+		return;
+	}
+
+	/* In case of !CONFIG_ZYNQMP_FIRMWARE the call to 'xilinx_pm_request()'
+	 * will be removed by the compiler due to the early return.
+	 * If CONFIG_ZYNQMP_FIRMWARE is defined in SPL 'xilinx_pm_request()'
+	 * will send command over IPI and requires pmufw to be present.
+	 */
+	xilinx_pm_request(PM_RESET_ASSERT, ZYNQMP_PM_RESET_SOFT,
+			  PM_RESET_ACTION_ASSERT, 0, 0, NULL);
 }
 #endif
 
-- 
2.30.2