plat: marvell: armada: a3k: support doing system reset via CM3 secure coprocessor
Introduce a new build option CM3_SYSTEM_RESET for A3700 platform, which,
when enabled, adds code to the PSCI reset handler to try to do system
reset by the WTMI firmware running on the Cortex-M3 secure coprocessor.
(This function is exposed via the mailbox interface.)
The reason is that the Turris MOX board has a HW bug which causes reset
to hang unpredictably. This issue can be solved by putting the board in
a specific state before reset.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Change-Id: I3f60b9f244f334adcd33d6db6a361fbc8b8d209f
diff --git a/plat/marvell/armada/a3k/common/cm3_system_reset.c b/plat/marvell/armada/a3k/common/cm3_system_reset.c
new file mode 100644
index 0000000..548ff51
--- /dev/null
+++ b/plat/marvell/armada/a3k/common/cm3_system_reset.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2020 Marek Behun, CZ.NIC
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ * https://spdx.org/licenses
+ */
+
+#include <stdbool.h>
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <lib/mmio.h>
+
+#include <mvebu_def.h>
+
+/* Cortex-M3 Secure Processor Mailbox Registers */
+#define MVEBU_RWTM_PARAM0_REG (MVEBU_RWTM_REG_BASE)
+#define MVEBU_RWTM_CMD_REG (MVEBU_RWTM_REG_BASE + 0x40)
+#define MVEBU_RWTM_HOST_INT_RESET_REG (MVEBU_RWTM_REG_BASE + 0xC8)
+#define MVEBU_RWTM_HOST_INT_MASK_REG (MVEBU_RWTM_REG_BASE + 0xCC)
+#define MVEBU_RWTM_HOST_INT_SP_COMPLETE BIT(0)
+
+#define MVEBU_RWTM_REBOOT_CMD 0x0009
+#define MVEBU_RWTM_REBOOT_MAGIC 0xDEADBEEF
+
+static inline bool rwtm_completed(void)
+{
+ return (mmio_read_32(MVEBU_RWTM_HOST_INT_RESET_REG) &
+ MVEBU_RWTM_HOST_INT_SP_COMPLETE) != 0;
+}
+
+static bool rwtm_wait(int ms)
+{
+ while (ms && !rwtm_completed()) {
+ mdelay(1);
+ --ms;
+ }
+
+ return rwtm_completed();
+}
+
+void cm3_system_reset(void)
+{
+ int tries = 5;
+
+ for (; tries > 0; --tries) {
+ mmio_clrbits_32(MVEBU_RWTM_HOST_INT_RESET_REG,
+ MVEBU_RWTM_HOST_INT_SP_COMPLETE);
+
+ mmio_write_32(MVEBU_RWTM_PARAM0_REG, MVEBU_RWTM_REBOOT_MAGIC);
+ mmio_write_32(MVEBU_RWTM_CMD_REG, MVEBU_RWTM_REBOOT_CMD);
+
+ if (rwtm_wait(10)) {
+ break;
+ }
+
+ mdelay(100);
+ }
+
+ /* If we reach here, the command is not implemented. */
+ ERROR("System reset command not implemented in WTMI firmware!\n");
+}