1 files changed, 131 insertions, 0 deletions
diff --git a/plat/brcm/common/brcm_mhu.c b/plat/brcm/common/brcm_mhu.c
new file mode 100644
index 0000000..56f44e0
--- /dev/null
+++ b/plat/brcm/common/brcm_mhu.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#include <drivers/delay_timer.h>
+#include <lib/bakery_lock.h>
+
+#include <brcm_mhu.h>
+#include <platform_def.h>
+
+#include "m0_ipc.h"
+
+#define PLAT_MHU_INTR_REG	AP_TO_SCP_MAILBOX1
+
+/* SCP MHU secure channel registers */
+#define SCP_INTR_S_STAT		CRMU_IHOST_SW_PERSISTENT_REG11
+#define SCP_INTR_S_SET		CRMU_IHOST_SW_PERSISTENT_REG11
+#define SCP_INTR_S_CLEAR	CRMU_IHOST_SW_PERSISTENT_REG11
+
+/* CPU MHU secure channel registers */
+#define CPU_INTR_S_STAT		CRMU_IHOST_SW_PERSISTENT_REG10
+#define CPU_INTR_S_SET		CRMU_IHOST_SW_PERSISTENT_REG10
+#define CPU_INTR_S_CLEAR	CRMU_IHOST_SW_PERSISTENT_REG10
+
+static DEFINE_BAKERY_LOCK(bcm_lock);
+
+/*
+ * Slot 31 is reserved because the MHU hardware uses this register bit to
+ * indicate a non-secure access attempt. The total number of available slots is
+ * therefore 31 [30:0].
+ */
+#define MHU_MAX_SLOT_ID		30
+
+void mhu_secure_message_start(unsigned int slot_id)
+{
+	int iter = 1000000;
+
+	assert(slot_id <= MHU_MAX_SLOT_ID);
+
+	bakery_lock_get(&bcm_lock);
+	/* Make sure any previous command has finished */
+	do {
+		if (!(mmio_read_32(PLAT_BRCM_MHU_BASE + CPU_INTR_S_STAT) &
+		   (1 << slot_id)))
+			break;
+
+		 udelay(1);
+
+	} while (--iter);
+
+	assert(iter != 0);
+}
+
+void mhu_secure_message_send(unsigned int slot_id)
+{
+	uint32_t response, iter = 1000000;
+
+	assert(slot_id <= MHU_MAX_SLOT_ID);
+	assert(!(mmio_read_32(PLAT_BRCM_MHU_BASE + CPU_INTR_S_STAT) &
+							(1 << slot_id)));
+
+	/* Send command to SCP */
+	mmio_setbits_32(PLAT_BRCM_MHU_BASE + CPU_INTR_S_SET, 1 << slot_id);
+	mmio_write_32(CRMU_MAIL_BOX0, MCU_IPC_MCU_CMD_SCPI);
+	mmio_write_32(PLAT_BRCM_MHU_BASE + PLAT_MHU_INTR_REG, 0x1);
+
+	/* Wait until IPC transport acknowledges reception of SCP command */
+	do {
+		response = mmio_read_32(CRMU_MAIL_BOX0);
+		if ((response & ~MCU_IPC_CMD_REPLY_MASK) ==
+		   (MCU_IPC_CMD_DONE_MASK | MCU_IPC_MCU_CMD_SCPI))
+			break;
+
+		udelay(1);
+
+	} while (--iter);
+
+	assert(iter != 0);
+}
+
+uint32_t mhu_secure_message_wait(void)
+{
+	/* Wait for response from SCP */
+	uint32_t response, iter = 1000000;
+
+	do {
+		response = mmio_read_32(PLAT_BRCM_MHU_BASE + SCP_INTR_S_STAT);
+		if (!response)
+			break;
+
+		udelay(1);
+	} while (--iter);
+	assert(iter != 0);
+
+	return response;
+}
+
+void mhu_secure_message_end(unsigned int slot_id)
+{
+	assert(slot_id <= MHU_MAX_SLOT_ID);
+
+	/*
+	 * Clear any response we got by writing one in the relevant slot bit to
+	 * the CLEAR register
+	 */
+	mmio_clrbits_32(PLAT_BRCM_MHU_BASE + SCP_INTR_S_CLEAR, 1 << slot_id);
+	bakery_lock_release(&bcm_lock);
+}
+
+void mhu_secure_init(void)
+{
+	bakery_lock_init(&bcm_lock);
+
+	/*
+	 * The STAT register resets to zero. Ensure it is in the expected state,
+	 * as a stale or garbage value would make us think it's a message we've
+	 * already sent.
+	 */
+	mmio_write_32(PLAT_BRCM_MHU_BASE + CPU_INTR_S_STAT, 0);
+	mmio_write_32(PLAT_BRCM_MHU_BASE + SCP_INTR_S_STAT, 0);
+}
+
+void plat_brcm_pwrc_setup(void)
+{
+	mhu_secure_init();
+}