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Diffstat (limited to 'drivers/allwinner/sunxi_msgbox.c')
-rw-r--r--drivers/allwinner/sunxi_msgbox.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/allwinner/sunxi_msgbox.c b/drivers/allwinner/sunxi_msgbox.c
new file mode 100644
index 0000000..cc4a6ff
--- /dev/null
+++ b/drivers/allwinner/sunxi_msgbox.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+
+#include <drivers/delay_timer.h>
+#include <lib/bakery_lock.h>
+#include <lib/mmio.h>
+#include <lib/utils_def.h>
+
+#include <sunxi_mmap.h>
+
+#define REMOTE_IRQ_EN_REG 0x0040
+#define REMOTE_IRQ_STAT_REG 0x0050
+#define LOCAL_IRQ_EN_REG 0x0060
+#define LOCAL_IRQ_STAT_REG 0x0070
+
+#define RX_IRQ(n) BIT(0 + 2 * (n))
+#define TX_IRQ(n) BIT(1 + 2 * (n))
+
+#define FIFO_STAT_REG(n) (0x0100 + 0x4 * (n))
+#define FIFO_STAT_MASK GENMASK(0, 0)
+
+#define MSG_STAT_REG(n) (0x0140 + 0x4 * (n))
+#define MSG_STAT_MASK GENMASK(2, 0)
+
+#define MSG_DATA_REG(n) (0x0180 + 0x4 * (n))
+
+#define RX_CHAN 1
+#define TX_CHAN 0
+
+#define MHU_MAX_SLOT_ID 31
+
+#define MHU_TIMEOUT_DELAY 10
+#define MHU_TIMEOUT_ITERS 10000
+
+static DEFINE_BAKERY_LOCK(mhu_secure_message_lock);
+
+static bool sunxi_msgbox_last_tx_done(unsigned int chan)
+{
+ uint32_t stat = mmio_read_32(SUNXI_MSGBOX_BASE + REMOTE_IRQ_STAT_REG);
+
+ return (stat & RX_IRQ(chan)) == 0U;
+}
+
+static bool sunxi_msgbox_peek_data(unsigned int chan)
+{
+ uint32_t stat = mmio_read_32(SUNXI_MSGBOX_BASE + MSG_STAT_REG(chan));
+
+ return (stat & MSG_STAT_MASK) != 0U;
+}
+
+void mhu_secure_message_start(unsigned int slot_id __unused)
+{
+ uint32_t timeout = MHU_TIMEOUT_ITERS;
+
+ bakery_lock_get(&mhu_secure_message_lock);
+
+ /* Wait for all previous messages to be acknowledged. */
+ while (!sunxi_msgbox_last_tx_done(TX_CHAN) && --timeout)
+ udelay(MHU_TIMEOUT_DELAY);
+}
+
+void mhu_secure_message_send(unsigned int slot_id)
+{
+ mmio_write_32(SUNXI_MSGBOX_BASE + MSG_DATA_REG(TX_CHAN), BIT(slot_id));
+}
+
+uint32_t mhu_secure_message_wait(void)
+{
+ uint32_t timeout = MHU_TIMEOUT_ITERS;
+ uint32_t msg = 0;
+
+ /* Wait for a message from the SCP. */
+ while (!sunxi_msgbox_peek_data(RX_CHAN) && --timeout)
+ udelay(MHU_TIMEOUT_DELAY);
+
+ /* Return the most recent message in the FIFO. */
+ while (sunxi_msgbox_peek_data(RX_CHAN))
+ msg = mmio_read_32(SUNXI_MSGBOX_BASE + MSG_DATA_REG(RX_CHAN));
+
+ return msg;
+}
+
+void mhu_secure_message_end(unsigned int slot_id)
+{
+ /* Acknowledge a response by clearing the IRQ status. */
+ mmio_write_32(SUNXI_MSGBOX_BASE + LOCAL_IRQ_STAT_REG, RX_IRQ(RX_CHAN));
+
+ bakery_lock_release(&mhu_secure_message_lock);
+}