allwinner: Add a msgbox driver for use with SCPI

The function names follow the naming convention used by the existing
ARM SCPI client.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I543bae7d46e206eb405dbedfcf7aeba88a12ca48

diff --git a/drivers/allwinner/sunxi_msgbox.c b/drivers/allwinner/sunxi_msgbox.c
new file mode 100644 (file)
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);
+}

diff --git a/plat/allwinner/common/allwinner-common.mk b/plat/allwinner/common/allwinner-common.mk
index 98bcf3e225d5c09966f67bb1aea6614aca7b954e..83a7992b3f3d00f5a7a29a19c18e2237ec282ba3 100644 (file)
--- a/plat/allwinner/common/allwinner-common.mk
+++ b/plat/allwinner/common/allwinner-common.mk
@@ -20,6 +20,7 @@ PLAT_BL_COMMON_SOURCES        :=      drivers/ti/uart/${ARCH}/16550_console.S \
                                ${AW_PLAT}/common/sunxi_common.c
 
 BL31_SOURCES           +=      drivers/allwinner/axp/common.c          \
+                               drivers/allwinner/sunxi_msgbox.c        \
                                drivers/arm/gic/common/gic_common.c     \
                                drivers/arm/gic/v2/gicv2_helpers.c      \
                                drivers/arm/gic/v2/gicv2_main.c         \