--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Marvell International Ltd.
+ * Copyright (C) 2021 Stefan Roese <sr@denx.de>
+ */
+
+#include <dm.h>
+#include <dm/uclass.h>
+#include <errno.h>
+#include <input.h>
+#include <iomux.h>
+#include <log.h>
+#include <serial.h>
+#include <stdio_dev.h>
+#include <string.h>
+#include <watchdog.h>
+#include <linux/delay.h>
+#include <asm/addrspace.h>
+#include <asm/io.h>
+#include <mach/cvmx-regs.h>
+#include <mach/cvmx-bootmem.h>
+
+#define DRIVER_NAME "pci-bootcmd"
+
+/*
+ * Important:
+ * This address cannot be changed as the PCI console tool relies on exactly
+ * this value!
+ */
+#define BOOTLOADER_PCI_READ_BUFFER_BASE 0x6c000
+#define BOOTLOADER_PCI_READ_BUFFER_SIZE 256
+#define BOOTLOADER_PCI_WRITE_BUFFER_SIZE 256
+
+#define BOOTLOADER_PCI_READ_BUFFER_STR_LEN \
+ (BOOTLOADER_PCI_READ_BUFFER_SIZE - 8)
+#define BOOTLOADER_PCI_WRITE_BUFFER_STR_LEN \
+ (BOOTLOADER_PCI_WRITE_BUFFER_SIZE - 8)
+
+#define BOOTLOADER_PCI_READ_BUFFER_OWNER_ADDR \
+ (BOOTLOADER_PCI_READ_BUFFER_BASE + 0)
+#define BOOTLOADER_PCI_READ_BUFFER_LEN_ADDR \
+ (BOOTLOADER_PCI_READ_BUFFER_BASE + 4)
+#define BOOTLOADER_PCI_READ_BUFFER_DATA_ADDR \
+ (BOOTLOADER_PCI_READ_BUFFER_BASE + 8)
+
+enum octeon_pci_io_buf_owner {
+ /* Must be zero, set when memory cleared */
+ OCTEON_PCI_IO_BUF_OWNER_INVALID = 0,
+ OCTEON_PCI_IO_BUF_OWNER_OCTEON = 1,
+ OCTEON_PCI_IO_BUF_OWNER_HOST = 2,
+};
+
+/* Structure for bootloader PCI IO buffers */
+struct octeon_pci_io_buf {
+ u32 owner;
+ u32 len;
+ char data[0];
+};
+
+struct octeon_bootcmd_priv {
+ bool started;
+ int copy_offset;
+ bool eol;
+ bool unlocked;
+ struct octeon_pci_io_buf *buf;
+};
+
+static int octeon_bootcmd_pending(struct udevice *dev, bool input)
+{
+ struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
+
+ if (!input)
+ return 0;
+
+ if (priv->eol)
+ return 1;
+
+ CVMX_SYNC;
+ if (priv->buf->owner != OCTEON_PCI_IO_BUF_OWNER_OCTEON)
+ return 0;
+
+ if (priv->buf->len > priv->copy_offset &&
+ (priv->buf->data[priv->copy_offset] != '\0'))
+ return 1;
+
+ return 0;
+}
+
+static int octeon_bootcmd_getc(struct udevice *dev)
+{
+ struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
+ char c;
+
+ /* There's no EOL for boot commands so we fake it. */
+ if (priv->eol) {
+ priv->eol = false;
+ return '\n';
+ }
+
+ while (!octeon_bootcmd_pending(dev, true)) {
+ WATCHDOG_RESET();
+ /*
+ * ToDo:
+ * The original code calls octeon_board_poll() here. We may
+ * need to implement something similar here.
+ */
+ udelay(100);
+ }
+
+ c = priv->buf->data[priv->copy_offset];
+ priv->buf->data[priv->copy_offset++] = '\0';
+
+ if (priv->copy_offset >= min_t(int, CONFIG_SYS_CBSIZE - 1,
+ BOOTLOADER_PCI_READ_BUFFER_STR_LEN - 1) ||
+ (priv->buf->data[priv->copy_offset] == '\0')) {
+ priv->copy_offset = 0;
+ priv->buf->len = 0;
+ priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
+ priv->eol = true;
+ CVMX_SYNC;
+ }
+
+ return c;
+}
+
+static const struct dm_serial_ops octeon_bootcmd_ops = {
+ .getc = octeon_bootcmd_getc,
+ .pending = octeon_bootcmd_pending,
+};
+
+static int octeon_bootcmd_probe(struct udevice *dev)
+{
+ struct octeon_bootcmd_priv *priv = dev_get_priv(dev);
+
+ priv->buf = (void *)CKSEG0ADDR(BOOTLOADER_PCI_READ_BUFFER_BASE);
+ memset(priv->buf, 0, BOOTLOADER_PCI_READ_BUFFER_SIZE);
+ priv->eol = false;
+
+ /*
+ * When the bootcmd console is first started it is started as locked to
+ * block any calls sending a command until U-Boot is ready to accept
+ * commands. Just before the main loop starts to accept commands the
+ * bootcmd console is unlocked.
+ */
+ if (priv->unlocked)
+ priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
+ else
+ priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_OCTEON;
+
+ debug("%s called, buffer ptr: 0x%p, owner: %s\n", __func__,
+ priv->buf,
+ priv->buf->owner == OCTEON_PCI_IO_BUF_OWNER_HOST ?
+ "host" : "octeon");
+ debug("&priv->copy_offset: 0x%p\n", &priv->copy_offset);
+ CVMX_SYNC;
+
+ /*
+ * Perhaps reinvestige this: In the original code, "unlocked" etc
+ * is set in the octeon_pci_bootcmd_unlock() function called very
+ * late.
+ */
+ priv->buf->owner = OCTEON_PCI_IO_BUF_OWNER_HOST;
+ priv->unlocked = true;
+ priv->started = true;
+ CVMX_SYNC;
+
+ return 0;
+}
+
+static const struct udevice_id octeon_bootcmd_serial_id[] = {
+ { .compatible = "marvell,pci-bootcmd", },
+ { },
+};
+
+U_BOOT_DRIVER(octeon_bootcmd) = {
+ .name = DRIVER_NAME,
+ .id = UCLASS_SERIAL,
+ .ops = &octeon_bootcmd_ops,
+ .of_match = of_match_ptr(octeon_bootcmd_serial_id),
+ .probe = octeon_bootcmd_probe,
+ .priv_auto = sizeof(struct octeon_bootcmd_priv),
+};