// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (c) 2015 Google, Inc * Written by Simon Glass <sjg@chromium.org> */ #include <common.h> #include <debug_uart.h> #include <dm.h> #include <efi.h> #include <efi_api.h> #include <errno.h> #include <fdtdec.h> #include <linux/compiler.h> #include <asm/io.h> #include <serial.h> /* Information about the efi console */ struct serial_efi_priv { struct efi_simple_input_interface *con_in; struct efi_simple_text_output_protocol *con_out; struct efi_input_key key; bool have_key; }; int serial_efi_setbrg(struct udevice *dev, int baudrate) { return 0; } static int serial_efi_get_key(struct serial_efi_priv *priv) { int ret; if (priv->have_key) return 0; ret = priv->con_in->read_key_stroke(priv->con_in, &priv->key); if (ret == EFI_NOT_READY) return -EAGAIN; else if (ret != EFI_SUCCESS) return -EIO; priv->have_key = true; return 0; } static int serial_efi_getc(struct udevice *dev) { struct serial_efi_priv *priv = dev_get_priv(dev); int ret, ch; ret = serial_efi_get_key(priv); if (ret) return ret; priv->have_key = false; ch = priv->key.unicode_char; /* * Unicode char 8 (for backspace) is never returned. Instead we get a * key scan code of 8. Handle this so that backspace works correctly * in the U-Boot command line. */ if (!ch && priv->key.scan_code == 8) ch = 8; debug(" [%x %x %x] ", ch, priv->key.unicode_char, priv->key.scan_code); return ch; } static int serial_efi_putc(struct udevice *dev, const char ch) { struct serial_efi_priv *priv = dev_get_priv(dev); uint16_t ucode[2]; int ret; ucode[0] = ch; ucode[1] = '\0'; ret = priv->con_out->output_string(priv->con_out, ucode); if (ret) return -EIO; return 0; } static int serial_efi_pending(struct udevice *dev, bool input) { struct serial_efi_priv *priv = dev_get_priv(dev); int ret; /* We assume that EFI will stall if its output buffer fills up */ if (!input) return 0; ret = serial_efi_get_key(priv); if (ret == -EAGAIN) return 0; else if (ret) return ret; return 1; } /* * There is nothing to init here since the EFI console is already running by * the time we enter U-Boot. */ static inline void _debug_uart_init(void) { } static inline void _debug_uart_putc(int ch) { struct efi_system_table *sys_table = efi_get_sys_table(); uint16_t ucode[2]; ucode[0] = ch; ucode[1] = '\0'; sys_table->con_out->output_string(sys_table->con_out, ucode); } DEBUG_UART_FUNCS static int serial_efi_probe(struct udevice *dev) { struct efi_system_table *table = efi_get_sys_table(); struct serial_efi_priv *priv = dev_get_priv(dev); priv->con_in = table->con_in; priv->con_out = table->con_out; return 0; } static const struct dm_serial_ops serial_efi_ops = { .putc = serial_efi_putc, .getc = serial_efi_getc, .pending = serial_efi_pending, .setbrg = serial_efi_setbrg, }; static const struct udevice_id serial_efi_ids[] = { { .compatible = "efi,uart" }, { } }; U_BOOT_DRIVER(serial_efi) = { .name = "serial_efi", .id = UCLASS_SERIAL, .of_match = serial_efi_ids, .priv_auto_alloc_size = sizeof(struct serial_efi_priv), .probe = serial_efi_probe, .ops = &serial_efi_ops, .flags = DM_FLAG_PRE_RELOC, };