Add a serial driver which makes use of EFI's console in/out service.
Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com Tested on Intel Crown Bay and QEMU Tested-by: Bin Meng bmeng.cn@gmail.com
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Changes in v3: None Changes in v2: - Add a comment about special handling for backspace - Add a comment as to why debug_uart_init() is empty - Drop unused DECLARE_GLOBAL_DATA_PTR - Rename CONFIG_ARCH_EFI to CONFIG_EFI_APP - Rename EFI debug UART to EFI_CONSOLE - Replace serial_s5p with serial_efi
drivers/serial/Kconfig | 9 +++ drivers/serial/Makefile | 1 + drivers/serial/serial_efi.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 167 insertions(+) create mode 100644 drivers/serial/serial_efi.c
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 078246d..b5a91b7 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -44,6 +44,15 @@ config DEBUG_UART_NS16550 will need to provide parameters to make this work. The driver will be available until the real driver model serial is running.
+config DEBUG_EFI_CONSOLE + bool "EFI" + depends on EFI_APP + help + Select this to enable a debug console which calls back to EFI to + output to the console. This can be useful for early debugging of + U-Boot when running on top of EFI (Extensive Firmware Interface). + This is a type of BIOS used by PCs. + endchoice
config DEBUG_UART_BASE diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index d183eed..1d1f036 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_ALTERA_JTAG_UART) += altera_jtag_uart.o obj-$(CONFIG_ARM_DCC) += arm_dcc.o obj-$(CONFIG_ATMEL_USART) += atmel_usart.o obj-$(CONFIG_DW_SERIAL) += serial_dw.o +obj-$(CONFIG_EFI_APP) += serial_efi.o obj-$(CONFIG_LPC32XX_HSUART) += lpc32xx_hsuart.o obj-$(CONFIG_MCFUART) += mcfuart.o obj-$(CONFIG_OPENCORES_YANU) += opencores_yanu.o diff --git a/drivers/serial/serial_efi.c b/drivers/serial/serial_efi.c new file mode 100644 index 0000000..cf57d89 --- /dev/null +++ b/drivers/serial/serial_efi.c @@ -0,0 +1,157 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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. + */ +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, +};