From 275854baeeec02e37c8f8bf718f94090f2a531ff Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 4 Aug 2015 12:33:40 -0600 Subject: efi: Add a serial driver Add a serial driver which makes use of EFI's console in/out service. Signed-off-by: Simon Glass Reviewed-by: Bin Meng Tested on Intel Crown Bay and QEMU Tested-by: Bin Meng --- drivers/serial/serial_efi.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 drivers/serial/serial_efi.c (limited to 'drivers/serial/serial_efi.c') diff --git a/drivers/serial/serial_efi.c b/drivers/serial/serial_efi.c new file mode 100644 index 00000000000..cf57d8977b5 --- /dev/null +++ b/drivers/serial/serial_efi.c @@ -0,0 +1,157 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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, +}; -- cgit v1.2.3