efi: Add a serial driver

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>

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 078246d22fa42131b481e08f1e0940b74d9e15d7..b5a91b707ed72374d7ebf3a0beb9f6f31379a006 100644 (file)
--- 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 d183eedbcb3f8598c82968092c6bf493208b1f23..1d1f0361cd71a40bf0585a0a2216945a977cdc68 100644 (file)
--- 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 (file)
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,
+};