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 078246d..b5a91b7 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -44,6 +44,15 @@
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-$(CONFIG_ARM_DCC) += arm_dcc.o
obj-$(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,
+};