libpayload: Remove redundant 8250 MMIO32 UART driver

The more generic 8250 driver can handle both port-mapped and memory-
mapped 8250-compatible UARTs, with different register sizes. Thus, a
separate driver for MMIO32 is not needed.
The generic 8250 driver was tested to work for both output and input,
on Apollolake SoC, which only presents an MMIO32 UART.

Change-Id: Idab766588ddd097649a37de92394b0078ecc660a
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: https://review.coreboot.org/12524
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

3 files changed, 2 insertions, 122 deletions

diff --git a/payloads/libpayload/Kconfig b/payloads/libpayload/Kconfig
index 024fa1502b..5e0262426b 100644
--- a/payloads/libpayload/Kconfig
+++ b/payloads/libpayload/Kconfig
@@ -200,21 +200,15 @@ config SERIAL_CONSOLE
 	default y
 
 config 8250_SERIAL_CONSOLE
-	bool "8250, 16450, 16550, 16550A compatible serial port driver"
+	bool "8250-compatible serial port driver (including IO and MMIO)"
 	depends on SERIAL_CONSOLE
-	default y if ARCH_X86
-	default n if !ARCH_X86
+	default y
 
 config S5P_SERIAL_CONSOLE
 	bool "Exynos SOC, S5P compatible serial port driver"
 	depends on SERIAL_CONSOLE
 	default n
 
-config 8250_MMIO32_SERIAL_CONSOLE
-	bool "Memory-mapped 8250-compatible serial port driver with 32-bit regs"
-	depends on SERIAL_CONSOLE
-	default n
-
 config IPQ806X_SERIAL_CONSOLE
 	bool "IPQ806x SOC compatible serial port driver"
 	depends on SERIAL_CONSOLE
diff --git a/payloads/libpayload/drivers/Makefile.inc b/payloads/libpayload/drivers/Makefile.inc
index 083f122ab8..be43b350c2 100644
--- a/payloads/libpayload/drivers/Makefile.inc
+++ b/payloads/libpayload/drivers/Makefile.inc
@@ -35,7 +35,6 @@ libc-$(CONFIG_LP_SPEAKER) += speaker.c
 
 libc-$(CONFIG_LP_8250_SERIAL_CONSOLE) += serial/8250.c
 libc-$(CONFIG_LP_S5P_SERIAL_CONSOLE) += serial/s5p.c
-libc-$(CONFIG_LP_8250_MMIO32_SERIAL_CONSOLE) += serial/8250_mmio32.c
 libc-$(CONFIG_LP_IPQ806X_SERIAL_CONSOLE) += serial/ipq806x.c
 libc-$(CONFIG_LP_BG4CD_SERIAL_CONSOLE) += serial/bg4cd.c
 libc-$(CONFIG_LP_PC_KEYBOARD) += keyboard.c
diff --git a/payloads/libpayload/drivers/serial/8250_mmio32.c b/payloads/libpayload/drivers/serial/8250_mmio32.c
deleted file mode 100644
index 285f7f6dac..0000000000
--- a/payloads/libpayload/drivers/serial/8250_mmio32.c
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright 2013 Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <libpayload.h>
-#include <stdint.h>
-
-struct mmio32_uart {
-	union {
-		uint32_t thr; // Transmit holding register.
-		uint32_t rbr; // Receive buffer register.
-		uint32_t dll; // Divisor latch lsb.
-	};
-	union {
-		uint32_t ier; // Interrupt enable register.
-		uint32_t dlm; // Divisor latch msb.
-	};
-	union {
-		uint32_t iir; // Interrupt identification register.
-		uint32_t fcr; // FIFO control register.
-	};
-	uint32_t lcr; // Line control register.
-	uint32_t mcr; // Modem control register.
-	uint32_t lsr; // Line status register.
-	uint32_t msr; // Modem status register.
-} __attribute__ ((packed));
-
-enum {
-	LSR_DR = 0x1 << 0, // Data ready.
-	LSR_OE = 0x1 << 1, // Overrun.
-	LSR_PE = 0x1 << 2, // Parity error.
-	LSR_FE = 0x1 << 3, // Framing error.
-	LSR_BI = 0x1 << 4, // Break.
-	LSR_THRE = 0x1 << 5, // Xmit holding register empty.
-	LSR_TEMT = 0x1 << 6, // Xmitter empty.
-	LSR_ERR = 0x1 << 7 // Error.
-};
-
-static struct mmio32_uart *uart = NULL;
-
-void serial_putchar(unsigned int c)
-{
-	while (!(readl(&uart->lsr) & LSR_THRE))
-		/* wait for transmit register to clear */;
-
-	writel((char)c, &uart->thr);
-	if (c == '\n')
-		serial_putchar('\r');
-}
-
-int serial_havechar(void)
-{
-	uint8_t lsr = readl(&uart->lsr);
-	return (lsr & LSR_DR) == LSR_DR;
-}
-
-int serial_getchar(void)
-{
-	while (!serial_havechar())
-		/* wait for character */;
-
-	return readl(&uart->rbr);
-}
-
-static struct console_output_driver mmio32_serial_output = {
-	.putchar = &serial_putchar
-};
-
-static struct console_input_driver mmio32_serial_input = {
-	.havekey = &serial_havechar,
-	.getchar = &serial_getchar
-};
-
-void serial_init(void)
-{
-	if (!lib_sysinfo.serial || !lib_sysinfo.serial->baseaddr)
-		return;
-
-	uart = (struct mmio32_uart *)(uintptr_t)lib_sysinfo.serial->baseaddr;
-}
-
-void serial_console_init(void)
-{
-	serial_init();
-
-	if (uart) {
-		console_add_output_driver(&mmio32_serial_output);
-		console_add_input_driver(&mmio32_serial_input);
-	}
-}