soc/marvell/armada38x: Add generic support for armada38x

Skeleton for soc armada38x

BUG=chrome-os-partner:47462
TEST=None
BRANCH=tot

Change-Id: I76f631ee6cdfc90c44727cb20aa960796bc785a5
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: e91cc19468325f005c6ac920bbe27a174c409727
Original-Change-Id: Iac5fc34df1ba18b4515029aa2fcff8f78a5df191
Original-Signed-off-by: Ruilin Hao <rlhao@marvell.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/313179
Original-Commit-Ready: Kan Yan <kyan@google.com>
Original-Tested-by: Kan Yan <kyan@google.com>
Original-Reviewed-by: Kan Yan <kyan@google.com>
Reviewed-on: https://review.coreboot.org/13110
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/soc/marvell/armada38x/uart.c

@@ -0,0 +1,151 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/io.h>
+#include <console/uart.h>
+#include <console/console.h>
+#include <drivers/uart/uart8250reg.h>
+#include <boot/coreboot_tables.h>
+#include <stdint.h>
+#include <assert.h>
+#include <soc/common.h>
+
+struct armada38x_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));
+
+static void armada38x_uart_tx_flush(struct armada38x_uart *uart_ptr);
+static int armada38x_uart_tst_byte(struct armada38x_uart *uart_ptr);
+
+static void armada38x_uart_init(struct armada38x_uart *uart_ptr)
+{
+	const uint8_t line_config = UART8250_LCR_WLS_8;
+	uint16_t divisor = (u16) uart_baudrate_divisor(default_baudrate(),
+		uart_platform_refclk(), 16);
+
+	armada38x_uart_tx_flush(uart_ptr);
+	// Disable interrupts.
+	write8(&uart_ptr->ier, 0);
+	// Enable access to divisor latches.
+	write8(&uart_ptr->lcr, UART8250_LCR_DLAB);
+	// Set the divisor.
+	write8(&uart_ptr->dll, divisor & 0xff);
+	write8(&uart_ptr->dlm, (divisor >> 8) & 0xff);
+	// Hide divisor latches and program line config.
+	write8(&uart_ptr->lcr, line_config);
+	// Enable FIFOs, and clear receive and transmit.
+	write8(&uart_ptr->fcr, UART8250_FCR_FIFO_EN | UART8250_FCR_CLEAR_RCVR |
+				   UART8250_FCR_CLEAR_XMIT);
+}
+
+static void armada38x_uart_tx_byte(struct armada38x_uart *uart_ptr,
+					unsigned char data)
+{
+	while (!(read8(&uart_ptr->lsr) & UART8250_LSR_THRE))
+		;
+	write8(&uart_ptr->thr, data);
+}
+
+static void armada38x_uart_tx_flush(struct armada38x_uart *uart_ptr)
+{
+	while (!(read8(&uart_ptr->lsr) & UART8250_LSR_TEMT))
+		;
+}
+
+static unsigned char armada38x_uart_rx_byte(struct armada38x_uart *uart_ptr)
+{
+	if (!armada38x_uart_tst_byte(uart_ptr))
+		return 0;
+	return read8(&uart_ptr->rbr);
+}
+
+static int armada38x_uart_tst_byte(struct armada38x_uart *uart_ptr)
+{
+	return (read8(&uart_ptr->lsr) & UART8250_LSR_DR) == UART8250_LSR_DR;
+}
+
+unsigned int uart_platform_refclk(void)
+{
+	return MV_BOARD_TCLK_250MHZ;
+}
+
+uintptr_t uart_platform_base(int idx)
+{
+	/* Default to UART 0 */
+	unsigned int base = CONFIG_CONSOLE_SERIAL_UART_ADDRESS;
+
+	assert((idx >= 0) && (idx < 2));
+	base += idx * 0x100;
+	return base;
+}
+
+void uart_init(int idx)
+{
+	struct armada38x_uart *uart_ptr = uart_platform_baseptr(idx);
+
+	armada38x_uart_init(uart_ptr);
+}
+
+void uart_tx_byte(int idx, unsigned char data)
+{
+	struct armada38x_uart *uart_ptr = uart_platform_baseptr(idx);
+
+	armada38x_uart_tx_byte(uart_ptr, data);
+}
+
+void uart_tx_flush(int idx)
+{
+	struct armada38x_uart *uart_ptr = uart_platform_baseptr(idx);
+
+	armada38x_uart_tx_flush(uart_ptr);
+}
+
+unsigned char uart_rx_byte(int idx)
+{
+	struct armada38x_uart *uart_ptr = uart_platform_baseptr(idx);
+
+	return armada38x_uart_rx_byte(uart_ptr);
+}
+
+#if ENV_RAMSTAGE
+void uart_fill_lb(void *data)
+{
+	struct lb_serial serial;
+
+	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
+	serial.baseaddr = uart_platform_base(CONFIG_UART_FOR_CONSOLE);
+	serial.baud = default_baudrate();
+	serial.regwidth = 1;
+	lb_add_serial(&serial, data);
+
+	lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
+}
+#endif