mediatek: Move uart, timer and cbmem code to a common directory.

This patch moves uart, timer and cbmem code which can be reused into a
common directory under soc/mediatek.

BUG=b:80501386
BRANCH=none
TEST=the refactored code works fine on the new platform (with the rest
     of the patches applied) and Elm platform

Change-Id: I5210149b324947ee90f1a481b42f0e2e1f7cfc25
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/26658
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

1 files changed, 188 insertions, 0 deletions

diff --git a/src/soc/mediatek/common/uart.c b/src/soc/mediatek/common/uart.c
new file mode 100644
index 0000000000..cfc469bed6
--- /dev/null
+++ b/src/soc/mediatek/common/uart.c
@@ -0,0 +1,188 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 MediaTek 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 <boot/coreboot_tables.h>
+#include <console/console.h>	/* for __console definition */
+#include <console/uart.h>
+#include <drivers/uart/uart8250reg.h>
+#include <stdint.h>
+#include <compiler.h>
+
+#include <soc/addressmap.h>
+
+struct mtk_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 efr;	/* Enhanced feature register. */
+	};
+	uint32_t lcr;		/* Line control register. */
+	union {
+		uint32_t mcr;	/* Modem control register. */
+		uint32_t xn1;	/* XON1 */
+	};
+	union {
+		uint32_t lsr;	/* Line status register. */
+		uint32_t xn2;	/* XON2 */
+	};
+	union {
+		uint32_t msr;	/* Modem status register. */
+		uint32_t xf1;	/* XOFF1 */
+	};
+	union {
+		uint32_t scr;	/* Scratch register. */
+		uint32_t xf2;	/* XOFF2 */
+	};
+	uint32_t autobaud_en;	/* Enable auto baudrate. */
+	uint32_t highspeed;	/* High speed UART. */
+} __packed;
+
+/* Peripheral Reset and Power Down registers */
+struct mtk_peri_globalcon {
+	uint32_t rst0;
+	uint32_t rst1;
+	uint32_t pdn0_set;
+	uint32_t pdn1_set;
+	uint32_t pdn0_clr;
+	uint32_t pdn1_clr;
+	uint32_t pdn0_sta;
+	uint32_t pdn1_sta;
+	uint32_t pdn_md1_set;
+	uint32_t pdn_md2_set;
+	uint32_t pdn_md1_clr;
+	uint32_t pdn_md2_clr;
+	uint32_t pdn_md1_sta;
+	uint32_t pdn_md2_sta;
+	uint32_t pdn_md_mask;
+} __packed;
+
+static struct mtk_uart *const uart_ptr = (void *)UART0_BASE;
+
+static void mtk_uart_tx_flush(void);
+static int mtk_uart_tst_byte(void);
+
+static void mtk_uart_init(void)
+{
+	/* Use a hardcoded divisor for now. */
+	const unsigned int uartclk = 26 * MHz;
+	const unsigned int baudrate = get_uart_baudrate();
+	const uint8_t line_config = UART8250_LCR_WLS_8;  /* 8n1 */
+	unsigned int highspeed, quot, divisor, remainder;
+
+	if (baudrate <= 115200) {
+		highspeed = 0;
+		quot = 16;
+	} else {
+		highspeed = 2;
+		quot = 4;
+	}
+
+	/* Set divisor DLL and DLH  */
+	divisor = uartclk / (quot * baudrate);
+	remainder = uartclk % (quot * baudrate);
+
+	if (remainder >= (quot / 2) * baudrate)
+		divisor += 1;
+
+	mtk_uart_tx_flush();
+
+	/* Disable interrupts. */
+	write8(&uart_ptr->ier, 0);
+	/* Force DTR and RTS to high. */
+	write8(&uart_ptr->mcr, UART8250_MCR_DTR | UART8250_MCR_RTS);
+	/* Set High speed UART register. */
+	write8(&uart_ptr->highspeed, highspeed);
+	/* Set line configuration, access divisor latches. */
+	write8(&uart_ptr->lcr, UART8250_LCR_DLAB | line_config);
+	/* Set the divisor. */
+	write8(&uart_ptr->dll, divisor & 0xff);
+	write8(&uart_ptr->dlm, (divisor >> 8) & 0xff);
+	/* Hide the divisor latches. */
+	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 mtk_uart_tx_byte(unsigned char data)
+{
+	while (!(read8(&uart_ptr->lsr) & UART8250_LSR_THRE))
+		;
+	write8(&uart_ptr->thr, data);
+}
+
+static void mtk_uart_tx_flush(void)
+{
+	while (!(read8(&uart_ptr->lsr) & UART8250_LSR_TEMT))
+		;
+}
+
+static unsigned char mtk_uart_rx_byte(void)
+{
+	if (!mtk_uart_tst_byte())
+		return 0;
+	return read8(&uart_ptr->rbr);
+}
+
+static int mtk_uart_tst_byte(void)
+{
+	return (read8(&uart_ptr->lsr) & UART8250_LSR_DR) == UART8250_LSR_DR;
+}
+
+void uart_init(int idx)
+{
+	mtk_uart_init();
+}
+
+unsigned char uart_rx_byte(int idx)
+{
+	return mtk_uart_rx_byte();
+}
+
+void uart_tx_byte(int idx, unsigned char data)
+{
+	mtk_uart_tx_byte(data);
+}
+
+void uart_tx_flush(int idx)
+{
+	mtk_uart_tx_flush();
+}
+
+#ifndef __PRE_RAM__
+void uart_fill_lb(void *data)
+{
+	struct lb_serial serial;
+	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
+	serial.baseaddr = UART0_BASE;
+	serial.baud = get_uart_baudrate();
+	serial.regwidth = 4;
+	lb_add_serial(&serial, data);
+
+	lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
+}
+#endif