1 files changed, 426 insertions, 0 deletions
diff --git a/src/target/firmware/board/mediatek/uart.c b/src/target/firmware/board/mediatek/uart.c
new file mode 100644
index 00000000..ff82245e
--- /dev/null
+++ b/src/target/firmware/board/mediatek/uart.c
@@ -0,0 +1,426 @@
+/* MediaTek MT62xx internal UART Driver
+ *
+ * based on the Calypso driver, so there might be some cruft from it left...
+ *
+ * (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010 by Ingo Albrecht <prom@berlin.ccc.de>
+ * (C) 2010 by Steve Markgraf <steve@steve-m.de>
+ * (C) 2011 by Wolfram Sang <wolfram@the-dreams.de>
+ *
+ * All Rights Reserved
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <debug.h>
+#include <memory.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <defines.h>
+#include <uart.h>
+#include <console.h>
+
+#include <comm/sercomm.h>
+
+#include <calypso/irq.h>
+
+/* MT622x */
+#if 0
+#define BASE_ADDR_UART1	0x80130000
+#define BASE_ADDR_UART2	0x80180000
+#define BASE_ADDR_UART3	0x801b0000
+#endif
+
+/* MT 6235 */
+#define BASE_ADDR_UART1	0x81030000
+
+//TODO make UART2 and 3 work
+#define UART_REG(n,m)	(BASE_ADDR_UART1 + (m))
+
+#define LCR7BIT		0x80
+#define LCRBFBIT	0x40
+#define MCR6BIT		0x20
+#define REG_OFFS(m)	((m) & ~(LCR7BIT|LCRBFBIT|MCR6BIT))
+/* read access LCR[7] = 0 */
+enum uart_reg {
+	RBR		= 0x00,
+	IER		= 0x04,
+	IIR		= 0x08,
+	LCR		= 0x0c,
+	MCR		= 0x10,
+	LSR		= 0x14,
+	MSR		= 0x18,
+	SCR		= 0x1c,
+	AUTOBAUD_EN	= 0x20,
+	HIGHSPEED	= 0x24,
+	SAMPLE_COUNT	= 0x28,
+	SAMPLE_POINT	= 0x2c,
+	AUTOBAUD_REG	= 0x30,
+	RATE_FIX_REG	= 0x34, /* undocumented */
+	AUTOBAUDSAMPLE	= 0x38,
+	GUARD		= 0x3c,
+	ESCAPE_DAT	= 0x40,
+	ESCAPE_EN	= 0x44,
+	SLEEP_EN	= 0x48,
+	VFIFO_EN	= 0x4c,
+/* read access LCR[7] = 1 */
+	DLL	= RBR,
+	DLH	= IER,
+/* read/write access LCR[7:0] = 0xbf */
+	EFR	= IIR | LCRBFBIT,
+	XON1	= MCR | LCRBFBIT,
+	XON2	= LSR | LCRBFBIT,
+	XOFF1	= MSR | LCRBFBIT,
+	XOFF2 	= SCR | LCRBFBIT,
+};
+
+enum fcr_bits {
+	FIFO_EN		= (1 << 0),
+	RX_FIFO_CLEAR	= (1 << 1),
+	TX_FIFO_CLEAR	= (1 << 2),
+	DMA_MODE	= (1 << 3),
+};
+#define TX_FIFO_TRIG_SHIFT	4
+#define RX_FIFO_TRIG_SHIFT	6
+
+enum iir_bits {
+	IIR_INT_PENDING			= 0x01,
+	IIR_INT_TYPE			= 0x3E,
+	IIR_INT_TYPE_RX_STATUS_ERROR 	= 0x06,
+	IIR_INT_TYPE_RX_TIMEOUT		= 0x0C,
+	IIR_INT_TYPE_RBR		= 0x04,
+	IIR_INT_TYPE_THR		= 0x02,
+	IIR_INT_TYPE_MSR		= 0x00,
+	IIR_INT_TYPE_XOFF		= 0x10,
+	IIR_INT_TYPE_FLOW		= 0x20,
+	IIR_FCR0_MIRROR			= 0xC0,
+};
+
+
+/* enable or disable the divisor latch for access to DLL, DLH */
+static void uart_set_lcr7bit(int uart, int on)
+{
+	uint8_t reg;
+
+	reg = readb(UART_REG(uart, LCR));
+	if (on)
+		reg |= (1 << 7);
+	else
+		reg &= ~(1 << 7);
+	writeb(reg, UART_REG(uart, LCR));
+}
+
+static uint8_t old_lcr;
+static void uart_set_lcr_bf(int uart, int on)
+{
+	if (on) {
+		old_lcr = readb(UART_REG(uart, LCR));
+		writeb(0xBF, UART_REG(uart, LCR));
+	} else {
+		writeb(old_lcr, UART_REG(uart, LCR));
+	}
+}
+
+/* Enable or disable the TCR_TLR latch bit in MCR[6] */
+static void uart_set_mcr6bit(int uart, int on)
+{
+	uint8_t mcr;
+	/* we assume EFR[4] is always set to 1 */
+	mcr = readb(UART_REG(uart, MCR));
+	if (on)
+		mcr |= (1 << 6);
+	else
+		mcr &= ~(1 << 6);
+	writeb(mcr, UART_REG(uart, MCR));
+}
+
+static void uart_reg_write(int uart, enum uart_reg reg, uint8_t val)
+{
+	if (reg & LCRBFBIT)
+		uart_set_lcr_bf(uart, 1);
+	else if (reg & LCR7BIT)
+		uart_set_lcr7bit(uart, 1);
+	else if (reg & MCR6BIT)
+		uart_set_mcr6bit(uart, 1);
+
+	writeb(val, UART_REG(uart, REG_OFFS(reg)));
+
+	if (reg & LCRBFBIT)
+		uart_set_lcr_bf(uart, 0);
+	else if (reg & LCR7BIT)
+		uart_set_lcr7bit(uart, 0);
+	else if (reg & MCR6BIT)
+		uart_set_mcr6bit(uart, 0);
+}
+
+/* read from a UART register, applying any required latch bits */
+static uint8_t uart_reg_read(int uart, enum uart_reg reg)
+{
+	uint8_t ret;
+
+	if (reg & LCRBFBIT)
+		uart_set_lcr_bf(uart, 1);
+	else if (reg & LCR7BIT)
+		uart_set_lcr7bit(uart, 1);
+	else if (reg & MCR6BIT)
+		uart_set_mcr6bit(uart, 1);
+
+	ret = readb(UART_REG(uart, REG_OFFS(reg)));
+
+	if (reg & LCRBFBIT)
+		uart_set_lcr_bf(uart, 0);
+	else if (reg & LCR7BIT)
+		uart_set_lcr7bit(uart, 0);
+	else if (reg & MCR6BIT)
+		uart_set_mcr6bit(uart, 0);
+
+	return ret;
+}
+
+static void uart_irq_handler_cons(__unused int irqnr)
+{
+	const uint8_t uart = CONS_UART_NR;
+	uint8_t iir;
+
+	//uart_putchar_nb(uart, 'U');
+
+	iir = uart_reg_read(uart, IIR);
+	if (iir & IIR_INT_PENDING)
+		return;
+
+	switch (iir & IIR_INT_TYPE) {
+	case IIR_INT_TYPE_RBR:
+		break;
+	case IIR_INT_TYPE_THR:
+		if (cons_rb_flush() == 1) {
+			/* everything was flushed, disable RBR IRQ */
+			uint8_t ier = uart_reg_read(uart, IER);
+			ier &= ~(1 << 1);
+			uart_reg_write(uart, IER, ier);
+		}
+		break;
+	case IIR_INT_TYPE_MSR:
+		break;
+	case IIR_INT_TYPE_RX_STATUS_ERROR:
+		break;
+	case IIR_INT_TYPE_RX_TIMEOUT:
+		break;
+	case IIR_INT_TYPE_XOFF:
+		break;
+	}
+}
+
+static void uart_irq_handler_sercomm(__unused int irqnr)
+{
+	const uint8_t uart = SERCOMM_UART_NR;
+	uint8_t iir, ch;
+
+	//uart_putchar_nb(uart, 'U');
+
+	iir = uart_reg_read(uart, IIR);
+	if (iir & IIR_INT_PENDING)
+		return;
+
+	switch (iir & IIR_INT_TYPE) {
+	case IIR_INT_TYPE_RX_TIMEOUT:
+	case IIR_INT_TYPE_RBR:
+		/* as long as we have rx data available */
+		while (uart_getchar_nb(uart, &ch)) {
+			if (sercomm_drv_rx_char(ch) < 0) {
+				/* sercomm cannot receive more data right now */
+				uart_irq_enable(uart, UART_IRQ_RX_CHAR, 0);
+			}
+		}
+		break;
+	case IIR_INT_TYPE_THR:
+		/* as long as we have space in the FIFO */
+		while (!uart_tx_busy(uart)) {
+			/* get a byte from sercomm */
+			if (!sercomm_drv_pull(&ch)) {
+				/* no more bytes in sercomm, stop TX interrupts */
+				uart_irq_enable(uart, UART_IRQ_TX_EMPTY, 0);
+				break;
+			}
+			/* write the byte into the TX FIFO */
+			uart_putchar_nb(uart, ch);
+		}
+		break;
+	case IIR_INT_TYPE_MSR:
+		printf("UART IRQ MSR\n");
+		break;
+	case IIR_INT_TYPE_RX_STATUS_ERROR:
+		printf("UART IRQ RX_SE\n");
+		break;
+	case IIR_INT_TYPE_XOFF:
+		printf("UART IRQXOFF\n");
+		break;
+	}
+}
+
+void uart_init(uint8_t uart, __unused uint8_t interrupts)
+{
+	/* no interrupts, only polling so far */
+
+	uart_reg_write(uart, IER, 0x00);
+	if (uart == CONS_UART_NR) {
+		cons_init();
+	} else {
+		sercomm_init();
+		uart_irq_enable(uart, UART_IRQ_RX_CHAR, 1);
+	}
+
+	uart_reg_write(uart, AUTOBAUD_EN, 0x00); /* disable AUTOBAUD */
+	uart_reg_write(uart,   EFR, 0x10); /* Enhanced Features Register */
+
+	/* no XON/XOFF flow control, ENHANCED_EN, no auto-RTS/CTS */
+	uart_reg_write(uart, EFR, (1 << 4));
+	/* enable Tx/Rx FIFO, Tx trigger at 56 spaces, Rx trigger at 60 chars */
+	//FIXME check those FIFO settings
+	uart_reg_write(uart, IIR, FIFO_EN | RX_FIFO_CLEAR | TX_FIFO_CLEAR |
+			(3 << TX_FIFO_TRIG_SHIFT) | (1 << RX_FIFO_TRIG_SHIFT));
+
+	/* RBR interrupt only when TX FIFO and TX shift register are empty */
+	uart_reg_write(uart, SCR, (1 << 0));// | (1 << 3));
+
+	/* 8 bit, 1 stop bit, no parity, no break */
+	uart_reg_write(uart, LCR, 0x03);
+
+	uart_set_lcr7bit(uart, 0);
+}
+
+void uart_poll(uint8_t uart) {
+	if(uart == CONS_UART_NR) {
+		uart_irq_handler_cons(0);
+	} else {
+		uart_irq_handler_sercomm(0);
+	}
+}
+
+void uart_irq_enable(uint8_t uart, enum uart_irq irq, int on)
+{
+	uint8_t ier = uart_reg_read(uart, IER);
+	uint8_t mask = 0;
+
+	switch (irq) {
+	case UART_IRQ_TX_EMPTY:
+		mask = (1 << 1);
+		break;
+	case UART_IRQ_RX_CHAR:
+		mask = (1 << 0);
+		break;
+	}
+
+	if (on)
+		ier |= mask;
+	else
+		ier &= ~mask;
+
+	uart_reg_write(uart, IER, ier);
+}
+
+
+void uart_putchar_wait(uint8_t uart, int c)
+{
+	/* wait while TX FIFO indicates full */
+	while (~readb(UART_REG(uart, LSR)) & 0x20) { }
+
+	/* put character in TX FIFO */
+	writeb(c, UART_REG(uart, RBR));
+}
+
+int uart_putchar_nb(uint8_t uart, int c)
+{
+	/* if TX FIFO indicates full, abort */
+	if (~readb(UART_REG(uart, LSR)) & 0x20)
+		return 0;
+
+	writeb(c, UART_REG(uart, RBR));
+	return 1;
+}
+
+int uart_getchar_nb(uint8_t uart, uint8_t *ch)
+{
+	uint8_t lsr;
+
+	lsr = readb(UART_REG(uart, LSR));
+
+	/* something strange happened */
+	if (lsr & 0x02)
+		printf("LSR RX_OE\n");
+	if (lsr & 0x04)
+		printf("LSR RX_PE\n");
+	if (lsr & 0x08)
+		printf("LSR RX_FE\n");
+	if (lsr & 0x10)
+		printf("LSR RX_BI\n");
+	if (lsr & 0x80)
+		printf("LSR RX_FIFO_STS\n");
+
+	/* is the Rx FIFO empty? */
+	if (!(lsr & 0x01))
+		return 0;
+
+	*ch = readb(UART_REG(uart, RBR));
+	//printf("getchar_nb(%u) = %02x\n", uart, *ch);
+	return 1;
+}
+
+int uart_tx_busy(uint8_t uart)
+{
+	/* Check THRE bit (LSR[5]) to see if FIFO is full */
+	if (~readb(UART_REG(uart, LSR)) & 0x20)
+		return 1;
+	return 0;
+}
+
+#if 0
+/* 26MHz clock input (used when no PLL initialized directly after poweron) */
+static const uint16_t divider[] = {
+	[UART_38400]	= 42,
+	[UART_57600]	= 28,
+	[UART_115200]	= 14,
+	[UART_230400]	= 7,
+	[UART_460800]	= 14,	/* would need UART_REG(HIGHSPEED) = 1 or 2 */
+	[UART_921600]	= 7,	/* would need UART_REG(HIGHSPEED) = 2 */
+};
+#endif
+
+/* 52MHz clock input (after PLL init) */
+static const uint16_t divider[] = {
+	[UART_38400]	= 85,
+	[UART_57600]	= 56,
+	[UART_115200]	= 28,
+	[UART_230400]	= 14,
+	[UART_460800]	= 7,
+	[UART_921600]	= 7,	/* would need UART_REG(HIGHSPEED) = 1 */
+};
+
+int uart_baudrate(uint8_t uart, enum uart_baudrate bdrt)
+{
+	uint16_t div;
+
+	if (bdrt > ARRAY_SIZE(divider))
+		return -1;
+
+	div = divider[bdrt];
+	uart_set_lcr7bit(uart, 1);
+	writeb(div & 0xff, UART_REG(uart, DLL));
+	writeb(div >> 8, UART_REG(uart, DLH));
+	uart_set_lcr7bit(uart, 0);
+
+	return 0;
+}