Fixed MTP to work with TWRP

arch/frv/kernel/gdb-io.c

@@ -0,0 +1,215 @@
+/* gdb-io.c: FR403 GDB stub I/O
+ *
+ * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * 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.
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_reg.h>
+
+#include <asm/pgtable.h>
+#include <asm/irc-regs.h>
+#include <asm/timer-regs.h>
+#include <asm/gdb-stub.h>
+#include "gdb-io.h"
+
+#ifdef CONFIG_GDBSTUB_UART0
+#define __UART(X) (*(volatile uint8_t *)(UART0_BASE + (UART_##X)))
+#define __UART_IRR_NMI 0xff0f0000
+#else /* CONFIG_GDBSTUB_UART1 */
+#define __UART(X) (*(volatile uint8_t *)(UART1_BASE + (UART_##X)))
+#define __UART_IRR_NMI 0xfff00000
+#endif
+
+#define LSR_WAIT_FOR(STATE)			\
+do {						\
+	gdbstub_do_rx();			\
+} while (!(__UART(LSR) & UART_LSR_##STATE))
+
+#define FLOWCTL_QUERY(LINE)	({ __UART(MSR) & UART_MSR_##LINE; })
+#define FLOWCTL_CLEAR(LINE)	do { __UART(MCR) &= ~UART_MCR_##LINE; mb(); } while (0)
+#define FLOWCTL_SET(LINE)	do { __UART(MCR) |= UART_MCR_##LINE;  mb(); } while (0)
+
+#define FLOWCTL_WAIT_FOR(LINE)			\
+do {						\
+	gdbstub_do_rx();			\
+} while(!FLOWCTL_QUERY(LINE))
+
+/*****************************************************************************/
+/*
+ * initialise the GDB stub
+ * - called with PSR.ET==0, so can't incur external interrupts
+ */
+void gdbstub_io_init(void)
+{
+	/* set up the serial port */
+	__UART(LCR) = UART_LCR_WLEN8; /* 1N8 */
+	__UART(FCR) =
+		UART_FCR_ENABLE_FIFO |
+		UART_FCR_CLEAR_RCVR |
+		UART_FCR_CLEAR_XMIT |
+		UART_FCR_TRIGGER_1;
+
+	FLOWCTL_CLEAR(DTR);
+	FLOWCTL_SET(RTS);
+
+//	gdbstub_set_baud(115200);
+
+	/* we want to get serial receive interrupts */
+	__UART(IER) = UART_IER_RDI | UART_IER_RLSI;
+	mb();
+
+	__set_IRR(6, __UART_IRR_NMI);	/* map ERRs and UARTx to NMI */
+
+} /* end gdbstub_io_init() */
+
+/*****************************************************************************/
+/*
+ * set up the GDB stub serial port baud rate timers
+ */
+void gdbstub_set_baud(unsigned baud)
+{
+	unsigned value, high, low;
+	u8 lcr;
+
+	/* work out the divisor to give us the nearest higher baud rate */
+	value = __serial_clock_speed_HZ / 16 / baud;
+
+	/* determine the baud rate range */
+	high = __serial_clock_speed_HZ / 16 / value;
+	low = __serial_clock_speed_HZ / 16 / (value + 1);
+
+	/* pick the nearest bound */
+	if (low + (high - low) / 2 > baud)
+		value++;
+
+	lcr = __UART(LCR);
+	__UART(LCR) |= UART_LCR_DLAB;
+	mb();
+	__UART(DLL) = value & 0xff;
+	__UART(DLM) = (value >> 8) & 0xff;
+	mb();
+	__UART(LCR) = lcr;
+	mb();
+
+} /* end gdbstub_set_baud() */
+
+/*****************************************************************************/
+/*
+ * receive characters into the receive FIFO
+ */
+void gdbstub_do_rx(void)
+{
+	unsigned ix, nix;
+
+	ix = gdbstub_rx_inp;
+
+	while (__UART(LSR) & UART_LSR_DR) {
+		nix = (ix + 2) & 0xfff;
+		if (nix == gdbstub_rx_outp)
+			break;
+
+		gdbstub_rx_buffer[ix++] = __UART(LSR);
+		gdbstub_rx_buffer[ix++] = __UART(RX);
+		ix = nix;
+	}
+
+	gdbstub_rx_inp = ix;
+
+	__clr_RC(15);
+	__clr_IRL();
+
+} /* end gdbstub_do_rx() */
+
+/*****************************************************************************/
+/*
+ * wait for a character to come from the debugger
+ */
+int gdbstub_rx_char(unsigned char *_ch, int nonblock)
+{
+	unsigned ix;
+	u8 ch, st;
+
+	*_ch = 0xff;
+
+	if (gdbstub_rx_unget) {
+		*_ch = gdbstub_rx_unget;
+		gdbstub_rx_unget = 0;
+		return 0;
+	}
+
+ try_again:
+	gdbstub_do_rx();
+
+	/* pull chars out of the buffer */
+	ix = gdbstub_rx_outp;
+	if (ix == gdbstub_rx_inp) {
+		if (nonblock)
+			return -EAGAIN;
+		//watchdog_alert_counter = 0;
+		goto try_again;
+	}
+
+	st = gdbstub_rx_buffer[ix++];
+	ch = gdbstub_rx_buffer[ix++];
+	gdbstub_rx_outp = ix & 0x00000fff;
+
+	if (st & UART_LSR_BI) {
+		gdbstub_proto("### GDB Rx Break Detected ###\n");
+		return -EINTR;
+	}
+	else if (st & (UART_LSR_FE|UART_LSR_OE|UART_LSR_PE)) {
+		gdbstub_io("### GDB Rx Error (st=%02x) ###\n",st);
+		return -EIO;
+	}
+	else {
+		gdbstub_io("### GDB Rx %02x (st=%02x) ###\n",ch,st);
+		*_ch = ch & 0x7f;
+		return 0;
+	}
+
+} /* end gdbstub_rx_char() */
+
+/*****************************************************************************/
+/*
+ * send a character to the debugger
+ */
+void gdbstub_tx_char(unsigned char ch)
+{
+	FLOWCTL_SET(DTR);
+	LSR_WAIT_FOR(THRE);
+//	FLOWCTL_WAIT_FOR(CTS);
+
+	if (ch == 0x0a) {
+		__UART(TX) = 0x0d;
+		mb();
+		LSR_WAIT_FOR(THRE);
+//		FLOWCTL_WAIT_FOR(CTS);
+	}
+	__UART(TX) = ch;
+	mb();
+
+	FLOWCTL_CLEAR(DTR);
+} /* end gdbstub_tx_char() */
+
+/*****************************************************************************/
+/*
+ * send a character to the debugger
+ */
+void gdbstub_tx_flush(void)
+{
+	LSR_WAIT_FOR(TEMT);
+	LSR_WAIT_FOR(THRE);
+	FLOWCTL_CLEAR(DTR);
+} /* end gdbstub_tx_flush() */