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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/frv/kernel/gdb-io.c
Initial import
Diffstat (limited to 'arch/frv/kernel/gdb-io.c')
-rw-r--r--arch/frv/kernel/gdb-io.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/frv/kernel/gdb-io.c b/arch/frv/kernel/gdb-io.c
new file mode 100644
index 000000000..0707d3507
--- /dev/null
+++ b/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() */