| /* MN10300 On-chip serial driver for gdbstub I/O |
| * |
| * Copyright (C) 2007 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 Licence |
| * as published by the Free Software Foundation; either version |
| * 2 of the Licence, 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/tty.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/gdb-stub.h> |
| #include <asm/exceptions.h> |
| #include <unit/clock.h> |
| #include "mn10300-serial.h" |
| |
| #if defined(CONFIG_GDBSTUB_ON_TTYSM0) |
| struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif0; |
| #elif defined(CONFIG_GDBSTUB_ON_TTYSM1) |
| struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif1; |
| #else |
| struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif2; |
| #endif |
| |
| |
| /* |
| * initialise the GDB stub I/O routines |
| */ |
| void __init gdbstub_io_init(void) |
| { |
| uint16_t scxctr; |
| int tmp; |
| |
| switch (gdbstub_port->clock_src) { |
| case MNSCx_CLOCK_SRC_IOCLK: |
| gdbstub_port->ioclk = MN10300_IOCLK; |
| break; |
| |
| #ifdef MN10300_IOBCLK |
| case MNSCx_CLOCK_SRC_IOBCLK: |
| gdbstub_port->ioclk = MN10300_IOBCLK; |
| break; |
| #endif |
| default: |
| BUG(); |
| } |
| |
| /* set up the serial port */ |
| gdbstub_io_set_baud(115200); |
| |
| /* we want to get serial receive interrupts */ |
| set_intr_level(gdbstub_port->rx_irq, |
| NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL)); |
| set_intr_level(gdbstub_port->tx_irq, |
| NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL)); |
| set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL), |
| gdbstub_io_rx_handler); |
| |
| *gdbstub_port->rx_icr |= GxICR_ENABLE; |
| tmp = *gdbstub_port->rx_icr; |
| |
| /* enable the device */ |
| scxctr = SC01CTR_CLN_8BIT; /* 1N8 */ |
| switch (gdbstub_port->div_timer) { |
| case MNSCx_DIV_TIMER_16BIT: |
| scxctr |= SC0CTR_CK_TM8UFLOW_8; /* == SC1CTR_CK_TM9UFLOW_8 |
| == SC2CTR_CK_TM10UFLOW_8 */ |
| break; |
| |
| case MNSCx_DIV_TIMER_8BIT: |
| scxctr |= SC0CTR_CK_TM2UFLOW_8; |
| break; |
| } |
| |
| scxctr |= SC01CTR_TXE | SC01CTR_RXE; |
| |
| *gdbstub_port->_control = scxctr; |
| tmp = *gdbstub_port->_control; |
| |
| /* permit level 0 IRQs only */ |
| local_change_intr_mask_level(NUM2EPSW_IM(CONFIG_GDBSTUB_IRQ_LEVEL + 1)); |
| } |
| |
| /* |
| * set up the GDB stub serial port baud rate timers |
| */ |
| void gdbstub_io_set_baud(unsigned baud) |
| { |
| const unsigned bits = 10; /* 1 [start] + 8 [data] + 0 [parity] + |
| * 1 [stop] */ |
| unsigned long ioclk = gdbstub_port->ioclk; |
| unsigned xdiv, tmp; |
| uint16_t tmxbr; |
| uint8_t tmxmd; |
| |
| if (!baud) { |
| baud = 9600; |
| } else if (baud == 134) { |
| baud = 269; /* 134 is really 134.5 */ |
| xdiv = 2; |
| } |
| |
| try_alternative: |
| xdiv = 1; |
| |
| switch (gdbstub_port->div_timer) { |
| case MNSCx_DIV_TIMER_16BIT: |
| tmxmd = TM8MD_SRC_IOCLK; |
| tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 65535) |
| goto timer_okay; |
| |
| tmxmd = TM8MD_SRC_IOCLK_8; |
| tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 65535) |
| goto timer_okay; |
| |
| tmxmd = TM8MD_SRC_IOCLK_32; |
| tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 65535) |
| goto timer_okay; |
| |
| break; |
| |
| case MNSCx_DIV_TIMER_8BIT: |
| tmxmd = TM2MD_SRC_IOCLK; |
| tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 255) |
| goto timer_okay; |
| |
| tmxmd = TM2MD_SRC_IOCLK_8; |
| tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 255) |
| goto timer_okay; |
| |
| tmxmd = TM2MD_SRC_IOCLK_32; |
| tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1; |
| if (tmp > 0 && tmp <= 255) |
| goto timer_okay; |
| break; |
| } |
| |
| /* as a last resort, if the quotient is zero, default to 9600 bps */ |
| baud = 9600; |
| goto try_alternative; |
| |
| timer_okay: |
| gdbstub_port->uart.timeout = (2 * bits * HZ) / baud; |
| gdbstub_port->uart.timeout += HZ / 50; |
| |
| /* set the timer to produce the required baud rate */ |
| switch (gdbstub_port->div_timer) { |
| case MNSCx_DIV_TIMER_16BIT: |
| *gdbstub_port->_tmxmd = 0; |
| *gdbstub_port->_tmxbr = tmxbr; |
| *gdbstub_port->_tmxmd = TM8MD_INIT_COUNTER; |
| *gdbstub_port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE; |
| break; |
| |
| case MNSCx_DIV_TIMER_8BIT: |
| *gdbstub_port->_tmxmd = 0; |
| *(volatile u8 *) gdbstub_port->_tmxbr = (u8)tmxbr; |
| *gdbstub_port->_tmxmd = TM2MD_INIT_COUNTER; |
| *gdbstub_port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE; |
| break; |
| } |
| } |
| |
| /* |
| * wait for a character to come from the debugger |
| */ |
| int gdbstub_io_rx_char(unsigned char *_ch, int nonblock) |
| { |
| unsigned ix; |
| u8 ch, st; |
| #if defined(CONFIG_MN10300_WD_TIMER) |
| int cpu; |
| #endif |
| |
| *_ch = 0xff; |
| |
| if (gdbstub_rx_unget) { |
| *_ch = gdbstub_rx_unget; |
| gdbstub_rx_unget = 0; |
| return 0; |
| } |
| |
| try_again: |
| /* pull chars out of the buffer */ |
| ix = gdbstub_rx_outp; |
| barrier(); |
| if (ix == gdbstub_rx_inp) { |
| if (nonblock) |
| return -EAGAIN; |
| #ifdef CONFIG_MN10300_WD_TIMER |
| for (cpu = 0; cpu < NR_CPUS; cpu++) |
| watchdog_alert_counter[cpu] = 0; |
| #endif |
| goto try_again; |
| } |
| |
| ch = gdbstub_rx_buffer[ix++]; |
| st = gdbstub_rx_buffer[ix++]; |
| barrier(); |
| gdbstub_rx_outp = ix & (PAGE_SIZE - 1); |
| |
| st &= SC01STR_RXF | SC01STR_RBF | SC01STR_FEF | SC01STR_PEF | |
| SC01STR_OEF; |
| |
| /* deal with what we've got |
| * - note that the UART doesn't do BREAK-detection for us |
| */ |
| if (st & SC01STR_FEF && ch == 0) { |
| switch (gdbstub_port->rx_brk) { |
| case 0: gdbstub_port->rx_brk = 1; goto try_again; |
| case 1: gdbstub_port->rx_brk = 2; goto try_again; |
| case 2: |
| gdbstub_port->rx_brk = 3; |
| gdbstub_proto("### GDB MNSERIAL Rx Break Detected" |
| " ###\n"); |
| return -EINTR; |
| default: |
| goto try_again; |
| } |
| } else if (st & SC01STR_FEF) { |
| if (gdbstub_port->rx_brk) |
| goto try_again; |
| |
| gdbstub_proto("### GDB MNSERIAL Framing Error ###\n"); |
| return -EIO; |
| } else if (st & SC01STR_OEF) { |
| if (gdbstub_port->rx_brk) |
| goto try_again; |
| |
| gdbstub_proto("### GDB MNSERIAL Overrun Error ###\n"); |
| return -EIO; |
| } else if (st & SC01STR_PEF) { |
| if (gdbstub_port->rx_brk) |
| goto try_again; |
| |
| gdbstub_proto("### GDB MNSERIAL Parity Error ###\n"); |
| return -EIO; |
| } else { |
| /* look for the tail-end char on a break run */ |
| if (gdbstub_port->rx_brk == 3) { |
| switch (ch) { |
| case 0xFF: |
| case 0xFE: |
| case 0xFC: |
| case 0xF8: |
| case 0xF0: |
| case 0xE0: |
| case 0xC0: |
| case 0x80: |
| case 0x00: |
| gdbstub_port->rx_brk = 0; |
| goto try_again; |
| default: |
| break; |
| } |
| } |
| |
| gdbstub_port->rx_brk = 0; |
| gdbstub_io("### GDB Rx %02x (st=%02x) ###\n", ch, st); |
| *_ch = ch & 0x7f; |
| return 0; |
| } |
| } |
| |
| /* |
| * send a character to the debugger |
| */ |
| void gdbstub_io_tx_char(unsigned char ch) |
| { |
| while (*gdbstub_port->_status & SC01STR_TBF) |
| continue; |
| |
| if (ch == 0x0a) { |
| *(u8 *) gdbstub_port->_txb = 0x0d; |
| while (*gdbstub_port->_status & SC01STR_TBF) |
| continue; |
| } |
| |
| *(u8 *) gdbstub_port->_txb = ch; |
| } |
| |
| /* |
| * flush the transmission buffers |
| */ |
| void gdbstub_io_tx_flush(void) |
| { |
| while (*gdbstub_port->_status & (SC01STR_TBF | SC01STR_TXF)) |
| continue; |
| } |