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Diffstat (limited to 'gdb/arc-gpio.c')
| -rw-r--r-- | gdb/arc-gpio.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/gdb/arc-gpio.c b/gdb/arc-gpio.c new file mode 100644 index 0000000..cc9f775 --- /dev/null +++ b/gdb/arc-gpio.c @@ -0,0 +1,251 @@ +/* Target dependent code for ARC processor family, for GDB, the GNU debugger. + + Copyright 2005, 2008, 2009 Free Software Foundation, Inc. + + Contributed by ARC International (www.arc.com) + + Authors: + Richard Stuckey <richard.stuckey@arc.com> + A.N. Other <unknown> + + This file is part of GDB. + + 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 3 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, see <http://www.gnu.org/licenses/>. */ + +/******************************************************************************/ +/* */ +/* Outline: */ +/* This module implements operations for reading data from / writing data */ +/* to a parallel port using a GPIO (General Purpose Input/Output) driver. */ +/* */ +/******************************************************************************/ + +/* system header files */ +#include <string.h> +#include <sys/ioctl.h> +#include <fcntl.h> +#include <errno.h> + +/* gdb header files */ +#include "defs.h" + +/* ARC header files */ +#include "arc-gpio.h" + + +/* -------------------------------------------------------------------------- */ +/* local data */ +/* -------------------------------------------------------------------------- */ + +// I/O control numbers. + +// Linux kernel uses 0x54XX for special purposes. Avoid such. +// We'll pick large numbers. +// We don't use the linux convention of dividing the IOC into a bunch +// of bit fields. We can always switch to this later, as the +// IOC 0 returns the driver version (which IOC value will never change). + +#define GPIO_IOC_VERSION 0 // returns version +#define GPIO_IOC_BASE 0xaa3a0000UL // Intended for use on ARCangel 3! + + +// Switch base address of parallel port. 0x3f8 is assumed. +// WARNING! You can write on any port whatsoever with this driver. +// BE CAREFUL! +#define GPIO_IOC_SET_PORT_BASE (GPIO_IOC_BASE + 1) // cmd, arg=port base + +// General input/output ioctl. See GPIO_ioctl struct. +#define GPIO_IOC_DO_IO (GPIO_IOC_BASE + 2) // cmd, arg=GPIO_ioctl * + +// For emergency purposes in case the driver is goofed up. +#define GPIO_IOC_HARD_RESET (GPIO_IOC_BASE + 3) // cmd, no arg + +// Do you have an antiquated parallel port? You might need to ask +// the driver to use outb_p and inb_p (_p = pause). Default is not to. +#define GPIO_IOC_SET_PAUSE (GPIO_IOC_BASE + 4) // arg = 1 => use pause; otherwise not. + + +/* parallel port I/O addresses (LPT1) */ +#define PORT_BASE_ADDRESS 0x378 +#define DATA_PORT_ADDRESS (PORT_BASE_ADDRESS + DATA_PORT) +#define STATUS_PORT_ADDRESS (PORT_BASE_ADDRESS + STATUS_PORT) +#define CONTROL_PORT_ADDRESS (PORT_BASE_ADDRESS + CONTROL_PORT) + +#define NULL_FILE_DESCRIPTOR (-1) + + +typedef struct +{ + // This is used for general input and output in the same ioctl. + // N.B. "input" is input TO the port, and "output" is output FROM the port. + // + // inlen is always even and represents a number of pairs: + // + // [0|1|2, value] : write value to port_base+0|1|2. + // [0x80|0x81|0x82, <ignored>] : read value from port_base+0|1|2 + // and append result to outbuf. + // + // Thus one can intermix read and write in the same ioctl. + + // inlen is replaced by the number of input bytes consumed. + unsigned inlen; + char *inbuf; + + // outlen is replaced by the number of output bytes written. + unsigned outlen; + char *outbuf; +} GPIO_ioctl; + + +/* Buffers to hold data read from / written to ports; we generally read/write + only 1 byte of data at a time, so the buffers need hold only 1 byte pair each. */ +static char input_buffer [2]; +static char output_buffer[2]; +static GPIO_ioctl ioctl_data = { 0, input_buffer, 0, output_buffer }; + +/* A file descriptor for the GPIO driver. */ +static int gpio_driver = NULL_FILE_DESCRIPTOR; + +/* Debug data. */ +// static const char name[] = {'D', 'S', 'C'}; + + +/* -------------------------------------------------------------------------- */ +/* externally visible data */ +/* -------------------------------------------------------------------------- */ + +/* This is set to TRUE if an I/O error occurs in accessing the port. */ +Boolean gpio_port_error; + + +/* -------------------------------------------------------------------------- */ +/* externally visible functions */ +/* -------------------------------------------------------------------------- */ + +/* Initialization of the GPIO interface. */ + +Boolean +gpio_open (void) +{ + /* Open the driver, if not already open. */ + if (gpio_driver == NULL_FILE_DESCRIPTOR) + { + gpio_driver = open(GPIO_DEVICE, O_RDWR); + + if ((gpio_driver == NULL_FILE_DESCRIPTOR) || + ioctl(gpio_driver, GPIO_IOC_HARD_RESET) || + ioctl(gpio_driver, GPIO_IOC_SET_PORT_BASE, PORT_BASE_ADDRESS)) + { + warning(_("unable to open JTAG port (device " GPIO_DEVICE "): %s"), + strerror(errno)); + return FALSE; + } + + gpio_port_error = FALSE; + } + + return TRUE; +} + + +/* Close the GPIO interface. */ + +void +gpio_close (void) +{ + /* Close the driver, if not already closed. */ + if (gpio_driver != NULL_FILE_DESCRIPTOR) + { + /* Close file descriptor opened for communication with gpio driver. */ + if (close(gpio_driver) == -1) + warning(_("unable to close JTAG port (device " GPIO_DEVICE "): %s"), + strerror(errno)); + + gpio_driver = NULL_FILE_DESCRIPTOR; + } +} + + +/* Write a byte of data to the given port. */ + +void +gpio_write (ParallelPort port, Byte data) +{ + ioctl_data.inlen = 2; + ioctl_data.inbuf[0] = (char) port; + ioctl_data.inbuf[1] = (char) data; + + if (ioctl(gpio_driver, GPIO_IOC_DO_IO, &ioctl_data)) + error(_("Failure writing to port %d: %s"), port, strerror(errno)); + + /* If no data has been consumed by the port. */ + if (ioctl_data.inlen == 0) + gpio_port_error = TRUE; + +// DEBUG("ioctl_data.inlen: %d\n", ioctl_data.inlen); +// DEBUG("GPIO write: %02x -> %c\n", data, name[port]); +} + + +/* Read a byte of data from the given port. */ + +Byte +gpio_read (ParallelPort port) +{ + ioctl_data.inlen = 2; + ioctl_data.inbuf[0] = (char) (port + 0x80); +// ioctl_data.inbuf[1] is ignored + + /* N.B. outlen must be set! */ + ioctl_data.outlen = 1; + ioctl_data.outbuf[0] = (char) 0; // in case the read fails + + if (ioctl(gpio_driver, GPIO_IOC_DO_IO, &ioctl_data)) + error(_("Failure reading from port %d: %s"), port, strerror(errno)); + + /* If no data has been provided by the port */ + if (ioctl_data.outlen == 0) + gpio_port_error = TRUE; + +// DEBUG("ioctl_data.outlen: %d\n", ioctl_data.outlen); +// DEBUG("GPIO read : %02x <- %c\n", (Byte) ioctl_data.outbuf[0], name[port]); + + return (Byte) ioctl_data.outbuf[0]; +} + + +/* Write a series of bytes of data to the ports. */ + +void +gpio_write_array (GPIO_Pair array[], unsigned int num_elements) +{ + char buffer[num_elements * 2]; + GPIO_ioctl data = { 0, buffer, 0, NULL }; + unsigned int i; + + for (i = 0; i < num_elements; i++) + { + buffer[data.inlen++] = (char) array[i].port; + buffer[data.inlen++] = (char) array[i].data; + } + + if (ioctl(gpio_driver, GPIO_IOC_DO_IO, &data)) + error(_("Failure writing to port: %s"), strerror(errno)); + + /* If no data has been consumed by the port. */ + if (ioctl_data.inlen == 0) + gpio_port_error = TRUE; +} + +/******************************************************************************/ |