| /* 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; |
| } |
| |
| /******************************************************************************/ |
