--- Begin Message ---
Author: werner
Date: 2008-02-22 13:01:09 +0100 (Fri, 22 Feb 2008)
New Revision: 4102
Added:
trunk/src/target/gpio/
trunk/src/target/gpio/Makefile
trunk/src/target/gpio/README
trunk/src/target/gpio/gpio.c
Log:
GPIO is a utility to read and set GPIO pins of the Samsung S3C2442 MCU.
Added: trunk/src/target/gpio/Makefile
===================================================================
--- trunk/src/target/gpio/Makefile 2008-02-21 11:41:29 UTC (rev 4101)
+++ trunk/src/target/gpio/Makefile 2008-02-22 12:01:09 UTC (rev 4102)
@@ -0,0 +1,5 @@
+CC=arm-angstrom-linux-gnueabi-gcc
+
+CFLAGS=-Wall -g
+
+all: gpio
Added: trunk/src/target/gpio/README
===================================================================
--- trunk/src/target/gpio/README 2008-02-21 11:41:29 UTC (rev 4101)
+++ trunk/src/target/gpio/README 2008-02-22 12:01:09 UTC (rev 4102)
@@ -0,0 +1,87 @@
+gpio - Read and set GPIO pins (of the Samsung S3C2442 MCU)
+==========================================================
+
+Copyright (C) 2008 by OpenMoko, Inc.
+Written by Werner Almesberger <[EMAIL PROTECTED]>
+All Rights Reserved
+
+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.
+
+
+Displaying all GPIOs
+--------------------
+
+# gpio
+
+If invoked without arguments, "gpio" displays the state of all GPIO
+pins of the MCU. The state is represented as follows:
+
+ 0 Input, reads 0
+ 1 Input, reads 1
+ >0 Output, reads 0 (1)
+ >1 Output, reads 1 (1)
+ F0 Function, reads 0 (2)
+ F1 Function, reads 1 (2)
+ X0 Secondary function or reserved, reads 0 (2)
+ X1 Idem, reads 1 (2)
+
+(1) The value read back from a port pin reflects the voltage level on
+ that pin. For an output, this is normally the value that we try to
+ output. However, if the pin is externally forced high or low, the
+ value read back may be different from the value we try to output.
+
+(2) According to Samsung documentation, the value read back from a
+ function pin is undefined. However, it usually represents the real
+ state of that pin.
+
+The pin state can be followed by "R", which indicates that the
+corresponding pull-down resistor is active.
+
+Changes in the GPIO settings can be monitored by running "gpio" under
+"watch", e.g., with
+
+# watch -n 1 -d ./gpio
+
+
+Displaying individual GPIOs
+---------------------------
+
+Individual GPIOs can be displayed by specifying their names on the command
+line, e.g.,
+
+# gpio b0 b1 b2
+
+Names are case-insensitive. The GPIO's state is displayed as described
+above.
+
+
+Setting GPIOs
+-------------
+
+A GPIO can be set by specifying an assignment on the command line, as
+follows:
+
+# gpio gpio=value
+
+The GPIO is specified in the same way as when displaying individual
+GPIOs. The following values can be set:
+
+ 0 Output 0
+ 1 Output 1
+ Z Input
+ F Function
+ X Secondary function
+
+In addition to this, the value can be followed by "R" to set the
+pull-down resistor. "ZR" can be abbreviates to "R".
+
+Example:
+# gpio b0=1 b1=r b2=z
+
+Assignments can be mixed with reads, e.g.,
+# gpio b0=1 b0
+
+
Added: trunk/src/target/gpio/gpio.c
===================================================================
--- trunk/src/target/gpio/gpio.c 2008-02-21 11:41:29 UTC (rev 4101)
+++ trunk/src/target/gpio/gpio.c 2008-02-22 12:01:09 UTC (rev 4102)
@@ -0,0 +1,319 @@
+/*
+ * gpio - Read and set GPIO pins (of the Samsung S3C2442 MCU)
+ *
+ * Copyright (C) 2008 by OpenMoko, Inc.
+ * Written by Werner Almesberger <[EMAIL PROTECTED]>
+ * All Rights Reserved
+ *
+ * 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 <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+
+#define BASE 0x56000000
+
+
+static volatile void *mem;
+
+
+#define CON_IN 0
+#define CON_OUT 1
+#define CON_F1 2
+#define CON_F2 3
+
+
+/* 2442 port assignment */
+
+static struct port {
+ const char *name;
+ int offset;
+ int last;
+ enum { pt_a, pt_b } type;
+} ports[] = {
+ { "A", 0x00, 22, pt_a },
+ { "B", 0x10, 10, pt_b },
+ { "C", 0x20, 15, pt_b },
+ { "D", 0x30, 15, pt_b },
+ { "E", 0x40, 15, pt_b },
+ { "F", 0x50, 7, pt_b },
+ { "G", 0x60, 15, pt_b },
+ { "H", 0x70, 10, pt_b },
+ { "J", 0xd0, 12, pt_b },
+ { NULL, }
+};
+
+
+static void print_n(const char *name, int last)
+{
+ int i;
+
+ printf("%s ", name);
+ for (i = 0; i <= last; i++)
+ printf("%2d ", i);
+ putchar('\n');
+}
+
+
+/* ----- Read a pin -------------------------------------------------------- */
+
+
+static const char *pin_a(int con, int dat)
+{
+ if (con)
+ return dat ? "F1" : "F0";
+ else
+ return dat ? " 1" : " 0";
+}
+
+
+static const char *pin_b(int con, int dat, int pud)
+{
+ static char res[4];
+
+ res[0] = " >FX"[con];
+ res[1] = dat ? '1' : '0';
+ res[2] = pud ? ' ' : 'R';
+ return res;
+}
+
+
+static const char *pin(const struct port *p, int num)
+{
+ uint32_t con, dat, pud;
+
+ con = *(uint32_t *) (mem+p->offset);
+ dat = *(uint32_t *) (mem+p->offset+4);
+ if (p->type == pt_a)
+ return pin_a((con >> num) & 1, (dat >> num) & 1);
+ else {
+ pud = *(uint32_t *) (mem+p->offset+8);
+ return pin_b((con >> (num*2)) & 3, (dat >> num) & 1,
+ (pud >> num) & 1);
+ }
+}
+
+
+/* ----- Set a pin --------------------------------------------------------- */
+
+
+static void set_a(const struct port *p, int num, int c, int d)
+{
+ uint32_t con, dat;
+
+ con = *(uint32_t *) (mem+p->offset);
+ con = (con & ~(1 << num)) | ((c == CON_F1) << num);
+ *(uint32_t *) (mem+p->offset) = con;
+
+ if (d != -1) {
+ dat = *(uint32_t *) (mem+p->offset+4);
+ dat = (dat & ~(1 << num)) | (d << num);
+ *(uint32_t *) (mem+p->offset+4) = dat;
+ }
+}
+
+
+static void set_b(const struct port *p, int num, int c, int d, int r)
+{
+ uint32_t con, dat, pud;
+
+ con = *(uint32_t *) (mem+p->offset);
+ con = (con & ~(3 << (num*2))) | (c << (num*2));
+ *(uint32_t *) (mem+p->offset) = con;
+
+ if (d != -1) {
+ dat = *(uint32_t *) (mem+p->offset+4);
+ dat = (dat & ~(1 << num)) | (d << num);
+ *(uint32_t *) (mem+p->offset+4) = dat;
+ }
+
+ pud = *(uint32_t *) (mem+p->offset+8);
+ pud = (pud & ~(1 << num)) | (!r << num);
+ *(uint32_t *) (mem+p->offset+8) = pud;
+}
+
+
+static void set_pin(const struct port *p, int num, int c, int d, int r)
+{
+ if (num > p->last) {
+ fprintf(stderr, "invalid pin %s%d\n", p->name, num);
+ exit(1);
+ }
+ if (p->type == pt_a) {
+ if (r) {
+ fprintf(stderr, "pin %s%d has no pull-down\n",
+ p->name, num);
+ exit(1);
+ }
+ if (c == CON_IN) {
+ fprintf(stderr, "pin %s%d cannot be an input\n",
+ p->name, num);
+ exit(1);
+ }
+ if (c == CON_F2) {
+ fprintf(stderr, "pin %s%d has no second function\n",
+ p->name, num);
+ exit(1);
+ }
+ set_a(p, num, c, d);
+ }
+ else
+ set_b(p, num, c, d, r);
+}
+
+
+/* ----- Dump all ports ---------------------------------------------------- */
+
+
+static void dump_all(void)
+{
+ const struct port *p;
+ uint32_t con, dat, pud;
+ int i;
+
+ for (p = ports; p->name; p++) {
+ con = *(uint32_t *) (mem+p->offset);
+ dat = *(uint32_t *) (mem+p->offset+4);
+ if (p->type == pt_a) {
+ print_n(p->name, p->last);
+ printf("%*s ", strlen(p->name), "");
+ for (i = 0; i <= p->last; i++)
+ printf("%s ",
+ pin_a((con >> i) & 1, (dat >> i) & 1));
+ putchar('\n');
+ }
+ else {
+ pud = *(uint32_t *) (mem+p->offset+8);
+ print_n(p->name, p->last);
+ printf("%*s ", strlen(p->name), "");
+ for (i = 0; i <= p->last; i++)
+ printf("%s",
+ pin_b((con >> (i*2)) & 3, (dat >> i) & 1,
+ (pud >> i) & 1));
+ putchar('\n');
+ }
+ }
+}
+
+
+/* ----- Command-line parsing ---------------------------------------------- */
+
+
+static void __attribute__((noreturn)) usage(const char *name)
+{
+ fprintf(stderr,
+"usage: %s [pin[=value] ...]\n\n"
+" pin = <letter><number>, e.g., A5, b10\n"
+" value = <control><pull-down>, with\n"
+" <control> = 0 (output 0), 1 (output 1), Z (input), F (primary\n"
+" function), X (secondary function)\n"
+" <pull-down> = R (pull-down active) or nothing\n"
+" As a short-cut, ZR can be abbreviated as R.\n\n"
+" Examples: A5=ZR, b10=0\n",
+ name);
+ exit(1);
+}
+
+
+static void port_op(const char *name, const char *op)
+{
+ const char *eq, *s;
+ const struct port *p;
+ int num, c, d = -1, r = 0;
+ char *end;
+
+ eq = strchr(op, '=');
+ if (!eq)
+ eq = strchr(op, 0);
+ num = strcspn(op, "0123456789");
+ if (!num || op+num >= eq)
+ usage(name);
+ for (p = ports; p->name; p++)
+ if (strlen(p->name) == num && !strncasecmp(p->name, op, num))
+ break;
+ if (!p->name) {
+ fprintf(stderr, "invalid port \"%.*s\"\n", num, op);
+ exit(1);
+ }
+ num = strtoul(op+num, &end, 10);
+ if (end != eq)
+ usage(name);
+ if (!*eq) {
+ s = pin(p, num);
+ if (*s == ' ')
+ s++;
+ printf("%s\n", s);
+ return;
+ }
+ switch (eq[1]) {
+ case '0':
+ d = 0;
+ c = CON_OUT;
+ break;
+ case '1':
+ d = 1;
+ c = CON_OUT;
+ break;
+ case 'Z':
+ case 'z':
+ c = CON_IN;
+ break;
+ case 'R':
+ case 'r':
+ if (eq[2])
+ usage(name);
+ c = CON_IN;
+ r = 1;
+ break;
+ case 'F':
+ case 'f':
+ c = CON_F1;
+ break;
+ case 'X':
+ case 'x':
+ c = CON_F2;
+ break;
+ default:
+ usage(name);
+ }
+ if (eq[2]) {
+ if (eq[2] != 'R' && eq[2] != 'r')
+ usage(name);
+ if (eq[3])
+ usage(name);
+ r = 1;
+ }
+ set_pin(p, num, c, d, r);
+}
+
+
+int main(int argc, char **argv)
+{
+ int fd, i;
+
+ fd = open("/dev/mem", O_RDWR);
+ if (fd < 0) {
+ perror("/dev/mem");
+ exit(1);
+ }
+ mem = mmap(NULL, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, BASE);
+ if (mem == MAP_FAILED) {
+ perror("mmap");
+ exit(1);
+ }
+ if (argc == 1)
+ dump_all();
+ else
+ for (i = 1; i != argc; i++)
+ port_op(*argv, argv[i]);
+ return 0;
+}
--- End Message ---
