Add very early version of software beep utility

2 files changed, 132 insertions, 0 deletions

diff --git a/softbeep/Makefile b/softbeep/Makefile
new file mode 100644
index 0000000..77e763b
--- /dev/null
+++ b/softbeep/Makefile
@@ -0,0 +1,3 @@
+BINS=beep
+include ../gdbus.mk
+include ../rules.mk
diff --git a/softbeep/beep_obj.c b/softbeep/beep_obj.c
new file mode 100644
index 0000000..ec05ad3
--- /dev/null
+++ b/softbeep/beep_obj.c
@@ -0,0 +1,129 @@
+/* Copyright 2018 Raptor Engineering, LLC
+ *
+ * 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/>.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <time.h>
+#include <assert.h>
+#include <inttypes.h>
+
+#define GPIO_BASE	0x1e780000
+#define GPIO_DATA	0x0
+#define GPIO_DIR	0x4
+
+#define GPIO_BANK_MNOP	0x78
+#define GPIO_N7_MASK	0x00008000
+
+static void *gpio_reg = NULL;
+static int mem_fd = 0;
+
+inline void timespec_diff(struct timespec *start, struct timespec *stop, struct timespec *result) {
+	if ((stop->tv_nsec - start->tv_nsec) < 0) {
+		result->tv_sec = stop->tv_sec - start->tv_sec - 1;
+		result->tv_nsec = stop->tv_nsec - start->tv_nsec + 1000000000;
+	}
+	else {
+		result->tv_sec = stop->tv_sec - start->tv_sec;
+		result->tv_nsec = stop->tv_nsec - start->tv_nsec;
+	}
+
+	return;
+}
+
+void delay_for_interval(uint32_t interval) {
+	uint32_t abort_count = 0;
+	uint64_t delay_ns = interval * 1000;
+
+	struct timespec start_time = {.tv_sec=0,.tv_nsec=0};
+	struct timespec current_time = {.tv_sec=0,.tv_nsec=0};
+	struct timespec difference_time = {.tv_sec=0,.tv_nsec=0};
+
+	abort_count = 0;
+	while (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) < 0) {
+		abort_count++;
+		if (abort_count > 10) {
+			return;
+		}
+	}
+	while (1) {
+		current_time.tv_sec = 0;
+		current_time.tv_nsec = 0;
+		if (clock_gettime(CLOCK_MONOTONIC_RAW, &current_time) < 0) {
+			continue;
+		}
+		timespec_diff(&start_time, &current_time, &difference_time);
+		if (difference_time.tv_nsec > delay_ns) {
+			break;
+		}
+	}
+
+	if (difference_time.tv_nsec > (delay_ns * 2)) {
+		printf("OVERRAN timer (wanted %lld, got %lld, start: %lld.%lld end: %lld.%lld)\n", delay_ns, difference_time.tv_nsec, start_time.tv_sec, start_time.tv_nsec, current_time.tv_sec, current_time.tv_nsec);
+	}
+}
+
+int main(void) {
+	uint32_t run_cycles;
+	uint32_t frequency = 1000;
+	uint32_t period = 1000000 / frequency;
+	uint32_t halfperiod = period / 2;
+	uint32_t duration_ms = 100;
+	uint32_t num_cycles = (duration_ms * frequency) / 1000;
+
+	// Open physical memory device
+	if (!mem_fd) {
+		mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+		if (mem_fd < 0) {
+			perror("Unable to open /dev/mem");
+			exit(1);
+		}
+	}
+
+	// Map GPIO registers into virtual memory
+	gpio_reg = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, GPIO_BASE);
+	if (gpio_reg == MAP_FAILED) {
+		perror("Unable to map GPIO register memory");
+		exit(-1);
+	}
+
+	// Elevate priority
+	if (setpriority(PRIO_PROCESS, 0, -20) < 0) {
+		perror("Unable to set priority");
+		exit(-1);
+	}
+
+	// Set GPIO N7 to OUTPUT
+	uint32_t *offset = gpio_reg + GPIO_BANK_MNOP + GPIO_DIR;
+	*offset |= GPIO_N7_MASK;
+
+	// Set up GPIO N7 access
+	offset = gpio_reg + GPIO_BANK_MNOP + GPIO_DATA;
+	for (run_cycles = 0; run_cycles < 100; run_cycles++) {
+		delay_for_interval(halfperiod);
+		*offset |= GPIO_N7_MASK;
+		delay_for_interval(halfperiod);
+		*offset &= ~GPIO_N7_MASK;
+	}
+
+	return 0;
+}