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This creates an example Counter program under tools/counter/* to exemplify the Counter character device interface. Cc: Pavel Machek <[email protected]> Signed-off-by: William Breathitt Gray <[email protected]> Link: https://lore.kernel.org/r/7c0f975ba098952122302d258ec9ffdef04befaf.1632884256.git.vilhelm.gray@gmail.com Signed-off-by: Jonathan Cameron <[email protected]>
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@@ -4805,6 +4805,7 @@ F: Documentation/driver-api/generic-counter.rst | |
| F: drivers/counter/ | ||
| F: include/linux/counter.h | ||
| F: include/uapi/linux/counter.h | ||
| F: tools/counter/ | ||
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| CP2615 I2C DRIVER | ||
| M: Bence Csókás <[email protected]> | ||
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| counter_example-y += counter_example.o |
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| # SPDX-License-Identifier: GPL-2.0 | ||
| include ../scripts/Makefile.include | ||
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| bindir ?= /usr/bin | ||
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| ifeq ($(srctree),) | ||
| srctree := $(patsubst %/,%,$(dir $(CURDIR))) | ||
| srctree := $(patsubst %/,%,$(dir $(srctree))) | ||
| endif | ||
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| # Do not use make's built-in rules | ||
| # (this improves performance and avoids hard-to-debug behaviour); | ||
| MAKEFLAGS += -r | ||
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| override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include | ||
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| ALL_TARGETS := counter_example | ||
| ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS)) | ||
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| all: $(ALL_PROGRAMS) | ||
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| export srctree OUTPUT CC LD CFLAGS | ||
| include $(srctree)/tools/build/Makefile.include | ||
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| # | ||
| # We need the following to be outside of kernel tree | ||
| # | ||
| $(OUTPUT)include/linux/counter.h: ../../include/uapi/linux/counter.h | ||
| mkdir -p $(OUTPUT)include/linux 2>&1 || true | ||
| ln -sf $(CURDIR)/../../include/uapi/linux/counter.h $@ | ||
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| prepare: $(OUTPUT)include/linux/counter.h | ||
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| COUNTER_EXAMPLE := $(OUTPUT)counter_example.o | ||
| $(COUNTER_EXAMPLE): prepare FORCE | ||
| $(Q)$(MAKE) $(build)=counter_example | ||
| $(OUTPUT)counter_example: $(COUNTER_EXAMPLE) | ||
| $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@ | ||
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| clean: | ||
| rm -f $(ALL_PROGRAMS) | ||
| rm -rf $(OUTPUT)include/linux/counter.h | ||
| find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete | ||
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| install: $(ALL_PROGRAMS) | ||
| install -d -m 755 $(DESTDIR)$(bindir); \ | ||
| for program in $(ALL_PROGRAMS); do \ | ||
| install $$program $(DESTDIR)$(bindir); \ | ||
| done | ||
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| FORCE: | ||
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| .PHONY: all install clean FORCE prepare |
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| // SPDX-License-Identifier: GPL-2.0-only | ||
| /* Counter - example userspace application | ||
| * | ||
| * The userspace application opens /dev/counter0, configures the | ||
| * COUNTER_EVENT_INDEX event channel 0 to gather Count 0 count and Count | ||
| * 1 count, and prints out the data as it becomes available on the | ||
| * character device node. | ||
| * | ||
| * Copyright (C) 2021 William Breathitt Gray | ||
| */ | ||
| #include <errno.h> | ||
| #include <fcntl.h> | ||
| #include <linux/counter.h> | ||
| #include <stdio.h> | ||
| #include <string.h> | ||
| #include <sys/ioctl.h> | ||
| #include <unistd.h> | ||
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| static struct counter_watch watches[2] = { | ||
| { | ||
| /* Component data: Count 0 count */ | ||
| .component.type = COUNTER_COMPONENT_COUNT, | ||
| .component.scope = COUNTER_SCOPE_COUNT, | ||
| .component.parent = 0, | ||
| /* Event type: Index */ | ||
| .event = COUNTER_EVENT_INDEX, | ||
| /* Device event channel 0 */ | ||
| .channel = 0, | ||
| }, | ||
| { | ||
| /* Component data: Count 1 count */ | ||
| .component.type = COUNTER_COMPONENT_COUNT, | ||
| .component.scope = COUNTER_SCOPE_COUNT, | ||
| .component.parent = 1, | ||
| /* Event type: Index */ | ||
| .event = COUNTER_EVENT_INDEX, | ||
| /* Device event channel 0 */ | ||
| .channel = 0, | ||
| }, | ||
| }; | ||
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| int main(void) | ||
| { | ||
| int fd; | ||
| int ret; | ||
| int i; | ||
| struct counter_event event_data[2]; | ||
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| fd = open("/dev/counter0", O_RDWR); | ||
| if (fd == -1) { | ||
| perror("Unable to open /dev/counter0"); | ||
| return 1; | ||
| } | ||
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| for (i = 0; i < 2; i++) { | ||
| ret = ioctl(fd, COUNTER_ADD_WATCH_IOCTL, watches + i); | ||
| if (ret == -1) { | ||
| fprintf(stderr, "Error adding watches[%d]: %s\n", i, | ||
| strerror(errno)); | ||
| return 1; | ||
| } | ||
| } | ||
| ret = ioctl(fd, COUNTER_ENABLE_EVENTS_IOCTL); | ||
| if (ret == -1) { | ||
| perror("Error enabling events"); | ||
| return 1; | ||
| } | ||
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| for (;;) { | ||
| ret = read(fd, event_data, sizeof(event_data)); | ||
| if (ret == -1) { | ||
| perror("Failed to read event data"); | ||
| return 1; | ||
| } | ||
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| if (ret != sizeof(event_data)) { | ||
| fprintf(stderr, "Failed to read event data\n"); | ||
| return -EIO; | ||
| } | ||
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| printf("Timestamp 0: %llu\tCount 0: %llu\n" | ||
| "Error Message 0: %s\n" | ||
| "Timestamp 1: %llu\tCount 1: %llu\n" | ||
| "Error Message 1: %s\n", | ||
| event_data[0].timestamp, event_data[0].value, | ||
| strerror(event_data[0].status), | ||
| event_data[1].timestamp, event_data[1].value, | ||
| strerror(event_data[1].status)); | ||
| } | ||
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| return 0; | ||
| } |