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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /samples/timers/hpet_example.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'samples/timers/hpet_example.c')
-rw-r--r--samples/timers/hpet_example.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/samples/timers/hpet_example.c b/samples/timers/hpet_example.c
new file mode 100644
index 000000000..f1cb622f6
--- /dev/null
+++ b/samples/timers/hpet_example.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <memory.h>
+#include <malloc.h>
+#include <time.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <linux/hpet.h>
+
+
+extern void hpet_open_close(int, const char **);
+extern void hpet_info(int, const char **);
+extern void hpet_poll(int, const char **);
+extern void hpet_fasync(int, const char **);
+extern void hpet_read(int, const char **);
+
+#include <sys/poll.h>
+#include <sys/ioctl.h>
+
+struct hpet_command {
+ char *command;
+ void (*func)(int argc, const char ** argv);
+} hpet_command[] = {
+ {
+ "open-close",
+ hpet_open_close
+ },
+ {
+ "info",
+ hpet_info
+ },
+ {
+ "poll",
+ hpet_poll
+ },
+ {
+ "fasync",
+ hpet_fasync
+ },
+};
+
+int
+main(int argc, const char ** argv)
+{
+ unsigned int i;
+
+ argc--;
+ argv++;
+
+ if (!argc) {
+ fprintf(stderr, "-hpet: requires command\n");
+ return -1;
+ }
+
+
+ for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++)
+ if (!strcmp(argv[0], hpet_command[i].command)) {
+ argc--;
+ argv++;
+ fprintf(stderr, "-hpet: executing %s\n",
+ hpet_command[i].command);
+ hpet_command[i].func(argc, argv);
+ return 0;
+ }
+
+ fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]);
+
+ return -1;
+}
+
+void
+hpet_open_close(int argc, const char **argv)
+{
+ int fd;
+
+ if (argc != 1) {
+ fprintf(stderr, "hpet_open_close: device-name\n");
+ return;
+ }
+
+ fd = open(argv[0], O_RDONLY);
+ if (fd < 0)
+ fprintf(stderr, "hpet_open_close: open failed\n");
+ else
+ close(fd);
+
+ return;
+}
+
+void
+hpet_info(int argc, const char **argv)
+{
+ struct hpet_info info;
+ int fd;
+
+ if (argc != 1) {
+ fprintf(stderr, "hpet_info: device-name\n");
+ return;
+ }
+
+ fd = open(argv[0], O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "hpet_info: open of %s failed\n", argv[0]);
+ return;
+ }
+
+ if (ioctl(fd, HPET_INFO, &info) < 0) {
+ fprintf(stderr, "hpet_info: failed to get info\n");
+ goto out;
+ }
+
+ fprintf(stderr, "hpet_info: hi_irqfreq 0x%lx hi_flags 0x%lx ",
+ info.hi_ireqfreq, info.hi_flags);
+ fprintf(stderr, "hi_hpet %d hi_timer %d\n",
+ info.hi_hpet, info.hi_timer);
+
+out:
+ close(fd);
+ return;
+}
+
+void
+hpet_poll(int argc, const char **argv)
+{
+ unsigned long freq;
+ int iterations, i, fd;
+ struct pollfd pfd;
+ struct hpet_info info;
+ struct timeval stv, etv;
+ struct timezone tz;
+ long usec;
+
+ if (argc != 3) {
+ fprintf(stderr, "hpet_poll: device-name freq iterations\n");
+ return;
+ }
+
+ freq = atoi(argv[1]);
+ iterations = atoi(argv[2]);
+
+ fd = open(argv[0], O_RDONLY);
+
+ if (fd < 0) {
+ fprintf(stderr, "hpet_poll: open of %s failed\n", argv[0]);
+ return;
+ }
+
+ if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
+ fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n");
+ goto out;
+ }
+
+ if (ioctl(fd, HPET_INFO, &info) < 0) {
+ fprintf(stderr, "hpet_poll: failed to get info\n");
+ goto out;
+ }
+
+ fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags);
+
+ if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
+ fprintf(stderr, "hpet_poll: HPET_EPI failed\n");
+ goto out;
+ }
+
+ if (ioctl(fd, HPET_IE_ON, 0) < 0) {
+ fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n");
+ goto out;
+ }
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+
+ for (i = 0; i < iterations; i++) {
+ pfd.revents = 0;
+ gettimeofday(&stv, &tz);
+ if (poll(&pfd, 1, -1) < 0)
+ fprintf(stderr, "hpet_poll: poll failed\n");
+ else {
+ long data;
+
+ gettimeofday(&etv, &tz);
+ usec = stv.tv_sec * 1000000 + stv.tv_usec;
+ usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec;
+
+ fprintf(stderr,
+ "hpet_poll: expired time = 0x%lx\n", usec);
+
+ fprintf(stderr, "hpet_poll: revents = 0x%x\n",
+ pfd.revents);
+
+ if (read(fd, &data, sizeof(data)) != sizeof(data)) {
+ fprintf(stderr, "hpet_poll: read failed\n");
+ }
+ else
+ fprintf(stderr, "hpet_poll: data 0x%lx\n",
+ data);
+ }
+ }
+
+out:
+ close(fd);
+ return;
+}
+
+static int hpet_sigio_count;
+
+static void
+hpet_sigio(int val)
+{
+ fprintf(stderr, "hpet_sigio: called\n");
+ hpet_sigio_count++;
+}
+
+void
+hpet_fasync(int argc, const char **argv)
+{
+ unsigned long freq;
+ int iterations, i, fd, value;
+ sig_t oldsig;
+ struct hpet_info info;
+
+ hpet_sigio_count = 0;
+ fd = -1;
+
+ if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) {
+ fprintf(stderr, "hpet_fasync: failed to set signal handler\n");
+ return;
+ }
+
+ if (argc != 3) {
+ fprintf(stderr, "hpet_fasync: device-name freq iterations\n");
+ goto out;
+ }
+
+ fd = open(argv[0], O_RDONLY);
+
+ if (fd < 0) {
+ fprintf(stderr, "hpet_fasync: failed to open %s\n", argv[0]);
+ return;
+ }
+
+
+ if ((fcntl(fd, F_SETOWN, getpid()) == 1) ||
+ ((value = fcntl(fd, F_GETFL)) == 1) ||
+ (fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) {
+ fprintf(stderr, "hpet_fasync: fcntl failed\n");
+ goto out;
+ }
+
+ freq = atoi(argv[1]);
+ iterations = atoi(argv[2]);
+
+ if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
+ fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n");
+ goto out;
+ }
+
+ if (ioctl(fd, HPET_INFO, &info) < 0) {
+ fprintf(stderr, "hpet_fasync: failed to get info\n");
+ goto out;
+ }
+
+ fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags);
+
+ if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
+ fprintf(stderr, "hpet_fasync: HPET_EPI failed\n");
+ goto out;
+ }
+
+ if (ioctl(fd, HPET_IE_ON, 0) < 0) {
+ fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n");
+ goto out;
+ }
+
+ for (i = 0; i < iterations; i++) {
+ (void) pause();
+ fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count);
+ }
+
+out:
+ signal(SIGIO, oldsig);
+
+ if (fd >= 0)
+ close(fd);
+
+ return;
+}