dm: use power button acpi device to find its input event

check the power button acpi driver firstly, then find input event
corresponding to the power button.

Tracked-On: #2695
Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

devicemodel/arch/x86/pm.c

@@ -37,6 +37,9 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <linux/input.h>
+#include <dirent.h>
+#include <string.h>
+#include <stdlib.h>
 
 #include "vmmapi.h"
 #include "acpi.h"
@@ -46,8 +49,9 @@
 #include "lpc.h"
 #include "monitor.h"
 
-#define POWER_BUTTON_EVENT	116
 #define POWER_BUTTON_NAME	"power_button"
+#define POWER_BUTTON_ACPI_DRV	"/sys/bus/acpi/drivers/button/LNXPWRBN:00/"
+#define POWER_BUTTON_INPUT_DIR POWER_BUTTON_ACPI_DRV"input"
 static pthread_mutex_t pm_lock = PTHREAD_MUTEX_INITIALIZER;
 static struct mevent *power_button;
 static sig_t old_power_handler;
@@ -242,6 +246,7 @@ INOUT_PORT(pm1_enable, PM1A_EVT_ADDR + 2, IOPORT_F_INOUT, pm1_enable_handler);
 static void
 power_button_press_emulation(struct vmctx *ctx)
 {
+	printf("%s", "press power button\n");
 	pthread_mutex_lock(&pm_lock);
 	if (!(pm1_status & PM1_PWRBTN_STS)) {
 		pm1_status |= PM1_PWRBTN_STS;
@@ -267,7 +272,11 @@ input_event0_handler(int fd, enum ev_type type, void *arg)
 	if (rc < 0 || rc != sizeof(ev))
 		return;
 
-	if (ev.code == POWER_BUTTON_EVENT && ev.value == 1)
+	/*
+	 * The input key defines in input-event-codes.h
+	 * KEY_POWER 116 SC System Power Down
+	 */
+	if (ev.code == KEY_POWER && ev.value == 1)
 		power_button_press_emulation(arg);
 }
 
@@ -336,6 +345,109 @@ static struct monitor_vm_ops vm_ops = {
 	.suspend = vm_suspend_handler,
 };
 
+static int
+input_dir_filter(const struct dirent *dir)
+{
+	return !strncmp(dir->d_name, "input", 5);
+}
+
+static int
+event_dir_filter(const struct dirent *dir)
+{
+	return !strncmp(dir->d_name, "event", 5);
+}
+
+static int
+open_power_button_input_device()
+{
+	struct dirent **input_dirs = NULL;
+	struct dirent **event_dirs = NULL;
+	int ninput = 0;
+	int nevent = 0;
+	char path[256] = {0};
+	char name[256] = {0};
+	int rc, fd;
+
+	if (access(POWER_BUTTON_ACPI_DRV, F_OK) != 0) {
+		fprintf(stderr, "failed to detect power button driver\n");
+		return -1;
+	}
+
+	/*
+	 * Scan path to get inputN
+	 * path is /sys/bus/acpi/drivers/button/LNXPWRBN:00/input
+	 */
+	ninput = scandir(POWER_BUTTON_INPUT_DIR, &input_dirs, input_dir_filter,
+			alphasort);
+	if (ninput < 0) {
+		fprintf(stderr, "failed to scan power button %s\n",
+				POWER_BUTTON_INPUT_DIR);
+		goto err;
+	} else if (ninput == 1) {
+		rc = snprintf(path, sizeof(path), "%s/%s",
+				POWER_BUTTON_INPUT_DIR, input_dirs[0]->d_name);
+		if (rc < 0 || rc >= sizeof(path)) {
+			fprintf(stderr, "failed to set power button path %d\n",
+					rc);
+			goto err_input;
+		}
+
+		/*
+		 * Scan path to get eventN
+		 * path is /sys/bus/acpi/drivers/button/LNXPWRBN:00/input/inputN
+		 */
+		nevent = scandir(path, &event_dirs, event_dir_filter,
+				alphasort);
+		if (nevent < 0) {
+			fprintf(stderr, "failed to get power button event %s\n",
+					path);
+			goto err_input;
+		} else if (nevent == 1) {
+
+			/* Get the power button input event name */
+			rc = snprintf(name, sizeof(name), "/dev/input/%s",
+					event_dirs[0]->d_name);
+			if (rc < 0 || rc >= sizeof(name)) {
+				fprintf(stderr, "power button error %d\n", rc);
+				goto err_input;
+			}
+		} else {
+			fprintf(stderr, "power button event number error %d\n",
+					nevent);
+			goto err_event;
+		}
+	} else {
+		fprintf(stderr, "power button input number error %d\n", nevent);
+		goto err_input;
+	}
+
+	/* Open the input device */
+	fd = open(name, O_RDONLY);
+	if (fd > 0)
+		printf("Watching power button on %s\n", name);
+
+	while (nevent--)
+		free(event_dirs[nevent]);
+	free(event_dirs);
+	while (ninput--)
+		free(input_dirs[ninput]);
+	free(input_dirs);
+	return fd;
+
+err_event:
+	while (nevent--)
+		free(event_dirs[nevent]);
+	free(event_dirs);
+
+err_input:
+	while (ninput--)
+		free(input_dirs[ninput]);
+	free(input_dirs);
+
+err:
+	return -1;
+}
+
 /*
  * ACPI SMI Command Register
  *
@@ -371,11 +483,8 @@ smi_cmd_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
 			old_power_handler = signal(SIGTERM, SIG_IGN);
 		}
 		if (input_evt0 == NULL) {
-			/*
-			 * FIXME: check /sys/bus/acpi/devices/LNXPWRBN\:00/input to
-			 * get input event node instead hardcode in here.
-			 */
-			pwrbtn_fd = open("/dev/input/event0", O_RDONLY);
+
+			pwrbtn_fd = open_power_button_input_device();
 			if (pwrbtn_fd < 0)
 				fprintf(stderr, "open input event0 error=%d\n",
 						errno);