From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Date: Wed, 11 Mar 2026 18:24:56 +0000 (-0400)
Subject: Add Battery low voltage detection get/set
X-Git-Url: http://gitweb.hugovil.com/sitemap.xml?a=commitdiff_plain;h=2f5ab17c0836cf4836be35cd87b17779676ebe88;p=hvrtc.git

Add Battery low voltage detection get/set

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---

diff --git a/src/main.c b/src/main.c
index 19a39d5..7447281 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,6 +26,53 @@
 
 extern struct options_t options;
 
+static int rtc_param_get_batlow(int fd)
+{
+	const char *mode;
+	struct rtc_param par;
+	int ret;
+
+	par.param = RTC_PARAM_BATTERY_LOW_DETECT;
+	ret = ioctl(fd, RTC_PARAM_GET, &par);
+	if (ret < 0) {
+		perror("get RTC_PARAM_BATTERY_LOW_DETECT");
+		return ret;
+	}
+
+	switch (par.uvalue) {
+	case RTC_BATTERY_LOW_DETECT_DISABLED:
+		mode = "disabled";
+		break;
+	case RTC_BATTERY_LOW_DETECT_ENABLED:
+		mode = "enabled";
+		break;
+	default:
+		mode = "unknown";
+		break;
+	};
+
+	printf("Battery low detection: %s\n", mode);
+
+	return 0;
+}
+
+static int rtc_param_set_batlow(int fd, int value)
+{
+	struct rtc_param par;
+	int ret;
+
+	par.param = RTC_PARAM_BATTERY_LOW_DETECT;
+	par.uvalue = value;
+
+	ret = ioctl(fd, RTC_PARAM_SET, &par);
+	if (ret < 0) {
+		perror("get RTC_PARAM_BATTERY_LOW_DETECT");
+		return ret;
+	}
+
+	return 0;
+}
+
 static int rtc_param_get_bsm(int fd)
 {
 	const char *mode;
@@ -444,6 +491,18 @@ main(int argc, char **argv)
 		}
 	}
 
+	if (options.batlow) {
+		if (options.batlow_arg >= 0) {
+			rc = rtc_param_set_batlow(fd, options.batlow_arg);
+			if (rc < 0)
+				exit(rc);
+		} else {
+			rc = rtc_param_get_batlow(fd);
+			if (rc < 0)
+				exit(rc);
+		}
+	}
+
 	if (options.vl_backup) {
 		rc = rtc_param_get_vl_backup(fd);
 		if (rc < 0)
diff --git a/src/options.c b/src/options.c
index 68eb3d1..cdd23c0 100644
--- a/src/options.c
+++ b/src/options.c
@@ -55,12 +55,18 @@ static const char args_doc[] = "";
 	"    level    RTC_BSM_LEVEL\n"					\
 	"    standby  RTC_BSM_STANDBY"
 
+#define ARGP_BATLOW_STR				\
+	"    enabled\n"				\
+	"    disabled"
+
 /* The options we understand. */
 static struct argp_option argp_options[] = {
 	{"bsm",   'b', "value",   OPTION_ARG_OPTIONAL, "Get/Set Backup Switch Mode (BSM):", 0},
 	{0,       0,   0,         0,                   ARGP_BSM_STR, 0},
 	{"clear", 'c', 0,         0, "Clear \"voltage low\" event", 0},
 	{"dev",   'd', "path",    0, "RTC device path (optional)", 0},
+	{"lowbat",'l', "value",   OPTION_ARG_OPTIONAL, "Get/Set Battery low voltage detection:", 0},
+	{0,       0,   0,         0,                   ARGP_BATLOW_STR, 0},
 	{"test",  'x', 0,         0, "Test RTC", 0},
 	{"time",  't', 0,         0, "Get RTC time", 0},
 	{"voltage-level", 'v', 0, 0, "Get battery backup voltage level", 0},
@@ -114,6 +120,19 @@ decode_bsm(char *arg, struct argp_state *state)
 	}
 }
 
+static void
+decode_batlow(char *arg, struct argp_state *state)
+{
+	if (STREQ(arg, "enabled")) {
+		options.batlow_arg = RTC_BATTERY_LOW_DETECT_ENABLED;
+	} else if (STREQ(arg, "disabled")) {
+		options.batlow_arg = RTC_BATTERY_LOW_DETECT_DISABLED;
+	} else {
+		log_fail("Unknown battery low detection value: %s\n", arg);
+		argp_usage(state);
+	}
+}
+
 /* Parse a single option. */
 static error_t
 parse_opt(int key, char *arg, struct argp_state *state)
@@ -138,6 +157,11 @@ parse_opt(int key, char *arg, struct argp_state *state)
 		/* We do not support any arguments after the options. */
 		argp_usage(state);
 		break;
+	case 'l':
+		options.batlow = true;
+		if (arg)
+			decode_batlow(arg, state);
+		break;
 	case 't':
 		options.time = true;
 		break;
@@ -167,6 +191,7 @@ int parse_command_line_options(int argc, char *argv[])
 	bzero(&options, sizeof(struct options_t));
 	options.rtc_path = "/dev/rtc0";
 	options.bsm_arg = -1;
+	options.batlow_arg = -1;
 
 	/* Parse our arguments. */
 	rc = argp_parse(&argp, argc, argv, 0, 0, NULL);
diff --git a/src/options.h b/src/options.h
index 97685e4..9b6d26e 100644
--- a/src/options.h
+++ b/src/options.h
@@ -15,6 +15,16 @@
 
 #define PACKAGE_DESCRIPTION "RTC configuration/query tool"
 
+/*
+ * Temporary: from kernel headers.
+ * Remove once kernel headers incorporate these:
+ */
+#ifndef RTC_PARAM_BATTERY_LOW_DETECT
+#define RTC_PARAM_BATTERY_LOW_DETECT 3
+#define RTC_BATTERY_LOW_DETECT_DISABLED	0
+#define RTC_BATTERY_LOW_DETECT_ENABLED	1
+#endif
+
 struct options_t {
 	char *rtc_path;
 	int bsm;
@@ -23,6 +33,8 @@ struct options_t {
 	int clear;
 	int test;
 	int time;
+	int batlow;
+	int batlow_arg;
 };
 
 int parse_command_line_options(int argc, char *argv[]);