[PATCH] cmd: adc: Add support for storing ADC result in env variable

[Marek Vasut]

Add the ability to start ADC conversion result in an environment
variable. This is useful for further arbitrary processing by the
U-Boot scripts.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Fabrice Gasnier <fabrice.gasnier at foss.st.com>
Cc: Simon Glass <sjg at chromium.org>
---
 cmd/adc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/cmd/adc.c b/cmd/adc.c
index 75739bc8eed..4f548b811ec 100644
--- a/cmd/adc.c
+++ b/cmd/adc.c
@@ -71,6 +71,7 @@ static int do_adc_info(struct cmd_tbl *cmdtp, int flag, int argc,
 static int do_adc_single(struct cmd_tbl *cmdtp, int flag, int argc,
 			 char *const argv[])
 {
+	char *varname = NULL;
 	struct udevice *dev;
 	unsigned int data;
 	int ret, uV;
@@ -78,6 +79,9 @@ static int do_adc_single(struct cmd_tbl *cmdtp, int flag, int argc,
 	if (argc < 3)
 		return CMD_RET_USAGE;
 
+	if (argc >= 3)
+		varname = argv[2];
+
 	ret = adc_channel_single_shot(argv[1], simple_strtol(argv[2], NULL, 0),
 				      &data);
 	if (ret) {
@@ -92,6 +96,13 @@ static int do_adc_single(struct cmd_tbl *cmdtp, int flag, int argc,
 	else
 		printf("%u\n", data);
 
+	if (varname) {
+		if (!adc_raw_to_uV(dev, data, &uV))
+			env_set_ulong(varname, uV);
+		else
+			env_set_ulong(varname, data);
+	}
+
 	return CMD_RET_SUCCESS;
 }
 
@@ -149,7 +160,7 @@ static int do_adc_scan(struct cmd_tbl *cmdtp, int flag, int argc,
 static char adc_help_text[] =
 	"list - list ADC devices\n"
 	"adc info <name> - Get ADC device info\n"
-	"adc single <name> <channel> - Get Single data of ADC device channel\n"
+	"adc single <name> <channel> [varname] - Get Single data of ADC device channel\n"
 	"adc scan <name> [channel mask] - Scan all [or masked] ADC channels";
 
 U_BOOT_CMD_WITH_SUBCMDS(adc, "ADC sub-system", adc_help_text,
-- 
2.35.1