[PATCH v2] cmd: adc: Add support for storing ADC result in env variable

[Marek Vasut]

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

Signed-off-by: Marek Vasut <ma...@denx.de>
Cc: Fabrice Gasnier <fabrice.gasn...@foss.st.com>
Cc: Patrice Chotard <patrice.chot...@foss.st.com>
Cc: Patrick Delaunay <patrick.delau...@foss.st.com>
Cc: Simon Glass <s...@chromium.org>
---
V2: - Fix up commit message
    - Call adc_raw_to_uV() only once
---
 cmd/adc.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/cmd/adc.c b/cmd/adc.c
index 75739bc8eed..8de9121cad6 100644
--- a/cmd/adc.c
+++ b/cmd/adc.c
@@ -71,13 +71,17 @@ 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;
+       int ret, uV, val;
 
        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) {
@@ -87,10 +91,16 @@ static int do_adc_single(struct cmd_tbl *cmdtp, int flag, 
int argc,
        }
 
        ret = uclass_get_device_by_name(UCLASS_ADC, argv[1], &dev);
-       if (!ret && !adc_raw_to_uV(dev, data, &uV))
+       if (!ret && !adc_raw_to_uV(dev, data, &uV)) {
+               val = uV;
                printf("%u, %d uV\n", data, uV);
-       else
+       } else {
+               val = data;
                printf("%u\n", data);
+       }
+
+       if (varname)
+               env_set_ulong(varname, val);
 
        return CMD_RET_SUCCESS;
 }
@@ -149,7 +159,7 @@ 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