[PATCH v4 4/4] platform/x86: think-lmi: Add possible_values for ThinkStation

[Mark Pearson]

ThinkStation platforms don't support the API to return possible_values
but instead embed it in the settings string.

Try and extract this information and set the possible_values attribute
appropriately.

Signed-off-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
---
Changes in v4:
 - is_visible handling split out into separate patch
 - linelength reduced so checkpatch is clean.
Changes in v3:
 - Use is_visible attribute to determine if possible_values should be
   available
 - Code got refactored a bit to make compilation cleaner
Changes in v2:
 - Move no value for possible_values handling into show function
 - use kstrndup for allocating string

 drivers/platform/x86/think-lmi.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 6f8c91716a95..aaaeb30fb0b0 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -1422,6 +1422,26 @@ static int tlmi_analyze(void)
 			if (ret || !setting->possible_values)
 				pr_info("Error retrieving possible values for %d : %s\n",
 						i, setting->display_name);
+		} else {
+			/*
+			 * Older Thinkstations don't support the bios_selections API.
+			 * Instead they store this as a [Optional:Option1,Option2] section of the
+			 * name string.
+			 * Try and pull that out if it's available.
+			 */
+			char *item, *optstart, *optend;
+
+			if (!tlmi_setting(setting->index, &item, LENOVO_BIOS_SETTING_GUID)) {
+				optstart = strstr(item, "[Optional:");
+				if (optstart) {
+					optstart += strlen("[Optional:");
+					optend = strstr(optstart, "]");
+					if (optend)
+						setting->possible_values =
+							kstrndup(optstart, optend - optstart,
+									GFP_KERNEL);
+				}
+			}
 		}
 		/*
 		 * firmware-attributes requires that possible_values are separated by ';' but
-- 
2.39.2