ACPI: button: Refactor lid_init_state module parsing code

Replace the weird strncmp() calls in param_set_lid_init_state(),
which look to me like they will also accept things like "opennnn"
to use sysfs_match_string instead.

Also rewrite param_get_lid_init_state() using the new lid_init_state_str
array. Instead of doing a straightforward one line replacement, e.g. :
  return sprintf(buffer, lid_init_state_str[lid_init_state]);
print all possible values, putting [] around the selected value, so
that users can easily find out what the possible values are.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 4a2cde2c536a2ada6cec87147ce6d172ab50f94a..121d747a840c8c2d148cc4f8995d31bb7c405570 100644 (file)
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -44,9 +44,17 @@
 #define ACPI_BUTTON_DEVICE_NAME_LID    "Lid Switch"
 #define ACPI_BUTTON_TYPE_LID           0x05
 
-#define ACPI_BUTTON_LID_INIT_IGNORE    0x00
-#define ACPI_BUTTON_LID_INIT_OPEN      0x01
-#define ACPI_BUTTON_LID_INIT_METHOD    0x02
+enum {
+       ACPI_BUTTON_LID_INIT_IGNORE,
+       ACPI_BUTTON_LID_INIT_OPEN,
+       ACPI_BUTTON_LID_INIT_METHOD,
+};
+
+static const char * const lid_init_state_str[] = {
+       [ACPI_BUTTON_LID_INIT_IGNORE]           = "ignore",
+       [ACPI_BUTTON_LID_INIT_OPEN]             = "open",
+       [ACPI_BUTTON_LID_INIT_METHOD]           = "method",
+};
 
 #define _COMPONENT             ACPI_BUTTON_COMPONENT
 ACPI_MODULE_NAME("button");
@@ -578,36 +586,30 @@ static int acpi_button_remove(struct acpi_device *device)
 static int param_set_lid_init_state(const char *val,
                                    const struct kernel_param *kp)
 {
-       int result = 0;
-
-       if (!strncmp(val, "open", sizeof("open") - 1)) {
-               lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
-               pr_info("Notify initial lid state as open\n");
-       } else if (!strncmp(val, "method", sizeof("method") - 1)) {
-               lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
-               pr_info("Notify initial lid state with _LID return value\n");
-       } else if (!strncmp(val, "ignore", sizeof("ignore") - 1)) {
-               lid_init_state = ACPI_BUTTON_LID_INIT_IGNORE;
-               pr_info("Do not notify initial lid state\n");
-       } else
-               result = -EINVAL;
-       return result;
+       int i;
+
+       i = sysfs_match_string(lid_init_state_str, val);
+       if (i < 0)
+               return i;
+
+       lid_init_state = i;
+       pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
+       return 0;
 }
 
-static int param_get_lid_init_state(char *buffer,
-                                   const struct kernel_param *kp)
+static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
 {
-       switch (lid_init_state) {
-       case ACPI_BUTTON_LID_INIT_OPEN:
-               return sprintf(buffer, "open");
-       case ACPI_BUTTON_LID_INIT_METHOD:
-               return sprintf(buffer, "method");
-       case ACPI_BUTTON_LID_INIT_IGNORE:
-               return sprintf(buffer, "ignore");
-       default:
-               return sprintf(buffer, "invalid");
-       }
-       return 0;
+       int i, c = 0;
+
+       for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
+               if (i == lid_init_state)
+                       c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
+               else
+                       c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
+
+       buf[c - 1] = '\n'; /* Replace the final space with a newline */
+
+       return c;
 }
 
 module_param_call(lid_init_state,