physical: Conform to LED class kernel ABIHEADmaster

The kernel says the following about the LED sysfs interface:

> LED handling under Linux
> ========================
>
> In its simplest form, the LED class just allows control of LEDs from
> userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the
> LED is defined in max_brightness file. The brightness file will set the brightness
> of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware
> brightness support so will just be turned on for non-zero brightness settings.

The existing code assumed that max_brightness always held a value of
255 and defined a constant for it. Instead, use a class variable to
cache the max brightness for the associated LED.

Change-Id: I2d8f46de0cddac5f9d8ff5444449518bb4056130
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>

1 files changed, 3 insertions, 2 deletions

diff --git a/physical.cpp b/physical.cpp
index ae9ff1c..e614b99 100644
--- a/physical.cpp
+++ b/physical.cpp
@@ -27,6 +27,7 @@ namespace led
 /** @brief Populates key parameters */
 void Physical::setInitialState()
 {
+    assert = led.getMaxBrightness();
     auto trigger = led.getTrigger();
     if (trigger == "timer")
     {
@@ -44,7 +45,7 @@ void Physical::setInitialState()
 
         // Cache current LED state
         auto brightness = led.getBrightness();
-        if (brightness == ASSERT)
+        if (brightness == assert)
         {
             sdbusplus::xyz::openbmc_project::Led::server::Physical::state(
                 Action::On);
@@ -89,7 +90,7 @@ void Physical::driveLED(Action current, Action request)
 
 void Physical::stableStateOperation(Action action)
 {
-    auto value = (action == Action::On) ? ASSERT : DEASSERT;
+    auto value = (action == Action::On) ? assert : DEASSERT;
 
     led.setTrigger("none");
     led.setBrightness(value);