LED driver circuit with both analog and pwm control
You can just add the control to the amplifier:







simulate this circuit &ndash; Schematic created using CircuitLab

Some notes:


The input common mode range of the amplifier must go all the way to ground.
The PWM control is inverted: A high on the PWM input will turn the LED off.
The PWM rate will be limited by the transient performance of the amplifier.