[R] add value to Bar chart ggplot2

[chalabi.elahe at yahoo.de]

Hi all ,
I have the following bar chart and I want to add SLC variable values to the charts but I don't know how to use geom_text:
 
 
    ggplot(df,(Protocol,fill=quant))+geom_bar()+coord_flip()
 
Thanks for any help!
Elahe