This patch adds dma mode support for rx and tx
with pio mode as fallback in case of dma error.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>