tree a40b0732817ad289b9b1e0785aaa1edacf3442f4
parent f09978566b601a6377dfe56dd11da0df75ba9fd0
author Weijie Gao <weijie.gao@mediatek.com> 1569404724 +0800
committer Daniel Schwierzeck <daniel.schwierzeck@gmail.com> 1572016844 +0200

spi: mt7621-spi: remove data cache and rewrite its xfer function

The mt7621 spi controller supports continuous generic half-duplex spi
transaction. There is no need to cache xfer data at all.

To achieve this goal, the OPADDR register must be used as the first data
to be sent. And follows the eight generic DIDO registers. But one thing
different between OPADDR and DIDO registers is OPADDR has a reversed byte
order.

With this patch, any amount of data can be read/written in a single xfer
function call.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>