[U-Boot] [PATCH 4/9] A driver for the S6E63D6 SPI display controller from Samsung

Guennadi Liakhovetski lg at denx.de
Thu Feb 5 11:33:58 CET 2009


On Wed, 4 Feb 2009, Jean-Christophe PLAGNIOL-VILLARD wrote:

> On 17:59 Wed 04 Feb     , Guennadi Liakhovetski wrote:
> > +
> > +/*
> > + * Each transfer is performed as:
> > + * 1. chip-select active
> > + * 2. send 8-bit start code
> > + * 3. send 16-bit data
> > + * 4. chip-select inactive
> > + */
> > +static int send_word(struct spi_slave *spi, u8 rs, u16 data)
> > +{
> > +	u32 buf8 = 0x70 | ID | (rs & 2);
> why?

That's how the start byte looks like:

01110<ID><RS><R/W>

rs is 0 for index or 1 for data, and R/W is 0 for write.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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