Re: [PATCH] input/spi: add ads7843 support to ads7846 touchscreen driver

From: Nicolas Ferre
Date: Thu Dec 21 2006 - 08:10:41 EST


David Brownell a écrit :
On Friday 15 December 2006 7:20 am, Nicolas FERRE wrote:
Add support for the ads7843 touchscreen controller to the ads7846 driver code.

Glad to see this! Is this for AT91sam9261-EK board support, maybe?

Indeed ! An also for the AT91sam9263-EK which has the same touchscreen chip.

Let me try to sort out the mess with those updates, and ask you to refresh
this ads7843 support against that more-current ads7846 code.

Ok, let me know when you have a newer code. I will try to adapt my
ads7843 support then.

As the SPI underlying code behaves quite differently from a controller driver
to another whan not having a tx_buf filled, I have add a zerroed buffer to give
to the spi layer while receiving data.

You must be working with a buggy controller driver then. That part of
this patch should never be needed. It's expected that rx-only transfers
will omit a tx buf; all controller drivers must handle that case.

I said that because it is true that most of spi controller drivers manage rx only transactions filling the tx buffer with zerros but the spi_s3c24xx.c driver seems to fill with ones (line 177 hw_txbyte())

Anyway, I will check in our controller driver to sort this out.

Regards,
--
Nicolas Ferre



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/