From cd9b6fdf798841eb15253f928e762eee5260d347 Mon Sep 17 00:00:00 2001
From: Oskar Schirmer <os@emlix.com>
Date: Tue, 8 Jun 2010 01:12:22 -0700
Subject: [PATCH] Input: ad7877 - fix spi word size to 16 bit
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With no word size given in the users platform data, a generic spi host
controller driver will assume a default word size of eight bit. This
causes transmission to be performed bytewise, which will fail on little
endian machines for sure. Failure on big endian depends on usage
of slave select to mark word boundaries.
Anyway, ad7877 is specified to work with 16 bit per word, so
unconditionally set the word size accordingly. Flag an error where 16
bit per word is not available.
Signed-off-by: Oskar Schirmer <os@emlix.com>
Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Oliver Schneidewind <osw@emlix.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
drivers/input/touchscreen/ad7877.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c
index 0d2d7e54b465..5f0221cffef9 100644
--- a/drivers/input/touchscreen/ad7877.c
+++ b/drivers/input/touchscreen/ad7877.c
@@ -679,6 +679,13 @@ static int __devinit ad7877_probe(struct spi_device *spi)
return -EINVAL;
}
+ spi->bits_per_word = 16;
+ err = spi_setup(spi);
+ if (err) {
+ dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
+ return err;
+ }
+
ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
input_dev = input_allocate_device();
if (!ts || !input_dev) {