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From: Taras Kondratiuk <taras.kondratiuk-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Cc: Santosh Shilimkar
	<santosh.shilimkar-l0cyMroinI0@public.gmane.org>,
	patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
	linaro-networking-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
	linaro-kernel-cunTk1MwBs8s++Sfvej+rw@public.gmane.org,
	Sekhar Nori <nsekhar-l0cyMroinI0@public.gmane.org>,
	Kevin Hilman
	<khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>,
	davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org,
	linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH] i2c: davinci: raw read and write endian fix
Date: Wed, 20 Nov 2013 20:23:44 +0200	[thread overview]
Message-ID: <1384971824-7707-1-git-send-email-taras.kondratiuk@linaro.org> (raw)

I2C IP block expect LE data, but CPU may operate in BE mode.
Need to use endian neutral functions to read/write h/w registers.
I.e instead of __raw_read[lw] and __raw_write[lw] functions code
need to use read[lw]_relaxed and write[lw]_relaxed functions.
If the first simply reads/writes register, the second will byteswap
it if host operates in BE mode.

Changes are trivial sed like replacement of __raw_xxx functions
with xxx_relaxed variant.

Signed-off-by: Taras Kondratiuk <taras.kondratiuk-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
Based on Linus' master tip (b4789b8).
Tested on Keystone2 EVM.

 drivers/i2c/busses/i2c-davinci.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 132369f..a629447 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -125,12 +125,12 @@ static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
 static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
 					 int reg, u16 val)
 {
-	__raw_writew(val, i2c_dev->base + reg);
+	writew_relaxed(val, i2c_dev->base + reg);
 }
 
 static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
 {
-	return __raw_readw(i2c_dev->base + reg);
+	return readw_relaxed(i2c_dev->base + reg);
 }
 
 /* Generate a pulse on the i2c clock pin. */
-- 
1.7.9.5

             reply	other threads:[~2013-11-20 18:23 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-20 18:23 Taras Kondratiuk [this message]
     [not found] ` <1384971824-7707-1-git-send-email-taras.kondratiuk-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2013-11-21 17:05   ` [PATCH] i2c: davinci: raw read and write endian fix Grygorii Strashko
2013-11-26 12:39   ` Wolfram Sang
2013-11-27 18:29   ` Wolfram Sang

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