From mboxrd@z Thu Jan 1 00:00:00 1970 From: Silvan Wicki Subject: [PATCH] i2c: i2c-bcm2708: fixes cdiv uneven number Date: Thu, 30 Apr 2015 20:07:46 +0200 Message-ID: <1430417266-14900-1-git-send-email-linux_wi@tinag.ch> Return-path: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Silvan Wicki List-Id: linux-i2c@vger.kernel.org Prevents that cdiv can be an uneven number as per datasheet cdiv is always rounded down to an even number. Datasheet at page 34 on http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf Signed-off-by: Silvan Wicki --- drivers/i2c/busses/i2c-bcm2708.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-bcm2708.c b/drivers/i2c/busses/i2c-bcm2708.c index 81e9374..454ab48 100644 --- a/drivers/i2c/busses/i2c-bcm2708.c +++ b/drivers/i2c/busses/i2c-bcm2708.c @@ -441,9 +441,15 @@ static int bcm2708_i2c_probe(struct platform_device *pdev) bus_hz = clk_get_rate(bi->clk); cdiv = bus_hz / baudrate; - if (cdiv > 0xffff) { - cdiv = 0xffff; + /* as per datasheet cdiv is always rounded down to an even number */ + if (cdiv > 0xfffe) { + cdiv = 0xfffe; baudrate = bus_hz / cdiv; + } else { + if ((cdiv & 0xfffe) != cdiv) { + cdiv &= 0xfffe; + baudrate = bus_hz / cdiv; + } } bi->cdiv = cdiv; -- 2.1.4