From mboxrd@z Thu Jan 1 00:00:00 1970 From: rajeev kumar Subject: Re: [PATCH] i2c: i2c-bcm2708: fixes cdiv uneven number Date: Fri, 1 May 2015 10:54:48 +0530 Message-ID: References: <1430417266-14900-1-git-send-email-linux_wi@tinag.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1430417266-14900-1-git-send-email-linux_wi-ADq4ffItWIY@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Silvan Wicki Cc: Wolfram Sang , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Thu, Apr 30, 2015 at 11:37 PM, Silvan Wicki wrote: > 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; Use #define ~Rajeev > baudrate = bus_hz / cdiv; > + } else { > + if ((cdiv & 0xfffe) != cdiv) { > + cdiv &= 0xfffe; > + baudrate = bus_hz / cdiv; > + } > } > bi->cdiv = cdiv; > > -- > 2.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html