clk: mxs: Invalid register access on HW_CLKCTRL_FRAC0?
Uwe Kleine-König
u.kleine-koenig at pengutronix.de
Sat Dec 13 12:36:16 PST 2014
On Sat, Dec 13, 2014 at 01:23:29PM +0100, Stefan Wahren wrote:
> Hi Fabio,
>
> yesterday i stumble on this note in the i.MX28 reference manual (p. 931):
(when talking page numbers it's usually helpful to also specify the
document more exactly. I use "i.MX28 Applications Processor Reference
Manual Rev2, 08/2013", the page number seems to match.)
> 10.8.24 Fractional Clock Control Register 0 (HW_CLKCTRL_FRAC0)
>
> NOTE: This register can only be addressed by byte instructions. Addressing
> word or half-word are not allowed.
>
> The same applies to HW_CLKCTRL_FRAC1.
Bah, looking at the example code for this register:
*((u8 *)(HW_CLKCTRL_FRAC0_ADDR + 1)) = 30;
without any further comment. The documentation writes could at least
have added:
Assuming little endian operation this command sets EMIFRAC=0x1e
and CLKGATEEMI=0.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
More information about the linux-arm-kernel
mailing list