Since the dawn of time the ICST code has only supported divide
by one or hang in an eternal loop. Luckily we were always dividing
by one because the reference frequency for the systems using
the ICSTs is 24MHz and the [min,max] values for the PLL input
if [10,320] MHz for ICST307 and [6,200] for ICST525, so the loop
will always terminate immediately without assigning any divisor
for the reference frequency.
But for the code to make sense, let's insert the missing i++
Reported-by: David Binderman <dcb314@hotmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When trying to set the ICST 307 clock to 25174000 Hz I ran into
this arithmetic error: the icst_hz_to_vco() correctly figure out
DIVIDE=2, RDW=100 and VDW=99 yielding a frequency of
25174000 Hz out of the VCO. (I replicated the icst_hz() function
in a spreadsheet to verify this.)
However, when I called icst_hz() on these VCO settings it would
instead return 4122709 Hz. This causes an error in the common
clock driver for ICST as the common clock framework will call
.round_rate() on the clock which will utilize icst_hz_to_vco()
followed by icst_hz() suggesting the erroneous frequency, and
then the clock gets set to this.
The error did not manifest in the old clock framework since
this high frequency was only used by the CLCD, which calls
clk_set_rate() without first calling clk_round_rate() and since
the old clock framework would not call clk_round_rate() before
setting the frequency, the correct values propagated into
the VCO.
After some experimenting I figured out that it was due to a simple
arithmetic overflow: the divisor for 24Mhz reference frequency
as reference becomes 24000000*2*(99+8)=0x132212400 and the "1"
in bit 32 overflows and is lost.
But introducing an explicit 64-by-32 bit do_div() and casting
the divisor into (u64) we get the right frequency back, and the
right frequency gets set.
Tested on the ARM Versatile.
Cc: stable@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The patch below updates broken web addresses in the arch directory.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The only difference between ICST307 and ICST525 are the two arrays
for calculating the S parameter; the code is now identical. Merge
the two files and kill the duplicated code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
