Using the fractional dividers requires some additional power bits to be
set.
The fractional power bits are not documented and the current heuristic
for setting them seems be insufficient for some cases. Just always set all
the fractional power bits when in fractional mode.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201001085948.21412-2-alexandru.ardelean@analog.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The axi-clkgen has (optional) fractional dividers on the output clock
divider and feedback clock divider path. Utilizing the fractional dividers
allows for a better resolution of the output clock, being able to
synthesize more frequencies.
Rework the driver support to support the fractional register fields, both
for setting a new rate as well as reading back the current rate from the
hardware.
For setting the rate if no perfect divider settings were found in
non-fractional mode try again in fractional mode and see if better settings
can be found. This appears to be the recommended mode of operation.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201001085948.21412-1-alexandru.ardelean@analog.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Based on 1 normalized pattern(s):
licensed under the gpl 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 135 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.071193225@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To minimize the rounding error round to the closest integer when
calculating the result in the recalc_rate() and set_rate() callbacks.
Also in order to improve precision multiply first and then divide.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
If the nocount bit is set the divider is bypassed and the settings for the
divider count should be ignored and a divider value of 1 should be assumed.
Handle this correctly in the driver recalc_rate() callback.
While the driver sets up the part so that the read back dividers values
yield the correct result the power-on reset settings of the part might not
reflect this and hence calling e.g. clk_get_rate() without prior calls to
clk_set_rate() will yield the wrong result.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers while registering clks in
these drivers, allowing us to move closer to a clear split of
consumer and provider clk APIs.
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The size of unsigned long on 64-bit architectures is equal to the
size of u64, so this check is impossible there. This throws off
static checkers:
drivers/clk/clk-axi-clkgen.c:331 axi_clkgen_recalc_rate() warn:
impossible condition '(tmp > (~0)) => (0-u64max > u64max)'
Let's change this code to use min_t() instead so that we
get the same effect on architectures where sizeof(unsigned long)
doesn't equal sizeof(u64).
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The clock generator has two clock inputs that can be used as the reference
clock. Add support for switching between them at runtime.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Version 1 of the axi-clkgen core has not been used in new designs for over
two years now. This is a soft peripheral used in FPGAs and anybody who has
updated their kernel to the latest version will also have updated the
bitstream containing the clock generator. So it should be safe to drop
support for this now.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Clock provider drivers generally shouldn't include clk.h because
it's the consumer API. Remove the include here because this is a
provider driver.
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
There is no need to init .owner field.
Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"
This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."
Signed-off-by: Kiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This patch adds support for the new v2 version of the axi-clkgen core.
Unfortunately the method of accessing the registers is quite different on v2,
while the content still stays largely the same. So the patch adds a small
abstraction layer which implements the specific read and write functions for v1
and v2 in callback functions.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This driver adds support for the AXI clkgen pcore to the common clock framework.
The AXI clkgen pcore is a AXI front-end to the MMCM_ADV frequency synthesizer
commonly found in Xilinx FPGAs.
The AXI clkgen pcore is used in Analog Devices' reference designs targeting
Xilinx FPGAs.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
