There are four CPU clock post dividers:
- ABP
- PERIPH (used for the ARM global timer and ARM TWD timer)
- AXI
- L2 DRAM
Each of these clocks consists of two clocks:
- a mux to select between "cpu_clk" divided by 2, 3, 4, 5, 6, 7 or 8
- a "_clk_dis" gate. The public S805 datasheet states that this should
be set to 1 to disable the clock, the default value is 0. There is
also a hint that these are "just in case" bits which only exist in
case the corresponding mux implementation does not allow glitch-free
parent changes (the muxes are designed in a way that the clock can
stay enabled when changing the mux). It's still good practise to
describe this clock even if we're not supposed to modify it. Thus
this uses the read-only gate ops.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181122214017.25643-5-martin.blumenstingl@googlemail.com
The "cpu_div2" and "cpu_div3" take "cpu_in" as input and divide that by
2 or 3. The clock controller can also generate various CPU clock
post-dividers (2, 3, 4, 5, 6, 7, 8) which are derived from "cpu_clk".
When adding support for these post-dividers our clock naming could be
misleading as we have "cpu_div2" as well as "cpu_clk_div2".
Rename the existing "cpu_in" dividers so the name of the divider's
parent is part of the divider clock's name.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181122214017.25643-4-martin.blumenstingl@googlemail.com
Remove od parameters from pll clocks and add post dividers clocks
instead. Some clock, especially the one which feature several ods,
may provide output between those ods. Also, some drivers, such
as the hdmi driver, may require a more detailed control of the
clock dividers, compared to what CCF would perform automatically.
One added benefit of removing ods is that it also greatly reduce the
size of the rate parameter tables.
In the future, we could possibly take the predivider 'n' out of this
driver as well. To do so, we will need to understand the constraints
for the PLL to lock and whether or not it depends on the input clock
rate.
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Replace every license notices in drivers/clk/meson by SPDX license
identifiers, as described in license-rules.rst
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
This adds the NAND clocks (from the HHI_NAND_CLK_CNTL register) to the
Meson8b clock driver. There are three NAND clocks: a gate which enables
or disables the NAND clock, a mux and a divider (which divides the mux
output).
Unfortunately the public S805 datasheet does not document the mux
parents. However, the vendor kernel has a few hints for us which allows
us to make an educated guess about the clock parents. To do this we need
to have a look at set_nand_core_clk() from the vendor's NAND driver (see
[0]):
- XTAL = (4<<9) | (1<<8) | 0
- 160MHz = (0<<9) | (1<<8) | 3)
- 182MHz = (3<<9) | (1<<8) | 1)
- 212MHz = (1<<9) | (1<<8) | 3)
- 255MHz = (2<<9) | (1<<8) | 1)
While there is a comment for the XTAL parent (which indicates that it
should only be used for debugging) we have to do a bit of math for the
other parents: target_freq * divider = rate of parent clock
Bit 8 above is the enable bit, so we can ignore it here. Bits 11:9 are
the mux index and bits 6:0 are the 0-based divider (so we need to add
1). This gives us:
- mux 0 (160MHz * 4) = fclk_div4 (actual rate = 637.5MHz, off by 2.5MHz)
- mux 1 (212MHz * 4) = fclk_div3 (actual rate = 850MHz, off by 2MHz)
- mux 2 (255MHz * 2) = fclk_div5 (matches exactly 510MHz)
- mux 3 (182MHz * 2) = fclk_div7 (actual rate = 346.3MHz, off by 0.3MHz)
[0] https://github.com/khadas/linux/blob/9587681285cb/drivers/amlogic/amlnf/dev/amlnf_ctrl.c#L314
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Fdiv fixed dividers clocks of the fixed_pll can actually gate
independently. We never had an issue so far because these clocks
were provided 'enabled' by the bootloader.
Add these gates to enable/disable the clocks when required.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
mpll clocks parent can actually be divided by 1 or 2. So far, this
divider has always been set to 1, so the calculation was correct.
Now that we know it exists, model the tree correctly. If we ever get
a platform where the divider is different, we won't get into trouble
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Instead of migrating meson cpu_clk to clk_regmap, like the other meson
clock drivers, we take advantage of the massive rework to get rid of it
completely, and solve (the first part) of the related FIXME notice.
As pointed out in the code comments, the cpu_clk should be modeled with
dividers and muxes it is made of, instead of one big composite clock.
The cpu_clk was not working correctly to enable dvfs on meson8b. It hangs
quite often when changing the cpu clock rate. This new implementation,
based on simple elements improves the situation but the platform will
still hang from time to time. This is not acceptable so, until we can
make the mechanism around the cpu clock stable, the cpu clock subtree
has been put in read-only mode, preventing any change of the cpu clock
The notifier and read-write operation will be added back when we have a
solution to the problem.
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
The mpll clock is a kind of fractional divider which can gate.
When the RW operation have been added, enable/disable ops have been
mistakenly inserted in this driver. These ops are essentially a
poor copy/paste of the generic gate ops.
This change removes the gate ops from the mpll driver and inserts a
generic gate clock on each mpll divider, simplifying the mpll
driver and reducing code duplication.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
The clock controller also includes some reset lines. This patch
implements a reset controller to assert and de-assert these resets.
The reset controller itself is registered early (through
CLK_OF_DECLARE_DRIVER) because it is needed very early in the boot
process (to start the secondary CPU cores).
According to the public S805 datasheet there are two more reset bits
in the HHI_SYS_CPU_CLK_CNTL0 register, which are not implemented by
this patch (as these seem to be unused in Amlogic's vendor Linux kernel
sources and their u-boot tree):
- bit 15: GEN_DIV_SOFT_RESET
- bit 14: SOFT_RESET
All information was taken from the public S805 Datasheet and Amlogic's
vendor GPL kernel sources. This patch is based on an earlier version
submitted by Carlo Caione.
Suggested-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Expose all clocks which maybe used as DT bindings
Only clock ids internal the controller remain un-exposed (none on this
particular controller at the moment)
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Export the ethernet gate clock to the dt-bindings.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Export the USB related clocks (for the USB controller and the USB2 PHYs)
so they can be used in the dt-bindings.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
This exports the clock so it can be used in the dt-bindings.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Export the SDIO clock so it can be used in the dt-bindings.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Export the clocks for the SAR ADC so they can be used in the
dt-bindings.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
This patch adds support for the meson8b clock gates. Most of
them are disabled by Amlogic U-Boot, but need to be enabled
for ethernet, USB and many other components.
Signed-off-by: Alexander Müller <serveralex@gmail.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1472319654-59048-7-git-send-email-serveralex@gmail.com
Only expose future CLKID constants if necessary. This patch
removes CLK_NR_CLKS from the DT bindings but leaves all previously
defined CLKIDs there to keep backward compatibility.
Signed-off-by: Alexander Müller <serveralex@gmail.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1472319654-59048-5-git-send-email-serveralex@gmail.com
Martin Blumenstingl