| Age | Commit message (Collapse) | Author |
|---|
|
pllv4 is designed for System Clock Generation (SCG) module observed
in IMX ULP SoC series. e.g. i.MX7ULP.
The SCG modules generates clock used to derive processor, system,
peripheral bus and external memory interface clocks while this patch
intends to support the PLL part.
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Anson Huang <Anson.Huang@nxp.com>
Cc: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
[sboyd@kernel.org: Include clk.h for sparse warnings]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Adding CLK_FRAC_DIVIDER_ZERO_BASED flag to indicate the numerator and
denominator value in register are start from 0.
This can be used to support frac dividers like below:
Divider output clock = Divider input clock x [(frac +1) / (div +1)]
where frac/div in register is:
000b - Divide by 1.
001b - Divide by 2.
010b - Divide by 3.
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
For dividers with zero indicating clock is disabled, instead of giving a
warning each time like "clkx: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not
set" in exist code, we'd like to introduce enable/disable function for it.
e.g.
000b - Clock disabled
001b - Divide by 1
010b - Divide by 2
...
Set rate when the clk is disabled will cache the rate request and only
when the clk is enabled will the driver actually program the hardware to
have the requested divider value. Similarly, when the clk is disabled we'll
write a 0 there, but when the clk is enabled we'll restore whatever rate
(divider) was chosen last.
It does mean that recalc rate will be sort of odd, because when the clk is
off it will return 0, and when the clk is on it will return the right rate.
So to make things work, we'll need to return the cached rate in recalc rate
when the clk is off and read the hardware when the clk is on.
NOTE for the default off divider, the recalc rate will still return 0 as
there's still no proper preset rate. Enable such divider will give user
a reminder error message.
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
[sboyd@kernel.org: Include clk.h for sparse warnings]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The SCCG is a new PLL type introduced on i.MX8.
The description of this SCCG clock can be found here:
https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
This is a new fractional clock type introduced on i.MX8.
The description of this fractional clock can be found here:
https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Add driver for the Clock Control Module found on i.MX8MQ.
Signed-off-by: Anson Huang <anson.huang@nxp.com>
Signed-off-by: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Since a lot of clocks on imx8m are formed by a mux, gate, predivider and
divider, the idea here is to combine all of those into one composite clock,
but we need to deal with both predivider and divider at the same time and
therefore we add the imx8m_clk_composite_divider_ops and register
the composite clock with those.
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Suggested-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The offsets for the defined BCR reset registers does not match the hardware
documentation. Update the values to match the hardware documentation.
Fixes: b5f5f525c547 (clk: qcom: Add MSM8998 Global Clock Control (GCC) driver)
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The > comparison should be >= to prevent reading beyond the end of the
clock[] array.
(The clock[] array is allocated in zynqmp_clk_setup() and has
clock_max_idx elements.)
Fixes: 3fde0e16d016 ("drivers: clk: Add ZynqMP clock driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The > comparison should be >= or we write one element beyond the end of
the unit->clk_table[] array.
(The unit->clk_table[] array is allocated in the mmp_clk_init() function
and it has unit->nr_clks elements).
Fixes: 4661fda10f8b ("clk: mmp: add basic support functions for DT support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
These > comparisons should be >= to prevent reading beyond the end of
of the clk_data->hws[] buffer.
The clk_data->hws[] array is allocated in cp110_syscon_common_probe()
when we do:
cp110_clk_data = devm_kzalloc(dev, sizeof(*cp110_clk_data) +
sizeof(struct clk_hw *) * CP110_CLK_NUM,
GFP_KERNEL);
As you can see, it has CP110_CLK_NUM elements which is equivalent to
CP110_MAX_CORE_CLOCKS + CP110_MAX_GATABLE_CLOCKS.
Fixes: d3da3eaef7f4 ("clk: mvebu: new driver for Armada CP110 system controller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Add support for the lpass clock controller found on SDM845 based devices.
This would allow lpass peripheral loader drivers to control the clocks to
bring the subsystem out of reset.
LPASS clocks present on the global clock controller would be registered
with the clock framework based on the protected-clock flag. Also do not
gate these clocks if they are left unused, as the lpass clocks require
the global clock controller lpass clocks to be enabled before they are
accessed. Mark the GCC lpass clocks as CRITICAL, for the LPASS clock
access.
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The third parent of CSI_MCLK is PLL_PERIPH1, not PLL_PERIPH0.
Fix it.
Fixes: 0577e4853bfb ("clk: sunxi-ng: Add H3 clocks")
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
|
|
Add all clocks to give us the final video clocks within the Meson8,
Meson8b and Meson8m2 SoCs. The final video clocks are:
- cts_enct
- cts_encl
- cts_encp
- cts_enci
- cts_vdac0
- hdmi_tx_pixel
- hdmi_sys
Add multiple clocks in between which are needed to implement these
clocks:
- Opposed to GXBB there is no pre-multiplier for the PLL input. The
assumption here is that the multiplier is required to achieve the HDMI
2.0 clock rates (which are up to twice the rate of the HDMI 1.4
rates).
- The main PLL is called "HDMI PLL" or "HPLL" in the datasheet. Rename
our existing "vid_pll_dco" to "hdmi_pll_dco". The actual VID_PLL clock
also exists further down the tree.
- Rename the existing "vid_pll" clock (which is the OD divider at
HHI_VID_PLL_CNTL[17:16]) to "hdmi_pll_lvds_out" to match the naming
from the datasheet.
- Add the second OD divider called "hdmi_pll_hdmi_out" at
HHI_VID_PLL_CNTL[19:18].
- Add the "vid_pll_in_sel" which can choose between "hdmi_pll_dco" and
another parent. However, the second parent is not use on Amlogic's
3.10 kernel for HDMI or CVBS output so just leave a TODO in the code.
- Add the "vid_pll_in_en" which is located after "vid_pll_in_sel"
according to the datasheet.
- Add "vid_pll_pre_div" which is used for divide-by-5 and divide-by-6 in
Amlogic's 3.10 kernel sources.
- Add "vid_pll_post_div" which divides the output of "vid_pll_pre_div"
further down. The Amlogic 3.10 kernel configures this as divide-by-2
with "vid_pll_pre_div" being configured as divide-by-5 to achieve a
total divider of 10.
- Add the real "vid_pll" clock which selects between "vid_pll_pre_div",
"vid_pll_post_div" and a third "vid_pll_pre_div_mult7_div2" (which is
"vid_pll_pre_div" divided by 3.5). The latter is not supported yet
because it's not used in Amlogic's 3.10 kernel. The "vid_pll" clock
rate can also be measured by clkmsr to check whether this
implementation is correct.
- Add "vid_pll_final_div" which is a post-divider for "vid_pll" and it's
used as input for "vclk" and "vclk2"
- Add the two symmetric "vclk" and "vclk" clock trees, each with a
divide-by-1, divide-by-2, divide-by-4, divide-by-6 and divide-by-12
clock and a divider for each clock.
- Add the "cts_enct", "cts_encp" and "hdmi_tx_pixel" clocks which each
have their own gate and can select between any of the five "vclk"
dividers.
- Add the "cts_encl" and "cts_vdac0" clocks which each have their own
gate and can select between any of the five "vclk2" dividers.
The "hdmi_sys" clock is a different than these video clocks. It takes
"xtal" as input (there are three more but unknown parents). Add this
clock as well as it's used by the HDMI controller. Amlogic's 3.10 kernel
always configures this as "xtal divided by 1", so we can ignore the
other parents for now.
This was tested on Meson8b and Meson8m2 boards by comparing the common
clock framework output with the clock measurer output. The following
video modes were first set in u-boot (by running "video dev open $mode")
before booting Linux:
4K2K30HZ (only supported by Meson8m2, not tested on Meson8b):
- vid_pll: 297000000Hz
- cts_encp: 297000000Hz
- hdmi_tx_pixel: 297000000Hz
1080P:
- vid_pll: 148500000Hz
- cts_encp: 148500000Hz
- hdmi_tx_pixel: 148500000Hz
720P:
- vid_pll: 148500000Hz
- cts_encp: 148500000Hz
- hdmi_tx_pixel: 74250000Hz
480P:
- vid_pll: 216000000Hz
- cts_encp: 54000000Hz
- hdmi_tx_pixel: 27000000Hz
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181202214220.7715-4-martin.blumenstingl@googlemail.com
|
|
This "vid_pll_dco" (which should be named HDMI_PLL or - as the datasheet
calls it - HPLL) has a 12-bit wide fractional parameter at
HHI_VID_PLL_CNTL2[11:0]. Add this so we correctly calculate the rate of
this PLL when u-boot is configured for a video mode which uses this
fractional parameter.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181202214220.7715-3-martin.blumenstingl@googlemail.com
|
|
Unlike the other PLLs on Meson8b the N value "vid_pll_dco" (a better
name would be hdmi_pll_dco or - as the datasheet calls it - HPLL) is
located at HHI_VID_PLL_CNTL[14:10] instead of [13:9].
This results in an incorrect calculation of the rate of this PLL because
the value seen by the kernel is double the actual N (divider) value.
Update the offset of the N value to fix the calculation of the PLL rate.
Fixes: 28b9fcd016126e ("clk: meson8b: Add support for Meson8b clocks")
Reported-by: Jianxin Pan <jianxin.pan@amlogic.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181202214220.7715-2-martin.blumenstingl@googlemail.com
|
|
Add SPI friendly clock rates to the spi freq table.
Today it's not possible to use SPI at lower than 960Khz.
This patch adds 100/250/500/1000 kHz configs to the table.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
This function is called from driver probe, which isn't the same as
__init code because driver probe can happen later. Drop the __init
marking here to fix this potential problem.
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Wenzhen Yu <wenzhen.yu@mediatek.com>
Cc: Weiyi Lu <weiyi.lu@mediatek.com>
Fixes: 2fc0a509e4ee ("clk: mediatek: add clock support for MT7622 SoC")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
This function is used from more places than just __init code. Removing
__init silences a section mismatch warning here.
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Wenzhen Yu <wenzhen.yu@mediatek.com>
Cc: Weiyi Lu <weiyi.lu@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
There is no need to have the 'struct clk_hw **hws' variable static
since new value always be assigned before use it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Add all supported clocks exported from every susbystem found on MT7629 SoC.
Signed-off-by: Wenzhen Yu <wenzhen.yu@mediatek.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
On the R40, in addition to a mux between the RTC's own RC oscillator and
an external 32768 Hz crystal, which are muxed inside the RTC module, the
CCU also has its own RC oscillator, which runs at around 2 MHz, and can
be muxed with the LOSC output from the RTC. This muxed output is called
"SYS 32K" in the module clock diagram, but otherwise referred to as the
LOSC throughout the CCU documentation.
The RC oscillator is not very accurate, even though it has an undocumented
calibration function. We really want a precise clock at 32768 Hz,
instead of something at around 32 KHz. This patch forces the SYS 32K
clock to use the RTC output as its parent, and doesn't bother
registering the internal oscillator nor a clock mux.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
|
|
This is only used in this file, so mark it static to silence a sparse
warning.
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Use macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Use macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
[sboyd@kernel.org: Rename show function to keep compiling]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
In an earlier version of commit 453361cdd757 ("clk: qcom: Add graphics
clock controller driver for SDM845") there were 6 listed parents for
"gpu_cc_gmu_clk_src". In the version that landed there were 5.
...but "num_parents" was still left at 6. On my system this goes boom
at bootup.
Fixes: 453361cdd757 ("clk: qcom: Add graphics clock controller driver for SDM845")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
* clk-protected-binding:
clk: qcom: Support 'protected-clocks' property
dt-bindings: clk: Introduce 'protected-clocks' property
|
|
Most of the time the CPU should not be touching the GX
domain on the GPU except for a very special use case when
the CPU needs to force the GX headswitch off. Add a
dummy enable function for the GX gdsc to simulate success
so that the pm_runtime reference counting is correct.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
In extreme cases an individual gdsc may wish to override the
power domain enable or disable callback functions for their own
purposes. Only set the generic gdsc callback if the function pointers
are not already set.
Acked-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
Add support for the graphics clock controller found on SDM845
based devices. This would allow graphics drivers to probe and
control their clocks.
Signed-off-by: Amit Nischal <anischal@codeaurora.org>
Signed-off-by: Taniya Das <tdas@codeaurora.org>
[sboyd@kernel.org: Collapse return in probe into less lines]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
The GXL Documentation specifies 12 bits for the Fractional bit field,
bit the last bits have a different purpose that we cannot handle right
now, so update the bitwidth to have correct fractional calculations.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[narmstrong: added comment on GXL HHI_HDMI_PLL_CNTL register shift]
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lkml.kernel.org/r/20181121111922.1277-1-narmstrong@baylibre.com
|
|
Add the newly added clock-id for PCLK_ACODECPHY to the gate-clock,
so that it gets usable from devicetree.
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
|
|
The audio blocks require specific clock rates. Until now we were using
the closest clock rate possible with integer N-M factors. This resulted
in audio playback being slightly slower than it should be.
The vendor kernel gets around this (for some SoCs) by using sigma-delta
modulation to generate a fractional-N factor. As the PLL hardware is
identical in most chips, we can port the settings for H3 onto the A64.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
|
|
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
|
|
Some of the gate clocks are described as "just in case" bits in the
datasheet. Examples are the ABP, PERIPH, AXI and L2 DRAM clocks on
Meson8b.
The datasheet suggests that these bits are not touched. The full
explanation is:
"Set to 1 to manually disable the [...] clock when changing the mux
selection. Typically this bit is set to 0 since the clock muxes can
switch without glitches.".
This adds new read-only ops for gate clocks so we can describe these
clocks in our clock controller drivers while ensuring that we can't
accidentally modify the registers.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181122214017.25643-3-martin.blumenstingl@googlemail.com
|
|
Currently all clocks in the CPU clock tree are marked as read-only
(using the corresponding _ro_ clk_ops). This was correct since changing
the clock tree could cause the system to lock up.
Switch all clocks to their corresponding clk_ops variant which is not
read-only to allow changing the CPU clock tree since the bug which
locked up the system is now fixed (by switching the CPU clock temporary
to run off XTAL while changing the CPU clock tree).
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181115224048.13511-7-martin.blumenstingl@googlemail.com
|
|
Changing the CPU clock requires changing various clocks including the
SYS PLL. The existing meson clk-pll and clk-regmap drivers can change
all of the relevant clocks already.
However, changing for exampe the SYS PLL is problematic because as long
as the CPU is running off a clock derived from SYS PLL changing the
latter results in a full system lockup.
Fix this system lockup by switching the CPU clock to run off the XTAL
while we are changing the any of the clocks in the CPU clock tree.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181115224048.13511-6-martin.blumenstingl@googlemail.com
|
|
The sys_pll on the EC-100 board is configured to 1584MHz at boot
(either by u-boot, firmware or chip defaults). This is achieved by using
M = 66, N = 1 (24MHz * 66 / 1).
At boot the CPU clock is running off sys_pll divided by 2 which results
in 792MHz. Thus M = 66 is considered to be a "safe" value for Meson8b.
To achieve 1608MHz (one of the CPU OPPs on Meson8 and Meson8m2) we need
M = 67, N = 1. I ran "stress --cpu 4" while infinitely cycling through
all available frequencies on my Meson8m2 board and could not spot any
issues with this setting (after ~12 hours of running this).
On Meson8, Meson8b and Meson8m2 we also want to be able to use 408MHz
and 816MHz CPU frequencies. These can be achieved by dividing sys_pll by
4 (for 408MHz) or 2 (for 816MHz). That means that sys_pll has to run at
1632MHz which can be generated using M = 68, N = 1.
Similarily we also want to be able to use 1008MHz as CPU frequency. This
means that sys_pll has to run either at 1008MHz or 2016MHz. The former
would result in an M value of 42, which is lower than the smallest value
used by the 3.10 GPL kernel sources from Amlogic (50 is the lower limit
there). Thus we need to run sys_pll at 2016MHz which can ge generated
using M = 84, N = 1.
I tested M = 68 and M = 84 on my Meson8b Odroid-C1 and my Meson8m2 board
by running "stress --cpu 4" while infinitely cycling thorugh all
available frequencies. I could not spot any issues after ~12 hours of
running this.
Amlogic's 3.10 GPL kernel sources have more M/N combinations. I did not
add them yet because M = 74 (to achieve close to 1800MHz on Meson8) and
M = 82 (to achieve close to 1992MHz on Meson8 as well) caused my
Meson8m2 board to hang randomly. It's not clear why this is (for example
because the board's voltage regulator design is bad, some missing bits
for these values in our clk-pll driver, etc.). Thus the following M
values from the Amlogic 3.10 GPL kernel sources are skipped as of now:
69, 70, 71, 72, 73, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98
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/20181115224048.13511-5-martin.blumenstingl@googlemail.com
|
|
We don't want the common clock framework to disable the "cpu_clk" if
it's not used by any device. The cpufreq-dt driver does not enable the
CPU clocks. However, even if it would we would still want the CPU clock
to be enabled at all times because the CPU clock is also required even
if we disable CPU frequency scaling on a specific board.
The reason why we want the CPU clock to be enabled is a clock further up
in the tree:
Since commit 6f888e7bc7bd58 ("clk: meson: clk-pll: add enable bit") the
sys_pll can be disabled. However, since the CPU clock is derived from
sys_pll we don't want sys_pll to get disabled. The common clock
framework takes care of that for us by enabling all parent clocks of our
CPU clock when we mark the CPU clock with CLK_IS_CRITICAL.
Until now this is not a problem yet because all clocks in the CPU
clock's tree (including sys_pll) are read-only. However, once we allow
modifications to the clocks in that tree we will need this.
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/20181115224048.13511-4-martin.blumenstingl@googlemail.com
|
|
The cpu_div3 clock (cpu_in divided by 3) generates a signal with a duty
cycle of 33%. The CPU clock however requires a clock signal with a duty
cycle of 50% to run stable.
cpu_div3 was observed to be problematic when cycling through all
available CPU frequencies (with additional patches on top of this one)
while running "stress --cpu 4" in the background. This caused sporadic
hangs where the whole system would fully lock up.
Amlogic's 3.10 kernel code also does not use the cpu_div3 clock either
when changing the CPU clock.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181115224048.13511-3-martin.blumenstingl@googlemail.com
|
|
Since commit 6f888e7bc7bd58 ("clk: meson: clk-pll: add enable bit") our
PLLs also support the "enable" bit. Currently meson_clk_pll_enable
unconditionally resets the PLL, enables it, takes it out of reset and
waits until it is locked.
This works fine for our current clock trees. However, there will be a
problem once we allow modifications to sys_pll on Meson8, Meson8b and
Meson8m2 (which will be required for CPU frequency scaling):
the CPU clock is derived from the sys_pll clock. Once clk_enable is
called on the CPU clock this will be propagated by the common clock
framework up until the sys_pll clock. If we reset the PLL
unconditionally in meson_clk_pll_enable the CPU will be stopped (on
Meson8, Meson8b and Meson8m2).
To prevent this we simply check if the PLL is already enabled and do
reset the PLL if it's already enabled and locked.
Now that we have a utility function to check whether the PLL is enabled
we can also pass that to our clk_ops to let the common clock framework
know about the status of the hardware clock.
For now this is of limited use since the only common clock framework's
internal "disabled unused clocks" mechanism checks for this. Everything
else still uses the ref-counting (internal to the common clock
framework) when clk_enable is called.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181115224048.13511-2-martin.blumenstingl@googlemail.com
|
|
According to the public S805 datasheet HHI_SYS_CPU_CLK_CNTL1[29:20] is
the register for the CPU scale_div clock. This matches the code in
Amlogic's 3.10 GPL kernel sources:
N = (aml_read_reg32(P_HHI_SYS_CPU_CLK_CNTL1) >> 20) & 0x3FF;
This means that the divider register is 10 bit wide instead of 9 bits.
So far this is not a problem since all u-boot versions I have seen are
not using the cpu_scale_div clock at all (instead they are configuring
the CPU clock to run off cpu_in_sel directly).
The fixes tag points to the latest rework of the CPU clocks. However,
even before the rework it was wrong. Commit 7a29a869434e8b ("clk: meson:
Add support for Meson clock controller") defines MESON_N_WIDTH as 9 (in
drivers/clk/meson/clk-cpu.c). But since the old clk-cpu implementation
this only carries the fixes tag for the CPU clock rewordk.
Fixes: 251b6fd38bcb9c ("clk: meson: rework meson8b cpu clock")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20180927085921.24627-3-martin.blumenstingl@googlemail.com
|
|
The public S805 datasheet only mentions that
HHI_SYS_CPU_CLK_CNTL1[20:29] contains a divider called "cpu_scale_div".
Unfortunately it does not mention how to use the register contents.
The Amlogic 3.10 GPL kernel sources are using the following code to
calculate the CPU clock based on that register (taken from
arch/arm/mach-meson8/clock.c in the 3.10 Amlogic kernel, shortened to
make it easier to read):
N = (aml_read_reg32(P_HHI_SYS_CPU_CLK_CNTL1) >> 20) & 0x3FF;
if (sel == 3) /* use cpu_scale_div */
div = 2 * N;
else
div = ... /* not relevant for this example */
cpu_clk = parent_clk / div;
This suggests that the formula is: parent_rate / 2 * register_value
However, running perf (which can measure the CPU clock rate thanks to
the ARM PMU) shows that this formula is not correct.
This can be reproduced with the following steps:
1. boot into u-boot
2. let the CPU clock run off the XTAL clock:
mw.l 0xC110419C 0x30 1
3. set the cpu_scale_div register:
to value 0x1: mw.l 0xC110415C 0x801016A2 1
to value 0x2: mw.l 0xC110415C 0x802016A2 1
to value 0x5: mw.l 0xC110415C 0x805016A2 1
4. let the CPU clock run off cpu_scale_div:
mw.l 0xC110419C 0xbd 1
5. boot Linux
6. run: perf stat -aB stress --cpu 4 --timeout 10
7. check the "cycles" value
I get the following results depending on the cpu_scale_div value:
- (cpu_in_sel - this is the input clock for cpu_scale_div - runs at
1.2GHz)
- 0x1 = 300MHz
- 0x2 = 200MHz
- 0x5 = 100MHz
This means that the actual formula to calculate the output of the
cpu_scale_div clock is: parent_rate / 2 * (register value + 1).
The register value 0x0 is reserved. When letting the CPU clock run off
the cpu_scale_div while the value is 0x0 the whole board hangs (even in
u-boot).
I also verified this with the TWD timer: when adding this to the .dts
without specifying it's clock it will auto-detect the PERIPH (which is
the input clock of the TWD) clock rate (and the result is shown in the
kernel log). On Meson8, Meson8b and Meson8m2 the PERIPH clock is CPUCLK
divided by 4. This also matched for all three test-cases from above (in
all cases the TWD timer clock rate was approx. one fourth of the CPU
clock rate).
A small note regarding the "fixes" tag: the original issue seems to
exist virtually since forever. Even commit 28b9fcd016126e ("clk:
meson8b: Add support for Meson8b clocks") seems to handle this wrong. I
still decided to use commit 251b6fd38bcb9c ("clk: meson: rework meson8b
cpu clock") because this is the first commit which gets the CPU hiearchy
correct and thus it's the first commit where the cpu_scale_div register
is used correctly (apart from the bug in the cpu_scale_table).
Fixes: 251b6fd38bcb9c ("clk: meson: rework meson8b cpu clock")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20180927085921.24627-2-martin.blumenstingl@googlemail.com
|
|
The clock controller is located in a register range (called "HHI") which
contains more than just registers for the clock controller. Known
consumers of the HHI register range are:
- the clock controller
- a reset controller
- temperature sensor calibration coefficient (TSC) (only on Meson8b and
Meson8m2)
- HDMI controller
The main reason for using a syscon is the "temperature sensor
calibration coefficient" which has to be set for the built-in temperature
sensor to work correctly. Four TSC bits are located in the SAR ADC's
register space. However on Meson8b and Meson8m2 there is a fifth TSC bit
which is unfortunately located in the HHI register space. To be more
precise, bit 9 of the HHI_DPLL_TOP_0 register (which sits right between
the HHI_SYS_PLL and HHI_VID_PLL registers).
Get the regmap from the parent (HHI syscon) node to support all
functionality of the HHI register range. Backwards compatibility with
old .dtbs is ensured by falling back to parsing the registers just like
before this change.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181028120859.5735-3-martin.blumenstingl@googlemail.com
|
|
Add the clocks entries used in the video clock path, the clock path
is doubled to permit having different synchronized clocks for different
parts of the video pipeline.
All dividers are flagged with CLK_GET_RATE_NOCACHE, and all gates are flagged
with CLK_IGNORE_UNUSED since they are currently directly handled by the
Meson DRM Driver.
Once the DRM Driver is fully migrated to using the Common Clock Framework
to handle the video clock tree, the CLK_GET_RATE_NOCACHE and CLK_IGNORE_UNUSED
will be dropped.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Link: http://lkml.kernel.org/r/1541516257-16157-5-git-send-email-narmstrong@baylibre.com
|
|
Add the video clock bindings covering all the video graphics pipeline
and the HDMI controller.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Link: http://lkml.kernel.org/r/1541516257-16157-4-git-send-email-narmstrong@baylibre.com
|
|
In an attempt to better describe the HDMI PLL, a single DCO clock was
left for GXBB and GXL, but the GXL DCO does not have a pre-multiplier.
This patch adds back a GXL specific HDMI PLL DCO with xtal as parent.
Fixes: 87173557d2f6 ("clk: meson: clk-pll: remove od parameters")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Link: http://lkml.kernel.org/r/1541516257-16157-3-git-send-email-narmstrong@baylibre.com
|
|
Add support the VID_PLL fully programmable divider used right after the
HDMI PLL clock source. It is used to achieve complex fractional division
with a programmble bitfield.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Link: http://lkml.kernel.org/r/1541516257-16157-2-git-send-email-narmstrong@baylibre.com
|
|
Certain firmware configurations "protect" clks and cause the entire
system to reboot when a non-secure OS such as Linux tries to read or
write protected clk registers. But other firmware configurations allow
reading or writing the same registers, and they may actually require
that the OS use the otherwise locked down clks. Support the
'protected-clocks' property by never registering these protected clks
with the common clk framework. This way, when firmware is protecting
these clks we won't have the chance to ever read or write these
registers and take down the entire system.
Cc: Taniya Das <tdas@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
