Pass the clock controller udevice into clk_register_composite(),
so it can be passed further to any registered composite clocks
and used for look up of parent clock referenced in DT "clocks"
and "clock-names" properties by phandle and name pair.
Use the clock controller udevice in imx8m_clk_mux_set_parent()
to perform accurate look up of parent clock referenced in the
CCM driver by name. If the clock name that is being looked up
matches one of the names listed in the clock controller DT node
"clock-names" array property, then the offset of the name is
looked up in the "clocks" DT property and the phandle at that
offset is resolved to the parent clock udevice. The test to
determine whether a particular driver instance registered with
clock uclass matches the parent clock is done by comparing the
OF nodes of the clock registered with clock uclass and parent
clock resolved from the phandle.
Example:
drivers/clk/imx/clk-imx8mm.c:
static const char * const imx8mm_a53_sels[] = {"osc_24m", "arm_pll_out", ...
_____________|
arch/arm/dts/imx8mm.dtsi: |
clk: clock-controller@30380000 { v
clock-names = "osc_32k", "osc_24m", ...
|
v
clocks = <&osc_32k>, <&osc_24m>, ...
}; _______________________|
... |
/ { v
osc_24m: clock-osc-24m {
compatible = "fixed-clock";
...
};
Signed-off-by: Marek Vasut <marex@denx.de>
Reported-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Tested-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Adam Ford <aford173@gmail.com> # imx8mp-beacon
Pass struct udevice * into imx_clk_composite*() functions, so the
clock core would have access to parent struct udevice *.
Signed-off-by: Marek Vasut <marex@denx.de>
Upstream Linux commit f90b68d6c8b0.
The CORE/BUS root slice has following design, simplied graph:
The difference is core not have pre_div block.
A composite core/bus clk has 8 inputs for mux to select, saying clk[0-7].
It support target(smart) interface and normal interface. Target interface
is exported for programmer easy to configure ccm root. Normal interface
is also exported, but we not use it in our driver, because it will
introduce more complexity compared with target interface.
The normal interface simplified as below:
SEL_A GA
+--+ +-+
| +->+ +------+
CLK[0-7]--->+ | +-+ |
| | | +----v---+ +----+
| +--+ |pre_diva+----> | +---------+
| +--------+ |mux +--+post_div |
| +--+ |pre_divb+--->+ | +---------+
| | | +----^---+ +----+
+--->+ | +-+ |
| +->+ +------+
+--+ +-+
SEL_B GB
The mux in the upper pic is not the target interface MUX, target
interface MUX is hiding SEL_A and SEL_B. When you choose clk[0-7],
you are actually writing SEL_A or SEL_B depends on the internal
counter which will also control the internal "mux".
The target interface simplified as below which is used by Linux Kernel:
CLK[0-7]--->MUX-->Gate-->pre_div-->post_div
A requirement of the Target Interface's software is that the
target clock source is active, it means when setting SEL_A, the
current input clk to SEL_A must be active, same to SEL_B.
We touch target interface, but hardware logic actually also need
configure normal interface.
There will be system hang, when doing the following steps:
The initial state:
SEL_A/SEL_B are both sourcing from clk0, the internal counter
choose SEL_A.
1. switch mux from clk0 to clk1
The hardware logic will choose SEL_B and configure SEL_B to clk1.
SEL_A no changed.
2. gate off clk0
Disable clk0, then the input to SEL_A is off.
3. switch from clk1 to clk2
The hardware logic will choose SEL_A and configure SEL_A to clk2,
however the current SEL_A input clk0 is off, the system hang.
The solution to fix the issue is in step 1, write twice to
target interface MUX, it will make SEL_A/SEL_B both sources
from clk1, then no need to care about the state of clk0. And
finally system performs well.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
The mux flags (u8), div flags (u8), and gate flags (u8) are not the clk
flags (unsigned long). They have different meanings
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
As part of bringing the master branch back in to next, we need to allow
for all of these changes to exist here.
Reported-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Tom Rini <trini@konsulko.com>
When bringing in the series 'arm: dts: am62-beagleplay: Fix Beagleplay
Ethernet"' I failed to notice that b4 noticed it was based on next and
so took that as the base commit and merged that part of next to master.
This reverts commit c8ffd1356d, reversing
changes made to 2ee6f3a5f7.
Reported-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Tom Rini <trini@konsulko.com>
At present devres.h is included in all files that include dm.h but few
make use of it. Also this pulls in linux/compat which adds several more
headers. Drop the automatic inclusion and require files to include devres
themselves. This provides a good indication of which files use devres.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
