A future patch will implement a clock uclass driver for Tegra. That driver
will call into Tegra's existing clock code to simplify the transition;
this avoids tieing the clock uclass patches into significant refactoring
of the existing custom clock API implementation.
Some of the Tegra clock APIs that manipulate peripheral clocks require
both the peripheral clock ID and parent clock ID to be passed in together.
However, the clock uclass API does not require any such "parent"
parameter, so the clock driver must determine this information itself.
This patch implements new Tegra- specific clock API
clock_get_periph_parent() for this purpose.
The new API is implemented in the core Tegra clock code rather than SoC-
specific clock code. The implementation uses various SoC-/clock-specific
data. That data is only available in SoC-specific clock code.
Consequently, two new internal APIs are added that enable the core clock
code to retrieve this information from the SoC-specific clock code. Due to
the structure of the Tegra clock code, this leads to some unfortunate code
duplication. However, this situation predates this patch.
Ideally, future work will de-duplicate the Tegra clock code, and migrate
it into drivers/clk/tegra. However, such refactoring is kept separate from
this series.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Currently, Tegra peripheral drivers control two aspects of their HW module
clock(s):
1) The clock enable/rate for the peripheral clock itself.
2) The system-level clock tree setup, i.e. the clock parent.
Aspect 1 is reasonable, but aspect 2 is a system-level decision, not
something that an individual peripheral driver should in general know
about or influence. Such system-level knowledge ties the driver to a
specific SoC implementation, even when they use generic APIs for clock
manipulation, since they must have SoC-specific knowledge such as parent
clock IDs. Limited exceptions exist, such as where peripheral HW is
expected to dynamically switch between clock sources at run-time, such
as CPU clock scaling or display clock conflict management in a multi-head
scenario.
This patch enhances the Tegra core code to perform system-level clock
tree setup, in a similar fashion to the Linux kernel Tegra clock driver.
This will allow future patches to simplify peripheral drivers by removing
the clock parent setup logic.
This change is required prior to converting peripheral drivers to use the
standard clock APIs, since:
1) The clock uclass doesn't currently support a set_parent() operation.
Adding one is possible, but not necessary at the moment.
2) The clock APIs retrieve all clock IDs from device tree, and the DT
bindings for almost all peripherals only includes information about the
relevant peripheral clocks, and not any potential parent clocks.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This bit needs to be set for system suspend/resume to work. This setting
will be documented in an updated TRM at some time in the future.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Implement the procedure that the TRM mandates to initialize PLLREFE and
PLLE. This makes the PLL actually lock.
Note that this section of the TRM is being cleaned up to remove some
confusion. The set of register accesses in this patch should be final,
although the step numbers/descriptions might still change.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
While clk_m and the oscillator run at the same frequencies on Tegra114
and Tegra124, clk_m is the proper source for the architected timer. On
more recent Tegra generations, Tegra210 and later, both the oscillator
and clk_m can run at different frequencies. clk_m will be divided down
from the oscillator.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
On currently supported SoCs, clk_m always runs at the same frequency as
the oscillator input. However newer SoC generations such as Tegra210 no
longer have that restriction. Prepare for that by separating clk_m from
the oscillator clock and allow SoC code to override the clk_m rate.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
The logic for simple PLLs on T124 was broken by this commit:
722e000c Tegra: PLL: use per-SoC pllinfo table instead of PLL_DIVM/N/P, etc.
Correct it by reading from the same pll_misc register that it writes to and
adding an entry for the DP PLL in the pllinfo table.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Added PLL variables (dividers mask/shift, lock enable/detect, etc.)
to new pllinfo struct for each Soc/PLL. PLLA/C/D/E/M/P/U/X.
Used pllinfo struct in all clock functions, validated on T210.
Should be equivalent to prior code on T124/114/30/20. Thanks
to Marcel Ziswiler for corrections to the T20/T30 values.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Added 38.4MHz/48MHz entries to pll_x_table for CPU PLL. Needs
to be measured - should be close to 700MHz (1.4G/2).
Note that some freqs aren't in the PLLU table in T210 TRM
(13, 26MHz), so I used the 12MHz table entry for them. They
shouldn't be selected since they're not viable T210 OSC freqs.
Since there are now 2 new OSC defines, all tables (pll_x_table,
PLLU) had to increase by two entries, but since 38.4/48MHz are
not viable osc freqs on T20/30/114, etc, they're just set to 0.
Signed-off-by: Tom Warren <twarren@nvidia.com>
All based off of Tegra124. As a Tegra210 board is brought
up, these may change a bit to match the HW more closely,
but probably 90% of this is identical to T124.
Note that since T210 is a 64-bit build, it has no SPL
component, and hence no cpu.c for Tegra210.
Signed-off-by: Tom Warren <twarren@nvidia.com>
