NVIDIA Tegra Power Management Controller (PMC)
== Power Management Controller Node ==
The PMC block interacts with an external Power Management Unit. The PMC
mostly controls the entry and exit of the system from different sleep
modes. It provides power-gating controllers for SoC and CPU power-islands.
Required properties:
- name : Should be pmc
- compatible : Should contain one of the following:
For Tegra20 must contain “nvidia,tegra20-pmc”.
For Tegra30 must contain “nvidia,tegra30-pmc”.
For Tegra114 must contain “nvidia,tegra114-pmc”
For Tegra124 must contain “nvidia,tegra124-pmc”
For Tegra132 must contain “nvidia,tegra124-pmc”
For Tegra210 must contain “nvidia,tegra210-pmc” - reg : Offset and length of the register set for the device
- clocks : Must contain an entry for each entry in clock-names.
See ../clocks/clock-bindings.txt for details. - clock-names : Must include the following entries:
“pclk” (The Tegra clock of that name),
“clk32k_in” (The 32KHz clock input to Tegra).
Optional properties:
- nvidia,invert-interrupt : If present, inverts the PMU interrupt signal.
The PMU is an external Power Management Unit, whose interrupt output
signal is fed into the PMC. This signal is optionally inverted, and then
fed into the ARM GIC. The PMC is not involved in the detection or
handling of this interrupt signal, merely its inversion. - nvidia,suspend-mode : The suspend mode that the platform should use.
Valid values are 0, 1 and 2:
0 (LP0): CPU + Core voltage off and DRAM in self-refresh
1 (LP1): CPU voltage off and DRAM in self-refresh
2 (LP2): CPU voltage off - nvidia,core-power-req-active-high : Boolean, core power request active-high
- nvidia,sys-clock-req-active-high : Boolean, system clock request active-high
- nvidia,combined-power-req : Boolean, combined power request for CPU & Core
- nvidia,cpu-pwr-good-en : Boolean, CPU power good signal (from PMIC to PMC)
is enabled.
Required properties when nvidia,suspend-mode is specified:
- nvidia,cpu-pwr-good-time : CPU power good time in uS.
- nvidia,cpu-pwr-off-time : CPU power off time in uS.
- nvidia,core-pwr-good-time :
Core power good time in uS. - nvidia,core-pwr-off-time : Core power off time in uS.
Required properties when nvidia,suspend-mode=<0>:
- nvidia,lp0-vec :
Starting address and length of LP0 vector
The LP0 vector contains the warm boot code that is executed by AVP when
resuming from the LP0 state. The AVP (Audio-Video Processor) is an ARM7
processor and always being the first boot processor when chip is power on
or resume from deep sleep mode. When the system is resumed from the deep
sleep mode, the warm boot code will restore some PLLs, clocks and then
bring up CPU0 for resuming the system.
Hardware-triggered thermal reset:
On Tegra30, Tegra114 and Tegra124, if the ‘i2c-thermtrip’ subnode exists,
hardware-triggered thermal reset will be enabled.
Required properties for hardware-triggered thermal reset (inside ‘i2c-thermtrip’):
- nvidia,i2c-controller-id : ID of I2C controller to send poweroff command to. Valid values are
described in section 9.2.148 "APBDEV_PMC_SCRATCH53_0" of the Tegra K1 Technical Reference Manual. - nvidia,bus-addr : Bus address of the PMU on the I2C bus
- nvidia,reg-addr : I2C register address to write poweroff command to
- nvidia,reg-data : Poweroff command to write to PMU
Optional properties for hardware-triggered thermal reset (inside ‘i2c-thermtrip’):
- nvidia,pinmux-id : Pinmux used by the hardware when issuing poweroff command.
Defaults to 0. Valid values are described in section 12.5.2 "Pinmux Support" of the Tegra4 Technical Reference Manual.
Optional nodes:
- powergates : This node contains a hierarchy of power domain nodes, which
should match the powergates on the Tegra SoC. See "Powergate Nodes" below.
Example:
/ SoC dts including file
pmc@7000f400 {
compatible = “nvidia,tegra20-pmc”;
reg = <0x7000e400 0x400>;
clocks = <&tegra_car 110>, <&clk32k_in>;
clock-names = “pclk”, “clk32k_in”;
nvidia,invert-interrupt;
nvidia,suspend-mode = <1>;
nvidia,cpu-pwr-good-time = <2000>;
nvidia,cpu-pwr-off-time = <100>;
nvidia,core-pwr-good-time = <3845 3845>;
nvidia,core-pwr-off-time = <458>;
nvidia,core-power-req-active-high;
nvidia,sys-clock-req-active-high;
nvidia,lp0-vec = <0xbdffd000 0x2000>;
};
/ Tegra board dts file
{
…
pmc@7000f400 {
i2c-thermtrip {
nvidia,i2c-controller-id = <4>;
nvidia,bus-addr = <0x40>;
nvidia,reg-addr = <0x36>;
nvidia,reg-data = <0x2>;
};
};
…
clocks {
compatible = “simple-bus”;
#address-cells = <1>;
#size-cells = <0>;
clk32k_in: clock {
compatible = "fixed-clock";
reg=<0>;
#clock-cells = <0>;
clock-frequency = <32768>;
};
};
...
};
== Powergate Nodes ==
Each of the powergate nodes represents a power-domain on the Tegra SoC
that can be power-gated by the Tegra PMC. The name of the powergate node
should be one of the below. Note that not every powergate is applicable
to all Tegra devices and the following list shows which powergates are
applicable to which devices. Please refer to the Tegra TRM for more
details on the various powergates.
Name Description Devices Applicable
3d 3D Graphics Tegra20/114/124/210
3d0 3D Graphics 0 Tegra30
3d1 3D Graphics 1 Tegra30
aud Audio Tegra210
dfd Debug Tegra210
dis Display A Tegra114/124/210
disb Display B Tegra114/124/210
heg 2D Graphics Tegra30/114/124/210
iram Internal RAM Tegra124/210
mpe MPEG Encode All
nvdec NVIDIA Video Decode Engine Tegra210
nvjpg NVIDIA JPEG Engine Tegra210
pcie PCIE Tegra20/30/124/210
sata SATA Tegra30/124/210
sor Display interfaces Tegra124/210
ve2 Video Encode Engine 2 Tegra210
venc Video Encode Engine All
vdec Video Decode Engine Tegra20/30/114/124
vic Video Imaging Compositor Tegra124/210
xusba USB Partition A Tegra114/124/210
xusbb USB Partition B Tegra114/124/210
xusbc USB Partition C Tegra114/124/210
Required properties:
- clocks: Must contain an entry for each clock required by the PMC for
controlling a power-gate. See ../clocks/clock-bindings.txt for details. - resets: Must contain an entry for each reset required by the PMC for
controlling a power-gate. See ../reset/reset.txt for details. - #power-domain-cells: Must be 0.
Example:
pmc: pmc@7000e400 {
compatible = "nvidia,tegra210-pmc";
reg = <0x0 0x7000e400 0x0 0x400>;
clocks = <&tegra_car TEGRA210_CLK_PCLK>, <&clk32k_in>;
clock-names = "pclk", "clk32k_in";
powergates {
pd_audio: aud {
clocks = <&tegra_car TEGRA210_CLK_APE>,
<&tegra_car TEGRA210_CLK_APB2APE>;
resets = <&tegra_car 198>;
#power-domain-cells = <0>;
};
};
};
== Powergate Clients ==
Hardware blocks belonging to a power domain should contain a “power-domains”
property that is a phandle pointing to the corresponding powergate node.
Example:
adma: adma@702e2000 {
...
power-domains = <&pd_audio>;
...
};
