Re: [PATCH v3 01/11] of: Add bindings of hw throttle for Tegra soctherm

Rob Herring
2016-05-04T13:35:27Z

On Tue, May 03, 2016 at 06:13:20PM +0800, Wei Ni wrote:
> Add HW throttle configuration sub-node for soctherm, which
> is used to describe the throttle event, and worked as a
> cooling device. The "hot" type trip in thermal zone can
> be bound to this cooling device, and trigger the throttle
> function.
>
> Signed-off-by: Wei Ni <wni@nvidia.com>
> ---
> .../bindings/thermal/nvidia,tegra124-soctherm.txt | 120 ++++++++++++++++++++-
> 1 file changed, 118 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> index edebfa0a985e..6ba8ae3f59ed 100644
> --- a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> +++ b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> @@ -10,8 +10,14 @@ Required properties :
> - compatible : For Tegra124, must contain "nvidia,tegra124-soctherm".
> For Tegra132, must contain "nvidia,tegra132-soctherm".
> For Tegra210, must contain "nvidia,tegra210-soctherm".
> -- reg : Should contain 1 entry:
> +- reg : Should contain at least 2 entries for each entry in reg-names:
> - SOCTHERM register set
> + - Tegra CAR register set: Required for Tegra124 and Tegra210.
> + - CCROC register set: Required for Tegra132.
> +- reg-names : Should contain at least 2 entries:
> + - soctherm-reg
> + - car-reg
> + - ccroc-reg
> - interrupts : Defines the interrupt used by SOCTHERM
> - clocks : Must contain an entry for each entry in clock-names.
> See ../clocks/clock-bindings.txt for details.
> @@ -25,17 +31,44 @@ Required properties :
> - #thermal-sensor-cells : Should be 1. See ./thermal.txt for a description
> of this property. See <dt-bindings/thermal/tegra124-soctherm.h> for a
> list of valid values when referring to thermal sensors.
> +- nvidia,throttle-cfgs: A sub-node which is a container of configuration for
> + each hardware throttle events. These events can be set as cooling devices.
> + * throttle events: Sub-nodes must be named as "nvidia,light" or "nvidia,heavy".
> + Properties:
> + - nvidia,priority: Each throttles has its own throttle settings, so the
> + SW need to set priorities for various throttle, the HW arbiter can select
> + the final throttle settings.
> + Bigger value indicates higher priority, In general, higher priority
> + translates to lower target frequency. SW needs to ensure that critical
> + thermal alarms are given higher priority, and ensure that there is
> + no race if priority of two vectors is set to the same value.

What are valid range of values?

> + - nvidia,cpu-throt-depth: This property is for Tegra124 and Tegra210.
> + It is the throttling depth of pulse skippers, it's the percentage
> + throttling.

Add unit suffix (-percent)

> + - nvidia,cpu-throt-level: This property is only for Tegra132, it is the
> + level of pulse skippers, which used to throttle clock frequencies. It
> + indicates cpu clock throttling depth, and the depth can be programmed.
> + Must set as following values:
> + TEGRA_SOCTHERM_THROT_LEVEL_LOW, TEGRA_SOCTHERM_THROT_LEVEL_MED
> + TEGRA_SOCTHERM_THROT_LEVEL_HIGH, TEGRA_SOCTHERM_THROT_LEVEL_NONE
> + - #cooling-cells: Should be 1. This cooling device only support on/off state.
> + See ./thermal.txt for a description of this property.
>
> Note:
> - the "critical" type trip points will be set to SOC_THERM hardware as the
> shut down temperature. Once the temperature of this thermal zone is higher
> than it, the system will be shutdown or reset by hardware.
> +- the "hot" type trip points will be set to SOC_THERM hardware as the throttle
> +temperature. Once the the temperature of this thermal zone is higher
> +than it, it will trigger the HW throttle event.
>
> Example :
>
> soctherm@700e2000 {
> compatible = "nvidia,tegra124-soctherm";
> - reg = <0x0 0x700e2000 0x0 0x1000>;
> + reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */
> + 0x0 0x60006000 0x0 0x400 /* CAR reg_base */
> + reg-names = "soctherm-reg", "car-reg";
> interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
> clocks = <&tegra_car TEGRA124_CLK_TSENSOR>,
> <&tegra_car TEGRA124_CLK_SOC_THERM>;
> @@ -44,6 +77,76 @@ Example :
> reset-names = "soctherm";
>
> #thermal-sensor-cells = <1>;
> +
> + nvidia,throttle-cfgs {

Drop the vendor prefix in node names.

> + /*
> + * When the "heavy" cooling device triggered,
> + * the HW will skip cpu clock's pulse in 85% depth
> + */
> + throttle_heavy: nvidia,heavy {
> + nvidia,priority = <100>;
> + nvidia,cpu-throt-depth = <85>;
> +
> + #cooling-cells = <1>;
> + };
> +
> + /*
> + * When the "light" cooling device triggered,
> + * the HW will skip cpu clock's pulse in 50% depth
> + */
> + throttle_light: nvidia,light {
> + nvidia,priority = <80>;
> + nvidia,cpu-throt-depth = <50>;
> +
> + #cooling-cells = <1>;
> + };
> +
> + /*
> + * If these two devices are triggered in same time, the HW throttle
> + * arbiter will select the highest priority as the final throttle
> + * settings to skip cpu pulse.
> + */
> + };
> + };
> +
> +Example: referring to Tegra132's "reg", "reg-names" and "throttle-cfgs" :
> +
> + soctherm@0,700e2000 {

Drop the comma in the unit address.

> + compatible = "nvidia,tegra132-soctherm";
> + reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */
> + 0x0 0x70040000 0x0 0x200>; /* CCROC reg_base */;
> + reg-names = "soctherm-reg", "ccroc-reg";
> +
> + nvidia,throttle-cfgs {
> + /*
> + * When the "heavy" cooling device triggered,
> + * the HW will skip cpu clock's pulse in HIGH level
> + */
> + throttle_heavy: nvidia,heavy {
> + nvidia,priority = <100>;
> + nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_HIGH>;
> +
> + #cooling-cells = <1>;
> + };
> +
> + /*
> + * When the "light" cooling device triggered,
> + * the HW will skip cpu clock's pulse in MED level
> + */
> + throttle_light: nvidia,light {
> + nvidia,priority = <80>;
> + nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_MED>;
> +
> + #cooling-cells = <1>;
> + };
> +
> + /*
> + * If these two devices are triggered in same time, the HW throttle
> + * arbiter will select the highest priority as the final throttle
> + * settings to skip cpu pulse.
> + */
> +
> + };
> };
>
> Example: referring to thermal sensors :
> @@ -62,6 +165,19 @@ Example: referring to thermal sensors :
> hysteresis = <1000>;
> type = "critical";
> };
> +
> + cpu_throttle_trip: throttle-trip {
> + temperature = <100000>;
> + hysteresis = <1000>;
> + type = "hot";
> + };
> + };
> +
> + cooling-maps {
> + map0 {
> + trip = <&cpu_throttle_trip>;
> + cooling-device = <&throttle_heavy 1 1>;
> + };
> };
> };
> };
> --
> 1.9.1
>