You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
kernel_samsung_sm7125/Documentation/devicetree/bindings/pwm/pwm-qti-lpg.txt

253 lines
8.0 KiB

Qualcomm Technologies, Inc. LPG driver specific bindings
This binding document describes the properties of LPG (Light Pulse Generator)
device module in Qualcomm Technologies, Inc. PMIC chips.
- compatible:
Usage: required
Value type: <string>
Definition: Must be "qcom,pwm-lpg".
- reg:
Usage: required
Value type: <prop-encoded-array>
Definition: Register base for LPG and LUT modules.
- reg-names:
Usage: required
Value type: <string>
Definition: The name of the register defined in the reg property.
It must have "lpg-base", "lut-base" is optional but
it's required if any LPG channels support LUT mode
with a LUT module.
- #pwm-cells:
Usage: required
Value type: <u32>
Definition: The number of cells in "pwms" property specified in
PWM user nodes. It should be 2. The first cell is
the PWM channel ID indexed from 0, and the second
cell is the PWM default period in nanoseconds.
- qcom,num-lpg-channels:
Usage: required
Value type: <u32>
Definition: The number of the consecutive LPG/PWM channels in the chip.
- nvmem-names:
Usage: optional
Value type: <string>
Definition: The nvmem device name for the SDAM module where the LUT
pattern is stored. It must be "ppg_sdam". This property
is required only when LUT mode is supported with a SDAM
module instead of a LUT module.
- nvmem:
Usage: optional
Value type: <phandle>
Definition: Phandle of the nvmem device to access the LUT stored
in the SDAM module. This property is required only when
LUT mode is supported and the LUT pattern is stored in a
SDAM module instead of a LUT module.
- qcom,pbs-client
Usage: optional
Value type: <phandle>
Definition: Phandle of the PBS client used for sending the PBS
trigger. This property is required when LUT mode is
supported and the LUT pattern is stored in a SDAM
module instead of a LUT module.
- qcom,lut-sdam-base:
Usage: optional
Value type: <u32>
Definition: The register base of the LUT entries stored in SDAM. This
property is required only when LUT mode is supported and
the LUT pattern is stored in a SDAM module instead of a
LUT module.
- qcom,lut-patterns:
Usage: optional
Value type: <prop-encoded-array>
Definition: Duty ratios in percentages for LPG working at LUT mode.
These duty ratios will be translated into PWM values
and stored in LUT or SDAM module shared for all LPG
channels. The LUT module has resource to store 47 PWM
values at max while SDAM module can store upto 64 PWM
values. This property is required if any LPG channels
support LUT mode.
- qcom,sync-channel-ids:
Usage: optional
Value type: <prop-encoded-array>
Definition: The hardware IDs of the LPG channel that required be
grouped together. These channels will share the same LUT
ramping configuration so that they will be enabled with a
synchronized pattern. If the LUT ramping configuration
differs for the channels grouped for synchronization,
configuration of the first channel will be applied for
all others.
Subnode is optional if LUT mode is not required, it's required if any LPG
channels expected to be supported in LUT mode.
Subnode properties:
Subnodes for each LPG channel (lpg@X) can be defined if any of the following
parameters needs to be configured for that channel.
- qcom,lpg-chan-id:
Usage: required
Value type: <u32>
Definition: The LPG channel's hardware ID indexed from 1. Allowed
range is 1 - 8. Maximum value depends on the number of
channels supported on PMIC.
- qcom,lpg-sdam-base:
Usage: optional
Value type: <u32>
Definition: Register base address for LPG configuration in SDAM for
the LPG channel specified under "qcom,lpg-chan-id".
This property is required if LUT mode is supported with
a SDAM module.
- qcom,ramp-step-ms:
Usage: required
Value type: <u32>
Definition: The step duration in milliseconds for LPG staying at each
duty specified in the LUT pattern. Allowed range:
1 - 511 when LUT module is used, and 8 - 2000 when SDAM
is used.
- qcom,ramp-high-index:
Usage: required
Value type: <u32>
Definition: The high index of the LUT pattern where LPG ends up
ramping to. Allowed range: 1 - 47 when LUT module
is used, and 1 - 64 when SDAM module is used.
- qcom,ramp-low-index:
Usage: required
Value type: <u32>
Definition: The low index of the LUT pattern from where LPG begins
ramping from. The ramp-low-index should be always less
than ramp-high-index when SDAM module is used. Allowed
range: 0 - 46 when LUT module is used, and 0 - 63 when
SDAM module is used.
- qcom,ramp-pattern-repeat:
Usage: optional
Value type: <empty>
Definition: The flag to specify if LPG would be ramping with the LUT
pattern repeatedly.
- qcom,ramp-from-low-to-high:
Usage: optional
Value type: <empty>
Definition: The flag to specify the LPG ramping direction. The ramping
direction is from low index to high index of the LUT
pattern if it's specified. This property is not required
when SDAM module is used.
- qcom,ramp-toggle:
Usage: optional
Value type: <empty>
Definition: The flag to specify if LPG would toggle the LUT pattern
in ramping. If toggling enabled, LPG would return to the
low index when high index is reached, or return to the high
index when low index is reached. This property is not
required when SDAM module is used.
- qcom,ramp-pause-hi-count:
Usage: optional
Value type: <u32>
Definition: The step count that LPG stop the output when it ramped up
to the high index of the LUT. This property is not
required when SDAM module is used.
- qcom,ramp-pause-lo-count:
Usage: optional
Value type: <u32>
Definition: The step count that LPG stop the output when it ramped up
to the low index of the LUT. This property is not
required when SDAM module is used.
Example when LUT pattern is stored in a LUT module:
pm8150l_lpg: lpg@b100 {
compatible = "qcom,pwm-lpg";
reg = <0xb100 0x600>, <0xb000 0x100>;
reg-names = "lpg-base", "lut-base";
qcom,num-lpg-channels = <6>;
#pwm-cells = <2>;
qcom,lut-patterns = <0 14 28 42 56 70 84 100
100 84 70 56 42 28 14 0>;
lpg@1 {
qcom,lpg-chan-id = <1>;
qcom,ramp-step-ms = <200>;
qcom,ramp-pause-hi-count = <10>;
qcom,ramp-pause-lo-count = <10>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-from-low-to-high;
qcom,ramp-pattern-repeat;
};
lpg@2 {
qcom,lpg-chan-id = <2>;
qcom,ramp-step-ms = <200>;
qcom,ramp-pause-hi-count = <10>;
qcom,ramp-pause-lo-count = <10>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-from-low-to-high;
qcom,ramp-pattern-repeat;
};
lpg@3 {
qcom,lpg-chan-id = <3>;
qcom,ramp-step-ms = <200>;
qcom,ramp-pause-hi-count = <10>;
qcom,ramp-pause-lo-count = <10>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-from-low-to-high;
qcom,ramp-pattern-repeat;
};
};
Example when LUT pattern is stored in a SDAM module:
pmi632_lpg: lpg@b100 {
compatible = "qcom,pwm-lpg";
reg = <0xb100 0x600>;
reg-names = "lpg-base";
#pwm-cells = <2>;
nvmem-names = "ppg_sdam";
nvmem = <&sdam7>;
qcom,pbs-client = <&pbs_client_3>;
qcom,lut-sdam-base = <0x80>;
qcom,lut-patterns = <0 14 28 42 56 70 84 100
100 84 70 56 42 28 14 0>;
lpg@1 {
qcom,lpg-chan-id = <1>;
qcom,ramp-step-ms = <200>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-pattern-repeat;
qcom,lpg-sdam-base = <0x48>:
};
lpg@2 {
qcom,lpg-chan-id = <2>;
qcom,ramp-step-ms = <200>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-pattern-repeat;
qcom,lpg-sdam-base = <0x56>;
};
lpg@3 {
qcom,lpg-chan-id = <3>;
qcom,ramp-step-ms = <200>;
qcom,ramp-low-index = <0>;
qcom,ramp-high-index = <15>;
qcom,ramp-pattern-repeat;
qcom,lpg-sdam-base = <0x64>;
};
};