QPNP Haptic

QPNP (Qualcomm Technologies Plug N Play) Haptic is a peripheral on
Qualcomm Technologies PMICs.  The PMIC is connected to Host processor
via SPMI bus.

This device can be operated in four modes - direct, buffer,
pwm(pulse width modulation) and audio.

Required Properties:
 - compatible: must be "qcom,qpnp-haptic"
 - reg: address of device
 - qcom,actuator-type: must be one of "erm" or "lra"
 - qcom,play-mode : must be one of "buffer", "direct", "pwm" or "audio"

Optional Properties:
 - qcom,timeout-ms: timeout in ms.
 - qcom,vmax-mv : maximum output voltage in milli volts
 - qcom,ilim-ma : maximum output current limit threshold in milli amps
 - qcom,int-pwm-freq-khz : frequency for internal pwm
 - qcom,en-brake : specify to enable internal reverse braking
 - qcom,brake-pattern : 4 byte active brake pattern. Each pattern represents
		2-bit amplitude control 0x00: 0, 0x01: vmax/4, 0x02: vmax/2,
		0x03: vmax. Default values are 0x00.
 - qcom,sc-deb-cycles : short circuit debounce in internal pwm switching clock cycles
 - qcom,use-play-irq : boolean, use this if the device uses irq for play
 - qcom,use-sc-irq : boolean, use this if the device uses irq for play
 - interrupts:	Specifies the interrupt associated with Haptics. The available
		interrupts are play and short circuit. The values for play and
		short circuit are <0x3 0xc0 0x0> and <0x3 0xc0 0x1>.
 - interrupt-names: Specify the interrupt names associated with interrupts. Must be
		    one of "play-irq" or "sc-irq"
 - vcc_pon-supply: power-on driver regulator

Optional properties for buffer play mode:
 - qcom,wave-samples : 8 byte buffer representing the wave. The bits in each sample
		are represented as follows- bit 0: reserved, bits 1 to 5: amplitude
		of the waveform, bit 6: over drive and bit 7: direction.
 - qcom,wave-shape : must be "sine" or "square"
 - qcom,wave-rep-cnt : repetition count for wave form
 - qcom,wave-samp-rep-cnt : repetition count for each sample of wave
 - qcom,wave-play-rate-us : duration at which each sample to be played in micro seconds

Required properties for pwm play mode:
 - qcom,pwm-channel: pwm channel the led will operate on
 - qcom,period-us: pwm period in us
 - qcom,duty-us: pwm duty cycle in us
 - qcom,ext-pwm-dtest-line: dtest line to used with pwm

Optional properties for pwm play mode:
 - qcom,ext-pwm-freq-khz : frequency for external pwm in kilo HZ

Optional properties when qcom,actuator-type is "lra"
 - qcom,correct-lra-drive-freq : boolean, use this to ensure LRA is driven at correct resonant
				 frequency, which may change due to operating conditions.
 - qcom,misc-trim-error-rc19p2-clk-reg-present : boolean, use this if TRIM_ERROR_RC19P2_CLK
				register is present in MISC module. This register holds
				the frequency error in 19.2Mhz RC clock.
 - qcom,lra-auto-res-mode : auto resonance technique, four different modes
			"none" : no auto resonance
			"zxd" : zero crossing based discontinuous method
			"qwd" : quarter wave drive method
			"max-qwd" : Maximum QWD
			"zxd-eop" : ZXD + End of pattern (This is the Default)
 - qcom,lra-high-z : High Z configuration for auto resonance. Possible string values are
			"none", "opt1", "opt2" and "opt3" (default)
 - qcom,lra-res-cal-period : Auto resonance calibration period. The values range from
			4 to 32(default)

Example:
		qcom,haptic@c000 {
			status = "disabled";
			compatible = "qcom,qpnp-haptic";
			reg = <0xc000 0x100>;
			interrupts = <0x3 0xc0 0x0>,
				     <0x3 0xc0 0x1>;
			interrupt-names = "sc-irq", "play-irq";
			vcc_pon-supply = <&pon_perph_reg>;
			qcom,play-mode = "direct";
			qcom,wave-play-rate-us = <5263>;
			qcom,actuator-type = "lra";
			qcom,wave-shape = "square";
			qcom,vmax-mv = <2000>;
			qcom,ilim-ma = <800>;
			qcom,sc-deb-cycles = <8>;
			qcom,int-pwm-freq-khz = <505>;
			qcom,en-brake;
			qcom,brake-pattern = [03 03 00 00];
			qcom,use-play-irq;
			qcom,use-sc-irq;
			qcom,wave-samples = [3e 3e 3e 3e 3e 3e 3e 3e];
			qcom,wave-rep-cnt = <1>;
			qcom,wave-samp-rep-cnt = <1>;
			qcom,lra-high-z = "opt1";
			qcom,lra-auto-res-mode = "qwd";
			qcom,lra-res-cal-period = <4>;
		};