input: introduce support for Qualcomm SPMI haptics

This series introduces a driver for the SPMI haptics hardware block found in Qualcomm PMICs. SPMI haptics support LRA (Linear Resonant Actuator) style haptics, as well as ERM (Eccentric Rotating Mass). It also supports several modes of driving the haptics, e.g. by loading the pattern to play into an internal buffer, or using PWM.

More information about the hardware can be found here:

        https://gitlab.com/sdm845-mainline/linux/-/wikis/PMI8998-QPNP-Haptics

This driver has been written based on downstream sources as no public documentation is available. It includes initial support for LRA haptics in buffer mode, this combination seems to be the most common and will enable haptics on the OnePlus 6 and 6T, PocoPhone F1, OnePlus 5 and several other Qualcomm devices with mainline kernel support.

The driver is implemented using the ff-memless (forcefeedback) input framework and makes an attempt to control the strength of vibration relative to the magnitude set from userspace.

Changes since v5:
- Fix dt schema errors
- Fix typo (thanks Vincent)

Changes since v4:
- Significant rewrite and cleanup
- switch to dev_err_probe()
- Run through clang-format

Changes since v3:
- Adjust example DTS to avoid creating new warnings in dt_binding_check
- Address warnings from kernel test robot.

Changes since v2:
- Addressed Rob's comments on dt-bindings (I'm not sure what to do about the pmic compatible?)
- Fixed some typos

Changes since v1:
- Replace old QPNP naming with SPMI
- Address Bjorn's comments on the driver, various style and code cleanups
- Address Bjorn's comments on the DT bindings and DTS
- Pickup patches from Joel and Jami to enable haptics on the OnePlus 5 and Poco F1.

Caleb Connolly (2):
dt-bindings: input: document Qualcomm PMI8998 haptics driver
input: add Qualcomm SPMI haptics driver

 .../bindings/input/qcom,pmi8998-haptics.yaml  |  71 ++
 drivers/input/misc/Kconfig                    |  15 +
 drivers/input/misc/Makefile                   |   1 +
 drivers/input/misc/qcom-pmi8998-haptics.c     | 690 ++++++++++++++++++
 4 files changed, 777 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/qcom,pmi8998-haptics.yaml
 create mode 100644 drivers/input/misc/qcom-pmi8998-haptics.c

--
2.38.0

Add bindings for qcom PMIC PMI8998 haptics driver.

---
 .../bindings/input/qcom,pmi8998-haptics.yaml  | 71 +++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/qcom,pmi8998-haptics.yaml

new file mode 100644
index 000000000000..9f51c527595c
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2020 Unisoc Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/qcom,pmi8998-haptics.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm PMI8998/PM660 Haptics
+
+maintainers:
+  - Caleb Connolly <[email protected]>
+
+description: |
+  Qualcomm SPMI haptics is a peripheral on some QTI PMICs. It supports linear resonant
+  actuators and eccentric rotating mass type haptics commonly found in mobile devices.
+  It supports multiple sources of wave data such as an internal buffer, direct play
+  (from kernel or userspace) as well as an audio output mode.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qcom,pmi8998-haptics
+          - qcom,pm660-charger
+          - qcom,pmi8996-haptics
+          - qcom,pmi8941-haptics
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 2
+
+  interrupt-names:
+    items:
+      - const: short
+      - const: play
+
+  qcom,wave-play-rate-us:
+    description: |
+      Wave sample duration in microseconds, 1/f where f
+      is the resonant frequency of the actuator.
+    minimum: 0
+    maximum: 20475
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - qcom,wave-play-rate-us
+
+additionalProperties: false
+
+examples:
+  - |
+      #include <dt-bindings/interrupt-controller/irq.h>
+
+      spmi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        pmi8998_haptics: haptics@c000 {
+          compatible = "qcom,pmi8998-haptics";
+          reg = <0xc000>;
+
+          interrupts = <0x3 0xc0 0x0 IRQ_TYPE_EDGE_BOTH>,
+                      <0x3 0xc0 0x1 IRQ_TYPE_EDGE_BOTH>;
+          interrupt-names = "short", "play";
+
+          qcom,wave-play-rate-us = <4255>;
+        };
+      };

--
2.38.0

Best regards,
Krzysztof