[PATCH v4 0/6] Add spi-hid, transport for HID over SPI bus

[PATCH v4 0/6] Add spi-hid, transport for HID over SPI bus

[Dmitry Antipov]

Surface Duo devices use a touch digitizer that communicates to the main
SoC via SPI and presents itself as a HID device. This patch's goal is to
add the spi-hid transport driver to drivers/hid. The driver follows the
publically available HID Over SPI Protocol Specification version 1.0.

The specification is available at
https://www.microsoft.com/en-us/download/details.aspx?id=103325.

In the initial commits there are some HID core changes to support a SPI
device, a change to HID documentation, HID over SPI Device Tree
bindings, and finally the SPI HID transport driver.

Dmitry Antipov (6):
  HID: Add BUS_SPI support when printing out device info in
    hid_connect()
  HID: define HID_SPI_DEVICE macro in hid.h
  Documentation: DT bindings for Microsoft G6 Touch Digitizer
  Documentation: Correction in HID output_report callback description.
  HID: add spi-hid, transport driver for HID over SPI bus
  Defconfig: add CONFIG_SPI_HID=m

 .../input/microsoft,g6-touch-digitizer.yaml   |  105 ++
 Documentation/hid/hid-transport.rst           |    4 +-
 arch/arm64/configs/defconfig                  |    1 +
 drivers/hid/Kconfig                           |    2 +
 drivers/hid/Makefile                          |    1 +
 drivers/hid/hid-core.c                        |    3 +
 drivers/hid/spi-hid/Kconfig                   |   25 +
 drivers/hid/spi-hid/Makefile                  |   12 +
 drivers/hid/spi-hid/spi-hid-core.c            | 1326 +++++++++++++++++
 drivers/hid/spi-hid/spi-hid-core.h            |  188 +++
 drivers/hid/spi-hid/spi-hid-of.c              |  141 ++
 drivers/hid/spi-hid/spi-hid-of.h              |   30 +
 drivers/hid/spi-hid/spi-hid_trace.h           |  194 +++
 drivers/hid/spi-hid/trace.c                   |    9 +
 include/linux/hid.h                           |    2 +
 15 files changed, 2041 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
 create mode 100644 drivers/hid/spi-hid/Kconfig
 create mode 100644 drivers/hid/spi-hid/Makefile
 create mode 100644 drivers/hid/spi-hid/spi-hid-core.c
 create mode 100644 drivers/hid/spi-hid/spi-hid-core.h
 create mode 100644 drivers/hid/spi-hid/spi-hid-of.c
 create mode 100644 drivers/hid/spi-hid/spi-hid-of.h
 create mode 100644 drivers/hid/spi-hid/spi-hid_trace.h
 create mode 100644 drivers/hid/spi-hid/trace.c

-- 
2.25.1

[PATCH v4 1/6] HID: Add BUS_SPI support when printing out device info in hid_connect()

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

If connecting a hid_device with bus field indicating BUS_SPI print out
"SPI" in the debug print.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 drivers/hid/hid-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index dbed2524fd47..65350ad985fe 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2005,6 +2005,9 @@ int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
 	case BUS_I2C:
 		bus = "I2C";
 		break;
+	case BUS_SPI:
+		bus = "SPI";
+		break;
 	case BUS_VIRTUAL:
 		bus = "VIRTUAL";
 		break;
-- 
2.25.1

[PATCH v4 2/6] HID: define HID_SPI_DEVICE macro in hid.h

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

Macro sets the bus field to BUS_SPI and uses arguments to set vendor
product fields.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 include/linux/hid.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/hid.h b/include/linux/hid.h
index f453be385bd4..1f134c8f8972 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -684,6 +684,8 @@ struct hid_descriptor {
 	.bus = BUS_BLUETOOTH, .vendor = (ven), .product = (prod)
 #define HID_I2C_DEVICE(ven, prod)				\
 	.bus = BUS_I2C, .vendor = (ven), .product = (prod)
+#define HID_SPI_DEVICE(ven, prod)				\
+	.bus = BUS_SPI, .vendor = (ven), .product = (prod)
 
 #define HID_REPORT_ID(rep) \
 	.report_type = (rep)
-- 
2.25.1

[PATCH v4 3/6] Documentation: DT bindings for Microsoft G6 Touch Digitizer

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

Documentation describes the required and optional properties for
implementing Device Tree for a Microsoft G6 Touch Digitizer that
supports HID over SPI Protocol 1.0 specification.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 .../input/microsoft,g6-touch-digitizer.yaml   | 105 ++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml

diff --git a/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
new file mode 100644
index 000000000000..e516717527e9
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/microsoft,g6-touch-digitizer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microsoft G6 Touch Digitizer
+
+maintainers:
+  - Dmitry Antipov <dmanti@microsoft.com>
+
+description: |
+  Microsoft G6 touch digitizer is a HID over SPI device supporting HID Over SPI
+  Protocol Specification 1.0, available at
+  https://www.microsoft.com/en-us/download/details.aspx?id=103325.
+
+properties:
+  compatible:
+    oneOf:
+      - const: microsoft,g6-touch-digitizer
+      - items:
+        - const: microsoft,g6-touch-digitizer
+        - const: hid-over-spi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+    description:
+      GPIO specifier for the digitizer's reset pin (active low). The line must
+      be flagged with GPIO_ACTIVE_LOW.
+
+  vdd-supply:
+    description:
+      Regulator for the VDD supply voltage.
+
+  input-report-header-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      This property and the rest are described in HID Over SPI Protocol Spec 1.0
+
+  input-report-body-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  output-report-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  read-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  write-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  hid-over-spi-flags:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  post-power-on-delay-ms:
+    description:
+      Optional time in ms required by the device after enabling its regulators
+      or powering it on, before it is ready for communication.
+
+  minimal-reset-delay-ms:
+    description:
+      Optional minimum amount of time in ms that device needs to be in reset
+      state for the reset to take effect.
+
+required:
+  - compatible
+  - interrupts
+  - reset-gpios
+  - vdd-supply
+  - input-report-header-address
+  - input-report-body-address
+  - output-report-address
+  - read-opcode
+  - write-opcode
+  - hid-over-spi-flags
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    spi-hid-dev0 {
+      compatible = "microsoft,g6-touch-digitizer", "hid-over-spi";
+      reg = <0>;
+      interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
+      reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
+      vdd-supply = <&pm8350c_l3>;
+      pinctrl-names = "default";
+      pinctrl-0 = <&ts_d6_reset_assert &ts_d6_int_bias>;
+      input-report-header-address = <0x1000>;
+      input-report-body-address = <0x1004>;
+      output-report-address = <0x2000>;
+      read-opcode = <0x0b>;
+      write-opcode = <0x02>;
+      hid-over-spi-flags = <0x00>;
+      post-power-on-delay-ms = <5>;
+      minimal-reset-delay-ms = <5>;
+    };
-- 
2.25.1

[PATCH v4 4/6] Documentation: Correction in HID output_report callback description.

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

Originally output_report callback was described as must-be asynchronous,
but that is not the case in some implementations, namely i2c-hid.
Correct the documentation to say that it may be asynchronous.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 Documentation/hid/hid-transport.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/hid/hid-transport.rst b/Documentation/hid/hid-transport.rst
index 6f1692da296c..2008cf432af1 100644
--- a/Documentation/hid/hid-transport.rst
+++ b/Documentation/hid/hid-transport.rst
@@ -327,8 +327,8 @@ The available HID callbacks are:
 
    Send raw output report via intr channel. Used by some HID device drivers
    which require high throughput for outgoing requests on the intr channel. This
-   must not cause SET_REPORT calls! This must be implemented as asynchronous
-   output report on the intr channel!
+   must not cause SET_REPORT calls! This call might be asynchronous, so the
+   caller should not expect an immediate response!
 
    ::
 
-- 
2.25.1

[PATCH v4 5/6] HID: add spi-hid, transport driver for HID over SPI bus

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

This driver follows HID Over SPI Protocol Specification 1.0 available at
https://www.microsoft.com/en-us/download/details.aspx?id=103325. The
initial version of the driver does not support: 1) multi-fragment input
reports, 2) sending GET_INPUT and COMMAND output report types and
processing their respective acknowledge input reports, and 3) device
sleep power state.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 drivers/hid/Kconfig                 |    2 +
 drivers/hid/Makefile                |    1 +
 drivers/hid/spi-hid/Kconfig         |   25 +
 drivers/hid/spi-hid/Makefile        |   12 +
 drivers/hid/spi-hid/spi-hid-core.c  | 1326 +++++++++++++++++++++++++++
 drivers/hid/spi-hid/spi-hid-core.h  |  188 ++++
 drivers/hid/spi-hid/spi-hid-of.c    |  141 +++
 drivers/hid/spi-hid/spi-hid-of.h    |   30 +
 drivers/hid/spi-hid/spi-hid_trace.h |  194 ++++
 drivers/hid/spi-hid/trace.c         |    9 +
 10 files changed, 1928 insertions(+)
 create mode 100644 drivers/hid/spi-hid/Kconfig
 create mode 100644 drivers/hid/spi-hid/Makefile
 create mode 100644 drivers/hid/spi-hid/spi-hid-core.c
 create mode 100644 drivers/hid/spi-hid/spi-hid-core.h
 create mode 100644 drivers/hid/spi-hid/spi-hid-of.c
 create mode 100644 drivers/hid/spi-hid/spi-hid-of.h
 create mode 100644 drivers/hid/spi-hid/spi-hid_trace.h
 create mode 100644 drivers/hid/spi-hid/trace.c

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index a7c78ac96270..cd2c10703fcf 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -1262,6 +1262,8 @@ source "drivers/hid/usbhid/Kconfig"
 
 source "drivers/hid/i2c-hid/Kconfig"
 
+source "drivers/hid/spi-hid/Kconfig"
+
 source "drivers/hid/intel-ish-hid/Kconfig"
 
 source "drivers/hid/amd-sfh-hid/Kconfig"
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 55a6fa3eca5a..caf418dda343 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -144,6 +144,7 @@ obj-$(CONFIG_USB_MOUSE)		+= usbhid/
 obj-$(CONFIG_USB_KBD)		+= usbhid/
 
 obj-$(CONFIG_I2C_HID_CORE)	+= i2c-hid/
+obj-$(CONFIG_SPI_HID)		+= spi-hid/
 
 obj-$(CONFIG_INTEL_ISH_HID)	+= intel-ish-hid/
 obj-$(INTEL_ISH_FIRMWARE_DOWNLOADER)	+= intel-ish-hid/
diff --git a/drivers/hid/spi-hid/Kconfig b/drivers/hid/spi-hid/Kconfig
new file mode 100644
index 000000000000..37302d658162
--- /dev/null
+++ b/drivers/hid/spi-hid/Kconfig
@@ -0,0 +1,25 @@
+#
+# Copyright (c) 2021 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 as published by
+# the Free Software Foundation.
+#
+menu "SPI HID support"
+	depends on SPI
+
+config SPI_HID
+	tristate "HID over SPI transport layer"
+	default n
+	depends on SPI && INPUT && OF
+	select HID
+	help
+	  Say Y here if you use a keyboard, a touchpad, a touchscreen, or any
+	  other HID based devices which is connected to your computer via SPI.
+
+	  If unsure, say N.
+
+	  This support is also available as a module.  If so, the module
+	  will be called spi-hid.
+
+endmenu
diff --git a/drivers/hid/spi-hid/Makefile b/drivers/hid/spi-hid/Makefile
new file mode 100644
index 000000000000..b9f73982b956
--- /dev/null
+++ b/drivers/hid/spi-hid/Makefile
@@ -0,0 +1,12 @@
+#
+# Copyright (c) 2021 Microsoft Corporation
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 as published by
+# the Free Software Foundation.
+#
+# Makefile for the HID over SPI transport driver
+#
+CFLAGS_trace.o = -I$(src)
+obj-$(CONFIG_SPI_HID)	+= spi-hid.o
+spi-hid-objs := spi-hid-core.o spi-hid-of.o trace.o
diff --git a/drivers/hid/spi-hid/spi-hid-core.c b/drivers/hid/spi-hid/spi-hid-core.c
new file mode 100644
index 000000000000..8a29bfe40590
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-core.c
@@ -0,0 +1,1326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID over SPI protocol implementation
+ *
+ * Copyright (c) 2021 Microsoft Corporation
+ *
+ * This code is partly based on "HID over I2C protocol implementation:
+ *
+ *  Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ *  Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ *  Copyright (c) 2012 Red Hat, Inc
+ *
+ *  which in turn is partly based on "USB HID support for Linux":
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2007-2008 Oliver Neukum
+ *  Copyright (c) 2006-2010 Jiri Kosina
+ */
+
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/string.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#include "spi-hid-core.h"
+#include "spi-hid_trace.h"
+#include "spi-hid-of.h"
+#include "../hid-ids.h"
+
+#define SPI_HID_MAX_RESET_ATTEMPTS 3
+
+static struct hid_ll_driver spi_hid_ll_driver;
+
+static void spi_hid_populate_read_approvals(struct spi_hid_of_config *conf,
+	u8 *header_buf, u8 *body_buf)
+{
+	header_buf[0] = conf->read_opcode;
+	header_buf[1] = (conf->input_report_header_address >> 16) & 0xff;
+	header_buf[2] =	(conf->input_report_header_address >> 8) & 0xff;
+	header_buf[3] =	(conf->input_report_header_address >> 0) & 0xff;
+	header_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT;
+
+	body_buf[0] = conf->read_opcode;
+	body_buf[1] = (conf->input_report_body_address >> 16) & 0xff;
+	body_buf[2] = (conf->input_report_body_address >> 8) & 0xff;
+	body_buf[3] = (conf->input_report_body_address >> 0) & 0xff;
+	body_buf[4] = SPI_HID_READ_APPROVAL_CONSTANT;
+}
+
+static void spi_hid_parse_dev_desc(struct spi_hid_device_desc_raw *raw,
+					struct spi_hid_device_descriptor *desc)
+{
+	desc->hid_version = le16_to_cpu(raw->bcdVersion);
+	desc->report_descriptor_length = le16_to_cpu(raw->wReportDescLength);
+	desc->max_input_length = le16_to_cpu(raw->wMaxInputLength);
+	desc->max_output_length = le16_to_cpu(raw->wMaxOutputLength);
+
+	/* FIXME: multi-fragment not supported, field below not used */
+	desc->max_fragment_length = le16_to_cpu(raw->wMaxFragmentLength);
+
+	desc->vendor_id = le16_to_cpu(raw->wVendorID);
+	desc->product_id = le16_to_cpu(raw->wProductID);
+	desc->version_id = le16_to_cpu(raw->wVersionID);
+	desc->no_output_report_ack = le16_to_cpu(raw->wFlags) & BIT(0);
+}
+
+static void spi_hid_populate_input_header(u8 *buf,
+		struct spi_hid_input_header *header)
+{
+	header->version            = buf[0] & 0xf;
+	header->report_length      = le16_to_cpu((buf[1] | ((buf[2] & 0x3f) << 8)) * 4);
+	header->last_fragment_flag = (buf[2] & 0x40) >> 6;
+	header->sync_const         = buf[3];
+}
+
+static void spi_hid_populate_input_body(u8 *buf,
+		struct spi_hid_input_body *body)
+{
+	body->report_type = buf[0];
+	body->content_length = le16_to_cpu(buf[1] | (buf[2] << 8));
+	body->content_id = buf[3];
+}
+
+static void spi_hid_input_report_prepare(struct spi_hid_input_buf *buf,
+		struct spi_hid_input_report *report)
+{
+	struct spi_hid_input_header header;
+	struct spi_hid_input_body body;
+
+	spi_hid_populate_input_header(buf->header, &header);
+	spi_hid_populate_input_body(buf->body, &body);
+	report->report_type = body.report_type;
+	report->content_length = body.content_length;
+	report->content_id = body.content_id;
+	report->content = buf->content;
+}
+
+static void spi_hid_populate_output_header(u8 *buf,
+		struct spi_hid_of_config *conf,
+		struct spi_hid_output_report *report)
+{
+	buf[0] = conf->write_opcode;
+	buf[1] = (conf->output_report_address >> 16) & 0xff;
+	buf[2] = (conf->output_report_address >> 8) & 0xff;
+	buf[3] = (conf->output_report_address >> 0) & 0xff;
+	buf[4] = report->report_type;
+	buf[5] = report->content_length & 0xff;
+	buf[6] = (report->content_length >> 8) & 0xff;
+	buf[7] = report->content_id;
+}
+
+static int spi_hid_input_sync(struct spi_hid *shid, void *buf, u16 length,
+				bool is_header)
+{
+	int ret;
+	struct device *dev = &shid->spi->dev;
+
+	shid->input_transfer[0].tx_buf = is_header ? shid->read_approval_header :
+						shid->read_approval_body;
+	shid->input_transfer[0].len = SPI_HID_READ_APPROVAL_LEN;
+
+	shid->input_transfer[1].rx_buf = buf;
+	shid->input_transfer[1].len = length;
+
+	spi_message_init_with_transfers(&shid->input_message,
+			shid->input_transfer, 2);
+
+	trace_spi_hid_input_sync(shid,
+			shid->input_transfer[0].tx_buf,
+			shid->input_transfer[0].len,
+			shid->input_transfer[1].rx_buf,
+			shid->input_transfer[1].len, 0);
+
+	ret = spi_sync(shid->spi, &shid->input_message);
+	if (ret) {
+		dev_err(dev, "Error starting async transfer: %d, resetting\n",
+									ret);
+		shid->bus_error_count++;
+		shid->bus_last_error = ret;
+		schedule_work(&shid->error_work);
+	}
+
+	return ret;
+}
+
+static int spi_hid_output(struct spi_hid *shid, void *buf, u16 length)
+{
+	struct spi_transfer transfer;
+	struct spi_message message;
+	int ret;
+
+	memset(&transfer, 0, sizeof(transfer));
+
+	transfer.tx_buf = buf;
+	transfer.len = length;
+
+	spi_message_init_with_transfers(&message, &transfer, 1);
+
+	trace_spi_hid_output_begin(shid, transfer.tx_buf,
+			transfer.len, NULL, 0, 0);
+
+	ret = spi_sync(shid->spi, &message);
+
+	trace_spi_hid_output_end(shid, transfer.tx_buf,
+			transfer.len, NULL, 0, ret);
+
+	if (ret) {
+		shid->bus_error_count++;
+		shid->bus_last_error = ret;
+	}
+
+	return ret;
+}
+
+static const char *const spi_hid_power_mode_string(u8 power_state)
+{
+	switch (power_state) {
+	case SPI_HID_POWER_MODE_ON:
+		return "d0";
+	case SPI_HID_POWER_MODE_SLEEP:
+		return "d2";
+	case SPI_HID_POWER_MODE_OFF:
+		return "d3";
+	case SPI_HID_POWER_MODE_WAKING_SLEEP:
+		return "d3*";
+	default:
+		return "unknown";
+	}
+}
+
+static void spi_hid_suspend(struct spi_hid *shid)
+{
+	int ret;
+	struct device *dev = &shid->spi->dev;
+
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF)
+		return;
+
+	if (shid->irq_enabled) {
+		disable_irq(shid->spi->irq);
+		shid->irq_enabled = false;
+	} else {
+		dev_err(dev, "%s called with interrupt already disabled\n",
+								__func__);
+	}
+
+	shid->ready = false;
+
+	spi_hid_of_assert_reset(&shid->conf);
+
+	ret = spi_hid_of_power_down(&shid->conf);
+	if (ret) {
+		dev_err(dev, "%s: could not power down\n", __func__);
+		shid->regulator_error_count++;
+		shid->regulator_last_error = ret;
+		return;
+	}
+
+	shid->power_state = SPI_HID_POWER_MODE_OFF;
+}
+
+static void spi_hid_resume(struct spi_hid *shid)
+{
+	int ret;
+	struct device *dev = &shid->spi->dev;
+
+	if (shid->power_state == SPI_HID_POWER_MODE_ON)
+		return;
+
+	if (!shid->irq_enabled) {
+		enable_irq(shid->spi->irq);
+		shid->irq_enabled = true;
+	} else {
+		dev_err(dev, "%s called with interrupt already enabled\n",
+								__func__);
+	}
+
+	ret = spi_hid_of_power_up(&shid->conf);
+	if (ret) {
+		dev_err(dev, "%s: could not power up\n", __func__);
+		shid->regulator_error_count++;
+		shid->regulator_last_error = ret;
+		return;
+	}
+	shid->power_state = SPI_HID_POWER_MODE_ON;
+
+	spi_hid_of_deassert_reset(&shid->conf);
+}
+
+static struct hid_device *spi_hid_disconnect_hid(struct spi_hid *shid)
+{
+	struct hid_device *hid = shid->hid;
+
+	shid->hid = NULL;
+
+	return hid;
+}
+
+static void spi_hid_stop_hid(struct spi_hid *shid)
+{
+	struct hid_device *hid;
+
+	hid = spi_hid_disconnect_hid(shid);
+	if (hid) {
+		cancel_work_sync(&shid->create_device_work);
+		cancel_work_sync(&shid->refresh_device_work);
+		hid_destroy_device(hid);
+	}
+}
+
+static void spi_hid_error_work(struct work_struct *work)
+{
+	struct spi_hid *shid = container_of(work, struct spi_hid, error_work);
+	struct device *dev = &shid->spi->dev;
+	int ret;
+
+	mutex_lock(&shid->power_lock);
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF)
+		goto out;
+
+	if (shid->attempts++ >= SPI_HID_MAX_RESET_ATTEMPTS) {
+		dev_err(dev, "unresponsive device, aborting.\n");
+		spi_hid_stop_hid(shid);
+		spi_hid_of_assert_reset(&shid->conf);
+		ret = spi_hid_of_power_down(&shid->conf);
+		if (ret) {
+			dev_err(dev, "failed to disable regulator\n");
+			shid->regulator_error_count++;
+			shid->regulator_last_error = ret;
+		}
+		goto out;
+	}
+
+	trace_spi_hid_error_work(shid);
+
+	shid->ready = false;
+
+	spi_hid_of_assert_reset(&shid->conf);
+
+	shid->power_state = SPI_HID_POWER_MODE_OFF;
+	cancel_work_sync(&shid->reset_response_work);
+
+	spi_hid_of_sleep_minimal_reset_delay(&shid->conf);
+
+	shid->power_state = SPI_HID_POWER_MODE_ON;
+
+	spi_hid_of_deassert_reset(&shid->conf);
+out:
+	mutex_unlock(&shid->power_lock);
+}
+
+static int spi_hid_send_output_report(struct spi_hid *shid,
+		struct spi_hid_output_report *report)
+{
+	struct spi_hid_output_buf *buf = &shid->output;
+	struct device *dev = &shid->spi->dev;
+	u16 report_length;
+	u16 padded_length;
+	u8 padding;
+	int ret;
+
+	if (report->content_length > shid->desc.max_output_length) {
+		dev_err(dev, "Output report too big, content_length 0x%x\n",
+						report->content_length);
+		ret = -E2BIG;
+		goto out;
+	}
+
+	spi_hid_populate_output_header(buf->header, &shid->conf, report);
+
+	if (report->content_length)
+		memcpy(&buf->content, report->content, report->content_length);
+
+	report_length = sizeof(buf->header) + report->content_length;
+	padded_length = round_up(report_length,	4);
+	padding = padded_length - report_length;
+	memset(&buf->content[report->content_length], 0, padding);
+
+	ret = spi_hid_output(shid, buf, padded_length);
+	if (ret) {
+		dev_err(dev, "Failed output transfer\n");
+		goto out;
+	}
+
+	return 0;
+
+out:
+	return ret;
+}
+
+static int spi_hid_sync_request(struct spi_hid *shid,
+		struct spi_hid_output_report *report)
+{
+	struct device *dev = &shid->spi->dev;
+	int ret = 0;
+
+	ret = spi_hid_send_output_report(shid, report);
+	if (ret) {
+		dev_err(dev, "Failed to transfer output report\n");
+		return ret;
+	}
+
+	mutex_unlock(&shid->output_lock);
+	ret = wait_for_completion_interruptible_timeout(&shid->output_done,
+			msecs_to_jiffies(1000));
+	mutex_lock(&shid->output_lock);
+	if (ret == 0) {
+		dev_err(dev, "Response timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/**
+ * Handle the reset response from the FW by sending a request for the device
+ * descriptor.
+ */
+static void spi_hid_reset_response_work(struct work_struct *work)
+{
+	struct spi_hid *shid =
+		container_of(work, struct spi_hid, reset_response_work);
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = SPI_HID_OUTPUT_REPORT_TYPE_DEVICE_DESC_REQUEST,
+		.content_length = 0x0,
+		.content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST,
+		.content = NULL,
+	};
+	int ret;
+
+	trace_spi_hid_reset_response_work(shid);
+
+	if (shid->ready) {
+		dev_err(dev, "Spontaneous FW reset!");
+		shid->ready = false;
+		shid->dir_count++;
+	}
+
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF)
+		return;
+
+	if (flush_work(&shid->create_device_work))
+		dev_err(dev, "Reset handler waited for create_device_work");
+
+	if (flush_work(&shid->refresh_device_work))
+		dev_err(dev, "Reset handler waited for refresh_device_work");
+
+	mutex_lock(&shid->output_lock);
+	ret = spi_hid_sync_request(shid, &report);
+	mutex_unlock(&shid->output_lock);
+	if (ret) {
+		dev_WARN_ONCE(dev, true,
+				"Failed to send device descriptor request\n");
+		schedule_work(&shid->error_work);
+	}
+}
+
+static int spi_hid_input_report_handler(struct spi_hid *shid,
+		struct spi_hid_input_buf *buf)
+{
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_input_report r;
+	int ret;
+
+	trace_spi_hid_input_report_handler(shid);
+
+	if (!shid->ready || shid->refresh_in_progress || !shid->hid)
+		return 0;
+
+	spi_hid_input_report_prepare(buf, &r);
+
+	ret = hid_input_report(shid->hid, HID_INPUT_REPORT,
+			r.content - 1,
+			r.content_length + 1, 1);
+
+	if (ret == -ENODEV || ret == -EBUSY) {
+		dev_err(dev, "ignoring report --> %d\n", ret);
+		return 0;
+	} else if (ret) {
+		dev_err(dev, "Bad input report, error %d\n", ret);
+	}
+
+	return ret;
+}
+
+static void spi_hid_response_handler(struct spi_hid *shid,
+		struct spi_hid_input_buf *buf)
+{
+	trace_spi_hid_response_handler(shid);
+
+	/* completion_done returns 0 if there are waiters, otherwise 1 */
+	if (completion_done(&shid->output_done)) {
+		dev_err(&shid->spi->dev, "Unexpected response report\n");
+	} else {
+		if (shid->input.body[0] ==
+				SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC ||
+			shid->input.body[0] ==
+				SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP) {
+			size_t response_length = (shid->input.body[1] |
+					(shid->input.body[2] << 8)) +
+					sizeof(shid->input.body);
+			memcpy(shid->response.body, shid->input.body,
+							response_length);
+		}
+		complete(&shid->output_done);
+	}
+}
+
+/*
+ * This function returns the length of the report descriptor, or a negative
+ * error code if something went wrong.
+ */
+static int spi_hid_report_descriptor_request(struct spi_hid *shid)
+{
+	int ret;
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = SPI_HID_OUTPUT_REPORT_TYPE_REPORT_DESC_REQUEST,
+		.content_length = 0,
+		.content_id = SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST,
+		.content = NULL,
+	};
+
+	ret =  spi_hid_sync_request(shid, &report);
+	if (ret) {
+		dev_err(dev,
+			"Expected report descriptor not received! Error %d\n",
+			ret);
+		schedule_work(&shid->error_work);
+		goto out;
+	}
+
+	ret = (shid->response.body[1] | (shid->response.body[2] << 8));
+	if (ret != shid->desc.report_descriptor_length) {
+		ret = min_t(unsigned int, ret,
+			shid->desc.report_descriptor_length);
+		dev_err(dev,
+			"Received report descriptor length doesn't match device descriptor field, using min of the two: %d\n",
+			ret);
+	}
+out:
+	return ret;
+}
+
+static void spi_hid_process_input_report(struct spi_hid *shid,
+		struct spi_hid_input_buf *buf)
+{
+	struct spi_hid_input_header header;
+	struct spi_hid_input_body body;
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_device_desc_raw *raw;
+	int ret;
+
+	trace_spi_hid_process_input_report(shid);
+
+	spi_hid_populate_input_header(buf->header, &header);
+	spi_hid_populate_input_body(buf->body, &body);
+
+	if (body.content_length > header.report_length) {
+		dev_err(dev, "Bad body length %d > %d\n", body.content_length,
+							header.report_length);
+		schedule_work(&shid->error_work);
+		return;
+	}
+
+	switch (body.report_type) {
+	case SPI_HID_INPUT_REPORT_TYPE_DATA:
+		ret = spi_hid_input_report_handler(shid, buf);
+		if (ret)
+			schedule_work(&shid->error_work);
+		break;
+	case SPI_HID_INPUT_REPORT_TYPE_RESET_RESP:
+		schedule_work(&shid->reset_response_work);
+		break;
+	case SPI_HID_INPUT_REPORT_TYPE_DEVICE_DESC:
+		/* Mark the completion done to avoid timeout */
+		spi_hid_response_handler(shid, buf);
+
+		/* Reset attempts at every device descriptor fetch */
+		shid->attempts = 0;
+
+		raw = (struct spi_hid_device_desc_raw *)buf->content;
+
+		/* Validate device descriptor length before parsing */
+		if (body.content_length != SPI_HID_DEVICE_DESCRIPTOR_LENGTH) {
+			dev_err(dev,
+				"Invalid content length %d, expected %d\n",
+				body.content_length,
+				SPI_HID_DEVICE_DESCRIPTOR_LENGTH);
+			schedule_work(&shid->error_work);
+			break;
+		}
+
+		if (le16_to_cpu(raw->wDeviceDescLength) !=
+					SPI_HID_DEVICE_DESCRIPTOR_LENGTH) {
+			dev_err(dev,
+				"Invalid wDeviceDescLength %d, expected %d\n",
+				raw->wDeviceDescLength,
+				SPI_HID_DEVICE_DESCRIPTOR_LENGTH);
+			schedule_work(&shid->error_work);
+			break;
+		}
+
+		spi_hid_parse_dev_desc(raw, &shid->desc);
+
+		if (shid->desc.hid_version != SPI_HID_SUPPORTED_VERSION) {
+			dev_err(dev,
+				"Unsupported device descriptor version %4x\n",
+				shid->desc.hid_version);
+			schedule_work(&shid->error_work);
+			break;
+		}
+
+		if (!shid->hid)
+			schedule_work(&shid->create_device_work);
+		else
+			schedule_work(&shid->refresh_device_work);
+
+		break;
+	case SPI_HID_INPUT_REPORT_TYPE_SET_OUTPUT_REPORT_RESP:
+		if (shid->desc.no_output_report_ack) {
+			dev_err(dev, "Unexpected output report response\n");
+			break;
+		}
+		fallthrough;
+	case SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP:
+	case SPI_HID_INPUT_REPORT_TYPE_SET_FEATURE_RESP:
+		if (!shid->ready) {
+			dev_err(dev,
+				"Unexpected response report while not ready: 0x%x\n",
+				body.report_type);
+			break;
+		}
+		fallthrough;
+	case SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC:
+		spi_hid_response_handler(shid, buf);
+		break;
+	/*
+	 * FIXME: sending GET_INPUT and COMMAND reports not supported, thus
+	 * throw away responses to those, they should never come.
+	 */
+	case SPI_HID_INPUT_REPORT_TYPE_GET_INPUT_REPORT_RESP:
+	case SPI_HID_INPUT_REPORT_TYPE_COMMAND_RESP:
+		dev_err(dev, "Not a supported report type: 0x%x\n",
+							body.report_type);
+		break;
+	default:
+		dev_err(dev, "Unknown input report: 0x%x\n",
+							body.report_type);
+		schedule_work(&shid->error_work);
+		break;
+	}
+}
+
+static int spi_hid_bus_validate_header(struct spi_hid *shid,
+					struct spi_hid_input_header *header)
+{
+	struct device *dev = &shid->spi->dev;
+
+	if (header->version != SPI_HID_INPUT_HEADER_VERSION) {
+		dev_err(dev, "Unknown input report version (v 0x%x)\n",
+				header->version);
+		return -EINVAL;
+	}
+
+	if (shid->desc.max_input_length != 0 &&
+			header->report_length > shid->desc.max_input_length) {
+		dev_err(dev, "Input report body size %u > max expected of %u\n",
+				header->report_length,
+				shid->desc.max_input_length);
+		return -EMSGSIZE;
+	}
+
+	if (header->last_fragment_flag != 1) {
+		dev_err(dev, "Multi-fragment reports not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (header->sync_const != SPI_HID_INPUT_HEADER_SYNC_BYTE) {
+		dev_err(dev, "Invalid input report sync constant (0x%x)\n",
+				header->sync_const);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int spi_hid_create_device(struct spi_hid *shid)
+{
+	struct hid_device *hid;
+	struct device *dev = &shid->spi->dev;
+	int ret;
+
+	hid = hid_allocate_device();
+
+	if (IS_ERR(hid)) {
+		dev_err(dev, "Failed to allocate hid device: %ld\n",
+				PTR_ERR(hid));
+		ret = PTR_ERR(hid);
+		return ret;
+	}
+
+	hid->driver_data = shid->spi;
+	hid->ll_driver = &spi_hid_ll_driver;
+	hid->dev.parent = &shid->spi->dev;
+	hid->bus = BUS_SPI;
+	hid->version = shid->desc.hid_version;
+	hid->vendor = shid->desc.vendor_id;
+	hid->product = shid->desc.product_id;
+
+	snprintf(hid->name, sizeof(hid->name), "spi %04hX:%04hX",
+			hid->vendor, hid->product);
+	strscpy(hid->phys, dev_name(&shid->spi->dev), sizeof(hid->phys));
+
+	shid->hid = hid;
+
+	ret = hid_add_device(hid);
+	if (ret) {
+		dev_err(dev, "Failed to add hid device: %d\n", ret);
+		/*
+		 * We likely got here because report descriptor request timed
+		 * out. Let's disconnect and destroy the hid_device structure.
+		 */
+		hid = spi_hid_disconnect_hid(shid);
+		if (hid)
+			hid_destroy_device(hid);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void spi_hid_create_device_work(struct work_struct *work)
+{
+	struct spi_hid *shid =
+		container_of(work, struct spi_hid, create_device_work);
+	struct device *dev = &shid->spi->dev;
+	u8 prev_state = shid->power_state;
+	int ret;
+
+	trace_spi_hid_create_device_work(shid);
+
+	mutex_lock(&shid->power_lock);
+	if (prev_state == SPI_HID_POWER_MODE_OFF) {
+		dev_err(dev, "%s: Powered off, returning", __func__);
+		goto out;
+	}
+
+	ret = spi_hid_create_device(shid);
+	if (ret) {
+		dev_err(dev, "%s: Failed to create hid device\n", __func__);
+		goto out;
+	}
+
+	spi_hid_suspend(shid);
+
+out:
+	mutex_unlock(&shid->power_lock);
+
+	dev_dbg(dev, "%s: %s -> %s\n", __func__,
+			spi_hid_power_mode_string(prev_state),
+			spi_hid_power_mode_string(shid->power_state));
+}
+
+static void spi_hid_refresh_device_work(struct work_struct *work)
+{
+	struct spi_hid *shid =
+		container_of(work, struct spi_hid, refresh_device_work);
+	struct device *dev = &shid->spi->dev;
+	struct hid_device *hid;
+	int ret;
+	u32 new_crc32;
+
+	trace_spi_hid_refresh_device_work(shid);
+
+	mutex_lock(&shid->power_lock);
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF) {
+		dev_err(dev, "%s: Powered off, returning", __func__);
+		goto out2;
+	}
+
+	mutex_lock(&shid->output_lock);
+	ret = spi_hid_report_descriptor_request(shid);
+	mutex_unlock(&shid->output_lock);
+	if (ret < 0) {
+		dev_err(dev,
+			"Refresh: failed report descriptor request, error %d",
+			ret);
+		goto out2;
+	}
+
+	new_crc32 = crc32_le(0, (unsigned char const *)shid->response.content,
+								(size_t)ret);
+	if (new_crc32 == shid->report_descriptor_crc32)
+		goto out1;
+
+	shid->report_descriptor_crc32 = new_crc32;
+	shid->refresh_in_progress = true;
+
+	hid = spi_hid_disconnect_hid(shid);
+	if (hid)
+		hid_destroy_device(hid);
+
+	ret = spi_hid_create_device(shid);
+	if (ret) {
+		dev_err(dev, "%s: Failed to create hid device\n", __func__);
+		goto out2;
+	}
+
+	shid->refresh_in_progress = false;
+
+out1:
+	if (completion_done(&shid->ready_done))
+		dev_err(&shid->spi->dev, "Nobody waiting for ready_done\n");
+	else
+		complete(&shid->ready_done);
+out2:
+	mutex_unlock(&shid->power_lock);
+}
+
+static int spi_hid_get_request(struct spi_hid *shid, u8 content_id)
+{
+	int ret;
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_GET_FEATURE,
+		.content_length = 0,
+		.content_id = content_id,
+		.content = NULL,
+	};
+
+	ret = spi_hid_sync_request(shid, &report);
+	if (ret) {
+		dev_err(dev,
+			"Expected get request response not received! Error %d\n",
+			ret);
+		schedule_work(&shid->error_work);
+	}
+
+	return ret;
+}
+
+static int spi_hid_set_request(struct spi_hid *shid,
+		u8 *arg_buf, u16 arg_len, u8 content_id)
+{
+	struct spi_hid_output_report report = {
+		.report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_SET_FEATURE,
+		.content_length = arg_len,
+		.content_id = content_id,
+		.content = arg_buf,
+	};
+
+	return spi_hid_sync_request(shid, &report);
+}
+
+static irqreturn_t spi_hid_dev_irq(int irq, void *_shid)
+{
+	struct spi_hid *shid = _shid;
+	struct device *dev = &shid->spi->dev;
+	struct spi_hid_input_header header;
+	int ret = 0;
+
+	trace_spi_hid_dev_irq(shid, irq);
+	trace_spi_hid_header_transfer(shid);
+
+	ret = spi_hid_input_sync(shid, shid->input.header,
+			sizeof(shid->input.header), true);
+	if (ret) {
+		dev_err(dev, "Failed to transfer header: %d\n", ret);
+		goto out;
+	}
+
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF) {
+		dev_warn(dev, "Device is off after header was received\n");
+		goto out;
+	}
+
+	trace_spi_hid_input_header_complete(shid,
+				shid->input_transfer[0].tx_buf,
+				shid->input_transfer[0].len,
+				shid->input_transfer[1].rx_buf,
+				shid->input_transfer[1].len,
+				shid->input_message.status);
+
+	if (shid->input_message.status < 0) {
+		dev_warn(dev, "Error reading header: %d\n",
+				shid->input_message.status);
+		shid->bus_error_count++;
+		shid->bus_last_error = shid->input_message.status;
+		schedule_work(&shid->error_work);
+		goto out;
+	}
+
+	spi_hid_populate_input_header(shid->input.header, &header);
+
+	ret = spi_hid_bus_validate_header(shid, &header);
+	if (ret) {
+		dev_err(dev, "Failed to validate header: %d\n", ret);
+		print_hex_dump(KERN_ERR, "spi_hid: header buffer: ",
+						DUMP_PREFIX_NONE, 16, 1,
+						shid->input.header,
+						sizeof(shid->input.header),
+						false);
+		shid->bus_error_count++;
+		shid->bus_last_error = ret;
+		goto out;
+	}
+
+	ret = spi_hid_input_sync(shid, shid->input.body, header.report_length,
+				false);
+	if (ret)
+		dev_err(dev, "Failed to transfer body: %d\n", ret);
+
+	if (shid->power_state == SPI_HID_POWER_MODE_OFF) {
+		dev_warn(dev, "Device is off after body was received\n");
+		goto out;
+	}
+
+	trace_spi_hid_input_body_complete(shid, shid->input_transfer[0].tx_buf,
+						shid->input_transfer[0].len,
+						shid->input_transfer[1].rx_buf,
+						shid->input_transfer[1].len,
+						shid->input_message.status);
+
+	if (shid->input_message.status < 0) {
+		dev_warn(dev, "Error reading body: %d\n",
+				shid->input_message.status);
+		shid->bus_error_count++;
+		shid->bus_last_error = shid->input_message.status;
+		schedule_work(&shid->error_work);
+		goto out;
+	}
+
+	spi_hid_process_input_report(shid, &shid->input);
+
+out:
+	return IRQ_HANDLED;
+}
+
+/* hid_ll_driver interface functions */
+
+static int spi_hid_ll_start(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+
+	if (shid->desc.max_input_length < HID_MIN_BUFFER_SIZE) {
+		dev_err(&shid->spi->dev,
+			"HID_MIN_BUFFER_SIZE > max_input_length (%d)\n",
+			shid->desc.max_input_length);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void spi_hid_ll_stop(struct hid_device *hid)
+{
+	hid->claimed = 0;
+}
+
+static int spi_hid_ll_open(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	u8 prev_state = shid->power_state;
+	int ret;
+
+	if (shid->refresh_in_progress)
+		return 0;
+
+	spi_hid_resume(shid);
+
+	dev_dbg(dev, "%s: %s -> %s\n", __func__,
+			spi_hid_power_mode_string(prev_state),
+			spi_hid_power_mode_string(shid->power_state));
+
+	reinit_completion(&shid->ready_done);
+	ret = wait_for_completion_interruptible_timeout(&shid->ready_done,
+			msecs_to_jiffies(1000));
+	if (ret == 0) {
+		dev_err(dev, "Handshake timed out\n");
+		return -EAGAIN;
+	} else {
+		dev_dbg(dev, "%s: ready\n", __func__);
+		shid->ready = true;
+		return 0;
+	}
+}
+
+static void spi_hid_ll_close(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	u8 prev_state = shid->power_state;
+
+	if (shid->refresh_in_progress)
+		return;
+
+	mutex_lock(&shid->power_lock);
+	spi_hid_suspend(shid);
+	mutex_unlock(&shid->power_lock);
+
+	shid->attempts = 0;
+
+	dev_dbg(dev, "%s: %s -> %s\n", __func__,
+			spi_hid_power_mode_string(prev_state),
+			spi_hid_power_mode_string(shid->power_state));
+}
+
+static int spi_hid_ll_power(struct hid_device *hid, int level)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	int ret = 0;
+
+	mutex_lock(&shid->output_lock);
+	if (!shid->hid)
+		ret = -ENODEV;
+	mutex_unlock(&shid->output_lock);
+
+	return ret;
+}
+
+static int spi_hid_ll_parse(struct hid_device *hid)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int ret, len;
+
+	mutex_lock(&shid->output_lock);
+
+	len = spi_hid_report_descriptor_request(shid);
+	if (len < 0) {
+		dev_err(dev, "Report descriptor request failed, %d\n", len);
+		ret = len;
+		goto out;
+	}
+
+	/*
+	 * FIXME: below call returning 0 doesn't mean that the report descriptor
+	 * is good. We might be caching a crc32 of a corrupted r. d. or who
+	 * knows what the FW sent. Need to have a feedback loop about r. d.
+	 * being ok and only then cache it.
+	 */
+	ret = hid_parse_report(hid, (u8 *)shid->response.content, len);
+	if (ret)
+		dev_err(dev, "failed parsing report: %d\n", ret);
+	else
+		shid->report_descriptor_crc32 = crc32_le(0,
+				(unsigned char const *)shid->response.content,
+				len);
+
+out:
+	mutex_unlock(&shid->output_lock);
+
+	return ret;
+}
+
+static int spi_hid_ll_raw_request(struct hid_device *hid,
+		unsigned char reportnum, u8 *buf, size_t len,
+		unsigned char rtype, int reqtype)
+{
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int ret;
+
+	if (!shid->ready) {
+		dev_err(&shid->spi->dev, "%s called in unready state\n",
+								__func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&shid->output_lock);
+
+	switch (reqtype) {
+	case HID_REQ_SET_REPORT:
+		if (buf[0] != reportnum) {
+			dev_err(dev, "report id mismatch\n");
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = spi_hid_set_request(shid, &buf[1], len - 1,
+				reportnum);
+		if (ret) {
+			dev_err(dev, "failed to set report\n");
+			break;
+		}
+
+		ret = len;
+		break;
+	case HID_REQ_GET_REPORT:
+		ret = spi_hid_get_request(shid, reportnum);
+		if (ret) {
+			dev_err(dev, "failed to get report\n");
+			break;
+		}
+
+		ret = min_t(size_t, len,
+			shid->response.body[1] | (shid->response.body[2] << 8));
+		memcpy(buf, &shid->response.content, ret);
+		break;
+	default:
+		dev_err(dev, "invalid request type\n");
+		ret = -EIO;
+	}
+
+	mutex_unlock(&shid->output_lock);
+
+	return ret;
+}
+
+static int spi_hid_ll_output_report(struct hid_device *hid,
+		u8 *buf, size_t len)
+{
+	int ret;
+	struct spi_device *spi = hid->driver_data;
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	struct spi_hid_output_report report = {
+		.report_type = SPI_HID_OUTPUT_REPORT_TYPE_HID_OUTPUT_REPORT,
+		.content_length = len - 1,
+		.content_id = buf[0],
+		.content = &buf[1],
+	};
+
+	mutex_lock(&shid->output_lock);
+	if (!shid->ready) {
+		dev_err(dev, "%s called in unready state\n", __func__);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (shid->desc.no_output_report_ack)
+		ret = spi_hid_send_output_report(shid, &report);
+	else
+		ret = spi_hid_sync_request(shid, &report);
+
+	if (ret)
+		dev_err(dev, "failed to send output report\n");
+
+out:
+	mutex_unlock(&shid->output_lock);
+
+	if (ret > 0)
+		return -ret;
+
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static struct hid_ll_driver spi_hid_ll_driver = {
+	.start = spi_hid_ll_start,
+	.stop = spi_hid_ll_stop,
+	.open = spi_hid_ll_open,
+	.close = spi_hid_ll_close,
+	.power = spi_hid_ll_power,
+	.parse = spi_hid_ll_parse,
+	.output_report = spi_hid_ll_output_report,
+	.raw_request = spi_hid_ll_raw_request,
+};
+
+const struct of_device_id spi_hid_of_match[] = {
+	{ .compatible = "hid-over-spi" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, spi_hid_of_match);
+
+static ssize_t bus_error_count_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d (%d)\n",
+			shid->bus_error_count, shid->bus_last_error);
+}
+static DEVICE_ATTR_RO(bus_error_count);
+
+static ssize_t regulator_error_count_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d (%d)\n",
+			shid->regulator_error_count,
+			shid->regulator_last_error);
+}
+static DEVICE_ATTR_RO(regulator_error_count);
+
+static ssize_t device_initiated_reset_count_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct spi_hid *shid = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", shid->dir_count);
+}
+static DEVICE_ATTR_RO(device_initiated_reset_count);
+
+static const struct attribute *const spi_hid_attributes[] = {
+	&dev_attr_bus_error_count.attr,
+	&dev_attr_regulator_error_count.attr,
+	&dev_attr_device_initiated_reset_count.attr,
+	NULL	/* Terminator */
+};
+
+static int spi_hid_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct spi_hid *shid;
+	unsigned long irqflags;
+	int ret;
+
+	if (spi->irq <= 0) {
+		dev_err(dev, "Missing IRQ\n");
+		ret = spi->irq ?: -EINVAL;
+		goto err0;
+	}
+
+	shid = devm_kzalloc(dev, sizeof(struct spi_hid), GFP_KERNEL);
+	if (!shid) {
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	shid->spi = spi;
+	shid->power_state = SPI_HID_POWER_MODE_ON;
+	spi_set_drvdata(spi, shid);
+
+	ret = sysfs_create_files(&dev->kobj, spi_hid_attributes);
+	if (ret) {
+		dev_err(dev, "Unable to create sysfs attributes\n");
+		goto err0;
+	}
+
+	ret = spi_hid_of_populate_config(&shid->conf, dev);
+	if (ret) {
+		dev_err(dev, "%s: unable to populate config data\n", __func__);
+		goto err1;
+	}
+
+	/* Using now populated conf let's pre-calculate the read approvals */
+	spi_hid_populate_read_approvals(&shid->conf, shid->read_approval_header,
+						shid->read_approval_body);
+
+	mutex_init(&shid->output_lock);
+	mutex_init(&shid->power_lock);
+	init_completion(&shid->output_done);
+	init_completion(&shid->ready_done);
+
+	INIT_WORK(&shid->reset_response_work, spi_hid_reset_response_work);
+	INIT_WORK(&shid->create_device_work, spi_hid_create_device_work);
+	INIT_WORK(&shid->refresh_device_work, spi_hid_refresh_device_work);
+	INIT_WORK(&shid->error_work, spi_hid_error_work);
+
+	/*
+	 * At the end of probe we initialize the device:
+	 *   0) Default pinctrl in DT: assert reset, bias the interrupt line
+	 *   1) sleep minimal reset delay
+	 *   2) request IRQ
+	 *   3) power up the device
+	 *   4) deassert reset (high)
+	 * After this we expect an IRQ with a reset response.
+	 */
+
+	spi_hid_of_sleep_minimal_reset_delay(&shid->conf);
+
+	irqflags = irq_get_trigger_type(spi->irq) | IRQF_ONESHOT;
+	ret = devm_request_threaded_irq(dev, spi->irq, NULL, spi_hid_dev_irq,
+			irqflags, dev_name(&spi->dev), shid);
+	if (ret) {
+		dev_err(dev, "%s: unable to request threaded IRQ\n", __func__);
+		goto err1;
+	}
+	shid->irq_enabled = true;
+
+	ret = spi_hid_of_power_up(&shid->conf);
+	if (ret) {
+		dev_err(dev, "%s: could not power up\n", __func__);
+		shid->regulator_error_count++;
+		shid->regulator_last_error = ret;
+		goto err1;
+	}
+
+	spi_hid_of_deassert_reset(&shid->conf);
+
+	dev_dbg(dev, "%s: d3 -> %s\n", __func__,
+			spi_hid_power_mode_string(shid->power_state));
+
+	return 0;
+
+err1:
+	sysfs_remove_files(&dev->kobj, spi_hid_attributes);
+
+err0:
+	return ret;
+}
+
+static int spi_hid_remove(struct spi_device *spi)
+{
+	struct spi_hid *shid = spi_get_drvdata(spi);
+	struct device *dev = &spi->dev;
+	int ret;
+
+	spi_hid_of_assert_reset(&shid->conf);
+	ret = spi_hid_of_power_down(&shid->conf);
+	if (ret) {
+		dev_err(dev, "failed to disable regulator\n");
+		shid->regulator_error_count++;
+		shid->regulator_last_error = ret;
+	}
+	sysfs_remove_files(&dev->kobj, spi_hid_attributes);
+	spi_hid_stop_hid(shid);
+
+	return 0;
+}
+
+static const struct spi_device_id spi_hid_id_table[] = {
+	{ "hid", 0 },
+	{ "hid-over-spi", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, spi_hid_id_table);
+
+static struct spi_driver spi_hid_driver = {
+	.driver = {
+		.name	= "spi_hid",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(spi_hid_of_match),
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.probe		= spi_hid_probe,
+	.remove		= spi_hid_remove,
+	.id_table	= spi_hid_id_table,
+};
+
+module_spi_driver(spi_hid_driver);
+
+MODULE_DESCRIPTION("HID over SPI transport driver");
+MODULE_AUTHOR("Dmitry Antipov <dmanti@microsoft.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/spi-hid/spi-hid-core.h b/drivers/hid/spi-hid/spi-hid-core.h
new file mode 100644
index 000000000000..45cf3fd2b369
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-core.h
@@ -0,0 +1,188 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ */
+
+#ifndef SPI_HID_CORE_H
+#define SPI_HID_CORE_H
+
+#include <linux/completion.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "spi-hid-of.h"
+
+/* Protocol constants */
+#define SPI_HID_READ_APPROVAL_CONSTANT		0xff
+#define SPI_HID_INPUT_HEADER_SYNC_BYTE		0x5a
+#define SPI_HID_INPUT_HEADER_VERSION		0x03
+#define SPI_HID_SUPPORTED_VERSION		0x0300
+
+/* Protocol message size constants */
+#define SPI_HID_READ_APPROVAL_LEN		5
+#define SPI_HID_INPUT_HEADER_LEN		4
+#define SPI_HID_INPUT_BODY_LEN			4
+#define SPI_HID_OUTPUT_HEADER_LEN		8
+#define SPI_HID_DEVICE_DESCRIPTOR_LENGTH	24
+
+/* Protocol message type constants */
+#define SPI_HID_INPUT_REPORT_TYPE_DATA				0x01
+#define SPI_HID_INPUT_REPORT_TYPE_RESET_RESP			0x03
+#define SPI_HID_INPUT_REPORT_TYPE_COMMAND_RESP			0x04
+#define SPI_HID_INPUT_REPORT_TYPE_GET_FEATURE_RESP		0x05
+#define SPI_HID_INPUT_REPORT_TYPE_DEVICE_DESC			0x07
+#define SPI_HID_INPUT_REPORT_TYPE_REPORT_DESC			0x08
+#define SPI_HID_INPUT_REPORT_TYPE_SET_FEATURE_RESP		0x09
+#define SPI_HID_INPUT_REPORT_TYPE_SET_OUTPUT_REPORT_RESP	0x0a
+#define SPI_HID_INPUT_REPORT_TYPE_GET_INPUT_REPORT_RESP		0x0b
+
+#define SPI_HID_OUTPUT_REPORT_TYPE_DEVICE_DESC_REQUEST	0x01
+#define SPI_HID_OUTPUT_REPORT_TYPE_REPORT_DESC_REQUEST	0x02
+#define SPI_HID_OUTPUT_REPORT_TYPE_HID_SET_FEATURE	0x03
+#define SPI_HID_OUTPUT_REPORT_TYPE_HID_GET_FEATURE	0x04
+#define SPI_HID_OUTPUT_REPORT_TYPE_HID_OUTPUT_REPORT	0x05
+#define SPI_HID_OUTPUT_REPORT_TYPE_INPUT_REPORT_REQUEST	0x06
+#define SPI_HID_OUTPUT_REPORT_TYPE_COMMAND		0x07
+
+#define SPI_HID_OUTPUT_REPORT_CONTENT_ID_DESC_REQUEST	0x00
+
+/* Power mode constants */
+#define SPI_HID_POWER_MODE_ON			0x01
+#define SPI_HID_POWER_MODE_SLEEP		0x02
+#define SPI_HID_POWER_MODE_OFF			0x03
+#define SPI_HID_POWER_MODE_WAKING_SLEEP		0x04
+
+/* Raw input buffer with data from the bus */
+struct spi_hid_input_buf {
+	u8 header[SPI_HID_INPUT_HEADER_LEN];
+	u8 body[SPI_HID_INPUT_BODY_LEN];
+	u8 content[SZ_8K];
+};
+
+/* Processed data from  input report header */
+struct spi_hid_input_header {
+	u8 version;
+	u16 report_length;
+	u8 last_fragment_flag;
+	u8 sync_const;
+};
+
+/* Processed data from input report body, excluding the content */
+struct spi_hid_input_body {
+	u8 report_type;
+	u16 content_length;
+	u8 content_id;
+};
+
+/* Processed data from an input report */
+struct spi_hid_input_report {
+	u8 report_type;
+	u16 content_length;
+	u8 content_id;
+	u8 *content;
+};
+
+/* Raw output report buffer to be put on the bus */
+struct spi_hid_output_buf {
+	u8 header[SPI_HID_OUTPUT_HEADER_LEN];
+	u8 content[SZ_8K];
+};
+
+/* Data necessary to send an output report */
+struct spi_hid_output_report {
+	u8 report_type;
+	u16 content_length;
+	u8 content_id;
+	u8 *content;
+};
+
+/* Raw content in device descriptor */
+struct spi_hid_device_desc_raw {
+	__le16 wDeviceDescLength;
+	__le16 bcdVersion;
+	__le16 wReportDescLength;
+	__le16 wMaxInputLength;
+	__le16 wMaxOutputLength;
+	__le16 wMaxFragmentLength;
+	__le16 wVendorID;
+	__le16 wProductID;
+	__le16 wVersionID;
+	__le16 wFlags;
+	u8 reserved[4];
+} __packed;
+
+/* Processed data from a device descriptor */
+struct spi_hid_device_descriptor {
+	u16 hid_version;
+	u16 report_descriptor_length;
+	u16 max_input_length;
+	u16 max_output_length;
+	u16 max_fragment_length;
+	u16 vendor_id;
+	u16 product_id;
+	u16 version_id;
+	u8 no_output_report_ack;
+};
+
+/* Driver context */
+struct spi_hid {
+	struct spi_device	*spi;
+	struct hid_device	*hid;
+
+	struct spi_transfer	input_transfer[2];
+	struct spi_transfer	output_transfer;
+	struct spi_message	input_message;
+	struct spi_message	output_message;
+
+	struct spi_hid_of_config conf;
+	struct spi_hid_device_descriptor desc;
+	struct spi_hid_output_buf output;
+	struct spi_hid_input_buf input;
+	struct spi_hid_input_buf response;
+
+	u32 input_transfer_pending;
+
+	u8 power_state;
+
+	u8 attempts;
+
+	/*
+	 * ready flag indicates that the FW is ready to accept commands and
+	 * requests. The FW becomes ready after sending the report descriptor.
+	 */
+	bool ready;
+	/*
+	 * refresh_in_progress is set to true while the refresh_device worker
+	 * thread is destroying and recreating the hidraw device. When this flag
+	 * is set to true, the ll_close and ll_open functions will not cause
+	 * power state changes.
+	 */
+	bool refresh_in_progress;
+
+	bool irq_enabled;
+
+	struct work_struct reset_response_work;
+	struct work_struct create_device_work;
+	struct work_struct refresh_device_work;
+	struct work_struct error_work;
+
+	struct mutex output_lock;
+	struct mutex power_lock;
+	struct completion output_done;
+	struct completion ready_done;
+
+	u8 read_approval_header[SPI_HID_READ_APPROVAL_LEN];
+	u8 read_approval_body[SPI_HID_READ_APPROVAL_LEN];
+
+	u32 report_descriptor_crc32;
+
+	u32 regulator_error_count;
+	int regulator_last_error;
+	u32 bus_error_count;
+	int bus_last_error;
+	u32 dir_count;
+};
+
+#endif
diff --git a/drivers/hid/spi-hid/spi-hid-of.c b/drivers/hid/spi-hid/spi-hid-of.c
new file mode 100644
index 000000000000..d8d1d134cf29
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-of.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID over SPI protocol, Open Firmware related code
+ *
+ * Copyright (c) 2021 Microsoft Corporation
+ *
+ * This code was forked out of the HID over SPI core code, which is partially
+ * based on "HID over I2C protocol implementation:
+ *
+ * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ * Copyright (c) 2012 Red Hat, Inc
+ *
+ * which in turn is partially based on "USB HID support for Linux":
+ *
+ * Copyright (c) 1999 Andreas Gal
+ * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ * Copyright (c) 2007-2008 Oliver Neukum
+ * Copyright (c) 2006-2010 Jiri Kosina
+ */
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+
+#include "spi-hid-core.h"
+
+int spi_hid_of_populate_config(struct spi_hid_of_config *conf,
+				struct device *dev)
+{
+	int ret;
+	u32 val;
+
+	ret = device_property_read_u32(dev, "input-report-header-address",
+									&val);
+	if (ret) {
+		dev_err(dev, "Input report header address not provided\n");
+		return -ENODEV;
+	}
+	conf->input_report_header_address = val;
+
+	ret = device_property_read_u32(dev, "input-report-body-address", &val);
+	if (ret) {
+		dev_err(dev, "Input report body address not provided\n");
+		return -ENODEV;
+	}
+	conf->input_report_body_address = val;
+
+	ret = device_property_read_u32(dev, "output-report-address", &val);
+	if (ret) {
+		dev_err(dev, "Output report address not provided\n");
+		return -ENODEV;
+	}
+	conf->output_report_address = val;
+
+	ret = device_property_read_u32(dev, "read-opcode", &val);
+	if (ret) {
+		dev_err(dev, "Read opcode not provided\n");
+		return -ENODEV;
+	}
+	conf->read_opcode = val;
+
+	ret = device_property_read_u32(dev, "write-opcode", &val);
+	if (ret) {
+		dev_err(dev, "Write opcode not provided\n");
+		return -ENODEV;
+	}
+	conf->write_opcode = val;
+
+	ret = device_property_read_u32(dev, "post-power-on-delay-ms", &val);
+	if (ret) {
+		dev_err(dev, "post-power-on-delay-ms not provided, using 10\n");
+		val = 10;
+	}
+	conf->post_power_on_delay_ms = val;
+
+	ret = device_property_read_u32(dev, "minimal-reset-delay-ms", &val);
+	if (ret) {
+		dev_err(dev, "minimal-reset-delay-ms not provided, using 100\n");
+		val = 100;
+	}
+	conf->minimal_reset_delay_ms = val;
+
+	/* FIXME: not reading hid-over-spi-flags, multi-SPI not supported */
+
+	conf->supply = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(conf->supply)) {
+		if (PTR_ERR(conf->supply) != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get regulator: %ld\n",
+					PTR_ERR(conf->supply));
+		return PTR_ERR(conf->supply);
+	}
+
+	conf->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(conf->reset_gpio)) {
+		dev_err(dev, "%s: error getting reset GPIO\n", __func__);
+		return PTR_ERR(conf->reset_gpio);
+	}
+
+	return 0;
+}
+
+int spi_hid_of_power_down(struct spi_hid_of_config *conf)
+{
+	if (regulator_is_enabled(conf->supply) == 0)
+		return 0;
+
+	return regulator_disable(conf->supply);
+}
+
+int spi_hid_of_power_up(struct spi_hid_of_config *conf)
+{
+	int ret;
+
+	if (regulator_is_enabled(conf->supply) > 0)
+		return 0;
+
+	ret = regulator_enable(conf->supply);
+
+	usleep_range(1000 * conf->post_power_on_delay_ms,
+			1000 * (conf->post_power_on_delay_ms + 1));
+
+	return ret;
+}
+
+void spi_hid_of_assert_reset(struct spi_hid_of_config *conf)
+{
+	gpiod_set_value(conf->reset_gpio, 1);
+}
+
+void spi_hid_of_deassert_reset(struct spi_hid_of_config *conf)
+{
+	gpiod_set_value(conf->reset_gpio, 0);
+}
+
+void spi_hid_of_sleep_minimal_reset_delay(struct spi_hid_of_config *conf)
+{
+	usleep_range(1000 * conf->minimal_reset_delay_ms,
+			1000 * (conf->minimal_reset_delay_ms + 1));
+}
diff --git a/drivers/hid/spi-hid/spi-hid-of.h b/drivers/hid/spi-hid/spi-hid-of.h
new file mode 100644
index 000000000000..48d9dfe44e95
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid-of.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ */
+
+#ifndef SPI_HID_OF_H
+#define SPI_HID_OF_H
+
+/* Config structure is filled with data from Device Tree */
+struct spi_hid_of_config {
+	u32 input_report_header_address;
+	u32 input_report_body_address;
+	u32 output_report_address;
+	u8 read_opcode;
+	u8 write_opcode;
+	u32 post_power_on_delay_ms;
+	u32 minimal_reset_delay_ms;
+	struct gpio_desc *reset_gpio;
+	struct regulator *supply;
+};
+
+int spi_hid_of_populate_config(struct spi_hid_of_config *conf,
+				struct device *dev);
+int spi_hid_of_power_down(struct spi_hid_of_config *conf);
+int spi_hid_of_power_up(struct spi_hid_of_config *conf);
+void spi_hid_of_assert_reset(struct spi_hid_of_config *conf);
+void spi_hid_of_deassert_reset(struct spi_hid_of_config *conf);
+void spi_hid_of_sleep_minimal_reset_delay(struct spi_hid_of_config *conf);
+
+#endif
diff --git a/drivers/hid/spi-hid/spi-hid_trace.h b/drivers/hid/spi-hid/spi-hid_trace.h
new file mode 100644
index 000000000000..23732ba493a0
--- /dev/null
+++ b/drivers/hid/spi-hid/spi-hid_trace.h
@@ -0,0 +1,194 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM spi_hid
+
+#if !defined(_SPI_HID_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _SPI_HID_TRACE_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+#include "spi-hid-core.h"
+
+DECLARE_EVENT_CLASS(spi_hid_transfer,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, len)
+		__field(int, ret)
+		__dynamic_array(u8, rx_buf, rx_len)
+		__dynamic_array(u8, tx_buf, tx_len)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->len = rx_len + tx_len;
+		__entry->ret = ret;
+
+		memcpy(__get_dynamic_array(tx_buf), tx_buf, tx_len);
+		memcpy(__get_dynamic_array(rx_buf), rx_buf, rx_len);
+	),
+
+	TP_printk("spi%d.%d: len=%d tx=[%*phD] rx=[%*phD] --> %d",
+		__entry->bus_num, __entry->chip_select, __entry->len,
+		__get_dynamic_array_len(tx_buf), __get_dynamic_array(tx_buf),
+		__get_dynamic_array_len(rx_buf), __get_dynamic_array(rx_buf),
+		__entry->ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_sync,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_header_complete,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_input_body_complete,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_output_begin,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret)
+);
+
+DEFINE_EVENT(spi_hid_transfer, spi_hid_output_end,
+	TP_PROTO(struct spi_hid *shid, const void *tx_buf, int tx_len,
+			const void *rx_buf, u16 rx_len, int ret),
+	TP_ARGS(shid, tx_buf, tx_len, rx_buf, rx_len, ret)
+);
+
+DECLARE_EVENT_CLASS(spi_hid_irq,
+	TP_PROTO(struct spi_hid *shid, int irq),
+
+	TP_ARGS(shid, irq),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, irq)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->irq = irq;
+	),
+
+	TP_printk("spi%d.%d: IRQ %d",
+		__entry->bus_num, __entry->chip_select, __entry->irq)
+);
+
+DEFINE_EVENT(spi_hid_irq, spi_hid_dev_irq,
+	TP_PROTO(struct spi_hid *shid, int irq),
+	TP_ARGS(shid, irq)
+);
+
+DECLARE_EVENT_CLASS(spi_hid,
+	TP_PROTO(struct spi_hid *shid),
+
+	TP_ARGS(shid),
+
+	TP_STRUCT__entry(
+		__field(int, bus_num)
+		__field(int, chip_select)
+		__field(int, power_state)
+		__field(bool, ready)
+
+		__field(int, vendor_id)
+		__field(int, product_id)
+		__field(int, max_input_length)
+		__field(int, max_output_length)
+		__field(u16, hid_version)
+		__field(u16, report_descriptor_length)
+		__field(u16, version_id)
+	),
+
+	TP_fast_assign(
+		__entry->bus_num = shid->spi->controller->bus_num;
+		__entry->chip_select = shid->spi->chip_select;
+		__entry->power_state = shid->power_state;
+		__entry->ready = shid->ready;
+
+		__entry->vendor_id = shid->desc.vendor_id;
+		__entry->product_id = shid->desc.product_id;
+		__entry->max_input_length = shid->desc.max_input_length;
+		__entry->max_output_length = shid->desc.max_output_length;
+		__entry->hid_version = shid->desc.hid_version;
+		__entry->report_descriptor_length =
+					shid->desc.report_descriptor_length;
+		__entry->version_id = shid->desc.version_id;
+	),
+
+	TP_printk("spi%d.%d: (%04x:%04x v%d) HID v%d.%d state i:%d p:%d len i:%d o:%d r:%d flags %c",
+		__entry->bus_num, __entry->chip_select, __entry->vendor_id,
+		__entry->product_id, __entry->version_id,
+		__entry->hid_version >> 8, __entry->hid_version & 0xff,
+		__entry->power_state,	__entry->max_input_length,
+		__entry->max_output_length, __entry->report_descriptor_length,
+		__entry->ready ? 'R' : 'r')
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_header_transfer,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_process_input_report,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_input_report_handler,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_reset_response_work,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_create_device_work,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_refresh_device_work,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_response_handler,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+DEFINE_EVENT(spi_hid, spi_hid_error_work,
+	TP_PROTO(struct spi_hid *shid),
+	TP_ARGS(shid)
+);
+
+#endif /* _SPI_HID_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE spi-hid_trace
+#include <trace/define_trace.h>
diff --git a/drivers/hid/spi-hid/trace.c b/drivers/hid/spi-hid/trace.c
new file mode 100644
index 000000000000..6cd686c9493e
--- /dev/null
+++ b/drivers/hid/spi-hid/trace.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Microsoft Corporation
+ *
+ * Author: Felipe Balbi <felipe.balbi@microsoft.com>
+ */
+
+#define CREATE_TRACE_POINTS
+#include "spi-hid_trace.h"
-- 
2.25.1

[PATCH v4 6/6] Defconfig: add CONFIG_SPI_HID=m

[Dmitry Antipov]

From: Dmitry Antipov <dmanti@microsoft.com>

This enables building drivers/hid/spi-hid as module.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index f2e2b9bdd702..25249a4b0c8a 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -805,6 +805,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m
 CONFIG_HID_MULTITOUCH=m
 CONFIG_I2C_HID_ACPI=m
 CONFIG_I2C_HID_OF=m
+CONFIG_SPI_HID=m
 CONFIG_USB_CONN_GPIO=m
 CONFIG_USB=y
 CONFIG_USB_OTG=y
-- 
2.25.1

Re: [PATCH v4 3/6] Documentation: DT bindings for Microsoft G6 Touch Digitizer

[Rob Herring]

On Thu, 24 Feb 2022 16:59:33 -0800, Dmitry Antipov wrote:
> From: Dmitry Antipov <dmanti@microsoft.com>
> 
> Documentation describes the required and optional properties for
> implementing Device Tree for a Microsoft G6 Touch Digitizer that
> supports HID over SPI Protocol 1.0 specification.
> 
> Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
> ---
>  .../input/microsoft,g6-touch-digitizer.yaml   | 105 ++++++++++++++++++
>  1 file changed, 105 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
./Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml:22:9: [warning] wrong indentation: expected 10 but found 8 (indentation)

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dts:23.11-21: Warning (reg_format): /example-0/spi-hid-dev0:reg: property has invalid length (4 bytes) (#address-cells == 1, #size-cells == 1)
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dts:21.22-37.11: Warning (unit_address_vs_reg): /example-0/spi-hid-dev0: node has a reg or ranges property, but no unit name
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dt.yaml: Warning (pci_device_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dt.yaml: Warning (pci_device_bus_num): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dt.yaml: Warning (simple_bus_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dt.yaml: Warning (i2c_bus_reg): Failed prerequisite 'reg_format'
Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.example.dt.yaml: Warning (spi_bus_reg): Failed prerequisite 'reg_format'

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/1597405

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit.

Re: [PATCH v4 3/6] Documentation: DT bindings for Microsoft G6 Touch Digitizer

[Rob Herring]

On Thu, Feb 24, 2022 at 04:59:33PM -0800, Dmitry Antipov wrote:
> From: Dmitry Antipov <dmanti@microsoft.com>

Please follow the conventions of the subsystem for the subject:

dt-bindings: input: ...

> 
> Documentation describes the required and optional properties for
> implementing Device Tree for a Microsoft G6 Touch Digitizer that
> supports HID over SPI Protocol 1.0 specification.
> 
> Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
> ---
>  .../input/microsoft,g6-touch-digitizer.yaml   | 105 ++++++++++++++++++
>  1 file changed, 105 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
> new file mode 100644
> index 000000000000..e516717527e9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
> @@ -0,0 +1,105 @@
> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/microsoft,g6-touch-digitizer.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microsoft G6 Touch Digitizer
> +
> +maintainers:
> +  - Dmitry Antipov <dmanti@microsoft.com>
> +
> +description: |
> +  Microsoft G6 touch digitizer is a HID over SPI device supporting HID Over SPI
> +  Protocol Specification 1.0, available at
> +  https://www.microsoft.com/en-us/download/details.aspx?id=103325.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: microsoft,g6-touch-digitizer
> +      - items:
> +        - const: microsoft,g6-touch-digitizer
> +        - const: hid-over-spi

Why are both cases needed?

Assuming you keep the 2nd case, you will need a custom 'select' to avoid 
applying this schema to another binding using 'hid-over-spi':

select:
  properties:
    compatible:
      contains:
	const: microsoft,g6-touch-digitizer

  required:
    - compatible


> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  reset-gpios:
> +    maxItems: 1
> +    description:
> +      GPIO specifier for the digitizer's reset pin (active low). The line must
> +      be flagged with GPIO_ACTIVE_LOW.
> +
> +  vdd-supply:
> +    description:
> +      Regulator for the VDD supply voltage.
> +
> +  input-report-header-address:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      This property and the rest are described in HID Over SPI Protocol Spec 1.0

Each property needs a description and a more specific spec location.

No constraints on the values? 0 - 2^32 is valid?

> +
> +  input-report-body-address:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  output-report-address:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  read-opcode:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  write-opcode:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  hid-over-spi-flags:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +

> +  post-power-on-delay-ms:
> +    description:
> +      Optional time in ms required by the device after enabling its regulators
> +      or powering it on, before it is ready for communication.
> +
> +  minimal-reset-delay-ms:
> +    description:
> +      Optional minimum amount of time in ms that device needs to be in reset
> +      state for the reset to take effect.

These should be implied by the compatible string.

> +
> +required:
> +  - compatible
> +  - interrupts
> +  - reset-gpios

It's not allowed to have reset under h/w control?

> +  - vdd-supply
> +  - input-report-header-address
> +  - input-report-body-address
> +  - output-report-address
> +  - read-opcode
> +  - write-opcode
> +  - hid-over-spi-flags
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/gpio/gpio.h>
> +    spi-hid-dev0 {

hid@0

And you'll need to define a spi bus.

> +      compatible = "microsoft,g6-touch-digitizer", "hid-over-spi";
> +      reg = <0>;
> +      interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
> +      reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
> +      vdd-supply = <&pm8350c_l3>;
> +      pinctrl-names = "default";
> +      pinctrl-0 = <&ts_d6_reset_assert &ts_d6_int_bias>;
> +      input-report-header-address = <0x1000>;
> +      input-report-body-address = <0x1004>;
> +      output-report-address = <0x2000>;
> +      read-opcode = <0x0b>;
> +      write-opcode = <0x02>;
> +      hid-over-spi-flags = <0x00>;
> +      post-power-on-delay-ms = <5>;
> +      minimal-reset-delay-ms = <5>;
> +    };
> -- 
> 2.25.1
> 
> 

Re: [PATCH v4 3/6] Documentation: DT bindings for Microsoft G6 Touch Digitizer

[Dmitry Antipov]

On Fri, Feb 25, 2022 at 06:59AM, Rob Herring wrote:
> 
> On Thu, Feb 24, 2022 at 04:59:33PM -0800, Dmitry Antipov wrote:
> > From: Dmitry Antipov <dmanti@microsoft.com>
> 
> Please follow the conventions of the subsystem for the subject:
> 
> dt-bindings: input: ...

Will do, thank you.

> 
> >
> > Documentation describes the required and optional properties for 
> > implementing Device Tree for a Microsoft G6 Touch Digitizer that 
> > supports HID over SPI Protocol 1.0 specification.
> >
> > Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
> > ---
> >  .../input/microsoft,g6-touch-digitizer.yaml   | 105 ++++++++++++++++++
> >  1 file changed, 105 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer
> > .y
> > aml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitiz
> > er
> > .yaml
> > b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitiz
> > er
> > .yaml
> > new file mode 100644
> > index 000000000000..e516717527e9
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/input/microsoft,g6-touch-dig
> > +++ it
> > +++ izer.yaml
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - const: microsoft,g6-touch-digitizer
> > +      - items:
> > +        - const: microsoft,g6-touch-digitizer
> > +        - const: hid-over-spi
> 
> Why are both cases needed?
> 
> Assuming you keep the 2nd case, you will need a custom 'select' to 
> avoid applying this schema to another binding using 'hid-over-spi':
> 
> select:
>   properties:
>     compatible:
>       contains:
> 	const: microsoft,g6-touch-digitizer
> 
>   required:
>     - compatible
> 

We decided to make the driver compatible with "microsoft,g6-touch-digitizer" as
well as "hid-over-spi", so the next revision of the patch will list
"microsoft,g6-touch-digitizer" as the only compatible value.

> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  reset-gpios:
> > +    maxItems: 1
> > +    description:
> > +      GPIO specifier for the digitizer's reset pin (active low). The line must
> > +      be flagged with GPIO_ACTIVE_LOW.
> > +
> > +  vdd-supply:
> > +    description:
> > +      Regulator for the VDD supply voltage.
> > +
> > +  input-report-header-address:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      This property and the rest are described in HID Over SPI 
> > + Protocol Spec 1.0
> 
> Each property needs a description and a more specific spec location.
> 
> No constraints on the values? 0 - 2^32 is valid?
> 

Thank you. Will provide description for each property and will specify the bit
length of each address if outlined by the spec.

> > +
> > +  input-report-body-address:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  output-report-address:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  read-opcode:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  write-opcode:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  hid-over-spi-flags:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> 
> > +  post-power-on-delay-ms:
> > +    description:
> > +      Optional time in ms required by the device after enabling its regulators
> > +      or powering it on, before it is ready for communication.
> > +
> > +  minimal-reset-delay-ms:
> > +    description:
> > +      Optional minimum amount of time in ms that device needs to be 
> > + in
> reset
> > +      state for the reset to take effect.
> 
> These should be implied by the compatible string.

If I'm understanding you correctly here, you are asking for the driver to have
the heuristics to apply specific delays based on which compatible string is
published in the device tree. However, the same touch digitizer but on different
boards may have different delay requirements based on the voltage regulator used
or line capacitance. Therefore, I would argue it is better to have this delay
information provided by the device tree.

> 
> > +
> > +required:
> > +  - compatible
> > +  - interrupts
> > +  - reset-gpios
> 
> It's not allowed to have reset under h/w control?

No, the spec requires a discrete reset line.

> 
> > +  - vdd-supply
> > +  - input-report-header-address
> > +  - input-report-body-address
> > +  - output-report-address
> > +  - read-opcode
> > +  - write-opcode
> > +  - hid-over-spi-flags
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #include <dt-bindings/gpio/gpio.h>
> > +    spi-hid-dev0 {
> 
> hid@0
> 
> And you'll need to define a spi bus.

Thank you, will address in the next patch.

> 
> > +      compatible = "microsoft,g6-touch-digitizer", "hid-over-spi";
> > +      reg = <0>;
> > +      interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
> > +      reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
> > +      vdd-supply = <&pm8350c_l3>;
> > +      pinctrl-names = "default";
> > +      pinctrl-0 = <&ts_d6_reset_assert &ts_d6_int_bias>;
> > +      input-report-header-address = <0x1000>;
> > +      input-report-body-address = <0x1004>;
> > +      output-report-address = <0x2000>;
> > +      read-opcode = <0x0b>;
> > +      write-opcode = <0x02>;
> > +      hid-over-spi-flags = <0x00>;
> > +      post-power-on-delay-ms = <5>;
> > +      minimal-reset-delay-ms = <5>;
> > +    };
> > --
> > 2.25.1
> >
> >