linux-surface/patches/5.8/0003-ipts.patch

From 1fb79b576315c036f08e778546e71212230d9ddc Mon Sep 17 00:00:00 2001
From: Dorian Stoll <dorian.stoll@tmsp.io>
Date: Fri, 25 Sep 2020 18:06:05 +0200
Subject: [PATCH] mei: Remove client devices before shutting down

Patchset: ipts
---
 drivers/misc/mei/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index bcee77768b91..21ed765003e1 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -302,10 +302,10 @@ void mei_stop(struct mei_device *dev)
 {
 	dev_dbg(dev->dev, "stopping the device.\n");
 
+	mei_cl_bus_remove_devices(dev);
 	mutex_lock(&dev->device_lock);
 	mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
 	mutex_unlock(&dev->device_lock);
-	mei_cl_bus_remove_devices(dev);
 
 	mei_cancel_work(dev);
 
-- 
2.28.0

From b9b4c4f84f5111e3213225be406e43cc11623dbc Mon Sep 17 00:00:00 2001
From: Dorian Stoll <dorian.stoll@tmsp.io>
Date: Thu, 30 Jul 2020 13:21:53 +0200
Subject: [PATCH] misc: mei: Add missing IPTS device IDs

Patchset: ipts
---
 drivers/misc/mei/hw-me-regs.h | 3 +++
 drivers/misc/mei/pci-me.c     | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/misc/mei/hw-me-regs.h b/drivers/misc/mei/hw-me-regs.h
index 7becfc768bbc..0824ef27b08b 100644
--- a/drivers/misc/mei/hw-me-regs.h
+++ b/drivers/misc/mei/hw-me-regs.h
@@ -59,6 +59,7 @@
 
 #define MEI_DEV_ID_SPT        0x9D3A  /* Sunrise Point */
 #define MEI_DEV_ID_SPT_2      0x9D3B  /* Sunrise Point 2 */
+#define MEI_DEV_ID_SPT_3      0x9D3E  /* Sunrise Point 3 (iTouch) */
 #define MEI_DEV_ID_SPT_H      0xA13A  /* Sunrise Point H */
 #define MEI_DEV_ID_SPT_H_2    0xA13B  /* Sunrise Point H 2 */
 
@@ -73,6 +74,7 @@
 
 #define MEI_DEV_ID_KBP        0xA2BA  /* Kaby Point */
 #define MEI_DEV_ID_KBP_2      0xA2BB  /* Kaby Point 2 */
+#define MEI_DEV_ID_KBP_3      0xA2BE  /* Kaby Point 3 (iTouch) */
 
 #define MEI_DEV_ID_CNP_LP     0x9DE0  /* Cannon Point LP */
 #define MEI_DEV_ID_CNP_LP_3   0x9DE4  /* Cannon Point LP 3 (iTouch) */
@@ -90,6 +92,7 @@
 #define MEI_DEV_ID_CDF        0x18D3  /* Cedar Fork */
 
 #define MEI_DEV_ID_ICP_LP     0x34E0  /* Ice Lake Point LP */
+#define MEI_DEV_ID_ICP_LP_3   0x34E4  /* Ice Lake Point LP 3 (iTouch) */
 
 #define MEI_DEV_ID_JSP_N      0x4DE0  /* Jasper Lake Point N */
 
diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index 2a3f2fd5df50..319158fd4393 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -68,6 +68,7 @@ static const struct pci_device_id mei_me_pci_tbl[] = {
 
 	{MEI_PCI_DEVICE(MEI_DEV_ID_SPT, MEI_ME_PCH8_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_SPT_2, MEI_ME_PCH8_CFG)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_SPT_3, MEI_ME_PCH8_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_SPT_H, MEI_ME_PCH8_SPS_4_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_SPT_H_2, MEI_ME_PCH8_SPS_4_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_LBG, MEI_ME_PCH12_SPS_4_CFG)},
@@ -81,6 +82,7 @@ static const struct pci_device_id mei_me_pci_tbl[] = {
 
 	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP, MEI_ME_PCH8_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP_2, MEI_ME_PCH8_CFG)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP_3, MEI_ME_PCH8_CFG)},
 
 	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_LP, MEI_ME_PCH12_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_LP_3, MEI_ME_PCH8_CFG)},
@@ -94,6 +96,7 @@ static const struct pci_device_id mei_me_pci_tbl[] = {
 	{MEI_PCI_DEVICE(MEI_DEV_ID_CMP_H_3, MEI_ME_PCH8_CFG)},
 
 	{MEI_PCI_DEVICE(MEI_DEV_ID_ICP_LP, MEI_ME_PCH12_CFG)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_ICP_LP_3, MEI_ME_PCH12_CFG)},
 
 	{MEI_PCI_DEVICE(MEI_DEV_ID_TGP_LP, MEI_ME_PCH15_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_TGP_H, MEI_ME_PCH15_SPS_CFG)},
-- 
2.28.0

From e6812c7fe4d645c770c87071d6e30cb6b960c169 Mon Sep 17 00:00:00 2001
From: Dorian Stoll <dorian.stoll@tmsp.io>
Date: Thu, 6 Aug 2020 11:20:41 +0200
Subject: [PATCH] misc: Add support for Intel Precise Touch & Stylus

Based on https://github.com/linux-surface/intel-precise-touch/commit/0a4a44c2a9b676bd25d1cd916118dcfe3f447849

Signed-off-by: Dorian Stoll <dorian.stoll@tmsp.io>
Patchset: ipts
---
 drivers/misc/Kconfig          |   1 +
 drivers/misc/Makefile         |   1 +
 drivers/misc/ipts/Kconfig     |  17 ++
 drivers/misc/ipts/Makefile    |  12 ++
 drivers/misc/ipts/context.h   |  48 +++++
 drivers/misc/ipts/control.c   |  73 ++++++++
 drivers/misc/ipts/control.h   |  23 +++
 drivers/misc/ipts/mei.c       | 128 ++++++++++++++
 drivers/misc/ipts/protocol.h  | 319 ++++++++++++++++++++++++++++++++++
 drivers/misc/ipts/receiver.c  | 183 +++++++++++++++++++
 drivers/misc/ipts/receiver.h  |  17 ++
 drivers/misc/ipts/resources.c | 134 ++++++++++++++
 drivers/misc/ipts/resources.h |  18 ++
 drivers/misc/ipts/uapi.c      | 190 ++++++++++++++++++++
 drivers/misc/ipts/uapi.h      |  47 +++++
 15 files changed, 1211 insertions(+)
 create mode 100644 drivers/misc/ipts/Kconfig
 create mode 100644 drivers/misc/ipts/Makefile
 create mode 100644 drivers/misc/ipts/context.h
 create mode 100644 drivers/misc/ipts/control.c
 create mode 100644 drivers/misc/ipts/control.h
 create mode 100644 drivers/misc/ipts/mei.c
 create mode 100644 drivers/misc/ipts/protocol.h
 create mode 100644 drivers/misc/ipts/receiver.c
 create mode 100644 drivers/misc/ipts/receiver.h
 create mode 100644 drivers/misc/ipts/resources.c
 create mode 100644 drivers/misc/ipts/resources.h
 create mode 100644 drivers/misc/ipts/uapi.c
 create mode 100644 drivers/misc/ipts/uapi.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index e1b1ba5e2b92..be901ffc66fe 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -472,4 +472,5 @@ source "drivers/misc/ocxl/Kconfig"
 source "drivers/misc/cardreader/Kconfig"
 source "drivers/misc/habanalabs/Kconfig"
 source "drivers/misc/uacce/Kconfig"
+source "drivers/misc/ipts/Kconfig"
 endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c7bd01ac6291..f97938d777e1 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,3 +57,4 @@ obj-$(CONFIG_PVPANIC)   	+= pvpanic.o
 obj-$(CONFIG_HABANA_AI)		+= habanalabs/
 obj-$(CONFIG_UACCE)		+= uacce/
 obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o
+obj-$(CONFIG_MISC_IPTS)		+= ipts/
diff --git a/drivers/misc/ipts/Kconfig b/drivers/misc/ipts/Kconfig
new file mode 100644
index 000000000000..83e2a930c396
--- /dev/null
+++ b/drivers/misc/ipts/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+config MISC_IPTS
+	tristate "Intel Precise Touch & Stylus"
+	depends on INTEL_MEI
+	help
+	  Say Y here if your system has a touchscreen using Intels
+	  Precise Touch & Stylus (IPTS) technology.
+
+	  If unsure say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ipts.
+
+	  Building this driver alone will not give you a working touchscreen.
+	  It only exposed a userspace API that can be used by a daemon to
+	  receive and process data from the touchscreen hardware.
diff --git a/drivers/misc/ipts/Makefile b/drivers/misc/ipts/Makefile
new file mode 100644
index 000000000000..8f58b9adbc94
--- /dev/null
+++ b/drivers/misc/ipts/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for the IPTS touchscreen driver
+#
+
+obj-$(CONFIG_MISC_IPTS) += ipts.o
+ipts-objs := control.o
+ipts-objs += mei.o
+ipts-objs += receiver.o
+ipts-objs += resources.o
+ipts-objs += uapi.o
+
diff --git a/drivers/misc/ipts/context.h b/drivers/misc/ipts/context.h
new file mode 100644
index 000000000000..6e8eba3a47e5
--- /dev/null
+++ b/drivers/misc/ipts/context.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_CONTEXT_H_
+#define _IPTS_CONTEXT_H_
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/types.h>
+
+#include "protocol.h"
+
+enum ipts_host_status {
+	IPTS_HOST_STATUS_STARTING,
+	IPTS_HOST_STATUS_STARTED,
+	IPTS_HOST_STATUS_STOPPING,
+	IPTS_HOST_STATUS_STOPPED,
+};
+
+struct ipts_buffer_info {
+	u8 *address;
+	dma_addr_t dma_address;
+};
+
+struct ipts_context {
+	struct mei_cl_device *cldev;
+	struct device *dev;
+
+	bool restart;
+	enum ipts_host_status status;
+	struct ipts_get_device_info_rsp device_info;
+
+	struct ipts_buffer_info data[IPTS_BUFFERS];
+	struct ipts_buffer_info doorbell;
+
+	struct ipts_buffer_info feedback[IPTS_BUFFERS];
+	struct ipts_buffer_info workqueue;
+	struct ipts_buffer_info host2me;
+};
+
+#endif /* _IPTS_CONTEXT_H_ */
+
diff --git a/drivers/misc/ipts/control.c b/drivers/misc/ipts/control.c
new file mode 100644
index 000000000000..98787d7ea292
--- /dev/null
+++ b/drivers/misc/ipts/control.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#include <linux/mei_cl_bus.h>
+
+#include "context.h"
+#include "protocol.h"
+#include "resources.h"
+#include "uapi.h"
+
+int ipts_control_send(struct ipts_context *ipts,
+		u32 code, void *payload, size_t size)
+{
+	int ret;
+	struct ipts_command cmd;
+
+	memset(&cmd, 0, sizeof(struct ipts_command));
+	cmd.code = code;
+
+	if (payload && size > 0)
+		memcpy(&cmd.payload, payload, size);
+
+	ret = mei_cldev_send(ipts->cldev, (u8 *)&cmd, sizeof(cmd.code) + size);
+	if (ret >= 0 || ret == -EINTR)
+		return 0;
+
+	dev_err(ipts->dev, "Error while sending: 0x%X:%d\n", code, ret);
+	return ret;
+}
+
+int ipts_control_start(struct ipts_context *ipts)
+{
+	if (ipts->status != IPTS_HOST_STATUS_STOPPED)
+		return -EBUSY;
+
+	dev_info(ipts->dev, "Starting IPTS\n");
+	ipts->status = IPTS_HOST_STATUS_STARTING;
+	ipts->restart = false;
+
+	ipts_uapi_link(ipts);
+	return ipts_control_send(ipts, IPTS_CMD_GET_DEVICE_INFO, NULL, 0);
+}
+
+int ipts_control_stop(struct ipts_context *ipts)
+{
+	if (ipts->status == IPTS_HOST_STATUS_STOPPING)
+		return -EBUSY;
+
+	if (ipts->status == IPTS_HOST_STATUS_STOPPED)
+		return -EBUSY;
+
+	dev_info(ipts->dev, "Stopping IPTS\n");
+	ipts->status = IPTS_HOST_STATUS_STOPPING;
+
+	ipts_uapi_unlink();
+	ipts_resources_free(ipts);
+	return ipts_control_send(ipts, IPTS_CMD_CLEAR_MEM_WINDOW, NULL, 0);
+}
+
+int ipts_control_restart(struct ipts_context *ipts)
+{
+	if (ipts->restart)
+		return -EBUSY;
+
+	ipts->restart = true;
+	return ipts_control_stop(ipts);
+}
+
diff --git a/drivers/misc/ipts/control.h b/drivers/misc/ipts/control.h
new file mode 100644
index 000000000000..2b3172c16063
--- /dev/null
+++ b/drivers/misc/ipts/control.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_CONTROL_H_
+#define _IPTS_CONTROL_H_
+
+#include <linux/types.h>
+
+#include "context.h"
+
+int ipts_control_send(struct ipts_context *ipts,
+		u32 cmd, void *payload, size_t size);
+int ipts_control_start(struct ipts_context *ipts);
+int ipts_control_restart(struct ipts_context *ipts);
+int ipts_control_stop(struct ipts_context *ipts);
+
+#endif /* _IPTS_CONTROL_H_ */
+
diff --git a/drivers/misc/ipts/mei.c b/drivers/misc/ipts/mei.c
new file mode 100644
index 000000000000..b74e45c55b62
--- /dev/null
+++ b/drivers/misc/ipts/mei.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/slab.h>
+
+#include "context.h"
+#include "control.h"
+#include "protocol.h"
+#include "receiver.h"
+#include "uapi.h"
+
+static int ipts_mei_set_dma_mask(struct mei_cl_device *cldev)
+{
+	int ret;
+
+	ret = dma_coerce_mask_and_coherent(&cldev->dev, DMA_BIT_MASK(64));
+	if (!ret)
+		return 0;
+
+	return dma_coerce_mask_and_coherent(&cldev->dev, DMA_BIT_MASK(32));
+}
+
+static int ipts_mei_probe(struct mei_cl_device *cldev,
+		const struct mei_cl_device_id *id)
+{
+	int ret;
+	struct ipts_context *ipts;
+
+	if (ipts_mei_set_dma_mask(cldev)) {
+		dev_err(&cldev->dev, "Failed to set DMA mask for IPTS\n");
+		return -EFAULT;
+	}
+
+	ret = mei_cldev_enable(cldev);
+	if (ret) {
+		dev_err(&cldev->dev, "Failed to enable MEI device: %d\n", ret);
+		return ret;
+	}
+
+	ipts = kzalloc(sizeof(struct ipts_context), GFP_KERNEL);
+	if (!ipts) {
+		mei_cldev_disable(cldev);
+		return -ENOMEM;
+	}
+
+	ipts->cldev = cldev;
+	ipts->dev = &cldev->dev;
+	ipts->status = IPTS_HOST_STATUS_STOPPED;
+
+	mei_cldev_set_drvdata(cldev, ipts);
+	mei_cldev_register_rx_cb(cldev, ipts_receiver_callback);
+
+	return ipts_control_start(ipts);
+}
+
+static int ipts_mei_remove(struct mei_cl_device *cldev)
+{
+	int i;
+	struct ipts_context *ipts = mei_cldev_get_drvdata(cldev);
+
+	ipts_control_stop(ipts);
+
+	for (i = 0; i < 20; i++) {
+		if (ipts->status == IPTS_HOST_STATUS_STOPPED)
+			break;
+
+		msleep(25);
+	}
+
+	mei_cldev_disable(cldev);
+	kfree(ipts);
+
+	return 0;
+}
+
+static struct mei_cl_device_id ipts_mei_device_id_table[] = {
+	{ "", IPTS_MEI_UUID, MEI_CL_VERSION_ANY },
+	{ },
+};
+MODULE_DEVICE_TABLE(mei, ipts_mei_device_id_table);
+
+static struct mei_cl_driver ipts_mei_driver = {
+	.id_table = ipts_mei_device_id_table,
+	.name = "ipts",
+	.probe = ipts_mei_probe,
+	.remove = ipts_mei_remove,
+};
+
+static int __init ipts_mei_init(void)
+{
+	int ret;
+
+	ret = ipts_uapi_init();
+	if (ret)
+		return ret;
+
+	ret = mei_cldev_driver_register(&ipts_mei_driver);
+	if (ret) {
+		ipts_uapi_free();
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit ipts_mei_exit(void)
+{
+	mei_cldev_driver_unregister(&ipts_mei_driver);
+	ipts_uapi_free();
+}
+
+MODULE_DESCRIPTION("IPTS touchscreen driver");
+MODULE_AUTHOR("Dorian Stoll <dorian.stoll@tmsp.io>");
+MODULE_LICENSE("GPL");
+
+module_init(ipts_mei_init);
+module_exit(ipts_mei_exit);
+
diff --git a/drivers/misc/ipts/protocol.h b/drivers/misc/ipts/protocol.h
new file mode 100644
index 000000000000..2e179cbb9af3
--- /dev/null
+++ b/drivers/misc/ipts/protocol.h
@@ -0,0 +1,319 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_PROTOCOL_H_
+#define _IPTS_PROTOCOL_H_
+
+#include <linux/types.h>
+
+/*
+ * The MEI client ID for IPTS functionality.
+ */
+#define IPTS_MEI_UUID UUID_LE(0x3e8d0870, 0x271a, 0x4208, \
+		0x8e, 0xb5, 0x9a, 0xcb, 0x94, 0x02, 0xae, 0x04)
+
+/*
+ * Queries the device for vendor specific information.
+ *
+ * The command must not contain any payload.
+ * The response will contain struct ipts_get_device_info_rsp as payload.
+ */
+#define IPTS_CMD_GET_DEVICE_INFO 0x00000001
+#define IPTS_RSP_GET_DEVICE_INFO 0x80000001
+
+/*
+ * Sets the mode that IPTS will operate in.
+ *
+ * The command must contain struct ipts_set_mode_cmd as payload.
+ * The response will not contain any payload.
+ */
+#define IPTS_CMD_SET_MODE 0x00000002
+#define IPTS_RSP_SET_MODE 0x80000002
+
+/*
+ * Configures the memory buffers that the ME will use
+ * for passing data to the host.
+ *
+ * The command must contain struct ipts_set_mem_window_cmd as payload.
+ * The response will not contain any payload.
+ */
+#define IPTS_CMD_SET_MEM_WINDOW 0x00000003
+#define IPTS_RSP_SET_MEM_WINDOW 0x80000003
+
+/*
+ * Signals that the host is ready to receive data to the ME.
+ *
+ * The command must not contain any payload.
+ * The response will not contain any payload.
+ */
+#define IPTS_CMD_READY_FOR_DATA 0x00000005
+#define IPTS_RSP_READY_FOR_DATA 0x80000005
+
+/*
+ * Signals that a buffer can be refilled to the ME.
+ *
+ * The command must contain struct ipts_feedback_cmd as payload.
+ * The response will not contain any payload.
+ */
+#define IPTS_CMD_FEEDBACK 0x00000006
+#define IPTS_RSP_FEEDBACK 0x80000006
+
+/*
+ * Resets the data flow from the ME to the hosts and
+ * clears the buffers that were set with SET_MEM_WINDOW.
+ *
+ * The command must not contain any payload.
+ * The response will not contain any payload.
+ */
+#define IPTS_CMD_CLEAR_MEM_WINDOW 0x00000007
+#define IPTS_RSP_CLEAR_MEM_WINDOW 0x80000007
+
+/*
+ * Singletouch mode is a fallback that does not support
+ * a stylus or more than one touch input. The data is
+ * received as a HID report with report ID 64.
+ */
+#define IPTS_MODE_SINGLETOUCH 0x0
+
+/*
+ * Multitouch mode is the "proper" operation mode for IPTS. It will
+ * return stylus data as well as capacitive heatmap touch data.
+ * This data needs to be processed in userspace before it can be used.
+ */
+#define IPTS_MODE_MULTITOUCH 0x1
+
+/*
+ * Operation completed successfully.
+ */
+#define IPTS_STATUS_SUCCESS 0x0
+
+/*
+ * Command contained a payload with invalid parameters.
+ */
+#define IPTS_STATUS_INVALID_PARAMS 0x1
+
+/*
+ * ME was unable to validate buffer addresses supplied by the host.
+ */
+#define IPTS_STATUS_ACCESS_DENIED 0x2
+
+/*
+ * Command contained a payload with an invalid size.
+ */
+#define IPTS_STATUS_CMD_SIZE_ERROR 0x3
+
+/*
+ * Buffer addresses have not been set, or the
+ * device is not ready for operation yet.
+ */
+#define IPTS_STATUS_NOT_READY 0x4
+
+/*
+ * There is an outstanding command of the same type. The host must
+ * wait for a response before sending another command of the same type.
+ */
+#define IPTS_STATUS_REQUEST_OUTSTANDING 0x5
+
+/*
+ * No sensor could be found. Either no sensor is connected, it has not
+ * been initialized yet, or the system is improperly configured.
+ */
+#define IPTS_STATUS_NO_SENSOR_FOUND 0x6
+
+/*
+ * Not enough free memory for requested operation.
+ */
+#define IPTS_STATUS_OUT_OF_MEMORY 0x7
+
+/*
+ * An unexpected error occured.
+ */
+#define IPTS_STATUS_INTERNAL_ERROR 0x8
+
+/*
+ * The sensor has been disabled / reset and must be reinitialized.
+ */
+#define IPTS_STATUS_SENSOR_DISABLED 0x9
+
+/*
+ * Compatibility revision check between sensor and ME failed.
+ * The host can ignore this error and attempt to continue.
+ */
+#define IPTS_STATUS_COMPAT_CHECK_FAIL 0xA
+
+/*
+ * The sensor went through a reset initiated by the ME / the host.
+ */
+#define IPTS_STATUS_SENSOR_EXPECTED_RESET 0xB
+
+/*
+ * The sensor went through an unexpected reset.
+ */
+#define IPTS_STATUS_SENSOR_UNEXPECTED_RESET 0xC
+
+/*
+ * Requested sensor reset failed to complete.
+ */
+#define IPTS_STATUS_RESET_FAILED 0xD
+
+/*
+ * The operation timed out.
+ */
+#define IPTS_STATUS_TIMEOUT 0xE
+
+/*
+ * Test mode pattern did not match expected values.
+ */
+#define IPTS_STATUS_TEST_MODE_FAIL 0xF
+
+/*
+ * The sensor reported fatal error during reset sequence.
+ * Futher progress is not possible.
+ */
+#define IPTS_STATUS_SENSOR_FAIL_FATAL 0x10
+
+/*
+ * The sensor reported fatal error during reset sequence.
+ * The host can attempt to continue.
+ */
+#define IPTS_STATUS_SENSOR_FAIL_NONFATAL 0x11
+
+/*
+ * The sensor reported invalid capabilities.
+ */
+#define IPTS_STATUS_INVALID_DEVICE_CAPS 0x12
+
+/*
+ * The command cannot be completed until Quiesce IO flow has completed.
+ */
+#define IPTS_STATUS_QUIESCE_IO_IN_PROGRESS 0x13
+
+/*
+ * The amount of buffers that is used for IPTS
+ */
+#define IPTS_BUFFERS 16
+
+#define IPTS_WORKQUEUE_SIZE 8192
+#define IPTS_WORKQUEUE_ITEM_SIZE 16
+
+/**
+ * struct ipts_set_mode_cmd - Payload for the SET_MODE command.
+ *
+ * @mode: The mode that IPTS should operate in. (IPTS_MODE_*)
+ *
+ * This driver only supports multitouch mode. Singletouch mode
+ * requires a different control flow that is not implemented.
+ */
+struct ipts_set_mode_cmd {
+	u32 mode;
+	u8 reserved[12];
+} __packed;
+
+/**
+ * struct ipts_set_mem_window_cmd - Payload for the SET_MEM_WINDOW command.
+ *
+ * @data_buffer_addr_lower:     Lower 32 bits of the data buffer addresses.
+ * @data_buffer_addr_upper:     Upper 32 bits of the data buffer addresses.
+ * @workqueue_addr_lower:       Lower 32 bits of the workqueue buffer address.
+ * @workqueue_addr_upper:       Upper 32 bits of the workqueue buffer address.
+ * @doorbell_addr_lower:        Lower 32 bits of the doorbell buffer address.
+ * @doorbell_addr_upper:        Upper 32 bits of the doorbell buffer address.
+ * @feedback_buffer_addr_lower: Lower 32 bits of the feedback buffer addresses.
+ * @feedback_buffer_addr_upper: Upper 32 bits of the feedback buffer addresses.
+ * @host2me_addr_lower:         Lower 32 bits of the host2me buffer address.
+ * @host2me_addr_upper:         Upper 32 bits of the host2me buffer address.
+ * @workqueue_item_size:        Constant value. (IPTS_WORKQUEUE_ITEM_SIZE)
+ * @workqueue_size:             Constant value. (IPTS_WORKQUEUE_SIZE)
+ *
+ * The data buffers are buffers that get filled with touch data by the ME.
+ * The doorbell buffer is a u32 that gets incremented by the ME once a data
+ * buffer has been filled with new data.
+ *
+ * The other buffers are required for using GuC submission with binary
+ * firmware. Since support for GuC submission has been dropped from i915,
+ * they are not used anymore, but they need to be allocated to ensure proper
+ * operation.
+ */
+struct ipts_set_mem_window_cmd {
+	u32 data_buffer_addr_lower[IPTS_BUFFERS];
+	u32 data_buffer_addr_upper[IPTS_BUFFERS];
+	u32 workqueue_addr_lower;
+	u32 workqueue_addr_upper;
+	u32 doorbell_addr_lower;
+	u32 doorbell_addr_upper;
+	u32 feedback_buffer_addr_lower[IPTS_BUFFERS];
+	u32 feedback_buffer_addr_upper[IPTS_BUFFERS];
+	u32 host2me_addr_lower;
+	u32 host2me_addr_upper;
+	u32 host2me_size;
+	u8 reserved1;
+	u8 workqueue_item_size;
+	u16 workqueue_size;
+	u8 reserved[32];
+} __packed;
+
+/**
+ * struct ipts_feedback_cmd - Payload for the FEEDBACK command.
+ *
+ * @buffer: The buffer that the ME should refill.
+ */
+struct ipts_feedback_cmd {
+	u32 buffer;
+	u8 reserved[12];
+} __packed;
+
+/**
+ * struct ipts_command - A message sent from the host to the ME.
+ *
+ * @code:    The message code describing the command (IPTS_CMD_*)
+ * @payload: Payload for the command, or 0 if no payload is required.
+ */
+struct ipts_command {
+	u32 code;
+	u8 payload[320];
+} __packed;
+
+/**
+ * struct ipts_device_info - Payload for the GET_DEVICE_INFO response.
+ *
+ * @vendor_id:     Vendor ID of the touch sensor.
+ * @device_id:     Device ID of the touch sensor.
+ * @hw_rev:        Hardware revision of the touch sensor.
+ * @fw_rev:        Firmware revision of the touch sensor.
+ * @data_size:     Required size of one data buffer.
+ * @feedback_size: Required size of one feedback buffer.
+ * @mode:          Current operation mode of IPTS (IPTS_MODE_*)
+ * @max_contacts:  The amount of concurrent touches supported by the sensor.
+ */
+struct ipts_get_device_info_rsp {
+	u16 vendor_id;
+	u16 device_id;
+	u32 hw_rev;
+	u32 fw_rev;
+	u32 data_size;
+	u32 feedback_size;
+	u32 mode;
+	u8 max_contacts;
+	u8 reserved[19];
+} __packed;
+
+/**
+ * struct ipts_response - A message sent from the ME to the host.
+ *
+ * @code:    The message code describing the response (IPTS_RSP_*)
+ * @status:  The status code returned by the command. (IPTS_STATUS_*)
+ * @payload: Payload returned by the command.
+ */
+struct ipts_response {
+	u32 code;
+	u32 status;
+	u8 payload[80];
+} __packed;
+
+#endif /* _IPTS_PROTOCOL_H_ */
+
diff --git a/drivers/misc/ipts/receiver.c b/drivers/misc/ipts/receiver.c
new file mode 100644
index 000000000000..3660a1dcfff9
--- /dev/null
+++ b/drivers/misc/ipts/receiver.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#include <linux/mei_cl_bus.h>
+#include <linux/types.h>
+
+#include "context.h"
+#include "control.h"
+#include "protocol.h"
+#include "resources.h"
+
+static int ipts_receiver_handle_get_device_info(struct ipts_context *ipts,
+		struct ipts_response *rsp)
+{
+	struct ipts_set_mode_cmd cmd;
+
+	memcpy(&ipts->device_info, rsp->payload,
+			sizeof(struct ipts_get_device_info_rsp));
+
+	memset(&cmd, 0, sizeof(struct ipts_set_mode_cmd));
+	cmd.mode = IPTS_MODE_MULTITOUCH;
+
+	return ipts_control_send(ipts, IPTS_CMD_SET_MODE,
+			&cmd, sizeof(struct ipts_set_mode_cmd));
+}
+
+static int ipts_receiver_handle_set_mode(struct ipts_context *ipts)
+{
+	int i, ret;
+	struct ipts_set_mem_window_cmd cmd;
+
+	ret = ipts_resources_alloc(ipts);
+	if (ret) {
+		dev_err(ipts->dev, "Failed to allocate resources\n");
+		return ret;
+	}
+
+	memset(&cmd, 0, sizeof(struct ipts_set_mem_window_cmd));
+
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		cmd.data_buffer_addr_lower[i] =
+			lower_32_bits(ipts->data[i].dma_address);
+
+		cmd.data_buffer_addr_upper[i] =
+			upper_32_bits(ipts->data[i].dma_address);
+
+		cmd.feedback_buffer_addr_lower[i] =
+			lower_32_bits(ipts->feedback[i].dma_address);
+
+		cmd.feedback_buffer_addr_upper[i] =
+			upper_32_bits(ipts->feedback[i].dma_address);
+	}
+
+	cmd.workqueue_addr_lower = lower_32_bits(ipts->workqueue.dma_address);
+	cmd.workqueue_addr_upper = upper_32_bits(ipts->workqueue.dma_address);
+
+	cmd.doorbell_addr_lower = lower_32_bits(ipts->doorbell.dma_address);
+	cmd.doorbell_addr_upper = upper_32_bits(ipts->doorbell.dma_address);
+
+	cmd.host2me_addr_lower = lower_32_bits(ipts->host2me.dma_address);
+	cmd.host2me_addr_upper = upper_32_bits(ipts->host2me.dma_address);
+
+	cmd.workqueue_size = IPTS_WORKQUEUE_SIZE;
+	cmd.workqueue_item_size = IPTS_WORKQUEUE_ITEM_SIZE;
+
+	return ipts_control_send(ipts, IPTS_CMD_SET_MEM_WINDOW,
+			&cmd, sizeof(struct ipts_set_mem_window_cmd));
+}
+
+static int ipts_receiver_handle_set_mem_window(struct ipts_context *ipts)
+{
+	dev_info(ipts->dev, "Device %04hX:%04hX ready\n",
+			ipts->device_info.vendor_id,
+			ipts->device_info.device_id);
+	ipts->status = IPTS_HOST_STATUS_STARTED;
+
+	return ipts_control_send(ipts, IPTS_CMD_READY_FOR_DATA, NULL, 0);
+}
+
+static int ipts_receiver_handle_clear_mem_window(struct ipts_context *ipts)
+{
+	if (ipts->restart)
+		return ipts_control_start(ipts);
+
+	ipts->status = IPTS_HOST_STATUS_STOPPED;
+	return 0;
+}
+
+static bool ipts_receiver_handle_error(struct ipts_context *ipts,
+		struct ipts_response *rsp)
+{
+	bool error;
+
+	switch (rsp->status) {
+	case IPTS_STATUS_SUCCESS:
+	case IPTS_STATUS_COMPAT_CHECK_FAIL:
+		error = false;
+		break;
+	case IPTS_STATUS_INVALID_PARAMS:
+		error = rsp->code != IPTS_RSP_FEEDBACK;
+		break;
+	case IPTS_STATUS_SENSOR_DISABLED:
+		error = ipts->status != IPTS_HOST_STATUS_STOPPING;
+		break;
+	default:
+		error = true;
+		break;
+	}
+
+	if (!error)
+		return false;
+
+	dev_err(ipts->dev, "Command 0x%08x failed: %d\n",
+			rsp->code, rsp->status);
+
+	if (rsp->code == IPTS_STATUS_SENSOR_UNEXPECTED_RESET) {
+		dev_err(ipts->dev, "Sensor was reset\n");
+
+		if (ipts_control_restart(ipts))
+			dev_err(ipts->dev, "Failed to restart IPTS\n");
+	}
+
+	return true;
+}
+
+static void ipts_receiver_handle_response(struct ipts_context *ipts,
+		struct ipts_response *rsp)
+{
+	int ret;
+
+	if (ipts_receiver_handle_error(ipts, rsp))
+		return;
+
+	switch (rsp->code) {
+	case IPTS_RSP_GET_DEVICE_INFO:
+		ret = ipts_receiver_handle_get_device_info(ipts, rsp);
+		break;
+	case IPTS_RSP_SET_MODE:
+		ret = ipts_receiver_handle_set_mode(ipts);
+		break;
+	case IPTS_RSP_SET_MEM_WINDOW:
+		ret = ipts_receiver_handle_set_mem_window(ipts);
+		break;
+	case IPTS_RSP_CLEAR_MEM_WINDOW:
+		ret = ipts_receiver_handle_clear_mem_window(ipts);
+		break;
+	default:
+		ret = 0;
+		break;
+	}
+
+	if (!ret)
+		return;
+
+	dev_err(ipts->dev, "Error while handling response 0x%08x: %d\n",
+			rsp->code, ret);
+
+	if (ipts_control_stop(ipts))
+		dev_err(ipts->dev, "Failed to stop IPTS\n");
+}
+
+void ipts_receiver_callback(struct mei_cl_device *cldev)
+{
+	int ret;
+	struct ipts_response rsp;
+	struct ipts_context *ipts;
+
+	ipts = mei_cldev_get_drvdata(cldev);
+
+	ret = mei_cldev_recv(cldev, (u8 *)&rsp, sizeof(struct ipts_response));
+	if (ret <= 0) {
+		dev_err(ipts->dev, "Error while reading response: %d\n", ret);
+		return;
+	}
+
+	ipts_receiver_handle_response(ipts, &rsp);
+}
+
diff --git a/drivers/misc/ipts/receiver.h b/drivers/misc/ipts/receiver.h
new file mode 100644
index 000000000000..c061d57a9320
--- /dev/null
+++ b/drivers/misc/ipts/receiver.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_RECEIVER_H_
+#define _IPTS_RECEIVER_H_
+
+#include <linux/mei_cl_bus.h>
+
+void ipts_receiver_callback(struct mei_cl_device *cldev);
+
+#endif /* _IPTS_RECEIVER_H_ */
+
diff --git a/drivers/misc/ipts/resources.c b/drivers/misc/ipts/resources.c
new file mode 100644
index 000000000000..bcf4dd8d7e95
--- /dev/null
+++ b/drivers/misc/ipts/resources.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#include <linux/dma-mapping.h>
+
+#include "context.h"
+
+void ipts_resources_free(struct ipts_context *ipts)
+{
+	int i;
+	struct ipts_buffer_info *buffers;
+
+	u32 data_buffer_size = ipts->device_info.data_size;
+	u32 feedback_buffer_size = ipts->device_info.feedback_size;
+
+	buffers = ipts->data;
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		if (!buffers[i].address)
+			continue;
+
+		dma_free_coherent(ipts->dev, data_buffer_size,
+				buffers[i].address, buffers[i].dma_address);
+
+		buffers[i].address = NULL;
+		buffers[i].dma_address = 0;
+	}
+
+	buffers = ipts->feedback;
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		if (!buffers[i].address)
+			continue;
+
+		dma_free_coherent(ipts->dev, feedback_buffer_size,
+				buffers[i].address, buffers[i].dma_address);
+
+		buffers[i].address = NULL;
+		buffers[i].dma_address = 0;
+	}
+
+	if (ipts->doorbell.address) {
+		dma_free_coherent(ipts->dev, sizeof(u32),
+				ipts->doorbell.address,
+				ipts->doorbell.dma_address);
+
+		ipts->doorbell.address = NULL;
+		ipts->doorbell.dma_address = 0;
+	}
+
+	if (ipts->workqueue.address) {
+		dma_free_coherent(ipts->dev, sizeof(u32),
+				ipts->workqueue.address,
+				ipts->workqueue.dma_address);
+
+		ipts->workqueue.address = NULL;
+		ipts->workqueue.dma_address = 0;
+	}
+
+	if (ipts->host2me.address) {
+		dma_free_coherent(ipts->dev, feedback_buffer_size,
+				ipts->host2me.address,
+				ipts->host2me.dma_address);
+
+		ipts->host2me.address = NULL;
+		ipts->host2me.dma_address = 0;
+	}
+}
+
+int ipts_resources_alloc(struct ipts_context *ipts)
+{
+	int i;
+	struct ipts_buffer_info *buffers;
+
+	u32 data_buffer_size = ipts->device_info.data_size;
+	u32 feedback_buffer_size = ipts->device_info.feedback_size;
+
+	buffers = ipts->data;
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		buffers[i].address = dma_alloc_coherent(ipts->dev,
+				data_buffer_size,
+				&buffers[i].dma_address,
+				GFP_KERNEL);
+
+		if (!buffers[i].address)
+			goto release_resources;
+	}
+
+	buffers = ipts->feedback;
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		buffers[i].address = dma_alloc_coherent(ipts->dev,
+				feedback_buffer_size,
+				&buffers[i].dma_address,
+				GFP_KERNEL);
+
+		if (!buffers[i].address)
+			goto release_resources;
+	}
+
+	ipts->doorbell.address = dma_alloc_coherent(ipts->dev,
+			sizeof(u32),
+			&ipts->doorbell.dma_address,
+			GFP_KERNEL);
+
+	if (!ipts->doorbell.address)
+		goto release_resources;
+
+	ipts->workqueue.address = dma_alloc_coherent(ipts->dev,
+			sizeof(u32),
+			&ipts->workqueue.dma_address,
+			GFP_KERNEL);
+
+	if (!ipts->workqueue.address)
+		goto release_resources;
+
+	ipts->host2me.address = dma_alloc_coherent(ipts->dev,
+			feedback_buffer_size,
+			&ipts->host2me.dma_address,
+			GFP_KERNEL);
+
+	if (!ipts->workqueue.address)
+		goto release_resources;
+
+	return 0;
+
+release_resources:
+
+	ipts_resources_free(ipts);
+	return -ENOMEM;
+}
+
diff --git a/drivers/misc/ipts/resources.h b/drivers/misc/ipts/resources.h
new file mode 100644
index 000000000000..8f55af7aae0f
--- /dev/null
+++ b/drivers/misc/ipts/resources.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_RESOURCES_H_
+#define _IPTS_RESOURCES_H_
+
+#include "context.h"
+
+int ipts_resources_alloc(struct ipts_context *ipts);
+void ipts_resources_free(struct ipts_context *ipts);
+
+#endif /* _IPTS_RESOURCES_H_ */
+
diff --git a/drivers/misc/ipts/uapi.c b/drivers/misc/ipts/uapi.c
new file mode 100644
index 000000000000..1b59dbc9a1ad
--- /dev/null
+++ b/drivers/misc/ipts/uapi.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+
+#include "context.h"
+#include "control.h"
+#include "protocol.h"
+#include "uapi.h"
+
+struct ipts_uapi uapi;
+
+static ssize_t ipts_uapi_read(struct file *file, char __user *buf,
+		size_t count, loff_t *offset)
+{
+	int buffer;
+	int maxbytes;
+	struct ipts_context *ipts = uapi.ipts;
+
+	buffer = MINOR(file->f_path.dentry->d_inode->i_rdev);
+
+	if (!ipts || ipts->status != IPTS_HOST_STATUS_STARTED)
+		return -ENODEV;
+
+	maxbytes = ipts->device_info.data_size - *offset;
+	if (maxbytes <= 0 || count > maxbytes)
+		return -EINVAL;
+
+	if (copy_to_user(buf, ipts->data[buffer].address + *offset, count))
+		return -EFAULT;
+
+	return count;
+}
+
+static long ipts_uapi_ioctl_get_device_ready(struct ipts_context *ipts,
+		unsigned long arg)
+{
+	void __user *buffer = (void __user *)arg;
+	u8 ready = ipts->status == IPTS_HOST_STATUS_STARTED;
+
+	if (copy_to_user(buffer, &ready, sizeof(u8)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ipts_uapi_ioctl_get_device_info(struct ipts_context *ipts,
+		unsigned long arg)
+{
+	struct ipts_device_info info;
+	void __user *buffer = (void __user *)arg;
+
+	if (ipts->status != IPTS_HOST_STATUS_STARTED)
+		return -ENODEV;
+
+	info.vendor = ipts->device_info.vendor_id;
+	info.product = ipts->device_info.device_id;
+	info.version = ipts->device_info.fw_rev;
+	info.buffer_size = ipts->device_info.data_size;
+	info.max_contacts = ipts->device_info.max_contacts;
+
+	if (copy_to_user(buffer, &info, sizeof(struct ipts_device_info)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ipts_uapi_ioctl_get_doorbell(struct ipts_context *ipts,
+		unsigned long arg)
+{
+	void __user *buffer = (void __user *)arg;
+
+	if (ipts->status != IPTS_HOST_STATUS_STARTED)
+		return -ENODEV;
+
+	if (copy_to_user(buffer, ipts->doorbell.address, sizeof(u32)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ipts_uapi_ioctl_send_feedback(struct ipts_context *ipts,
+		struct file *file)
+{
+	int ret;
+	struct ipts_feedback_cmd cmd;
+
+	if (ipts->status != IPTS_HOST_STATUS_STARTED)
+		return -ENODEV;
+
+	memset(&cmd, 0, sizeof(struct ipts_feedback_cmd));
+	cmd.buffer = MINOR(file->f_path.dentry->d_inode->i_rdev);
+
+	ret = ipts_control_send(ipts, IPTS_CMD_FEEDBACK,
+				&cmd, sizeof(struct ipts_feedback_cmd));
+
+	if (ret)
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ipts_uapi_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
+{
+	struct ipts_context *ipts = uapi.ipts;
+
+	if (!ipts)
+		return -ENODEV;
+
+	switch (cmd) {
+	case IPTS_IOCTL_GET_DEVICE_READY:
+		return ipts_uapi_ioctl_get_device_ready(ipts, arg);
+	case IPTS_IOCTL_GET_DEVICE_INFO:
+		return ipts_uapi_ioctl_get_device_info(ipts, arg);
+	case IPTS_IOCTL_GET_DOORBELL:
+		return ipts_uapi_ioctl_get_doorbell(ipts, arg);
+	case IPTS_IOCTL_SEND_FEEDBACK:
+		return ipts_uapi_ioctl_send_feedback(ipts, file);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct file_operations ipts_uapi_fops = {
+	.owner = THIS_MODULE,
+	.read = ipts_uapi_read,
+	.unlocked_ioctl = ipts_uapi_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = ipts_uapi_ioctl,
+#endif
+};
+
+void ipts_uapi_link(struct ipts_context *ipts)
+{
+	uapi.ipts = ipts;
+}
+
+void ipts_uapi_unlink(void)
+{
+	uapi.ipts = NULL;
+}
+
+int ipts_uapi_init(void)
+{
+	int i, major;
+
+	alloc_chrdev_region(&uapi.dev, 0, IPTS_BUFFERS, "ipts");
+	uapi.class = class_create(THIS_MODULE, "ipts");
+
+	major = MAJOR(uapi.dev);
+
+	cdev_init(&uapi.cdev, &ipts_uapi_fops);
+	uapi.cdev.owner = THIS_MODULE;
+	cdev_add(&uapi.cdev, MKDEV(major, 0), IPTS_BUFFERS);
+
+	for (i = 0; i < IPTS_BUFFERS; i++) {
+		device_create(uapi.class, NULL,
+				MKDEV(major, i), NULL, "ipts/%d", i);
+	}
+
+	return 0;
+}
+
+void ipts_uapi_free(void)
+{
+	int i;
+	int major;
+
+	major = MAJOR(uapi.dev);
+
+	for (i = 0; i < IPTS_BUFFERS; i++)
+		device_destroy(uapi.class, MKDEV(major, i));
+
+	cdev_del(&uapi.cdev);
+
+	unregister_chrdev_region(MKDEV(major, 0), MINORMASK);
+	class_destroy(uapi.class);
+}
+
diff --git a/drivers/misc/ipts/uapi.h b/drivers/misc/ipts/uapi.h
new file mode 100644
index 000000000000..4c667bb6a7f2
--- /dev/null
+++ b/drivers/misc/ipts/uapi.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2020 Dorian Stoll
+ *
+ * Linux driver for Intel Precise Touch & Stylus
+ */
+
+#ifndef _IPTS_UAPI_H_
+#define _IPTS_UAPI_H_
+
+#include <linux/types.h>
+
+#include "context.h"
+
+struct ipts_uapi {
+	dev_t dev;
+	struct class *class;
+	struct cdev cdev;
+
+	struct ipts_context *ipts;
+};
+
+struct ipts_device_info {
+	__u16 vendor;
+	__u16 product;
+	__u32 version;
+	__u32 buffer_size;
+	__u8 max_contacts;
+
+	/* For future expansion */
+	__u8 reserved[19];
+};
+
+#define IPTS_IOCTL_GET_DEVICE_READY _IOR(0x86, 0x01, __u8)
+#define IPTS_IOCTL_GET_DEVICE_INFO  _IOR(0x86, 0x02, struct ipts_device_info)
+#define IPTS_IOCTL_GET_DOORBELL     _IOR(0x86, 0x03, __u32)
+#define IPTS_IOCTL_SEND_FEEDBACK    _IO(0x86, 0x04)
+
+void ipts_uapi_link(struct ipts_context *ipts);
+void ipts_uapi_unlink(void);
+
+int ipts_uapi_init(void);
+void ipts_uapi_free(void);
+
+#endif /* _IPTS_UAPI_H_ */
+
-- 
2.28.0