HID: intel-thc-hid: intel-quickspi: Add THC QuickSPI driver hid layer

Add HID Low level driver callbacks and hid probe function to register
QucikSPI as a HID driver, and external touch device as a HID device.

Co-developed-by: Xinpeng Sun <xinpeng.sun@intel.com>
Signed-off-by: Xinpeng Sun <xinpeng.sun@intel.com>
Signed-off-by: Even Xu <even.xu@intel.com>
Tested-by: Rui Zhang <rui1.zhang@intel.com>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

drivers/hid/intel-thc-hid/Makefile

@@ -11,5 +11,6 @@ intel-thc-objs += intel-thc/intel-thc-dma.o
 
 obj-$(CONFIG_INTEL_QUICKSPI) += intel-quickspi.o
 intel-quickspi-objs += intel-quickspi/pci-quickspi.o
+intel-quickspi-objs += intel-quickspi/quickspi-hid.o
 
 ccflags-y += -I $(src)/intel-thc

drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h

@@ -4,6 +4,8 @@
 #ifndef _QUICKSPI_DEV_H_
 #define _QUICKSPI_DEV_H_
 
+#include <linux/hid-over-spi.h>
+
 #define PCI_DEVICE_ID_INTEL_THC_MTL_DEVICE_ID_SPI_PORT1		0x7E49
 #define PCI_DEVICE_ID_INTEL_THC_MTL_DEVICE_ID_SPI_PORT2		0x7E4B
 #define PCI_DEVICE_ID_INTEL_THC_LNL_DEVICE_ID_SPI_PORT1		0xA849
@@ -38,24 +40,33 @@ struct quickspi_driver_data {
 struct device;
 struct pci_dev;
 struct thc_device;
+struct hid_device;
 
 /**
  * struct quickspi_device -  THC QuickSpi device struct
  * @dev: point to kernel device
  * @pdev: point to PCI device
  * @thc_hw: point to THC device
+ * @hid_dev: point to hid device
  * @driver_data: point to quickspi specific driver data
  * @state: THC SPI device state
  * @mem_addr: MMIO memory address
+ * @dev_desc: device descriptor for HIDSPI protocol
+ * @report_descriptor: store a copy of device report descriptor
  */
 struct quickspi_device {
 	struct device *dev;
 	struct pci_dev *pdev;
 	struct thc_device *thc_hw;
+	struct hid_device *hid_dev;
 	struct quickspi_driver_data *driver_data;
 	enum quickspi_dev_state state;
 
 	void __iomem *mem_addr;
+
+	struct hidspi_dev_descriptor dev_desc;
+
+	u8 *report_descriptor;
 };
 
 #endif /* _QUICKSPI_DEV_H_ */

drivers/hid/intel-thc-hid/intel-quickspi/quickspi-hid.c

@@ -0,0 +1,142 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2024 Intel Corporation */
+
+#include <linux/hid.h>
+#include <linux/input.h>
+
+#include "quickspi-dev.h"
+#include "quickspi-hid.h"
+
+/**
+ * quickspi_hid_parse() - HID core parse() callback
+ *
+ * @hid: HID device instance
+ *
+ * This function gets called during call to hid_add_device
+ *
+ * Return: 0 on success and non zero on error.
+ */
+static int quickspi_hid_parse(struct hid_device *hid)
+{
+	struct quickspi_device *qsdev = hid->driver_data;
+
+	if (qsdev->report_descriptor)
+		return hid_parse_report(hid, qsdev->report_descriptor,
+					le16_to_cpu(qsdev->dev_desc.rep_desc_len));
+
+	dev_err(qsdev->dev, "invalid report descriptor\n");
+	return -EINVAL;
+}
+
+static int quickspi_hid_start(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void quickspi_hid_stop(struct hid_device *hid)
+{
+}
+
+static int quickspi_hid_open(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void quickspi_hid_close(struct hid_device *hid)
+{
+}
+
+static int quickspi_hid_raw_request(struct hid_device *hid,
+				    unsigned char reportnum,
+				    __u8 *buf, size_t len,
+				    unsigned char rtype, int reqtype)
+{
+	return 0;
+}
+
+static int quickspi_hid_power(struct hid_device *hid, int lvl)
+{
+	return 0;
+}
+
+static struct hid_ll_driver quickspi_hid_ll_driver = {
+	.parse = quickspi_hid_parse,
+	.start = quickspi_hid_start,
+	.stop = quickspi_hid_stop,
+	.open = quickspi_hid_open,
+	.close = quickspi_hid_close,
+	.power = quickspi_hid_power,
+	.raw_request = quickspi_hid_raw_request,
+};
+
+/**
+ * quickspi_hid_probe() - Register HID low level driver
+ *
+ * @qsdev: point to quickspi device
+ *
+ * This function is used to allocate and add HID device.
+ *
+ * Return: 0 on success, non zero on error.
+ */
+int quickspi_hid_probe(struct quickspi_device *qsdev)
+{
+	struct hid_device *hid;
+	int ret;
+
+	hid = hid_allocate_device();
+	if (IS_ERR(hid))
+		return PTR_ERR(hid);
+
+	hid->ll_driver = &quickspi_hid_ll_driver;
+	hid->bus = BUS_PCI;
+	hid->dev.parent = qsdev->dev;
+	hid->driver_data = qsdev;
+	hid->version = le16_to_cpu(qsdev->dev_desc.version_id);
+	hid->vendor = le16_to_cpu(qsdev->dev_desc.vendor_id);
+	hid->product = le16_to_cpu(qsdev->dev_desc.product_id);
+	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", "quickspi-hid",
+		 hid->vendor, hid->product);
+
+	ret = hid_add_device(hid);
+	if (ret) {
+		hid_destroy_device(hid);
+		return ret;
+	}
+
+	qsdev->hid_dev = hid;
+
+	return 0;
+}
+
+/**
+ * quickspi_hid_remove() - Destroy HID device
+ *
+ * @qsdev: point to quickspi device
+ *
+ * Return: 0 on success, non zero on error.
+ */
+void quickspi_hid_remove(struct quickspi_device *qsdev)
+{
+	hid_destroy_device(qsdev->hid_dev);
+}
+
+/**
+ * quickspi_hid_send_report() - Send HID input report data to HID core
+ *
+ * @qsdev: point to quickspi device
+ * @data: point to input report data buffer
+ * @data_len: the length of input report data
+ *
+ * Return: 0 on success, non zero on error.
+ */
+int quickspi_hid_send_report(struct quickspi_device *qsdev,
+			     void *data, size_t data_len)
+{
+	int ret;
+
+	ret = hid_input_report(qsdev->hid_dev, HID_INPUT_REPORT, data, data_len, 1);
+	if (ret)
+		dev_err(qsdev->dev, "Failed to send HID input report, ret = %d.\n", ret);
+
+	return ret;
+}

drivers/hid/intel-thc-hid/intel-quickspi/quickspi-hid.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2024 Intel Corporation */
+
+#ifndef _QUICKSPI_HID_H_
+#define _QUICKSPI_HID_H_
+
+struct quickspi_device;
+
+int quickspi_hid_send_report(struct quickspi_device *qsdev,
+			     void *data, size_t data_size);
+int quickspi_hid_probe(struct quickspi_device *qsdev);
+void quickspi_hid_remove(struct quickspi_device *qsdev);
+
+#endif /* _QUICKSPI_HID_H_ */

include/linux/hid-over-spi.h

@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2024 Intel Corporation */
+
+#ifndef _HID_OVER_SPI_H_
+#define _HID_OVER_SPI_H_
+
+/**
+ * struct hidspi_dev_descriptor - HIDSPI device descriptor definition
+ * @dev_desc_len: The length of the complete device descriptor, fixed to 0x18 (24).
+ * @bcd_ver: The version number of the HIDSPI protocol supported.
+ *           In binary coded decimal (BCD) format. Must be fixed to 0x0300.
+ * @rep_desc_len: The length of the report descriptor
+ * @max_input_len: The length of the largest possible HID input (or feature) report
+ * @max_output_len: The length of the largest output (or feature) report
+ * @max_frag_len: The length of the largest fragment, where a fragment represents
+ *                the body of an input report.
+ * @vendor_id: Device manufacturers vendor ID
+ * @product_id: Device unique model/product ID
+ * @version_id: Device’s unique version
+ * @flags: Specify flags for the device’s operation
+ * @reserved: Reserved and should be 0
+ */
+struct hidspi_dev_descriptor {
+	__le16 dev_desc_len;
+	__le16 bcd_ver;
+	__le16 rep_desc_len;
+	__le16 max_input_len;
+	__le16 max_output_len;
+	__le16 max_frag_len;
+	__le16 vendor_id;
+	__le16 product_id;
+	__le16 version_id;
+	__le16 flags;
+	__le32 reserved;
+};
+
+#endif /* _HID_OVER_SPI_H_ */