// SPDX-License-Identifier: GPL-2.0 /* * HID class driver for the Greybus. * * Copyright 2014 Google Inc. * Copyright 2014 Linaro Ltd. */ #include <linux/bitops.h> #include <linux/hid.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> #include "greybus.h" /* Greybus HID device's structure */ struct gb_hid { struct gb_bundle *bundle; struct gb_connection *connection; struct hid_device *hid; struct gb_hid_desc_response hdesc; unsigned long flags; #define GB_HID_STARTED 0x01 #define GB_HID_READ_PENDING 0x04 unsigned int bufsize; char *inbuf; }; /* Routines to get controller's information over greybus */ /* Operations performed on greybus */ static int gb_hid_get_desc(struct gb_hid *ghid) { return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_DESC, NULL, 0, &ghid->hdesc, sizeof(ghid->hdesc)); } static int gb_hid_get_report_desc(struct gb_hid *ghid, char *rdesc) { int ret; ret = gb_pm_runtime_get_sync(ghid->bundle); if (ret) return ret; ret = gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT_DESC, NULL, 0, rdesc, le16_to_cpu(ghid->hdesc.wReportDescLength)); gb_pm_runtime_put_autosuspend(ghid->bundle); return ret; } static int gb_hid_set_power(struct gb_hid *ghid, int type) { int ret; ret = gb_pm_runtime_get_sync(ghid->bundle); if (ret) return ret; ret = gb_operation_sync(ghid->connection, type, NULL, 0, NULL, 0); gb_pm_runtime_put_autosuspend(ghid->bundle); return ret; } static int gb_hid_get_report(struct gb_hid *ghid, u8 report_type, u8 report_id, unsigned char *buf, int len) { struct gb_hid_get_report_request request; int ret; ret = gb_pm_runtime_get_sync(ghid->bundle); if (ret) return ret; request.report_type = report_type; request.report_id = report_id; ret = gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT, &request, sizeof(request), buf, len); gb_pm_runtime_put_autosuspend(ghid->bundle); return ret; } static int gb_hid_set_report(struct gb_hid *ghid, u8 report_type, u8 report_id, unsigned char *buf, int len) { struct gb_hid_set_report_request *request; struct gb_operation *operation; int ret, size = sizeof(*request) + len - 1; ret = gb_pm_runtime_get_sync(ghid->bundle); if (ret) return ret; operation = gb_operation_create(ghid->connection, GB_HID_TYPE_SET_REPORT, size, 0, GFP_KERNEL); if (!operation) { gb_pm_runtime_put_autosuspend(ghid->bundle); return -ENOMEM; } request = operation->request->payload; request->report_type = report_type; request->report_id = report_id; memcpy(request->report, buf, len); ret = gb_operation_request_send_sync(operation); if (ret) { dev_err(&operation->connection->bundle->dev, "failed to set report: %d\n", ret); } else { ret = len; } gb_operation_put(operation); gb_pm_runtime_put_autosuspend(ghid->bundle); return ret; } static int gb_hid_request_handler(struct gb_operation *op) { struct gb_connection *connection = op->connection; struct gb_hid *ghid = gb_connection_get_data(connection); struct gb_hid_input_report_request *request = op->request->payload; if (op->type != GB_HID_TYPE_IRQ_EVENT) { dev_err(&connection->bundle->dev, "unsupported unsolicited request\n"); return -EINVAL; } if (test_bit(GB_HID_STARTED, &ghid->flags)) hid_input_report(ghid->hid, HID_INPUT_REPORT, request->report, op->request->payload_size, 1); return 0; } static int gb_hid_report_len(struct hid_report *report) { return ((report->size - 1) >> 3) + 1 + report->device->report_enum[report->type].numbered; } static void gb_hid_find_max_report(struct hid_device *hid, unsigned int type, unsigned int *max) { struct hid_report *report; unsigned int size; list_for_each_entry(report, &hid->report_enum[type].report_list, list) { size = gb_hid_report_len(report); if (*max < size) *max = size; } } static void gb_hid_free_buffers(struct gb_hid *ghid) { kfree(ghid->inbuf); ghid->inbuf = NULL; ghid->bufsize = 0; } static int gb_hid_alloc_buffers(struct gb_hid *ghid, size_t bufsize) { ghid->inbuf = kzalloc(bufsize, GFP_KERNEL); if (!ghid->inbuf) return -ENOMEM; ghid->bufsize = bufsize; return 0; } /* Routines dealing with reports */ static void gb_hid_init_report(struct gb_hid *ghid, struct hid_report *report) { unsigned int size; size = gb_hid_report_len(report); if (gb_hid_get_report(ghid, report->type, report->id, ghid->inbuf, size)) return; /* * hid->driver_lock is held as we are in probe function, * we just need to setup the input fields, so using * hid_report_raw_event is safe. */ hid_report_raw_event(ghid->hid, report->type, ghid->inbuf, size, 1); } static void gb_hid_init_reports(struct gb_hid *ghid) { struct hid_device *hid = ghid->hid; struct hid_report *report; list_for_each_entry(report, &hid->report_enum[HID_INPUT_REPORT].report_list, list) gb_hid_init_report(ghid, report); list_for_each_entry(report, &hid->report_enum[HID_FEATURE_REPORT].report_list, list) gb_hid_init_report(ghid, report); } static int __gb_hid_get_raw_report(struct hid_device *hid, unsigned char report_number, __u8 *buf, size_t count, unsigned char report_type) { struct gb_hid *ghid = hid->driver_data; int ret; if (report_type == HID_OUTPUT_REPORT) return -EINVAL; ret = gb_hid_get_report(ghid, report_type, report_number, buf, count); if (!ret) ret = count; return ret; } static int __gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf, size_t len, unsigned char report_type) { struct gb_hid *ghid = hid->driver_data; int report_id = buf[0]; int ret; if (report_type == HID_INPUT_REPORT) return -EINVAL; if (report_id) { buf++; len--; } ret = gb_hid_set_report(ghid, report_type, report_id, buf, len); if (report_id && ret >= 0) ret++; /* add report_id to the number of transfered bytes */ return 0; } static int gb_hid_raw_request(struct hid_device *hid, unsigned char reportnum, __u8 *buf, size_t len, unsigned char rtype, int reqtype) { switch (reqtype) { case HID_REQ_GET_REPORT: return __gb_hid_get_raw_report(hid, reportnum, buf, len, rtype); case HID_REQ_SET_REPORT: if (buf[0] != reportnum) return -EINVAL; return __gb_hid_output_raw_report(hid, buf, len, rtype); default: return -EIO; } } /* HID Callbacks */ static int gb_hid_parse(struct hid_device *hid) { struct gb_hid *ghid = hid->driver_data; unsigned int rsize; char *rdesc; int ret; rsize = le16_to_cpu(ghid->hdesc.wReportDescLength); if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { dbg_hid("weird size of report descriptor (%u)\n", rsize); return -EINVAL; } rdesc = kzalloc(rsize, GFP_KERNEL); if (!rdesc) { dbg_hid("couldn't allocate rdesc memory\n"); return -ENOMEM; } ret = gb_hid_get_report_desc(ghid, rdesc); if (ret) { hid_err(hid, "reading report descriptor failed\n"); goto free_rdesc; } ret = hid_parse_report(hid, rdesc, rsize); if (ret) dbg_hid("parsing report descriptor failed\n"); free_rdesc: kfree(rdesc); return ret; } static int gb_hid_start(struct hid_device *hid) { struct gb_hid *ghid = hid->driver_data; unsigned int bufsize = HID_MIN_BUFFER_SIZE; int ret; gb_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); gb_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); gb_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); if (bufsize > HID_MAX_BUFFER_SIZE) bufsize = HID_MAX_BUFFER_SIZE; ret = gb_hid_alloc_buffers(ghid, bufsize); if (ret) return ret; if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS)) gb_hid_init_reports(ghid); return 0; } static void gb_hid_stop(struct hid_device *hid) { struct gb_hid *ghid = hid->driver_data; gb_hid_free_buffers(ghid); } static int gb_hid_open(struct hid_device *hid) { struct gb_hid *ghid = hid->driver_data; int ret; ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON); if (ret < 0) return ret; set_bit(GB_HID_STARTED, &ghid->flags); return 0; } static void gb_hid_close(struct hid_device *hid) { struct gb_hid *ghid = hid->driver_data; int ret; clear_bit(GB_HID_STARTED, &ghid->flags); /* Save some power */ ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF); if (ret) dev_err(&ghid->connection->bundle->dev, "failed to power off (%d)\n", ret); } static int gb_hid_power(struct hid_device *hid, int lvl) { struct gb_hid *ghid = hid->driver_data; switch (lvl) { case PM_HINT_FULLON: return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON); case PM_HINT_NORMAL: return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF); } return 0; } /* HID structure to pass callbacks */ static struct hid_ll_driver gb_hid_ll_driver = { .parse = gb_hid_parse, .start = gb_hid_start, .stop = gb_hid_stop, .open = gb_hid_open, .close = gb_hid_close, .power = gb_hid_power, .raw_request = gb_hid_raw_request, }; static int gb_hid_init(struct gb_hid *ghid) { struct hid_device *hid = ghid->hid; int ret; ret = gb_hid_get_desc(ghid); if (ret) return ret; hid->version = le16_to_cpu(ghid->hdesc.bcdHID); hid->vendor = le16_to_cpu(ghid->hdesc.wVendorID); hid->product = le16_to_cpu(ghid->hdesc.wProductID); hid->country = ghid->hdesc.bCountryCode; hid->driver_data = ghid; hid->ll_driver = &gb_hid_ll_driver; hid->dev.parent = &ghid->connection->bundle->dev; // hid->bus = BUS_GREYBUS; /* Need a bustype for GREYBUS in <linux/input.h> */ /* Set HID device's name */ snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", dev_name(&ghid->connection->bundle->dev), hid->vendor, hid->product); return 0; } static int gb_hid_probe(struct gb_bundle *bundle, const struct greybus_bundle_id *id) { struct greybus_descriptor_cport *cport_desc; struct gb_connection *connection; struct hid_device *hid; struct gb_hid *ghid; int ret; if (bundle->num_cports != 1) return -ENODEV; cport_desc = &bundle->cport_desc[0]; if (cport_desc->protocol_id != GREYBUS_PROTOCOL_HID) return -ENODEV; ghid = kzalloc(sizeof(*ghid), GFP_KERNEL); if (!ghid) return -ENOMEM; connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id), gb_hid_request_handler); if (IS_ERR(connection)) { ret = PTR_ERR(connection); goto err_free_ghid; } gb_connection_set_data(connection, ghid); ghid->connection = connection; hid = hid_allocate_device(); if (IS_ERR(hid)) { ret = PTR_ERR(hid); goto err_connection_destroy; } ghid->hid = hid; ghid->bundle = bundle; greybus_set_drvdata(bundle, ghid); ret = gb_connection_enable(connection); if (ret) goto err_destroy_hid; ret = gb_hid_init(ghid); if (ret) goto err_connection_disable; ret = hid_add_device(hid); if (ret) { hid_err(hid, "can't add hid device: %d\n", ret); goto err_connection_disable; } gb_pm_runtime_put_autosuspend(bundle); return 0; err_connection_disable: gb_connection_disable(connection); err_destroy_hid: hid_destroy_device(hid); err_connection_destroy: gb_connection_destroy(connection); err_free_ghid: kfree(ghid); return ret; } static void gb_hid_disconnect(struct gb_bundle *bundle) { struct gb_hid *ghid = greybus_get_drvdata(bundle); if (gb_pm_runtime_get_sync(bundle)) gb_pm_runtime_get_noresume(bundle); hid_destroy_device(ghid->hid); gb_connection_disable(ghid->connection); gb_connection_destroy(ghid->connection); kfree(ghid); } static const struct greybus_bundle_id gb_hid_id_table[] = { { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_HID) }, { } }; MODULE_DEVICE_TABLE(greybus, gb_hid_id_table); static struct greybus_driver gb_hid_driver = { .name = "hid", .probe = gb_hid_probe, .disconnect = gb_hid_disconnect, .id_table = gb_hid_id_table, }; module_greybus_driver(gb_hid_driver); MODULE_LICENSE("GPL v2");