| // 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 <linux/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 transferred 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) |
| 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 const 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_DESCRIPTION("HID class driver for the Greybus"); |
| MODULE_LICENSE("GPL v2"); |