From 4522643aa9630be17238edf1b4c0b690c5dd7f5d Mon Sep 17 00:00:00 2001 From: Petri Gynther Date: Mon, 24 Mar 2014 13:50:01 -0700 Subject: [PATCH] HID: uhid: Add UHID_CREATE2 + UHID_INPUT2 UHID_CREATE2: HID report descriptor data (rd_data) is an array in struct uhid_create2_req, instead of a pointer. Enables use from languages that don't support pointers, e.g. Python. UHID_INPUT2: Data array is the last field of struct uhid_input2_req. Enables userspace to write only the required bytes to kernel (ev.type + ev.u.input2.size + the part of the data array that matters), instead of the entire struct uhid_input2_req. Note: UHID_CREATE2 increases the total size of struct uhid_event slightly, thus increasing the size of messages that are queued for userspace. However, this won't affect the userspace processing of these events. [Jiri Kosina : adjust to hid_get_raw_report() and hid_output_raw_report() API changes] Signed-off-by: Petri Gynther Reviewed-by: David Herrmann Signed-off-by: Jiri Kosina --- Documentation/hid/uhid.txt | 11 ++++++ drivers/hid/uhid.c | 78 ++++++++++++++++++++++++++++++++++++++ include/uapi/linux/uhid.h | 23 +++++++++++ 3 files changed, 112 insertions(+) diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt index dc35a2b75eee..ee6593608c8e 100644 --- a/Documentation/hid/uhid.txt +++ b/Documentation/hid/uhid.txt @@ -93,6 +93,11 @@ the request was handled successfully. event to the kernel. The payload is of type struct uhid_create_req and contains information about your device. You can start I/O now. + UHID_CREATE2: + Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array + inside struct uhid_create2_req, instead of a pointer to a separate array. + Enables use from languages that don't support pointers, e.g. Python. + UHID_DESTROY: This destroys the internal HID device. No further I/O will be accepted. There may still be pending messages that you can receive with read() but no further @@ -105,6 +110,12 @@ the request was handled successfully. contains a data-payload. This is the raw data that you read from your device. The kernel will parse the HID reports and react on it. + UHID_INPUT2: + Same as UHID_INPUT, but the data array is the last field of uhid_input2_req. + Enables userspace to write only the required bytes to kernel (ev.type + + ev.u.input2.size + the part of the data array that matters), instead of + the entire struct uhid_input2_req. + UHID_FEATURE_ANSWER: If you receive a UHID_FEATURE request you must answer with this request. You must copy the "id" field from the request into the answer. Set the "err" field diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 7ed79be2686a..0d078c32db4f 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -428,6 +428,67 @@ static int uhid_dev_create(struct uhid_device *uhid, return ret; } +static int uhid_dev_create2(struct uhid_device *uhid, + const struct uhid_event *ev) +{ + struct hid_device *hid; + int ret; + + if (uhid->running) + return -EALREADY; + + uhid->rd_size = ev->u.create2.rd_size; + if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE) + return -EINVAL; + + uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL); + if (!uhid->rd_data) + return -ENOMEM; + + memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size); + + hid = hid_allocate_device(); + if (IS_ERR(hid)) { + ret = PTR_ERR(hid); + goto err_free; + } + + strncpy(hid->name, ev->u.create2.name, 127); + hid->name[127] = 0; + strncpy(hid->phys, ev->u.create2.phys, 63); + hid->phys[63] = 0; + strncpy(hid->uniq, ev->u.create2.uniq, 63); + hid->uniq[63] = 0; + + hid->ll_driver = &uhid_hid_driver; + hid->bus = ev->u.create2.bus; + hid->vendor = ev->u.create2.vendor; + hid->product = ev->u.create2.product; + hid->version = ev->u.create2.version; + hid->country = ev->u.create2.country; + hid->driver_data = uhid; + hid->dev.parent = uhid_misc.this_device; + + uhid->hid = hid; + uhid->running = true; + + ret = hid_add_device(hid); + if (ret) { + hid_err(hid, "Cannot register HID device\n"); + goto err_hid; + } + + return 0; + +err_hid: + hid_destroy_device(hid); + uhid->hid = NULL; + uhid->running = false; +err_free: + kfree(uhid->rd_data); + return ret; +} + static int uhid_dev_destroy(struct uhid_device *uhid) { if (!uhid->running) @@ -456,6 +517,17 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) return 0; } +static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) +{ + if (!uhid->running) + return -EINVAL; + + hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, + min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0); + + return 0; +} + static int uhid_dev_feature_answer(struct uhid_device *uhid, struct uhid_event *ev) { @@ -592,12 +664,18 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer, case UHID_CREATE: ret = uhid_dev_create(uhid, &uhid->input_buf); break; + case UHID_CREATE2: + ret = uhid_dev_create2(uhid, &uhid->input_buf); + break; case UHID_DESTROY: ret = uhid_dev_destroy(uhid); break; case UHID_INPUT: ret = uhid_dev_input(uhid, &uhid->input_buf); break; + case UHID_INPUT2: + ret = uhid_dev_input2(uhid, &uhid->input_buf); + break; case UHID_FEATURE_ANSWER: ret = uhid_dev_feature_answer(uhid, &uhid->input_buf); break; diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h index 414b74be4da1..1e3b09c191cd 100644 --- a/include/uapi/linux/uhid.h +++ b/include/uapi/linux/uhid.h @@ -21,6 +21,7 @@ #include #include +#include enum uhid_event_type { UHID_CREATE, @@ -34,6 +35,8 @@ enum uhid_event_type { UHID_INPUT, UHID_FEATURE, UHID_FEATURE_ANSWER, + UHID_CREATE2, + UHID_INPUT2, }; struct uhid_create_req { @@ -50,6 +53,19 @@ struct uhid_create_req { __u32 country; } __attribute__((__packed__)); +struct uhid_create2_req { + __u8 name[128]; + __u8 phys[64]; + __u8 uniq[64]; + __u16 rd_size; + __u16 bus; + __u32 vendor; + __u32 product; + __u32 version; + __u32 country; + __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE]; +} __attribute__((__packed__)); + #define UHID_DATA_MAX 4096 enum uhid_report_type { @@ -63,6 +79,11 @@ struct uhid_input_req { __u16 size; } __attribute__((__packed__)); +struct uhid_input2_req { + __u16 size; + __u8 data[UHID_DATA_MAX]; +} __attribute__((__packed__)); + struct uhid_output_req { __u8 data[UHID_DATA_MAX]; __u16 size; @@ -100,6 +121,8 @@ struct uhid_event { struct uhid_output_ev_req output_ev; struct uhid_feature_req feature; struct uhid_feature_answer_req feature_answer; + struct uhid_create2_req create2; + struct uhid_input2_req input2; } u; } __attribute__((__packed__)); -- GitLab