blob: 04053ff075a67dd72ce90bc415dd7ec1234b68f1 [file] [log] [blame]
// 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");