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/*
* HID class driver for the Greybus.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#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"
/* Version of the Greybus hid protocol we support */
#define GB_HID_VERSION_MAJOR 0x00
#define GB_HID_VERSION_MINOR 0x01
/* Greybus HID request types */
#define GB_HID_TYPE_INVALID 0x00
#define GB_HID_TYPE_PROTOCOL_VERSION 0x01
#define GB_HID_TYPE_GET_DESC 0x02
#define GB_HID_TYPE_GET_REPORT_DESC 0x03
#define GB_HID_TYPE_PWR_ON 0x04
#define GB_HID_TYPE_PWR_OFF 0x05
#define GB_HID_TYPE_GET_REPORT 0x06
#define GB_HID_TYPE_SET_REPORT 0x07
#define GB_HID_TYPE_IRQ_EVENT 0x08
#define GB_HID_TYPE_RESPONSE 0x80 /* OR'd with rest */
/* Report type */
#define GB_HID_INPUT_REPORT 0
#define GB_HID_OUTPUT_REPORT 1
#define GB_HID_FEATURE_REPORT 2
/* Different request/response structures */
/* HID get descriptor response */
struct gb_hid_desc_response {
__u8 bLength;
__le16 wReportDescLength;
__le16 bcdHID;
__le16 wProductID;
__le16 wVendorID;
__u8 bCountryCode;
} __packed;
/* HID get report request/response */
struct gb_hid_get_report_request {
__u8 report_type;
__u8 report_id;
};
/* HID set report request */
struct gb_hid_set_report_request {
__u8 report_type;
__u8 report_id;
__u8 report[0];
};
/* HID input report request, via interrupt pipe */
struct gb_hid_input_report_request {
__u8 report[0];
};
/* Greybus HID device's structure */
struct gb_hid {
struct gb_connection *connection;
u8 version_major;
u8 version_minor;
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;
};
static DEFINE_MUTEX(gb_hid_open_mutex);
/* Routines to get controller's infomation over greybus */
/* Define get_version() routine */
define_get_version(gb_hid, HID);
/* 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)
{
return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT_DESC,
NULL, 0, rdesc,
le16_to_cpu(ghid->hdesc.wReportDescLength));
}
static int gb_hid_set_power(struct gb_hid *ghid, int type)
{
return gb_operation_sync(ghid->connection, type, NULL, 0, NULL, 0);
}
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;
request.report_type = report_type;
request.report_id = report_id;
return gb_operation_sync(ghid->connection, GB_HID_TYPE_GET_REPORT,
&request, sizeof(request), buf, len);
}
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;
operation = gb_operation_create(ghid->connection,
GB_HID_TYPE_SET_REPORT, size, 0);
if (!operation)
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)
pr_err("%s: operation failed (%d)\n", __func__, ret);
else
ret = len;
gb_operation_destroy(operation);
return ret;
}
static void gb_hid_irq_handler(u8 type, struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_hid *ghid = connection->private;
struct gb_hid_input_report_request *request = op->request->payload;
int ret, size;
if (type != GB_HID_TYPE_IRQ_EVENT) {
pr_err("unsupported unsolicited request\n");
return;
}
ret = gb_operation_response_send(op, 0);
if (ret)
pr_err("%s: error %d sending response status %d\n", __func__,
ret, 0);
size = request->report[0] | request->report[1] << 8;
if (!size) {
pr_err("%s: size can't be zero.\n", __func__);
return;
}
if (test_bit(GB_HID_STARTED, &ghid->flags))
hid_input_report(ghid->hid, HID_INPUT_REPORT,
request->report + 2, size - 2, 1);
}
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;
}
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0)
static int gb_hid_get_raw_report(struct hid_device *hid,
unsigned char reportnum, __u8 *buf,
size_t len, unsigned char rtype)
{
return gb_hid_raw_request(hid, reportnum, buf, len, rtype,
HID_REQ_GET_REPORT);
}
static int gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
size_t len, unsigned char rtype)
{
return gb_hid_raw_request(hid, buf[0], buf, len, rtype,
HID_REQ_SET_REPORT);
}
#endif
/* 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 = 0;
mutex_lock(&gb_hid_open_mutex);
if (!hid->open++) {
ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
if (ret < 0)
hid->open--;
else
set_bit(GB_HID_STARTED, &ghid->flags);
}
mutex_unlock(&gb_hid_open_mutex);
return ret;
}
static void gb_hid_close(struct hid_device *hid)
{
struct gb_hid *ghid = hid->driver_data;
/*
* Protecting hid->open to make sure we don't restart data acquistion
* due to a resumption we no longer care about..
*/
mutex_lock(&gb_hid_open_mutex);
if (!--hid->open) {
clear_bit(GB_HID_STARTED, &ghid->flags);
/* Save some power */
WARN_ON(gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF));
}
mutex_unlock(&gb_hid_open_mutex);
}
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,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)
.raw_request = gb_hid_raw_request,
#endif
};
static int gb_hid_init(struct gb_hid *ghid)
{
struct hid_device *hid = ghid->hid;
int ret;
ret = get_version(ghid);
if (ret)
return 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->dev;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0)
hid->hid_get_raw_report = gb_hid_get_raw_report;
hid->hid_output_raw_report = gb_hid_output_raw_report;
#endif
// 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 %04hX:%04hX",
dev_name(&ghid->connection->dev), hid->vendor, hid->product);
return 0;
}
static int gb_hid_connection_init(struct gb_connection *connection)
{
struct hid_device *hid;
struct gb_hid *ghid;
int ret;
ghid = kzalloc(sizeof(*ghid), GFP_KERNEL);
if (!ghid)
return -ENOMEM;
hid = hid_allocate_device();
if (IS_ERR(hid)) {
ret = PTR_ERR(hid);
goto free_ghid;
}
connection->private = ghid;
ghid->connection = connection;
ghid->hid = hid;
ret = gb_hid_init(ghid);
if (ret)
goto destroy_hid;
ret = hid_add_device(hid);
if (!ret)
return 0;
hid_err(hid, "can't add hid device: %d\n", ret);
destroy_hid:
hid_destroy_device(hid);
free_ghid:
kfree(ghid);
return ret;
}
static void gb_hid_connection_exit(struct gb_connection *connection)
{
struct gb_hid *ghid = connection->private;
hid_destroy_device(ghid->hid);
kfree(ghid);
}
static struct gb_protocol hid_protocol = {
.name = "hid",
.id = GREYBUS_PROTOCOL_HID,
.major = 0,
.minor = 1,
.connection_init = gb_hid_connection_init,
.connection_exit = gb_hid_connection_exit,
.request_recv = gb_hid_irq_handler,
};
int gb_hid_protocol_init(void)
{
return gb_protocol_register(&hid_protocol);
}
void gb_hid_protocol_exit(void)
{
gb_protocol_deregister(&hid_protocol);
}
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