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linuxdebug/drivers/hid/i2c-hid/i2c-hid-core.c

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/*
* HID over I2C protocol implementation
*
* Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
* Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
* Copyright (c) 2012 Red Hat, Inc
*
* This code is partly based on "USB HID support for Linux":
*
* Copyright (c) 1999 Andreas Gal
* Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
* Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
* Copyright (c) 2007-2008 Oliver Neukum
* Copyright (c) 2006-2010 Jiri Kosina
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <asm/unaligned.h>
#include "../hid-ids.h"
#include "i2c-hid.h"
/* quirks to control the device */
#define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0)
#define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1)
#define I2C_HID_QUIRK_BOGUS_IRQ BIT(4)
#define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5)
#define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6)
#define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(7)
/* Command opcodes */
#define I2C_HID_OPCODE_RESET 0x01
#define I2C_HID_OPCODE_GET_REPORT 0x02
#define I2C_HID_OPCODE_SET_REPORT 0x03
#define I2C_HID_OPCODE_GET_IDLE 0x04
#define I2C_HID_OPCODE_SET_IDLE 0x05
#define I2C_HID_OPCODE_GET_PROTOCOL 0x06
#define I2C_HID_OPCODE_SET_PROTOCOL 0x07
#define I2C_HID_OPCODE_SET_POWER 0x08
/* flags */
#define I2C_HID_STARTED 0
#define I2C_HID_RESET_PENDING 1
#define I2C_HID_READ_PENDING 2
#define I2C_HID_PWR_ON 0x00
#define I2C_HID_PWR_SLEEP 0x01
/* debug option */
static bool debug;
module_param(debug, bool, 0444);
MODULE_PARM_DESC(debug, "print a lot of debug information");
#define i2c_hid_dbg(ihid, fmt, arg...) \
do { \
if (debug) \
dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
} while (0)
struct i2c_hid_desc {
__le16 wHIDDescLength;
__le16 bcdVersion;
__le16 wReportDescLength;
__le16 wReportDescRegister;
__le16 wInputRegister;
__le16 wMaxInputLength;
__le16 wOutputRegister;
__le16 wMaxOutputLength;
__le16 wCommandRegister;
__le16 wDataRegister;
__le16 wVendorID;
__le16 wProductID;
__le16 wVersionID;
__le32 reserved;
} __packed;
/* The main device structure */
struct i2c_hid {
struct i2c_client *client; /* i2c client */
struct hid_device *hid; /* pointer to corresponding HID dev */
struct i2c_hid_desc hdesc; /* the HID Descriptor */
__le16 wHIDDescRegister; /* location of the i2c
* register of the HID
* descriptor. */
unsigned int bufsize; /* i2c buffer size */
u8 *inbuf; /* Input buffer */
u8 *rawbuf; /* Raw Input buffer */
u8 *cmdbuf; /* Command buffer */
unsigned long flags; /* device flags */
unsigned long quirks; /* Various quirks */
wait_queue_head_t wait; /* For waiting the interrupt */
bool irq_wake_enabled;
struct mutex reset_lock;
struct i2chid_ops *ops;
};
static const struct i2c_hid_quirks {
__u16 idVendor;
__u16 idProduct;
__u32 quirks;
} i2c_hid_quirks[] = {
{ USB_VENDOR_ID_WEIDA, HID_ANY_ID,
I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
I2C_HID_QUIRK_RESET_ON_RESUME },
{ I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
I2C_HID_QUIRK_RESET_ON_RESUME },
{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
I2C_HID_QUIRK_BAD_INPUT_SIZE },
/*
* Sending the wakeup after reset actually break ELAN touchscreen controller
*/
{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
I2C_HID_QUIRK_BOGUS_IRQ },
{ 0, 0 }
};
/*
* i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
* @idVendor: the 16-bit vendor ID
* @idProduct: the 16-bit product ID
*
* Returns: a u32 quirks value.
*/
static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
{
u32 quirks = 0;
int n;
for (n = 0; i2c_hid_quirks[n].idVendor; n++)
if (i2c_hid_quirks[n].idVendor == idVendor &&
(i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
i2c_hid_quirks[n].idProduct == idProduct))
quirks = i2c_hid_quirks[n].quirks;
return quirks;
}
static int i2c_hid_xfer(struct i2c_hid *ihid,
u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
{
struct i2c_client *client = ihid->client;
struct i2c_msg msgs[2] = { 0 };
int n = 0;
int ret;
if (send_len) {
i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
__func__, send_len, send_buf);
msgs[n].addr = client->addr;
msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
msgs[n].len = send_len;
msgs[n].buf = send_buf;
n++;
}
if (recv_len) {
msgs[n].addr = client->addr;
msgs[n].flags = (client->flags & I2C_M_TEN) |
I2C_M_RD | I2C_M_DMA_SAFE;
msgs[n].len = recv_len;
msgs[n].buf = recv_buf;
n++;
set_bit(I2C_HID_READ_PENDING, &ihid->flags);
}
ret = i2c_transfer(client->adapter, msgs, n);
if (recv_len)
clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
if (ret != n)
return ret < 0 ? ret : -EIO;
return 0;
}
static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
void *buf, size_t len)
{
*(__le16 *)ihid->cmdbuf = reg;
return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
}
static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
int report_type, int report_id)
{
size_t length = 0;
if (report_id < 0x0F) {
buf[length++] = report_type << 4 | report_id;
buf[length++] = opcode;
} else {
buf[length++] = report_type << 4 | 0x0F;
buf[length++] = opcode;
buf[length++] = report_id;
}
return length;
}
static int i2c_hid_get_report(struct i2c_hid *ihid,
u8 report_type, u8 report_id,
u8 *recv_buf, size_t recv_len)
{
size_t length = 0;
size_t ret_count;
int error;
i2c_hid_dbg(ihid, "%s\n", __func__);
/* Command register goes first */
*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
length += sizeof(__le16);
/* Next is GET_REPORT command */
length += i2c_hid_encode_command(ihid->cmdbuf + length,
I2C_HID_OPCODE_GET_REPORT,
report_type, report_id);
/*
* Device will send report data through data register. Because
* command can be either 2 or 3 bytes destination for the data
* register may be not aligned.
*/
put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
ihid->cmdbuf + length);
length += sizeof(__le16);
/*
* In addition to report data device will supply data length
* in the first 2 bytes of the response, so adjust .
*/
error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
ihid->rawbuf, recv_len + sizeof(__le16));
if (error) {
dev_err(&ihid->client->dev,
"failed to set a report to device: %d\n", error);
return error;
}
/* The buffer is sufficiently aligned */
ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
/* Check for empty report response */
if (ret_count <= sizeof(__le16))
return 0;
recv_len = min(recv_len, ret_count - sizeof(__le16));
memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
dev_err(&ihid->client->dev,
"device returned incorrect report (%d vs %d expected)\n",
recv_buf[0], report_id);
return -EINVAL;
}
return recv_len;
}
static size_t i2c_hid_format_report(u8 *buf, int report_id,
const u8 *data, size_t size)
{
size_t length = sizeof(__le16); /* reserve space to store size */
if (report_id)
buf[length++] = report_id;
memcpy(buf + length, data, size);
length += size;
/* Store overall size in the beginning of the buffer */
put_unaligned_le16(length, buf);
return length;
}
/**
* i2c_hid_set_or_send_report: forward an incoming report to the device
* @ihid: the i2c hid device
* @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
* @report_id: the report ID
* @buf: the actual data to transfer, without the report ID
* @data_len: size of buf
* @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
*/
static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
u8 report_type, u8 report_id,
const u8 *buf, size_t data_len,
bool do_set)
{
size_t length = 0;
int error;
i2c_hid_dbg(ihid, "%s\n", __func__);
if (data_len > ihid->bufsize)
return -EINVAL;
if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
return -ENOSYS;
if (do_set) {
/* Command register goes first */
*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
length += sizeof(__le16);
/* Next is SET_REPORT command */
length += i2c_hid_encode_command(ihid->cmdbuf + length,
I2C_HID_OPCODE_SET_REPORT,
report_type, report_id);
/*
* Report data will go into the data register. Because
* command can be either 2 or 3 bytes destination for
* the data register may be not aligned.
*/
put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
ihid->cmdbuf + length);
length += sizeof(__le16);
} else {
/*
* With simple "send report" all data goes into the output
* register.
*/
*(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
length += sizeof(__le16);
}
length += i2c_hid_format_report(ihid->cmdbuf + length,
report_id, buf, data_len);
error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
if (error) {
dev_err(&ihid->client->dev,
"failed to set a report to device: %d\n", error);
return error;
}
return data_len;
}
static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
{
size_t length;
/* SET_POWER uses command register */
*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
length = sizeof(__le16);
/* Now the command itself */
length += i2c_hid_encode_command(ihid->cmdbuf + length,
I2C_HID_OPCODE_SET_POWER,
0, power_state);
return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
}
static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
{
int ret;
i2c_hid_dbg(ihid, "%s\n", __func__);
/*
* Some devices require to send a command to wakeup before power on.
* The call will get a return value (EREMOTEIO) but device will be
* triggered and activated. After that, it goes like a normal device.
*/
if (power_state == I2C_HID_PWR_ON &&
ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
/* Device was already activated */
if (!ret)
goto set_pwr_exit;
}
ret = i2c_hid_set_power_command(ihid, power_state);
if (ret)
dev_err(&ihid->client->dev,
"failed to change power setting.\n");
set_pwr_exit:
/*
* The HID over I2C specification states that if a DEVICE needs time
* after the PWR_ON request, it should utilise CLOCK stretching.
* However, it has been observered that the Windows driver provides a
* 1ms sleep between the PWR_ON and RESET requests.
* According to Goodix Windows even waits 60 ms after (other?)
* PWR_ON requests. Testing has confirmed that several devices
* will not work properly without a delay after a PWR_ON request.
*/
if (!ret && power_state == I2C_HID_PWR_ON)
msleep(60);
return ret;
}
static int i2c_hid_execute_reset(struct i2c_hid *ihid)
{
size_t length = 0;
int ret;
i2c_hid_dbg(ihid, "resetting...\n");
/* Prepare reset command. Command register goes first. */
*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
length += sizeof(__le16);
/* Next is RESET command itself */
length += i2c_hid_encode_command(ihid->cmdbuf + length,
I2C_HID_OPCODE_RESET, 0, 0);
set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
if (ret) {
dev_err(&ihid->client->dev, "failed to reset device.\n");
goto out;
}
if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
msleep(100);
goto out;
}
i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
if (!wait_event_timeout(ihid->wait,
!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
msecs_to_jiffies(5000))) {
ret = -ENODATA;
goto out;
}
i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
out:
clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
return ret;
}
static int i2c_hid_hwreset(struct i2c_hid *ihid)
{
int ret;
i2c_hid_dbg(ihid, "%s\n", __func__);
/*
* This prevents sending feature reports while the device is
* being reset. Otherwise we may lose the reset complete
* interrupt.
*/
mutex_lock(&ihid->reset_lock);
ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
if (ret)
goto out_unlock;
ret = i2c_hid_execute_reset(ihid);
if (ret) {
dev_err(&ihid->client->dev,
"failed to reset device: %d\n", ret);
i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
goto out_unlock;
}
/* At least some SIS devices need this after reset */
if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
out_unlock:
mutex_unlock(&ihid->reset_lock);
return ret;
}
static void i2c_hid_get_input(struct i2c_hid *ihid)
{
u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
u16 ret_size;
int ret;
if (size > ihid->bufsize)
size = ihid->bufsize;
ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
if (ret != size) {
if (ret < 0)
return;
dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
__func__, ret, size);
return;
}
/* Receiving buffer is properly aligned */
ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
if (!ret_size) {
/* host or device initiated RESET completed */
if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
wake_up(&ihid->wait);
return;
}
if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
dev_warn_once(&ihid->client->dev,
"%s: IRQ triggered but there's no data\n",
__func__);
return;
}
if (ret_size > size || ret_size < sizeof(__le16)) {
if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
*(__le16 *)ihid->inbuf = cpu_to_le16(size);
ret_size = size;
} else {
dev_err(&ihid->client->dev,
"%s: incomplete report (%d/%d)\n",
__func__, size, ret_size);
return;
}
}
i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
if (ihid->hid->group != HID_GROUP_RMI)
pm_wakeup_event(&ihid->client->dev, 0);
hid_input_report(ihid->hid, HID_INPUT_REPORT,
ihid->inbuf + sizeof(__le16),
ret_size - sizeof(__le16), 1);
}
return;
}
static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
{
struct i2c_hid *ihid = dev_id;
if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
return IRQ_HANDLED;
i2c_hid_get_input(ihid);
return IRQ_HANDLED;
}
static int i2c_hid_get_report_length(struct hid_report *report)
{
return ((report->size - 1) >> 3) + 1 +
report->device->report_enum[report->type].numbered + 2;
}
/*
* Traverse the supplied list of reports and find the longest
*/
static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
unsigned int *max)
{
struct hid_report *report;
unsigned int size;
/* We should not rely on wMaxInputLength, as some devices may set it to
* a wrong length. */
list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
size = i2c_hid_get_report_length(report);
if (*max < size)
*max = size;
}
}
static void i2c_hid_free_buffers(struct i2c_hid *ihid)
{
kfree(ihid->inbuf);
kfree(ihid->rawbuf);
kfree(ihid->cmdbuf);
ihid->inbuf = NULL;
ihid->rawbuf = NULL;
ihid->cmdbuf = NULL;
ihid->bufsize = 0;
}
static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
{
/*
* The worst case is computed from the set_report command with a
* reportID > 15 and the maximum report length.
*/
int cmd_len = sizeof(__le16) + /* command register */
sizeof(u8) + /* encoded report type/ID */
sizeof(u8) + /* opcode */
sizeof(u8) + /* optional 3rd byte report ID */
sizeof(__le16) + /* data register */
sizeof(__le16) + /* report data size */
sizeof(u8) + /* report ID if numbered report */
report_size;
ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
i2c_hid_free_buffers(ihid);
return -ENOMEM;
}
ihid->bufsize = report_size;
return 0;
}
static int i2c_hid_get_raw_report(struct hid_device *hid,
u8 report_type, u8 report_id,
u8 *buf, size_t count)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret_count;
if (report_type == HID_OUTPUT_REPORT)
return -EINVAL;
/*
* In case of unnumbered reports the response from the device will
* not have the report ID that the upper layers expect, so we need
* to stash it the buffer ourselves and adjust the data size.
*/
if (!report_id) {
buf[0] = 0;
buf++;
count--;
}
ret_count = i2c_hid_get_report(ihid,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
report_id, buf, count);
if (ret_count > 0 && !report_id)
ret_count++;
return ret_count;
}
static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
const u8 *buf, size_t count, bool do_set)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int report_id = buf[0];
int ret;
if (report_type == HID_INPUT_REPORT)
return -EINVAL;
mutex_lock(&ihid->reset_lock);
/*
* Note that both numbered and unnumbered reports passed here
* are supposed to have report ID stored in the 1st byte of the
* buffer, so we strip it off unconditionally before passing payload
* to i2c_hid_set_or_send_report which takes care of encoding
* everything properly.
*/
ret = i2c_hid_set_or_send_report(ihid,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
report_id, buf + 1, count - 1, do_set);
if (ret >= 0)
ret++; /* add report_id to the number of transferred bytes */
mutex_unlock(&ihid->reset_lock);
return ret;
}
static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
{
return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
false);
}
static int i2c_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 i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
case HID_REQ_SET_REPORT:
if (buf[0] != reportnum)
return -EINVAL;
return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
default:
return -EIO;
}
}
static int i2c_hid_parse(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct i2c_hid_desc *hdesc = &ihid->hdesc;
unsigned int rsize;
char *rdesc;
int ret;
int tries = 3;
char *use_override;
i2c_hid_dbg(ihid, "entering %s\n", __func__);
rsize = le16_to_cpu(hdesc->wReportDescLength);
if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
dbg_hid("weird size of report descriptor (%u)\n", rsize);
return -EINVAL;
}
do {
ret = i2c_hid_hwreset(ihid);
if (ret)
msleep(1000);
} while (tries-- > 0 && ret);
if (ret)
return ret;
use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
&rsize);
if (use_override) {
rdesc = use_override;
i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
} else {
rdesc = kzalloc(rsize, GFP_KERNEL);
if (!rdesc) {
dbg_hid("couldn't allocate rdesc memory\n");
return -ENOMEM;
}
i2c_hid_dbg(ihid, "asking HID report descriptor\n");
ret = i2c_hid_read_register(ihid,
ihid->hdesc.wReportDescRegister,
rdesc, rsize);
if (ret) {
hid_err(hid, "reading report descriptor failed\n");
kfree(rdesc);
return -EIO;
}
}
i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
ret = hid_parse_report(hid, rdesc, rsize);
if (!use_override)
kfree(rdesc);
if (ret) {
dbg_hid("parsing report descriptor failed\n");
return ret;
}
return 0;
}
static int i2c_hid_start(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
unsigned int bufsize = HID_MIN_BUFFER_SIZE;
i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
if (bufsize > ihid->bufsize) {
disable_irq(client->irq);
i2c_hid_free_buffers(ihid);
ret = i2c_hid_alloc_buffers(ihid, bufsize);
enable_irq(client->irq);
if (ret)
return ret;
}
return 0;
}
static void i2c_hid_stop(struct hid_device *hid)
{
hid->claimed = 0;
}
static int i2c_hid_open(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
set_bit(I2C_HID_STARTED, &ihid->flags);
return 0;
}
static void i2c_hid_close(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
clear_bit(I2C_HID_STARTED, &ihid->flags);
}
struct hid_ll_driver i2c_hid_ll_driver = {
.parse = i2c_hid_parse,
.start = i2c_hid_start,
.stop = i2c_hid_stop,
.open = i2c_hid_open,
.close = i2c_hid_close,
.output_report = i2c_hid_output_report,
.raw_request = i2c_hid_raw_request,
};
EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
static int i2c_hid_init_irq(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
unsigned long irqflags = 0;
int ret;
dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
if (!irq_get_trigger_type(client->irq))
irqflags = IRQF_TRIGGER_LOW;
ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
irqflags | IRQF_ONESHOT, client->name, ihid);
if (ret < 0) {
dev_warn(&client->dev,
"Could not register for %s interrupt, irq = %d,"
" ret = %d\n",
client->name, client->irq, ret);
return ret;
}
return 0;
}
static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
{
struct i2c_client *client = ihid->client;
struct i2c_hid_desc *hdesc = &ihid->hdesc;
unsigned int dsize;
int error;
/* i2c hid fetch using a fixed descriptor size (30 bytes) */
if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
ihid->hdesc =
*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
} else {
i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
error = i2c_hid_read_register(ihid,
ihid->wHIDDescRegister,
&ihid->hdesc,
sizeof(ihid->hdesc));
if (error) {
dev_err(&ihid->client->dev,
"failed to fetch HID descriptor: %d\n",
error);
return -ENODEV;
}
}
/* Validate the length of HID descriptor, the 4 first bytes:
* bytes 0-1 -> length
* bytes 2-3 -> bcdVersion (has to be 1.00) */
/* check bcdVersion == 1.0 */
if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
dev_err(&ihid->client->dev,
"unexpected HID descriptor bcdVersion (0x%04hx)\n",
le16_to_cpu(hdesc->bcdVersion));
return -ENODEV;
}
/* Descriptor length should be 30 bytes as per the specification */
dsize = le16_to_cpu(hdesc->wHIDDescLength);
if (dsize != sizeof(struct i2c_hid_desc)) {
dev_err(&ihid->client->dev,
"weird size of HID descriptor (%u)\n", dsize);
return -ENODEV;
}
i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
return 0;
}
static int i2c_hid_core_power_up(struct i2c_hid *ihid)
{
if (!ihid->ops->power_up)
return 0;
return ihid->ops->power_up(ihid->ops);
}
static void i2c_hid_core_power_down(struct i2c_hid *ihid)
{
if (!ihid->ops->power_down)
return;
ihid->ops->power_down(ihid->ops);
}
static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
{
if (!ihid->ops->shutdown_tail)
return;
ihid->ops->shutdown_tail(ihid->ops);
}
int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
u16 hid_descriptor_address, u32 quirks)
{
int ret;
struct i2c_hid *ihid;
struct hid_device *hid;
dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
if (!client->irq) {
dev_err(&client->dev,
"HID over i2c has not been provided an Int IRQ\n");
return -EINVAL;
}
if (client->irq < 0) {
if (client->irq != -EPROBE_DEFER)
dev_err(&client->dev,
"HID over i2c doesn't have a valid IRQ\n");
return client->irq;
}
ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
if (!ihid)
return -ENOMEM;
ihid->ops = ops;
ret = i2c_hid_core_power_up(ihid);
if (ret)
return ret;
i2c_set_clientdata(client, ihid);
ihid->client = client;
ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
init_waitqueue_head(&ihid->wait);
mutex_init(&ihid->reset_lock);
/* we need to allocate the command buffer without knowing the maximum
* size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
* real computation later. */
ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
if (ret < 0)
goto err_powered;
device_enable_async_suspend(&client->dev);
/* Make sure there is something at this address */
ret = i2c_smbus_read_byte(client);
if (ret < 0) {
dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
ret = -ENXIO;
goto err_powered;
}
ret = i2c_hid_fetch_hid_descriptor(ihid);
if (ret < 0) {
dev_err(&client->dev,
"Failed to fetch the HID Descriptor\n");
goto err_powered;
}
ret = i2c_hid_init_irq(client);
if (ret < 0)
goto err_powered;
hid = hid_allocate_device();
if (IS_ERR(hid)) {
ret = PTR_ERR(hid);
goto err_irq;
}
ihid->hid = hid;
hid->driver_data = client;
hid->ll_driver = &i2c_hid_ll_driver;
hid->dev.parent = &client->dev;
hid->bus = BUS_I2C;
hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
hid->product = le16_to_cpu(ihid->hdesc.wProductID);
hid->initial_quirks = quirks;
hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
hid->product);
snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
client->name, (u16)hid->vendor, (u16)hid->product);
strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
ret = hid_add_device(hid);
if (ret) {
if (ret != -ENODEV)
hid_err(client, "can't add hid device: %d\n", ret);
goto err_mem_free;
}
return 0;
err_mem_free:
hid_destroy_device(hid);
err_irq:
free_irq(client->irq, ihid);
err_powered:
i2c_hid_core_power_down(ihid);
i2c_hid_free_buffers(ihid);
return ret;
}
EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
void i2c_hid_core_remove(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct hid_device *hid;
hid = ihid->hid;
hid_destroy_device(hid);
free_irq(client->irq, ihid);
if (ihid->bufsize)
i2c_hid_free_buffers(ihid);
i2c_hid_core_power_down(ihid);
}
EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
void i2c_hid_core_shutdown(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
free_irq(client->irq, ihid);
i2c_hid_core_shutdown_tail(ihid);
}
EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
#ifdef CONFIG_PM_SLEEP
static int i2c_hid_core_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct hid_device *hid = ihid->hid;
int ret;
int wake_status;
ret = hid_driver_suspend(hid, PMSG_SUSPEND);
if (ret < 0)
return ret;
/* Save some power */
i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
disable_irq(client->irq);
if (device_may_wakeup(&client->dev)) {
wake_status = enable_irq_wake(client->irq);
if (!wake_status)
ihid->irq_wake_enabled = true;
else
hid_warn(hid, "Failed to enable irq wake: %d\n",
wake_status);
} else {
i2c_hid_core_power_down(ihid);
}
return 0;
}
static int i2c_hid_core_resume(struct device *dev)
{
int ret;
struct i2c_client *client = to_i2c_client(dev);
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct hid_device *hid = ihid->hid;
int wake_status;
if (!device_may_wakeup(&client->dev)) {
i2c_hid_core_power_up(ihid);
} else if (ihid->irq_wake_enabled) {
wake_status = disable_irq_wake(client->irq);
if (!wake_status)
ihid->irq_wake_enabled = false;
else
hid_warn(hid, "Failed to disable irq wake: %d\n",
wake_status);
}
enable_irq(client->irq);
/* Instead of resetting device, simply powers the device on. This
* solves "incomplete reports" on Raydium devices 2386:3118 and
* 2386:4B33 and fixes various SIS touchscreens no longer sending
* data after a suspend/resume.
*
* However some ALPS touchpads generate IRQ storm without reset, so
* let's still reset them here.
*/
if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
ret = i2c_hid_hwreset(ihid);
else
ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
if (ret)
return ret;
return hid_driver_reset_resume(hid);
}
#endif
const struct dev_pm_ops i2c_hid_core_pm = {
SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
};
EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
MODULE_DESCRIPTION("HID over I2C core driver");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_LICENSE("GPL");
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