/*
* HID over I2C protocol implementation
*
* Copyright (c) 2012 Benjamin Tissoires <[email protected]>
* 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 <[email protected]>
* Copyright (c) 2005 Michael Haboustak <[email protected]> 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/pm_wakeirq.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 <linux/unaligned.h>
#include <drm/drm_panel.h>
#include "../hid-ids.h"
#include "i2c-hid.h"
/* quirks to control the device */
#define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(0)
#define I2C_HID_QUIRK_BOGUS_IRQ BIT(1)
#define I2C_HID_QUIRK_RESET_ON_RESUME BIT(2)
#define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(3)
#define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(4)
#define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND BIT(5)
/* 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_PWR_ON 0x00
#define I2C_HID_PWR_SLEEP 0x01
#define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
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 */
struct mutex cmd_lock; /* protects cmdbuf and rawbuf */
struct mutex reset_lock;
struct i2chid_ops *ops;
struct drm_panel_follower panel_follower;
struct work_struct panel_follower_prepare_work;
bool is_panel_follower;
bool prepare_work_finished;
};
static const struct i2c_hid_quirks {
__u16 idVendor;
__u16 idProduct;
__u32 quirks;
} i2c_hid_quirks[] = {
{ 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 },
{ I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
/*
* 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_probe_address(struct i2c_hid *ihid)
{
int ret;
/*
* Some STM-based devices need 400µs after a rising clock edge to wake
* from deep sleep, in which case the first read will fail. Try after a
* short sleep to see if the device came alive on the bus. Certain
* Weida Tech devices also need this.
*/
ret = i2c_smbus_read_byte(ihid->client);
if (ret < 0) {
usleep_range(400, 500);
ret = i2c_smbus_read_byte(ihid->client);
}
return ret < 0 ? ret : 0;
}
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++;
}
ret = i2c_transfer(client->adapter, msgs, n);
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)
{
guard(mutex)(&ihid->cmd_lock);
*(__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__);
guard(mutex)(&ihid->cmd_lock);
/* 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;
guard(mutex)(&ihid->cmd_lock);
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;
guard(mutex)(&ihid->cmd_lock);
/* 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__);
ret = i2c_hid_set_power_command(ihid, power_state);
if (ret)
dev_err(&ihid->client->dev,
"failed to change power setting.\n");
/*
* 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_start_hwreset(struct i2c_hid *ihid)
{
size_t length = 0;
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.
*/
lockdep_assert_held(&ihid->reset_lock);
ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
if (ret)
return ret;
scoped_guard(mutex, &ihid->cmd_lock) {
/* 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: %d\n", ret);
break;
}
return 0;
}
/* Clean up if sending reset command failed */
clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
return ret;
}
static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
{
int ret = 0;
i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
msleep(100);
clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
} else if (!wait_event_timeout(ihid->wait,
!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
msecs_to_jiffies(1000))) {
dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
}
i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
/* 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);
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;
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;
char *rdesc = NULL, *use_override = NULL;
unsigned int rsize;
int ret;
int tries = 3;
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;
}
mutex_lock(&ihid->reset_lock);
do {
ret = i2c_hid_start_hwreset(ihid);
if (ret == 0)
ret = i2c_hid_finish_hwreset(ihid);
else
msleep(1000);
} while (tries-- > 0 && ret);
mutex_unlock(&ihid->reset_lock);
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)
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");
goto out;
}
}
i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
ret = hid_parse_report(hid, rdesc, rsize);
if (ret)
dbg_hid("parsing report descriptor failed\n");
out:
if (!use_override)
kfree(rdesc);
return ret;
}
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);
}
static const 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,
};
static int i2c_hid_init_irq(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
unsigned long irqflags = 0;
int ret;
i2c_hid_dbg(ihid, "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 | IRQF_NO_AUTOEN,
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);
}
static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
{
struct i2c_client *client = ihid->client;
struct hid_device *hid = ihid->hid;
int ret;
ret = hid_driver_suspend(hid, PMSG_SUSPEND);
if (ret < 0)
return ret;
/* Save some power */
if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
disable_irq(client->irq);
if (force_poweroff || !device_may_wakeup(&client->dev))
i2c_hid_core_power_down(ihid);
return 0;
}
static int i2c_hid_core_resume(struct i2c_hid *ihid)
{
struct i2c_client *client = ihid->client;
struct hid_device *hid = ihid->hid;
int ret;
if (!device_may_wakeup(&client->dev))
i2c_hid_core_power_up(ihid);
enable_irq(client->irq);
/* Make sure the device is awake on the bus */
ret = i2c_hid_probe_address(ihid);
if (ret < 0) {
dev_err(&client->dev, "nothing at address after resume: %d\n",
ret);
return -ENXIO;
}
/* 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) {
mutex_lock(&ihid->reset_lock);
ret = i2c_hid_start_hwreset(ihid);
if (ret == 0)
ret = i2c_hid_finish_hwreset(ihid);
mutex_unlock(&ihid->reset_lock);
} else {
ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
}
if (ret)
return ret;
return hid_driver_reset_resume(hid);
}
/*
* Check that the device exists and parse the HID descriptor.
*/
static int __i2c_hid_core_probe(struct i2c_hid *ihid)
{
struct i2c_client *client = ihid->client;
struct hid_device *hid = ihid->hid;
int ret;
ret = i2c_hid_probe_address(ihid);
if (ret < 0) {
i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
return -ENXIO;
}
ret = i2c_hid_fetch_hid_descriptor(ihid);
if (ret < 0) {
dev_err(&client->dev,
"Failed to fetch the HID Descriptor\n");
return ret;
}
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 |= 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);
return 0;
}
static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
{
struct i2c_client *client = ihid->client;
struct hid_device *hid = ihid->hid;
int ret;
enable_irq(client->irq);
ret = hid_add_device(hid);
if (ret) {
if (ret != -ENODEV)
hid_err(client, "can't add hid device: %d\n", ret);
disable_irq(client->irq);
return ret;
}
return 0;
}
static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
{
int ret;
ret = i2c_hid_core_power_up(ihid);
if (ret)
return ret;
ret = __i2c_hid_core_probe(ihid);
if (ret)
goto err_power_down;
ret = i2c_hid_core_register_hid(ihid);
if (ret)
goto err_power_down;
return 0;
err_power_down:
i2c_hid_core_power_down(ihid);
return ret;
}
static void ihid_core_panel_prepare_work(struct work_struct *work)
{
struct i2c_hid *ihid = container_of(work, struct i2c_hid,
panel_follower_prepare_work);
struct hid_device *hid = ihid->hid;
int ret;
/*
* hid->version is set on the first power up. If it's still zero then
* this is the first power on so we should perform initial power up
* steps.
*/
if (!hid->version)
ret = i2c_hid_core_probe_panel_follower(ihid);
else
ret = i2c_hid_core_resume(ihid);
if (ret)
dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
else
WRITE_ONCE(ihid->prepare_work_finished, true);
/*
* The work APIs provide a number of memory ordering guarantees
* including one that says that memory writes before schedule_work()
* are always visible to the work function, but they don't appear to
* guarantee that a write that happened in the work is visible after
* cancel_work_sync(). We'll add a write memory barrier here to match
* with i2c_hid_core_panel_unpreparing() to ensure that our write to
* prepare_work_finished is visible there.
*/
smp_wmb();
}
static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
{
struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
/*
* Powering on a touchscreen can be a slow process. Queue the work to
* the system workqueue so we don't block the panel's power up.
*/
WRITE_ONCE(ihid->prepare_work_finished, false);
schedule_work(&ihid->panel_follower_prepare_work);
return 0;
}
static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
{
struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
cancel_work_sync(&ihid->panel_follower_prepare_work);
/* Match with ihid_core_panel_prepare_work() */
smp_rmb();
if (!READ_ONCE(ihid->prepare_work_finished))
return 0;
return i2c_hid_core_suspend(ihid, true);
}
static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
.panel_prepared = i2c_hid_core_panel_prepared,
.panel_unpreparing = i2c_hid_core_panel_unpreparing,
};
static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
{
struct device *dev = &ihid->client->dev;
int ret;
ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
/*
* If we're not in control of our own power up/power down then we can't
* do the logic to manage wakeups. Give a warning if a user thought
* that was possible then force the capability off.
*/
if (device_can_wakeup(dev)) {
dev_warn(dev, "Can't wakeup if following panel\n");
device_set_wakeup_capable(dev, false);
}
ret = drm_panel_add_follower(dev, &ihid->panel_follower);
if (ret)
return ret;
return 0;
}
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;
i2c_set_clientdata(client, ihid);
ihid->ops = ops;
ihid->client = client;
ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
init_waitqueue_head(&ihid->wait);
mutex_init(&ihid->cmd_lock);
mutex_init(&ihid->reset_lock);
INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
/* 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)
return ret;
device_enable_async_suspend(&client->dev);
hid = hid_allocate_device();
if (IS_ERR(hid)) {
ret = PTR_ERR(hid);
goto err_free_buffers;
}
ihid->hid = hid;
hid->driver_data = client;
hid->ll_driver = &i2c_hid_ll_driver;
hid->dev.parent = &client->dev;
hid->bus = BUS_I2C;
hid->initial_quirks = quirks;
/* Power on and probe unless device is a panel follower. */
if (!ihid->is_panel_follower) {
ret = i2c_hid_core_power_up(ihid);
if (ret < 0)
goto err_destroy_device;
ret = __i2c_hid_core_probe(ihid);
if (ret < 0)
goto err_power_down;
}
ret = i2c_hid_init_irq(client);
if (ret < 0)
goto err_power_down;
/*
* If we're a panel follower, we'll register when the panel turns on;
* otherwise we do it right away.
*/
if (ihid->is_panel_follower)
ret = i2c_hid_core_register_panel_follower(ihid);
else
ret = i2c_hid_core_register_hid(ihid);
if (ret)
goto err_free_irq;
return 0;
err_free_irq:
free_irq(client->irq, ihid);
err_power_down:
if (!ihid->is_panel_follower)
i2c_hid_core_power_down(ihid);
err_destroy_device:
hid_destroy_device(hid);
err_free_buffers:
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;
/*
* If we're a follower, the act of unfollowing will cause us to be
* powered down. Otherwise we need to manually do it.
*/
if (ihid->is_panel_follower)
drm_panel_remove_follower(&ihid->panel_follower);
else
i2c_hid_core_suspend(ihid, true);
hid = ihid->hid;
hid_destroy_device(hid);
free_irq(client->irq, ihid);
if (ihid->bufsize)
i2c_hid_free_buffers(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);
static int i2c_hid_core_pm_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_hid *ihid = i2c_get_clientdata(client);
if (ihid->is_panel_follower)
return 0;
return i2c_hid_core_suspend(ihid, false);
}
static int i2c_hid_core_pm_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_hid *ihid = i2c_get_clientdata(client);
if (ihid->is_panel_follower)
return 0;
return i2c_hid_core_resume(ihid);
}
const struct dev_pm_ops i2c_hid_core_pm = {
SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
};
EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
MODULE_DESCRIPTION("HID over I2C core driver");
MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
MODULE_LICENSE("GPL");
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