Commit 8eb92e5c authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Dmitry Torokhov
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Input: psmouse - add support for SMBus companions



This provides glue between PS/2 devices that enumerate the RMI4 devices
and Elan touchpads to the RMI4 (or Elan) SMBus driver.

The SMBus devices keep their PS/2 connection alive. If the initialization
process goes too far (psmouse_activate called), the device disconnects
from the I2C bus and stays on the PS/2 bus, that is why we explicitly
disable PS/2 device reporting (by calling psmouse_deactivate) before
trying to register SMBus companion device.

The HID over I2C devices are enumerated through the ACPI DSDT, and
their PS/2 device also exports the InterTouch bit in the extended
capability 0x0C. However, the firmware keeps its I2C connection open
even after going further in the PS/2 initialization. We don't need
to take extra precautions with those device, especially because they
block their PS/2 communication when HID over I2C is used.
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent c774326a
......@@ -171,6 +171,10 @@ config MOUSE_PS2_VMMOUSE
If unsure, say N.
config MOUSE_PS2_SMBUS
bool
depends on MOUSE_PS2
config MOUSE_SERIAL
tristate "Serial mouse"
select SERIO
......
......@@ -39,6 +39,8 @@ psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT) += touchkit_ps2.o
psmouse-$(CONFIG_MOUSE_PS2_CYPRESS) += cypress_ps2.o
psmouse-$(CONFIG_MOUSE_PS2_VMMOUSE) += vmmouse.o
psmouse-$(CONFIG_MOUSE_PS2_SMBUS) += psmouse-smbus.o
elan_i2c-objs := elan_i2c_core.o
elan_i2c-$(CONFIG_MOUSE_ELAN_I2C_I2C) += elan_i2c_i2c.o
elan_i2c-$(CONFIG_MOUSE_ELAN_I2C_SMBUS) += elan_i2c_smbus.o
......@@ -1999,16 +1999,27 @@ static int __init psmouse_init(void)
synaptics_module_init();
hgpk_module_init();
err = psmouse_smbus_module_init();
if (err)
return err;
kpsmoused_wq = alloc_ordered_workqueue("kpsmoused", 0);
if (!kpsmoused_wq) {
pr_err("failed to create kpsmoused workqueue\n");
return -ENOMEM;
err = -ENOMEM;
goto err_smbus_exit;
}
err = serio_register_driver(&psmouse_drv);
if (err)
destroy_workqueue(kpsmoused_wq);
goto err_destroy_wq;
return 0;
err_destroy_wq:
destroy_workqueue(kpsmoused_wq);
err_smbus_exit:
psmouse_smbus_module_exit();
return err;
}
......@@ -2016,6 +2027,7 @@ static void __exit psmouse_exit(void)
{
serio_unregister_driver(&psmouse_drv);
destroy_workqueue(kpsmoused_wq);
psmouse_smbus_module_exit();
}
module_init(psmouse_init);
......
/*
* Copyright (c) 2017 Red Hat, Inc
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/libps2.h>
#include <linux/i2c.h>
#include <linux/serio.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include "psmouse.h"
struct psmouse_smbus_dev {
struct i2c_board_info board;
struct psmouse *psmouse;
struct i2c_client *client;
struct list_head node;
bool dead;
};
static LIST_HEAD(psmouse_smbus_list);
static DEFINE_MUTEX(psmouse_smbus_mutex);
static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
{
struct psmouse_smbus_dev *smbdev;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
return;
mutex_lock(&psmouse_smbus_mutex);
list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
if (smbdev->dead)
continue;
if (smbdev->client)
continue;
/*
* Here would be a good place to check if device is actually
* present, but it seems that SMBus will not respond unless we
* fully reset PS/2 connection. So cross our fingers, and try
* to switch over, hopefully our system will not have too many
* "host notify" I2C adapters.
*/
psmouse_dbg(smbdev->psmouse,
"SMBus candidate adapter appeared, triggering rescan\n");
serio_rescan(smbdev->psmouse->ps2dev.serio);
}
mutex_unlock(&psmouse_smbus_mutex);
}
static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
{
struct psmouse_smbus_dev *smbdev;
mutex_lock(&psmouse_smbus_mutex);
list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
if (smbdev->client == client) {
psmouse_dbg(smbdev->psmouse,
"Marking SMBus companion %s as gone\n",
dev_name(&smbdev->client->dev));
smbdev->client = NULL;
smbdev->dead = true;
serio_rescan(smbdev->psmouse->ps2dev.serio);
}
}
kfree(client->dev.platform_data);
client->dev.platform_data = NULL;
mutex_unlock(&psmouse_smbus_mutex);
}
static int psmouse_smbus_notifier_call(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
if (dev->type == &i2c_adapter_type)
psmouse_smbus_check_adapter(to_i2c_adapter(dev));
break;
case BUS_NOTIFY_REMOVED_DEVICE:
if (dev->type != &i2c_adapter_type)
psmouse_smbus_detach_i2c_client(to_i2c_client(dev));
break;
}
return 0;
}
static struct notifier_block psmouse_smbus_notifier = {
.notifier_call = psmouse_smbus_notifier_call,
};
static psmouse_ret_t psmouse_smbus_process_byte(struct psmouse *psmouse)
{
return PSMOUSE_FULL_PACKET;
}
static int psmouse_smbus_reconnect(struct psmouse *psmouse)
{
psmouse_deactivate(psmouse);
return 0;
}
struct psmouse_smbus_removal_work {
struct work_struct work;
struct i2c_client *client;
};
static void psmouse_smbus_remove_i2c_device(struct work_struct *work)
{
struct psmouse_smbus_removal_work *rwork =
container_of(work, struct psmouse_smbus_removal_work, work);
dev_dbg(&rwork->client->dev, "destroying SMBus companion device\n");
i2c_unregister_device(rwork->client);
kfree(rwork);
}
/*
* This schedules removal of SMBus companion device. We have to do
* it in a separate tread to avoid deadlocking on psmouse_mutex in
* case the device has a trackstick (which is also driven by psmouse).
*
* Note that this may be racing with i2c adapter removal, but we
* can't do anything about that: i2c automatically destroys clients
* attached to an adapter that is being removed. This has to be
* fixed in i2c core.
*/
static void psmouse_smbus_schedule_remove(struct i2c_client *client)
{
struct psmouse_smbus_removal_work *rwork;
rwork = kzalloc(sizeof(*rwork), GFP_KERNEL);
if (rwork) {
INIT_WORK(&rwork->work, psmouse_smbus_remove_i2c_device);
rwork->client = client;
schedule_work(&rwork->work);
}
}
static void psmouse_smbus_disconnect(struct psmouse *psmouse)
{
struct psmouse_smbus_dev *smbdev = psmouse->private;
mutex_lock(&psmouse_smbus_mutex);
list_del(&smbdev->node);
mutex_unlock(&psmouse_smbus_mutex);
if (smbdev->client) {
psmouse_dbg(smbdev->psmouse,
"posting removal request for SMBus companion %s\n",
dev_name(&smbdev->client->dev));
psmouse_smbus_schedule_remove(smbdev->client);
}
kfree(smbdev);
psmouse->private = NULL;
}
static int psmouse_smbus_create_companion(struct device *dev, void *data)
{
struct psmouse_smbus_dev *smbdev = data;
unsigned short addr_list[] = { smbdev->board.addr, I2C_CLIENT_END };
struct i2c_adapter *adapter;
adapter = i2c_verify_adapter(dev);
if (!adapter)
return 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
return 0;
smbdev->client = i2c_new_probed_device(adapter, &smbdev->board,
addr_list, NULL);
if (!smbdev->client)
return 0;
/* We have our(?) device, stop iterating i2c bus. */
return 1;
}
void psmouse_smbus_cleanup(struct psmouse *psmouse)
{
struct psmouse_smbus_dev *smbdev, *tmp;
mutex_lock(&psmouse_smbus_mutex);
list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
if (psmouse == smbdev->psmouse) {
list_del(&smbdev->node);
kfree(smbdev);
}
}
mutex_unlock(&psmouse_smbus_mutex);
}
int psmouse_smbus_init(struct psmouse *psmouse,
const struct i2c_board_info *board,
const void *pdata, size_t pdata_size,
bool leave_breadcrumbs)
{
struct psmouse_smbus_dev *smbdev;
int error;
smbdev = kzalloc(sizeof(*smbdev), GFP_KERNEL);
if (!smbdev)
return -ENOMEM;
smbdev->psmouse = psmouse;
smbdev->board = *board;
smbdev->board.platform_data = kmemdup(pdata, pdata_size, GFP_KERNEL);
if (!smbdev->board.platform_data) {
kfree(smbdev);
return -ENOMEM;
}
psmouse->private = smbdev;
psmouse->protocol_handler = psmouse_smbus_process_byte;
psmouse->reconnect = psmouse_smbus_reconnect;
psmouse->fast_reconnect = psmouse_smbus_reconnect;
psmouse->disconnect = psmouse_smbus_disconnect;
psmouse->resync_time = 0;
psmouse_deactivate(psmouse);
mutex_lock(&psmouse_smbus_mutex);
list_add_tail(&smbdev->node, &psmouse_smbus_list);
mutex_unlock(&psmouse_smbus_mutex);
/* Bind to already existing adapters right away */
error = i2c_for_each_dev(smbdev, psmouse_smbus_create_companion);
if (smbdev->client) {
/* We have our companion device */
return 0;
}
/*
* If we did not create i2c device we will not need platform
* data even if we are leaving breadcrumbs.
*/
kfree(smbdev->board.platform_data);
smbdev->board.platform_data = NULL;
if (error < 0 || !leave_breadcrumbs) {
mutex_lock(&psmouse_smbus_mutex);
list_del(&smbdev->node);
mutex_unlock(&psmouse_smbus_mutex);
kfree(smbdev);
}
return error < 0 ? error : -EAGAIN;
}
int __init psmouse_smbus_module_init(void)
{
int error;
error = bus_register_notifier(&i2c_bus_type, &psmouse_smbus_notifier);
if (error) {
pr_err("failed to register i2c bus notifier: %d\n", error);
return error;
}
return 0;
}
void psmouse_smbus_module_exit(void)
{
bus_unregister_notifier(&i2c_bus_type, &psmouse_smbus_notifier);
flush_scheduled_work();
}
......@@ -209,5 +209,34 @@ static struct psmouse_attribute psmouse_attr_##_name = { \
&(psmouse)->ps2dev.serio->dev, \
psmouse_fmt(format), ##__VA_ARGS__)
#ifdef CONFIG_MOUSE_PS2_SMBUS
int psmouse_smbus_module_init(void);
void psmouse_smbus_module_exit(void);
struct i2c_board_info;
int psmouse_smbus_init(struct psmouse *psmouse,
const struct i2c_board_info *board,
const void *pdata, size_t pdata_size,
bool leave_breadcrumbs);
void psmouse_smbus_cleanup(struct psmouse *psmouse);
#else /* !CONFIG_MOUSE_PS2_SMBUS */
static inline int psmouse_smbus_module_init(void)
{
return 0;
}
static inline void psmouse_smbus_module_exit(void)
{
}
static inline void psmouse_smbus_cleanup(struct psmouse *psmouse)
{
}
#endif /* CONFIG_MOUSE_PS2_SMBUS */
#endif /* _PSMOUSE_H */
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