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author | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2017-03-02 10:48:23 -0800 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-03-25 10:37:29 -0700 |
commit | 8eb92e5c91338eb19f86ffb2232258337ebf905b (patch) | |
tree | 2945e2b7f324c0a3d8da4aebefa27b145ffb7d6f /drivers | |
parent | c774326a219536ab615d68a22875673f6f608b62 (diff) | |
download | linux-stable-8eb92e5c91338eb19f86ffb2232258337ebf905b.tar.gz linux-stable-8eb92e5c91338eb19f86ffb2232258337ebf905b.tar.bz2 linux-stable-8eb92e5c91338eb19f86ffb2232258337ebf905b.zip |
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: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/input/mouse/Kconfig | 4 | ||||
-rw-r--r-- | drivers/input/mouse/Makefile | 2 | ||||
-rw-r--r-- | drivers/input/mouse/psmouse-base.c | 16 | ||||
-rw-r--r-- | drivers/input/mouse/psmouse-smbus.c | 294 | ||||
-rw-r--r-- | drivers/input/mouse/psmouse.h | 29 |
5 files changed, 343 insertions, 2 deletions
diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig index 096abb4ad5cd..87bde8a210c7 100644 --- a/drivers/input/mouse/Kconfig +++ b/drivers/input/mouse/Kconfig @@ -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 diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile index 6168b134937b..56bf0ad877c6 100644 --- a/drivers/input/mouse/Makefile +++ b/drivers/input/mouse/Makefile @@ -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 diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c index a84f8ed2ba5d..ab9bfe2af381 100644 --- a/drivers/input/mouse/psmouse-base.c +++ b/drivers/input/mouse/psmouse-base.c @@ -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); diff --git a/drivers/input/mouse/psmouse-smbus.c b/drivers/input/mouse/psmouse-smbus.c new file mode 100644 index 000000000000..061c1cc44aef --- /dev/null +++ b/drivers/input/mouse/psmouse-smbus.c @@ -0,0 +1,294 @@ +/* + * 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(); +} diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h index e853dee05e79..05110832109c 100644 --- a/drivers/input/mouse/psmouse.h +++ b/drivers/input/mouse/psmouse.h @@ -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 */ |