This driver is a glue between PS/2 devices that enumerate
the RMI4 devices and Elan touchpads to the RMI4 (or Elan)
SMBus driver.
We use an intermediate platform device to not add a
dependency between psmouse and I2C. It also handles
the subtleties of going around the serio mutex lock by
deferring the i2c creation/destruction in a separate
thread.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/input/misc/Kconfig | 11 ++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/ps2_smbus.c | 255 +++++++++++++++++++++++++++++++++++++++++
drivers/input/rmi4/Kconfig | 1 +
4 files changed, 268 insertions(+)
create mode 100644 drivers/input/misc/ps2_smbus.c
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 1ae4d96..e0dfefc 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -832,4 +832,15 @@ config INPUT_HISI_POWERKEY
To compile this driver as a module, choose M here: the
module will be called hisi_powerkey.
+config PS2_SMBUS
+ tristate "Platform Support for PS/2 Nodes also connected over SMBus"
+ depends on I2C
+ help
+ Say Y here if you want to support RMI4 or Elan devices connected to
+ an SMB bus but enumerated through PS/2.
+
+ if unsure, say N.
+ To compile this driver as a module, choose M here: the module will be
+ called ps2_smbus.
+
endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 0b6d025..094a911 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_INPUT_PCSPKR) += pcspkr.o
obj-$(CONFIG_INPUT_PM8941_PWRKEY) += pm8941-pwrkey.o
obj-$(CONFIG_INPUT_PM8XXX_VIBRATOR) += pm8xxx-vibrator.o
obj-$(CONFIG_INPUT_PMIC8XXX_PWRKEY) += pmic8xxx-pwrkey.o
+obj-$(CONFIG_PS2_SMBUS) += ps2_smbus.o
obj-$(CONFIG_INPUT_POWERMATE) += powermate.o
obj-$(CONFIG_INPUT_PWM_BEEPER) += pwm-beeper.o
obj-$(CONFIG_INPUT_RB532_BUTTON) += rb532_button.o
diff --git a/drivers/input/misc/ps2_smbus.c b/drivers/input/misc/ps2_smbus.c
new file mode 100644
index 0000000..d1f27ed
--- /dev/null
+++ b/drivers/input/misc/ps2_smbus.c
@@ -0,0 +1,255 @@
+/*
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/rmi.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Platform PS/2 - SMBus bridge driver");
+MODULE_LICENSE("GPL");
+
+static struct workqueue_struct *kps2smbus_wq;
+DEFINE_MUTEX(ps2smbus_mutex);
+
+enum ps2smbus_type {
+ PS2SMBUS_SYNAPTICS_RMI4,
+};
+
+struct ps2smbus {
+ struct i2c_client *smbus_client;
+ struct notifier_block i2c_notifier;
+ enum ps2smbus_type type;
+ void *pdata;
+};
+
+enum ps2smbus_event_type {
+ PS2SMBUS_REGISTER_DEVICE,
+ PS2SMBUS_UNREGISTER_DEVICE,
+};
+
+struct ps2smbus_work {
+ struct work_struct work;
+ enum ps2smbus_event_type type;
+ struct ps2smbus *ps2smbus;
+ struct i2c_adapter *adap;
+};
+
+static void ps2smbus_create_rmi4(struct ps2smbus *ps2smbus,
+ struct i2c_adapter *adap)
+{
+ const struct i2c_board_info i2c_info = {
+ I2C_BOARD_INFO("rmi4_smbus", 0x2c),
+ .platform_data = ps2smbus->pdata,
+ .flags = I2C_CLIENT_HOST_NOTIFY,
+ };
+
+ ps2smbus->smbus_client = i2c_new_device(adap, &i2c_info);
+}
+
+static void ps2smbus_worker(struct work_struct *work)
+{
+ struct ps2smbus_work *ps2smbus_work;
+ struct i2c_client *client;
+
+ ps2smbus_work = container_of(work, struct ps2smbus_work, work);
+ client = ps2smbus_work->ps2smbus->smbus_client;
+
+ mutex_lock(&ps2smbus_mutex);
+
+ switch (ps2smbus_work->type) {
+ case PS2SMBUS_REGISTER_DEVICE:
+ if (ps2smbus_work->ps2smbus->type == PS2SMBUS_SYNAPTICS_RMI4)
+ ps2smbus_create_rmi4(ps2smbus_work->ps2smbus,
+ ps2smbus_work->adap);
+ break;
+ case PS2SMBUS_UNREGISTER_DEVICE:
+ if (client)
+ i2c_unregister_device(client);
+ break;
+ }
+
+ kfree(ps2smbus_work);
+
+ mutex_unlock(&ps2smbus_mutex);
+}
+
+static int ps2smbus_schedule_work(enum ps2smbus_event_type type,
+ struct ps2smbus *ps2smbus,
+ struct i2c_adapter *adap)
+{
+ struct ps2smbus_work *ps2smbus_work;
+
+ ps2smbus_work = kzalloc(sizeof(*ps2smbus_work), GFP_KERNEL);
+ if (!ps2smbus_work)
+ return -ENOMEM;
+
+ ps2smbus_work->type = type;
+ ps2smbus_work->ps2smbus = ps2smbus;
+ ps2smbus_work->adap = adap;
+
+ INIT_WORK(&ps2smbus_work->work, ps2smbus_worker);
+
+ queue_work(kps2smbus_wq, &ps2smbus_work->work);
+
+ return 0;
+}
+
+static int ps2smbus_attach_i2c_device(struct device *dev, void *data)
+{
+ struct ps2smbus *ps2smbus = data;
+ struct i2c_adapter *adap;
+
+ if (dev->type != &i2c_adapter_type)
+ return 0;
+
+ adap = to_i2c_adapter(dev);
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
+ return 0;
+
+ if (ps2smbus->smbus_client)
+ return 0;
+
+ ps2smbus_schedule_work(PS2SMBUS_REGISTER_DEVICE, ps2smbus, adap);
+
+ pr_debug("ps2smbus: adapter [%s] registered\n", adap->name);
+ return 0;
+}
+
+static int ps2smbus_detach_i2c_device(struct device *dev,
+ struct ps2smbus *ps2smbus)
+{
+ struct i2c_client *client;
+
+ if (dev->type == &i2c_adapter_type)
+ return 0;
+
+ mutex_lock(&ps2smbus_mutex);
+
+ client = to_i2c_client(dev);
+ if (client == ps2smbus->smbus_client)
+ ps2smbus->smbus_client = NULL;
+
+ mutex_unlock(&ps2smbus_mutex);
+
+ pr_debug("ps2smbus: client [%s] unregistered\n", client->name);
+ return 0;
+}
+
+static int ps2smbus_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+ struct ps2smbus *ps2smbus;
+
+ ps2smbus = container_of(nb, struct ps2smbus, i2c_notifier);
+
+ switch (action) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ return ps2smbus_attach_i2c_device(dev, ps2smbus);
+ case BUS_NOTIFY_DEL_DEVICE:
+ return ps2smbus_detach_i2c_device(dev, ps2smbus);
+ }
+
+ return 0;
+}
+
+static int ps2smbus_probe(struct platform_device *pdev)
+{
+ struct rmi_device_platform_data *rmi_pdata = pdev->dev.platform_data;
+ struct serio *parent;
+ struct ps2smbus *ps2smbus;
+ int error;
+
+ ps2smbus = devm_kzalloc(&pdev->dev, sizeof(struct ps2smbus),
+ GFP_KERNEL);
+ if (!ps2smbus)
+ return -ENOMEM;
+
+ ps2smbus->i2c_notifier.notifier_call = ps2smbus_notifier_call;
+ ps2smbus->pdata = pdev->dev.platform_data;
+ ps2smbus->type = pdev->id_entry->driver_data;
+ if (pdev->dev.parent) {
+ parent = to_serio_port(pdev->dev.parent);
+ if (ps2smbus->type == PS2SMBUS_SYNAPTICS_RMI4)
+ rmi_pdata->parent = parent;
+ }
+
+ /* Keep track of adapters which will be added or removed later */
+ error = bus_register_notifier(&i2c_bus_type, &ps2smbus->i2c_notifier);
+ if (error)
+ return error;
+
+ /* Bind to already existing adapters right away */
+ i2c_for_each_dev(ps2smbus, ps2smbus_attach_i2c_device);
+
+ platform_set_drvdata(pdev, ps2smbus);
+
+ return 0;
+}
+
+static int ps2smbus_remove(struct platform_device *pdev)
+{
+ struct ps2smbus *ps2smbus = platform_get_drvdata(pdev);
+
+ bus_unregister_notifier(&i2c_bus_type, &ps2smbus->i2c_notifier);
+
+ if (ps2smbus->smbus_client)
+ ps2smbus_schedule_work(PS2SMBUS_UNREGISTER_DEVICE, ps2smbus,
+ NULL);
+
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static const struct platform_device_id ps2smbus_id_table[] = {
+ { .name = "rmi4", .driver_data = PS2SMBUS_SYNAPTICS_RMI4 },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, ps2smbus_id_table);
+
+static struct platform_driver ps2smbus_drv = {
+ .driver = {
+ .name = "ps2smbus",
+ },
+ .probe = ps2smbus_probe,
+ .remove = ps2smbus_remove,
+ .id_table = ps2smbus_id_table,
+};
+
+static int __init ps2smbus_init(void)
+{
+ int err;
+
+ kps2smbus_wq = alloc_ordered_workqueue("kps2smbusd", WQ_MEM_RECLAIM);
+ if (!kps2smbus_wq) {
+ pr_err("failed to create kps2smbusd workqueue\n");
+ return -ENOMEM;
+ }
+
+ err = platform_driver_register(&ps2smbus_drv);
+ if (err)
+ destroy_workqueue(kps2smbus_wq);
+
+ return err;
+}
+
+static void __exit ps2smbus_exit(void)
+{
+ platform_driver_unregister(&ps2smbus_drv);
+ destroy_workqueue(kps2smbus_wq);
+}
+
+module_init(ps2smbus_init);
+module_exit(ps2smbus_exit);
diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index 30cc627..eb74678 100644
--- a/drivers/input/rmi4/Kconfig
+++ b/drivers/input/rmi4/Kconfig
@@ -30,6 +30,7 @@ config RMI4_SPI
config RMI4_SMB
tristate "RMI4 SMB Support"
depends on RMI4_CORE && I2C
+ select RMI4_PLATFORM
help
Say Y here if you want to support RMI4 devices connected to an SMB
bus.
--
2.9.3
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