[PATCH 10/10] Input: elantech - automatically bind an SMBus device when acceptable
From: Benjamin Tissoires
Date: Tue Jan 10 2017 - 11:12:14 EST
In the same way Synaptics devices can use a secondary bus with a better
bandwidth, Elantech touchpads can also be talked over SMBus.
It's unclear right now which devices have this capability, so use a module
parameter to enable/disable this. We can then whitelist them until we find
a more reliable way of detecting them.
When provided, elan_i2c also prevents the PS/2 node from resuming by
calling serio_deactivate().
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/input/misc/ps2_smbus.c | 23 +++++++++++++++-
drivers/input/mouse/elan_i2c.h | 2 ++
drivers/input/mouse/elan_i2c_core.c | 8 ++++++
drivers/input/mouse/elantech.c | 54 +++++++++++++++++++++++++++++++++++++
drivers/input/mouse/elantech.h | 3 +++
5 files changed, 89 insertions(+), 1 deletion(-)
diff --git a/drivers/input/misc/ps2_smbus.c b/drivers/input/misc/ps2_smbus.c
index d1f27ed..2463afd 100644
--- a/drivers/input/misc/ps2_smbus.c
+++ b/drivers/input/misc/ps2_smbus.c
@@ -23,6 +23,7 @@ DEFINE_MUTEX(ps2smbus_mutex);
enum ps2smbus_type {
PS2SMBUS_SYNAPTICS_RMI4,
+ PS2SMBUS_ELAN_SMBUS,
};
struct ps2smbus {
@@ -56,6 +57,18 @@ static void ps2smbus_create_rmi4(struct ps2smbus *ps2smbus,
ps2smbus->smbus_client = i2c_new_device(adap, &i2c_info);
}
+static void ps2smbus_create_elan(struct ps2smbus *ps2smbus,
+ struct i2c_adapter *adap)
+{
+ const struct i2c_board_info i2c_info = {
+ I2C_BOARD_INFO("elan_i2c", 0x15),
+ .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;
@@ -68,9 +81,16 @@ static void ps2smbus_worker(struct work_struct *work)
switch (ps2smbus_work->type) {
case PS2SMBUS_REGISTER_DEVICE:
- if (ps2smbus_work->ps2smbus->type == PS2SMBUS_SYNAPTICS_RMI4)
+ switch (ps2smbus_work->ps2smbus->type) {
+ case PS2SMBUS_SYNAPTICS_RMI4:
ps2smbus_create_rmi4(ps2smbus_work->ps2smbus,
ps2smbus_work->adap);
+ break;
+ case PS2SMBUS_ELAN_SMBUS:
+ ps2smbus_create_elan(ps2smbus_work->ps2smbus,
+ ps2smbus_work->adap);
+ break;
+ }
break;
case PS2SMBUS_UNREGISTER_DEVICE:
if (client)
@@ -215,6 +235,7 @@ static int ps2smbus_remove(struct platform_device *pdev)
static const struct platform_device_id ps2smbus_id_table[] = {
{ .name = "rmi4", .driver_data = PS2SMBUS_SYNAPTICS_RMI4 },
+ { .name = "elan_smbus", .driver_data = PS2SMBUS_ELAN_SMBUS },
{ }
};
MODULE_DEVICE_TABLE(platform, ps2smbus_id_table);
diff --git a/drivers/input/mouse/elan_i2c.h b/drivers/input/mouse/elan_i2c.h
index 468763a..d555015 100644
--- a/drivers/input/mouse/elan_i2c.h
+++ b/drivers/input/mouse/elan_i2c.h
@@ -37,6 +37,7 @@
#define ETP_FW_SIGNATURE_SIZE 6
struct i2c_client;
+struct serio;
struct completion;
enum tp_mode {
@@ -93,6 +94,7 @@ extern const struct elan_transport_ops elan_smbus_ops, elan_i2c_ops;
* be created and handled by the driver.
*/
struct elan_platform_data {
+ struct serio *parent;
bool trackpoint;
};
diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index ca9adf7..97ff61d 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -30,6 +30,7 @@
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/sched.h>
+#include <linux/serio.h>
#include <linux/input.h>
#include <linux/uaccess.h>
#include <linux/jiffies.h>
@@ -1092,6 +1093,7 @@ static int elan_probe(struct i2c_client *client,
const struct elan_transport_ops *transport_ops;
struct device *dev = &client->dev;
struct elan_tp_data *data;
+ struct serio *parent = NULL;
unsigned long irqflags;
bool has_trackpoint = pdata && pdata->trackpoint;
int error;
@@ -1122,6 +1124,12 @@ static int elan_probe(struct i2c_client *client,
init_completion(&data->fw_completion);
mutex_init(&data->sysfs_mutex);
+ if (pdata)
+ parent = pdata->parent;
+
+ /* Make sure the driver stays here on resume */
+ serio_deactivate(parent);
+
data->vcc = devm_regulator_get(&client->dev, "vcc");
if (IS_ERR(data->vcc)) {
error = PTR_ERR(data->vcc);
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index db7d1d6..f83940d 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -16,11 +16,28 @@
#include <linux/module.h>
#include <linux/input.h>
#include <linux/input/mt.h>
+#include <linux/platform_device.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <asm/unaligned.h>
#include "psmouse.h"
#include "elantech.h"
+#include "elan_i2c.h"
+
+/*
+ * The newest Elan devices can use a secondary bus (over SMBus) which
+ * provides a better bandwidth and allow a better control of the touchpads.
+ * This is used to decide if we need to use this bus or not.
+ */
+enum {
+ ELAN_SMBUS_NOT_SET = -1,
+ ELAN_SMBUS_OFF,
+ ELAN_SMBUS_ON,
+};
+
+static int elan_smbus = ELAN_SMBUS_OFF;
+module_param_named(elan_smbus, elan_smbus, int, 0644);
+MODULE_PARM_DESC(elan_smbus, "Use a secondary bus for the Elantech device.");
#define elantech_debug(fmt, ...) \
do { \
@@ -1470,6 +1487,11 @@ static void elantech_disconnect(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
+ if (etd->smbus) {
+ platform_device_unregister(etd->smbus);
+ etd->smbus = NULL;
+ }
+
if (etd->tp_dev)
input_unregister_device(etd->tp_dev);
sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
@@ -1629,6 +1651,35 @@ static int elantech_set_properties(struct elantech_data *etd)
return 0;
}
+static int smbus_id;
+
+static int elan_create_smbus(struct psmouse *psmouse, struct elantech_data *etd)
+{
+ struct platform_device *pdev;
+ struct platform_device_info pdevinfo;
+ struct elan_platform_data pdata = {
+ .trackpoint = !!etd->tp_dev,
+ };
+
+ if (etd->smbus)
+ return -EINVAL;
+
+ memset(&pdevinfo, 0, sizeof(pdevinfo));
+ pdevinfo.name = "elan_smbus";
+ pdevinfo.id = smbus_id++;
+ pdevinfo.data = &pdata;
+ pdevinfo.size_data = sizeof(pdata);
+ pdevinfo.parent = &psmouse->ps2dev.serio->dev;
+
+ pdev = platform_device_register_full(&pdevinfo);
+ if (IS_ERR(pdev))
+ return PTR_ERR(pdev);
+
+ etd->smbus = pdev;
+
+ return 0;
+}
+
/*
* Initialize the touchpad and create sysfs entries
*/
@@ -1751,6 +1802,9 @@ int elantech_init(struct psmouse *psmouse)
psmouse->reconnect = elantech_reconnect;
psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
+ if (etd->hw_version == 4 && elan_smbus == ELAN_SMBUS_ON)
+ elan_create_smbus(psmouse, etd);
+
return 0;
init_fail_tp_reg:
input_free_device(tp_dev);
diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index e1cbf40..299f2e3d 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -144,6 +144,9 @@ struct elantech_data {
unsigned char parity[256];
int (*send_cmd)(struct psmouse *psmouse, unsigned char c, unsigned char *param);
void (*original_set_rate)(struct psmouse *psmouse, unsigned int rate);
+
+ /* SMBus handling */
+ struct platform_device *smbus;
};
#ifdef CONFIG_MOUSE_PS2_ELANTECH
--
2.9.3