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Input: elantech - add support for SMBus devices

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Many of the Elantech devices are connected through PS/2 and a different
bus (SMBus or plain I2C).

To not break any existing device, we only enable SMBus based
on a module parameter. If some laptops require the quirk to
be set, we will have to rely on a list of PNPIds or MDI matching
to individually expose those hardware over SMBus.
the parameter mentioned above is elantech_smbus from the psmouse
module.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Benjamin Tissoires
2018-05-22 17:28:23 -07:00
committed by Dmitry Torokhov
parent 80212ed743
commit 21c48dbde0
6 changed files with 246 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

188
drivers/input/mouse/elantech.c
View File

@@ -14,13 +14,16 @@
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/i2c.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"
#define elantech_debug(fmt, ...) \
do { \
@@ -1084,7 +1087,8 @@ static unsigned int elantech_convert_res(unsigned int val)
static int elantech_get_resolution_v4(struct psmouse *psmouse,
unsigned int *x_res,
unsigned int *y_res)
unsigned int *y_res,
unsigned int *bus)
{
unsigned char param[3];
@@ -1093,6 +1097,7 @@ static int elantech_get_resolution_v4(struct psmouse *psmouse,
*x_res = elantech_convert_res(param[1] & 0x0f);
*y_res = elantech_convert_res((param[1] & 0xf0) >> 4);
*bus = param[2];
return 0;
}
@@ -1474,6 +1479,12 @@ static void elantech_disconnect(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
/*
* We might have left a breadcrumb when trying to
* set up SMbus companion.
*/
psmouse_smbus_cleanup(psmouse);
if (etd->tp_dev)
input_unregister_device(etd->tp_dev);
sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
@@ -1659,6 +1670,8 @@ static int elantech_query_info(struct psmouse *psmouse,
{
unsigned char param[3];
memset(info, 0, sizeof(*info));
/*
* Do the version query again so we can store the result
*/
@@ -1717,7 +1730,8 @@ static int elantech_query_info(struct psmouse *psmouse,
if (info->hw_version == 4) {
if (elantech_get_resolution_v4(psmouse,
&info->x_res,
&info->y_res)) {
&info->y_res,
&info->bus)) {
psmouse_warn(psmouse,
"failed to query resolution data.\n");
}
@@ -1726,6 +1740,129 @@ static int elantech_query_info(struct psmouse *psmouse,
return 0;
}
#if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
/*
* The newest Elantech device 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 {
ELANTECH_SMBUS_NOT_SET = -1,
ELANTECH_SMBUS_OFF,
ELANTECH_SMBUS_ON,
};
static int elantech_smbus = IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ?
ELANTECH_SMBUS_NOT_SET : ELANTECH_SMBUS_OFF;
module_param_named(elantech_smbus, elantech_smbus, int, 0644);
MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");
static int elantech_create_smbus(struct psmouse *psmouse,
struct elantech_device_info *info,
bool leave_breadcrumbs)
{
const struct property_entry i2c_properties[] = {
PROPERTY_ENTRY_BOOL("elan,trackpoint"),
{ },
};
struct i2c_board_info smbus_board = {
I2C_BOARD_INFO("elan_i2c", 0x15),
.flags = I2C_CLIENT_HOST_NOTIFY,
};
if (info->has_trackpoint)
smbus_board.properties = i2c_properties;
return psmouse_smbus_init(psmouse, &smbus_board, NULL, 0,
leave_breadcrumbs);
}
/**
* elantech_setup_smbus - called once the PS/2 devices are enumerated
* and decides to instantiate a SMBus InterTouch device.
*/
static int elantech_setup_smbus(struct psmouse *psmouse,
struct elantech_device_info *info,
bool leave_breadcrumbs)
{
int error;
if (elantech_smbus == ELANTECH_SMBUS_OFF)
return -ENXIO;
if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) {
/*
* FIXME:
* constraint the I2C capable devices by using FW version,
* board version, or by using DMI matching
*/
return -ENXIO;
}
psmouse_info(psmouse, "Trying to set up SMBus access\n");
error = elantech_create_smbus(psmouse, info, leave_breadcrumbs);
if (error) {
if (error == -EAGAIN)
psmouse_info(psmouse, "SMbus companion is not ready yet\n");
else
psmouse_err(psmouse, "unable to create intertouch device\n");
return error;
}
return 0;
}
static bool elantech_use_host_notify(struct psmouse *psmouse,
struct elantech_device_info *info)
{
switch (info->bus) {
case ETP_BUS_PS2_ONLY:
/* expected case */
break;
case ETP_BUS_SMB_ALERT_ONLY:
/* fall-through */
case ETP_BUS_PS2_SMB_ALERT:
psmouse_dbg(psmouse, "Ignoring SMBus provider through alert protocol.\n");
break;
case ETP_BUS_SMB_HST_NTFY_ONLY:
/* fall-through */
case ETP_BUS_PS2_SMB_HST_NTFY:
return true;
default:
psmouse_dbg(psmouse,
"Ignoring SMBus bus provider %d.\n",
info->bus);
}
return false;
}
int elantech_init_smbus(struct psmouse *psmouse)
{
struct elantech_device_info info;
int error = -EINVAL;
psmouse_reset(psmouse);
error = elantech_query_info(psmouse, &info);
if (error)
goto init_fail;
if (info.hw_version < 4) {
error = -ENXIO;
goto init_fail;
}
return elantech_create_smbus(psmouse, &info, false);
init_fail:
psmouse_reset(psmouse);
return error;
}
#endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
/*
* Initialize the touchpad and create sysfs entries
*/
@@ -1734,7 +1871,7 @@ static int elantech_setup_ps2(struct psmouse *psmouse,
{
struct elantech_data *etd;
int i;
int error;
int error = -EINVAL;
struct input_dev *tp_dev;
psmouse->private = etd = kzalloc(sizeof(*etd), GFP_KERNEL);
@@ -1821,7 +1958,7 @@ static int elantech_setup_ps2(struct psmouse *psmouse,
return error;
}
int elantech_init(struct psmouse *psmouse)
int elantech_init_ps2(struct psmouse *psmouse)
{
struct elantech_device_info info;
int error = -EINVAL;
@@ -1841,3 +1978,46 @@ int elantech_init(struct psmouse *psmouse)
psmouse_reset(psmouse);
return error;
}
int elantech_init(struct psmouse *psmouse)
{
struct elantech_device_info info;
int error = -EINVAL;
psmouse_reset(psmouse);
error = elantech_query_info(psmouse, &info);
if (error)
goto init_fail;
#if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)
if (elantech_use_host_notify(psmouse, &info)) {
if (!IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) ||
!IS_ENABLED(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)) {
psmouse_warn(psmouse,
"The touchpad can support a better bus than the too old PS/2 protocol. "
"Make sure MOUSE_PS2_ELANTECH_SMBUS and MOUSE_ELAN_I2C_SMBUS are enabled to get a better touchpad experience.\n");
}
error = elantech_setup_smbus(psmouse, &info, true);
if (!error)
return PSMOUSE_ELANTECH_SMBUS;
}
#endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */
error = elantech_setup_ps2(psmouse, &info);
if (error < 0) {
/*
* Not using any flavor of Elantech support, so clean up
* SMbus breadcrumbs, if any.
*/
psmouse_smbus_cleanup(psmouse);
goto init_fail;
}
return PSMOUSE_ELANTECH;
init_fail:
psmouse_reset(psmouse);
return error;
}