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Commit 21c48dbd authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Dmitry Torokhov
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Input: elantech - add support for SMBus devices 



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: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: default avatarKT Liao <kt.liao@emc.com.tw>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 80212ed7

drivers/input/mouse/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -133,6 +133,18 @@ config MOUSE_PS2_ELANTECH 


	  If unsure, say N.



config MOUSE_PS2_ELANTECH_SMBUS

	bool "Elantech PS/2 SMbus companion" if EXPERT

	default y

	depends on MOUSE_PS2 && MOUSE_PS2_ELANTECH

	depends on I2C=y || I2C=MOUSE_PS2

	select MOUSE_PS2_SMBUS

	help

	  Say Y here if you have a Elantech touchpad connected to

	  to an SMBus, but enumerated through PS/2.



	  If unsure, say Y.



config MOUSE_PS2_SENTELIC

	bool "Sentelic Finger Sensing Pad PS/2 protocol extension"

	depends on MOUSE_PS2

drivers/input/mouse/elantech.c

+184 −4
Original line number Diff line number Diff line
@@ -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;

}

drivers/input/mouse/elantech.h

+24 −0
Original line number Diff line number Diff line
@@ -106,6 +106,15 @@ 
 */

#define ETP_WEIGHT_VALUE		5



/*

 * Bus information on 3rd byte of query ETP_RESOLUTION_QUERY(0x04)

 */

#define ETP_BUS_PS2_ONLY		0

#define ETP_BUS_SMB_ALERT_ONLY		1

#define ETP_BUS_SMB_HST_NTFY_ONLY	2

#define ETP_BUS_PS2_SMB_ALERT		3

#define ETP_BUS_PS2_SMB_HST_NTFY	4



/*

 * The base position for one finger, v4 hardware

 */
@@ -122,6 +131,7 @@ struct elantech_device_info { 
	unsigned int fw_version;

	unsigned int x_res;

	unsigned int y_res;

	unsigned int bus;

	bool paritycheck;

	bool jumpy_cursor;

	bool reports_pressure;
@@ -156,6 +166,7 @@ struct elantech_data { 


#ifdef CONFIG_MOUSE_PS2_ELANTECH

int elantech_detect(struct psmouse *psmouse, bool set_properties);

int elantech_init_ps2(struct psmouse *psmouse);

int elantech_init(struct psmouse *psmouse);

#else

static inline int elantech_detect(struct psmouse *psmouse, bool set_properties)
@@ -166,6 +177,19 @@ static inline int elantech_init(struct psmouse *psmouse) 
{

	return -ENOSYS;

}

static inline int elantech_init_ps2(struct psmouse *psmouse)

{

	return -ENOSYS;

}

#endif /* CONFIG_MOUSE_PS2_ELANTECH */



#if defined(CONFIG_MOUSE_PS2_ELANTECH_SMBUS)

int elantech_init_smbus(struct psmouse *psmouse);

#else

static inline int elantech_init_smbus(struct psmouse *psmouse)

{

	return -ENOSYS;

}

#endif /* CONFIG_MOUSE_PS2_ELANTECH_SMBUS */



#endif

drivers/input/mouse/psmouse-base.c

+18 −3
Original line number Diff line number Diff line
@@ -856,7 +856,17 @@ static const struct psmouse_protocol psmouse_protocols[] = { 
		.name		= "ETPS/2",

		.alias		= "elantech",

		.detect		= elantech_detect,

		.init		= elantech_init,

		.init		= elantech_init_ps2,

	},

#endif

#ifdef CONFIG_MOUSE_PS2_ELANTECH_SMBUS

	{

		.type		= PSMOUSE_ELANTECH_SMBUS,

		.name		= "ETSMBus",

		.alias		= "elantech-smbus",

		.detect		= elantech_detect,

		.init		= elantech_init_smbus,

		.smbus_companion = true,

	},

#endif

#ifdef CONFIG_MOUSE_PS2_SENTELIC
@@ -1158,8 +1168,13 @@ static int psmouse_extensions(struct psmouse *psmouse, 
	/* Try Elantech touchpad */

	if (max_proto > PSMOUSE_IMEX &&

	    psmouse_try_protocol(psmouse, PSMOUSE_ELANTECH,

				 &max_proto, set_properties, true)) {

				 &max_proto, set_properties, false)) {

		if (!set_properties)

			return PSMOUSE_ELANTECH;



		ret = elantech_init(psmouse);

		if (ret >= 0)

			return ret;

	}



	if (max_proto > PSMOUSE_IMEX) {

drivers/input/mouse/psmouse-smbus.c

+7 −4
Original line number Diff line number Diff line
@@ -237,11 +237,14 @@ int psmouse_smbus_init(struct psmouse *psmouse, 
	smbdev->psmouse = psmouse;

	smbdev->board = *board;



	smbdev->board.platform_data = kmemdup(pdata, pdata_size, GFP_KERNEL);

	if (pdata) {

		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;