diff options
author | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2018-05-23 02:28:23 +0200 |
---|---|---|
committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2018-05-24 01:49:22 +0200 |
commit | 21c48dbde0944e3d52468008321900af3bdafcf1 (patch) | |
tree | 076300cb80f45799824b1f550fe04bdf9a3c8983 /drivers/input/mouse/elantech.c | |
parent | Input: elantech - query the resolution in query_info (diff) | |
download | linux-21c48dbde0944e3d52468008321900af3bdafcf1.tar.xz linux-21c48dbde0944e3d52468008321900af3bdafcf1.zip |
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: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input/mouse/elantech.c')
-rw-r--r-- | drivers/input/mouse/elantech.c | 188 |
1 files changed, 184 insertions, 4 deletions
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index a2a14a31edb5..510e7c0622d3 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -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; +} |