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 <[email protected]> --- 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
