[PATCH v2 3/9] Input: elan_i2c - add trackstick report

From: Benjamin Tissoires
Date: Mon Apr 09 2018 - 05:11:18 EST


The Elan touchpads over I2C/SMBus also can handle a
trackstick. Unfortunately, nothing tells us if the
device supports trackstick (the information lies in
the PS/2 node), so rely on a platform data to enable
or not the trackstick node.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1313939

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

---

changes in v2:
- use of generic device property instead of platform data so
device tree can also make use of it
---
.../devicetree/bindings/input/elan_i2c.txt | 1 +
drivers/input/mouse/elan_i2c_core.c | 90 +++++++++++++++++++++-
2 files changed, 88 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/elan_i2c.txt b/Documentation/devicetree/bindings/input/elan_i2c.txt
index ee3242c4ba67..d80a83583238 100644
--- a/Documentation/devicetree/bindings/input/elan_i2c.txt
+++ b/Documentation/devicetree/bindings/input/elan_i2c.txt
@@ -14,6 +14,7 @@ Optional properties:
- pinctrl-0: a phandle pointing to the pin settings for the device (see
pinctrl binding [1]).
- vcc-supply: a phandle for the regulator supplying 3.3V power.
+- elan,trackpoint: touchpad can support a trackpoint (boolean)

[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
[1]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index 75e757520ef0..44e970931926 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -36,6 +36,7 @@
#include <linux/jiffies.h>
#include <linux/completion.h>
#include <linux/of.h>
+#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <asm/unaligned.h>

@@ -51,6 +52,7 @@
#define ETP_MAX_FINGERS 5
#define ETP_FINGER_DATA_LEN 5
#define ETP_REPORT_ID 0x5D
+#define ETP_TP_REPORT_ID 0x5E
#define ETP_REPORT_ID_OFFSET 2
#define ETP_TOUCH_INFO_OFFSET 3
#define ETP_FINGER_DATA_OFFSET 4
@@ -61,6 +63,7 @@
struct elan_tp_data {
struct i2c_client *client;
struct input_dev *input;
+ struct input_dev *tp_input; /* trackpoint input node */
struct regulator *vcc;

const struct elan_transport_ops *ops;
@@ -930,6 +933,34 @@ static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
input_sync(input);
}

+static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
+{
+ struct input_dev *input = data->tp_input;
+ u8 *packet = &report[ETP_REPORT_ID_OFFSET + 1];
+ int x, y;
+
+ if (!data->tp_input) {
+ dev_warn_once(&data->client->dev,
+ "received a trackpoint report while no trackpoint device has been created.\n"
+ "Please report upstream.\n");
+ return;
+ }
+
+ input_report_key(input, BTN_LEFT, packet[0] & 0x01);
+ input_report_key(input, BTN_RIGHT, packet[0] & 0x02);
+ input_report_key(input, BTN_MIDDLE, packet[0] & 0x04);
+
+ if ((packet[3] & 0x0F) == 0x06) {
+ x = packet[4] - (int)((packet[1]^0x80) << 1);
+ y = (int)((packet[2]^0x80) << 1) - packet[5];
+
+ input_report_rel(input, REL_X, x);
+ input_report_rel(input, REL_Y, y);
+ }
+
+ input_sync(input);
+}
+
static irqreturn_t elan_isr(int irq, void *dev_id)
{
struct elan_tp_data *data = dev_id;
@@ -951,11 +982,17 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
if (error)
goto out;

- if (report[ETP_REPORT_ID_OFFSET] != ETP_REPORT_ID)
+ switch (report[ETP_REPORT_ID_OFFSET]) {
+ case ETP_REPORT_ID:
+ elan_report_absolute(data, report);
+ break;
+ case ETP_TP_REPORT_ID:
+ elan_report_trackpoint(data, report);
+ break;
+ default:
dev_err(dev, "invalid report id data (%x)\n",
report[ETP_REPORT_ID_OFFSET]);
- else
- elan_report_absolute(data, report);
+ }

out:
return IRQ_HANDLED;
@@ -966,6 +1003,37 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
* Elan initialization functions
******************************************************************
*/
+
+static int elan_setup_trackpoint_input_device(struct elan_tp_data *data)
+{
+ struct device *dev = &data->client->dev;
+ struct input_dev *input;
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = "Elan TrackPoint";
+ input->id.bustype = BUS_I2C;
+ input->id.vendor = ELAN_VENDOR_ID;
+ input->id.product = data->product_id;
+ input_set_drvdata(input, data);
+
+ input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
+ input->relbit[BIT_WORD(REL_X)] =
+ BIT_MASK(REL_X) | BIT_MASK(REL_Y);
+ input->keybit[BIT_WORD(BTN_LEFT)] =
+ BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) |
+ BIT_MASK(BTN_RIGHT);
+
+ __set_bit(INPUT_PROP_POINTER, input->propbit);
+ __set_bit(INPUT_PROP_POINTING_STICK, input->propbit);
+
+ data->tp_input = input;
+
+ return 0;
+}
+
static int elan_setup_input_device(struct elan_tp_data *data)
{
struct device *dev = &data->client->dev;
@@ -1140,6 +1208,12 @@ static int elan_probe(struct i2c_client *client,
if (error)
return error;

+ if (device_property_read_bool(&client->dev, "elan,trackpoint")) {
+ error = elan_setup_trackpoint_input_device(data);
+ if (error)
+ return error;
+ }
+
/*
* Platform code (ACPI, DTS) should normally set up interrupt
* for us, but in case it did not let's fall back to using falling
@@ -1177,6 +1251,16 @@ static int elan_probe(struct i2c_client *client,
return error;
}

+ if (data->tp_input) {
+ error = input_register_device(data->tp_input);
+ if (error) {
+ dev_err(&client->dev,
+ "failed to register TrackPoint input device: %d\n",
+ error);
+ return error;
+ }
+ }
+
/*
* Systems using device tree should set up wakeup via DTS,
* the rest will configure device as wakeup source by default.
--
2.14.3