Input: mpr121 - add polling mode
In case the interrupt line is not available, polling can be used
to read out the state of the keys. Period of the polling needs to
be configured by the poll-interval DT property.
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
index c6fbcdf..5b37be0 100644
--- a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
+++ b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
@@ -17,6 +17,10 @@
allOf:
- $ref: input.yaml#
+anyOf:
+ - required: [ interrupts ]
+ - required: [ poll-interval ]
+
properties:
compatible:
const: fsl,mpr121-touchkey
@@ -41,12 +45,12 @@
required:
- compatible
- reg
- - interrupts
- vdd-supply
- linux,keycodes
examples:
- |
+ // Example with interrupts
#include "dt-bindings/input/input.h"
i2c {
#address-cells = <1>;
@@ -64,3 +68,22 @@
<KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
};
};
+
+ - |
+ // Example with polling
+ #include "dt-bindings/input/input.h"
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ mpr121@5a {
+ compatible = "fsl,mpr121-touchkey";
+ reg = <0x5a>;
+ poll-interval = <20>;
+ autorepeat;
+ vdd-supply = <&ldo4_reg>;
+ linux,keycodes = <KEY_0>, <KEY_1>, <KEY_2>, <KEY_3>,
+ <KEY_4>, <KEY_5>, <KEY_6>, <KEY_7>,
+ <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/input/input.yaml b/Documentation/devicetree/bindings/input/input.yaml
index ca8fe84..6d51904 100644
--- a/Documentation/devicetree/bindings/input/input.yaml
+++ b/Documentation/devicetree/bindings/input/input.yaml
@@ -24,6 +24,10 @@
minimum: 0
maximum: 0xff
+ poll-interval:
+ description: Poll interval time in milliseconds.
+ $ref: /schemas/types.yaml#/definitions/uint32
+
power-off-time-sec:
description:
Duration in seconds which the key should be kept pressed for device to
diff --git a/drivers/input/keyboard/mpr121_touchkey.c b/drivers/input/keyboard/mpr121_touchkey.c
index ee80de4..40d6e50 100644
--- a/drivers/input/keyboard/mpr121_touchkey.c
+++ b/drivers/input/keyboard/mpr121_touchkey.c
@@ -54,6 +54,9 @@
/* MPR121 has 12 keys */
#define MPR121_MAX_KEY_COUNT 12
+#define MPR121_MIN_POLL_INTERVAL 10
+#define MPR121_MAX_POLL_INTERVAL 200
+
struct mpr121_touchkey {
struct i2c_client *client;
struct input_dev *input_dev;
@@ -115,11 +118,11 @@
return vdd_supply;
}
-static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+static void mpr_touchkey_report(struct input_dev *dev)
{
- struct mpr121_touchkey *mpr121 = dev_id;
- struct i2c_client *client = mpr121->client;
+ struct mpr121_touchkey *mpr121 = input_get_drvdata(dev);
struct input_dev *input = mpr121->input_dev;
+ struct i2c_client *client = mpr121->client;
unsigned long bit_changed;
unsigned int key_num;
int reg;
@@ -127,14 +130,14 @@
reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
if (reg < 0) {
dev_err(&client->dev, "i2c read error [%d]\n", reg);
- goto out;
+ return;
}
reg <<= 8;
reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
if (reg < 0) {
dev_err(&client->dev, "i2c read error [%d]\n", reg);
- goto out;
+ return;
}
reg &= TOUCH_STATUS_MASK;
@@ -155,8 +158,14 @@
}
input_sync(input);
+}
-out:
+static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+{
+ struct mpr121_touchkey *mpr121 = dev_id;
+
+ mpr_touchkey_report(mpr121->input_dev);
+
return IRQ_HANDLED;
}
@@ -229,14 +238,10 @@
int vdd_uv;
struct mpr121_touchkey *mpr121;
struct input_dev *input_dev;
+ u32 poll_interval = 0;
int error;
int i;
- if (!client->irq) {
- dev_err(dev, "irq number should not be zero\n");
- return -EINVAL;
- }
-
vdd_supply = mpr121_vdd_supply_init(dev);
if (IS_ERR(vdd_supply))
return PTR_ERR(vdd_supply);
@@ -274,6 +279,7 @@
if (device_property_read_bool(dev, "autorepeat"))
__set_bit(EV_REP, input_dev->evbit);
input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+ input_set_drvdata(input_dev, mpr121);
input_dev->keycode = mpr121->keycodes;
input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
@@ -288,13 +294,40 @@
return error;
}
- error = devm_request_threaded_irq(dev, client->irq, NULL,
- mpr_touchkey_interrupt,
- IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
- dev->driver->name, mpr121);
- if (error) {
- dev_err(dev, "Failed to register interrupt\n");
- return error;
+ device_property_read_u32(dev, "poll-interval", &poll_interval);
+
+ if (client->irq) {
+ error = devm_request_threaded_irq(dev, client->irq, NULL,
+ mpr_touchkey_interrupt,
+ IRQF_TRIGGER_FALLING |
+ IRQF_ONESHOT,
+ dev->driver->name, mpr121);
+ if (error) {
+ dev_err(dev, "Failed to register interrupt\n");
+ return error;
+ }
+ } else if (poll_interval) {
+ if (poll_interval < MPR121_MIN_POLL_INTERVAL)
+ return -EINVAL;
+
+ if (poll_interval > MPR121_MAX_POLL_INTERVAL)
+ return -EINVAL;
+
+ error = input_setup_polling(input_dev, mpr_touchkey_report);
+ if (error) {
+ dev_err(dev, "Failed to setup polling\n");
+ return error;
+ }
+
+ input_set_poll_interval(input_dev, poll_interval);
+ input_set_min_poll_interval(input_dev,
+ MPR121_MIN_POLL_INTERVAL);
+ input_set_max_poll_interval(input_dev,
+ MPR121_MAX_POLL_INTERVAL);
+ } else {
+ dev_err(dev,
+ "invalid IRQ number and polling not configured\n");
+ return -EINVAL;
}
error = input_register_device(input_dev);
