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 c6fbcdf7855612a9c1bd0e562865d1435e39bc30..5b37be0be4e927d297682085f7b00b99ec055b5b 100644 (file)
--- a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
+++ b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
@@ -17,6 +17,10 @@ description: |
 allOf:
   - $ref: input.yaml#
 
+anyOf:
+  - required: [ interrupts ]
+  - required: [ poll-interval ]
+
 properties:
   compatible:
     const: fsl,mpr121-touchkey
@@ -41,12 +45,12 @@ properties:
 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 @@ examples:
                              <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 ca8fe84a2e623f74a758161c8f54e33976de7eca..6d519046b3afc9de9822f3f85f865e7a52538890 100644 (file)
--- a/Documentation/devicetree/bindings/input/input.yaml
+++ b/Documentation/devicetree/bindings/input/input.yaml
@@ -24,6 +24,10 @@ properties:
           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 ee80de44ce3f6a49460655989027405c38b30a13..40d6e5087cdef060acce22fdd4aa2a5d082cf230 100644 (file)
--- 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 @@ static struct regulator *mpr121_vdd_supply_init(struct device *dev)
        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 @@ static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
        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 @@ static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
 
        }
        input_sync(input);
+}
+
+static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+{
+       struct mpr121_touchkey *mpr121 = dev_id;
+
+       mpr_touchkey_report(mpr121->input_dev);
 
-out:
        return IRQ_HANDLED;
 }
 
@@ -229,14 +238,10 @@ static int mpr_touchkey_probe(struct i2c_client *client,
        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 @@ static int mpr_touchkey_probe(struct i2c_client *client,
        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 @@ static int mpr_touchkey_probe(struct i2c_client *client,
                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);