input: keyboard: rk_keys: Add support for configuring adc drift value from DT

If the adc drift value is 70, some keys maybe report twice, because
the range of adc_value +/-70 is overlapping other keys' adc range.
So it is better configuring adc drift value from DT, that also can
support more keys at a adc channel. The default adc drift value is
70, if it does not get the drift value from DT.

Change-Id: I46cef235094116d4f03af5e5c0cd3a6dfe7e8b0d
Signed-off-by: David Wu <david.wu@rock-chips.com>

diff --git a/drivers/input/keyboard/rk_keys.c b/drivers/input/keyboard/rk_keys.c
old mode 100755 (executable)
new mode 100644 (file)
index 8e502ee..9d7e3e3
--- a/drivers/input/keyboard/rk_keys.c
+++ b/drivers/input/keyboard/rk_keys.c
@@ -36,11 +36,11 @@
 #include <linux/of_gpio.h>
 #include <linux/of_platform.h>
 
-#define EMPTY_ADVALUE                  950
-#define DRIFT_ADVALUE                  70
+#define EMPTY_DEFAULT_ADVALUE          1024
+#define DRIFT_DEFAULT_ADVALUE          70
 #define INVALID_ADVALUE                        -1
-#define EV_ENCALL                       KEY_F4
-#define EV_MENU                         KEY_F1
+#define EV_ENCALL                      KEY_F4
+#define EV_MENU                                KEY_F1
 
 #if 0
 #define key_dbg(bdata, format, arg...)         \
@@ -78,6 +78,7 @@ struct rk_keys_drvdata {
        bool in_suspend;
        int result;
        int rep;
+       int drift_advalue;
        struct wake_lock wake_lock;
        struct input_dev *input;
        struct delayed_work adc_poll_work;
@@ -204,15 +205,16 @@ static void adc_key_poll(struct work_struct *work)
        ddata = container_of(work, struct rk_keys_drvdata, adc_poll_work.work);
        if (!ddata->in_suspend) {
                result = rk_key_adc_iio_read(ddata);
-               if (result > INVALID_ADVALUE && result < EMPTY_ADVALUE)
+               if (result > INVALID_ADVALUE &&
+                   result < (EMPTY_DEFAULT_ADVALUE - ddata->drift_advalue))
                        ddata->result = result;
                for (i = 0; i < ddata->nbuttons; i++) {
                        struct rk_keys_button *button = &ddata->button[i];
 
                        if (!button->adc_value)
                                continue;
-                       if (result < button->adc_value + DRIFT_ADVALUE &&
-                           result > button->adc_value - DRIFT_ADVALUE)
+                       if (result < button->adc_value + ddata->drift_advalue &&
+                           result > button->adc_value - ddata->drift_advalue)
                                button->adc_state = 1;
                        else
                                button->adc_state = 0;
@@ -245,7 +247,12 @@ static int rk_keys_parse_dt(struct rk_keys_drvdata *pdata,
        struct device_node *child_node;
        struct iio_channel *chan;
        int ret, gpio, i = 0;
-       u32 code, adc_value, flags;
+       u32 code, adc_value, flags, drift;
+
+       if (of_property_read_u32(node, "adc-drift", &drift))
+               pdata->drift_advalue = DRIFT_DEFAULT_ADVALUE;
+       else
+               pdata->drift_advalue = (int)drift;
 
        chan = iio_channel_get(&pdev->dev, NULL);
        if (IS_ERR(chan)) {