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Date: Thu, 13 Jun 2013 20:20:46 +0200
From: Andi Shyti <andi@...zian.org>
To: arnd@...db.de, gregkh@...uxfoundation.org
Cc: linux-kernel@...r.kernel.org, pc@...f.org, oatilla@...il.com,
andi@...zian.org
Subject: [PATCH 12/19] bh1770glc: Introduced dynamic threshold
From: Onur Atilla <oatilla@...il.com>
Added dynamic threshold capability to the driver and removed
constant threshold value setting, thresh_above1_value, from
the sysfs interface.
Only one threshold value is visible and configurable through
the sysfs interface now; it is prox0_threshold_value. According
to the actual status of the proximity interrupt, the threshold
is set dynamically using a newly introduced hysteresis value.
Hysteresis is a configurable parameter.
Signed-off-by: Onur Atilla <oatilla@...il.com>
Signed-off-by: Andi Shyti <andi@...zian.org>
---
drivers/misc/bh1770glc.c | 96 +++++++++++++++++++++++++----------------
include/linux/i2c/bh1770glc.h | 3 ++
2 files changed, 61 insertions(+), 38 deletions(-)
diff --git a/drivers/misc/bh1770glc.c b/drivers/misc/bh1770glc.c
index eec799e..fe49964 100644
--- a/drivers/misc/bh1770glc.c
+++ b/drivers/misc/bh1770glc.c
@@ -165,8 +165,10 @@ struct bh1770_chip {
u8 prox_persistence_counter;
u8 prox_data;
u8 prox_threshold;
+ u8 prox_calib_threshold;
+ u8 prox_min_threshold;
+ u8 prox_hysteresis;
bool prox_force_update;
- u8 prox_abs_thres;
u8 prox_led;
struct input_dev *input_dev;
@@ -476,25 +478,45 @@ static int bh1770_prox_read_result(struct bh1770_chip *chip)
else
above = false;
- /* Strong proximity level or force mode requires immediate response */
- if (chip->prox_data >= chip->prox_abs_thres ||
- chip->prox_force_update)
+ /* Forced mode requires immediate response */
+ if (chip->prox_force_update)
chip->prox_persistence_counter = chip->prox_persistence;
chip->prox_force_update = false;
- /* Persistence filttering to reduce false proximity events */
+ /* Persistence filtering to reduce false proximity events */
if (likely(above)) {
if (chip->prox_persistence_counter < chip->prox_persistence) {
chip->prox_persistence_counter++;
ret = -ENODATA;
} else {
mode = PROX_ABOVE_THRESHOLD;
+
+ /*
+ * When above the threshold, reset the threshold value
+ * to a lower value defined by the given hysteresis
+ * The lowest value allowed is the min value
+ **/
+ if ((chip->prox_calib_threshold - chip->prox_hysteresis)
+ >= chip->prox_min_threshold) {
+ chip->prox_threshold =
+ chip->prox_calib_threshold -
+ chip->prox_hysteresis;
+ bh1770_prox_set_threshold(chip);
+ }
+ chip->prox_persistence_counter = 0;
ret = 0;
}
} else {
chip->prox_persistence_counter = 0;
mode = PROX_BELOW_THRESHOLD;
+
+ /*
+ * When below the threshold, reset the threshold value
+ * to the calibration value
+ */
+ chip->prox_threshold = chip->prox_calib_threshold;
+ bh1770_prox_set_threshold(chip);
ret = 0;
}
@@ -528,11 +550,20 @@ static int bh1770_detect(struct bh1770_chip *chip)
chip->prox_coef = BH1770_COEF_SCALER;
chip->prox_const = 0;
chip->lux_cf = BH1770_NEUTRAL_CF;
+ chip->prox_min_threshold = BH1770_PROX_DEF_THRES;
if ((manu == BH1770_MANUFACT_ROHM) &&
((part & BH1770_PART_MASK) == BH1770_PART)) {
snprintf(chip->chipname, sizeof(chip->chipname), "BH1770GLC");
chip->lux_cf = chip->pdata->als_scf_BH1770;
+
+ /* apply minimum threshold value only after verifying it */
+ if ((chip->pdata->prox_min_thresh_BH1770 > 0) &&
+ (chip->pdata->prox_min_thresh_BH1770 <
+ BH1770_PROX_RANGE)) {
+ chip->prox_min_threshold =
+ chip->pdata->prox_min_thresh_BH1770;
+ }
return 0;
}
@@ -540,6 +571,14 @@ static int bh1770_detect(struct bh1770_chip *chip)
((part & BH1770_PART_MASK) == BH1770_PART)) {
snprintf(chip->chipname, sizeof(chip->chipname), "SFH7770");
chip->lux_cf = chip->pdata->als_scf_SFH7770;
+
+ /* apply minimum threshold value only after verifying it */
+ if ((chip->pdata->prox_min_thresh_SFH7770 > 0) &&
+ (chip->pdata->prox_min_thresh_SFH7770 <
+ BH1770_PROX_RANGE)) {
+ chip->prox_min_threshold =
+ chip->pdata->prox_min_thresh_SFH7770;
+ }
return 0;
}
@@ -929,6 +968,8 @@ static ssize_t bh1770_set_prox_thres(struct device *dev,
mutex_unlock(&chip->mutex);
if (ret < 0)
return ret;
+ /* Remember the calibrated threshold value */
+ chip->prox_calib_threshold = chip->prox_threshold;
return count;
}
@@ -958,31 +999,6 @@ static ssize_t bh1770_prox_persistence_store(struct device *dev,
return len;
}
-static ssize_t bh1770_prox_abs_thres_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct bh1770_chip *chip = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", chip->prox_abs_thres);
-}
-
-static ssize_t bh1770_prox_abs_thres_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- struct bh1770_chip *chip = dev_get_drvdata(dev);
- unsigned long value;
-
- if (kstrtoul(buf, 0, &value))
- return -EINVAL;
-
- if (value > BH1770_PROX_RANGE)
- return -EINVAL;
-
- chip->prox_abs_thres = value;
-
- return len;
-}
-
static ssize_t bh1770_chip_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1162,10 +1178,7 @@ static ssize_t bh1770_set_lux_thresh_below(struct device *dev,
static DEVICE_ATTR(prox0_raw_en, S_IRUGO | S_IWUSR, bh1770_prox_enable_show,
bh1770_prox_enable_store);
-static DEVICE_ATTR(prox0_thresh_above1_value, S_IRUGO | S_IWUSR,
- bh1770_prox_abs_thres_show,
- bh1770_prox_abs_thres_store);
-static DEVICE_ATTR(prox0_thresh_above0_value, S_IRUGO | S_IWUSR,
+static DEVICE_ATTR(prox0_threshold_value, S_IRUGO | S_IWUSR,
bh1770_get_prox_thres,
bh1770_set_prox_thres);
static DEVICE_ATTR(prox0_raw, S_IRUGO, bh1770_prox_result_show, NULL);
@@ -1225,8 +1238,7 @@ static struct attribute *sysfs_attrs[] = {
&dev_attr_prox0_rate_above.attr,
&dev_attr_prox0_rate_below.attr,
&dev_attr_prox0_rate_avail.attr,
- &dev_attr_prox0_thresh_above0_value.attr,
- &dev_attr_prox0_thresh_above1_value.attr,
+ &dev_attr_prox0_threshold_value.attr,
&dev_attr_chip_id.attr,
&dev_attr_power_state.attr,
NULL
@@ -1270,13 +1282,18 @@ static int bh1770_probe(struct i2c_client *client,
else
chip->lux_ga = chip->pdata->glass_attenuation;
- chip->prox_threshold = BH1770_PROX_DEF_THRES;
chip->prox_led = chip->pdata->led_def_curr;
- chip->prox_abs_thres = BH1770_PROX_DEF_ABS_THRES;
chip->prox_persistence = BH1770_DEFAULT_PERSISTENCE;
chip->prox_rate_threshold = BH1770_PROX_DEF_RATE_THRESH;
chip->prox_rate = BH1770_PROX_DEFAULT_RATE;
chip->prox_data = 0;
+ /* Make sure that the given hysteresis value is in range */
+ if ((chip->pdata->prox_hysteresis > BH1770_PROX_RANGE) ||
+ (chip->pdata->prox_hysteresis < 0)) {
+ chip->prox_hysteresis = 0;
+ } else {
+ chip->prox_hysteresis = chip->pdata->prox_hysteresis;
+ }
chip->regs[0].supply = reg_vcc;
chip->regs[1].supply = reg_vleds;
@@ -1300,6 +1317,9 @@ static int bh1770_probe(struct i2c_client *client,
if (err < 0)
goto fail3;
+ chip->prox_threshold = chip->prox_min_threshold;
+ chip->prox_calib_threshold = chip->prox_threshold;
+
/* Start chip */
bh1770_chip_on(chip);
pm_runtime_set_active(&client->dev);
diff --git a/include/linux/i2c/bh1770glc.h b/include/linux/i2c/bh1770glc.h
index a08060a..ed670dd 100644
--- a/include/linux/i2c/bh1770glc.h
+++ b/include/linux/i2c/bh1770glc.h
@@ -49,6 +49,9 @@ struct bh1770_platform_data {
__u32 glass_attenuation;
__u32 als_scf_BH1770;
__u32 als_scf_SFH7770;
+ u8 prox_hysteresis;
+ u8 prox_min_thresh_BH1770;
+ u8 prox_min_thresh_SFH7770;
int (*setup_resources)(void);
int (*release_resources)(void);
};
--
1.7.10.4
--
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