ltr502als.c: Port patches from GB

BZ: 17031

This patch inclues fixing for the following bugs:
BZ 16176: Obviate incorrect PS interrupt
BZ 13626: Reduce intergation circles and enhance adc-lux conversion
BZ 10605: workaround for proximity sensor do not work on first boot issue
BZ 13733: Add GPL header in the code file

Change-Id: I81b73662115d421d7a002a79d096e8a87590ec4a
Signed-off-by: Leo Yan <leo.yan@intel.com>
Reviewed-on: http://android.intel.com:8080/27132
Reviewed-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: Du, Alek <alek.du@intel.com>
Reviewed-by: Koskinen, Ilkka <ilkka.koskinen@intel.com>
Tested-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/hwmon/ltr502als.c b/drivers/hwmon/ltr502als.c
index dd32bb6..321cf20 100644 (file)
--- a/drivers/hwmon/ltr502als.c
+++ b/drivers/hwmon/ltr502als.c
@@ -1,3 +1,17 @@
+/*
+ * Copyright (C) 2009 LITE-ON Technology Corp.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
@@ -70,7 +84,7 @@
 #define PRX_COUNT8             (2 << PRX_ACCURACY)
 #define PRX_COUNT9             (3 << PRX_ACCURACY)
 #define PRX_COUNT_MASK         0XC0
-#define PRX_THRESH_CTL         0
+#define PRX_THRESH_CTL         0x1F
 #define PRX_THRESH_MASK                0X1F
 
 #define DATAREG                        0x05
@@ -126,6 +140,11 @@ struct alsps_device {
 
 static struct alsps_device *alsps_dev; /* for miscdevice operations */
 
+static const int lux_map[] = { 0,      40,     100,    170,    330,    700,
+                               1600,   3000,   5000,   9000,   20000,  50000};
+static const int adc_map[] = { 0,      3,      5,      10,     15,     20,
+                               25,     30,     35,     40,     45,     50};
+
 #define ALSPS_PROXIMITY_DATA_READY      0
 #define ALSPS_AMBIENT_DATA_READY        1
 #define ALSPS_PROXIMITY_FIRST_POLL      2
@@ -157,19 +176,23 @@ static int alsps_write(struct alsps_device *alsps, u8 reg, u8 val)
 static int ambient_get_lum(int adc)
 {
        int i = 0;
-       int convert_lux[] = {   0,      40,     100,    170,    330,    700,
-                               1600,   3000,   5000,   9000,   20000,  50000};
-       int convert_adc[] = {   0,      3,      5,      10,     15,     20,
-                               25,     30,     35,     40,     45,     50};
+       int lux;
 
        do {
-               if (adc <= convert_adc[i])
+               if (adc <= adc_map[i])
                        break;
                i++;
-       } while (i < ARRAY_SIZE(convert_adc) - 1);
+       } while (i < ARRAY_SIZE(adc_map) - 1);
+
+       if (i == 0 || i == ARRAY_SIZE(adc_map) - 1)
+               lux = lux_map[i];
+       else
+               lux = lux_map[i - 1] +
+                       (lux_map[i] - lux_map[i - 1]) * (adc - adc_map[i - 1]) /
+                       (adc_map[i] - adc_map[i - 1]);
 
-       pr_debug("adc = %d , lux = %d", adc, convert_lux[i]);
-       return convert_lux[i];
+       pr_debug("adc = %d , lux = %d", adc, lux);
+       return lux;
 }
 
 static ssize_t proximity_read(struct file *filep,
@@ -290,7 +313,7 @@ static ssize_t ambient_read(struct file *filep,
        client = filep->private_data;
        mutex_lock(&alsps_dev->lock);
        if (alsps_dev->alsps_switch & AMBIENT_ENABLE) {
-               lumen = ambient_get_lum(ambient_sta->now);
+               lumen = ambient_get_lum(ambient_sta->once);
                ret = sizeof(lumen);
 
                clear_bit(ALSPS_AMBIENT_DATA_READY, &client->status);
@@ -382,9 +405,12 @@ static int ltr502als_initchip(struct alsps_device *alsps)
        alsps_write(alsps, TCREG,
                    PRX_INT_CYCLE1 | INTEGRATE_100MS | ALPS_INT_CYCLE4);
 
-       /* change proximity threshold to 18 */
+       /* change proximity threshold PRX_THRESH_CTL to 31 to decrease the distance
+        * that triggers proximity interrupt*/
        alsps_read(alsps, DPSCTROL, &val);
-       alsps_write(alsps, DPSCTROL, (val & PRX_COUNT_MASK) | 0x12);
+       alsps_write(alsps, DPSCTROL, (val & PRX_COUNT_MASK) | PRX_THRESH_CTL);
+
+       alsps_write(alsps, CONFIGREG, POWER_DOWN);
 
        return 0;
 }
@@ -451,6 +477,7 @@ static void ltr502_mode(struct alsps_client *client, int mode)
                        break;
                alsps_dev->ambient_count++;
                alsps_dev->alsps_switch |= AMBIENT_ENABLE;
+               alsps_dev->als_state.once = 0;
                break;
        default:
                break;