ltr502als.c: Modify the way of ALS first data reporting

BZ: 17876 18551

1. Previously, when ALS is enabled, it will report zero before the first
interrupt occurs, this may cause incorrect behavior of LED light.  Now
ALS doesn't report any data until the first interrupt occurs.
2. In order to speed up the interrupt triggering, ADC sample integration
circle of ALS is changed to 1.

Signed-off-by: Leo Yan <leo.yan@intel.com>
Change-Id: I25a2d16e9db09cc44a299b127feff8a3f53d4430
Reviewed-on: http://android.intel.com:8080/29959
Reviewed-by: Yan, Leo <leo.yan@intel.com>
Reviewed-by: Liu, Hong <hong.liu@intel.com>
Reviewed-by: Du, Alek <alek.du@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 c240b80..b4f2ee3 100644 (file)
--- a/drivers/hwmon/ltr502als.c
+++ b/drivers/hwmon/ltr502als.c
@@ -105,6 +105,10 @@
 #define PS_MODE_DISABLE                2
 #define PS_MODE_ENABLE         3
 
+/* it takes about 650ms to generate the first interrupt when ALS is enabled*/
+#define ALS_FIRST_INT_DELAY    650
+#define ALS_INIT_DATA          0xffff
+
 struct alsps_client {
        struct list_head list;
        unsigned long status;
@@ -129,6 +133,7 @@ struct alsps_device {
                                       * variables, lists and registers
                                       */
 
+       struct delayed_work     als_first_work;
        struct list_head        proximity_list;
        struct list_head        ambient_list;
 
@@ -145,12 +150,12 @@ static const int lux_map[] = {    0,      40,     100,    170,    330,    700,
 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
-#define ALSPS_AMBIENT_FIRST_POLL        3
-#define ALSPS_PROXIMITY_IOCTL_ENABLE    4
-#define ALSPS_AMBIENT_IOCTL_ENABLE      5
+#define PS_DATA_READY      0
+#define ALS_DATA_READY     1
+#define PS_FIRST_POLL      2
+#define ALS_FIRST_POLL     3
+#define PS_IOCTL_ENABLE    4
+#define ALS_IOCTL_ENABLE   5
 
 static int alsps_read(struct alsps_device *alsps, u8 reg, u8 *pval)
 {
@@ -206,7 +211,7 @@ static ssize_t proximity_read(struct file *filep,
        mutex_lock(&alsps_dev->lock);
        if (alsps_dev->alsps_switch & PROXIMITY_ENABLE) {
                ret = sizeof(ps_state->once);
-               clear_bit(ALSPS_PROXIMITY_DATA_READY, &client->status);
+               clear_bit(PS_DATA_READY, &client->status);
                if (copy_to_user(buffer, &ps_state->once,
                                 sizeof(ps_state->once))) {
                        ret = -EFAULT;
@@ -225,12 +230,12 @@ proximity_poll(struct file *filep, struct poll_table_struct *wait)
 
        poll_wait(filep, &alsps_dev->proximity_workq_head, wait);
 
-       if (test_bit(ALSPS_PROXIMITY_FIRST_POLL, &client->status)) {
+       if (test_bit(PS_FIRST_POLL, &client->status)) {
                mask |= (POLLIN | POLLRDNORM);
-               clear_bit(ALSPS_PROXIMITY_FIRST_POLL, &client->status);
+               clear_bit(PS_FIRST_POLL, &client->status);
        }
 
-       if (test_bit(ALSPS_PROXIMITY_DATA_READY, &client->status))
+       if (test_bit(PS_DATA_READY, &client->status))
                mask |= (POLLIN | POLLRDNORM);
 
        return mask;
@@ -273,7 +278,7 @@ static void proximity_handle_irq(struct alsps_device *alsps, u8 reg_data)
                alsps->ps_state.once = alsps->ps_state.now;
 
                list_for_each_entry(client, &alsps->proximity_list, list)
-                       set_bit(ALSPS_PROXIMITY_DATA_READY, &client->status);
+                       set_bit(PS_DATA_READY, &client->status);
 
                wake_up(&alsps->proximity_workq_head);
        }
@@ -297,7 +302,7 @@ static void ambient_handle_irq(struct alsps_device *alsps, u8 reg_data)
                alsps->als_state.once = alsps->als_state.now;
 
                list_for_each_entry(client, &alsps->ambient_list, list)
-                       set_bit(ALSPS_AMBIENT_DATA_READY, &client->status);
+                       set_bit(ALS_DATA_READY, &client->status);
 
                wake_up(&alsps->ambient_workq_head);
        }
@@ -316,7 +321,7 @@ static ssize_t ambient_read(struct file *filep,
                lumen = ambient_get_lum(ambient_sta->once);
                ret = sizeof(lumen);
 
-               clear_bit(ALSPS_AMBIENT_DATA_READY, &client->status);
+               clear_bit(ALS_DATA_READY, &client->status);
                if (copy_to_user(buffer, &lumen, sizeof(lumen)))
                        ret = -EFAULT;
        }
@@ -333,12 +338,12 @@ ambient_poll(struct file *filep, struct poll_table_struct *wait)
 
        poll_wait(filep, &alsps_dev->ambient_workq_head, wait);
 
-       if (test_bit(ALSPS_AMBIENT_FIRST_POLL, &client->status)) {
+       if (test_bit(ALS_FIRST_POLL, &client->status)) {
                mask |= (POLLIN | POLLRDNORM);
-               clear_bit(ALSPS_AMBIENT_FIRST_POLL, &client->status);
+               clear_bit(ALS_FIRST_POLL, &client->status);
        }
 
-       if (test_bit(ALSPS_AMBIENT_DATA_READY, &client->status))
+       if (test_bit(ALS_DATA_READY, &client->status))
                mask |= (POLLIN | POLLRDNORM);
 
        return mask;
@@ -402,8 +407,9 @@ static int ltr502als_initchip(struct alsps_device *alsps)
        u8 val;
 
        alsps_write(alsps, CONFIGREG, POWER_UP | IDLE);
+       alsps_write(alsps, DLSCTROL, ADC_64LEVEL);
        alsps_write(alsps, TCREG,
-                   PRX_INT_CYCLE1 | INTEGRATE_100MS | ALPS_INT_CYCLE4);
+                   PRX_INT_CYCLE1 | INTEGRATE_100MS | ALPS_INT_CYCLE1);
 
        /* change proximity threshold PRX_THRESH_CTL to 31 to decrease the distance
         * that triggers proximity interrupt*/
@@ -435,6 +441,13 @@ static void ltr502_switch(int mode)
                break;
        }
        alsps_write(alsps_dev, CONFIGREG, data);
+
+       if (mode & AMBIENT_ENABLE) {
+               alsps_dev->als_state.once = ALS_INIT_DATA;
+               schedule_delayed_work(&alsps_dev->als_first_work,
+                               msecs_to_jiffies(ALS_FIRST_INT_DELAY));
+       } else if (alsps_dev->alsps_switch & AMBIENT_ENABLE)
+               cancel_delayed_work(&alsps_dev->als_first_work);
 }
 
 /* lock must be held when calling this function */
@@ -444,7 +457,11 @@ static void ltr502_mode(struct alsps_client *client, int mode)
 
        switch (mode) {
        case PS_MODE_DISABLE:
-               clear_bit(ALSPS_PROXIMITY_IOCTL_ENABLE, &client->status);
+               if (!test_and_clear_bit(PS_IOCTL_ENABLE, &client->status)) {
+                       dev_dbg(&alsps_dev->client->dev,
+                               "PS is not enabled for this client\n");
+                               return;
+               }
                if (--alsps_dev->proximity_count <= 0) {
                        alsps_dev->proximity_count = 0;
                        alsps_dev->alsps_switch &= ~PROXIMITY_ENABLE;
@@ -452,32 +469,33 @@ static void ltr502_mode(struct alsps_client *client, int mode)
                break;
        case PS_MODE_ENABLE:
                list_for_each_entry(list_tmp, &alsps_dev->proximity_list, list)
-                       set_bit(ALSPS_PROXIMITY_FIRST_POLL, &list_tmp->status);
+                       set_bit(PS_FIRST_POLL, &list_tmp->status);
 
-               if (test_and_set_bit(ALSPS_PROXIMITY_IOCTL_ENABLE,
-                                       &client->status))
-                       break;
+               if (test_and_set_bit(PS_IOCTL_ENABLE, &client->status))
+                       return;
                alsps_dev->proximity_count++;
                alsps_dev->alsps_switch |= PROXIMITY_ENABLE;
                alsps_dev->ps_state.once = 0;
                break;
        case ALS_MODE_DISABLE:
-               clear_bit(ALSPS_AMBIENT_IOCTL_ENABLE, &client->status);
+               if (!test_and_clear_bit(ALS_IOCTL_ENABLE, &client->status)) {
+                       dev_dbg(&alsps_dev->client->dev,
+                               "ALS is not enabled for this client\n");
+                               return;
+               }
                if (--alsps_dev->ambient_count <= 0) {
                        alsps_dev->ambient_count = 0;
                        alsps_dev->alsps_switch &= ~AMBIENT_ENABLE;
                }
                break;
        case ALS_MODE_ENABLE:
-               list_for_each_entry(list_tmp, &alsps_dev->ambient_list, list)
-                       set_bit(ALSPS_AMBIENT_FIRST_POLL, &list_tmp->status);
-
-               if (test_and_set_bit(ALSPS_AMBIENT_IOCTL_ENABLE,
-                                       &client->status))
-                       break;
-               alsps_dev->ambient_count++;
+               if (test_and_set_bit(ALS_IOCTL_ENABLE, &client->status) ||
+                               alsps_dev->ambient_count++ > 0) {
+                       if (alsps_dev->als_state.once != ALS_INIT_DATA)
+                               set_bit(ALS_FIRST_POLL, &client->status);
+                       return;
+               }
                alsps_dev->alsps_switch |= AMBIENT_ENABLE;
-               alsps_dev->als_state.once = 0;
                break;
        default:
                break;
@@ -542,7 +560,7 @@ static int ambient_close(struct inode *inode, struct file *filep)
        mutex_lock(&alsps_dev->lock);
        list_del(&client->list);
 
-       if (test_bit(ALSPS_AMBIENT_IOCTL_ENABLE, &client->status))
+       if (test_bit(ALS_IOCTL_ENABLE, &client->status))
                ltr502_mode(client, ALS_MODE_DISABLE);
        mutex_unlock(&alsps_dev->lock);
        kfree(client);
@@ -558,7 +576,7 @@ static int proximity_close(struct inode *inode, struct file *filep)
        mutex_lock(&alsps_dev->lock);
        list_del(&client->list);
 
-       if (test_bit(ALSPS_PROXIMITY_IOCTL_ENABLE, &client->status))
+       if (test_bit(PS_IOCTL_ENABLE, &client->status))
                ltr502_mode(client, PS_MODE_DISABLE);
        mutex_unlock(&alsps_dev->lock);
        kfree(client);
@@ -643,7 +661,7 @@ static int ltr502als_suspend(struct device *dev)
                goto fail;
 
        list_for_each_entry(client, &alsps_dev->proximity_list, list)
-               if (test_bit(ALSPS_PROXIMITY_DATA_READY, &client->status))
+               if (test_bit(PS_DATA_READY, &client->status))
                        goto fail_unlock;
 
        mutex_unlock(&alsps_dev->lock);
@@ -665,6 +683,23 @@ static int ltr502als_resume(struct device *dev)
        return 0;
 }
 
+static void als_avoid_slience(struct work_struct *work)
+{
+       u8 data;
+       struct alsps_device *alsps = container_of((struct delayed_work *)work,
+                       struct alsps_device, als_first_work);
+
+       mutex_lock(&alsps->lock);
+       if (alsps->als_state.once == ALS_INIT_DATA) {
+               dev_dbg(&alsps->client->dev, "%s: als_state.once=%d\n",
+                               __func__, alsps->als_state.once);
+               alsps_read(alsps, DATAREG, &data);
+               ambient_handle_irq(alsps, data);
+       }
+       mutex_unlock(&alsps->lock);
+}
+
+
 static struct alsps_device *ltr502als_alloc_dev(void)
 {
        struct alsps_device *alsps;
@@ -678,6 +713,8 @@ static struct alsps_device *ltr502als_alloc_dev(void)
 
        INIT_LIST_HEAD(&alsps->ambient_list);
        INIT_LIST_HEAD(&alsps->proximity_list);
+
+       INIT_DELAYED_WORK(&alsps->als_first_work, als_avoid_slience);
        mutex_init(&alsps->lock);
 
        return alsps;