leds: qpnp-wled: add stepper algorithm using brightness map
Add stepper algorithm support with dynamically calculated step
size or delay based on the brightness level change using the
brightness map table.
To help with running the algorithm efficiently, use a separate
workqueue with high priority to process the brightness levels.
Change-Id: Iea2a8da73b6bee3eaa7b28a12fd82c2a1507db99
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
diff --git a/drivers/leds/leds-qpnp-wled.c b/drivers/leds/leds-qpnp-wled.c
index 484c843..d2e576d 100644
--- a/drivers/leds/leds-qpnp-wled.c
+++ b/drivers/leds/leds-qpnp-wled.c
@@ -316,6 +316,7 @@
* @ cdev - led class device
* @ pdev - platform device
* @ work - worker for led operation
+ * @ wq - workqueue for setting brightness level
* @ lock - mutex lock for exclusive access
* @ fdbk_op - output feedback mode
* @ dim_mode - dimming mode
@@ -359,6 +360,7 @@
* @ disp_type_amoled - type of display: LCD/AMOLED
* @ en_ext_pfet_sc_pro - enable sc protection on external pfet
* @ prev_state - previous state of WLED
+ * @ stepper_en - Flag to enable stepper algorithm
* @ ovp_irq_disabled - OVP interrupt disable status
* @ auto_calib_enabled - Flag to enable auto calibration feature
* @ auto_calib_done - Flag to indicate auto calibration is done
@@ -371,6 +373,7 @@
struct regmap *regmap;
struct pmic_revid_data *pmic_rev_id;
struct work_struct work;
+ struct workqueue_struct *wq;
struct mutex lock;
struct mutex bus_lock;
enum qpnp_wled_fdbk_op fdbk_op;
@@ -415,6 +418,7 @@
bool disp_type_amoled;
bool en_ext_pfet_sc_pro;
bool prev_state;
+ bool stepper_en;
bool ovp_irq_disabled;
bool auto_calib_enabled;
bool auto_calib_done;
@@ -422,6 +426,21 @@
ktime_t start_ovp_fault_time;
};
+static int qpnp_wled_step_delay_us = 52000;
+module_param_named(
+ total_step_delay_us, qpnp_wled_step_delay_us, int, 0600
+);
+
+static int qpnp_wled_step_size_threshold = 3;
+module_param_named(
+ step_size_threshold, qpnp_wled_step_size_threshold, int, 0600
+);
+
+static int qpnp_wled_step_delay_gain = 2;
+module_param_named(
+ step_delay_gain, qpnp_wled_step_delay_gain, int, 0600
+);
+
/* helper to read a pmic register */
static int qpnp_wled_read_reg(struct qpnp_wled *wled, u16 addr, u8 *data)
{
@@ -583,6 +602,7 @@
return rc;
}
+ pr_debug("level:%d\n", level);
return 0;
}
@@ -613,6 +633,65 @@
return 0;
}
+static int qpnp_wled_set_step_level(struct qpnp_wled *wled, int new_level)
+{
+ int rc, i, num_steps, delay_us;
+ u16 level, start_level, end_level, step_size;
+ bool level_inc = false;
+
+ level = wled->prev_level;
+ start_level = wled->brt_map_table[level];
+ end_level = wled->brt_map_table[new_level];
+ level_inc = (new_level > level);
+
+ num_steps = abs(start_level - end_level);
+ if (!num_steps)
+ return 0;
+
+ delay_us = qpnp_wled_step_delay_us / num_steps;
+ pr_debug("level goes from [%d %d] num_steps: %d, delay: %d\n",
+ start_level, end_level, num_steps, delay_us);
+
+ if (delay_us < 500) {
+ step_size = 1000 / delay_us;
+ num_steps = num_steps / step_size;
+ delay_us = 1000;
+ } else {
+ if (num_steps < qpnp_wled_step_size_threshold)
+ delay_us *= qpnp_wled_step_delay_gain;
+
+ step_size = 1;
+ }
+
+ i = start_level;
+ while (num_steps--) {
+ if (level_inc)
+ i += step_size;
+ else
+ i -= step_size;
+
+ rc = qpnp_wled_set_level(wled, i);
+ if (rc < 0)
+ return rc;
+
+ if (delay_us > 0) {
+ if (delay_us < 20000)
+ usleep_range(delay_us, delay_us + 1);
+ else
+ msleep(delay_us / USEC_PER_MSEC);
+ }
+ }
+
+ if (i != end_level) {
+ i = end_level;
+ rc = qpnp_wled_set_level(wled, i);
+ if (rc < 0)
+ return rc;
+ }
+
+ return 0;
+}
+
static int qpnp_wled_psm_config(struct qpnp_wled *wled, bool enable)
{
int rc;
@@ -999,7 +1078,10 @@
level_255 = 255;
pr_debug("level: %d level_255: %d\n", level, level_255);
- rc = qpnp_wled_set_map_level(wled, level_255);
+ if (wled->stepper_en)
+ rc = qpnp_wled_set_step_level(wled, level_255);
+ else
+ rc = qpnp_wled_set_map_level(wled, level_255);
if (rc) {
dev_err(&wled->pdev->dev, "wled set level failed\n");
goto unlock_mutex;
@@ -1064,7 +1146,7 @@
level = wled->cdev.max_brightness;
wled->cdev.brightness = level;
- schedule_work(&wled->work);
+ queue_work(wled->wq, &wled->work);
}
static int qpnp_wled_set_disp(struct qpnp_wled *wled, u16 base_addr)
@@ -2226,6 +2308,8 @@
}
}
+ wled->stepper_en = of_property_read_bool(pdev->dev.of_node,
+ "qcom,wled-stepper-en");
wled->disp_type_amoled = of_property_read_bool(pdev->dev.of_node,
"qcom,disp-type-amoled");
if (wled->disp_type_amoled) {
@@ -2562,6 +2646,7 @@
}
wled->pmic_rev_id = get_revid_data(revid_node);
+ of_node_put(revid_node);
if (IS_ERR_OR_NULL(wled->pmic_rev_id)) {
pr_err("Unable to get pmic_revid rc=%ld\n",
PTR_ERR(wled->pmic_rev_id));
@@ -2576,6 +2661,12 @@
pr_debug("PMIC subtype %d Digital major %d\n",
wled->pmic_rev_id->pmic_subtype, wled->pmic_rev_id->rev4);
+ wled->wq = alloc_ordered_workqueue("qpnp_wled_wq", WQ_HIGHPRI);
+ if (!wled->wq) {
+ pr_err("Unable to alloc workqueue for WLED\n");
+ return -ENOMEM;
+ }
+
prop = of_get_address_by_name(pdev->dev.of_node, QPNP_WLED_SINK_BASE,
NULL, NULL);
if (!prop) {
@@ -2641,6 +2732,7 @@
led_classdev_unregister(&wled->cdev);
wled_register_fail:
cancel_work_sync(&wled->work);
+ destroy_workqueue(wled->wq);
mutex_destroy(&wled->lock);
return rc;
}
@@ -2656,6 +2748,7 @@
led_classdev_unregister(&wled->cdev);
cancel_work_sync(&wled->work);
+ destroy_workqueue(wled->wq);
mutex_destroy(&wled->lock);
return 0;