lkml.org 
[lkml]   [2020]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH V3 4/4] backlight: qcom-wled: Update auto calibration support for WLED5
Date
Currently, auto calibration logic checks only for OVP_FAULT bit
to be set in FAULT_STATUS register to detect OVP fault. This works
well for WLED4 type. However, WLED5 type has OVP_PRE_ALARM bit
which can indicate a potential OVP fault. Use that as well for
detecting OVP fault and run auto calibration to fix the sink
configuration.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
drivers/video/backlight/qcom-wled.c | 90 ++++++++++++++++++++++++++++++++++++-
1 file changed, 88 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index edbbcb2..5079f1f 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -27,6 +27,7 @@
#define WLED3_CTRL_REG_ILIM_FAULT_BIT BIT(0)
#define WLED3_CTRL_REG_OVP_FAULT_BIT BIT(1)
#define WLED4_CTRL_REG_SC_FAULT_BIT BIT(2)
+#define WLED5_CTRL_REG_OVP_PRE_ALARM_BIT BIT(4)

#define WLED3_CTRL_REG_INT_RT_STS 0x10
#define WLED3_CTRL_REG_OVP_FAULT_STATUS BIT(1)
@@ -104,6 +105,10 @@

#define WLED4_SINK_REG_BRIGHT(n) (0x57 + (n * 0x10))

+/* WLED5 specific control registers */
+#define WLED5_CTRL_REG_OVP_INT_CTL 0x5f
+#define WLED5_CTRL_REG_OVP_INT_TIMER_MASK GENMASK(2, 0)
+
/* WLED5 specific sink registers */
#define WLED5_SINK_REG_MOD_A_EN 0x50
#define WLED5_SINK_REG_MOD_B_EN 0x60
@@ -394,11 +399,67 @@ static int wled4_ovp_fault_status(struct wled *wled, bool *fault_set)
return rc;
}

+static int wled5_ovp_fault_status(struct wled *wled, bool *fault_set)
+{
+ int rc;
+ u32 int_rt_sts, fault_sts;
+
+ *fault_set = false;
+ rc = regmap_read(wled->regmap,
+ wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS,
+ &int_rt_sts);
+ if (rc < 0) {
+ dev_err(wled->dev, "Failed to read INT_RT_STS rc=%d\n", rc);
+ return rc;
+ }
+
+ rc = regmap_read(wled->regmap,
+ wled->ctrl_addr + WLED3_CTRL_REG_FAULT_STATUS,
+ &fault_sts);
+ if (rc < 0) {
+ dev_err(wled->dev, "Failed to read FAULT_STATUS rc=%d\n", rc);
+ return rc;
+ }
+
+ if (int_rt_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS)
+ *fault_set = true;
+
+ if (fault_sts & (WLED3_CTRL_REG_OVP_FAULT_BIT |
+ WLED5_CTRL_REG_OVP_PRE_ALARM_BIT))
+ *fault_set = true;
+
+ if (*fault_set)
+ dev_dbg(wled->dev, "WLED OVP fault detected, int_rt_sts=0x%x fault_sts=0x%x\n",
+ int_rt_sts, fault_sts);
+
+ return rc;
+}
+
static int wled4_ovp_delay(struct wled *wled)
{
return WLED_SOFT_START_DLY_US;
}

+static int wled5_ovp_delay(struct wled *wled)
+{
+ int rc, delay_us;
+ u32 val;
+ u8 ovp_timer_ms[8] = {1, 2, 4, 8, 12, 16, 20, 24};
+
+ /* For WLED5, get the delay based on OVP timer */
+ rc = regmap_read(wled->regmap, wled->ctrl_addr +
+ WLED5_CTRL_REG_OVP_INT_CTL, &val);
+ if (rc < 0)
+ delay_us =
+ ovp_timer_ms[val & WLED5_CTRL_REG_OVP_INT_TIMER_MASK] * 1000;
+ else
+ delay_us = 2 * WLED_SOFT_START_DLY_US;
+
+ dev_dbg(wled->dev, "delay_time_us: %d\n", *delay_us);
+
+ return delay_us;
+}
+
static int wled_update_status(struct backlight_device *bl)
{
struct wled *wled = bl_get_data(bl);
@@ -736,9 +797,32 @@ static bool wled_auto_detection_required(struct wled *wled)
if (!wled->auto_detection_ovp_count) {
wled->start_ovp_fault_time = ktime_get();
wled->auto_detection_ovp_count++;
- } else {
+ return false;
+ }
+
+ if (wled->version == 5) {
+ /*
+ * WLED5 has OVP fault density interrupt configuration i.e. to
+ * count the number of OVP alarms for a certain duration before
+ * triggering OVP fault interrupt. By default, number of OVP
+ * fault events counted before an interrupt is fired is 32 and
+ * the time interval is 12 ms. If we see more than one OVP fault
+ * interrupt, then that should qualify for a real OVP fault
+ * condition to run auto calibration algorithm.
+ */
+
+ if (wled->auto_detection_ovp_count > 1) {
+ elapsed_time_us = ktime_us_delta(ktime_get(),
+ wled->start_ovp_fault_time);
+ wled->auto_detection_ovp_count = 0;
+ dev_dbg(wled->dev, "Elapsed time: %lld us\n",
+ elapsed_time_us);
+ return true;
+ }
+ wled->auto_detection_ovp_count++;
+ } else if (wled->version == 4) {
elapsed_time_us = ktime_us_delta(ktime_get(),
- wled->start_ovp_fault_time);
+ wled->start_ovp_fault_time);
if (elapsed_time_us > WLED_AUTO_DETECT_CNT_DLY_US)
wled->auto_detection_ovp_count = 0;
else
@@ -1424,6 +1508,8 @@ static int wled_configure(struct wled *wled)
wled->wled_set_brightness = wled5_set_brightness;
wled->wled_sync_toggle = wled5_sync_toggle;
wled->cabc_config = wled5_cabc_config;
+ wled->wled_ovp_fault_status = wled5_ovp_fault_status;
+ wled->wled_ovp_delay = wled5_ovp_delay;
wled->max_string_count = 4;

prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
\
 
 \ /
  Last update: 2020-03-09 14:27    [W:3.356 / U:1.788 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site