Re: [PATCH V1 2/5] backlight: qcom-wled: Add support for WLED4 peripheral
From: kgunda
Date: Thu May 17 2018 - 10:13:29 EST
On 2018-05-17 18:01, Rob Herring wrote:
On Thu, May 17, 2018 at 4:47 AM, <kgunda@xxxxxxxxxxxxxx> wrote:
On 2018-05-08 15:55, kgunda@xxxxxxxxxxxxxx wrote:
On 2018-05-07 21:50, Bjorn Andersson wrote:
On Thu 03 May 02:57 PDT 2018, Kiran Gunda wrote:
WLED4 peripheral is present on some PMICs like pmi8998
and pm660l. It has a different register map and also
configurations are different. Add support for it.
Several things are going on in this patch, it needs to be split to
not hide the functional changes from the structural/renames.
Ok. I will split it in the next series.
Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
---
.../bindings/leds/backlight/qcom-wled.txt | 172 ++++-
drivers/video/backlight/qcom-wled.c | 749
+++++++++++++++------
2 files changed, 696 insertions(+), 225 deletions(-)
diff --git
a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
index fb39e32..0ceffa1 100644
---
a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
+++
b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
@@ -1,30 +1,129 @@
Binding for Qualcomm Technologies, Inc. WLED driver
-Required properties:
-- compatible: should be "qcom,pm8941-wled"
-- reg: slave address
-
-Optional properties:
-- default-brightness: brightness value on boot, value from: 0-4095
- default: 2048
-- label: The name of the backlight device
-- qcom,cs-out: bool; enable current sink output
-- qcom,cabc: bool; enable content adaptive backlight control
-- qcom,ext-gen: bool; use externally generated modulator signal to
dim
-- qcom,current-limit: mA; per-string current limit; value from 0
to 25
- default: 20mA
-- qcom,current-boost-limit: mA; boost current limit; one of:
- 105, 385, 525, 805, 980, 1260, 1400, 1680
- default: 805mA
-- qcom,switching-freq: kHz; switching frequency; one of:
- 600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371,
- 1600, 1920, 2400, 3200, 4800, 9600,
- default: 1600kHz
-- qcom,ovp: V; Over-voltage protection limit; one of:
- 27, 29, 32, 35
- default: 29V
-- qcom,num-strings: #; number of led strings attached; value from
1 to
3
- default: 2
+WLED (White Light Emitting Diode) driver is used for controlling
display
+backlight that is part of PMIC on Qualcomm Technologies, Inc.
reference
+platforms. The PMIC is connected to the host processor via SPMI
bus.
+
+- compatible
+ Usage: required
+ Value type: <string>
+ Definition: should be "qcom,pm8941-wled" or
"qcom,pmi8998-wled".
+ or "qcom,pm660l-wled".
Better written as
should be one of:
X
Y
Z
Will do it in the next series.
+
+- reg
+ Usage: required
+ Value type: <prop encoded array>
+ Definition: Base address of the WLED modules.
+
+- interrupts
+ Usage: optional
+ Value type: <prop encoded array>
+ Definition: Interrupts associated with WLED. Interrupts
can be
+ specified as per the encoding listed under
+ Documentation/devicetree/bindings/spmi/
+ qcom,spmi-pmic-arb.txt.
Better to describe that this should be the "short" and "ovp"
interrupts
in this property than in the interrupt-names.
Ok. I will do it in the next series.
+
+- interrupt-names
+ Usage: optional
+ Value type: <string>
+ Definition: Interrupt names associated with the
interrupts.
+ Must be "short" and "ovp". The short circuit
detection
+ is not supported for PM8941.
+
+- label
+ Usage: required
+ Value type: <string>
+ Definition: The name of the backlight device
+
+- default-brightness
+ Usage: optional
+ Value type: <u32>
+ Definition: brightness value on boot, value from: 0-4095
+ Default: 2048
+
+- qcom,current-limit
+ Usage: optional
+ Value type: <u32>
+ Definition: uA; per-string current limit
You can't change unit on an existing property, that breaks any
existing
dts using the qcom,pm8941-wled compatible.
+ value:
+ For pm8941: from 0 to 25000 with 5000 ua step
+ Default 20000 uA
+ For pmi8998: from 0 to 30000 with 5000 ua
step
+ Default 25000 uA.
These values could be described just as well in mA, so keep the
original
unit - in particular since the boot-limit is in mA...
Ok. Will keep the original as is in the next series.
Here, I may have to go with the approach as in "qcom,ovp". Because for
pm8941
the current step is 1 mA (I have wrongly mentioned as 5000uA here) and
for
PMI8998
the current step is 2.5 mA. Hence, I will add another variable
"qcom,current-limit-ua"
just like "qcom,ovp-mv".
Use unit suffixes defined in bindings/property-units.txt.
Rob
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Thanks for pointing it ! hope I can use "qcom,current-limit-microamp"
and
"qcom,ovp-millivolt". I am asking this because i found only
"-microvolt".
"-millivolt" is not present in the bindings you pointed.