[PATCH V2 0/5] backlight: qcom-wled: Support for QCOM wled driver

[PATCH V2 0/5] backlight: qcom-wled: Support for QCOM wled driver

[Kiran Gunda]

This patch series renames the pm8941-wled.c driver to qcom-wled.c to add
the support for multiple PMICs supported by qualcomm. This patch series
supports both PM8941 and PMI8998 WLED. The PMI8998 WLED has the support
to handle the OVP (over voltage protection) and the SC (short circuit protection)
interrupts. It also has the auto calibration algorithm support to
configure the right strings if the user specified string configuration
is in-correct. These three features are added in this series for PMI8998.

changes from v1:
	Fixed the commit message for 
	backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

Kiran Gunda (5):
  backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c
  backlight: qcom-wled: Add support for WLED4 peripheral
  backlight: qcom-wled: Add support for short circuit handling
  backlight: qcom-wled: Add support for OVP interrupt handling
  backlight: qcom-wled: Add auto string detection logic

 .../bindings/leds/backlight/pm8941-wled.txt        |   42 -
 .../bindings/leds/backlight/qcom-wled.txt          |  158 +++
 drivers/video/backlight/Kconfig                    |    8 +-
 drivers/video/backlight/Makefile                   |    2 +-
 drivers/video/backlight/pm8941-wled.c              |  432 -------
 drivers/video/backlight/qcom-wled.c                | 1329 ++++++++++++++++++++
 6 files changed, 1492 insertions(+), 479 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
 delete mode 100644 drivers/video/backlight/pm8941-wled.c
 create mode 100644 drivers/video/backlight/qcom-wled.c

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

[PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[Kiran Gunda]

pm8941-wled.c driver is supporting the WLED peripheral
on pm8941. Rename it to qcom-wled.c so that it can support
WLED on multiple PMICs.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 +-
 drivers/video/backlight/Kconfig                                   | 8 ++++----
 drivers/video/backlight/Makefile                                  | 2 +-
 drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0
 4 files changed, 6 insertions(+), 6 deletions(-)
 rename Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt} (95%)
 rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)

diff --git a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
similarity index 95%
rename from Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
rename to Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
index e5b294d..fb39e32 100644
--- a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
+++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
@@ -1,4 +1,4 @@
-Binding for Qualcomm PM8941 WLED driver
+Binding for Qualcomm Technologies, Inc. WLED driver
 
 Required properties:
 - compatible: should be "qcom,pm8941-wled"
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 4e1d2ad..8c095e3 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -299,12 +299,12 @@ config BACKLIGHT_TOSA
 	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
 	  for its backlight
 
-config BACKLIGHT_PM8941_WLED
-	tristate "Qualcomm PM8941 WLED Driver"
+config BACKLIGHT_QCOM_WLED
+	tristate "Qualcomm PMIC WLED Driver"
 	select REGMAP
 	help
-	  If you have the Qualcomm PM8941, say Y to enable a driver for the
-	  WLED block.
+	  If you have the Qualcomm PMIC, say Y to enable a driver for the
+	  WLED block. Currently it supports PM8941 and PMI8998.
 
 config BACKLIGHT_SAHARA
 	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 5e28f01..6fd76ef 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -49,8 +49,8 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_OT200)		+= ot200_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
-obj-$(CONFIG_BACKLIGHT_PM8941_WLED)	+= pm8941-wled.o
 obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o
+obj-$(CONFIG_BACKLIGHT_QCOM_WLED)	+= qcom-wled.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)		+= kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_SKY81452)	+= sky81452-backlight.o
 obj-$(CONFIG_BACKLIGHT_TOSA)		+= tosa_bl.o
diff --git a/drivers/video/backlight/pm8941-wled.c b/drivers/video/backlight/qcom-wled.c
similarity index 100%
rename from drivers/video/backlight/pm8941-wled.c
rename to drivers/video/backlight/qcom-wled.c
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[Jingoo Han]

On Thursday, May 3, 2018 6:12 AM, Kiran Gunda wrote:

If you really want someone to review your patch, please add more detailed
explanations.

1. Please add 0th patch.
2. Please add what the difference is between V1 and V2 patches.

If you cannot understand what I am saying, just ask another person who have
an experience to send patches to Linux mailing-list.

Best regards,
Jingoo Han

> 
> pm8941-wled.c driver is supporting the WLED peripheral
> on pm8941. Rename it to qcom-wled.c so that it can support
> WLED on multiple PMICs.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 +-
>  drivers/video/backlight/Kconfig                                   | 8
++++----
>  drivers/video/backlight/Makefile                                  | 2 +-
>  drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0
>  4 files changed, 6 insertions(+), 6 deletions(-)
>  rename Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt
> => qcom-wled.txt} (95%)
>  rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)
> 
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pm8941-
> wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> similarity index 95%
> rename from Documentation/devicetree/bindings/leds/backlight/pm8941-
> wled.txt
> rename to Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> index e5b294d..fb39e32 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> @@ -1,4 +1,4 @@
> -Binding for Qualcomm PM8941 WLED driver
> +Binding for Qualcomm Technologies, Inc. WLED driver
> 
>  Required properties:
>  - compatible: should be "qcom,pm8941-wled"
> diff --git a/drivers/video/backlight/Kconfig
> b/drivers/video/backlight/Kconfig
> index 4e1d2ad..8c095e3 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -299,12 +299,12 @@ config BACKLIGHT_TOSA
>  	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
>  	  for its backlight
> 
> -config BACKLIGHT_PM8941_WLED
> -	tristate "Qualcomm PM8941 WLED Driver"
> +config BACKLIGHT_QCOM_WLED
> +	tristate "Qualcomm PMIC WLED Driver"
>  	select REGMAP
>  	help
> -	  If you have the Qualcomm PM8941, say Y to enable a driver for the
> -	  WLED block.
> +	  If you have the Qualcomm PMIC, say Y to enable a driver for the
> +	  WLED block. Currently it supports PM8941 and PMI8998.
> 
>  config BACKLIGHT_SAHARA
>  	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
> diff --git a/drivers/video/backlight/Makefile
> b/drivers/video/backlight/Makefile
> index 5e28f01..6fd76ef 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -49,8 +49,8 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)		+=
omap1_bl.o
>  obj-$(CONFIG_BACKLIGHT_OT200)		+= ot200_bl.o
>  obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
>  obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
> -obj-$(CONFIG_BACKLIGHT_PM8941_WLED)	+= pm8941-wled.o
>  obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o
> +obj-$(CONFIG_BACKLIGHT_QCOM_WLED)	+= qcom-wled.o
>  obj-$(CONFIG_BACKLIGHT_SAHARA)		+= kb3886_bl.o
>  obj-$(CONFIG_BACKLIGHT_SKY81452)	+= sky81452-backlight.o
>  obj-$(CONFIG_BACKLIGHT_TOSA)		+= tosa_bl.o
> diff --git a/drivers/video/backlight/pm8941-wled.c
> b/drivers/video/backlight/qcom-wled.c
> similarity index 100%
> rename from drivers/video/backlight/pm8941-wled.c
> rename to drivers/video/backlight/qcom-wled.c
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[kgunda]

Hi Jingoo Han,
Thanks for the response.

Thanks,
Kiran
On 2018-05-04 21:25, Jingoo Han wrote:
> On Thursday, May 3, 2018 6:12 AM, Kiran Gunda wrote:
> 
> If you really want someone to review your patch, please add more 
> detailed
> explanations.
> 
> 1. Please add 0th patch.
I have already added the 0th patch (cover letter). Following is the 
subject for the same.
forwarding the same to you.
[PATCH V2 0/5] backlight: qcom-wled: Support for QCOM wled driver

> 2. Please add what the difference is between V1 and V2 patches.
> 
Already added the difference between V1 and V2 in the cover letter (0th 
patch).
Please let me know if you are looking for any other info. Following is 
the difference
added between v1 and v2.
>>> 
changes from v1:
     Fixed the commit message for
     backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

> If you cannot understand what I am saying, just ask another person who 
> have
> an experience to send patches to Linux mailing-list.
> 
> Best regards,
> Jingoo Han
> 
>> 
>> pm8941-wled.c driver is supporting the WLED peripheral
>> on pm8941. Rename it to qcom-wled.c so that it can support
>> WLED on multiple PMICs.
>> 
>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> ---
>>  .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 
>> +-
>>  drivers/video/backlight/Kconfig                                   | 8
> ++++----
>>  drivers/video/backlight/Makefile                                  | 2 
>> +-
>>  drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0
>>  4 files changed, 6 insertions(+), 6 deletions(-)
>>  rename 
>> Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt
>> => qcom-wled.txt} (95%)
>>  rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)
>> 
>> diff --git a/Documentation/devicetree/bindings/leds/backlight/pm8941-
>> wled.txt 
>> b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
>> similarity index 95%
>> rename from Documentation/devicetree/bindings/leds/backlight/pm8941-
>> wled.txt
>> rename to 
>> Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
>> index e5b294d..fb39e32 100644
>> --- a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
>> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
>> @@ -1,4 +1,4 @@
>> -Binding for Qualcomm PM8941 WLED driver
>> +Binding for Qualcomm Technologies, Inc. WLED driver
>> 
>>  Required properties:
>>  - compatible: should be "qcom,pm8941-wled"
>> diff --git a/drivers/video/backlight/Kconfig
>> b/drivers/video/backlight/Kconfig
>> index 4e1d2ad..8c095e3 100644
>> --- a/drivers/video/backlight/Kconfig
>> +++ b/drivers/video/backlight/Kconfig
>> @@ -299,12 +299,12 @@ config BACKLIGHT_TOSA
>>  	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
>>  	  for its backlight
>> 
>> -config BACKLIGHT_PM8941_WLED
>> -	tristate "Qualcomm PM8941 WLED Driver"
>> +config BACKLIGHT_QCOM_WLED
>> +	tristate "Qualcomm PMIC WLED Driver"
>>  	select REGMAP
>>  	help
>> -	  If you have the Qualcomm PM8941, say Y to enable a driver for the
>> -	  WLED block.
>> +	  If you have the Qualcomm PMIC, say Y to enable a driver for the
>> +	  WLED block. Currently it supports PM8941 and PMI8998.
>> 
>>  config BACKLIGHT_SAHARA
>>  	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
>> diff --git a/drivers/video/backlight/Makefile
>> b/drivers/video/backlight/Makefile
>> index 5e28f01..6fd76ef 100644
>> --- a/drivers/video/backlight/Makefile
>> +++ b/drivers/video/backlight/Makefile
>> @@ -49,8 +49,8 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)		+=
> omap1_bl.o
>>  obj-$(CONFIG_BACKLIGHT_OT200)		+= ot200_bl.o
>>  obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
>>  obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
>> -obj-$(CONFIG_BACKLIGHT_PM8941_WLED)	+= pm8941-wled.o
>>  obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o
>> +obj-$(CONFIG_BACKLIGHT_QCOM_WLED)	+= qcom-wled.o
>>  obj-$(CONFIG_BACKLIGHT_SAHARA)		+= kb3886_bl.o
>>  obj-$(CONFIG_BACKLIGHT_SKY81452)	+= sky81452-backlight.o
>>  obj-$(CONFIG_BACKLIGHT_TOSA)		+= tosa_bl.o
>> diff --git a/drivers/video/backlight/pm8941-wled.c
>> b/drivers/video/backlight/qcom-wled.c
>> similarity index 100%
>> rename from drivers/video/backlight/pm8941-wled.c
>> rename to drivers/video/backlight/qcom-wled.c
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>>  a Linux Foundation Collaborative Project

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[Daniel Thompson]

On Mon, May 07, 2018 at 11:26:59AM +0530, kgunda@codeaurora.org wrote:
> Hi Jingoo Han,
> Thanks for the response.
> 
> Thanks,
> Kiran
> On 2018-05-04 21:25, Jingoo Han wrote:
> > On Thursday, May 3, 2018 6:12 AM, Kiran Gunda wrote:
> > 
> > If you really want someone to review your patch, please add more
> > detailed
> > explanations.
> > 
> > 1. Please add 0th patch.
> I have already added the 0th patch (cover letter). Following is the subject
> for the same.
> forwarding the same to you.
> [PATCH V2 0/5] backlight: qcom-wled: Support for QCOM wled driver

Perhaps you should interpret Jingoo's comment as a request to improve
the To: and Cc: list on the 0th patch the next time you circulate it.

Many maintainers configure their mailers to give patches where they are
in the To: or Cc: list special treatment so it confusing when a series
arrives with a spartan set of recipients for the 0th patch (and doubly
confusing when every patch in the set targets the same driver).


Daniel.

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[kgunda]

On 2018-05-08 14:06, Daniel Thompson wrote:
> On Mon, May 07, 2018 at 11:26:59AM +0530, kgunda@codeaurora.org wrote:
>> Hi Jingoo Han,
>> Thanks for the response.
>> 
>> Thanks,
>> Kiran
>> On 2018-05-04 21:25, Jingoo Han wrote:
>> > On Thursday, May 3, 2018 6:12 AM, Kiran Gunda wrote:
>> >
>> > If you really want someone to review your patch, please add more
>> > detailed
>> > explanations.
>> >
>> > 1. Please add 0th patch.
>> I have already added the 0th patch (cover letter). Following is the 
>> subject
>> for the same.
>> forwarding the same to you.
>> [PATCH V2 0/5] backlight: qcom-wled: Support for QCOM wled driver
> 
> Perhaps you should interpret Jingoo's comment as a request to improve
> the To: and Cc: list on the 0th patch the next time you circulate it.
> 
> Many maintainers configure their mailers to give patches where they are
> in the To: or Cc: list special treatment so it confusing when a series
> arrives with a spartan set of recipients for the 0th patch (and doubly
> confusing when every patch in the set targets the same driver).
> 
> 
> Daniel.
Ok. Got it. Not sure how the To: Cc: list on the 0th patch got shrink, 
while I was
using the To: Cc: list same for all the patches. Anyways, will double 
check of it while
circulating the next series.

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[Rob Herring]

On Thu, May 03, 2018 at 03:42:28PM +0530, Kiran Gunda wrote:
> pm8941-wled.c driver is supporting the WLED peripheral
> on pm8941. Rename it to qcom-wled.c so that it can support
> WLED on multiple PMICs.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 +-

Please split DT bindings from driver patches.

>  drivers/video/backlight/Kconfig                                   | 8 ++++----
>  drivers/video/backlight/Makefile                                  | 2 +-
>  drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0
>  4 files changed, 6 insertions(+), 6 deletions(-)
>  rename Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt} (95%)
>  rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[kgunda]

On 2018-05-07 22:10, Rob Herring wrote:
> On Thu, May 03, 2018 at 03:42:28PM +0530, Kiran Gunda wrote:
>> pm8941-wled.c driver is supporting the WLED peripheral
>> on pm8941. Rename it to qcom-wled.c so that it can support
>> WLED on multiple PMICs.
>> 
>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> ---
>>  .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 
>> +-
> 
> Please split DT bindings from driver patches.
> 
Sure. Will do that in the next series.
>>  drivers/video/backlight/Kconfig                                   | 8 
>> ++++----
>>  drivers/video/backlight/Makefile                                  | 2 
>> +-
>>  drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0
>>  4 files changed, 6 insertions(+), 6 deletions(-)
>>  rename 
>> Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt => 
>> qcom-wled.txt} (95%)
>>  rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)
> --
> To unsubscribe from this list: send the line "unsubscribe 
> linux-arm-msm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V2 1/5] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c

[Daniel Thompson]

On Thu, May 03, 2018 at 03:42:28PM +0530, Kiran Gunda wrote:
> pm8941-wled.c driver is supporting the WLED peripheral
> on pm8941. Rename it to qcom-wled.c so that it can support
> WLED on multiple PMICs.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  .../bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt}    | 2 +-
>  drivers/video/backlight/Kconfig                                   | 8 ++++----
>  drivers/video/backlight/Makefile                                  | 2 +-
>  drivers/video/backlight/{pm8941-wled.c => qcom-wled.c}            | 0

For me this hovers extremely close to being a gratuitous renaming
especially with no effort to bridge the gap between old and new names.

On the other hand, no current defconfig enables BACKLIGHT_PM8941_WLED,
it is configured by DT (so modules.conf tricks are unlikely) and any distros
that already have it enables are likely to be aggressive in enabling
drivers (so will probably turn on BACKLIGHT_QCOM_WLED as soon as it
appears).

On that basis I can live with this... but will also listen for any
complaints!


Daniel.

>  4 files changed, 6 insertions(+), 6 deletions(-)
>  rename Documentation/devicetree/bindings/leds/backlight/{pm8941-wled.txt => qcom-wled.txt} (95%)
>  rename drivers/video/backlight/{pm8941-wled.c => qcom-wled.c} (100%)
> 
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> similarity index 95%
> rename from Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
> rename to Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> index e5b294d..fb39e32 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/pm8941-wled.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> @@ -1,4 +1,4 @@
> -Binding for Qualcomm PM8941 WLED driver
> +Binding for Qualcomm Technologies, Inc. WLED driver
>  
>  Required properties:
>  - compatible: should be "qcom,pm8941-wled"
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 4e1d2ad..8c095e3 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -299,12 +299,12 @@ config BACKLIGHT_TOSA
>  	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
>  	  for its backlight
>  
> -config BACKLIGHT_PM8941_WLED
> -	tristate "Qualcomm PM8941 WLED Driver"
> +config BACKLIGHT_QCOM_WLED
> +	tristate "Qualcomm PMIC WLED Driver"
>  	select REGMAP
>  	help
> -	  If you have the Qualcomm PM8941, say Y to enable a driver for the
> -	  WLED block.
> +	  If you have the Qualcomm PMIC, say Y to enable a driver for the
> +	  WLED block. Currently it supports PM8941 and PMI8998.
>  
>  config BACKLIGHT_SAHARA
>  	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
> diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> index 5e28f01..6fd76ef 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -49,8 +49,8 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
>  obj-$(CONFIG_BACKLIGHT_OT200)		+= ot200_bl.o
>  obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
>  obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
> -obj-$(CONFIG_BACKLIGHT_PM8941_WLED)	+= pm8941-wled.o
>  obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o
> +obj-$(CONFIG_BACKLIGHT_QCOM_WLED)	+= qcom-wled.o
>  obj-$(CONFIG_BACKLIGHT_SAHARA)		+= kb3886_bl.o
>  obj-$(CONFIG_BACKLIGHT_SKY81452)	+= sky81452-backlight.o
>  obj-$(CONFIG_BACKLIGHT_TOSA)		+= tosa_bl.o
> diff --git a/drivers/video/backlight/pm8941-wled.c b/drivers/video/backlight/qcom-wled.c
> similarity index 100%
> rename from drivers/video/backlight/pm8941-wled.c
> rename to drivers/video/backlight/qcom-wled.c
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project
> 

[PATCH V2 2/5] backlight: qcom-wled: Add support for WLED4 peripheral

[Kiran Gunda]

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.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 .../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".
+
+- 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.
+
+- 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
+		      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.
+
+- qcom,current-boost-limit
+	Usage:        optional
+	Value type:   <u32>
+	Definition:   mA; boost current limit.
+		      For pm8941: one of: 105, 385, 525, 805, 980, 1260, 1400,
+				 1680. Default: 805 mA
+		      For pmi8998: one of: 105, 280, 450, 620, 970, 1150, 1300,
+				  1500. Default: 970 mA
+
+- qcom,switching-freq
+	Usage:        optional
+	Value type:   <u32>
+	Definition:   kHz; switching frequency; one of: 600, 640, 685, 738,
+		      800, 872, 960, 1066, 1200, 1371, 1600, 1920, 2400, 3200,
+		      4800, 9600.
+		      Default: for pm8941: 1600 kHz
+			      for pmi8998: 800 kHz
+
+- qcom,ovp
+	Usage:        optional
+	Value type:   <u32>
+	Definition:   mV; Over-voltage protection limit;
+		      For pm8941:  one of 27000, 29000, 32000, 35000
+				  Default: 29000 mV
+		      For pmi8998: one of 18100, 19600, 29600, 31100
+				  Default: 29600 mV
+
+- qcom,num-strings
+	Usage:        optional
+	Value type:   <u32>
+	Definition:   #; number of led strings attached;
+		      for pm8941: value 3.
+		      for pmi8998: value 4.
+
+- qcom,enabled-strings
+	Usage:        optional
+	Value tyoe:   <u32>
+	Definition:   Bit mask of the WLED strings. Bit 0 to 3 indicates strings
+		      0 to 3 respectively. Each string of leds are operated
+		      individually. Specify the strings using the bit mask. Any
+		      combination of led strings can be used.
+		      for pm8941: Default value is 7 (b111).
+		      for pmi8998: Default value is 15 (b1111).
+
+- qcom,cs-out
+	Usage:        optional
+	Value type:   <bool>
+	Definition:   enable current sink output.
+		      This property is supported only for PM8941.
+
+- qcom,cabc
+	Usage:        optional
+	Value type:   <bool>
+	Definition:   enable content adaptive backlight control.
+
+- qcom,ext-gen
+	Usage:        optional
+	Value type:   <bool>
+	Definition:   use externally generated modulator signal to dim.
+		      This property is supported only for PM8941.
+
+- qcom,external-pfet
+	Usage:        optional
+	Value type:   <bool>
+	Definition:   Specify if external PFET control for short circuit
+		      protection is used. This property is supported only
+		      for PMI8998.
+
+- qcom,auto-string-detection
+	Usage:        optional
+	Value type:   <bool>
+	Definition:   Enables auto-detection of the WLED string configuration.
+		      This feature is not supported for PM8941.
 
 Example:
 
@@ -34,9 +133,26 @@ pm8941-wled@d800 {
 	label = "backlight";
 
 	qcom,cs-out;
-	qcom,current-limit = <20>;
+	qcom,current-limit = <20000>;
+	qcom,current-boost-limit = <805>;
+	qcom,switching-freq = <1600>;
+	qcom,ovp = <29000>;
+	qcom,num-strings = <3>;
+	qcom,enabled-strings = <7>;
+};
+
+pmi8998-wled@d800 {
+	compatible = "qcom,pmi8998-wled";
+	reg = <0xd800 0xd900>;
+	label = "backlight";
+
+	interrupts = <3 0xd8 2 IRQ_TYPE_EDGE_RISING>,
+		     <3 0xd8 1 IRQ_TYPE_EDGE_RISING>;
+	interrupt-names = "short", "ovp";
+	qcom,current-limit = <25000>;
 	qcom,current-boost-limit = <805>;
 	qcom,switching-freq = <1600>;
-	qcom,ovp = <29>;
-	qcom,num-strings = <2>;
+	qcom,ovp = <29600>;
+	qcom,num-strings = <4>;
+	qcom,enabled-strings = <15>;
 };
diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 0b6d219..be8b8d3 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -15,253 +15,529 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_address.h>
 #include <linux/regmap.h>
 
 /* From DT binding */
-#define PM8941_WLED_DEFAULT_BRIGHTNESS		2048
+#define WLED_DEFAULT_BRIGHTNESS				2048
 
-#define PM8941_WLED_REG_VAL_BASE		0x40
-#define  PM8941_WLED_REG_VAL_MAX		0xFFF
+#define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
 
-#define PM8941_WLED_REG_MOD_EN			0x46
-#define  PM8941_WLED_REG_MOD_EN_BIT		BIT(7)
-#define  PM8941_WLED_REG_MOD_EN_MASK		BIT(7)
+/* Control registers */
+#define WLED3_CTRL_REG_MOD_EN				0x46
+#define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
 
-#define PM8941_WLED_REG_SYNC			0x47
-#define  PM8941_WLED_REG_SYNC_MASK		0x07
-#define  PM8941_WLED_REG_SYNC_LED1		BIT(0)
-#define  PM8941_WLED_REG_SYNC_LED2		BIT(1)
-#define  PM8941_WLED_REG_SYNC_LED3		BIT(2)
-#define  PM8941_WLED_REG_SYNC_ALL		0x07
-#define  PM8941_WLED_REG_SYNC_CLEAR		0x00
+#define WLED3_CTRL_REG_FREQ				0x4c
+#define  WLED3_CTRL_REG_FREQ_MASK			GENMASK(3, 0)
 
-#define PM8941_WLED_REG_FREQ			0x4c
-#define  PM8941_WLED_REG_FREQ_MASK		0x0f
+#define WLED3_CTRL_REG_OVP				0x4d
+#define  WLED3_CTRL_REG_OVP_MASK			GENMASK(1, 0)
 
-#define PM8941_WLED_REG_OVP			0x4d
-#define  PM8941_WLED_REG_OVP_MASK		0x03
+#define WLED3_CTRL_REG_ILIMIT				0x4e
+#define  WLED3_CTRL_REG_ILIMIT_MASK			GENMASK(2, 0)
 
-#define PM8941_WLED_REG_BOOST			0x4e
-#define  PM8941_WLED_REG_BOOST_MASK		0x07
+/* sink registers */
+#define WLED3_SINK_REG_SYNC				0x47
+#define  WLED3_SINK_REG_SYNC_MASK			GENMASK(2, 0)
+#define  WLED4_SINK_REG_SYNC_MASK			GENMASK(3, 0)
+#define  WLED3_SINK_REG_SYNC_LED1			BIT(0)
+#define  WLED3_SINK_REG_SYNC_LED2			BIT(1)
+#define  WLED3_SINK_REG_SYNC_LED3			BIT(2)
+#define  WLED4_SINK_REG_SYNC_LED4			BIT(3)
+#define  WLED3_SINK_REG_SYNC_ALL			0x07
+#define  WLED4_SINK_REG_SYNC_ALL			0x0f
+#define  WLED3_SINK_REG_SYNC_CLEAR			0x00
 
-#define PM8941_WLED_REG_SINK			0x4f
-#define  PM8941_WLED_REG_SINK_MASK		0xe0
-#define  PM8941_WLED_REG_SINK_SHFT		0x05
+#define WLED3_SINK_REG_CURR_SINK			0x4f
+#define  WLED3_SINK_REG_CURR_SINK_MASK			GENMASK(7, 5)
+#define  WLED3_SINK_REG_CURR_SINK_SHFT			5
 
-/* Per-'string' registers below */
-#define PM8941_WLED_REG_STR_OFFSET		0x10
+/* WLED3 Per-'string' registers below */
+#define WLED3_SINK_REG_BRIGHT(n)			(0x40 + n)
 
-#define PM8941_WLED_REG_STR_MOD_EN_BASE		0x60
-#define  PM8941_WLED_REG_STR_MOD_MASK		BIT(7)
-#define  PM8941_WLED_REG_STR_MOD_EN		BIT(7)
+#define WLED3_SINK_REG_STR_MOD_EN(n)			(0x60 + (n * 0x10))
+#define  WLED3_SINK_REG_STR_MOD_MASK			BIT(7)
 
-#define PM8941_WLED_REG_STR_SCALE_BASE		0x62
-#define  PM8941_WLED_REG_STR_SCALE_MASK		0x1f
+#define WLED3_SINK_REG_STR_FULL_SCALE_CURR(n)		(0x62 + (n * 0x10))
+#define  WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK	GENMASK(4, 0)
 
-#define PM8941_WLED_REG_STR_MOD_SRC_BASE	0x63
-#define  PM8941_WLED_REG_STR_MOD_SRC_MASK	0x01
-#define  PM8941_WLED_REG_STR_MOD_SRC_INT	0x00
-#define  PM8941_WLED_REG_STR_MOD_SRC_EXT	0x01
+#define WLED3_SINK_REG_STR_MOD_SRC(n)			(0x63 + (n * 0x10))
+#define  WLED3_SINK_REG_STR_MOD_SRC_MASK		BIT(0)
+#define  WLED3_SINK_REG_STR_MOD_SRC_INT			0x00
+#define  WLED3_SINK_REG_STR_MOD_SRC_EXT			0x01
 
-#define PM8941_WLED_REG_STR_CABC_BASE		0x66
-#define  PM8941_WLED_REG_STR_CABC_MASK		BIT(7)
-#define  PM8941_WLED_REG_STR_CABC_EN		BIT(7)
+#define WLED3_SINK_REG_STR_CABC(n)			(0x66 + (n * 0x10))
+#define  WLED3_SINK_REG_STR_CABC_MASK			BIT(7)
 
-struct pm8941_wled_config {
-	u32 i_boost_limit;
+/* WLED4 sink specific registers */
+#define WLED4_SINK_REG_CURR_SINK			0x46
+#define  WLED4_SINK_REG_CURR_SINK_MASK			GENMASK(7, 4)
+#define  WLED4_SINK_REG_CURR_SINK_SHFT			4
+
+/* WLED4 Per-'string' registers below */
+#define WLED4_SINK_REG_STR_MOD_EN(n)			(0x50 + (n * 0x10))
+#define  WLED4_SINK_REG_STR_MOD_MASK			BIT(7)
+
+#define WLED4_SINK_REG_STR_FULL_SCALE_CURR(n)		(0x52 + (n * 0x10))
+#define  WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK	GENMASK(3, 0)
+
+#define WLED4_SINK_REG_STR_MOD_SRC(n)			(0x53 + (n * 0x10))
+#define  WLED4_SINK_REG_STR_MOD_SRC_MASK		BIT(0)
+#define  WLED4_SINK_REG_STR_MOD_SRC_INT			0x00
+#define  WLED4_SINK_REG_STR_MOD_SRC_EXT			0x01
+
+#define WLED4_SINK_REG_STR_CABC(n)			(0x56 + (n * 0x10))
+#define  WLED4_SINK_REG_STR_CABC_MASK			BIT(7)
+
+#define WLED4_SINK_REG_BRIGHT(n)			(0x57 + (n * 0x10))
+
+enum wled_version {
+	WLED_PM8941 = 3,
+	WLED_PMI8998,
+	WLED_PM660L,
+};
+
+static const int version_table[] = {
+	[0] = WLED_PM8941,
+	[1] = WLED_PMI8998,
+	[2] = WLED_PM660L,
+};
+
+struct wled_var_cfg {
+	const u32 *values;
+	u32 (*fn)(u32);
+	int size;
+};
+
+struct wled_u32_opts {
+	const char *name;
+	u32 *val_ptr;
+	const struct wled_var_cfg *cfg;
+};
+
+struct wled_bool_opts {
+	const char *name;
+	bool *val_ptr;
+};
+
+struct wled_config {
+	u32 boost_i_limit;
 	u32 ovp;
 	u32 switch_freq;
 	u32 num_strings;
-	u32 i_limit;
+	u32 string_i_limit;
+	u32 enabled_strings;
 	bool cs_out_en;
 	bool ext_gen;
-	bool cabc_en;
+	bool cabc;
 };
 
-struct pm8941_wled {
+struct wled {
 	const char *name;
+	struct device *dev;
 	struct regmap *regmap;
-	u16 addr;
-
-	struct pm8941_wled_config cfg;
+	u16 ctrl_addr;
+	u16 sink_addr;
+	u32 brightness;
+	u32 max_brightness;
+	const int *version;
+
+	struct wled_config cfg;
+	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
+	int (*wled_sync_toggle)(struct wled *wled);
 };
 
-static int pm8941_wled_update_status(struct backlight_device *bl)
+static int wled3_set_brightness(struct wled *wled, u16 brightness)
 {
-	struct pm8941_wled *wled = bl_get_data(bl);
-	u16 val = bl->props.brightness;
-	u8 ctrl = 0;
-	int rc;
-	int i;
+	int rc, i;
+	u8 v[2];
 
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & BL_CORE_FBBLANK)
-		val = 0;
+	v[0] = brightness & 0xff;
+	v[1] = (brightness >> 8) & 0xf;
 
-	if (val != 0)
-		ctrl = PM8941_WLED_REG_MOD_EN_BIT;
+	for (i = 0;  i < wled->cfg.num_strings; ++i) {
+		rc = regmap_bulk_write(wled->regmap, wled->ctrl_addr +
+				       WLED3_SINK_REG_BRIGHT(i), v, 2);
+		if (rc < 0)
+			return rc;
+	}
 
-	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_MOD_EN,
-			PM8941_WLED_REG_MOD_EN_MASK, ctrl);
-	if (rc)
-		return rc;
+	return 0;
+}
 
-	for (i = 0; i < wled->cfg.num_strings; ++i) {
-		u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
+static int wled4_set_brightness(struct wled *wled, u16 brightness)
+{
+	int rc, i;
+	u16 low_limit = wled->max_brightness * 4 / 1000;
+	u8 v[2];
 
-		rc = regmap_bulk_write(wled->regmap,
-				wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i,
-				v, 2);
-		if (rc)
+	/* WLED4's lower limit of operation is 0.4% */
+	if (brightness > 0 && brightness < low_limit)
+		brightness = low_limit;
+
+	v[0] = brightness & 0xff;
+	v[1] = (brightness >> 8) & 0xf;
+
+	for (i = 0;  i < wled->cfg.num_strings; ++i) {
+		rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
+				       WLED4_SINK_REG_BRIGHT(i), v, 2);
+		if (rc < 0)
 			return rc;
 	}
 
+	return 0;
+}
+
+static int wled_module_enable(struct wled *wled, int val)
+{
+	int rc;
+
+	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
+				WLED3_CTRL_REG_MOD_EN,
+				WLED3_CTRL_REG_MOD_EN_MASK,
+				WLED3_CTRL_REG_MOD_EN_MASK);
+	return rc;
+}
+
+static int wled3_sync_toggle(struct wled *wled)
+{
+	int rc;
+
 	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_SYNC,
-			PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL);
-	if (rc)
+				wled->ctrl_addr + WLED3_SINK_REG_SYNC,
+				WLED3_SINK_REG_SYNC_MASK,
+				WLED3_SINK_REG_SYNC_MASK);
+	if (rc < 0)
 		return rc;
 
 	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_SYNC,
-			PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR);
+				wled->ctrl_addr + WLED3_SINK_REG_SYNC,
+				WLED3_SINK_REG_SYNC_MASK,
+				WLED3_SINK_REG_SYNC_CLEAR);
+
 	return rc;
 }
 
-static int pm8941_wled_setup(struct pm8941_wled *wled)
+static int wled4_sync_toggle(struct wled *wled)
 {
 	int rc;
-	int i;
 
 	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_OVP,
-			PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp);
-	if (rc)
+				wled->sink_addr + WLED3_SINK_REG_SYNC,
+				WLED4_SINK_REG_SYNC_MASK,
+				WLED4_SINK_REG_SYNC_MASK);
+	if (rc < 0)
 		return rc;
 
 	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_BOOST,
-			PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit);
+				wled->sink_addr + WLED3_SINK_REG_SYNC,
+				WLED4_SINK_REG_SYNC_MASK,
+				WLED3_SINK_REG_SYNC_CLEAR);
+
+	return rc;
+}
+
+static int wled_update_status(struct backlight_device *bl)
+{
+	struct wled *wled = bl_get_data(bl);
+	u16 brightness = bl->props.brightness;
+	int rc = 0;
+
+	if (bl->props.power != FB_BLANK_UNBLANK ||
+	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
+	    bl->props.state & BL_CORE_FBBLANK)
+		brightness = 0;
+
+	if (brightness) {
+		rc = wled->wled_set_brightness(wled, brightness);
+		if (rc < 0) {
+			dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
+				rc);
+			return rc;
+		}
+
+		rc = wled->wled_sync_toggle(wled);
+		if (rc < 0) {
+			dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
+			return rc;
+		}
+	}
+
+	if (!!brightness != !!wled->brightness) {
+		rc = wled_module_enable(wled, !!brightness);
+		if (rc < 0) {
+			dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
+			return rc;
+		}
+	}
+
+	wled->brightness = brightness;
+
+	return rc;
+}
+
+static int wled3_setup(struct wled *wled)
+{
+	u16 addr;
+	u8 enabled_strings = wled->cfg.enabled_strings;
+	u8 sink_en = 0;
+	int rc, i;
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_OVP,
+				WLED3_CTRL_REG_OVP_MASK, wled->cfg.ovp);
 	if (rc)
 		return rc;
 
 	rc = regmap_update_bits(wled->regmap,
-			wled->addr + PM8941_WLED_REG_FREQ,
-			PM8941_WLED_REG_FREQ_MASK, wled->cfg.switch_freq);
+				wled->ctrl_addr + WLED3_CTRL_REG_ILIMIT,
+				WLED3_CTRL_REG_ILIMIT_MASK,
+				wled->cfg.boost_i_limit);
 	if (rc)
 		return rc;
 
-	if (wled->cfg.cs_out_en) {
-		u8 all = (BIT(wled->cfg.num_strings) - 1)
-				<< PM8941_WLED_REG_SINK_SHFT;
-
-		rc = regmap_update_bits(wled->regmap,
-				wled->addr + PM8941_WLED_REG_SINK,
-				PM8941_WLED_REG_SINK_MASK, all);
-		if (rc)
-			return rc;
-	}
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_FREQ,
+				WLED3_CTRL_REG_FREQ_MASK,
+				wled->cfg.switch_freq);
+	if (rc)
+		return rc;
 
 	for (i = 0; i < wled->cfg.num_strings; ++i) {
-		u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i;
+		if (!(enabled_strings & BIT(i)))
+			continue;
 
-		rc = regmap_update_bits(wled->regmap,
-				addr + PM8941_WLED_REG_STR_MOD_EN_BASE,
-				PM8941_WLED_REG_STR_MOD_MASK,
-				PM8941_WLED_REG_STR_MOD_EN);
+		addr = wled->ctrl_addr + WLED3_SINK_REG_STR_MOD_EN(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED3_SINK_REG_STR_MOD_MASK,
+					WLED3_SINK_REG_STR_MOD_MASK);
 		if (rc)
 			return rc;
 
 		if (wled->cfg.ext_gen) {
-			rc = regmap_update_bits(wled->regmap,
-					addr + PM8941_WLED_REG_STR_MOD_SRC_BASE,
-					PM8941_WLED_REG_STR_MOD_SRC_MASK,
-					PM8941_WLED_REG_STR_MOD_SRC_EXT);
+			addr = wled->ctrl_addr + WLED3_SINK_REG_STR_MOD_SRC(i);
+			rc = regmap_update_bits(wled->regmap, addr,
+						WLED3_SINK_REG_STR_MOD_SRC_MASK,
+						WLED3_SINK_REG_STR_MOD_SRC_EXT);
 			if (rc)
 				return rc;
 		}
 
-		rc = regmap_update_bits(wled->regmap,
-				addr + PM8941_WLED_REG_STR_SCALE_BASE,
-				PM8941_WLED_REG_STR_SCALE_MASK,
-				wled->cfg.i_limit);
+		addr = wled->ctrl_addr + WLED3_SINK_REG_STR_FULL_SCALE_CURR(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED3_SINK_REG_STR_FULL_SCALE_CURR_MASK,
+					wled->cfg.string_i_limit);
 		if (rc)
 			return rc;
 
-		rc = regmap_update_bits(wled->regmap,
-				addr + PM8941_WLED_REG_STR_CABC_BASE,
-				PM8941_WLED_REG_STR_CABC_MASK,
-				wled->cfg.cabc_en ?
-					PM8941_WLED_REG_STR_CABC_EN : 0);
+		addr = wled->ctrl_addr + WLED3_SINK_REG_STR_CABC(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED3_SINK_REG_STR_CABC_MASK,
+					wled->cfg.cabc ?
+					WLED3_SINK_REG_STR_CABC_MASK : 0);
 		if (rc)
 			return rc;
+
+		sink_en |= BIT(i + WLED3_SINK_REG_CURR_SINK_SHFT);
 	}
 
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_SINK_REG_CURR_SINK,
+				WLED3_SINK_REG_CURR_SINK_MASK, sink_en);
+	if (rc)
+		return rc;
+
 	return 0;
 }
 
-static const struct pm8941_wled_config pm8941_wled_config_defaults = {
-	.i_boost_limit = 3,
-	.i_limit = 20,
+static const struct wled_config wled3_config_defaults = {
+	.boost_i_limit = 3,
+	.string_i_limit = 20,
 	.ovp = 2,
+	.num_strings = 3,
 	.switch_freq = 5,
-	.num_strings = 0,
+	.enabled_strings = 7,
 	.cs_out_en = false,
 	.ext_gen = false,
-	.cabc_en = false,
+	.cabc = false,
 };
 
-struct pm8941_wled_var_cfg {
-	const u32 *values;
-	u32 (*fn)(u32);
-	int size;
+static int wled4_setup(struct wled *wled)
+{
+	int rc, temp, i;
+	u16 addr;
+	u8 sink_en = 0;
+	u8 enabled_strings = wled->cfg.enabled_strings;
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_OVP,
+				WLED3_CTRL_REG_OVP_MASK, wled->cfg.ovp);
+	if (rc < 0)
+		return rc;
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_ILIMIT,
+				WLED3_CTRL_REG_ILIMIT_MASK,
+				wled->cfg.boost_i_limit);
+	if (rc < 0)
+		return rc;
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_FREQ,
+				WLED3_CTRL_REG_FREQ_MASK,
+				wled->cfg.switch_freq);
+	if (rc < 0)
+		return rc;
+
+	/* Per sink/string configuration */
+	for (i = 0; i < wled->cfg.num_strings; i++) {
+		if (!(enabled_strings & BIT(i)))
+			continue;
+
+		addr = wled->sink_addr +
+				WLED4_SINK_REG_STR_MOD_EN(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED4_SINK_REG_STR_MOD_MASK,
+					WLED4_SINK_REG_STR_MOD_MASK);
+		if (rc < 0)
+			return rc;
+
+		addr = wled->sink_addr +
+				WLED4_SINK_REG_STR_FULL_SCALE_CURR(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK,
+					wled->cfg.string_i_limit);
+		if (rc < 0)
+			return rc;
+
+		addr = wled->sink_addr +
+				WLED4_SINK_REG_STR_CABC(i);
+		rc = regmap_update_bits(wled->regmap, addr,
+					WLED4_SINK_REG_STR_CABC_MASK,
+					wled->cfg.cabc ?
+					WLED4_SINK_REG_STR_CABC_MASK : 0);
+		if (rc < 0)
+			return rc;
+
+		temp = i + WLED4_SINK_REG_CURR_SINK_SHFT;
+		sink_en |= 1 << temp;
+	}
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
+				WLED4_SINK_REG_CURR_SINK_MASK, sink_en);
+	if (rc < 0)
+		return rc;
+
+	rc = wled->wled_sync_toggle(wled);
+	if (rc < 0) {
+		dev_err(wled->dev, "Failed to toggle sync reg rc:%d\n", rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+static const struct wled_config wled4_config_defaults = {
+	.boost_i_limit = 4,
+	.string_i_limit = 10,
+	.ovp = 1,
+	.num_strings = 4,
+	.switch_freq = 11,
+	.enabled_strings = 0xf,
+	.cabc = false,
 };
 
-static const u32 pm8941_wled_i_boost_limit_values[] = {
+static const u32 wled3_boost_i_limit_values[] = {
 	105, 385, 525, 805, 980, 1260, 1400, 1680,
 };
 
-static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = {
-	.values = pm8941_wled_i_boost_limit_values,
-	.size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values),
+static const struct wled_var_cfg wled3_boost_i_limit_cfg = {
+	.values = wled3_boost_i_limit_values,
+	.size = ARRAY_SIZE(wled3_boost_i_limit_values),
 };
 
-static const u32 pm8941_wled_ovp_values[] = {
-	35, 32, 29, 27,
+static const u32 wled4_boost_i_limit_values[] = {
+	105, 280, 450, 620, 970, 1150, 1300, 1500,
 };
 
-static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = {
-	.values = pm8941_wled_ovp_values,
-	.size = ARRAY_SIZE(pm8941_wled_ovp_values),
+static const struct wled_var_cfg wled4_boost_i_limit_cfg = {
+	.values = wled4_boost_i_limit_values,
+	.size = ARRAY_SIZE(wled4_boost_i_limit_values),
 };
 
-static u32 pm8941_wled_num_strings_values_fn(u32 idx)
+static const u32 wled3_ovp_values[] = {
+	35000, 32000, 29000, 27000,
+};
+
+static const struct wled_var_cfg wled3_ovp_cfg = {
+	.values = wled3_ovp_values,
+	.size = ARRAY_SIZE(wled3_ovp_values),
+};
+
+static const u32 wled4_ovp_values[] = {
+	31100, 29600, 19600, 18100,
+};
+
+static const struct wled_var_cfg wled4_ovp_cfg = {
+	.values = wled4_ovp_values,
+	.size = ARRAY_SIZE(wled4_ovp_values),
+};
+
+static u32 wled3_num_strings_values_fn(u32 idx)
 {
 	return idx + 1;
 }
 
-static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = {
-	.fn = pm8941_wled_num_strings_values_fn,
+static const struct wled_var_cfg wled3_num_strings_cfg = {
+	.fn = wled3_num_strings_values_fn,
 	.size = 3,
 };
 
-static u32 pm8941_wled_switch_freq_values_fn(u32 idx)
+static const struct wled_var_cfg wled4_num_strings_cfg = {
+	.fn = wled3_num_strings_values_fn,
+	.size = 4,
+};
+
+static u32 wled3_switch_freq_values_fn(u32 idx)
 {
 	return 19200 / (2 * (1 + idx));
 }
 
-static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = {
-	.fn = pm8941_wled_switch_freq_values_fn,
+static const struct wled_var_cfg wled3_switch_freq_cfg = {
+	.fn = wled3_switch_freq_values_fn,
 	.size = 16,
 };
 
-static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = {
-	.size = 26,
+static const u32 wled3_string_i_limit_values[] = {
+	0, 2500, 5000, 7500, 10000, 12500, 15000, 17500, 20000,
+	22500, 25000,
 };
 
-static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
+static const struct wled_var_cfg wled3_string_i_limit_cfg = {
+	.values = wled3_string_i_limit_values,
+	.size = ARRAY_SIZE(wled3_string_i_limit_values),
+};
+
+static const u32 wled4_string_i_limit_values[] = {
+	0, 2500, 5000, 7500, 10000, 12500, 15000, 17500, 20000,
+	22500, 25000, 27500, 30000,
+};
+
+static const struct wled_var_cfg wled4_string_i_limit_cfg = {
+	.values = wled4_string_i_limit_values,
+	.size = ARRAY_SIZE(wled4_string_i_limit_values),
+};
+
+static const struct wled_var_cfg wled3_string_cfg = {
+	.size = 8,
+};
+
+static const struct wled_var_cfg wled4_string_cfg = {
+	.size = 16,
+};
+
+static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
 {
 	if (idx >= cfg->size)
 		return UINT_MAX;
@@ -272,68 +548,124 @@ static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
 	return idx;
 }
 
-static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
+static int wled_configure(struct wled *wled)
 {
-	struct pm8941_wled_config *cfg = &wled->cfg;
-	u32 val;
-	int rc;
-	u32 c;
-	int i;
-	int j;
-
-	const struct {
-		const char *name;
-		u32 *val_ptr;
-		const struct pm8941_wled_var_cfg *cfg;
-	} u32_opts[] = {
+	struct wled_config *cfg = &wled->cfg;
+	struct device *dev = wled->dev;
+	const __be32 *prop_addr;
+	u32 size, val, c;
+	int rc, i, j;
+
+	const struct wled_u32_opts *u32_opts = NULL;
+	const struct wled_u32_opts wled3_opts[] = {
+		{
+			.name = "qcom,current-boost-limit",
+			.val_ptr = &cfg->boost_i_limit,
+			.cfg = &wled3_boost_i_limit_cfg,
+		},
+		{
+			.name = "qcom,current-limit",
+			.val_ptr = &cfg->string_i_limit,
+			.cfg = &wled3_string_i_limit_cfg,
+		},
+		{
+			.name = "qcom,ovp",
+			.val_ptr = &cfg->ovp,
+			.cfg = &wled3_ovp_cfg,
+		},
+		{
+			.name = "qcom,switching-freq",
+			.val_ptr = &cfg->switch_freq,
+			.cfg = &wled3_switch_freq_cfg,
+		},
+		{
+			.name = "qcom,num-strings",
+			.val_ptr = &cfg->num_strings,
+			.cfg = &wled3_num_strings_cfg,
+		},
+		{
+			.name = "qcom,enabled-strings",
+			.val_ptr = &cfg->enabled_strings,
+			.cfg = &wled3_string_cfg,
+		},
+	};
+
+	const struct wled_u32_opts wled4_opts[] = {
 		{
-			"qcom,current-boost-limit",
-			&cfg->i_boost_limit,
-			.cfg = &pm8941_wled_i_boost_limit_cfg,
+			.name = "qcom,current-boost-limit",
+			.val_ptr = &cfg->boost_i_limit,
+			.cfg = &wled4_boost_i_limit_cfg,
 		},
 		{
-			"qcom,current-limit",
-			&cfg->i_limit,
-			.cfg = &pm8941_wled_i_limit_cfg,
+			.name = "qcom,current-limit",
+			.val_ptr = &cfg->string_i_limit,
+			.cfg = &wled4_string_i_limit_cfg,
 		},
 		{
-			"qcom,ovp",
-			&cfg->ovp,
-			.cfg = &pm8941_wled_ovp_cfg,
+			.name = "qcom,ovp",
+			.val_ptr = &cfg->ovp,
+			.cfg = &wled4_ovp_cfg,
 		},
 		{
-			"qcom,switching-freq",
-			&cfg->switch_freq,
-			.cfg = &pm8941_wled_switch_freq_cfg,
+			.name = "qcom,switching-freq",
+			.val_ptr = &cfg->switch_freq,
+			.cfg = &wled3_switch_freq_cfg,
 		},
 		{
-			"qcom,num-strings",
-			&cfg->num_strings,
-			.cfg = &pm8941_wled_num_strings_cfg,
+			.name = "qcom,num-strings",
+			.val_ptr = &cfg->num_strings,
+			.cfg = &wled4_num_strings_cfg,
 		},
+		{
+			.name = "qcom,enabled-strings",
+			.val_ptr = &cfg->enabled_strings,
+			.cfg = &wled4_string_cfg,
+		},
+
 	};
-	const struct {
-		const char *name;
-		bool *val_ptr;
-	} bool_opts[] = {
+
+	const struct wled_bool_opts bool_opts[] = {
 		{ "qcom,cs-out", &cfg->cs_out_en, },
 		{ "qcom,ext-gen", &cfg->ext_gen, },
-		{ "qcom,cabc", &cfg->cabc_en, },
+		{ "qcom,cabc", &cfg->cabc, },
 	};
 
-	rc = of_property_read_u32(dev->of_node, "reg", &val);
-	if (rc || val > 0xffff) {
-		dev_err(dev, "invalid IO resources\n");
-		return rc ? rc : -EINVAL;
+	prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
+	if (!prop_addr) {
+		dev_err(wled->dev, "invalid IO resources\n");
+		return -EINVAL;
+	}
+	wled->ctrl_addr = be32_to_cpu(*prop_addr);
+
+	if (*wled->version != WLED_PM8941) {
+		prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
+		if (!prop_addr) {
+			dev_err(wled->dev, "invalid IO resources\n");
+			return -EINVAL;
+		}
+		wled->sink_addr = be32_to_cpu(*prop_addr);
 	}
-	wled->addr = val;
 
 	rc = of_property_read_string(dev->of_node, "label", &wled->name);
 	if (rc)
 		wled->name = dev->of_node->name;
 
-	*cfg = pm8941_wled_config_defaults;
-	for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
+	if (*wled->version == WLED_PM8941) {
+		u32_opts = wled3_opts;
+		size = ARRAY_SIZE(wled3_opts);
+		*cfg = wled3_config_defaults;
+		wled->wled_set_brightness = wled3_set_brightness;
+		wled->wled_sync_toggle = wled3_sync_toggle;
+	} else if (*wled->version == WLED_PMI8998 ||
+			*wled->version == WLED_PM660L) {
+		u32_opts = wled4_opts;
+		size = ARRAY_SIZE(wled4_opts);
+		*cfg = wled4_config_defaults;
+		wled->wled_set_brightness = wled4_set_brightness;
+		wled->wled_sync_toggle = wled4_sync_toggle;
+	}
+
+	for (i = 0; i < size; ++i) {
 		rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
 		if (rc == -EINVAL) {
 			continue;
@@ -344,12 +676,15 @@ static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
 
 		c = UINT_MAX;
 		for (j = 0; c != val; j++) {
-			c = pm8941_wled_values(u32_opts[i].cfg, j);
+			c = wled_values(u32_opts[i].cfg, j);
 			if (c == UINT_MAX) {
 				dev_err(dev, "invalid value for '%s'\n",
 					u32_opts[i].name);
 				return -EINVAL;
 			}
+
+			if (c == val)
+				break;
 		}
 
 		dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c);
@@ -366,15 +701,15 @@ static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
 	return 0;
 }
 
-static const struct backlight_ops pm8941_wled_ops = {
-	.update_status = pm8941_wled_update_status,
+static const struct backlight_ops wled_ops = {
+	.update_status = wled_update_status,
 };
 
-static int pm8941_wled_probe(struct platform_device *pdev)
+static int wled_probe(struct platform_device *pdev)
 {
 	struct backlight_properties props;
 	struct backlight_device *bl;
-	struct pm8941_wled *wled;
+	struct wled *wled;
 	struct regmap *regmap;
 	u32 val;
 	int rc;
@@ -390,43 +725,63 @@ static int pm8941_wled_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	wled->regmap = regmap;
+	wled->dev = &pdev->dev;
 
-	rc = pm8941_wled_configure(wled, &pdev->dev);
-	if (rc)
-		return rc;
+	wled->version = of_device_get_match_data(&pdev->dev);
+	if (!wled->version) {
+		dev_err(&pdev->dev, "Unknown device version\n");
+		return -ENODEV;
+	}
 
-	rc = pm8941_wled_setup(wled);
+	rc = wled_configure(wled);
 	if (rc)
 		return rc;
 
-	val = PM8941_WLED_DEFAULT_BRIGHTNESS;
+	if (*wled->version == WLED_PM8941) {
+		rc = wled3_setup(wled);
+		if (rc) {
+			dev_err(&pdev->dev, "wled3_setup failed\n");
+			return rc;
+		}
+	} else if (*wled->version == WLED_PMI8998 ||
+			*wled->version == WLED_PM660L) {
+		rc = wled4_setup(wled);
+		if (rc) {
+			dev_err(&pdev->dev, "wled4_setup failed\n");
+			return rc;
+		}
+	}
+
+	val = WLED_DEFAULT_BRIGHTNESS;
 	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
 
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_RAW;
 	props.brightness = val;
-	props.max_brightness = PM8941_WLED_REG_VAL_MAX;
+	props.max_brightness = WLED3_SINK_REG_BRIGHT_MAX;
 	bl = devm_backlight_device_register(&pdev->dev, wled->name,
 					    &pdev->dev, wled,
-					    &pm8941_wled_ops, &props);
+					    &wled_ops, &props);
 	return PTR_ERR_OR_ZERO(bl);
 };
 
-static const struct of_device_id pm8941_wled_match_table[] = {
-	{ .compatible = "qcom,pm8941-wled" },
+static const struct of_device_id wled_match_table[] = {
+	{ .compatible = "qcom,pm8941-wled", .data = &version_table[0] },
+	{ .compatible = "qcom,pmi8998-wled", .data = &version_table[1] },
+	{ .compatible = "qcom,pm660l-wled", .data = &version_table[2] },
 	{}
 };
-MODULE_DEVICE_TABLE(of, pm8941_wled_match_table);
+MODULE_DEVICE_TABLE(of, wled_match_table);
 
-static struct platform_driver pm8941_wled_driver = {
-	.probe = pm8941_wled_probe,
+static struct platform_driver wled_driver = {
+	.probe = wled_probe,
 	.driver	= {
-		.name = "pm8941-wled",
-		.of_match_table	= pm8941_wled_match_table,
+		.name = "qcom,wled",
+		.of_match_table	= wled_match_table,
 	},
 };
 
-module_platform_driver(pm8941_wled_driver);
+module_platform_driver(wled_driver);
 
-MODULE_DESCRIPTION("pm8941 wled driver");
+MODULE_DESCRIPTION("qcom wled driver");
 MODULE_LICENSE("GPL v2");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

Re: [PATCH V2 2/5] backlight: qcom-wled: Add support for WLED4 peripheral

[Rob Herring]

On Thu, May 03, 2018 at 03:42:29PM +0530, 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.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  .../bindings/leds/backlight/qcom-wled.txt          | 172 ++++-

Please split bindings to a separate patch.

This is also a whole lot of churn re-formatting. That is fine, but don't 
mix actual changes to the binding with re-formatting. You can do 2 
patches in this case: 

- move and reformat (as long as the move shows up as a move 
and not a remove and add) 
- additions for new chips

>  drivers/video/backlight/qcom-wled.c                | 749 +++++++++++++++------
>  2 files changed, 696 insertions(+), 225 deletions(-)

Re: [PATCH V2 2/5] backlight: qcom-wled: Add support for WLED4 peripheral

[kgunda]

On 2018-05-07 22:15, Rob Herring wrote:
> On Thu, May 03, 2018 at 03:42:29PM +0530, 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.
>> 
>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> ---
>>  .../bindings/leds/backlight/qcom-wled.txt          | 172 ++++-
> 
> Please split bindings to a separate patch.
> 
> This is also a whole lot of churn re-formatting. That is fine, but 
> don't
> mix actual changes to the binding with re-formatting. You can do 2
> patches in this case:
> 
> - move and reformat (as long as the move shows up as a move
> and not a remove and add)
> - additions for new chips
> 
Sure. I will do it in the next series.
>>  drivers/video/backlight/qcom-wled.c                | 749 
>> +++++++++++++++------
>>  2 files changed, 696 insertions(+), 225 deletions(-)

[PATCH V2 3/5] backlight: qcom-wled: Add support for short circuit handling

[Kiran Gunda]

Handle the short circuit interrupt and check if the short circuit
interrupt is valid. Re-enable the module to check if it goes
away. Disable the module altogether if the short circuit event
persists.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 drivers/video/backlight/qcom-wled.c | 134 ++++++++++++++++++++++++++++++++++--
 1 file changed, 130 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index be8b8d3..2cfba77 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -10,6 +10,9 @@
  * GNU General Public License for more details.
  */
 
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/ktime.h>
 #include <linux/kernel.h>
 #include <linux/backlight.h>
 #include <linux/module.h>
@@ -23,7 +26,9 @@
 
 #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
 
-/* Control registers */
+/* WLED3 Control registers */
+#define WLED3_CTRL_REG_FAULT_STATUS			0x08
+
 #define WLED3_CTRL_REG_MOD_EN				0x46
 #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
 
@@ -36,7 +41,17 @@
 #define WLED3_CTRL_REG_ILIMIT				0x4e
 #define  WLED3_CTRL_REG_ILIMIT_MASK			GENMASK(2, 0)
 
-/* sink registers */
+/* WLED4 control registers */
+#define WLED4_CTRL_REG_SHORT_PROTECT			0x5e
+#define  WLED4_CTRL_REG_SHORT_EN_MASK			BIT(7)
+
+#define WLED4_CTRL_REG_SEC_ACCESS			0xd0
+#define  WLED4_CTRL_REG_SEC_UNLOCK			0xa5
+
+#define WLED4_CTRL_REG_TEST1				0xe2
+#define  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2		0x09
+
+/* WLED3 sink registers */
 #define WLED3_SINK_REG_SYNC				0x47
 #define  WLED3_SINK_REG_SYNC_MASK			GENMASK(2, 0)
 #define  WLED4_SINK_REG_SYNC_MASK			GENMASK(3, 0)
@@ -130,17 +145,23 @@ struct wled_config {
 	bool cs_out_en;
 	bool ext_gen;
 	bool cabc;
+	bool external_pfet;
 };
 
 struct wled {
 	const char *name;
 	struct device *dev;
 	struct regmap *regmap;
+	struct mutex lock;	/* Lock to avoid race from ISR */
+	ktime_t last_short_event;
 	u16 ctrl_addr;
 	u16 sink_addr;
 	u32 brightness;
 	u32 max_brightness;
+	u32 short_count;
 	const int *version;
+	int short_irq;
+	bool force_mod_disable;
 
 	struct wled_config cfg;
 	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
@@ -192,6 +213,9 @@ static int wled_module_enable(struct wled *wled, int val)
 {
 	int rc;
 
+	if (wled->force_mod_disable)
+		return 0;
+
 	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
 				WLED3_CTRL_REG_MOD_EN,
 				WLED3_CTRL_REG_MOD_EN_MASK,
@@ -248,12 +272,13 @@ static int wled_update_status(struct backlight_device *bl)
 	    bl->props.state & BL_CORE_FBBLANK)
 		brightness = 0;
 
+	mutex_lock(&wled->lock);
 	if (brightness) {
 		rc = wled->wled_set_brightness(wled, brightness);
 		if (rc < 0) {
 			dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
 				rc);
-			return rc;
+			goto unlock_mutex;
 		}
 
 		rc = wled->wled_sync_toggle(wled);
@@ -267,15 +292,60 @@ static int wled_update_status(struct backlight_device *bl)
 		rc = wled_module_enable(wled, !!brightness);
 		if (rc < 0) {
 			dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
-			return rc;
+			goto unlock_mutex;
 		}
 	}
 
 	wled->brightness = brightness;
 
+unlock_mutex:
+	mutex_unlock(&wled->lock);
+
 	return rc;
 }
 
+#define WLED_SHORT_DLY_MS			20
+#define WLED_SHORT_CNT_MAX			5
+#define WLED_SHORT_RESET_CNT_DLY_US	HZ
+static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
+{
+	struct wled *wled = _wled;
+	int rc;
+	s64 elapsed_time;
+
+	wled->short_count++;
+	mutex_lock(&wled->lock);
+	rc = wled_module_enable(wled, false);
+	if (rc < 0) {
+		dev_err(wled->dev, "wled disable failed rc:%d\n", rc);
+		goto unlock_mutex;
+	}
+
+	elapsed_time = ktime_us_delta(ktime_get(),
+				      wled->last_short_event);
+	if (elapsed_time > WLED_SHORT_RESET_CNT_DLY_US)
+		wled->short_count = 0;
+
+	if (wled->short_count > WLED_SHORT_CNT_MAX) {
+		dev_err(wled->dev, "Short trigged %d times, disabling WLED forever!\n",
+			wled->short_count);
+		wled->force_mod_disable = true;
+		goto unlock_mutex;
+	}
+
+	wled->last_short_event = ktime_get();
+
+	msleep(WLED_SHORT_DLY_MS);
+	rc = wled_module_enable(wled, true);
+	if (rc < 0)
+		dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
+
+unlock_mutex:
+	mutex_unlock(&wled->lock);
+
+	return IRQ_HANDLED;
+}
+
 static int wled3_setup(struct wled *wled)
 {
 	u16 addr;
@@ -435,6 +505,21 @@ static int wled4_setup(struct wled *wled)
 		return rc;
 	}
 
+	if (wled->cfg.external_pfet) {
+		/* Unlock the secure register access */
+		rc = regmap_write(wled->regmap, wled->ctrl_addr +
+				  WLED4_CTRL_REG_SEC_ACCESS,
+				  WLED4_CTRL_REG_SEC_UNLOCK);
+		if (rc < 0)
+			return rc;
+
+		rc = regmap_write(wled->regmap,
+				  wled->ctrl_addr + WLED4_CTRL_REG_TEST1,
+				  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2);
+		if (rc < 0)
+			return rc;
+	}
+
 	return 0;
 }
 
@@ -446,6 +531,7 @@ static int wled4_setup(struct wled *wled)
 	.switch_freq = 11,
 	.enabled_strings = 0xf,
 	.cabc = false,
+	.external_pfet = true,
 };
 
 static const u32 wled3_boost_i_limit_values[] = {
@@ -628,6 +714,7 @@ static int wled_configure(struct wled *wled)
 		{ "qcom,cs-out", &cfg->cs_out_en, },
 		{ "qcom,ext-gen", &cfg->ext_gen, },
 		{ "qcom,cabc", &cfg->cabc, },
+		{ "qcom,external-pfet", &cfg->external_pfet, },
 	};
 
 	prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
@@ -701,6 +788,39 @@ static int wled_configure(struct wled *wled)
 	return 0;
 }
 
+static int wled_configure_short_irq(struct wled *wled,
+				    struct platform_device *pdev)
+{
+	int rc = 0;
+
+	/* PM8941 doesn't have the short detection support */
+	if (*wled->version == WLED_PM8941)
+		return 0;
+
+	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
+				WLED4_CTRL_REG_SHORT_PROTECT,
+				WLED4_CTRL_REG_SHORT_EN_MASK,
+				WLED4_CTRL_REG_SHORT_EN_MASK);
+	if (rc < 0)
+		return rc;
+
+	wled->short_irq = platform_get_irq_byname(pdev, "short");
+	if (wled->short_irq < 0) {
+		dev_dbg(&pdev->dev, "short irq is not used\n");
+		return 0;
+	}
+
+	rc = devm_request_threaded_irq(wled->dev, wled->short_irq,
+				       NULL, wled_short_irq_handler,
+				       IRQF_ONESHOT,
+				       "wled_short_irq", wled);
+	if (rc < 0)
+		dev_err(wled->dev, "Unable to request short_irq (err:%d)\n",
+			rc);
+
+	return rc;
+}
+
 static const struct backlight_ops wled_ops = {
 	.update_status = wled_update_status,
 };
@@ -733,6 +853,8 @@ static int wled_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	mutex_init(&wled->lock);
+
 	rc = wled_configure(wled);
 	if (rc)
 		return rc;
@@ -752,6 +874,10 @@ static int wled_probe(struct platform_device *pdev)
 		}
 	}
 
+	rc = wled_configure_short_irq(wled, pdev);
+	if (rc < 0)
+		return rc;
+
 	val = WLED_DEFAULT_BRIGHTNESS;
 	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

Re: [PATCH V2 3/5] backlight: qcom-wled: Add support for short circuit handling

[Daniel Thompson]

On Thu, May 03, 2018 at 03:42:30PM +0530, Kiran Gunda wrote:
> Handle the short circuit interrupt and check if the short circuit
> interrupt is valid. Re-enable the module to check if it goes
> away. Disable the module altogether if the short circuit event
> persists.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  drivers/video/backlight/qcom-wled.c | 134 ++++++++++++++++++++++++++++++++++--
>  1 file changed, 130 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index be8b8d3..2cfba77 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -10,6 +10,9 @@
>   * GNU General Public License for more details.
>   */
>  
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/ktime.h>
>  #include <linux/kernel.h>
>  #include <linux/backlight.h>
>  #include <linux/module.h>
> @@ -23,7 +26,9 @@
>  
>  #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
>  
> -/* Control registers */
> +/* WLED3 Control registers */
> +#define WLED3_CTRL_REG_FAULT_STATUS			0x08
> +
>  #define WLED3_CTRL_REG_MOD_EN				0x46
>  #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
>  
> @@ -36,7 +41,17 @@
>  #define WLED3_CTRL_REG_ILIMIT				0x4e
>  #define  WLED3_CTRL_REG_ILIMIT_MASK			GENMASK(2, 0)
>  
> -/* sink registers */
> +/* WLED4 control registers */
> +#define WLED4_CTRL_REG_SHORT_PROTECT			0x5e
> +#define  WLED4_CTRL_REG_SHORT_EN_MASK			BIT(7)
> +
> +#define WLED4_CTRL_REG_SEC_ACCESS			0xd0
> +#define  WLED4_CTRL_REG_SEC_UNLOCK			0xa5
> +
> +#define WLED4_CTRL_REG_TEST1				0xe2
> +#define  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2		0x09
> +
> +/* WLED3 sink registers */
>  #define WLED3_SINK_REG_SYNC				0x47
>  #define  WLED3_SINK_REG_SYNC_MASK			GENMASK(2, 0)
>  #define  WLED4_SINK_REG_SYNC_MASK			GENMASK(3, 0)
> @@ -130,17 +145,23 @@ struct wled_config {
>  	bool cs_out_en;
>  	bool ext_gen;
>  	bool cabc;
> +	bool external_pfet;
>  };
>  
>  struct wled {
>  	const char *name;
>  	struct device *dev;
>  	struct regmap *regmap;
> +	struct mutex lock;	/* Lock to avoid race from ISR */
> +	ktime_t last_short_event;
>  	u16 ctrl_addr;
>  	u16 sink_addr;
>  	u32 brightness;
>  	u32 max_brightness;
> +	u32 short_count;
>  	const int *version;
> +	int short_irq;
> +	bool force_mod_disable;
>  
>  	struct wled_config cfg;
>  	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
> @@ -192,6 +213,9 @@ static int wled_module_enable(struct wled *wled, int val)
>  {
>  	int rc;
>  
> +	if (wled->force_mod_disable)
> +		return 0;
> +
>  	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
>  				WLED3_CTRL_REG_MOD_EN,
>  				WLED3_CTRL_REG_MOD_EN_MASK,
> @@ -248,12 +272,13 @@ static int wled_update_status(struct backlight_device *bl)
>  	    bl->props.state & BL_CORE_FBBLANK)
>  		brightness = 0;
>  
> +	mutex_lock(&wled->lock);
>  	if (brightness) {
>  		rc = wled->wled_set_brightness(wled, brightness);
>  		if (rc < 0) {
>  			dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
>  				rc);
> -			return rc;
> +			goto unlock_mutex;
>  		}
>  
>  		rc = wled->wled_sync_toggle(wled);
> @@ -267,15 +292,60 @@ static int wled_update_status(struct backlight_device *bl)
>  		rc = wled_module_enable(wled, !!brightness);
>  		if (rc < 0) {
>  			dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
> -			return rc;
> +			goto unlock_mutex;
>  		}
>  	}
>  
>  	wled->brightness = brightness;
>  
> +unlock_mutex:
> +	mutex_unlock(&wled->lock);
> +
>  	return rc;
>  }
>  
> +#define WLED_SHORT_DLY_MS			20
> +#define WLED_SHORT_CNT_MAX			5
> +#define WLED_SHORT_RESET_CNT_DLY_US	HZ

So we think a short report every quarter second is harmless?


> +static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
> +{
> +	struct wled *wled = _wled;
> +	int rc;
> +	s64 elapsed_time;
> +
> +	wled->short_count++;
> +	mutex_lock(&wled->lock);
> +	rc = wled_module_enable(wled, false);
> +	if (rc < 0) {
> +		dev_err(wled->dev, "wled disable failed rc:%d\n", rc);
> +		goto unlock_mutex;
> +	}
> +
> +	elapsed_time = ktime_us_delta(ktime_get(),
> +				      wled->last_short_event);
> +	if (elapsed_time > WLED_SHORT_RESET_CNT_DLY_US)
> +		wled->short_count = 0;
> +
> +	if (wled->short_count > WLED_SHORT_CNT_MAX) {
> +		dev_err(wled->dev, "Short trigged %d times, disabling WLED forever!\n",
> +			wled->short_count);
> +		wled->force_mod_disable = true;
> +		goto unlock_mutex;
> +	}
> +
> +	wled->last_short_event = ktime_get();
> +
> +	msleep(WLED_SHORT_DLY_MS);
> +	rc = wled_module_enable(wled, true);
> +	if (rc < 0)
> +		dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
> +
> +unlock_mutex:
> +	mutex_unlock(&wled->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int wled3_setup(struct wled *wled)
>  {
>  	u16 addr;
> @@ -435,6 +505,21 @@ static int wled4_setup(struct wled *wled)
>  		return rc;
>  	}
>  
> +	if (wled->cfg.external_pfet) {
> +		/* Unlock the secure register access */
> +		rc = regmap_write(wled->regmap, wled->ctrl_addr +
> +				  WLED4_CTRL_REG_SEC_ACCESS,
> +				  WLED4_CTRL_REG_SEC_UNLOCK);
> +		if (rc < 0)
> +			return rc;
> +
> +		rc = regmap_write(wled->regmap,
> +				  wled->ctrl_addr + WLED4_CTRL_REG_TEST1,
> +				  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2);
> +		if (rc < 0)
> +			return rc;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -446,6 +531,7 @@ static int wled4_setup(struct wled *wled)
>  	.switch_freq = 11,
>  	.enabled_strings = 0xf,
>  	.cabc = false,
> +	.external_pfet = true,
>  };
>  
>  static const u32 wled3_boost_i_limit_values[] = {
> @@ -628,6 +714,7 @@ static int wled_configure(struct wled *wled)
>  		{ "qcom,cs-out", &cfg->cs_out_en, },
>  		{ "qcom,ext-gen", &cfg->ext_gen, },
>  		{ "qcom,cabc", &cfg->cabc, },
> +		{ "qcom,external-pfet", &cfg->external_pfet, },
>  	};
>  
>  	prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
> @@ -701,6 +788,39 @@ static int wled_configure(struct wled *wled)
>  	return 0;
>  }
>  
> +static int wled_configure_short_irq(struct wled *wled,
> +				    struct platform_device *pdev)
> +{
> +	int rc = 0;
> +
> +	/* PM8941 doesn't have the short detection support */
> +	if (*wled->version == WLED_PM8941)
> +		return 0;
> +
> +	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> +				WLED4_CTRL_REG_SHORT_PROTECT,
> +				WLED4_CTRL_REG_SHORT_EN_MASK,
> +				WLED4_CTRL_REG_SHORT_EN_MASK);
> +	if (rc < 0)
> +		return rc;
> +
> +	wled->short_irq = platform_get_irq_byname(pdev, "short");
> +	if (wled->short_irq < 0) {
> +		dev_dbg(&pdev->dev, "short irq is not used\n");
> +		return 0;
> +	}
> +
> +	rc = devm_request_threaded_irq(wled->dev, wled->short_irq,
> +				       NULL, wled_short_irq_handler,

NULL? There's no register we can check to make sure the interrupt
handler did not enter spuriously?


> +				       IRQF_ONESHOT,
> +				       "wled_short_irq", wled);
> +	if (rc < 0)
> +		dev_err(wled->dev, "Unable to request short_irq (err:%d)\n",
> +			rc);
> +
> +	return rc;
> +}
> +
>  static const struct backlight_ops wled_ops = {
>  	.update_status = wled_update_status,
>  };
> @@ -733,6 +853,8 @@ static int wled_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> +	mutex_init(&wled->lock);
> +
>  	rc = wled_configure(wled);
>  	if (rc)
>  		return rc;
> @@ -752,6 +874,10 @@ static int wled_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	rc = wled_configure_short_irq(wled, pdev);
> +	if (rc < 0)
> +		return rc;
> +
>  	val = WLED_DEFAULT_BRIGHTNESS;
>  	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
>  
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project
> 

Re: [PATCH V2 3/5] backlight: qcom-wled: Add support for short circuit handling

[kgunda]

On 2018-05-08 16:05, Daniel Thompson wrote:
> On Thu, May 03, 2018 at 03:42:30PM +0530, Kiran Gunda wrote:
>> Handle the short circuit interrupt and check if the short circuit
>> interrupt is valid. Re-enable the module to check if it goes
>> away. Disable the module altogether if the short circuit event
>> persists.
>> 
>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> ---
>>  drivers/video/backlight/qcom-wled.c | 134 
>> ++++++++++++++++++++++++++++++++++--
>>  1 file changed, 130 insertions(+), 4 deletions(-)
>> 
>> diff --git a/drivers/video/backlight/qcom-wled.c 
>> b/drivers/video/backlight/qcom-wled.c
>> index be8b8d3..2cfba77 100644
>> --- a/drivers/video/backlight/qcom-wled.c
>> +++ b/drivers/video/backlight/qcom-wled.c
>> @@ -10,6 +10,9 @@
>>   * GNU General Public License for more details.
>>   */
>> 
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/ktime.h>
>>  #include <linux/kernel.h>
>>  #include <linux/backlight.h>
>>  #include <linux/module.h>
>> @@ -23,7 +26,9 @@
>> 
>>  #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
>> 
>> -/* Control registers */
>> +/* WLED3 Control registers */
>> +#define WLED3_CTRL_REG_FAULT_STATUS			0x08
>> +
>>  #define WLED3_CTRL_REG_MOD_EN				0x46
>>  #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
>> 
>> @@ -36,7 +41,17 @@
>>  #define WLED3_CTRL_REG_ILIMIT				0x4e
>>  #define  WLED3_CTRL_REG_ILIMIT_MASK			GENMASK(2, 0)
>> 
>> -/* sink registers */
>> +/* WLED4 control registers */
>> +#define WLED4_CTRL_REG_SHORT_PROTECT			0x5e
>> +#define  WLED4_CTRL_REG_SHORT_EN_MASK			BIT(7)
>> +
>> +#define WLED4_CTRL_REG_SEC_ACCESS			0xd0
>> +#define  WLED4_CTRL_REG_SEC_UNLOCK			0xa5
>> +
>> +#define WLED4_CTRL_REG_TEST1				0xe2
>> +#define  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2		0x09
>> +
>> +/* WLED3 sink registers */
>>  #define WLED3_SINK_REG_SYNC				0x47
>>  #define  WLED3_SINK_REG_SYNC_MASK			GENMASK(2, 0)
>>  #define  WLED4_SINK_REG_SYNC_MASK			GENMASK(3, 0)
>> @@ -130,17 +145,23 @@ struct wled_config {
>>  	bool cs_out_en;
>>  	bool ext_gen;
>>  	bool cabc;
>> +	bool external_pfet;
>>  };
>> 
>>  struct wled {
>>  	const char *name;
>>  	struct device *dev;
>>  	struct regmap *regmap;
>> +	struct mutex lock;	/* Lock to avoid race from ISR */
>> +	ktime_t last_short_event;
>>  	u16 ctrl_addr;
>>  	u16 sink_addr;
>>  	u32 brightness;
>>  	u32 max_brightness;
>> +	u32 short_count;
>>  	const int *version;
>> +	int short_irq;
>> +	bool force_mod_disable;
>> 
>>  	struct wled_config cfg;
>>  	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
>> @@ -192,6 +213,9 @@ static int wled_module_enable(struct wled *wled, 
>> int val)
>>  {
>>  	int rc;
>> 
>> +	if (wled->force_mod_disable)
>> +		return 0;
>> +
>>  	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
>>  				WLED3_CTRL_REG_MOD_EN,
>>  				WLED3_CTRL_REG_MOD_EN_MASK,
>> @@ -248,12 +272,13 @@ static int wled_update_status(struct 
>> backlight_device *bl)
>>  	    bl->props.state & BL_CORE_FBBLANK)
>>  		brightness = 0;
>> 
>> +	mutex_lock(&wled->lock);
>>  	if (brightness) {
>>  		rc = wled->wled_set_brightness(wled, brightness);
>>  		if (rc < 0) {
>>  			dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
>>  				rc);
>> -			return rc;
>> +			goto unlock_mutex;
>>  		}
>> 
>>  		rc = wled->wled_sync_toggle(wled);
>> @@ -267,15 +292,60 @@ static int wled_update_status(struct 
>> backlight_device *bl)
>>  		rc = wled_module_enable(wled, !!brightness);
>>  		if (rc < 0) {
>>  			dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
>> -			return rc;
>> +			goto unlock_mutex;
>>  		}
>>  	}
>> 
>>  	wled->brightness = brightness;
>> 
>> +unlock_mutex:
>> +	mutex_unlock(&wled->lock);
>> +
>>  	return rc;
>>  }
>> 
>> +#define WLED_SHORT_DLY_MS			20
>> +#define WLED_SHORT_CNT_MAX			5
>> +#define WLED_SHORT_RESET_CNT_DLY_US	HZ
> 
> So we think a short report every quarter second is harmless?
> 
> 
Yes. We wait for the short to report 5 times with in this time. If the 
short
still persists, we go and disable the WLED module to avoid the damage. 
This is
suggested by the HW team.

>> +static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
>> +{
>> +	struct wled *wled = _wled;
>> +	int rc;
>> +	s64 elapsed_time;
>> +
>> +	wled->short_count++;
>> +	mutex_lock(&wled->lock);
>> +	rc = wled_module_enable(wled, false);
>> +	if (rc < 0) {
>> +		dev_err(wled->dev, "wled disable failed rc:%d\n", rc);
>> +		goto unlock_mutex;
>> +	}
>> +
>> +	elapsed_time = ktime_us_delta(ktime_get(),
>> +				      wled->last_short_event);
>> +	if (elapsed_time > WLED_SHORT_RESET_CNT_DLY_US)
>> +		wled->short_count = 0;
>> +
>> +	if (wled->short_count > WLED_SHORT_CNT_MAX) {
>> +		dev_err(wled->dev, "Short trigged %d times, disabling WLED 
>> forever!\n",
>> +			wled->short_count);
>> +		wled->force_mod_disable = true;
>> +		goto unlock_mutex;
>> +	}
>> +
>> +	wled->last_short_event = ktime_get();
>> +
>> +	msleep(WLED_SHORT_DLY_MS);
>> +	rc = wled_module_enable(wled, true);
>> +	if (rc < 0)
>> +		dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
>> +
>> +unlock_mutex:
>> +	mutex_unlock(&wled->lock);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>>  static int wled3_setup(struct wled *wled)
>>  {
>>  	u16 addr;
>> @@ -435,6 +505,21 @@ static int wled4_setup(struct wled *wled)
>>  		return rc;
>>  	}
>> 
>> +	if (wled->cfg.external_pfet) {
>> +		/* Unlock the secure register access */
>> +		rc = regmap_write(wled->regmap, wled->ctrl_addr +
>> +				  WLED4_CTRL_REG_SEC_ACCESS,
>> +				  WLED4_CTRL_REG_SEC_UNLOCK);
>> +		if (rc < 0)
>> +			return rc;
>> +
>> +		rc = regmap_write(wled->regmap,
>> +				  wled->ctrl_addr + WLED4_CTRL_REG_TEST1,
>> +				  WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2);
>> +		if (rc < 0)
>> +			return rc;
>> +	}
>> +
>>  	return 0;
>>  }
>> 
>> @@ -446,6 +531,7 @@ static int wled4_setup(struct wled *wled)
>>  	.switch_freq = 11,
>>  	.enabled_strings = 0xf,
>>  	.cabc = false,
>> +	.external_pfet = true,
>>  };
>> 
>>  static const u32 wled3_boost_i_limit_values[] = {
>> @@ -628,6 +714,7 @@ static int wled_configure(struct wled *wled)
>>  		{ "qcom,cs-out", &cfg->cs_out_en, },
>>  		{ "qcom,ext-gen", &cfg->ext_gen, },
>>  		{ "qcom,cabc", &cfg->cabc, },
>> +		{ "qcom,external-pfet", &cfg->external_pfet, },
>>  	};
>> 
>>  	prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
>> @@ -701,6 +788,39 @@ static int wled_configure(struct wled *wled)
>>  	return 0;
>>  }
>> 
>> +static int wled_configure_short_irq(struct wled *wled,
>> +				    struct platform_device *pdev)
>> +{
>> +	int rc = 0;
>> +
>> +	/* PM8941 doesn't have the short detection support */
>> +	if (*wled->version == WLED_PM8941)
>> +		return 0;
>> +
>> +	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
>> +				WLED4_CTRL_REG_SHORT_PROTECT,
>> +				WLED4_CTRL_REG_SHORT_EN_MASK,
>> +				WLED4_CTRL_REG_SHORT_EN_MASK);
>> +	if (rc < 0)
>> +		return rc;
>> +
>> +	wled->short_irq = platform_get_irq_byname(pdev, "short");
>> +	if (wled->short_irq < 0) {
>> +		dev_dbg(&pdev->dev, "short irq is not used\n");
>> +		return 0;
>> +	}
>> +
>> +	rc = devm_request_threaded_irq(wled->dev, wled->short_irq,
>> +				       NULL, wled_short_irq_handler,
> 
> NULL? There's no register we can check to make sure the interrupt
> handler did not enter spuriously?
> 
> 
There is FAULT_STATUS register. I will address it in the next series.

>> +				       IRQF_ONESHOT,
>> +				       "wled_short_irq", wled);
>> +	if (rc < 0)
>> +		dev_err(wled->dev, "Unable to request short_irq (err:%d)\n",
>> +			rc);
>> +
>> +	return rc;
>> +}
>> +
>>  static const struct backlight_ops wled_ops = {
>>  	.update_status = wled_update_status,
>>  };
>> @@ -733,6 +853,8 @@ static int wled_probe(struct platform_device 
>> *pdev)
>>  		return -ENODEV;
>>  	}
>> 
>> +	mutex_init(&wled->lock);
>> +
>>  	rc = wled_configure(wled);
>>  	if (rc)
>>  		return rc;
>> @@ -752,6 +874,10 @@ static int wled_probe(struct platform_device 
>> *pdev)
>>  		}
>>  	}
>> 
>> +	rc = wled_configure_short_irq(wled, pdev);
>> +	if (rc < 0)
>> +		return rc;
>> +
>>  	val = WLED_DEFAULT_BRIGHTNESS;
>>  	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
>> 
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>>  a Linux Foundation Collaborative Project
>> 

[PATCH V2 4/5] backlight: qcom-wled: Add support for OVP interrupt handling

[Kiran Gunda]

WLED peripheral has over voltage protection(OVP) circuitry and the OVP
fault is notified through an interrupt. Though this fault condition rising
is due to an incorrect hardware configuration is mitigated in the hardware,
it still needs to be detected and handled. Add support for it.

When WLED module is enabled, keep OVP fault interrupt disabled for 10 ms to
account for soft start delay.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 drivers/video/backlight/qcom-wled.c | 118 +++++++++++++++++++++++++++++++++++-
 1 file changed, 116 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 2cfba77..80ae084 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -23,14 +23,20 @@
 
 /* From DT binding */
 #define WLED_DEFAULT_BRIGHTNESS				2048
-
+#define WLED_SOFT_START_DLY_US				10000
 #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
 
 /* WLED3 Control registers */
 #define WLED3_CTRL_REG_FAULT_STATUS			0x08
+#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 WLED3_CTRL_REG_INT_RT_STS			0x10
 
 #define WLED3_CTRL_REG_MOD_EN				0x46
 #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
+#define  WLED3_CTRL_REG_MOD_EN_BIT			BIT(7)
 
 #define WLED3_CTRL_REG_FREQ				0x4c
 #define  WLED3_CTRL_REG_FREQ_MASK			GENMASK(3, 0)
@@ -161,9 +167,12 @@ struct wled {
 	u32 short_count;
 	const int *version;
 	int short_irq;
+	int ovp_irq;
 	bool force_mod_disable;
+	bool ovp_irq_disabled;
 
 	struct wled_config cfg;
+	struct delayed_work ovp_work;
 	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
 	int (*wled_sync_toggle)(struct wled *wled);
 };
@@ -209,6 +218,32 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
 	return 0;
 }
 
+static void wled_ovp_work(struct work_struct *work)
+{
+	u32 val;
+	int rc;
+
+	struct wled *wled = container_of(work,
+					 struct wled, ovp_work.work);
+
+	rc = regmap_read(wled->regmap, wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN,
+			 &val);
+	if (rc < 0)
+		return;
+
+	if (val & WLED3_CTRL_REG_MOD_EN_BIT) {
+		if (wled->ovp_irq > 0 && wled->ovp_irq_disabled) {
+			enable_irq(wled->ovp_irq);
+			wled->ovp_irq_disabled = false;
+		}
+	} else {
+		if (wled->ovp_irq > 0 && !wled->ovp_irq_disabled) {
+			disable_irq(wled->ovp_irq);
+			wled->ovp_irq_disabled = true;
+		}
+	}
+}
+
 static int wled_module_enable(struct wled *wled, int val)
 {
 	int rc;
@@ -220,7 +255,12 @@ static int wled_module_enable(struct wled *wled, int val)
 				WLED3_CTRL_REG_MOD_EN,
 				WLED3_CTRL_REG_MOD_EN_MASK,
 				WLED3_CTRL_REG_MOD_EN_MASK);
-	return rc;
+	if (rc < 0)
+		return rc;
+
+	schedule_delayed_work(&wled->ovp_work, WLED_SOFT_START_DLY_US);
+
+	return 0;
 }
 
 static int wled3_sync_toggle(struct wled *wled)
@@ -346,6 +386,36 @@ static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
+{
+	struct wled *wled = _wled;
+	int rc;
+	u32 int_sts, fault_sts;
+
+	rc = regmap_read(wled->regmap,
+			 wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, &int_sts);
+	if (rc < 0) {
+		dev_err(wled->dev, "Error in reading WLED3_INT_RT_STS rc=%d\n",
+			rc);
+		return IRQ_HANDLED;
+	}
+
+	rc = regmap_read(wled->regmap, wled->ctrl_addr +
+			 WLED3_CTRL_REG_FAULT_STATUS, &fault_sts);
+	if (rc < 0) {
+		dev_err(wled->dev, "Error in reading WLED_FAULT_STATUS rc=%d\n",
+			rc);
+		return IRQ_HANDLED;
+	}
+
+	if (fault_sts &
+		(WLED3_CTRL_REG_OVP_FAULT_BIT | WLED3_CTRL_REG_ILIM_FAULT_BIT))
+		dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x fault_sts= %x\n",
+			int_sts, fault_sts);
+
+	return IRQ_HANDLED;
+}
+
 static int wled3_setup(struct wled *wled)
 {
 	u16 addr;
@@ -821,6 +891,44 @@ static int wled_configure_short_irq(struct wled *wled,
 	return rc;
 }
 
+static int wled_configure_ovp_irq(struct wled *wled,
+				  struct platform_device *pdev)
+{
+	int rc = 0;
+	u32 val;
+
+	if (*wled->version == WLED_PM8941)
+		return 0;
+
+	wled->ovp_irq = platform_get_irq_byname(pdev, "ovp");
+	if (wled->ovp_irq < 0) {
+		dev_dbg(&pdev->dev, "ovp irq is not used\n");
+		return 0;
+	}
+
+	rc = devm_request_threaded_irq(wled->dev, wled->ovp_irq, NULL,
+				       wled_ovp_irq_handler, IRQF_ONESHOT,
+				       "wled_ovp_irq", wled);
+	if (rc < 0) {
+		dev_err(wled->dev, "Unable to request ovp_irq (err:%d)\n",
+			rc);
+		return 0;
+	}
+
+	rc = regmap_read(wled->regmap, wled->ctrl_addr +
+			 WLED3_CTRL_REG_MOD_EN, &val);
+	if (rc < 0)
+		return rc;
+
+	/* Keep OVP irq disabled until module is enabled */
+	if (!rc && !(val & WLED3_CTRL_REG_MOD_EN_MASK)) {
+		disable_irq(wled->ovp_irq);
+		wled->ovp_irq_disabled = true;
+	}
+
+	return rc;
+}
+
 static const struct backlight_ops wled_ops = {
 	.update_status = wled_update_status,
 };
@@ -874,10 +982,16 @@ static int wled_probe(struct platform_device *pdev)
 		}
 	}
 
+	INIT_DELAYED_WORK(&wled->ovp_work, wled_ovp_work);
+
 	rc = wled_configure_short_irq(wled, pdev);
 	if (rc < 0)
 		return rc;
 
+	rc = wled_configure_ovp_irq(wled, pdev);
+	if (rc < 0)
+		return rc;
+
 	val = WLED_DEFAULT_BRIGHTNESS;
 	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
 a Linux Foundation Collaborative Project

Re: [PATCH V2 4/5] backlight: qcom-wled: Add support for OVP interrupt handling

[Daniel Thompson]

On Thu, May 03, 2018 at 03:42:31PM +0530, Kiran Gunda wrote:
> WLED peripheral has over voltage protection(OVP) circuitry and the OVP
> fault is notified through an interrupt. Though this fault condition rising
> is due to an incorrect hardware configuration is mitigated in the hardware,
> it still needs to be detected and handled. Add support for it.

Why detect and handle it? The interrupt handler doesn't appear to do
anything other than clear the interrupt... and it appears that the 
interrupt can be masked.


> When WLED module is enabled, keep OVP fault interrupt disabled for 10 ms to
> account for soft start delay.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
>  drivers/video/backlight/qcom-wled.c | 118 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 116 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 2cfba77..80ae084 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -23,14 +23,20 @@
>  
>  /* From DT binding */
>  #define WLED_DEFAULT_BRIGHTNESS				2048
> -
> +#define WLED_SOFT_START_DLY_US				10000
>  #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
>  
>  /* WLED3 Control registers */
>  #define WLED3_CTRL_REG_FAULT_STATUS			0x08
> +#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 WLED3_CTRL_REG_INT_RT_STS			0x10
>  
>  #define WLED3_CTRL_REG_MOD_EN				0x46
>  #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
> +#define  WLED3_CTRL_REG_MOD_EN_BIT			BIT(7)
>  
>  #define WLED3_CTRL_REG_FREQ				0x4c
>  #define  WLED3_CTRL_REG_FREQ_MASK			GENMASK(3, 0)
> @@ -161,9 +167,12 @@ struct wled {
>  	u32 short_count;
>  	const int *version;
>  	int short_irq;
> +	int ovp_irq;
>  	bool force_mod_disable;
> +	bool ovp_irq_disabled;
>  
>  	struct wled_config cfg;
> +	struct delayed_work ovp_work;
>  	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
>  	int (*wled_sync_toggle)(struct wled *wled);
>  };
> @@ -209,6 +218,32 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
>  	return 0;
>  }
>  
> +static void wled_ovp_work(struct work_struct *work)
> +{
> +	u32 val;
> +	int rc;
> +
> +	struct wled *wled = container_of(work,
> +					 struct wled, ovp_work.work);
> +
> +	rc = regmap_read(wled->regmap, wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN,
> +			 &val);
> +	if (rc < 0)
> +		return;
> +
> +	if (val & WLED3_CTRL_REG_MOD_EN_BIT) {
> +		if (wled->ovp_irq > 0 && wled->ovp_irq_disabled) {
> +			enable_irq(wled->ovp_irq);
> +			wled->ovp_irq_disabled = false;
> +		}
> +	} else {
> +		if (wled->ovp_irq > 0 && !wled->ovp_irq_disabled) {
> +			disable_irq(wled->ovp_irq);
> +			wled->ovp_irq_disabled = true;
> +		}
> +	}
> +}
> +
>  static int wled_module_enable(struct wled *wled, int val)
>  {
>  	int rc;
> @@ -220,7 +255,12 @@ static int wled_module_enable(struct wled *wled, int val)
>  				WLED3_CTRL_REG_MOD_EN,
>  				WLED3_CTRL_REG_MOD_EN_MASK,
>  				WLED3_CTRL_REG_MOD_EN_MASK);
> -	return rc;
> +	if (rc < 0)
> +		return rc;
> +
> +	schedule_delayed_work(&wled->ovp_work, WLED_SOFT_START_DLY_US);
> +
> +	return 0;
>  }
>  
>  static int wled3_sync_toggle(struct wled *wled)
> @@ -346,6 +386,36 @@ static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
>  	return IRQ_HANDLED;
>  }
>  
> +static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
> +{
> +	struct wled *wled = _wled;
> +	int rc;
> +	u32 int_sts, fault_sts;
> +
> +	rc = regmap_read(wled->regmap,
> +			 wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, &int_sts);
> +	if (rc < 0) {
> +		dev_err(wled->dev, "Error in reading WLED3_INT_RT_STS rc=%d\n",
> +			rc);
> +		return IRQ_HANDLED;
> +	}
> +
> +	rc = regmap_read(wled->regmap, wled->ctrl_addr +
> +			 WLED3_CTRL_REG_FAULT_STATUS, &fault_sts);
> +	if (rc < 0) {
> +		dev_err(wled->dev, "Error in reading WLED_FAULT_STATUS rc=%d\n",
> +			rc);
> +		return IRQ_HANDLED;
> +	}
> +
> +	if (fault_sts &
> +		(WLED3_CTRL_REG_OVP_FAULT_BIT | WLED3_CTRL_REG_ILIM_FAULT_BIT))
> +		dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x fault_sts= %x\n",
> +			int_sts, fault_sts);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int wled3_setup(struct wled *wled)
>  {
>  	u16 addr;
> @@ -821,6 +891,44 @@ static int wled_configure_short_irq(struct wled *wled,
>  	return rc;
>  }
>  
> +static int wled_configure_ovp_irq(struct wled *wled,
> +				  struct platform_device *pdev)
> +{
> +	int rc = 0;
> +	u32 val;
> +
> +	if (*wled->version == WLED_PM8941)
> +		return 0;
> +
> +	wled->ovp_irq = platform_get_irq_byname(pdev, "ovp");
> +	if (wled->ovp_irq < 0) {
> +		dev_dbg(&pdev->dev, "ovp irq is not used\n");
> +		return 0;
> +	}
> +
> +	rc = devm_request_threaded_irq(wled->dev, wled->ovp_irq, NULL,
> +				       wled_ovp_irq_handler, IRQF_ONESHOT,
> +				       "wled_ovp_irq", wled);
> +	if (rc < 0) {
> +		dev_err(wled->dev, "Unable to request ovp_irq (err:%d)\n",
> +			rc);
> +		return 0;
> +	}
> +
> +	rc = regmap_read(wled->regmap, wled->ctrl_addr +
> +			 WLED3_CTRL_REG_MOD_EN, &val);
> +	if (rc < 0)
> +		return rc;
> +
> +	/* Keep OVP irq disabled until module is enabled */
> +	if (!rc && !(val & WLED3_CTRL_REG_MOD_EN_MASK)) {
> +		disable_irq(wled->ovp_irq);
> +		wled->ovp_irq_disabled = true;
> +	}
> +
> +	return rc;
> +}
> +
>  static const struct backlight_ops wled_ops = {
>  	.update_status = wled_update_status,
>  };
> @@ -874,10 +982,16 @@ static int wled_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	INIT_DELAYED_WORK(&wled->ovp_work, wled_ovp_work);
> +
>  	rc = wled_configure_short_irq(wled, pdev);
>  	if (rc < 0)
>  		return rc;
>  
> +	rc = wled_configure_ovp_irq(wled, pdev);
> +	if (rc < 0)
> +		return rc;
> +
>  	val = WLED_DEFAULT_BRIGHTNESS;
>  	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
>  
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project
> 

Re: [PATCH V2 4/5] backlight: qcom-wled: Add support for OVP interrupt handling

[kgunda]

On 2018-05-08 16:09, Daniel Thompson wrote:
> On Thu, May 03, 2018 at 03:42:31PM +0530, Kiran Gunda wrote:
>> WLED peripheral has over voltage protection(OVP) circuitry and the OVP
>> fault is notified through an interrupt. Though this fault condition 
>> rising
>> is due to an incorrect hardware configuration is mitigated in the 
>> hardware,
>> it still needs to be detected and handled. Add support for it.
> 
> Why detect and handle it? The interrupt handler doesn't appear to do
> anything other than clear the interrupt... and it appears that the
> interrupt can be masked.
> 
> 
Planing to squash this patch with the auto-string-detection patch in the 
next series,
where the OVP is used for the right string detection.
>> When WLED module is enabled, keep OVP fault interrupt disabled for 10 
>> ms to
>> account for soft start delay.
>> 
>> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
>> ---
>>  drivers/video/backlight/qcom-wled.c | 118 
>> +++++++++++++++++++++++++++++++++++-
>>  1 file changed, 116 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/video/backlight/qcom-wled.c 
>> b/drivers/video/backlight/qcom-wled.c
>> index 2cfba77..80ae084 100644
>> --- a/drivers/video/backlight/qcom-wled.c
>> +++ b/drivers/video/backlight/qcom-wled.c
>> @@ -23,14 +23,20 @@
>> 
>>  /* From DT binding */
>>  #define WLED_DEFAULT_BRIGHTNESS				2048
>> -
>> +#define WLED_SOFT_START_DLY_US				10000
>>  #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
>> 
>>  /* WLED3 Control registers */
>>  #define WLED3_CTRL_REG_FAULT_STATUS			0x08
>> +#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 WLED3_CTRL_REG_INT_RT_STS			0x10
>> 
>>  #define WLED3_CTRL_REG_MOD_EN				0x46
>>  #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
>> +#define  WLED3_CTRL_REG_MOD_EN_BIT			BIT(7)
>> 
>>  #define WLED3_CTRL_REG_FREQ				0x4c
>>  #define  WLED3_CTRL_REG_FREQ_MASK			GENMASK(3, 0)
>> @@ -161,9 +167,12 @@ struct wled {
>>  	u32 short_count;
>>  	const int *version;
>>  	int short_irq;
>> +	int ovp_irq;
>>  	bool force_mod_disable;
>> +	bool ovp_irq_disabled;
>> 
>>  	struct wled_config cfg;
>> +	struct delayed_work ovp_work;
>>  	int (*wled_set_brightness)(struct wled *wled, u16 brightness);
>>  	int (*wled_sync_toggle)(struct wled *wled);
>>  };
>> @@ -209,6 +218,32 @@ static int wled4_set_brightness(struct wled 
>> *wled, u16 brightness)
>>  	return 0;
>>  }
>> 
>> +static void wled_ovp_work(struct work_struct *work)
>> +{
>> +	u32 val;
>> +	int rc;
>> +
>> +	struct wled *wled = container_of(work,
>> +					 struct wled, ovp_work.work);
>> +
>> +	rc = regmap_read(wled->regmap, wled->ctrl_addr + 
>> WLED3_CTRL_REG_MOD_EN,
>> +			 &val);
>> +	if (rc < 0)
>> +		return;
>> +
>> +	if (val & WLED3_CTRL_REG_MOD_EN_BIT) {
>> +		if (wled->ovp_irq > 0 && wled->ovp_irq_disabled) {
>> +			enable_irq(wled->ovp_irq);
>> +			wled->ovp_irq_disabled = false;
>> +		}
>> +	} else {
>> +		if (wled->ovp_irq > 0 && !wled->ovp_irq_disabled) {
>> +			disable_irq(wled->ovp_irq);
>> +			wled->ovp_irq_disabled = true;
>> +		}
>> +	}
>> +}
>> +
>>  static int wled_module_enable(struct wled *wled, int val)
>>  {
>>  	int rc;
>> @@ -220,7 +255,12 @@ static int wled_module_enable(struct wled *wled, 
>> int val)
>>  				WLED3_CTRL_REG_MOD_EN,
>>  				WLED3_CTRL_REG_MOD_EN_MASK,
>>  				WLED3_CTRL_REG_MOD_EN_MASK);
>> -	return rc;
>> +	if (rc < 0)
>> +		return rc;
>> +
>> +	schedule_delayed_work(&wled->ovp_work, WLED_SOFT_START_DLY_US);
>> +
>> +	return 0;
>>  }
>> 
>>  static int wled3_sync_toggle(struct wled *wled)
>> @@ -346,6 +386,36 @@ static irqreturn_t wled_short_irq_handler(int 
>> irq, void *_wled)
>>  	return IRQ_HANDLED;
>>  }
>> 
>> +static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
>> +{
>> +	struct wled *wled = _wled;
>> +	int rc;
>> +	u32 int_sts, fault_sts;
>> +
>> +	rc = regmap_read(wled->regmap,
>> +			 wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, &int_sts);
>> +	if (rc < 0) {
>> +		dev_err(wled->dev, "Error in reading WLED3_INT_RT_STS rc=%d\n",
>> +			rc);
>> +		return IRQ_HANDLED;
>> +	}
>> +
>> +	rc = regmap_read(wled->regmap, wled->ctrl_addr +
>> +			 WLED3_CTRL_REG_FAULT_STATUS, &fault_sts);
>> +	if (rc < 0) {
>> +		dev_err(wled->dev, "Error in reading WLED_FAULT_STATUS rc=%d\n",
>> +			rc);
>> +		return IRQ_HANDLED;
>> +	}
>> +
>> +	if (fault_sts &
>> +		(WLED3_CTRL_REG_OVP_FAULT_BIT | WLED3_CTRL_REG_ILIM_FAULT_BIT))
>> +		dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x fault_sts= 
>> %x\n",
>> +			int_sts, fault_sts);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>>  static int wled3_setup(struct wled *wled)
>>  {
>>  	u16 addr;
>> @@ -821,6 +891,44 @@ static int wled_configure_short_irq(struct wled 
>> *wled,
>>  	return rc;
>>  }
>> 
>> +static int wled_configure_ovp_irq(struct wled *wled,
>> +				  struct platform_device *pdev)
>> +{
>> +	int rc = 0;
>> +	u32 val;
>> +
>> +	if (*wled->version == WLED_PM8941)
>> +		return 0;
>> +
>> +	wled->ovp_irq = platform_get_irq_byname(pdev, "ovp");
>> +	if (wled->ovp_irq < 0) {
>> +		dev_dbg(&pdev->dev, "ovp irq is not used\n");
>> +		return 0;
>> +	}
>> +
>> +	rc = devm_request_threaded_irq(wled->dev, wled->ovp_irq, NULL,
>> +				       wled_ovp_irq_handler, IRQF_ONESHOT,
>> +				       "wled_ovp_irq", wled);
>> +	if (rc < 0) {
>> +		dev_err(wled->dev, "Unable to request ovp_irq (err:%d)\n",
>> +			rc);
>> +		return 0;
>> +	}
>> +
>> +	rc = regmap_read(wled->regmap, wled->ctrl_addr +
>> +			 WLED3_CTRL_REG_MOD_EN, &val);
>> +	if (rc < 0)
>> +		return rc;
>> +
>> +	/* Keep OVP irq disabled until module is enabled */
>> +	if (!rc && !(val & WLED3_CTRL_REG_MOD_EN_MASK)) {
>> +		disable_irq(wled->ovp_irq);
>> +		wled->ovp_irq_disabled = true;
>> +	}
>> +
>> +	return rc;
>> +}
>> +
>>  static const struct backlight_ops wled_ops = {
>>  	.update_status = wled_update_status,
>>  };
>> @@ -874,10 +982,16 @@ static int wled_probe(struct platform_device 
>> *pdev)
>>  		}
>>  	}
>> 
>> +	INIT_DELAYED_WORK(&wled->ovp_work, wled_ovp_work);
>> +
>>  	rc = wled_configure_short_irq(wled, pdev);
>>  	if (rc < 0)
>>  		return rc;
>> 
>> +	rc = wled_configure_ovp_irq(wled, pdev);
>> +	if (rc < 0)
>> +		return rc;
>> +
>>  	val = WLED_DEFAULT_BRIGHTNESS;
>>  	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
>> 
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>>  a Linux Foundation Collaborative Project
>> 

[PATCH V2 5/5] backlight: qcom-wled: Add auto string detection logic

[Kiran Gunda]

The auto string detection algorithm checks if the current WLED
sink configuration is valid. It tries enabling every sink and
checks if the OVP fault is observed. Based on this information
it detects and enables the valid sink configuration.
Auto calibration will be triggered when the OVP fault interrupts
are seen frequently thereby it tries to fix the sink configuration.

Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
---
 drivers/video/backlight/qcom-wled.c | 302 ++++++++++++++++++++++++++++++++++++
 1 file changed, 302 insertions(+)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 80ae084..bacdf3f 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -33,11 +33,14 @@
 #define  WLED4_CTRL_REG_SC_FAULT_BIT			BIT(2)
 
 #define WLED3_CTRL_REG_INT_RT_STS			0x10
+#define  WLED3_CTRL_REG_OVP_FAULT_STATUS		BIT(1)
 
 #define WLED3_CTRL_REG_MOD_EN				0x46
 #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
 #define  WLED3_CTRL_REG_MOD_EN_BIT			BIT(7)
 
+#define WLED3_CTRL_REG_FEEDBACK_CONTROL			0x48
+
 #define WLED3_CTRL_REG_FREQ				0x4c
 #define  WLED3_CTRL_REG_FREQ_MASK			GENMASK(3, 0)
 
@@ -152,6 +155,7 @@ struct wled_config {
 	bool ext_gen;
 	bool cabc;
 	bool external_pfet;
+	bool auto_detection_enabled;
 };
 
 struct wled {
@@ -160,8 +164,10 @@ struct wled {
 	struct regmap *regmap;
 	struct mutex lock;	/* Lock to avoid race from ISR */
 	ktime_t last_short_event;
+	ktime_t start_ovp_fault_time;
 	u16 ctrl_addr;
 	u16 sink_addr;
+	u16 auto_detection_ovp_count;
 	u32 brightness;
 	u32 max_brightness;
 	u32 short_count;
@@ -170,6 +176,7 @@ struct wled {
 	int ovp_irq;
 	bool force_mod_disable;
 	bool ovp_irq_disabled;
+	bool auto_detection_done;
 
 	struct wled_config cfg;
 	struct delayed_work ovp_work;
@@ -386,6 +393,292 @@ static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
 	return IRQ_HANDLED;
 }
 
+#define AUTO_DETECT_BRIGHTNESS		200
+static int wled_auto_string_detection(struct wled *wled)
+{
+	int rc = 0, i;
+	u32 sink_config = 0, int_sts;
+	u8 sink_test = 0, sink_valid = 0, val;
+
+	if (wled->auto_detection_done)
+		return 0;
+
+	/* read configured sink configuration */
+	rc = regmap_read(wled->regmap, wled->sink_addr +
+			 WLED4_SINK_REG_CURR_SINK, &sink_config);
+	if (rc < 0) {
+		pr_err("Failed to read SINK configuration rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	/* disable the module before starting detection */
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN,
+				WLED3_CTRL_REG_MOD_EN_MASK, 0);
+	if (rc < 0) {
+		pr_err("Failed to disable WLED module rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	/* set low brightness across all sinks */
+	rc = wled4_set_brightness(wled, AUTO_DETECT_BRIGHTNESS);
+	if (rc < 0) {
+		pr_err("Failed to set brightness for auto detection rc=%d\n",
+		       rc);
+		goto failed_detect;
+	}
+
+	if (wled->cfg.cabc) {
+		for (i = 0; i < wled->cfg.num_strings; i++) {
+			rc = regmap_update_bits(wled->regmap, wled->sink_addr +
+						WLED4_SINK_REG_STR_CABC(i),
+						WLED4_SINK_REG_STR_CABC_MASK,
+						0);
+			if (rc < 0)
+				goto failed_detect;
+		}
+	}
+
+	/* disable all sinks */
+	rc = regmap_write(wled->regmap,
+			  wled->sink_addr + WLED4_SINK_REG_CURR_SINK, 0);
+	if (rc < 0) {
+		pr_err("Failed to disable all sinks rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	/* iterate through the strings one by one */
+	for (i = 0; i < wled->cfg.num_strings; i++) {
+		sink_test = BIT((WLED4_SINK_REG_CURR_SINK_SHFT + i));
+
+		/* Enable feedback control */
+		rc = regmap_write(wled->regmap, wled->ctrl_addr +
+				  WLED3_CTRL_REG_FEEDBACK_CONTROL, i + 1);
+		if (rc < 0) {
+			pr_err("Failed to enable feedback for SINK %d rc = %d\n",
+			       i + 1, rc);
+			goto failed_detect;
+		}
+
+		/* enable the sink */
+		rc = regmap_write(wled->regmap, wled->sink_addr +
+				  WLED4_SINK_REG_CURR_SINK, sink_test);
+		if (rc < 0) {
+			pr_err("Failed to configure SINK %d rc=%d\n", i + 1,
+			       rc);
+			goto failed_detect;
+		}
+
+		/* Enable the module */
+		rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
+					WLED3_CTRL_REG_MOD_EN,
+					WLED3_CTRL_REG_MOD_EN_MASK,
+					WLED3_CTRL_REG_MOD_EN_MASK);
+		if (rc < 0) {
+			pr_err("Failed to enable WLED module rc=%d\n", rc);
+			goto failed_detect;
+		}
+
+		usleep_range(WLED_SOFT_START_DLY_US,
+			     WLED_SOFT_START_DLY_US + 1000);
+
+		rc = regmap_read(wled->regmap, wled->ctrl_addr +
+				 WLED3_CTRL_REG_INT_RT_STS, &int_sts);
+		if (rc < 0) {
+			pr_err("Error in reading WLED3_CTRL_INT_RT_STS rc=%d\n",
+			       rc);
+			goto failed_detect;
+		}
+
+		if (int_sts & WLED3_CTRL_REG_OVP_FAULT_STATUS)
+			pr_debug("WLED OVP fault detected with SINK %d\n",
+				 i + 1);
+		else
+			sink_valid |= sink_test;
+
+		/* Disable the module */
+		rc = regmap_update_bits(wled->regmap,
+					wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN,
+					WLED3_CTRL_REG_MOD_EN_MASK, 0);
+		if (rc < 0) {
+			pr_err("Failed to disable WLED module rc=%d\n", rc);
+			goto failed_detect;
+		}
+	}
+
+	if (sink_valid == sink_config) {
+		pr_debug("WLED auto-detection complete, default sink-config=%x OK!\n",
+			 sink_config);
+	} else {
+		pr_warn("Invalid WLED default sink config=%x changing it to=%x\n",
+			sink_config, sink_valid);
+		sink_config = sink_valid;
+	}
+
+	if (!sink_config) {
+		pr_err("No valid WLED sinks found\n");
+		wled->force_mod_disable = true;
+		goto failed_detect;
+	}
+
+	/* write the new sink configuration */
+	rc = regmap_write(wled->regmap,
+			  wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
+			  sink_config);
+	if (rc < 0) {
+		pr_err("Failed to reconfigure the default sink rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	/* Enable valid sinks */
+	for (i = 0; i < wled->cfg.num_strings; i++) {
+		if (wled->cfg.cabc) {
+			rc = regmap_update_bits(wled->regmap, wled->sink_addr +
+						WLED4_SINK_REG_STR_CABC(i),
+						WLED4_SINK_REG_STR_CABC_MASK,
+						WLED4_SINK_REG_STR_CABC_MASK);
+			if (rc < 0)
+				goto failed_detect;
+		}
+
+		if (sink_config & BIT(WLED4_SINK_REG_CURR_SINK_SHFT + i))
+			val = WLED4_SINK_REG_STR_MOD_MASK;
+		else
+			val = 0x0; /* disable modulator_en for unused sink */
+
+		rc = regmap_write(wled->regmap, wled->sink_addr +
+				  WLED4_SINK_REG_STR_MOD_EN(i), val);
+		if (rc < 0) {
+			pr_err("Failed to configure MODULATOR_EN rc=%d\n", rc);
+			goto failed_detect;
+		}
+	}
+
+	/* restore the feedback setting */
+	rc = regmap_write(wled->regmap,
+			  wled->ctrl_addr + WLED3_CTRL_REG_FEEDBACK_CONTROL, 0);
+	if (rc < 0) {
+		pr_err("Failed to restore feedback setting rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	/* restore  brightness */
+	rc = wled4_set_brightness(wled, wled->brightness);
+	if (rc < 0) {
+		pr_err("Failed to set brightness after auto detection rc=%d\n",
+		       rc);
+		goto failed_detect;
+	}
+
+	rc = regmap_update_bits(wled->regmap,
+				wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN,
+				WLED3_CTRL_REG_MOD_EN_MASK,
+				WLED3_CTRL_REG_MOD_EN_MASK);
+	if (rc < 0) {
+		pr_err("Failed to enable WLED module rc=%d\n", rc);
+		goto failed_detect;
+	}
+
+	wled->auto_detection_done = true;
+
+failed_detect:
+	return rc;
+}
+
+#define WLED_AUTO_DETECT_OVP_COUNT		5
+#define WLED_AUTO_DETECT_CNT_DLY_US		HZ /* 1 second */
+static bool wled_auto_detection_required(struct wled *wled)
+{
+	s64 elapsed_time_us;
+
+	if (*wled->version == WLED_PM8941)
+		return false;
+	/*
+	 * Check if the OVP fault was an occasional one
+	 * or if it's firing continuously, the latter qualifies
+	 * for an auto-detection check.
+	 */
+	if (!wled->auto_detection_ovp_count) {
+		wled->start_ovp_fault_time = ktime_get();
+		wled->auto_detection_ovp_count++;
+	} else {
+		elapsed_time_us = ktime_us_delta(ktime_get(),
+						 wled->start_ovp_fault_time);
+		if (elapsed_time_us > WLED_AUTO_DETECT_CNT_DLY_US)
+			wled->auto_detection_ovp_count = 0;
+		else
+			wled->auto_detection_ovp_count++;
+
+		if (wled->auto_detection_ovp_count >=
+				WLED_AUTO_DETECT_OVP_COUNT) {
+			wled->auto_detection_ovp_count = 0;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static int wled_auto_detection_at_init(struct wled *wled)
+{
+	int rc;
+	u32 fault_status = 0, rt_status = 0;
+
+	if (*wled->version == WLED_PM8941)
+		return 0;
+
+	if (!wled->cfg.auto_detection_enabled)
+		return 0;
+
+	rc = regmap_read(wled->regmap,
+			 wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS,
+			 &rt_status);
+	if (rc < 0) {
+		pr_err("Failed to read RT status rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = regmap_read(wled->regmap,
+			 wled->ctrl_addr + WLED3_CTRL_REG_FAULT_STATUS,
+			 &fault_status);
+	if (rc < 0) {
+		pr_err("Failed to read fault status rc=%d\n", rc);
+		return rc;
+	}
+
+	if ((rt_status & WLED3_CTRL_REG_OVP_FAULT_STATUS) ||
+	    (fault_status & WLED3_CTRL_REG_OVP_FAULT_BIT)) {
+		mutex_lock(&wled->lock);
+		rc = wled_auto_string_detection(wled);
+		if (!rc)
+			wled->auto_detection_done = true;
+		mutex_unlock(&wled->lock);
+	}
+
+	return rc;
+}
+
+static void handle_ovp_fault(struct wled *wled)
+{
+	if (!wled->cfg.auto_detection_enabled)
+		return;
+
+	mutex_lock(&wled->lock);
+	if (wled->ovp_irq > 0 && !wled->ovp_irq_disabled) {
+		disable_irq_nosync(wled->ovp_irq);
+		wled->ovp_irq_disabled = true;
+	}
+
+	if (wled_auto_detection_required(wled))
+		wled_auto_string_detection(wled);
+
+	if (wled->ovp_irq > 0 && wled->ovp_irq_disabled) {
+		enable_irq(wled->ovp_irq);
+		wled->ovp_irq_disabled = false;
+	}
+	mutex_unlock(&wled->lock);
+}
+
 static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
 {
 	struct wled *wled = _wled;
@@ -413,6 +706,9 @@ static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled)
 		dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x fault_sts= %x\n",
 			int_sts, fault_sts);
 
+	if (fault_sts & WLED3_CTRL_REG_OVP_FAULT_BIT)
+		handle_ovp_fault(wled);
+
 	return IRQ_HANDLED;
 }
 
@@ -575,6 +871,10 @@ static int wled4_setup(struct wled *wled)
 		return rc;
 	}
 
+	rc = wled_auto_detection_at_init(wled);
+	if (rc < 0)
+		return rc;
+
 	if (wled->cfg.external_pfet) {
 		/* Unlock the secure register access */
 		rc = regmap_write(wled->regmap, wled->ctrl_addr +
@@ -602,6 +902,7 @@ static int wled4_setup(struct wled *wled)
 	.enabled_strings = 0xf,
 	.cabc = false,
 	.external_pfet = true,
+	.auto_detection_enabled = false,
 };
 
 static const u32 wled3_boost_i_limit_values[] = {
@@ -785,6 +1086,7 @@ static int wled_configure(struct wled *wled)
 		{ "qcom,ext-gen", &cfg->ext_gen, },
 		{ "qcom,cabc", &cfg->cabc, },
 		{ "qcom,external-pfet", &cfg->external_pfet, },
+		{ "qcom,auto-string-detection", &cfg->auto_detection_enabled, },
 	};
 
 	prop_addr = of_get_address(dev->of_node, 0, NULL, NULL);
-- 
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