Jacek On 1/11/19 3:52 PM, Jacek Anaszewski wrote: > Dan, > > On 1/11/19 1:38 PM, Dan Murphy wrote: >> Jacek >> >> Sorry I missed some replies >> >> On 1/10/19 4:03 PM, Jacek Anaszewski wrote: >>> On 1/10/19 9:43 PM, Dan Murphy wrote: >>>> Jacek >>>> >>>> On 1/10/19 1:57 PM, Jacek Anaszewski wrote: >>>>> Dan, >>>>> >>>>> On 1/10/19 8:22 PM, Dan Murphy wrote: >>>>>> Jacek >>>>>> >>>>>> On 1/10/19 12:44 PM, Jacek Anaszewski wrote: >>>>>>> Hi Dan, >>>>>>> >>>>>>> On 1/9/19 10:31 PM, Dan Murphy wrote: >>>>>>>> Jacek >>>>>>>> >>>>>>>> On 1/9/19 3:28 PM, Jacek Anaszewski wrote: >>>>>>>>> On 1/9/19 10:12 PM, Dan Murphy wrote: >>>>>>>>>> On 1/9/19 2:12 PM, Jacek Anaszewski wrote: >>>>>>>>>>> Hi Dan, >>>>>>>>>>> >>>>>>>>>>> On 1/8/19 10:22 PM, Dan Murphy wrote: >>>>>>>>>>>> On 1/8/19 3:16 PM, Jacek Anaszewski wrote: >>>>>>>>>>>>> On 1/8/19 9:53 PM, Dan Murphy wrote: >>>>>>>>>>>>>> Jacek >>>>>>>>>>>>>> >>>>>>>>>>>>>> On 1/8/19 2:33 PM, Jacek Anaszewski wrote: >>>>>>>>>>>>>>> Dan, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> On 12/19/18 5:26 PM, Dan Murphy wrote: >>>>>>>>>>>>>>>> Introduce the bindings for the Texas Instruments LP5024 and the LP5018 >>>>>>>>>>>>>>>> RGB LED device driver. The LP5024/18 can control RGB LEDs individually >>>>>>>>>>>>>>>> or as part of a control bank group. These devices have the ability >>>>>>>>>>>>>>>> to adjust the mixing control for the RGB LEDs to obtain different colors >>>>>>>>>>>>>>>> independent of the overall brightness of the LED grouping. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Datasheet: >>>>>>>>>>>>>>>> http://www.ti.com/lit/ds/symlink/lp5024.pdf >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@xxxxxx> >>>>>>>>>>>>>>>> --- >>>>>>>>>>>>>>>> .../devicetree/bindings/leds/leds-lp5024.txt | 63 +++++++++++++++++++ >>>>>>>>>>>>>>>> 1 file changed, 63 insertions(+) >>>>>>>>>>>>>>>> create mode 100644 Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> diff --git a/Documentation/devicetree/bindings/leds/leds-lp5024.txt b/Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>>>>> index 000000000000..9567aa6f7813 >>>>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>>>> +++ b/Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>>>>>>>>>>>>> @@ -0,0 +1,63 @@ >>>>>>>>>>>>>>>> +* Texas Instruments - LP5024/18 RGB LED driver >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +The LM3692x is an ultra-compact, highly efficient, >>>>>>>>>>>>>>>> +white-LED driver designed for LCD display backlighting. >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +The main difference between the LP5024 and L5018 is the number of >>>>>>>>>>>>>>>> +RGB LEDs they support. The LP5024 supports twenty four strings while the >>>>>>>>>>>>>>>> +LP5018 supports eighteen strings. >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +Required properties: >>>>>>>>>>>>>>>> + - compatible: >>>>>>>>>>>>>>>> + "ti,lp5018" >>>>>>>>>>>>>>>> + "ti,lp5024" >>>>>>>>>>>>>>>> + - reg : I2C slave address >>>>>>>>>>>>>>>> + - #address-cells : 1 >>>>>>>>>>>>>>>> + - #size-cells : 0 >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +Optional properties: >>>>>>>>>>>>>>>> + - enable-gpios : gpio pin to enable/disable the device. >>>>>>>>>>>>>>>> + - vled-supply : LED supply >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +Required child properties: >>>>>>>>>>>>>>>> + - reg : Is the child node iteration. >>>>>>>>>>>>>>>> + - led-sources : LP5024 - 0 - 7 >>>>>>>>>>>>>>>> + LP5018 - 0 - 5 >>>>>>>>>>>>>>>> + Declares the LED string or strings that the child node >>>>>>>>>>>>>>>> + will control. If ti,control-bank is set then this >>>>>>>>>>>>>>>> + property will contain multiple LED IDs. >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +Optional child properties: >>>>>>>>>>>>>>>> + - label : see Documentation/devicetree/bindings/leds/common.txt >>>>>>>>>>>>>>>> + - linux,default-trigger : >>>>>>>>>>>>>>>> + see Documentation/devicetree/bindings/leds/common.txt >>>>>>>>>>>>>>>> + - ti,control-bank : Indicates that the LED strings declared in the >>>>>>>>>>>>>>>> + led-sources property are grouped within a control >>>>>>>>>>>>>>>> + bank for brightness and mixing control. >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +Example: >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> +led-controller@28 { >>>>>>>>>>>>>>>> + compatible = "ti,lp5024"; >>>>>>>>>>>>>>>> + reg = <0x28>; >>>>>>>>>>>>>>>> + #address-cells = <1>; >>>>>>>>>>>>>>>> + #size-cells = <0>; >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> + enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>; >>>>>>>>>>>>>>>> + vled-supply = <&vbatt>; >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> + led@0 { >>>>>>>>>>>>>>>> + reg = <0>; >>>>>>>>>>>>>>>> + led-sources = <1>; >>>>>>>>>>>>>>>> + }; >>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>> + led@1 { >>>>>>>>>>>>>>>> + reg = <1>; >>>>>>>>>>>>>>>> + led-sources = <0 6>; >>>>>>>>>>>>>>>> + ti,control-bank; >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Do you really need ti,control-bank? Doesn't led-sources array size >>>>>>>>>>>>>>> greater than 1 mean that the node describes control bank? >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> That will work too. >>>>>>>>>>>>> >>>>>>>>>>>>>>> Also, does it make sense to have only two LEDs in the bank? >>>>>>>>>>>>>> >>>>>>>>>>>>>> The array can populate all 7 LEDs in a single node. I only show 2 here as the example. >>>>>>>>>>>>>> See the description above of the led-sources >>>>>>>>>>>>> >>>>>>>>>>>>> OK, I confused RGB LED modules with banks. >>>>>>>>>>>>> >>>>>>>>>>>>> Shouldn't we allow for defining either strings or RGB LED >>>>>>>>>>>>> triplets somehow then? >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Well that is what this should be doing. If you define a single LED in LED sources then >>>>>>>>>>>> the triplet is controlled via the associated LEDx_brightness register. >>>>>>>>>>> >>>>>>>>>>> led-sources should map to iouts directly. >>>>>>>>>>> So, for RGB LED modules I would expect: >>>>>>>>>>> >>>>>>>>>>> LED0: led-sources = <0 1 2>; >>>>>>>>>>> LED1: led-sources = <3 4 5>; >>>>>>>>>>> LED2: led-sources = <6 7 8>; >>>>>>>>>>> and so on. >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> for banks: >>>>>>>>>>> >>>>>>>>>>> Bank A with iouts 0,3,6,9: led-sources<0 3 6 9>; >>>>>>>>>>> Bank B with iouts 2,4,10: led-sources<2 4 10>; >>>>>>>>>>> Bank C with iouts 5,8,11,14,17: led-sources<5 8 11 14 17>; >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Ok the led-sources would need to be different then this as I don't define the sources for banks. >>>>>>>>>> >>>>>>>>>> The led-sources for the banks and the individual groups will have different meanings within the same >>>>>>>>>> document. I was attempting to keep the led-sources mapped to the LEDx_brightness registers as opposed to >>>>>>>>>> the hardware outputs since the RGB LEDs are controlled and grouped by a single brightness register and if banked then >>>>>>>>>> it would be controlled by the bank brightness register. >>>>>>>>>> >>>>>>>>>> Describing these in the DT seems wrought with potential issues as the data sheet defines what outputs map to what bank and LED >>>>>>>>>> registers. >>>>>>>>> >>>>>>>>> Yes, that's why I mentioned the need for validation of led-sources. >>>>>>>>> But they have to be iouts. This property was introduced specifically >>>>>>>>> for such purposes. >>>>>>>>> >>>>>>>> >>>>>>>> Yes Pavel also mentioned that as well. >>>>>>>> >>>>>>>> I will look into validating the sources. But there will be no mapping of the sources to the output that is done >>>>>>>> in the hardware. This would just be a data sheet mapping since the outputs are not configurable. >>>>>>> >>>>>>> Hmm, isn't the mapping defined in the hardware via LED_CONFIG0 register? >>>>>>> I have an impression that it defines whether LED belongs to an RGB LED >>>>>>> module or to a bank. Basing on that I created my DT example above. >>>>>>> >>>>>> >>>>>> Yes so if you turn on the bank control for LED0 and LED1 then >>>>>> out 0, 3 are mapped to BANK A >>>>>> out 1, 4 are mapped to BANK B >>>>> >>>>> Just noticed that I made a mistake in my example, it should have been: >>>>> >>>>> Bank B with iouts 1,4,10: led-sources<1 4 10>; >>>>> >>>>>> out 2, 5 are mapped to BANK C >>>>> >>>>> Correct. >>>>> >>>>>> All done automatically in the hardware and the LED0_BRIGHTNESS and LED1_BRIGHTNESS registers have no affect on the brightness >>>>> >>>>> That's right. >>>>> >>>>>> If we grouped the LEDs into a bank the led-sources would look more like this >>>>>> led-sources = < 0 1 2 3 4 5 >; >>>>> >>>>> Why? This would be a mix of three banks. Like you listed above. >>>>> I'm still interpreting led-sources elements as iout identifiers. >>>>> >>>> >>>> I am as well but as I tried to explain that if you define OUT0 as bank controlled then OUT1 and OUT2 are also bank controlled >>>> within the hardware. We have no control of that. If BIT(0) and BIT(1) are set in the LED_CONFIG0 register then OUT0, 1, 2, 3, 4 and 5 are all bank controlled. >>> >>> There is naming conflict I noticed just now - LEDn_BANK_EN bits >>> in LED_CONFIG0 register enable RGB LED modules, and not BANKs (A,B,C). >>> >>>> These OUTPUTs will appear as a single RGB LED grouping. >>> >>> Single? W would rather expect that we get two RGB LED modules, whose >>> brightness will be controlled via LED0_BRIGHTNESS and LED1_BRIGHTNESS >>> registers respectively. >>> >>>>>> ti,control-bank; // But this can be omitted as led-sources is greater then 3 >>>>>> >>>>>> non-banked case would be >>>>>> led-sources = < 0 1 2 >; >>>>> >>>>> Agreed here. It would be LED0 RGB LED module. >>>>>> But the actual OUT numbers don't matter in the bank case unless we do the validation. There would need to be an algorithim >>>>>> that translates these output to the correct LEDx register and CONFIG0 bits. Basically if OUT0 is mapped to the bank then OUT1 and OUT2 >>>>>> are inherently mapped to the bank. >>>>> >>>>> To three separate banks, right? >>>>> OUT0 - bank A, OUT1 - bank B, OUT2 - bank C. >>>> >>>> Yes but there is no BANK output pin just like there is no dedicated LEDn output pin. The banks are grouped internally to the device >>>> so again if OUT0 and OUT3 are defined as banked then 1, 2, 4, and 5 are all mapped to the bank. 1 BANK brightness register and 3 bank >>>> color adjustment registers. >>> >>> Here as above, I would expect two separate banks - LED0 and LED1. >>> Moreover - not 3 color adjustment registers, but six - one per iout: >>> OUT0_COLOR to OUT5_COLOR. >>> >> >> When the LEDs are banked the banked LEDs are controlled by the bank registers not the LEDx registers >> so you should only see 3 color adjustments on the banked LEDs. >> >>>>>> They cannot be separated so the device theoretically treats the RGB group as a single LED. And >>>>>> when banked it treats the groups of RGBs that are defined as a single LED. >>>>>> >>>>>> This is why it was easier use the LEDx out as the virtual out as we only need to define the group number(s) that are controled by the >>>>>> LED file presented to the user space. >>>>> >>>>> I suspect there is logical clash here due to interpreting >>>>> led-sources elements as iouts in one case and LEDn modules >>>>> in the other case. >>>>> >>>> >>>> Yes. When the RGBs are banked you have to think of them as a single RGB LED cluster and not as separate RGB LED clusters. >>> >>> We have RGB LED modules (enabled with LEDn_Bank_EN bits) and three >>> banks (A,B,C), which are enabled by default, am I right? >> >> No. Independent LED modules are enabled by default. You have to explicitly enable the banks. >> >>> >>> Bank A iouts: 0, 3 ,6, 9, 12, 15 >>> Bank B iouts: 1, 4, 7, 10, 13, 16 >>> Bank C iouts: 2, 5, 8, 11, 14, 17 >>> >>> When RGB LED module is enabled (via LEDn_Bank_EN bit), >>> the BANK_{A.B,C}_COLOR and BANK_BRIGHTNESS registers >>> lose control over related IOUTs in favour of LEDn_BRIGHTNESS and >>> related OUTn_COLOR registers. Is it correct? >> >> No it is the opposite. When the bit is enabled LED banking is enabled and the BANK brightness and color registers over >> ride the LEDx color and brightness registers. >> >> Default is independent control of the RGB via the LEDx color and brightness registers. >> >>> >>>> As you know the brightness is controlled by the single BANK_BRIGHTNESS register. So identifying each output in the led-sources is >>>> misleading as the hardware does this all on the chip. This is why I just mapped each output to the Virtual LEDx module. >>> >>> Ekhm, I messed something here. >>> >>> So for this I would define a single LED class device. >>> Related DT node would not need led-sources at all, >>> but only ti,control-bank. The semantics would be: >>> controls all iouts not taken by RGB LED modules. >>> >> >> Hmm. I guess I will put that on hold until you read the responses. I am not sure that would work or >> that would be really clean. I still believe that mapping led-sources to the LEDx module number is the cleanest >> simplest solution since the driver cannot inter mix different outputs for enablement. > > I've read the doc again more carefully and hopefully I finally have > proper understanding. Let's check it. > > 1. On reset LED_CONFIG0 bits are zeroed, which means > LEDn module independent control mode. > 2. LEDn modules (i.e. IOUT triplets) are controlled independently, > with use of LEDn_BRIGHTNESS registers, and each IOUT color can > be adjusted using OUTn_CONTROL registers. > 3. LEDn_Bank_EN bits, when set to 1, assign given RGB LED module > to one global bank, controlled via BANK_BRIGHTNESS and BANK_n_COLOR > registers. > > Having that, I'd see led-sources definitions as follows > (led-sources element is IOUT identifier) > > 1. > > - LED0, LED1, LED2, LED3 modules controlled by separate > LED class devices > > led-sources = <0 1 2> // LED0 > led-sources = <3 4 5> // LED1 > led-sources = <6 7 8> // LED2 > led-sources = <9 10 11> // LED3 > > 2. > > - LED0 and LED3 modules assigned to the bank, and controlled > by one LED class device, > - LED1 and LED2 modules controlled by separate LED class devices > > led-sources = <0 1 2 9 10 11> // Bank with LED0 and LED3 > led-sources = <3 4 5> // LED1 > led-sources = <6 7 8> // LED2 > > > So now I see your point. It would be indeed easier > to switch to LEDn module identifiers for led-sources > elements. With that the definitions would look like > this: > > > 1. > > - LED0, LED1, LED2, LED3 modules controlled by separate > LED class devices > > led-sources = <0> // LED0 > led-sources = <1> // LED1 > led-sources = <2> // LED2 > led-sources = <3> // LED3 > > 2. > > - LED0 and LED3 modules assigned to the bank, and controlled > by one LED class device, > - LED1 and LED2 modules controlled by separate LED class devices > > led-sources = <0 3> // Bank with LED0 and LED3 > led-sources = <1> // LED1 > led-sources = <2> // LED2 > This is exactly how I submitted the code. > > But, I don't think use of led-sources is justified in > this case. I propose to introduce device specific properties: > > ti,led-module and ti,led-bank > > With that we would have: > > ti,led-bank = <0 3> // Bank with LED0 and LED3 modules > ti,led-module = <1> // LED1 > ti.led-module = <2> // LED2 > We are now aligned. I can change the led-sources to the TI specific if there are no further objections. In doing this I can eliminate the ti,control-bank property. > >>> I would also add Table 1 contents (Bank Number and LED Number >>> Assignment) to the DT bindings. >>> >> >> Should I add that to the DT binding or reference the data sheet table since this driver will support 4 different devices >> with varying number of outputs from 18-36. > > My first thought was to show full table, but four different > mappings would add too much noise. So the reference to the data > sheet should suffice. > OK One last question I am going to add the LP5036 and 30 which have the same technology but slightly different register maps. Should I rename the driver to LP5036.c as the 30, 24 and 18 would technically be subsets? Dan -- ------------------ Dan Murphy
