[alsa-devel] [PATCH] ASoC: twl6040: Support for DT
Enable Device Tree based loading of the codec driver.
Example of dts section to load the twl6040-codec driver: twl6040: twl6040@4b { ... twl6040_codec: twl6040@0 { compatible = "ti,twl6040-codec"; interrupts = <1>; }; };
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com --- .../devicetree/bindings/sound/twl6040.txt | 26 ++++++++++++++++++++ sound/soc/codecs/twl6040.c | 8 ++++++ 2 files changed, 34 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/sound/twl6040.txt
diff --git a/Documentation/devicetree/bindings/sound/twl6040.txt b/Documentation/devicetree/bindings/sound/twl6040.txt new file mode 100644 index 0000000..1f3dd70 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/twl6040.txt @@ -0,0 +1,26 @@ +ASoC codec driver for the twl6040 family + +The ASoC codec driver is a child of the twl6040 MFD dirver. +Documentation/devicetree/bindings/mfd/twl6040.txt + +Required properties: +- compatible : Must be "ti,twl6040-codec"; +- interrupts: 1, Jack plug detection IRQ + +Example: +/* + * 8-channel high quality low-power audio codec + * http://www.ti.com/lit/ds/symlink/twl6040.pdf + */ +twl6040: twl6040@4b { + ... + twl6040_codec: twl6040@0 { + compatible = "ti,twl6040-codec"; + interrupts = <1>; + }; +}; + +sound { /* ASoC machine dirver */ + ... + dai-link,codec = <&twl6040_codec>; +}; diff --git a/sound/soc/codecs/twl6040.c b/sound/soc/codecs/twl6040.c index 0747260..85c6e0c 100644 --- a/sound/soc/codecs/twl6040.c +++ b/sound/soc/codecs/twl6040.c @@ -25,6 +25,7 @@ #include <linux/delay.h> #include <linux/pm.h> #include <linux/platform_device.h> +#include <linux/of_device.h> #include <linux/slab.h> #include <linux/mfd/twl6040.h>
@@ -1229,10 +1230,17 @@ static int __devexit twl6040_codec_remove(struct platform_device *pdev) return 0; }
+static const struct of_device_id twl6040_codec_of_match[] = { + {.compatible = "ti,twl6040-codec", }, + { }, +}; +MODULE_DEVICE_TABLE(of, twl6040_codec_of_match); + static struct platform_driver twl6040_codec_driver = { .driver = { .name = "twl6040-codec", .owner = THIS_MODULE, + .of_match_table = twl6040_codec_of_match, }, .probe = twl6040_codec_probe, .remove = __devexit_p(twl6040_codec_remove),
On Tue, May 08, 2012 at 02:52:25PM +0300, Peter Ujfalusi wrote:
+static const struct of_device_id twl6040_codec_of_match[] = {
- {.compatible = "ti,twl6040-codec", },
- { },
+}; +MODULE_DEVICE_TABLE(of, twl6040_codec_of_match);
Why are we loading MFD components using device tree? It seems like we're doing something very wrong if we need people to explicitly write this stuff out in the device tree, the whole MFD thing is purely a Linux implementation detail, as is the way the interrupt controller has been structured. I'd really not expect to see a specific node like this, especially not one that does nothing but device registration.
On 05/08/2012 03:26 PM, Mark Brown wrote:
On Tue, May 08, 2012 at 02:52:25PM +0300, Peter Ujfalusi wrote:
+static const struct of_device_id twl6040_codec_of_match[] = {
- {.compatible = "ti,twl6040-codec", },
- { },
+}; +MODULE_DEVICE_TABLE(of, twl6040_codec_of_match);
Why are we loading MFD components using device tree? It seems like we're doing something very wrong if we need people to explicitly write this stuff out in the device tree, the whole MFD thing is purely a Linux implementation detail, as is the way the interrupt controller has been structured. I'd really not expect to see a specific node like this, especially not one that does nothing but device registration.
I have based the twl6040 DT structure on the already existing twl4030, twl6030 MFD parts. After all the twl6040 provides audio, vibra and it will also provide GPO (it has general purpose outputs - the driver is under development for this function). Also without a DT entry I will not have a way to use phandle to connect the codec in the machine driver. I would expect other operating systems should be able to sue this structure since in every environment there must be a way to handle MFD devices.
On Tue, May 08, 2012 at 03:42:41PM +0300, Peter Ujfalusi wrote:
On 05/08/2012 03:26 PM, Mark Brown wrote:
Why are we loading MFD components using device tree? It seems like we're doing something very wrong if we need people to explicitly write
I have based the twl6040 DT structure on the already existing twl4030, twl6030 MFD parts.
This really isn't relevant to the issue...
Also without a DT entry I will not have a way to use phandle to connect the codec in the machine driver.
Of course you do! There's going to be a device tree entry for the chip, things can point at this perfectly happily.
I would expect other operating systems should be able to sue this structure since in every environment there must be a way to handle MFD devices.
A lot of things would just handle them by providing a single device driver which covers the entire chip. Things like the split between the vibra and CODEC drivers definitely vary between systems.
Hi Mark,
On 05/08/2012 04:41 PM, Mark Brown wrote:
On Tue, May 08, 2012 at 03:42:41PM +0300, Peter Ujfalusi wrote:
On 05/08/2012 03:26 PM, Mark Brown wrote:
Why are we loading MFD components using device tree? It seems like we're doing something very wrong if we need people to explicitly write
I have based the twl6040 DT structure on the already existing twl4030, twl6030 MFD parts.
This really isn't relevant to the issue...
I thought it was...
Also without a DT entry I will not have a way to use phandle to connect the codec in the machine driver.
Of course you do! There's going to be a device tree entry for the chip, things can point at this perfectly happily.
That's true but what can I do with that in the ASoC machine driver? The chip driver is _not_ the codec driver. I can craft the pdata for the MFD child devices out from the DT information but then the child devices will have no dev.of_node since they were not probed via OF. So I would have not phandle for the codec to be used to define the dai-link connection within the sound dts section.
Am I missing something here?
On Wed, May 09, 2012 at 03:01:23PM +0300, Peter Ujfalusi wrote:
On 05/08/2012 04:41 PM, Mark Brown wrote:
On Tue, May 08, 2012 at 03:42:41PM +0300, Peter Ujfalusi wrote:
Also without a DT entry I will not have a way to use phandle to connect the codec in the machine driver.
Of course you do! There's going to be a device tree entry for the chip, things can point at this perfectly happily.
That's true but what can I do with that in the ASoC machine driver? The chip driver is _not_ the codec driver.
This really doesn't seem like it should be at all hard to resolve...
I can craft the pdata for the MFD child devices out from the DT information but then the child devices will have no dev.of_node since they were not probed via OF. So I would have not phandle for the codec to be used to define the dai-link connection within the sound dts section.
Am I missing something here?
Clearly. This is all very circular. Obviously if you're intent on using a phandle specific to the MFD child then you need to have that in the device tree but this is because you're making the child devices externally visible... Clearly if we're not going to use the MFD subdevices in the DT then the links ought to reference the chip.
Hi Mark,
On 05/09/2012 04:35 PM, Mark Brown wrote:
That's true but what can I do with that in the ASoC machine driver? The chip driver is _not_ the codec driver.
This really doesn't seem like it should be at all hard to resolve...
By not using any phandle for the codec in the dts file. The phandle for the chip (MFD driver) is as useful as any other phandle for me to parse things in the ASoC machine driver.
I can craft the pdata for the MFD child devices out from the DT information but then the child devices will have no dev.of_node since they were not probed via OF. So I would have not phandle for the codec to be used to define the dai-link connection within the sound dts section.
Am I missing something here?
Clearly. This is all very circular. Obviously if you're intent on using a phandle specific to the MFD child then you need to have that in the device tree but this is because you're making the child devices externally visible... Clearly if we're not going to use the MFD subdevices in the DT then the links ought to reference the chip.
This boils down to this after all: how to handle an MFD device in DT? Clearly this is not really defined.
I suppose I can go with something like this in the dts for twl6040:
twl6040: twl6040@4b { compatible = "ti,twl6040"; reg = <0x4b>; interrupts = <0 119 4>; /* IRQ_SYS_2N cascaded to gic */ interrupt-parent = <&gic>; twl6040,audpwron_gpio = <&gpio4 31 0>; /* gpio 127 */ enable-active-high;
interrupt-controller; #interrupt-cells = <1>;
vio-supply = <&v1v8>; v2v1-supply = <&v2v1>;
vibra { vddvibl-supply = <&vbat>; vddvibr-supply = <&vbat>; vibldrv_res = <8>; vibrdrv_res = <3>; viblmotor_res = <10>; vibrmotor_res = <10>; }; };
So we probe the MFD driver via DT. We construct the mfd children struct for ASoC codec (always, since the main function of twl6040 is to provide audio), or I can have a property like twl6040,audio_enabled to explicitly enable the audio functionality. We created the vibra device only if the vibra section exist. We register use mfd_add_devices() in DT probed mode as well.
The vibra driver can get it's configuration via pdev->dev.parent->of_node (from the MFD OF node).
As for the machine driver:
sound { compatible = "ti,abe-twl6040"; abe-twl6040,model = "SDP4430";
abe-twl6040,jack_detection = <1>; abe-twl6040,mclk_freq = <38400000>;
codec,dmic = <&dmic_codec>;
dai,mcpdm = <&mcpdm>; dai,dmic = <&dmic>;
/* Audio routing */ abe-twl6040,audio-routing = "Headset Stereophone", "HSOL", "Headset Stereophone", "HSOR", "Earphone Spk", "EP", "Ext Spk", "HFL", "Ext Spk", "HFR", "Line Out", "AUXL", "Line Out", "AUXR", "Vibrator", "VIBRAL", "Vibrator", "VIBRAR", "HSMIC", "Headset Mic", "Headset Mic", "Headset Mic Bias", "MAINMIC", "Main Handset Mic", "Main Handset Mic", "Main Mic Bias", "SUBMIC", "Sub Handset Mic", "Sub Handset Mic", "Main Mic Bias", "AFML", "Line In", "AFMR", "Line In", "DMic", "Digital Mic", "Digital Mic", "Digital Mic1 Bias"; };
In the driver I remove the mcpdm dai names and and the phandle for it instead. Same for the dmic dai and for the dmic codec. Since the twl6040 ASoC codec does not have phandle (not loaded via DT) I do not need to touch it, I can leave the codec_name as it was. The number of DAI links can be checked if we have for example the codec,dmic property set. If it is set we have 2 links, if it is not set we have one (twl6040 <-> mcpdm).
Mark: is this what you were suggesting?
On Thu, May 10, 2012 at 03:55:53PM +0300, Peter Ujfalusi wrote:
On 05/09/2012 04:35 PM, Mark Brown wrote:
This really doesn't seem like it should be at all hard to resolve...
By not using any phandle for the codec in the dts file.
Why even do that? Just refer to the MFD. It'd look a lot more idiomatic.
Mark: is this what you were suggesting?
Removing the DMIC stuff until we've figured out how we handle DMICs, AMICs and jacks seems sensible yes - I think what you've got at the minute is likely to be the way we end up going but it's better to be sure.
+ DT list
Hi Mark,
On 5/9/2012 3:35 PM, Mark Brown wrote:
On Wed, May 09, 2012 at 03:01:23PM +0300, Peter Ujfalusi wrote:
On 05/08/2012 04:41 PM, Mark Brown wrote:
On Tue, May 08, 2012 at 03:42:41PM +0300, Peter Ujfalusi wrote:
Also without a DT entry I will not have a way to use phandle to connect the codec in the machine driver.
Of course you do! There's going to be a device tree entry for the chip, things can point at this perfectly happily.
That's true but what can I do with that in the ASoC machine driver? The chip driver is _not_ the codec driver.
This really doesn't seem like it should be at all hard to resolve...
I can craft the pdata for the MFD child devices out from the DT information but then the child devices will have no dev.of_node since they were not probed via OF. So I would have not phandle for the codec to be used to define the dai-link connection within the sound dts section.
Am I missing something here?
Clearly. This is all very circular. Obviously if you're intent on using a phandle specific to the MFD child then you need to have that in the device tree but this is because you're making the child devices externally visible... Clearly if we're not going to use the MFD subdevices in the DT then the links ought to reference the chip.
I'm not sure to understand you concern here.
Describing sub nodes, especially for big SoC is pretty useful. It is as useful as doing that for board that are sharing similar components. It will allow to define several Audio / PMIC variants without having to rewrite a driver potentially.
DT is about HW description. You can go to whatever level you'd like as soon as it is relevant for the drivers.
In this is case it is relevant since the sub-devices will have driver to be bound to the device nodes.
Both Vibra and Codec IPs can be located elsewhere, so by exposing that inside the DT, you will increase the level of HW details and thus make the re-use of these sub-IPs easier.
The twl6040 is just a container. These IPs can be inside a PCI chip, or inside OMAP or whatever, but they do need a node to represent them. In this case the container is irrelevant, only the children matter.
Moreover, the fact the Linux implementation uses MFD to represent that is irrelevant for the DT description. We should be able to use whatever SW representation for this type of HW.
DT was useful to get rid of static board definition. DT can be useful as well to get rid of the static cell definition inside a MFD. This is exactly the same problem at different HW level.
Regards, Benoit
On Fri, May 11, 2012 at 01:02:26PM +0200, Cousson, Benoit wrote:
On 5/9/2012 3:35 PM, Mark Brown wrote:
Clearly. This is all very circular. Obviously if you're intent on using a phandle specific to the MFD child then you need to have that in the device tree but this is because you're making the child devices externally visible... Clearly if we're not going to use the MFD subdevices in the DT then the links ought to reference the chip.
I'm not sure to understand you concern here.
Describing sub nodes, especially for big SoC is pretty useful. It is as useful as doing that for board that are sharing similar components.
The concern here is that the device tree you're writing here is clearly just a direct translation of the particular stuff Linux happens to use internally into device tree; this is similar to the thing with using hwmod in the device tree representation and omitting basic stuff like the register ranges.
It will allow to define several Audio / PMIC variants without having to rewrite a driver potentially.
This binding doesn't do anything to move towards that goal given that the only information it includes about the contents of the chip is the name. Writing the name out in separate CODEC and vibra nodes really isn't going to accomplish much to promote reuse that can't trivially be achieved by parsing the name in the MFD driver.
If the binding were doing things like describing the internals of the device in a way that meant the driver didn't need to know that this was a twl6040 in particular this sort of thinking is useful but the binding we have here just isn't doing that at all.
Both Vibra and Codec IPs can be located elsewhere, so by exposing that inside the DT, you will increase the level of HW details and thus make the re-use of these sub-IPs easier.
Especially for the CODEC it's not really an IP in itself, it's an assembly of large numbers of other IPs - digital audio interfaces, analogue amps and whatnot. Like I say if the device tree described this assembly it'd be different but it's really not doing that.
Moreover, the fact the Linux implementation uses MFD to represent that is irrelevant for the DT description. We should be able to use whatever SW representation for this type of HW.
This is precisely my point, what we're being presented with here is a device tree description of the particular way that Linux wants to understand this stuff rather than something that lets us learn about the chip internals.
On 5/11/2012 3:08 PM, Mark Brown wrote:
On Fri, May 11, 2012 at 01:02:26PM +0200, Cousson, Benoit wrote:
On 5/9/2012 3:35 PM, Mark Brown wrote:
Clearly. This is all very circular. Obviously if you're intent on using a phandle specific to the MFD child then you need to have that in the device tree but this is because you're making the child devices externally visible... Clearly if we're not going to use the MFD subdevices in the DT then the links ought to reference the chip.
I'm not sure to understand you concern here.
Describing sub nodes, especially for big SoC is pretty useful. It is as useful as doing that for board that are sharing similar components.
The concern here is that the device tree you're writing here is clearly just a direct translation of the particular stuff Linux happens to use internally into device tree; this is similar to the thing with using hwmod in the device tree representation and omitting basic stuff like the register ranges.
It will allow to define several Audio / PMIC variants without having to rewrite a driver potentially.
This binding doesn't do anything to move towards that goal given that the only information it includes about the contents of the chip is the name.
But it does not have to expose everything. And what will be your definition of everything in that case?
Writing the name out in separate CODEC and vibra nodes really isn't going to accomplish much to promote reuse that can't trivially be achieved by parsing the name in the MFD driver.
Maybe, but... so what? This is not because you can do it with MFD that you cannot make it more flexible with DT. Preferring to hard code that in MFD is similar to keeping all the static C board files we are all trying to remove. It is possible, sure, but there are now better way to describe HW modules than hard-coding that in a C file.
Moreover, there is not an unique way to describe the HW. So for sure we will cheat a little bit and make some assumption about what the SW will really use. But otherwise you will end up putting the full RTL inside the DT node. It is very similar to the discussion we had for the clock tree. For sure we can describe the full clock tree in DT, but that's huge and useless. So we are taking some assumption and expose only the ones that have to be exposed because dependent of the board or needed by the devices.
If the binding were doing things like describing the internals of the device in a way that meant the driver didn't need to know that this was a twl6040 in particular this sort of thinking is useful but the binding we have here just isn't doing that at all.
Both Vibra and Codec IPs can be located elsewhere, so by exposing that inside the DT, you will increase the level of HW details and thus make the re-use of these sub-IPs easier.
Especially for the CODEC it's not really an IP in itself, it's an assembly of large numbers of other IPs - digital audio interfaces, analogue amps and whatnot. Like I say if the device tree described this assembly it'd be different but it's really not doing that.
Moreover, the fact the Linux implementation uses MFD to represent that is irrelevant for the DT description. We should be able to use whatever SW representation for this type of HW.
This is precisely my point, what we're being presented with here is a device tree description of the particular way that Linux wants to understand this stuff rather than something that lets us learn about the chip internals.
As I said before; there is not a single way to describe that kind of HW. But still this description is perfectly valid for the HW point of view. It just does not represent all the details inside the CODEC. But the way DT is done, nothing can prevent someone else to add further details below that node assuming there will be some SW to use that at some point.
It is up to the driver owner to assess the level of information he'd like to expose to DT based on the number of chip variants that already exist.
So far, MFD was the only way to describe some HW hierarchy in a SoC that only have platform_device. Now, DT can do that as well without hard coding some sub device information inside a driver, thus allowing you to change that sub-device without changing the driver.
Both formats are valid. It is just a matter of flexibility / personal choice / mood of the day.
The important point is that this is not a black or white kind of decision, we can be in the grey area and use a little bit of both approach.
Thanks, Benoit
On Fri, May 11, 2012 at 05:44:19PM +0200, Cousson, Benoit wrote:
On 5/11/2012 3:08 PM, Mark Brown wrote:
This binding doesn't do anything to move towards that goal given that the only information it includes about the contents of the chip is the name.
But it does not have to expose everything. And what will be your definition of everything in that case?
A useful binding that abstracted things sufficiently to allow multiple devices would be one which contained some information about the contents of the chip.
Writing the name out in separate CODEC and vibra nodes really isn't going to accomplish much to promote reuse that can't trivially be achieved by parsing the name in the MFD driver.
Maybe, but... so what? This is not because you can do it with MFD that you cannot make it more flexible with DT.
The issue is the tastefulness. Just looking at the binding it's immediately clear that the only thing that the extra levels of indirection are adding is the removal of the mfd_add_cells() call from the MFD driver which isn't particularly helping anything and is basically Linux specific.
Preferring to hard code that in MFD is similar to keeping all the static C board files we are all trying to remove. It is possible, sure, but there are now better way to describe HW modules than hard-coding that in a C file.
Sure, but this binding doesn't do anything like that. If it said things like "there's a PDM speaker driver with register map X at address Y" then you'd have a block you could easily pick up and reuse when defining another device but it doesn't do that at all.
Moreover, there is not an unique way to describe the HW. So for sure we will cheat a little bit and make some assumption about what the SW will really use. But otherwise you will end up putting the full RTL inside the DT node.
This isn't a "cheat a little bit" type thing - it's really not talking about blocks that are likely to reappear elsewhere in exactly the same form on a device that's different enough that you'd be able to add some useful reuse via the device tree.
With CODECs the IP blocks you see are generally things like audio interfaces, mixers, PLLs, amplifiers and so on. New devices that are meaningfully different to software will generally be some new combination of that sort of stuff rather than a straight clone of the chip top level which is what this binding is talking about.
It is very similar to the discussion we had for the clock tree. For sure we can describe the full clock tree in DT, but that's huge and useless. So we are taking some assumption and expose only the ones that have to be exposed because dependent of the board or needed by the devices.
The difference I'm seeing here is that the split in the device tree here is at such that it's the equivalent of having a single device tree node for the entire clock tree of a given OMAP model - it's just completely redundant, it's not adding any additional information beyond the top level information about which chip this is.
It is up to the driver owner to assess the level of information he'd like to expose to DT based on the number of chip variants that already exist.
This code handles exactly one chip and looking at it it's *extremely* hard to see it as a useful abstraction for multiple chips. There's also the fact that with things like this where the chip has to be hooked up to other pieces of the system it makes much more of a difference than it might otherwise since it's much more externally visible. In this particular case for example we might want to split the clocking out differently as the generic clock API comes along, and there's extcon too. All of which should be entirely Linux internal things.
Both formats are valid. It is just a matter of flexibility / personal choice / mood of the day.
The important point is that this is not a black or white kind of decision, we can be in the grey area and use a little bit of both approach.
If I could see how this would allow reuse I'd probably agree with you but I really can't - it's immediately obvious looking at what's there that all that's happening is that a bit of the Linux internals that's not particularly great as a generic abstraction dropped straight into the device tree.
Plus there's the fact that from both a device tree and a code point of view it's utterly trivial to not land ourselves with this in the device tree, it's just registering two devices and using a different of_node for reading properties in code and removing a layer of indentation in the DT.
On 05/11/2012 11:34 PM, Mark Brown wrote:
The issue is the tastefulness. Just looking at the binding it's immediately clear that the only thing that the extra levels of indirection are adding is the removal of the mfd_add_cells() call from the MFD driver which isn't particularly helping anything and is basically Linux specific.
It is not really a coincident that we have the drivers structured in a way they are at the moment (with or without MFD). We have several functionality provided by this chip (twl6040). In one chip it provides audio (twl6040-codec), vibra (twl6040-vibra) and we are going to have few more additions as well (GPO, clock driver to provide the McPDM functional clock).
We might see more integrated solution in a future which would combine the current pmic and the audio in a single chip. If this happens we can just use the dts sections describing the functionalities of the twl6040 appended to this - theoretical - chip. The child (or drivers for the functionality) only needs small update for compatible_of, and new chip access wrapper. In this case the core chip driver (twl6040 MFD) will no longer exist/make sense since the functionality provided by the twl6040 chip has been merged together with the PMIC.
You might be right that the resulting dts section for the chip is just represents the current MD stack, but if I want to prepare for the future this is the way I think is the best for us.
On Mon, May 14, 2012 at 02:38:20PM +0300, Peter Ujfalusi wrote:
The child (or drivers for the functionality) only needs small update for compatible_of, and new chip access wrapper.
At the very least anything that's using interrupts through the device core will also need to know how those have been wired out into the chip top level, and of course if anything happened to move about in the register map or there are any changes in available functionality (which would be unsurprising, perhaps an additional line output or something for example) those will also need to be dealt with.
Besides, if that's all the function drivers need to look at they can just look at their parent node instead of looking at the child node, problem sorted.
You might be right that the resulting dts section for the chip is just represents the current MD stack, but if I want to prepare for the future this is the way I think is the best for us.
Again, if I could see how this supported non-trivial reuse I'd be right with you but I'm just not seeing how this would allow reuse on another chip without rework of all existing device trees or what it hides about the chip top level. The code changes to drop the child nodes from the device tree should be trivial. This in itself seems to me like a clear sign that the abstraction in the device tree isn't actually providing useful generalisation of the chip.
I'm just not seeing anything in the device tree that abstracts the chip top level from the function drivers; if there were then it'd be very much easier to see a general use for this.
Hi Mark,
On 05/14/2012 03:11 PM, Mark Brown wrote:
I'm just not seeing anything in the device tree that abstracts the chip top level from the function drivers; if there were then it'd be very much easier to see a general use for this.
While we are discussing on how to handle the twl6040 MFD deive via DT and to whether load the child drivers via DT or to load them via mfd_add_devices() I came up with this dts entry for the later case (mfd_add_devices mode):
&i2c1 { twl6040: twl@4b { compatible = "ti,twl6040"; reg = <0x4b>;
interrupts = <0 119 4>; interrupt-parent = <&gic>; twl6040,audpwron-gpio = <&gpio4 31 0>;
vio-supply = <&v1v8>; v2v1-supply = <&v2v1>; enable-active-high;
/* regulators for vibra motor */ vddvibl-supply = <&vbat>; vddvibr-supply = <&vbat>;
vibra { /* Vibra driver, motor resistance parameters */ ti,vibldrv-res = <8>; ti,vibrdrv-res = <3>; ti,viblmotor-res = <10>; ti,vibrmotor-res = <10>; }; }; };
With this mode: No need to tell that twl6040 is acts as interrupt controller since the interrupts it is handling is only for internal functions dispatched via a single irq line toward the CPU.
The audio (ASoC codec) child is always enabled since it is the main function of the twl6040.
The tricky part is the vibra: it needs two regulators (to provide power to the motors). Since the regulators can only be connected to the device described in dt, this is what I need to do: to get the vibra parameters (in the twl6040-vibra driver):
struct device_node *node = of_find_node_by_name( pdev->dev.parent->of_node, "vibra");
... of_property_read_u32(node, "ti,vibldrv-res", &info->vibldrv_res); ...
To get the regulators needed by the vibra driver when booted with DT:
info->supplies[0].supply = "vddvibl"; info->supplies[1].supply = "vddvibr"; if (!pdata) ret = regulator_bulk_get(pdev->dev.parent, ARRAY_SIZE(info->supplies), info->supplies); else ret = regulator_bulk_get(info->dev, ARRAY_SIZE(info->supplies), info->supplies);
I need to use the pdev->dev.parent to be able to get the needed regulators. Is this acceptable?
* Mark Brown broonie@opensource.wolfsonmicro.com [120511 06:12]:
On Fri, May 11, 2012 at 01:02:26PM +0200, Cousson, Benoit wrote:
Describing sub nodes, especially for big SoC is pretty useful. It is as useful as doing that for board that are sharing similar components.
The concern here is that the device tree you're writing here is clearly just a direct translation of the particular stuff Linux happens to use internally into device tree; this is similar to the thing with using hwmod in the device tree representation and omitting basic stuff like the register ranges.
I agree we should not omit the register ranges from DT. That is hardware specific information that other operating systems possibly need, and they don't have hwmod.
Regards,
Tony
On 05/14/2012 06:34 PM, Tony Lindgren wrote:
I agree we should not omit the register ranges from DT. That is hardware specific information that other operating systems possibly need, and they don't have hwmod.
I was considering to do that for the omap-mcpdm, omap-dmic. I think the reason I did not done it is that none of the other dt sections for OMAP devices have this information (most probably for a reason).
participants (4)
-
Cousson, Benoit -
Mark Brown -
Peter Ujfalusi -
Tony Lindgren