Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 1/2] dt-bindings: reset: Add document for Broadcom STB
 reset controller
To:     Rob Herring <robh@kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>
Cc:     p.zabel@pengutronix.de, linux-kernel@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Brian Norris <computersforpeace@gmail.com>,
        Gregory Fong <gregory.0xf0@gmail.com>,
        "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" 
        <bcm-kernel-feedback-list@broadcom.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        "moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>
References: <20181221013409.14324-1-f.fainelli@gmail.com>
 <20181221013409.14324-2-f.fainelli@gmail.com> <20190103174117.GA6613@bogus>
 <2a54c2cf-5595-ade5-fb29-40e8b6d3133e@gmail.com>
 <20190103191915.GB6613@bogus>
From:   Florian Fainelli <f.fainelli@gmail.com>
Openpgp: preference=signencrypt
Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata=
 mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR
 xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ
 X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E
 AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d
 ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX
 SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc
 nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh
 qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG
 YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME
 FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS
 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3
 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu
 pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs
 hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT
 OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c
 Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M
 oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY
 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO
 BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU
 +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE
 FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo
 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m
 vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P
 WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+
 HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW
 HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz
 Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy
 kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9
 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC
 y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU
 X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV
 HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc
 YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM
 PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H
 UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO
 iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV
 WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK
 UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS
 sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4
 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W
 t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA
 AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac
 RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+
 e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD
 UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/
 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5
 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/
 xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo
 dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI
 pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0
 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF
 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI
 M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI=
Message-ID: <bcfe4df0-8928-90e2-6460-1391320af9be@gmail.com>
Date:   Thu, 3 Jan 2019 11:31:22 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.2.1
MIME-Version: 1.0
In-Reply-To: <20190103191915.GB6613@bogus>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 1/3/19 11:19 AM, Rob Herring wrote:
> On Thu, Jan 03, 2019 at 10:53:25AM -0800, Florian Fainelli wrote:
>> On 1/3/19 9:41 AM, Rob Herring wrote:
>>> On Thu, Dec 20, 2018 at 05:34:08PM -0800, Florian Fainelli wrote:
>>>> Add a binding document for the Broadcom STB reset controller, also known
>>>> as SW_INIT-style reset controller.
>>>>
>>>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>>>> ---
>>>>  .../devicetree/bindings/reset/brcm,reset.txt  | 27 +++++++++++++++++++
>>>>  1 file changed, 27 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/reset/brcm,reset.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/reset/brcm,reset.txt b/Documentation/devicetree/bindings/reset/brcm,reset.txt
>>>> new file mode 100644
>>>> index 000000000000..6e5341b4f891
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/reset/brcm,reset.txt
>>>> @@ -0,0 +1,27 @@
>>>> +Broadcom STB SW_INIT-style reset controller
>>>> +===========================================
>>>> +
>>>> +Broadcom STB SoCs have a SW_INIT-style reset controller with separate
>>>> +SET/CLEAR/STATUS registers and possibly multiple banks, each of 32 bit
>>>> +reset lines.
>>>> +
>>>> +Please also refer to reset.txt in this directory for common reset
>>>> +controller binding usage.
>>>> +
>>>> +Required properties:
>>>> +- compatible: should be brcm,brcmstb-reset
>>>> +- reg: register base and length
>>>> +- #reset-cells: must be set to 1
>>>> +
>>>> +Example:
>>>> +
>>>> +	reset: reset-controller@8404318 {
>>>> +		compatible = "brcm,brcmstb-reset";
>>>> +		reg = <0x8404318 0x30>;
>>>
>>> Based on this address, should this be a sub-node of something else? Or 
>>> not even a sub-node and just make the parent be a reset provider?
>>
>> The reset controller is part of a larger "sundry" node which has a
>> collection of functionality, from pinmux/pinctrl, reset controller,
>> spare bits, chicken bits, anything the designers forgot to put somewhere
>> else and decided to put there.
>>
>> If there is one thing consistent though is that given a set of 32-bit
>> register groups, they have a self contained functionality such that you
>> can break up the larger "sundry" space into smaller sub-blocks which
>> have one an only one functionality. Do you think this warrants a
>> different representation in Device Tree?
> 
> With pinctrl in the mix, you're going to need sub-nodes anyways. So just 
> define what this is a sub-node of.

pinctrl is not necessarily something I want the kernel to control, since
we have a high level scripting language without our bootloader that
makes sure pinctrl is properly configured from early boot on all the way
to the kernel, and preserved across suspend/resume states.
pinctrl-single does work, and was occasionally used. Everything else is
typically muxes that the kernel does not need to touch/see/be aware of.

> 
> Also, I'd prefer to have complete example for the "sundry" node and 
> child nodes than partial examples spread across the tree.

I am afraid I can't provide that example because the sundry node is
really changing from chip to chip, and there is a gazillion of things in
there that the kernel typically does not even touch, like
pinmuxing/pinctrl, various mux selections etc. I could provide the
following example if that is what you are requesting?:


sun-top-ctrl: simple-bus@8404000 {
	compatible = "brcm,brcmstb-sun-top-ctrl", "simple-bus";
	reg = <0x8404000 0x708>;

	reset: reset-controller@318 {
		compatible = "brcm,brcmstb-reset";
		reg = <0x318 0x30>;
		#reset-cells = <1>;
	};
};

Would that be what you expect to see?
-- 
Florian