From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 01/14] dt-bindings: Document STM32MP1 Reset Clock Controller (RCC) bindings Date: Wed, 7 Feb 2018 12:03:15 -0600 Message-ID: References: <1517580222-23301-1-git-send-email-gabriel.fernandez@st.com> <1517580222-23301-2-git-send-email-gabriel.fernandez@st.com> <20180205042238.64xjrrguls2drtrg@rob-hp-laptop> <19273eb9-0c8c-cd2a-d100-f25f25e93234@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <19273eb9-0c8c-cd2a-d100-f25f25e93234@st.com> Sender: linux-clk-owner@vger.kernel.org To: Gabriel FERNANDEZ Cc: Mark Rutland , Lee Jones , Maxime Coquelin , Alexandre TORGUE , Michael Turquette , Stephen Boyd , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-clk@vger.kernel.org" , "gabriel.fernandez.st@gmail.com" , Olivier BIDEAU List-Id: devicetree@vger.kernel.org On Mon, Feb 5, 2018 at 1:01 AM, Gabriel FERNANDEZ wrote: > Hi Rob, > > Thanks for reviewing. > > > On 02/05/2018 07:09 AM, Rob Herring wrote: >> On Fri, Feb 02, 2018 at 03:03:29PM +0100, gabriel.fernandez@st.com wrote: >>> From: Gabriel Fernandez >>> >>> The RCC block is responsible of the management of the clock and reset >>> generation for the complete circuit. >>> >>> Signed-off-by: Gabriel Fernandez >>> --- >>> .../devicetree/bindings/mfd/st,stm32-rcc.txt | 85 ++++++++++++++++++++++ >>> 1 file changed, 85 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/mfd/st,stm32-rcc.txt >>> >>> diff --git a/Documentation/devicetree/bindings/mfd/st,stm32-rcc.txt b/Documentation/devicetree/bindings/mfd/st,stm32-rcc.txt >>> new file mode 100644 >>> index 0000000..28017a1 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/mfd/st,stm32-rcc.txt >>> @@ -0,0 +1,85 @@ >>> +STMicroelectronics STM32 Peripheral Reset Clock Controller >>> +========================================================== >>> + >>> +The RCC IP is both a reset and a clock controller. >>> + >>> +Please also refer to reset.txt for common reset controller binding usage. >>> + >>> +Please also refer to clock-bindings.txt for common clock controller >>> +binding usage. >>> + >>> + >>> +Required properties: >>> +- compatible: "simple-mfd", "syscon" >> >>> +- reg: should be register base and length as documented in the datasheet >>> + >>> +- Sub-nodes: >>> + - compatible: "st,stm32mp1-rcc-clk" >>> + - #clock-cells: 1, device nodes should specify the clock in their >>> + "clocks" property, containing a phandle to the clock device node, >>> + an index specifying the clock to use. >>> + >>> + - compatible: "st,stm32mp1-rcc-rst" >>> + - #reset-cells: Shall be 1 >>> + >>> +Example: >>> + rcc: rcc@50000000 { >>> + compatible = "syscon", "simple-mfd"; >>> + reg = <0x50000000 0x1000>; >>> + >>> + rcc_clk: rcc-clk@50000000 { >>> + #clock-cells = <1>; >>> + compatible = "st,stm32mp1-rcc-clk"; >>> + }; >>> + >>> + rcc_rst: rcc-reset@50000000 { >> You should not have the same unit-address twice. >> >> IMO, this should just be: >> >> rcc: rcc@50000000 { >> compatible = "st-stm32mp1-rcc"; >> reg = <0x50000000 0x1000>; >> #clock-cells = <1>; >> #reset-cells = <1>; >> }; >> >> There's no reason a node can't provide more than 1 function. > RCC is an dedicated IP for clocks and resets, but also for power > management (patches will be sent later) If there's additional functions, they should be part of the binding now, not later. bindings should not unnecessarily evolve. > Then i need to probe 3 drivers with same IP. Drivers and DT nodes don't have to be 1-1. A parent driver can create additional child devices. Also, looking at your existing bindings for RCC IP, it is done as I suggested. > It's also a way to avoid use of 'CLK_OF_DECLARE_DRIVER' and i need it to > probe the 3th driver. Sounds like a Linux problem, not a DT issue. Rob