From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v7 1/2] mfd: devicetree: add bindings for Atmel Flexcom Date: Fri, 24 Jul 2015 16:07:35 +0100 Message-ID: <20150724150735.GH3436@x1> References: <60057bbf7d39ec63d391d26271747cf0228a3ed1.1437669004.git.cyrille.pitchen@atmel.com> <20150723214857.4322c758@bbrezillon> <55B1F9B7.2080206@atmel.com> <20150724145613.GG3436@x1> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20150724145613.GG3436@x1> Sender: linux-kernel-owner@vger.kernel.org To: Nicolas Ferre Cc: Boris Brezillon , Cyrille Pitchen , alexandre.belloni@free-electrons.com, sameo@linux.intel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On Fri, 24 Jul 2015, Lee Jones wrote: > On Fri, 24 Jul 2015, Nicolas Ferre wrote: >=20 > > Le 23/07/2015 21:48, Boris Brezillon a =C3=A9crit : > > > On Thu, 23 Jul 2015 18:42:55 +0200 > > > Cyrille Pitchen wrote: > > >=20 > > >> This patch documents the DT bindings for the Atmel Flexcom which= will be > > >> introduced by sama5d2x SoCs. These bindings will be used by the = actual > > >> Flexcom driver to be sent in another patch. > > >> > > >> Signed-off-by: Cyrille Pitchen > > >> --- > > >> .../devicetree/bindings/mfd/atmel-flexcom.txt | 68 +++++++= +++++++++++++++ > > >> 1 file changed, 68 insertions(+) > > >> create mode 100644 Documentation/devicetree/bindings/mfd/atmel-= flexcom.txt > > >> > > >> diff --git a/Documentation/devicetree/bindings/mfd/atmel-flexcom= =2Etxt b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt > > >> new file mode 100644 > > >> index 000000000000..a63226b7a9cb > > >> --- /dev/null > > >> +++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt > > >> @@ -0,0 +1,68 @@ > > >> +* Device tree bindings for Atmel Flexcom (Flexible Serial Commu= nication Unit) > > >> + > > >> +The Atmel Flexcom is just a wrapper which embeds a SPI controll= er, an I2C > > >> +controller and an USART. Only one function can be used at a tim= e and is chosen > > >> +at boot time according to the device tree. > > >> + > > >> +Required properties: > > >> +- compatible: Should be "atmel,sama5d2-flexcom" > > >> +- reg: Should be the pair (offset, size) for the Flexcom > > >> + dedicated I/O registers (without USART, TWI or SPI > > >> + registers). > > >> +- clocks: Should be the Flexcom peripheral clock from PMC. > > >> +- #address-cells: Should be <2> > > >> +- #size-cells: Should be <1> > > >> +- ranges: Should be a list of ranges. > > >> + One range per peripheral wrapped by the Flexcom. So each > > >> + range is a triplet (child_addr, parent_addr, size). The > > >> + first u32 of "child_addr" is the value to be set in the > > >> + Operating Mode bitfield of the Flexcom Mode Register. > > >> + Then "parent_addr" stores the base address of the > > >> + corresponding peripheral in the system memory. Finally, > > >> + "size" if the size of the memory region of this > > >> + peripheral. > > >> + > > >> +Required child: > > >> +A single available child for the serial controller to enable. > > >> + > > >> +Required properties of this child: > > >> +- reg: Should be a pair (child_addr, size) with child_addr > > >> + matching one of the parent ranges. > > >> +- clocks: Should be the very same phandle as for the parent's = one. > > >> + > > >> +Other properties remain unchanged. See documentation of the res= pective device: > > >> +- ../serial/atmel-usart.txt > > >> +- ../spi/spi_atmel.txt > > >> +- ../i2c/i2c-at91.txt > > >> + > > >> +Example: > > >> + > > >> +flexcom@f8034000 { > > >> + compatible =3D "atmel,sama5d2-flexcom"; > > >> + reg =3D <0xf8034000 0x200>; > > >> + clocks =3D <&flx0_clk>; > > >> + #address-cells =3D <2>; > > >> + #size-cells =3D <1>; > > >> + ranges =3D <1 0 0xf8034200 0x200 /* opmode 1: USART */ > > >> + 2 0 0xf8034400 0x200 /* opmode 2: SPI */ > > >> + 3 0 0xf8034600 0x200>; /* opmode 3: I2C */ > >=20 > > Yes, the opmode(s) are exactly the values described in the product > > datasheet. > >=20 > > >> + > > >> + spi@f8034400 { > > >=20 > > > Should be: > > >=20 > > > spi@2,0 { > >=20 > > Yep! > >=20 > > I was silently following the discussion in the background and I adm= it > > that this approach is pretty elegant. > >=20 > > So, if this approach is validated you can also add my: > > Acked-by: Nicolas Ferre >=20 > Please see my reply to v6 for the usual way to achieve this. Ah, actually scrap that. Looks like I was thinking you were doing something different. Well I don't know enough about the advanced use of the ranges property to comment on this. I need to call for some assistance from the DT chaps. > > >> + compatible =3D "atmel,at91rm9200-spi"; > > >> + reg =3D <2 0 0x200>; > > >> + interrupts =3D <19 IRQ_TYPE_LEVEL_HIGH 7>; > > >> + pinctrl-names =3D "default"; > > >> + pinctrl-0 =3D <&pinctrl_flx0_default>; > > >> + #address-cells =3D <1>; > > >> + #size-cells =3D <0>; > > >> + clocks =3D <&flx0_clk>; > > >> + clock-names =3D "spi_clk"; > > >> + atmel,fifo-size =3D <32>; > > >> + > > >> + mtd_dataflash@0 { > > >> + compatible =3D "atmel,at25f512b"; > > >> + reg =3D <0>; > > >> + spi-max-frequency =3D <20000000>; > > >> + }; > > >> + }; > > >> +}; > > >=20 > > >=20 > > >=20 > >=20 > >=20 >=20 --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog