Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754852AbaLDWQe (ORCPT ); Thu, 4 Dec 2014 17:16:34 -0500 Received: from mail-wg0-f44.google.com ([74.125.82.44]:46553 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752093AbaLDWQc (ORCPT ); Thu, 4 Dec 2014 17:16:32 -0500 MIME-Version: 1.0 In-Reply-To: <1417730171-30455-2-git-send-email-rjui@broadcom.com> References: <1417730171-30455-1-git-send-email-rjui@broadcom.com> <1417730171-30455-2-git-send-email-rjui@broadcom.com> Date: Thu, 4 Dec 2014 23:16:30 +0100 Message-ID: Subject: Re: [PATCH 1/4] pinctrl: Broadcom Cygnus pinctrl device tree binding From: Belisko Marek To: Ray Jui Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Linus Walleij , Grant Likely , Christian Daudt , Matt Porter , Florian Fainelli , Russell King , "devicetree@vger.kernel.org" , Scott Branden , LKML , linux-gpio@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-arm-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 4, 2014 at 10:56 PM, Ray Jui wrote: > Device tree binding documentation for Broadcom Cygnus pinctrl driver > > Signed-off-by: Ray Jui > Reviewed-by: Scott Branden > --- > .../bindings/pinctrl/brcm,cygnus-pinctrl.txt | 92 ++++++++++++++++++++ > 1 file changed, 92 insertions(+) > create mode 100644 Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt > > diff --git a/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt > new file mode 100644 > index 0000000..86e4579 > --- /dev/null > +++ b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt > @@ -0,0 +1,92 @@ > +Broadcom Cygnus Pin Controller > + > +The Cygnus pin controller supports setting the alternate functions of groups > +of pins. Pinmux configuration on individual pins is not supported by the > +Cygnus A0 SoC. > + > +Required properties: > + > +- compatible: > + Must be "brcm,cygnus-pinctrl" > + > +- reg: > + Define the base and range of the I/O address space that contain the Cygnus > +pin control registers > + > +- brcm,groups: > + This can be strings of one or more group names. This defines the group(s) > +that one wants to configure > + > +- brcm,function: > + This is the alternate function that one wants to configure to. Valid > +alternate functions are "alt1", "alt2", "alt3", "alt4" > + > +Each child node represents a configuration. Client devices reference the the > +child node to enable the mux configuration. > + > +For example: > + > + pinctrl: pinctrl@0x0301d0c8 { > + compatible = "brcm,cygnus-pinctrl"; > + reg = <0x0301d0c8 0x2c>; > + > + i2s_0: i2s_0 { > + brcm,groups = "smart_card0", "smart_card0_fcb"; > + brcm,function = "alt2"; > + }; > + > + i2s_1: i2s_1 { > + brcm,groups = "smart_card1", "smart_card1_fcb"; > + brcm,function = "alt2"; > + }; > + > + spi_0: spi_0 { > + brcm,groups = "spi0"; > + brcm,function = "alt1"; > + }; > + } > + > + spi0@18028000 { > + compatible = "arm,pl022", "arm,primecell"; > + reg = <0x18028000 0x1000>; > + #address-cells = <1>; > + #size-cells = <0>; > + interrupts = ; > + pinctrl-0 = <&spi_0>; > + clocks = <&axi81_clk>; > + clock-names = "apb_pclk"; > + }; > + > +Consider the following snapshot of Cygnus pinmux table: > + > +number pin group alt1 alt2 alt3 alt4 > +------ --- ---- ---- ---- ---- ---- > +42 sc0_clk smart_card0 SMART CARD0 I2S_0 N/A chip_gpio24 > +43 sc0_cmdvcc_l smart_card0 SMART CARD0 I2S_0 N/A STRAP > +44 sc0_detect smart_card0 SMART CARD0 I2S_0 N/A chip_gpio25 > +45 sc0_fcb smart_card0_fcb SMART CARD0_FCB I2S_0 N/A chip_gpio26 > +46 sc0_io smart_card0 SMART CARD0 I2S_0 N/A chip_gpio27 > +47 sc0_rst_l smart_card0 SMART CARD0 SPDIF N/A STRAP > + > +Note due to limitation of the Cygnus hardware, pinmux configuration can only > +be group based. To enable I2S_0 function, one needs the following child node > +configuration: > + > + i2s_0: i2s_0 { > + brcm,groups = "smart_card0", "smart_card0_fcb"; > + brcm,function = "alt2"; > + }; > + > +This tells the Cygnus pin controller to configure groups "smart_card0" and > +"smart_card0_fcb" to I2S_0. With this configuration, pins 42, 43, 44, 45, 46 > +become I2C_0, and pin 47 becomes SPDIF ^^^^ typo - should be I2S_0 > + > +Consider another example, that one wants to configure the above pins as GPIO: > + > + gpio_24_27: gpio_24_27 { > + brcm,groups = "smart_card0", "smart_card0_fcb"; > + brcm,function = "alt4"; > + }; > + > +With the above configuration, pins 42, 44, 45, 46 become GPIO, and 43 and 47 > +become reserved for STRAP > -- > 1.7.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel BR, marek -- as simple and primitive as possible ------------------------------------------------- Marek Belisko - OPEN-NANDRA Freelance Developer Ruska Nova Ves 219 | Presov, 08005 Slovak Republic Tel: +421 915 052 184 skype: marekwhite twitter: #opennandra web: http://open-nandra.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/