Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932219AbbEIHzI (ORCPT ); Sat, 9 May 2015 03:55:08 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:35885 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753828AbbEIHyY (ORCPT ); Sat, 9 May 2015 03:54:24 -0400 From: Maxime Coquelin To: u.kleine-koenig@pengutronix.de, afaerber@suse.de, geert@linux-m68k.org, Rob Herring , Philipp Zabel , Linus Walleij , Arnd Bergmann , stefan@agner.ch, pmeerw@pmeerw.net, pebolle@tiscali.nl, peter@hurleysoftware.com, andy.shevchenko@gmail.com, cw00.choi@samsung.com, Russell King , Daniel Lezcano , joe@perches.com, Vladimir Zapolskiy , lee.jones@linaro.org, Daniel Thompson Cc: Jonathan Corbet , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Thomas Gleixner , Greg Kroah-Hartman , Jiri Slaby , Andrew Morton , "David S. Miller" , Mauro Carvalho Chehab , Antti Palosaari , Tejun Heo , Will Deacon , Nikolay Borisov , Rusty Russell , Kees Cook , Michal Marek , linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, linux-serial@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, mcoquelin.stm32@gmail.com, Nicolae Rosia , Kamil Lulko Subject: [PATCH v8 06/16] dt-bindings: Document the STM32 reset bindings Date: Sat, 9 May 2015 09:53:48 +0200 Message-Id: <1431158038-3813-7-git-send-email-mcoquelin.stm32@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1431158038-3813-1-git-send-email-mcoquelin.stm32@gmail.com> References: <1431158038-3813-1-git-send-email-mcoquelin.stm32@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2391 Lines: 73 This adds documentation of device tree bindings for the STM32 reset controller. Signed-off-by: Maxime Coquelin --- .../devicetree/bindings/reset/st,stm32-rcc.txt | 50 ++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-rcc.txt diff --git a/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt b/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt new file mode 100644 index 0000000..333080c --- /dev/null +++ b/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt @@ -0,0 +1,50 @@ +STMicroelectronics STM32 Peripheral Reset Controller +==================================================== + +The RCC IP is both a reset and a clock controller. This documentation only +documents the reset part. + +Please also refer to reset.txt in this directory for common reset +controller binding usage. + +Required properties: +- compatible: Should be "st,stm32-rcc" +- reg: should be register base and length as documented in the + datasheet +- #reset-cells: 1, see below + +example: + +rcc: reset@40023800 { + #reset-cells = <1>; + compatible = "st,stm32-rcc"; + reg = <0x40023800 0x400>; +}; + +Specifying softreset control of devices +======================================= + +Device nodes should specify the reset channel required in their "resets" +property, containing a phandle to the reset device node and an index specifying +which channel to use. +The index is the bit number within the RCC registers bank, starting from RCC +base address. +It is calculated as: index = register_offset / 4 * 32 + bit_offset. +Where bit_offset is the bit offset within the register. +For example, for CRC reset: + crc = AHB1RSTR_offset / 4 * 32 + CRCRST_bit_offset = 0x10 / 4 * 32 + 12 = 140 + +To simplify the usagen and to share bit definition with the clock driver of +the RCC IP, macros are available to generate the index in human-readble +format. + +For STM32F4 series, the macro are available here: + - include/dt-bindings/mfd/stm32f4-rcc.h + +example: + + timer2 { + resets = <&rcc STM32F4_APB1_RESET(TIM2)>; + }; + + -- 1.9.1 -- 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/