Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756803Ab3IMAfG (ORCPT ); Thu, 12 Sep 2013 20:35:06 -0400 Received: from zetta.elopez.com.ar ([199.30.59.35]:51998 "EHLO zetta.elopez.com.ar" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780Ab3IMAfD (ORCPT ); Thu, 12 Sep 2013 20:35:03 -0400 From: =?UTF-8?q?Emilio=20L=C3=B3pez?= To: Mike Turquette , Maxime Ripard , grant.likely@linaro.org, rob.herring@calxeda.com, gregkh@linuxfoundation.org Cc: , , david.lanzendoerfer@o2s.ch, , =?UTF-8?q?Emilio=20L=C3=B3pez?= Subject: [PATCH] memory: add a basic OF-based memory driver Date: Thu, 12 Sep 2013 21:30:25 -0300 Message-Id: <1379032225-6425-1-git-send-email-emilio@elopez.com.ar> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1378863781-4235-1-git-send-email-emilio@elopez.com.ar> References: <1378863781-4235-1-git-send-email-emilio@elopez.com.ar> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4871 Lines: 147 This driver's only job is to claim and ensure the necessary clock for memory operation on a DT-powered machine remains enabled. Signed-off-by: Emilio López --- I believe this new patch should resolve all the concerns raised; as always, all feedback is welcome :) Changes from RFC: - Move from drivers/of to drivers/memory - Make a proper driver instead of using an initcall - Binding document for the new "simple-memory-controller" .../simple-memory-controller.txt | 19 ++++++++ drivers/memory/Kconfig | 11 +++++ drivers/memory/Makefile | 1 + drivers/memory/simple-mc.c | 57 ++++++++++++++++++++++ 4 files changed, 88 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory-controllers/simple-memory-controller.txt create mode 100644 drivers/memory/simple-mc.c diff --git a/Documentation/devicetree/bindings/memory-controllers/simple-memory-controller.txt b/Documentation/devicetree/bindings/memory-controllers/simple-memory-controller.txt new file mode 100644 index 0000000..d37683b --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/simple-memory-controller.txt @@ -0,0 +1,19 @@ +Device Tree Clock binding for a simple memory controller. + +Required properties: +- compatible : shall be "simple-memory-controller" + +Optional properties: +- reg : may contain the register space for the controller. This + property is currently ignored by the driver +- clocks : may contain a phandle to the clock that is currently being + used on the controller. This clock shall remain enabled + during system operation. + +Example: + +mc: mc@0123000 { + compatible = "simple-memory-controller"; + reg = <0x0123000 0x400>; + clocks = <&pll5 1>; +}; diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig index 29a11db..4a6df65 100644 --- a/drivers/memory/Kconfig +++ b/drivers/memory/Kconfig @@ -50,4 +50,15 @@ config TEGRA30_MC analysis, especially for IOMMU/SMMU(System Memory Management Unit) module. +config SIMPLE_MC + bool "Simple memory controller" + default y + depends on OF && COMMON_CLK + help + This driver is able to manage a simple memory controller whose + only needs consist of keeping one clock enabled. The + controller must be defined on the device tree as compatible + with "simple-memory-controller"; see the corresponding binding + document for more details. + endif diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile index 969d923..e0953e5 100644 --- a/drivers/memory/Makefile +++ b/drivers/memory/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_TI_EMIF) += emif.o obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o +obj-$(CONFIG_SIMPLE_MC) += simple-mc.o diff --git a/drivers/memory/simple-mc.c b/drivers/memory/simple-mc.c new file mode 100644 index 0000000..e58371d --- /dev/null +++ b/drivers/memory/simple-mc.c @@ -0,0 +1,57 @@ +/* + * Simple memory controller driver + * + * Copyright 2013 Emilio López + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include + +static int simple_mc_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct clk *clk; + + if (!np) + return -ENODEV; + + clk = of_clk_get(np, 0); + if (!IS_ERR(clk)) { + clk_prepare_enable(clk); + clk_put(clk); + } + + return 0; +} + +static const struct of_device_id simple_mc_of_match[] = { + { .compatible = "simple-memory-controller", }, + { /* sentinel */ }, +}; + +static struct platform_driver simple_mc_driver = { + .probe = simple_mc_probe, + .driver = { + .name = "simple-mc", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(simple_mc_of_match), + }, +}; + +module_platform_driver(simple_mc_driver); + +MODULE_AUTHOR("Emilio López "); +MODULE_DESCRIPTION("Simple memory controller driver"); +MODULE_LICENSE("GPL"); -- 1.8.4 -- 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/