Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965184Ab2JZQIE (ORCPT ); Fri, 26 Oct 2012 12:08:04 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:60210 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933818Ab2JZQIB (ORCPT ); Fri, 26 Oct 2012 12:08:01 -0400 MIME-Version: 1.0 In-Reply-To: <1350570453-24546-3-git-send-email-p.zabel@pengutronix.de> References: <1350570453-24546-1-git-send-email-p.zabel@pengutronix.de> <1350570453-24546-3-git-send-email-p.zabel@pengutronix.de> From: Paul Gortmaker Date: Fri, 26 Oct 2012 12:07:30 -0400 X-Google-Sender-Auth: BlsJJHK9tovTe71hNwFkJay7XcE Message-ID: Subject: Re: [PATCH v5 2/4] misc: Generic on-chip SRAM allocation driver To: Philipp Zabel Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , Greg Kroah-Hartman , Grant Likely , Rob Herring , Shawn Guo , Richard Zhao , Huang Shijie , Dong Aisheng , Matt Porter , kernel@pengutronix.de, devicetree-discuss@lists.ozlabs.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7356 Lines: 222 On Thu, Oct 18, 2012 at 10:27 AM, Philipp Zabel wrote: > This driver requests and remaps a memory region as configured in the > device tree. It serves memory from this region via the genalloc API. > > Other drivers can retrieve the genalloc pool from a phandle pointing > to this drivers' device node in the device tree. > > Signed-off-by: Philipp Zabel > Reviewed-by: Shawn Guo > --- > Documentation/devicetree/bindings/misc/sram.txt | 17 ++++ > drivers/misc/Kconfig | 9 ++ > drivers/misc/Makefile | 1 + > drivers/misc/sram.c | 111 +++++++++++++++++++++++ > 4 files changed, 138 insertions(+) > create mode 100644 Documentation/devicetree/bindings/misc/sram.txt > create mode 100644 drivers/misc/sram.c > > diff --git a/Documentation/devicetree/bindings/misc/sram.txt b/Documentation/devicetree/bindings/misc/sram.txt > new file mode 100644 > index 0000000..b64136c > --- /dev/null > +++ b/Documentation/devicetree/bindings/misc/sram.txt > @@ -0,0 +1,17 @@ > +Generic on-chip SRAM > + > +Simple IO memory regions to be managed by the genalloc API. > + > +Required properties: > + > +- compatible : sram > + > +- reg : SRAM iomem address range > + > +Example: > + > +sram: sram@5c000000 { > + compatible = "sram"; > + reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */ > +}; > + > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig > index b151b7c..c5bbd00 100644 > --- a/drivers/misc/Kconfig > +++ b/drivers/misc/Kconfig > @@ -499,6 +499,15 @@ config USB_SWITCH_FSA9480 > stereo and mono audio, video, microphone and UART data to use > a common connector port. > > +config SRAM > + bool "Generic on-chip SRAM driver" If it is bool, then why bother with module.h and all the MODULE_AUTHOR and similar stuff? > + depends on HAS_IOMEM > + select GENERIC_ALLOCATOR > + help > + This driver allows to declare a memory region to be managed > + by the genalloc API. It is supposed to be used for small > + on-chip SRAM areas found on many ARM SoCs. Probably no need to call out ARM specifically here. I'm pretty sure quite a few of the powerpc parts have SRAM too. > + > source "drivers/misc/c2port/Kconfig" > source "drivers/misc/eeprom/Kconfig" > source "drivers/misc/cb710/Kconfig" > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile > index 2129377..d845690 100644 > --- a/drivers/misc/Makefile > +++ b/drivers/misc/Makefile > @@ -49,3 +49,4 @@ obj-y += carma/ > obj-$(CONFIG_USB_SWITCH_FSA9480) += fsa9480.o > obj-$(CONFIG_ALTERA_STAPL) +=altera-stapl/ > obj-$(CONFIG_INTEL_MEI) += mei/ > +obj-$(CONFIG_SRAM) += sram.o > diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c > new file mode 100644 > index 0000000..7a363f2 > --- /dev/null > +++ b/drivers/misc/sram.c > @@ -0,0 +1,111 @@ > +/* > + * Generic on-chip SRAM allocation driver > + * > + * Copyright (C) 2012 Philipp Zabel, Pengutronix > + * > + * 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. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, > + * MA 02110-1301, USA. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct sram_dev { > + struct gen_pool *pool; > +}; Assuming you don't ever intend adding more to the struct, then: static struct gen_pool *sram_pool; instead? And you'll lose the needless indirections in the remaining code below, and the kzalloc too (which you currently leak, btw). I'd also delete the "/* sentinel */" comment too, since it is self evident. (The disease has spread by copying from other drivers I see). P. -- > + > +static int __devinit sram_probe(struct platform_device *pdev) > +{ > + void __iomem *virt_base; > + struct sram_dev *sram; > + struct resource *res; > + unsigned long size; > + int ret; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -EINVAL; > + > + size = resource_size(res); > + > + virt_base = devm_request_and_ioremap(&pdev->dev, res); > + if (!virt_base) > + return -EADDRNOTAVAIL; > + > + sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); > + if (!sram) > + return -ENOMEM; > + > + sram->pool = gen_pool_create(PAGE_SHIFT, -1); > + if (!sram->pool) > + return -ENOMEM; > + > + ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base, > + res->start, size, -1); > + if (ret < 0) { > + gen_pool_destroy(sram->pool); > + return ret; > + } > + > + platform_set_drvdata(pdev, sram); > + > + dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base); > + > + return 0; > +} > + > +static int __devexit sram_remove(struct platform_device *pdev) > +{ > + struct sram_dev *sram = platform_get_drvdata(pdev); > + > + if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) > + dev_dbg(&pdev->dev, "removed while SRAM allocated\n"); > + > + gen_pool_destroy(sram->pool); > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static struct of_device_id sram_dt_ids[] = { > + { .compatible = "sram" }, > + { /* sentinel */ } > +}; > +#endif > + > +static struct platform_driver sram_driver = { > + .driver = { > + .name = "sram", > + .of_match_table = of_match_ptr(sram_dt_ids), > + }, > + .probe = sram_probe, > + .remove = __devexit_p(sram_remove), > +}; > + > +int __init sram_init(void) > +{ > + return platform_driver_register(&sram_driver); > +} > + > +postcore_initcall(sram_init); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Philipp Zabel, Pengutronix"); > +MODULE_DESCRIPTION("Generic SRAM allocator driver"); > -- > 1.7.10.4 > > -- > 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/ -- 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/