Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753580AbaG2Lmg (ORCPT ); Tue, 29 Jul 2014 07:42:36 -0400 Received: from ns.mm-sol.com ([37.157.136.199]:43119 "EHLO extserv.mm-sol.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753356AbaG2Lme (ORCPT ); Tue, 29 Jul 2014 07:42:34 -0400 Message-ID: <53D788A7.4020303@mm-sol.com> Date: Tue, 29 Jul 2014 14:42:31 +0300 From: Stanimir Varbanov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Grant Likely , Rob Herring , Rob Herring CC: Lee Jones , "linux-arm-msm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , linux-arm-kernel@lists.infradead.org, Stephen Boyd , Mark Brown Subject: use IORESOURCE_REG resource type for non-translatable addresses in DT Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, While looking in MFD drivers I saw that few of them (88pm860x-core, max8925-core and wm831x-core) allow use of IORESOURCE_REG as resource type when calling platform_get_resource() by their child drivers. The resources for these child devices are filled by core MFD driver manually and then passed to mfd_add_devices() as mfd_cells. During development and review comments of the MFD core driver for Qualcomm SPMI PMICs we came down to a need to describe PMIC peripheral addresses (the PMIC sub-functions) through *reg* property in DT. The PMIC peripheral drivers will be scattered over the /drivers and they will call platform_get_resource() to extract their peripheral base addresses from resource->start. The issue we have encountered is that these addresses are non-translatable thus of_address_to_resource returns OF_BAD_ADDR. Stephen Boyd have made a suggestion to solve the issue here [1]. Is that approach acceptable? Or do we have better way? How similar issues could be solved. Our DT node for SPMI PMICs can be seen below [2]. Please do comment. PS: I have made a little change in __of_address_to_resource() to illustrate what I meant above. diff --git a/drivers/of/address.c b/drivers/of/address.c index 5edfcb0..898741e 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -617,9 +617,24 @@ static int __of_address_to_resource(struct device_node *dev, if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0) return -EINVAL; + taddr = of_translate_address(dev, addrp); - if (taddr == OF_BAD_ADDR) - return -EINVAL; + /* + * if the address is non-translatable to cpu physical address + * fallback to a IORESOURCE_REG resource. + */ + if (taddr == OF_BAD_ADDR) { + memset(r, 0, sizeof(*r)); + taddr = of_read_number(addrp, 1); + if (taddr == OF_BAD_ADDR) + return -EINVAL; + r->start = taddr; + r->end = taddr + size - 1; + r->flags = IORESOURCE_REG; + r->name = name ? name : dev->full_name; + return 0; + } + memset(r, 0, sizeof(struct resource)); if (flags & IORESOURCE_IO) { unsigned long port; [1] https://lkml.org/lkml/2014/7/17/680 [2] Simplistic PMIC DT node. spmi@fc4cf000 { compatible = "qcom,spmi-pmic-arb"; reg = <0xfc4cf000 0x1000>, <0xfc4cb000 0x1000>, <0xfc4ca000 0x1000>; reg-names = "core", "intr", "cnfg"; #address-cells = <2>; #size-cells = <0>; interrupt-controller; #interrupt-cells = <4>; pm8941@0 { compatible = "qcom,pm8941"; reg = <0x0 SPMI_USID>; #size-cells = <1>; #address-cells = <1>; rtc { compatible = "qcom,pm8941-rtc"; reg = <0x6000 0x100>, <0x6100 0x100>; reg-names = "rtc", "alarm"; interrupts = <0x0 0x61 0x1 0>; interrupt-names = "alarm"; }; }; pm8941@1 { compatible = "qcom,pm8941"; reg = <0x1 SPMI_USID>; }; } -- regards, Stan -- 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/