From patchwork Wed Jun 22 16:22:23 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: thomas.abraham@linaro.org X-Patchwork-Id: 2176 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 3BE0423E52 for ; Wed, 22 Jun 2011 16:22:26 +0000 (UTC) Received: from mail-vx0-f180.google.com (mail-vx0-f180.google.com [209.85.220.180]) by fiordland.canonical.com (Postfix) with ESMTP id E3F15A1834B for ; Wed, 22 Jun 2011 16:22:25 +0000 (UTC) Received: by vxd7 with SMTP id 7so1069556vxd.11 for ; Wed, 22 Jun 2011 09:22:25 -0700 (PDT) Received: by 10.52.168.65 with SMTP id zu1mr1210461vdb.207.1308759745274; Wed, 22 Jun 2011 09:22:25 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.52.183.130 with SMTP id em2cs149022vdc; Wed, 22 Jun 2011 09:22:24 -0700 (PDT) Received: by 10.224.180.68 with SMTP id bt4mr679024qab.110.1308759744066; Wed, 22 Jun 2011 09:22:24 -0700 (PDT) Received: from mail-qw0-f50.google.com (mail-qw0-f50.google.com [209.85.216.50]) by mx.google.com with ESMTPS id t2si990416qcs.206.2011.06.22.09.22.23 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 22 Jun 2011 09:22:24 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.216.50 is neither permitted nor denied by best guess record for domain of thomas.abraham@linaro.org) client-ip=209.85.216.50; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.216.50 is neither permitted nor denied by best guess record for domain of thomas.abraham@linaro.org) smtp.mail=thomas.abraham@linaro.org Received: by qwe5 with SMTP id 5so575211qwe.37 for ; Wed, 22 Jun 2011 09:22:23 -0700 (PDT) MIME-Version: 1.0 Received: by 10.224.195.193 with SMTP id ed1mr642388qab.231.1308759743767; Wed, 22 Jun 2011 09:22:23 -0700 (PDT) Received: by 10.224.60.71 with HTTP; Wed, 22 Jun 2011 09:22:23 -0700 (PDT) In-Reply-To: References: <1308567752-13451-1-git-send-email-thomas.abraham@linaro.org> <1308567752-13451-3-git-send-email-thomas.abraham@linaro.org> Date: Wed, 22 Jun 2011 21:52:23 +0530 Message-ID: Subject: Re: [PATCH 2/6] serial: samsung: Add device tree support for s5pv210 uart driver From: Thomas Abraham To: Grant Likely Cc: devicetree-discuss@lists.ozlabs.org, kgene.kim@samsung.com, linaro-dev@lists.linaro.org, patches@linaro.org, linux-samsung-soc@vger.kernel.org, ben-linux@fluff.org, linux-arm-kernel@lists.infradead.org Hi Grant, On 20 June 2011 22:13, Grant Likely wrote: > Okay, this is getting ugly (not your fault, but this pattern has > become too common.  Can you craft and post a patch that adds the > following functions to drivers/of/base.c and include/linux/of.h > > /* offset in cells, not bytes */ > int dt_decode_u32(struct *property, int offset, u32 *out_val) > { >        if (!property || !property->value) >                return -EINVAL; >        if ((offset + 1) * 4 > property->length) >                return -EINVAL; >        *out_val = of_read_number(property->value + (offset * 4), 1); >        return 0; > } > int dt_decode_u64(struct *property, int offset, u64 *out_val) > { > ... > } > int dt_decode_string(struct *property, int index, char **out_string); > { > ... > } > > Plus a set of companion functions: > int dt_getprop_u32(struct device_node *np, char *propname, int offset, > u32 *out_val) > { >        return dt_decode_u32(of_find_property(np, propname, NULL), > offset, out_val); > } > int dt_getprop_u64(struct *device_node, char *propname, int offset, > u64 *out_val); > { > ... > } > int dt_getprop_string(struct *device_node, char *propname, int index, > char **out_string); > { > ... > } > > Then you'll be able to simply do the following to decode each > property, with fifosize being left alone if the property cannot be > found or decoded: > > dt_getprop_u32(pdev->dev.of_node, "samsung,fifosize", &fifosize); I have added the functions as you have suggested and the diff is listed below. Could you please review the diff and suggest any changes required. drivers/of/base.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 10 ++++ 2 files changed, 139 insertions(+), 0 deletions(-) extern int of_device_is_available(const struct device_node *device); diff --git a/drivers/of/base.c b/drivers/of/base.c index 632ebae..73f0144 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -596,6 +596,135 @@ struct device_node *of_find_node_by_phandle(phandle handle) EXPORT_SYMBOL(of_find_node_by_phandle); /** + * of_read_property_u32 - Reads a indexed 32-bit property value + * @prop: property to read from. + * @offset: cell number to read. + * value: returned cell value + * + * Returns a indexed 32-bit value of a property cell, -EINVAL in case the cell + * does not exist + */ +int of_read_property_u32(struct property *prop, u32 offset, u32 *value) +{ + if (!prop || !prop->value) + return -EINVAL; + if ((offset + 1) * 4 > prop->length) + return -EINVAL; + + *value = of_read_ulong(prop->value + (offset * 4), 1); + return 0; +} +EXPORT_SYMBOL(of_read_property_u32); + +/** + * of_getprop_u32 - Find a property in a device node and read a 32-bit value + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read. + * @value: returned value of the cell + * + * Search for a property in a device node and read a indexed 32-bit value of a + * property cell. Returns the 32-bit cell value, -EINVAL in case the property or + * the indexed cell does not exist. + */ +int +of_getprop_u32(struct device_node *np, char *propname, int offset, u32 *value) +{ + return of_read_property_u32(of_find_property(np, propname, NULL), + offset, value); +} +EXPORT_SYMBOL(of_getprop_u32); + +/** + * of_read_property_u64 - Reads a indexed 64-bit property value + * @prop: property to read from. + * @offset: cell number to read (each cell is 64-bits). + * @value: returned cell value + * + * Returns a indexed 64-bit value of a property cell, -EINVAL in case the cell + * does not exist + */ +int of_read_property_u64(struct property *prop, int offset, u64 *value) +{ + if (!prop || !prop->value) + return -EINVAL; + if ((offset + 1) * 8 > prop->length) + return -EINVAL; + + *value = of_read_number(prop->value + (offset * 8), 2); + return 0; +} +EXPORT_SYMBOL(of_read_property_u64); + +/** + * of_getprop_u64 - Find a property in a device node and read a 64-bit value + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read (each cell is 64-bits). + * @value: returned value of the cell + * + * Search for a property in a device node and read a indexed 64-bit value of a + * property cell. Returns the 64-bit cell value, -EINVAL in case the property or + * the indexed cell does not exist. + */ +int +of_getprop_u64(struct device_node *np, char *propname, int offset, u64 *value) +{ + return of_read_property_u64(of_find_property(np, propname, NULL), + offset, value); +} +EXPORT_SYMBOL(of_getprop_u64); + +/** + * of_read_property_string - Returns a pointer to a indexed null terminated + * property value string + * @prop: property to read from. + * @offset: index of the property string to be read. + * @string: pointer to a null terminated string, valid only if the return + * value is 0. + * + * Returns a pointer to a indexed null terminated property cell string, -EINVAL + * in case the cell does not exist. + */ +int of_read_property_string(struct property *prop, int offset, char **string) +{ + char *c; + + if (!prop || !prop->value) + return -EINVAL; + + c = (char *)prop->value; + while (offset--) + while (*c++) + ; + + *string = c; + return 0; +} + +/** + * of_getprop_string - Find a property in a device node and read a null + * terminated string property + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read (each cell contains a null-terminated + * string). + * @string: pointer to a null terminated string, valid only if the return + * value is 0. + * + * Search for a property in a device node and return a pointer to a indexed + * string value of a property cell. Returns a pointer to a string, -EINVAL + * in case the property or the indexed cell does not exist. + */ +int of_getprop_string(struct device_node *np, char *propname, int offset, + char **string) +{ + return of_read_property_string(of_find_property(np, propname, NULL), + offset, string); +} +EXPORT_SYMBOL(of_getprop_string); + +/** * of_parse_phandle - Resolve a phandle property to a device_node pointer * @np: Pointer to device node holding phandle property * @phandle_name: Name of property holding a phandle value diff --git a/include/linux/of.h b/include/linux/of.h index bfc0ed1..aff2786 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -195,6 +195,16 @@ extern struct device_node *of_find_node_with_property( extern struct property *of_find_property(const struct device_node *np, const char *name, int *lenp); +extern int of_read_property_u32(struct property *prop, u32 offset, u32 *value); +extern int of_getprop_u32(struct device_node *np, char *propname, int offset, + u32 *value); +extern int of_read_property_u64(struct property *prop, int offset, u64 *value); +extern int of_getprop_u64(struct device_node *np, char *propname, int offset, + u64 *value); +extern int of_read_property_string(struct property *prop, int offset, + char **string); +extern int of_getprop_string(struct device_node *np, char *propname, int offset, + char **string); extern int of_device_is_compatible(const struct device_node *device, const char *);