Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754057Ab2KGEWL (ORCPT ); Tue, 6 Nov 2012 23:22:11 -0500 Received: from mail-vb0-f46.google.com ([209.85.212.46]:33761 "EHLO mail-vb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753520Ab2KGEWJ convert rfc822-to-8bit (ORCPT ); Tue, 6 Nov 2012 23:22:09 -0500 MIME-Version: 1.0 In-Reply-To: <50991C41.50705@gmail.com> References: <64c5278ebdec503f83e9b7002bf13affb7f3260f.1351225085.git.viresh.kumar@linaro.org> <50991C41.50705@gmail.com> Date: Wed, 7 Nov 2012 09:52:05 +0530 X-Google-Sender-Auth: aav8_QFrP-7XSqVZ080uyG2b-2M Message-ID: Subject: Re: [PATCH Resend V2] dt: add helper function to read u8 & u16 variables & arrays From: viresh kumar To: Rob Herring Cc: rob.herring@calxeda.com, grant.likely@secretlab.ca, linaro-dev@lists.linaro.org, andriy.shevchenko@intel.com, patches@linaro.org, devicetree-discuss@lists.ozlabs.org, spear-devel@list.st.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4259 Lines: 112 On Tue, Nov 6, 2012 at 7:48 PM, Rob Herring wrote: >> +#define of_property_read_array(_np, _pname, _out, _sz) \ >> + while (_sz--) \ >> + *_out++ = (typeof(*_out))be32_to_cpup(_val++); \ > This will not work. You are incrementing _out by 1, 2, or 4 bytes, but > _val is always incremented by 4 bytes. > > According to the dtc commit adding this feature, the values are packed: > > With this patch the following property assignment: > > property = /bits/ 16 <0x1234 0x5678 0x0 0xffff>; > > is equivalent to: > > property = <0x12345678 0x0000ffff>; I thought of it a bit more and wasn't actually aligned with your explanation :( If that is the case, how will current implementation of u32 array will work if we pass something like: 0x88 0x84000000 0x5890 from DT? So, i did a dummy test of my current implementation, with following changes in one of my drivers: dts changes: cluster0: cluster@0 { + data1 = <0x50 0x60 0x70>; + data2 = <0x5000 0x6000 0x7000>; + data3 = <0x50000000 0x60000000 0x70000000>; } driver changes: +void test(struct device_node *cluster) +{ + u8 data1[3]; + u16 data2[3]; + u32 data3[3], i; + + of_property_read_u8_array(cluster, "data1", data1, 3); + of_property_read_u16_array(cluster, "data2", data2, 3); + of_property_read_u32_array(cluster, "data3", data3, 3); + + for (i = 0; i < 3; i++) { + printk(KERN_INFO "u8 %d: %x\n", i, data1[i]); + printk(KERN_INFO "u16 %d: %x\n", i, data2[i]); + printk(KERN_INFO "u32 %d: %x\n", i, data3[i]); + } +} And following is the output [??? 4.087205] u8 0: 50 [??? 4.093746] u16 0: 5000 [??? 4.101067] u32 0: 50000000 [??? 4.109512] u8 1: 60 [??? 4.116036] u16 1: 6000 [??? 4.123357] u32 1: 60000000 [??? 4.131718] u8 2: 70 [??? 4.138241] u16 2: 7000 [??? 4.145573] u32 2: 70000000 which looks to be what we were looking for, isn't it? Following is fixup for the doc comment missing: commit 00803aed0781de451048df0d15a3e8c814a343c8 Author: Viresh Kumar Date: Wed Nov 7 09:48:46 2012 +0530 fixup! dt: add helper function to read u8 & u16 variables & arrays --- drivers/of/base.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index fbb634b..4a6632e 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -669,6 +669,7 @@ EXPORT_SYMBOL(of_find_node_by_phandle); * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_value: pointer to return value, modified only if return value is 0. + * @sz: number of array elements to read * * Search for a property in a device node and read 8-bit value(s) from * it. Returns 0 on success, -EINVAL if the property does not exist, @@ -690,6 +691,7 @@ EXPORT_SYMBOL_GPL(of_property_read_u8_array); * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_value: pointer to return value, modified only if return value is 0. + * @sz: number of array elements to read * * Search for a property in a device node and read 16-bit value(s) from * it. Returns 0 on success, -EINVAL if the property does not exist, @@ -712,6 +714,7 @@ EXPORT_SYMBOL_GPL(of_property_read_u16_array); * @np: device node from which the property value is to be read. * @propname: name of the property to be searched. * @out_value: pointer to return value, modified only if return value is 0. + * @sz: number of array elements to read * * Search for a property in a device node and read 32-bit value(s) from * it. Returns 0 on success, -EINVAL if the property does not exist, -- 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/