Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752632AbbEFLoZ (ORCPT ); Wed, 6 May 2015 07:44:25 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:34836 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751403AbbEFLoV (ORCPT ); Wed, 6 May 2015 07:44:21 -0400 Date: Wed, 6 May 2015 13:44:17 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, Rob Herring , Russell King , Will Deacon , Ivaylo Dimitrov , Sebastian Reichel , Pavel Machek , Tony Lindgren , Andreas =?utf-8?Q?F=C3=A4rber?= , linux-omap@vger.kernel.org, "linux-kernel@vger.kernel.org" , devicetree@vger.kernel.org Subject: Re: [RESEND] [PATCH v2 1/2] arm: devtree: Set system_rev from DT revision Message-ID: <20150506114417.GI30910@pali> References: <1430902142-17035-1-git-send-email-pali.rohar@gmail.com> <3577431.y872Foi4kj@wuerfel> <20150506103752.GG30910@pali> <3529567.PeFp1NNa1q@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3529567.PeFp1NNa1q@wuerfel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5828 Lines: 114 On Wednesday 06 May 2015 13:04:01 Arnd Bergmann wrote: > On Wednesday 06 May 2015 12:37:52 Pali Rohár wrote: > > On Wednesday 06 May 2015 11:31:15 Arnd Bergmann wrote: > > > On Wednesday 06 May 2015 10:49:01 Pali Rohár wrote: > > > > With this patch "revision" DT string entry is used to set global system_rev > > > > variable. DT "revision" is expected to be string with one hexadecimal number. > > > > So "Revision" line in /proc/cpuinfo will be same as "revision" DT value. > > > > > > > > Signed-off-by: Pali Rohár > > > > Acked-by: Pavel Machek > > > > > > +devicetree mailing list > > > > > > The property needs to be specified in a binding somewhere. > > > > > > > @@ -246,5 +247,14 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) > > > > /* Change machine number to match the mdesc we're using */ > > > > __machine_arch_type = mdesc->nr; > > > > > > > > + /* Set system revision from DT */ > > > > + prop = of_get_flat_dt_prop(dt_root, "revision", &size); > > > > + if (prop && size > 0) { > > > > + char revision[11]; > > > > + strlcpy(revision, prop, min(size, (int)sizeof(revision))); > > > > + if (kstrtouint(revision, 16, &system_rev) != 0) > > > > + system_rev = 0; > > > > + } > > > > + > > > > return mdesc; > > > > } > > > > > > > > > > What is the reason for doing it this early? I think it would be nicer to do > > > it after unflattening the DT. > > > > > > > It needs to be done in this code, so "system_rev" variable is set > > properly... > > What I mean is which code accesses this variable that early? > ATAG code is doing it at same early stage, so I added it to same early stage... > > > Also, it seems strange to have a string property and then use kstrtouint > > > to convert it into a number. I think it should either be specified in a DT > > > binding to be a string and then have the kernel not assume that it is a number, > > > or we should define it to be binary. > > > > > > Arnd > > > > Variable "system_rev" is number and it always was. So chaning type will > > break more parts. > > > > And it is string DT property to be human readable. Some other developers > > suggested for v2 to change it to string (from number). > > Both of them would be human readable, you just use something else to > read them ;-) > > If we have a string here, we should just change all uses of system_rev > in the kernel accordingly, there are only a few of them: > > $ git grep -w system_rev > arch/arm/include/asm/system_info.h:extern unsigned int system_rev; > arch/arm/kernel/atags_parse.c: system_rev = tag->u.revision.rev; > arch/arm/kernel/setup.c:unsigned int system_rev; > arch/arm/kernel/setup.c:EXPORT_SYMBOL(system_rev); > arch/arm/kernel/setup.c: seq_printf(m, "Revision\t: %04x\n", system_rev); > arch/arm/mach-clps711x/devices.c: system_rev = SYSFLG1_VERID(readl(base + SYSFLG1)); > arch/arm/mach-clps711x/devices.c: soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%u", system_rev); > arch/arm/mach-davinci/board-da850-evm.c: switch (system_rev & 0xF) { > arch/arm/mach-imx/mach-imx27_visstrim_m10.c: system_rev = 0x27000; > arch/arm/mach-imx/mach-imx27_visstrim_m10.c: system_rev |= (mo_version << MOTHERBOARD_SHIFT); > arch/arm/mach-imx/mach-imx27_visstrim_m10.c: system_rev |= (exp_version << EXPBOARD_SHIFT); > arch/arm/mach-imx/mach-imx27_visstrim_m10.c: mo_version = (system_rev >> MOTHERBOARD_SHIFT) & VERSION_MASK; > arch/arm/mach-ixp4xx/goramo_mlr.c: system_rev = __raw_readl(flash + CFG_REV); > arch/arm/mach-omap2/board-rx51-peripherals.c: if ((system_rev >= SYSTEM_REV_S_USES_VAUX3 && system_rev < 0x100) || > arch/arm/mach-omap2/board-rx51-peripherals.c: system_rev >= SYSTEM_REV_B_USES_VAUX3) { > arch/arm/mach-orion5x/dns323-setup.c: if (machine_is_dns323() && system_rev == DNS323_REV_A1) > arch/arm/mach-orion5x/dns323-setup.c: system_rev = dns323_identify_rev(); > arch/arm/mach-orion5x/dns323-setup.c: pr_info("DNS-323: Identified HW revision %c1\n", 'A' + system_rev); > arch/arm/mach-orion5x/dns323-setup.c: switch(system_rev) { > arch/arm/mach-orion5x/dns323-setup.c: switch(system_rev) { > arch/arm/mach-orion5x/dns323-setup.c: switch(system_rev) { > arch/arm/mach-pxa/cm-x300.c: if (system_rev < 130) > arch/arm/mach-pxa/cm-x300.c: if (system_rev < 130) { > arch/arm/mach-pxa/cm-x300.c: if (system_rev < 130) > arch/arm/mach-pxa/magician.c: if (system_rev < 3) > arch/arm/mach-pxa/magician.c: if (system_rev < 3) > arch/arm/mach-pxa/magician.c: system_rev = board_id & 0x7; > arch/arm/mach-pxa/magician.c: if (lcd_select && (system_rev < 3)) > arch/arm/mach-pxa/raumfeld.c: if ((system_rev & 0xff) == 2) { > arch/arm/mach-pxa/raumfeld.c: if ((system_rev & 0xff) > 1) { > arch/arm/mach-pxa/viper.c: system_rev = (VIPER_BOARD_VERSION(version) << 8) | > arch/arm/mach-pxa/zeus.c: system_rev = __raw_readw(ZEUS_CPLD_VERSION); > arch/arm/mach-pxa/zeus.c: pr_info("Zeus CPLD V%dI%d\n", (system_rev & 0xf0) >> 4, (system_rev & 0x0f)); > arch/arm/mach-zynq/common.c: system_rev = zynq_get_revision(); > arch/arm/mach-zynq/common.c: soc_dev_attr->revision = kasprintf(GFP_KERNEL, "0x%x", system_rev); > > In fact, half the uses of this actually assign the revision number themselves. > code outside of arch/arm/mach-* and /proc/cpuinfo currently uses the variable. > > Arnd -- Pali Rohár pali.rohar@gmail.com -- 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/