| Message ID | 1399938570-11356-5-git-send-email-matthias.bgg@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/13, Matthias Brugger wrote: > diff --git a/arch/arm/mach-mediatek/mediatek.c b/arch/arm/mach-mediatek/mediatek.c > new file mode 100644 > index 0000000..73dfb05 > --- /dev/null > +++ b/arch/arm/mach-mediatek/mediatek.c > @@ -0,0 +1,32 @@ > +/* > + * Device Tree support for Mediatek SoCs > + * > + * Copyright (c) 2014 MundoReader S.L. > + * Author: Matthias Brugger <matthias.bgg@gmail.com> > + * > + * 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. > + */ > + > +#include <linux/kernel.h> > +#include <linux/init.h> > +#include <linux/of_platform.h> > +#include <linux/irqchip.h> > +#include <asm/mach/arch.h> > +#include <asm/mach/map.h> > + > +static const char * const mediatek_board_dt_compat[] = { __initconst? > + "mediatek,mt6589", > + NULL, > +}; > + > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") > + .dt_compat = mediatek_board_dt_compat, > +MACHINE_END You shouldn't need this file at all if the platform is part of the multi-platform kernel.
Hi Stephen, On Tue, May 13, 2014 at 03:47:32PM -0700, Stephen Boyd wrote: > On 05/13, Matthias Brugger wrote: > > diff --git a/arch/arm/mach-mediatek/mediatek.c b/arch/arm/mach-mediatek/mediatek.c > > new file mode 100644 > > index 0000000..73dfb05 > > --- /dev/null > > +++ b/arch/arm/mach-mediatek/mediatek.c > > @@ -0,0 +1,32 @@ > > +/* > > + * Device Tree support for Mediatek SoCs > > + * > > + * Copyright (c) 2014 MundoReader S.L. > > + * Author: Matthias Brugger <matthias.bgg@gmail.com> > > + * > > + * 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. > > + */ > > + > > +#include <linux/kernel.h> > > +#include <linux/init.h> > > +#include <linux/of_platform.h> > > +#include <linux/irqchip.h> > > +#include <asm/mach/arch.h> > > +#include <asm/mach/map.h> > > + > > +static const char * const mediatek_board_dt_compat[] = { > > __initconst? > > > + "mediatek,mt6589", > > + NULL, > > +}; > > + > > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") > > + .dt_compat = mediatek_board_dt_compat, > > +MACHINE_END > > You shouldn't need this file at all if the platform is part of > the multi-platform kernel. From a technical point of view, you don't. But it's interesting to keep it mostly for two things: - You get to see the platform name in /proc/cpuinfo - If you ever need to add platform quirks, it's already there We had a similar discussion two weeks ago for mach-sunxi with Olof and Arnd, and ended up keeping this minimal machine. Maxime
On 05/14, Maxime Ripard wrote: > On Tue, May 13, 2014 at 03:47:32PM -0700, Stephen Boyd wrote: > > On 05/13, Matthias Brugger wrote: > > > + "mediatek,mt6589", > > > + NULL, > > > +}; > > > + > > > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") > > > + .dt_compat = mediatek_board_dt_compat, > > > +MACHINE_END > > > > You shouldn't need this file at all if the platform is part of > > the multi-platform kernel. > > From a technical point of view, you don't. But it's interesting to > keep it mostly for two things: > - You get to see the platform name in /proc/cpuinfo > - If you ever need to add platform quirks, it's already there > > We had a similar discussion two weeks ago for mach-sunxi with Olof and > Arnd, and ended up keeping this minimal machine. > It looks like it's only useful to make /proc/cpuinfo have the platform name because it really isn't that hard to add this file if we need to add platform quirks. The downside is we have to keep adding compatibles when we support new SoCs. This all leads back to the patch from Rob that removes the .name field from the DT based machine descriptor[1]. I'm not sure that thread ever resolved but it looked like a step in the right direction. At least it matches what arm64 (and what looks like mips) are doing. The concern there was finding which machine descriptor was used for the init path. Perhaps we should only use of_flat_dt_get_machine_name() for the generic machine descriptor so platforms that are using their own machine descriptor get their .name field printed and they know that their descriptor was used (assuming the .name field is unique) but the platforms using the generic descriptor would get more meaningful information and we wouldn't need to have these skeleton machine descriptors. [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/277536
On Wednesday 14 May 2014 14:26:12 Stephen Boyd wrote: > On 05/14, Maxime Ripard wrote: > > On Tue, May 13, 2014 at 03:47:32PM -0700, Stephen Boyd wrote: > > > On 05/13, Matthias Brugger wrote: > > > > + "mediatek,mt6589", > > > > + NULL, > > > > +}; > > > > + > > > > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") > > > > + .dt_compat = mediatek_board_dt_compat, > > > > +MACHINE_END > > > > > > You shouldn't need this file at all if the platform is part of > > > the multi-platform kernel. > > > > From a technical point of view, you don't. But it's interesting to > > keep it mostly for two things: > > - You get to see the platform name in /proc/cpuinfo > > - If you ever need to add platform quirks, it's already there > > > > We had a similar discussion two weeks ago for mach-sunxi with Olof and > > Arnd, and ended up keeping this minimal machine. > > > > It looks like it's only useful to make /proc/cpuinfo have the > platform name because it really isn't that hard to add this file > if we need to add platform quirks. The downside is we have to > keep adding compatibles when we support new SoCs. We also still add Kconfig entries for each new platform, and I'd like to leave it at that for the time being. In a lot of cases we end up adding stuff to the machine descriptor later, e.g. for SMP support (hopefully no more thanks to your work though). Once we have a significant number of machines that are actually usable rather than stubs and that we are confident about never needing any additional pointers, we can revisit this discussion. At that point, we should also discuss how to avoid adding a Kconfig entry for each new platform, which e.g. involves making the clocksource drivers user selectable. That part has been surprisingly controversial in the past. Arnd
On Wed, May 14, 2014 at 2:00 AM, Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > Hi Stephen, > > On Tue, May 13, 2014 at 03:47:32PM -0700, Stephen Boyd wrote: >> On 05/13, Matthias Brugger wrote: >> > diff --git a/arch/arm/mach-mediatek/mediatek.c b/arch/arm/mach-mediatek/mediatek.c >> > new file mode 100644 >> > index 0000000..73dfb05 >> > --- /dev/null >> > +++ b/arch/arm/mach-mediatek/mediatek.c >> > @@ -0,0 +1,32 @@ >> > +/* >> > + * Device Tree support for Mediatek SoCs >> > + * >> > + * Copyright (c) 2014 MundoReader S.L. >> > + * Author: Matthias Brugger <matthias.bgg@gmail.com> >> > + * >> > + * 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. >> > + */ >> > + >> > +#include <linux/kernel.h> >> > +#include <linux/init.h> >> > +#include <linux/of_platform.h> >> > +#include <linux/irqchip.h> >> > +#include <asm/mach/arch.h> >> > +#include <asm/mach/map.h> >> > + >> > +static const char * const mediatek_board_dt_compat[] = { >> >> __initconst? >> >> > + "mediatek,mt6589", >> > + NULL, >> > +}; >> > + >> > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") >> > + .dt_compat = mediatek_board_dt_compat, >> > +MACHINE_END >> >> You shouldn't need this file at all if the platform is part of >> the multi-platform kernel. > > From a technical point of view, you don't. But it's interesting to > keep it mostly for two things: > - You get to see the platform name in /proc/cpuinfo We should be getting this string from model or top-level compatible string in the dtb. I did a patch to do just this [1], but people did not like removing this string. We should really decide if getting rid of machine descriptors is a goal or not. We should at least make things such that the cpuinfo string does not change on new platforms based on whether they have a machine desc or not. > - If you ever need to add platform quirks, it's already there That is a weak argument when usually we add things as they are needed. Rob [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/208878.html
On Thu, May 15, 2014 at 2:58 AM, Arnd Bergmann <arnd@arndb.de> wrote: > On Wednesday 14 May 2014 14:26:12 Stephen Boyd wrote: >> On 05/14, Maxime Ripard wrote: >> > On Tue, May 13, 2014 at 03:47:32PM -0700, Stephen Boyd wrote: >> > > On 05/13, Matthias Brugger wrote: >> > > > + "mediatek,mt6589", >> > > > + NULL, >> > > > +}; >> > > > + >> > > > +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") >> > > > + .dt_compat = mediatek_board_dt_compat, >> > > > +MACHINE_END >> > > >> > > You shouldn't need this file at all if the platform is part of >> > > the multi-platform kernel. >> > >> > From a technical point of view, you don't. But it's interesting to >> > keep it mostly for two things: >> > - You get to see the platform name in /proc/cpuinfo >> > - If you ever need to add platform quirks, it's already there >> > >> > We had a similar discussion two weeks ago for mach-sunxi with Olof and >> > Arnd, and ended up keeping this minimal machine. >> > >> >> It looks like it's only useful to make /proc/cpuinfo have the >> platform name because it really isn't that hard to add this file >> if we need to add platform quirks. The downside is we have to >> keep adding compatibles when we support new SoCs. > > We also still add Kconfig entries for each new platform, and I'd like > to leave it at that for the time being. In a lot of cases we end > up adding stuff to the machine descriptor later, e.g. for SMP support > (hopefully no more thanks to your work though). > > Once we have a significant number of machines that are actually > usable rather than stubs and that we are confident about never > needing any additional pointers, we can revisit this discussion. > > At that point, we should also discuss how to avoid adding a Kconfig > entry for each new platform, which e.g. involves making the > clocksource drivers user selectable. That part has been surprisingly > controversial in the past. The kconfig part doesn't really worry me. The cpuinfo string is something we should decide now because it leaks to userspace. There are 3 possible positions I can think of: 1) The name is part of the ABI and we can never remove/change the string. 2) The name is not an ABI and either: a) we don't care if it changes with matching a machine desc or not. b) we still want it to be consistent independent of matching 2a is what we have today. I'm in favor of 2b and therefore should get the name from DT. It is similar to names in /sys/bus/platform/ which are not considered part of the ABI. The string already changed moving platforms to DT and that did not seem to cause any issues that I heard of. Rob
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index db3c541..0fc8acd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -997,6 +997,8 @@ source "arch/arm/mach-mv78xx0/Kconfig" source "arch/arm/mach-imx/Kconfig" +source "arch/arm/mach-mediatek/Kconfig" + source "arch/arm/mach-mxs/Kconfig" source "arch/arm/mach-netx/Kconfig" diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 41c1931..8ce9774 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -170,6 +170,7 @@ machine-$(CONFIG_ARCH_MSM) += msm machine-$(CONFIG_ARCH_MV78XX0) += mv78xx0 machine-$(CONFIG_ARCH_MVEBU) += mvebu machine-$(CONFIG_ARCH_MXC) += imx +machine-$(CONFIG_ARCH_MEDIATEK) += mediatek machine-$(CONFIG_ARCH_MXS) += mxs machine-$(CONFIG_ARCH_NETX) += netx machine-$(CONFIG_ARCH_NOMADIK) += nomadik diff --git a/arch/arm/boot/dts/mt6589.dtsi b/arch/arm/boot/dts/mt6589.dtsi new file mode 100644 index 0000000..ab554e8 --- /dev/null +++ b/arch/arm/boot/dts/mt6589.dtsi @@ -0,0 +1,93 @@ +/* + * Copyright (c) 2014 MundoReader S.L. + * Author: Matthias Brugger <matthias.bgg@gmail.com> + * + * 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. + */ + +#include <dt-bindings/interrupt-controller/irq.h> +#include <dt-bindings/interrupt-controller/arm-gic.h> +#include "skeleton.dtsi" + +/ { + compatible = "mediatek,mt6589"; + interrupt-parent = <&gic>; + + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x0>; + }; + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x1>; + }; + cpu@2 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x2>; + }; + cpu@3 { + device_type = "cpu"; + compatible = "arm,cortex-a7"; + reg = <0x3>; + }; + + }; + + clocks { + #address-cells = <1>; + #size-cells = <1>; + ranges; + + dummy13m: dummy13m { + compatible = "fixed-clock"; + clock-frequency = <13000000>; + #clock-cells = <0>; + }; + + dummy32k: dummy32k { + compatible = "fixed-clock"; + clock-frequency = <32000>; + #clock-cells = <0>; + }; + }; + + soc { + #address-cells = <1>; + #size-cells = <1>; + compatible = "simple-bus"; + clock-ranges; + ranges; + + timer: timer@10008000 { + compatible = "mediatek,mtk6589-timer"; + reg = <0x10008000 0x80>; + interrupts = <GIC_SPI 113 IRQ_TYPE_EDGE_RISING>; + clocks = <&dummy13m>, <&dummy32k>; + }; + + gic: interrupt-controller@10212000 { + compatible = "arm,cortex-a15-gic"; + interrupt-controller; + #interrupt-cells = <3>; + reg = <0x10211000 0x1000>, + <0x10212000 0x1000>, + <0x10214000 0x2000>, + <0x10216000 0x2000>; + }; + }; +}; diff --git a/arch/arm/mach-mediatek/Kconfig b/arch/arm/mach-mediatek/Kconfig new file mode 100644 index 0000000..2c043a2 --- /dev/null +++ b/arch/arm/mach-mediatek/Kconfig @@ -0,0 +1,6 @@ +config ARCH_MEDIATEK + bool "Mediatek MT6589 SoC" if ARCH_MULTI_V7 + select ARM_GIC + select MTK_TIMER + help + Support for Mediatek Cortex-A7 Quad-Core-SoC MT6589. diff --git a/arch/arm/mach-mediatek/Makefile b/arch/arm/mach-mediatek/Makefile new file mode 100644 index 0000000..43e619f --- /dev/null +++ b/arch/arm/mach-mediatek/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_ARCH_MEDIATEK) += mediatek.o diff --git a/arch/arm/mach-mediatek/mediatek.c b/arch/arm/mach-mediatek/mediatek.c new file mode 100644 index 0000000..73dfb05 --- /dev/null +++ b/arch/arm/mach-mediatek/mediatek.c @@ -0,0 +1,32 @@ +/* + * Device Tree support for Mediatek SoCs + * + * Copyright (c) 2014 MundoReader S.L. + * Author: Matthias Brugger <matthias.bgg@gmail.com> + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/of_platform.h> +#include <linux/irqchip.h> +#include <asm/mach/arch.h> +#include <asm/mach/map.h> + +static const char * const mediatek_board_dt_compat[] = { + "mediatek,mt6589", + NULL, +}; + +DT_MACHINE_START(MEDIATEK_DT, "Mediatek Cortex-A7 (Device Tree)") + .dt_compat = mediatek_board_dt_compat, +MACHINE_END
This adds a generic devicetree board file and a dtsi for boards based on MT6589 SoCs from Mediatek. Apart from the generic parts (gic, clocks) the only component currently supported are the timers. Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com> --- arch/arm/Kconfig | 2 + arch/arm/Makefile | 1 + arch/arm/boot/dts/mt6589.dtsi | 93 +++++++++++++++++++++++++++++++++++++++ arch/arm/mach-mediatek/Kconfig | 6 +++ arch/arm/mach-mediatek/Makefile | 1 + arch/arm/mach-mediatek/mediatek.c | 32 ++++++++++++++ 6 files changed, 135 insertions(+) create mode 100644 arch/arm/boot/dts/mt6589.dtsi create mode 100644 arch/arm/mach-mediatek/Kconfig create mode 100644 arch/arm/mach-mediatek/Makefile create mode 100644 arch/arm/mach-mediatek/mediatek.c