Hi Leif,
> -----Original Message-----
> From: Leif Lindholm <leif.lindh...@linaro.org>
> Sent: Thursday, November 8, 2018 10:00 AM
> To: Chris Co <christopher...@microsoft.com>
> Cc: edk2-devel@lists.01.org; Ard Biesheuvel <ard.biesheu...@linaro.org>;
> Michael D Kinney <michael.d.kin...@intel.com>
> Subject: Re: [PATCH edk2-platforms 12/27] Silicon/NXP: Add i.MX6 I/O MUX
> library
>
> On Fri, Sep 21, 2018 at 08:26:03AM +0000, Chris Co wrote:
> > This adds support for initializing and manipulating the I/O Pads on
> > NXP i.MX6 SoCs.
> >
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Christopher Co <christopher...@microsoft.com>
> > Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
> > Cc: Leif Lindholm <leif.lindh...@linaro.org>
> > Cc: Michael D Kinney <michael.d.kin...@intel.com>
> > ---
> > Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMux.c | 151
> ++++++++++++++++++++
> > Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMuxLib.inf | 41
> > ++++++
> > 2 files changed, 192 insertions(+)
> >
> > diff --git a/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMux.c
> > b/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMux.c
> > new file mode 100644
> > index 000000000000..7c0c7b54a2fe
> > --- /dev/null
> > +++ b/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMux.c
> > @@ -0,0 +1,151 @@
> > +/** @file
> > +*
> > +* Copyright (c) 2018 Microsoft Corporation. All rights reserved.
> > +*
> > +* This program and the accompanying materials
> > +* are licensed and made available under the terms and conditions of
> > +the BSD License
> > +* which accompanies this distribution. The full text of the license
> > +may be found at
> > +*
> > +https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fopens
> > +ource.org%2Flicenses%2Fbsd-
> license.php&data=02%7C01%7CChristopher
> >
> +.Co%40microsoft.com%7C416f86ef76c04f1cac6408d645a40e53%7C72f988b
> f86f1
> >
> +41af91ab2d7cd011db47%7C1%7C0%7C636772968261577670&sdata=
> vkaVmLhCg
> > +d0X80xpryCJ4kHPUTUtcv6W6MFg3a082nk%3D&reserved=0
> > +*
> > +* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
> > +BASIS,
> > +* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
> EXPRESS OR IMPLIED.
> > +*
> > +**/
> > +
> > +#include <PiDxe.h>
> > +
> > +#include <Library/DebugLib.h>
> > +#include <Library/IoLib.h>
> > +
> > +#include <iMX6.h>
> > +#include <iMX6IoMux.h>
> > +
> > +// Muxing functions
> > +VOID
> > +ImxPadConfig (
> > + IN IMX_PAD Pad,
> > + IN IMX_PADCFG PadConfig
>
> I'll get back to reviewing patch 11 at some point, but that one is hard
> going. So
> I'll point out here what I'll mention then:
> Please just use UINT64. Typedefs are useful to reduce pointless repetition for
> structs, but here it just obscures what is programatically going on.
>
I'm thinking to rework the PADCFG to actually use structs properly instead of
custom-packing with macros. It seems the previous dev was very macro happy and
I am the opposite...
The remaining feedback makes sense. Will address for v2.
Thanks,
Chris
> > + )
> > +{
> > + // Configure Mux Control
> > + MmioWrite32 (
> > + IMX_IOMUXC_BASE + _IMX_PAD_MUX_OFFSET (Pad),
> > + _IMX_PADCFG_MUX_CTL (PadConfig));
>
> It would be worth adding macros or simple accessor functions for these -
> there's
> a lot of text in this file that has no semantic value and needs to be manually
> filtered when reading.
>
> I.e. IomuxWrite32 (Pad, ...), IomuxRead32 (Pad), ...
>
> Other comment really belonging to 11:
> Please drop leading _ from macros. Such macros are intended for internal use
> by toolchains.
>
> > +
> > + // Configure Select Input Control
> > + if (_IMX_PADCFG_SEL_INP (PadConfig) != 0) {
> > + DEBUG ((DEBUG_INFO, "Setting INPUT_SELECT %x value %x\n",
> > + _IMX_SEL_INP_REGISTER (_IMX_PADCFG_SEL_INP (PadConfig)),
> > + _IMX_SEL_INP_VALUE (_IMX_PADCFG_SEL_INP (PadConfig))));
> > +
> > + MmioWrite32 (
> > + _IMX_SEL_INP_REGISTER (_IMX_PADCFG_SEL_INP (PadConfig)),
> > + _IMX_SEL_INP_VALUE (_IMX_PADCFG_SEL_INP (PadConfig))); }
> > +
> > + // Configure Pad Control
> > + MmioWrite32 (
> > + IMX_IOMUXC_BASE + _IMX_PAD_CTL_OFFSET (Pad),
> > + _IMX_PADCFG_PAD_CTL (PadConfig)); }
> > +
> > +VOID
> > +ImxPadDumpConfig (
> > + IN CHAR8 *SignalFriendlyName,
> > + IN IMX_PAD Pad
> > + )
> > +{
> > + IMX_IOMUXC_MUX_CTL MuxCtl;
> > + IMX_IOMUXC_PAD_CTL PadCtl;
> > +
> > + MuxCtl.AsUint32 = MmioRead32 (
> > + IMX_IOMUXC_BASE + _IMX_PAD_MUX_OFFSET (Pad));
> > +
> > + DEBUG ((
> > + DEBUG_INIT,
> > + "- %a MUX_CTL(0x%p)=0x%08x: MUX_MODE:%d SION:%d | ",
> > + SignalFriendlyName,
> > + IMX_IOMUXC_BASE + _IMX_PAD_MUX_OFFSET (Pad),
> > + MuxCtl.AsUint32,
> > + MuxCtl.Fields.MUX_MODE,
> > + MuxCtl.Fields.SION));
> > +
> > + PadCtl.AsUint32 = MmioRead32 (
> > + IMX_IOMUXC_BASE + _IMX_PAD_CTL_OFFSET (Pad));
> > +
> > + DEBUG ((
> > + DEBUG_INIT,
> > + "PAD_CTL(0x%p)=0x%08x: SRE:%d DSE:%d SPEED:%d ODE:%d PKE:%d
> PUE:%d PUS:%d HYS:%d\n",
> > + IMX_IOMUXC_BASE + _IMX_PAD_CTL_OFFSET (Pad),
> > + PadCtl.AsUint32,
> > + PadCtl.Fields.SRE,
> > + PadCtl.Fields.DSE,
> > + PadCtl.Fields.SPEED,
> > + PadCtl.Fields.ODE,
> > + PadCtl.Fields.PKE,
> > + PadCtl.Fields.PUE,
> > + PadCtl.Fields.PUS,
> > + PadCtl.Fields.HYS));
> > +}
> > +
> > +// GPIO functions
> > +VOID
> > +ImxGpioDirection (
> > + IN IMX_GPIO_BANK Bank,
> > + IN UINT32 IoNumber,
> > + IN IMX_GPIO_DIR Direction
> > + )
> > +{
> > + volatile IMX_GPIO_REGISTERS *gpioRegisters;
>
> What makes this pointer volatile?
> (Hint: drop it, it does nothing useful here.)
>
> That initial 'g', following EDK2 naming rules, says that this is a variable
> in the
> global namespace, exported from this module. It should be GpioRegisters.
>
> > +
> > + ASSERT (IoNumber < 32);
>
> That 32 needs a #define.
>
> > +
> > + gpioRegisters = (IMX_GPIO_REGISTERS *) IMX_GPIO_BASE; if
> > + (Direction == IMX_GPIO_DIR_INPUT) {
> > + MmioAnd32 ((UINTN) &gpioRegisters->Banks[Bank - 1].GDIR, ~ (1 <<
> > + IoNumber));
>
> This 'Bank - 1' stuff looks a bit scary. Why aren't we passing the inde to
> use? A
> comment block before the function could explain what the inputs are meant to
> be.
>
> > + } else {
> > + MmioOr32 ((UINTN) &gpioRegisters->Banks[Bank - 1].GDIR, 1 <<
> > + IoNumber);
>
> Since we're doing 1 << IoNumber on all possible routes through this function,
> could we assign it to a temporary variable? And we're doing it to the same
> bank.
>
> If I wrote this function, I'd probably do something more like
>
> UINTN DirectionRegister;
> UINT32 Pin;
> DirectionRegister = (UINTN)&((IMX_GPIO_REGISTERS *)IMX_GPIO_BASE)-
> >Banks[Bank - 1].GDIR;
> Pin = 1 << IoNumber;
>
> if (Direction == IMX_GPIO_DIR_INPUT) {
> MmioAnd32 (DirectionRegister, ~Pin);
> } else {
> MmioOr32 (DirectionRegister, Pin);
> }
>
> > + }
> > +}
> > +
> > +VOID
> > +ImxGpioWrite (
> > + IN IMX_GPIO_BANK Bank,
> > + IN UINT32 IoNumber,
> > + IN IMX_GPIO_VALUE Value
> > + )
> > +{
> > + volatile IMX_GPIO_REGISTERS *gpioRegisters;
> > +
> > + ASSERT (IoNumber < 32);
> > +
> > + gpioRegisters = (IMX_GPIO_REGISTERS *) IMX_GPIO_BASE; if (Value ==
> > + IMX_GPIO_LOW) {
> > + MmioAnd32 ((UINTN) &gpioRegisters->Banks[Bank - 1].DR, ~ (1 <<
> > + IoNumber)); } else {
> > + MmioOr32 ((UINTN) &gpioRegisters->Banks[Bank - 1].DR, 1 <<
> > + IoNumber); }
>
> All the same comments as above.
>
> > +}
> > +
> > +IMX_GPIO_VALUE
> > +ImxGpioRead (
> > + IN IMX_GPIO_BANK Bank,
> > + IN UINT32 IoNumber
> > + )
> > +{
> > + volatile IMX_GPIO_REGISTERS *gpioRegisters;
> > + UINT32 Mask;
> > + UINT32 Psr;
> > +
> > + ASSERT (IoNumber < 32);
> > +
> > + gpioRegisters = (IMX_GPIO_REGISTERS *) IMX_GPIO_BASE; Mask = (1 <<
> > + IoNumber); Psr = MmioRead32 ((UINTN) &gpioRegisters->Banks[Bank -
> > + 1].PSR);
> > +
> > + if (Psr & Mask) {
> > + return IMX_GPIO_HIGH;
> > + } else {
> > + return IMX_GPIO_LOW;
> > + }
>
> Some of the same comments as above :)
> (I.e., those that apply.)
>
> /
> Leif
>
> > +}
> > diff --git a/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMuxLib.inf
> > b/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMuxLib.inf
> > new file mode 100644
> > index 000000000000..84bbbee5c1db
> > --- /dev/null
> > +++ b/Silicon/NXP/iMX6Pkg/Library/iMX6IoMuxLib/iMX6IoMuxLib.inf
> > @@ -0,0 +1,41 @@
> > +## @file
> > +#
> > +# Copyright (c) 2018 Microsoft Corporation. All rights reserved.
> > +#
> > +# This program and the accompanying materials # are licensed and
> > +made available under the terms and conditions of the BSD License #
> > +which accompanies this distribution. The full text of the license
> > +may be found at #
> > +https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fopens
> > +ource.org%2Flicenses%2Fbsd-
> license.php&data=02%7C01%7CChristopher
> >
> +.Co%40microsoft.com%7C416f86ef76c04f1cac6408d645a40e53%7C72f988b
> f86f1
> >
> +41af91ab2d7cd011db47%7C1%7C0%7C636772968261577670&sdata=
> vkaVmLhCg
> > +d0X80xpryCJ4kHPUTUtcv6W6MFg3a082nk%3D&reserved=0
> > +#
> > +# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
> > +BASIS, # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND,
> EITHER EXPRESS OR IMPLIED.
> > +#
> > +##
> > +
> > +[Defines]
> > + INF_VERSION = 0x0001001A
> > + BASE_NAME = iMX6IoMuxLib
> > + FILE_GUID = FA41BEF0-0666-4C07-9EC3-47F61C36EDBE
> > + MODULE_TYPE = BASE
> > + VERSION_STRING = 1.0
> > + LIBRARY_CLASS = iMX6IoMuxLib
> > +
> > +[Packages]
> > + ArmPkg/ArmPkg.dec
> > + EmbeddedPkg/EmbeddedPkg.dec
> > + MdeModulePkg/MdeModulePkg.dec
> > + MdePkg/MdePkg.dec
> > + Silicon/NXP/iMX6Pkg/iMX6Pkg.dec
> > + Silicon/NXP/iMXPlatformPkg/iMXPlatformPkg.dec
> > +
> > +[LibraryClasses]
> > + BaseMemoryLib
> > + DebugLib
> > + IoLib
> > + TimerLib
> > +
> > +[Sources.common]
> > + iMX6IoMux.c
> > +
> > + [FixedPcd]
> > + giMXPlatformTokenSpaceGuid.PcdGpioBankMemoryRange
> > --
> > 2.16.2.gvfs.1.33.gf5370f1
> >
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