Re: [PATCH v2 1/2] OMAP: Zoom2: Add DEBUG_LL interface using Quart

[Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>]

Pandita, Vikram wrote:
> > -----Original Message-----
> > From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx]
> >
> > > This patch adds DEBUG_LL interface for Zoom2 board.
> > > The low level debug uart now points corrctly to External Quad uart
> > > controller on detachable debug board.
> > >
> > > The Quad uart is available over GPMC chip select with physical address
> > > 0x10000000.
> > >
> > > This physical address has been mapped to virtual address 0xFB000000
> > > as per static mapping.
> > I see you dropped the UPF_IOREMAP flag. Why do we need a static
> > mapping here?  The early access will be taken care of by the .phys_io
> > field of the mach_desc, no?
>
> Step 1:
> The first early mapping happens with phys_io. Just for debug uart access.
> Step 2:
> This is over-written by mapping done by omap2_map_common_io -> iotable_init
>
> I removed the flag UPF_IOREMAP for the serial 8250 driver.
> If UPF_IOREMAP flag is given, then serial driver will do yet one more mapping, 
> which is already done by step 2.
>
> Hence the flag is no longer needed for serial port mapping.

OK, thanks for clarifying.  After reviewing your DEBUG_LL rework, I also 
notice that it requires a static mapping too.

Kevin

> > Kevin
> >
> > > This patch is adapted from a version by Erik Gilling:
> > > http://android.git.kernel.org/?p=kernel/omap.git;
> > > a=commit;h=e9d72efdd88877d2d6ea74a08983ace0dcc771d3
> > >
> > > Signed-off-by: Vikram Pandita <vikram.pandita@xxxxxx>
> > > Cc: Erik Gilling <konkers@xxxxxxxxxxx>
> > > ---
> > >  arch/arm/mach-omap2/board-zoom-debugboard.c |    5 +++--
> > >  arch/arm/mach-omap2/board-zoom2.c           |   19 +++++++++++++++++--
> > >  arch/arm/plat-omap/include/mach/io.h        |    6 ++++++
> > >  3 files changed, 26 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/arch/arm/mach-omap2/board-zoom-debugboard.c b/arch/arm/mach-omap2/board-zoom-
> > debugboard.c
> > > index 1f13e2a..70a4bba 100644
> > > --- a/arch/arm/mach-omap2/board-zoom-debugboard.c
> > > +++ b/arch/arm/mach-omap2/board-zoom-debugboard.c
> > > @@ -82,9 +82,10 @@ static inline void __init zoom2_init_smsc911x(void)
> > >
> > >  static struct plat_serial8250_port serial_platform_data[] = {
> > >  	{
> > > -		.mapbase	= 0x10000000,
> > > +		.membase	= IOMEM(ZOOM2_EXT_QUART_VIRT),
> > > +		.mapbase	= ZOOM2_EXT_QUART_PHYS,
> > >  		.irq		= OMAP_GPIO_IRQ(102),
> > > -		.flags		= UPF_BOOT_AUTOCONF|UPF_IOREMAP|UPF_SHARE_IRQ,
> > > +		.flags		= UPF_BOOT_AUTOCONF|UPF_SHARE_IRQ,
> > >  		.irqflags	= IRQF_SHARED | IRQF_TRIGGER_RISING,
> > >  		.iotype		= UPIO_MEM,
> > >  		.regshift	= 1,
> > > diff --git a/arch/arm/mach-omap2/board-zoom2.c b/arch/arm/mach-omap2/board-zoom2.c
> > > index 324009e..467e961 100644
> > > --- a/arch/arm/mach-omap2/board-zoom2.c
> > > +++ b/arch/arm/mach-omap2/board-zoom2.c
> > > @@ -19,10 +19,12 @@
> > >
> > >  #include <asm/mach-types.h>
> > >  #include <asm/mach/arch.h>
> > > +#include <asm/mach/map.h>
> > >
> > >  #include <mach/common.h>
> > >  #include <mach/usb.h>
> > >  #include <mach/keypad.h>
> > > +#include <mach/uncompress.h>
> > >
> > >  #include "mmc-twl4030.h"
> > >
> > > @@ -269,15 +271,28 @@ static void __init omap_zoom2_init(void)
> > >  	usb_musb_init();
> > >  }
> > >
> > > +static struct map_desc zoom2_io_desc[] __initdata = {
> > > +	{
> > > +		.virtual	= ZOOM2_EXT_QUART_VIRT,
> > > +		.pfn		= __phys_to_pfn(ZOOM2_EXT_QUART_PHYS),
> > > +		.length		= ZOOM2_EXT_QUART_SIZE,
> > > +		.type		= MT_DEVICE
> > > +	}
> > > +};
> > > +
> > >  static void __init omap_zoom2_map_io(void)
> > >  {
> > >  	omap2_set_globals_343x();
> > > +
> > > +	/* Map external quad UART virt to phy mapping */
> > > +	iotable_init(zoom2_io_desc, ARRAY_SIZE(zoom2_io_desc));
> > > +
> > >  	omap2_map_common_io();
> > >  }
> > >
> > >  MACHINE_START(OMAP_ZOOM2, "OMAP Zoom2 board")
> > > -	.phys_io	= 0x48000000,
> > > -	.io_pg_offst	= ((0xd8000000) >> 18) & 0xfffc,
> > > +	.phys_io	= ZOOM2_EXT_QUART_PHYS,
> > > +	.io_pg_offst	= ((ZOOM2_EXT_QUART_VIRT) >> 18) & 0xfffc,
> > >  	.boot_params	= 0x80000100,
> > >  	.map_io		= omap_zoom2_map_io,
> > >  	.init_irq	= omap_zoom2_init_irq,
> > > diff --git a/arch/arm/plat-omap/include/mach/io.h b/arch/arm/plat-omap/include/mach/io.h
> > > index 8d32df3..d67f06c 100644
> > > --- a/arch/arm/plat-omap/include/mach/io.h
> > > +++ b/arch/arm/plat-omap/include/mach/io.h
> > > @@ -169,6 +169,12 @@
> > >  #define DSP_MMU_34XX_VIRT	0xe2000000
> > >  #define DSP_MMU_34XX_SIZE	SZ_4K
> > >
> > > +/* Map External Quad UART for Zoom2 board */
> > > +#define ZOOM2_EXT_QUART_PHYS		0x10000000 /* PHY address if fixed */
> > > +#define ZOOM2_EXT_QUART_PHY_TO_VIRT_OFF	0xEB000000
> > > +#define ZOOM2_EXT_QUART_VIRT		0xFB000000
> > > +#define ZOOM2_EXT_QUART_SIZE		SZ_16
> > > +
> > >  /*
> > >   * ----------------------------------------------------------------------------
> > >   * Omap4 specific IO mapping
> > > --
> > > 1.6.3.3.334.g916e1
> > >
> > > --
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