[PATCH] Add lvgl_hello: Sample Hello world app using littleVGL and libbsd

Vijay Kumar Banerjee vijaykumar9597 at gmail.com
Tue Sep 17 06:46:17 UTC 2019


On Thu, Sep 12, 2019 at 2:37 PM Christian Mauderer <
christian.mauderer at embedded-brains.de> wrote:

>
>
> On 12/09/2019 10:28, Vijay Kumar Banerjee wrote:
> >
> >
> >
> > On Wed, Sep 11, 2019 at 4:38 PM Christian Mauderer
> > <christian.mauderer at embedded-brains.de
> > <mailto:christian.mauderer at embedded-brains.de>> wrote:
> >
> >     On 11/09/2019 10:48, Vijay Kumar Banerjee wrote:
> >     >
> >     >  Hi,
> >     >
> >     > Since adding I2C in BBB initialization seems like the right
> solution,
> >     > should we ask
> >     > in devel and user lists in a separate thread, to know if anyone is
> >     > opposed to this change?
> >
> >     Hello Vijay,
> >
> >     just send a patch. That will start the discussion if someone objects
> >     to it.
> >
> >     >
> >     > Where should I be looking for to add i2c in BBB initialization?
> >
> >     Please take a look at the dependencies. If there are any (like
> clocks or
> >     similar) you have to add it afterwards.
> >
> >     Take a look at some other BSPs where similar hardware (like I2C, SPI,
> >     some external chips, ...) is initialized. For example the mvme3100
> uses
> >     a RTEMS_SYSINIT_ITEM to pick a random sample. But I think most BSPs
> use
> >     a special init function similar to the one in BBB.
> >
> > Hi,
> >
> > I tried a very similar approach and added RTEMS_SYSINIT_ITEM
> > :
> > ```
> > diff --git a/bsps/arm/beagle/start/bspstart.c
> > b/bsps/arm/beagle/start/bspstart.c
> > index 224f9ecf3b..35839e774b 100644
> > --- a/bsps/arm/beagle/start/bspstart.c
> > +++ b/bsps/arm/beagle/start/bspstart.c
> > @@ -17,6 +17,8 @@
> >  #include <bsp/irq-generic.h>
> >  #include <bsp/fdt.h>
> >  #include <bsp/linker-symbols.h>
> > +#include <bsp/i2c.h>
> > +#include <rtems/sysinit.h>
> >
> >  #include "bspdebug.h"
> >
> > @@ -41,3 +43,15 @@ uint32_t bsp_fdt_map_intr(const uint32_t *intr,
> > size_t icells)
> >  {
> >    return intr[0];
> >  }
> > +
> > +static void bbb_i2c_0_initialize(void)
> > +{
> > +  bbb_register_i2c_0();
> > +}
> > +
> > +RTEMS_SYSINIT_ITEM(
> > +  bbb_i2c_0_initialize,
> > +  RTEMS_SYSINIT_BSP_PRE_DRIVERS,
> > +  RTEMS_SYSINIT_ORDER_MIDDLE
> > +);
> > ```
> > This is successfully calling the `am335x_i2c_bus_register` but
> > the issue with this approach is that it's returning the following
> > internal error after `am335x_i2c_reset` call.
> > ```
> > _Terminate (the_source=the_source at entry=INTERNAL_ERROR_CORE,
> > the_error=the_error at entry=30)
> > ```
> >
> > Any hint on what might be the cause of the error?
>
> Just a guess: Are you sure that "BSP_PRE_DRIVERS" is the right order?
> It's a driver so maybe somewhen during the drivers?
>
> I tried RTEMS_SYSINIT_DEVICE_DRIVERS, and eve RTEMS_SYSINIT_LAST,
but it doesn't seem to work. Maybe it needs to be called in a further later
stage.

> Does bbb_i2c_0_initialize has a type that is compatible with the sysinit
> items?
>
> yes, I checked this. the function is called and it's reaching am335x_i2c_*
calls
but it's getting stuck somewhere between i2c_reset and pinmux. Am I possibly
missing some other drivers that it depends on?
Can you please point me to the doc/note where the init sequence is properly
described. Also, if there's some other bsp that has initialized a driver at
init, please
point me to that for reference.

> >
> >     Best regards
> >
> >     Christian
> >
>
> --
> --------------------------------------------
> embedded brains GmbH
> Herr Christian Mauderer
> Dornierstr. 4
> D-82178 Puchheim
> Germany
> email: christian.mauderer at embedded-brains.de
> Phone: +49-89-18 94 741 - 18
> Fax:   +49-89-18 94 741 - 08
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>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
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