[PATCH v2] bsps/beagle: register i2c device at initialization

[Vijay Kumar Banerjee]

On Thu, Sep 19, 2019 at 10:05 PM Christian Mauderer <list at c-mauderer.de>
wrote:

> Hello Vijay,
>
> sorry for being picky: What happens if something goes wrong during that
> initialization? For example: If the system has a configuration where
> /dev/i2c0 can't be created. In that case it will just silently fail to
> create the i2c-0 which maybe leads to odd errors later.
>
> This is a very good point.

> There's already one precedent case how that could be handled: The
> powerpc/mvme3100 BSP. That BSP also initializes an I2C driver with a
> RTEMS_SYSINIT_ITEM. The return value is ignored too. But the
> BSP_i2c_initialize does print error messages.
>
> I would suggest that here too: Check the return value of
> am335x_i2c_bus_register in your new bbb_i2c_0_initialize and at least
> print an error message that i2c0 couldn't be initialized. Most likely
> you should use printk here because it's not sure whether printf would
> work already.
>
> Will it be sufficient to do this:
```
static void bbb_i2c_0_initialize(void)
{
  int err;

  err = am335x_i2c_bus_register(BBB_I2C_0_BUS_PATH,
                                AM335X_I2C0_BASE,
                                I2C_BUS_CLOCK_DEFAULT,
                                BBB_I2C0_IRQ);
  if (err != 0){
    printk("i2c-0 device could not be registered");
  }
}
```

> Best regards
>
> Christian
>
> On 18/09/2019 21:18, Vijay Kumar Banerjee wrote:
> > ---
> >  bsps/arm/beagle/i2c/bbb-i2c.c     |  6 +++---
> >  bsps/arm/beagle/include/bsp/i2c.h | 10 ----------
> >  bsps/arm/beagle/start/bspstart.c  | 16 ++++++++++++++++
> >  3 files changed, 19 insertions(+), 13 deletions(-)
> >
> > diff --git a/bsps/arm/beagle/i2c/bbb-i2c.c
> b/bsps/arm/beagle/i2c/bbb-i2c.c
> > index 37b88864b9..f705078085 100644
> > --- a/bsps/arm/beagle/i2c/bbb-i2c.c
> > +++ b/bsps/arm/beagle/i2c/bbb-i2c.c
> > @@ -186,16 +186,16 @@ static int am335x_i2c_reset( bbb_i2c_bus *bus )
> >
> >    bus->con_reg = 0;
> >    regs->BBB_I2C_CON = bus->con_reg;
> > -  udelay( 50000 );
> > +  rtems_counter_delay_nanoseconds(50000000);
> >
> >    regs->BBB_I2C_SYSC = AM335X_I2C_SYSC_SRST;
> > -  udelay( 1000 );
> > +  rtems_counter_delay_nanoseconds(1000000);
> >    regs->BBB_I2C_CON = AM335X_I2C_CON_I2C_EN;
> >
> >    while ( !( regs->BBB_I2C_SYSS & AM335X_I2C_SYSS_RDONE )
> >            && timeout >= 0 ) {
> >      --timeout;
> > -    udelay( 100 );
> > +  rtems_counter_delay_nanoseconds(100000);
> >    }
> >
> >    if ( timeout <= 0 ) {
> > diff --git a/bsps/arm/beagle/include/bsp/i2c.h
> b/bsps/arm/beagle/include/bsp/i2c.h
> > index 9d253406bf..60f71194bf 100644
> > --- a/bsps/arm/beagle/include/bsp/i2c.h
> > +++ b/bsps/arm/beagle/include/bsp/i2c.h
> > @@ -94,16 +94,6 @@ int am335x_i2c_bus_register(
> >    rtems_vector_number irq
> >  );
> >
> > -static inline int bbb_register_i2c_0( void )
> > -{
> > -  return am335x_i2c_bus_register(
> > -    BBB_I2C_0_BUS_PATH,
> > -    AM335X_I2C0_BASE,
> > -    I2C_BUS_CLOCK_DEFAULT,
> > -    BBB_I2C0_IRQ
> > -  );
> > -}
> > -
> >  static inline int bbb_register_i2c_1( void )
> >  {
> >    return am335x_i2c_bus_register(
> > diff --git a/bsps/arm/beagle/start/bspstart.c
> b/bsps/arm/beagle/start/bspstart.c
> > index 224f9ecf3b..8112e0867d 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 +43,17 @@ uint32_t bsp_fdt_map_intr(const uint32_t *intr,
> size_t icells)
> >  {
> >    return intr[0];
> >  }
> > +
> > +static void bbb_i2c_0_initialize(void)
> > +{
> > +  am335x_i2c_bus_register(BBB_I2C_0_BUS_PATH,
> > +                          AM335X_I2C0_BASE,
> > +                          I2C_BUS_CLOCK_DEFAULT,
> > +                          BBB_I2C0_IRQ);
> > +}
> > +
> > +RTEMS_SYSINIT_ITEM(
> > +  bbb_i2c_0_initialize,
> > +  RTEMS_SYSINIT_LAST,
> > +  RTEMS_SYSINIT_ORDER_LAST
> > +);
> >
>
>
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