[U-Boot] [PATCH] overo: add SPL support

[Andreas Müller]

On Wednesday, December 14, 2011 06:24:13 PM Steve Sakoman wrote:
> 
> I think you will also need to update the get_board_revision function
> to ensure that SPL works with very early Overo revisions.
> 
> Note this excerpt from the X-loader get_board_revision funtion:
> 
> 	/* board revisions <= R2410 connect 4030 irq_1 to gpio112             */
> 	/* these boards should return a revision number of 0                  */
> 	/* the code below forces a 4030 RTC irq to ensure that gpio112 is low */
> #ifdef CONFIG_DRIVER_OMAP34XX_I2C
> 	i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);
> 	data = 0x01;
> 	i2c_write(0x4B, 0x29, 1, &data, 1);
> 	data = 0x0c;
> 	i2c_write(0x4B, 0x2b, 1, &data, 1);
> 	i2c_read(0x4B, 0x2a, 1, &data, 1);
> #endif
> 
> Yup, ugly, but this is the only way to detect revision properly on those
> boards.
I tried the following (as you can see I already commented out the i2c-read-write 
for test):

int get_board_revision(void)
{
#ifdef CONFIG_DRIVER_OMAP34XX_I2C
	i2c_set_bus_num(TWL4030_I2C_BUS);
	/*data = 0x01;
	i2c_write(0x4B, 0x29, 1, &data, 1);
	data = 0x0c;
	i2c_write(0x4B, 0x2b, 1, &data, 1);
	i2c_read(0x4B, 0x2a, 1, &data, 1);*/
#endif
....
}

SPL Boot process hangs on i2c_set_bus_num ( tested by removing i2c_set_bus_num -
> proper operation ) with console freeze:

| U-Boot SPL 2011.12-rc1-00004-g06e42c6-dirty (Dec 15 2011 - 14:03:34)
| Texas Instruments Revision detection unimplemented

The call stack for get_board_revision() is for SPL

s_init()
mem_init()
do_sdrc_init(..)
get_board_mem_timings(..)
get_board_revision(..)

It seems that the call to i2c_set_bus_num comes too early. Before I dive into x-
loader analysis: Has anybody an idea what goes wrong?

Andreas