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

15 Dec 2011


      On Thu, Dec 15, 2011 at 7:34 AM, Andreas Müller schnitzeltony@gmx.de wrote:
...
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.
Sorry for spamming but I face black magic:
I added debug messages in omap24xx_i2c.c / i2c_set_bus_num().
* Version 1:
int i2c_set_bus_num(unsigned int bus)
{
    puts("i2c_set_bus_num called 1\n");
    if ((bus < 0) || (bus >= I2C_BUS_MAX)) {
    	printf("Bad bus: %d\n", bus);
    	return -1;
    }
    printf("Bus: %d\n", bus);
#if I2C_BUS_MAX == 3
    if (bus == 2) {
    	puts("i2c_set_bus_num called 2\n");
    	i2c_base = (struct i2c *)I2C_BASE3;
    	puts("i2c_set_bus_num called 3\n");
    }
    else
#endif
    if (bus == 1) {
    	puts("i2c_set_bus_num called 4\n");
    	i2c_base = (struct i2c *)I2C_BASE2;
    	puts("i2c_set_bus_num called 5\n");
    }
    else {
    	puts("i2c_set_bus_num called 6\n");
    	i2c_base = (struct i2c *)I2C_BASE1;
    	puts("i2c_set_bus_num called 7\n");
    }
puts("i2c_set_bus_num called 8\n");
-->	current_bus = bus;
puts("i2c_set_bus_num called 9\n");
    if (!bus_initialized[current_bus])
    	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
}
leads to
i2c_set_bus_num called 1
Bus: 0
i2c_set_bus_num called 6
i2c_set_bus_num called 7
i2c_set_bus_num called 8
* Version 2:
int i2c_set_bus_num(unsigned int bus)
{
    puts("i2c_set_bus_num called 1\n");
    if ((bus < 0) || (bus >= I2C_BUS_MAX)) {
    	printf("Bad bus: %d\n", bus);
    	return -1;
    }
    printf("Bus: %d\n", bus);
-->	printf("CurrentBus: %d\n", current_bus);
    printf("AdrCurrentBus: %X\n", &current_bus);
#if I2C_BUS_MAX == 3
    if (bus == 2) {
    	puts("i2c_set_bus_num called 2\n");
    	i2c_base = (struct i2c *)I2C_BASE3;
    	puts("i2c_set_bus_num called 3\n");
    }
    else
#endif
    if (bus == 1) {
    	puts("i2c_set_bus_num called 4\n");
    	i2c_base = (struct i2c *)I2C_BASE2;
    	puts("i2c_set_bus_num called 5\n");
    }
    else {
    	puts("i2c_set_bus_num called 6\n");
    	i2c_base = (struct i2c *)I2C_BASE1;
    	puts("i2c_set_bus_num called 7\n");
    }
puts("i2c_set_bus_num called 8\n");
    current_bus = bus;
puts("i2c_set_bus_num called 9\n");
    if (!bus_initialized[current_bus])
    	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
}
leads to
i2c_set_bus_num called 1
Bus: 0
It seems that accessing 'current_bus' causes trouble. Has anybody an 
explanation for that? I don't think this is related to i2c or overo. For a 
better picture I attached memory mappings.
Since I do not have JTAG for debugging, I think x-loader is also nice :(
Regards
Andreas