On Mon, Dec 19, 2011 at 6:03 PM, Andreas Müller schnitzeltony@gmx.de wrote:
On Thursday, December 15, 2011 10:12:59 PM Andreas Müller wrote:
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", ¤t_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.
'objdump -dSt' shows (the memory mappings I attached were not really helpful - sorry next time I know):
4020ae14 l O .data 00000004 i2c_base 80000068 l O .bss 00000004 current_bus 8000006c l O .bss 0000000c bus_initialized
'i2c_base' is correctly located in SRAM but 'current_bus' and 'bus_initialized' are located in CS0 SDRAM which is at the time of call not yet initalized. This fits to the crash behaviour: Accessing 'i2c_base' does not cause trouble. How can I move 'current_bus' and 'bus_initialized' to SRAM?
Ah-ha! Good work. If you initialize them to a non-zero value, statically (and make sure the code doesn't assume they're 0 by default), this will change.