On Mon, Dec 19, 2011 at 6:03 PM, Andreas Müller <schnitzelt...@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 <schnitzelt...@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.
--
Tom
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