GPIO setting

[Ivor Kruger]

Hi, actually, I found my problem.

You know how they say that assumptions are the mother of all screw ups…

Well I assumed that the function set_muxconf_regs() was called in the init
function…upon checking I found that it was not, thus the mux was just set
to the default values and no amount of editing in the settings made a
difference.

So I added it to  be the first line in the "static int
pcm049_devices_init(void)” function.

Now the mux gets configured correctly.

Regards
Ivor


On 2014/03/18, 11:21 AM, "Ivor Kruger" <ivor at veriline.co.za> wrote:

>Hi, I am still having a problem with the GPIO.
>
>When I check the mux registers for the GPIO pins I want to use, i get:
>
>barebox at Phytec phyCORE pcm049:/ md 0x4a100130
>4a100130: 00070118 00070007 00070007 00070007
>................
>4a100140: 00000118 00000100 01180118 01180118
>................
>
>This indicates that the pins are still in safe mode despite the settings
>of below in the mux.c file.
>
>{MCSPI1_CLK, (M3)},					/* gpio134 */
>	{MCSPI1_SOMI, (M3)},					/* gpio135 */
>	{MCSPI1_SIMO, (M3)},					/* gpio136 */
>	{MCSPI1_CS0, (M3)},					/* gpio137 */
>	{MCSPI1_CS1, (M3)},					/* gpio138 */
>	{MCSPI1_CS2, (M3)},					/* gpio139 */
>	{MCSPI1_CS3, (M3)},					/* gpio140 */
>
>In the board file I have the following code:
>
>static int pcm049_devices_init(void)
>{
>	i2c_register_board_info(0, i2c_devices, ARRAY_SIZE(i2c_devices));
>	omap44xx_add_i2c1(NULL);
>	omap44xx_add_mmc1(NULL);
>
>	gpmc_generic_init(0x10);
>
>	pcm049_network_init();
>
>	omap_add_gpmc_nand_device(&nand_plat);
>
>#ifdef CONFIG_PARTITION
>	devfs_add_partition("nand0", 0x00000, SZ_128K, DEVFS_PARTITION_FIXED,
>"xload_raw");
>	dev_add_bb_dev("xload_raw", "xload");
>	devfs_add_partition("nand0", SZ_128K, SZ_512K, DEVFS_PARTITION_FIXED,
>"self_raw");
>	dev_add_bb_dev("self_raw", "self0");
>	devfs_add_partition("nand0", SZ_128K + SZ_512K, SZ_128K,
>DEVFS_PARTITION_FIXED, "env_raw");
>	dev_add_bb_dev("env_raw", "env0");
>#endif
>
>	armlinux_set_bootparams((void *)0x80000100);
>	armlinux_set_architecture(MACH_TYPE_PCM049);
>
>	omap_add_display(&pcm049_fb_data);
>
>	gpio_direction_output(134, 1);
>	gpio_direction_output(135, 1);
>	gpio_direction_output(136, 1);
>	gpio_direction_output(137, 1);
>	gpio_direction_output(138, 0);
>	gpio_direction_output(139, 0);
>	gpio_direction_output(140, 0);
>
>	return 0;
>}
>
>If I do a mw 0x4a10013c 0x00030003 the register is changed as expected. I
>can then use the gpio_direction_output command to toggle the pin.
>
>
>So the problem clearly lies within the way the mux registers are
>configured.
>
>Any ideas on what I am doing wrong
>
>Vielen dank
>Ivor
>
>
>
>
>
>On 2014/03/17, 2:09 PM, "Sascha Hauer" <s.hauer at pengutronix.de> wrote:
>
>>On Mon, Mar 17, 2014 at 10:47:06AM +0200, Ivor Kruger wrote:
>>> Hi, sure this is a quick and easy question for the group?
>>> 
>>> On the OMAP4430, using the command from within barebox prompt to
>>>configure
>>> a GPIO for testing hardware:
>>> 
>>> gpio_direction_output 140 0
>>> 
>>> Should this be sufficient to set the gpio pin low, or is it required to
>>> still do some pin muxing as well?
>>
>>The gpio functions only configure the gpio controller. If this pin is
>>not gpio by default, you have to configure the pinmux controller aswell.
>>There is no way to do that on the barebox commandline other than direct
>>register
>>writes to the pinmux controller.
>>
>>Sascha
>>
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