pinmux u-boot custom board am335x

Laurens Miers

Hi,

I'm trying to get u-boot to work on my custom board based on am335x.

I recently deleted the calls to the EEPROM because my board doesn't have this and altered the V_OSCK to 26 Mhz because the board used this frequency ( I can't change this ).

But I'm having some trouble with the pinmux.

I will try to explain what I tried.

I received the header files needed for the pinmux from my colleagues, these were originally designed for Windows CE running on the custom board. You can find them here :

4606.pinmux_one.h

5187.pinmux_two.h

Then I tried to alter the pinmux:

I deleted the mux.c in <u-boot>/arch/arm/cpu/armv7/am33xx (and altered the Makefile for the compile error.) I did this because I thought everything would be handled by the MUX_EVM macro function in pinmux_one.h .

UPDATE: The above step, the deletion of mux.c is not required. I was wrong at the time of the deletion. I think it's ok to leave the file as it is and not worry about it.

I altered the mux.c in <u-boot>/board/ti/am335x to include the pinmux_one.h and changed the enable_board_pin_mux function to :

void enable_board_pin_mux(struct am335x_baseboard_id *header)
{	
		MUX_EVM();
	
}

I then replaced mux.h in <u-boot>/include/asm/arch-am33xx with pinmux_two.h ( but I kept the name mux.h for proper dependencies).

Then I commented out ( in board/ti/am33x/board.c ):

#ifdef CONFIG_SERIAL1
	enable_uart0_pin_mux();
#endif /* CONFIG_SERIAL1 */
#ifdef CONFIG_SERIAL2
	enable_uart1_pin_mux();
#endif /* CONFIG_SERIAL2 */
#ifdef CONFIG_SERIAL3
	enable_uart2_pin_mux();
#endif /* CONFIG_SERIAL3 */
#ifdef CONFIG_SERIAL4
	enable_uart3_pin_mux();
#endif /* CONFIG_SERIAL4 */
#ifdef CONFIG_SERIAL5
	enable_uart4_pin_mux();
#endif /* CONFIG_SERIAL5 */
#ifdef CONFIG_SERIAL6
	enable_uart5_pin_mux();
#endif /* CONFIG_SERIAL6 */

and

enable_i2c0_pin_mux();

because I think that this would be taken care of in the MUX_EVM() macro.

When I boot the board I get weird output until u-boot invokes the following function in /board/ti/am33xx/board.c :

config_ddr(303, MT41J128MJT125_IOCTRL_VALUE, &ddr3_data,
&ddr3_cmd_ctrl_data, &ddr3_emif_reg_data);

I only use this config_ddr because my board uses ddr3 like the Starter kit, the others are commented out.

Then regular output begins but it stops booting. They thought the booting stopped because I hadn't properly configured DDR3 yet.

They gave me this for the DDR3:

2703.ddr3.h

I guess I have to use this in <u-boot>/arch/arm/cpu/armv7/am33xx/ddr.c and <u-boot>/arch/arm/include/asm/arch-am33xx/ddr_defs.h but I want to make sure first if I am doing the pinmux right.

Or am I screwing things up?

Thanks in advance.

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Laurens,

Can you say what versions of Linux / u-boot you are using?

0 Laurens Miers over 11 years ago in reply to Biser Gatchev-XID

Intellectual 640 points

I'm using the u boot and linux from the ti-sdk-am335x-evm-06.00.00.00:

u-boot version : uBoot-v2013.01 ( u-boot-2013.01.01-psp06.00.00.00)

Linux version: linux-3.2.0 (linux-3.2.0-psp04.06.00.11)

But I'm only working on u-boot for the moment.

0 Biser Gatchev-XID over 11 years ago in reply to Laurens Miers

TI__Guru**** 393215 points

Hi Laurens,

Something I missed from your previous post: You say that your configuration is like the Starter Kit. In the SK schematics there is a GPIO that controls the DDR3 V_TT regulator (AM335X pin C18, ECAP0_IN_PWM0_OUT / UART3_TXD / SPI1_CS1 / PR1_ECAP0_ECAP_CAPIN_APWM_O / SPI1_SCLK / MMC0_SDWP / XDMA_EVENT_INTR2 / GPIO0_7). Net name is DDR_VTT_EN. The DDR3 interface will not function properly until the regulator is turned on (active high level). I suspect this is the problem you are facing.

0 Laurens Miers over 11 years ago in reply to Biser Gatchev-XID

Intellectual 640 points

Well my board uses DDR3 like the Starter kit but it's closer to the EVM but it hasn't got boot pins, etc.. And in the file <u-boot>/board/ti/am33xx/board.c I thought I activated it with the following code :

/*
		 * EVM SK 1.2A and later use gpio0_7 to enable DDR3.
		 * This is safe enough to do on older revs.
		 */
		gpio_request(GPIO_DDR_VTT_EN, "ddr_vtt_en");
		gpio_direction_output(GPIO_DDR_VTT_EN, 1);

But I haven't altered the pinmux or timings for the DDR3 so I'll have to get this right first, right?

But what I was wondering is if I have done the pinmux of the rest ok ? Well I mean if this is the way it's supposed to be done?

I wanted to know this before screwing around with the ddr3 :).

And the files I have to alter for the DDR3 are :

<u-boot>/arch/arm/cpu/armv7/am33xx/ddr.c

<u-boot>/arch/arm/include/asm/arch-am33xx/ddr_defs.h

Or am I missing something? I understood that these were the files needed from the tutorials here ( see your post in the following thread http://e2e.ti.com/support/arm/sitara_arm/f/791/t/297692.aspx ):

http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips

http://processors.wiki.ti.com/index.php/AM335x_DDR_PHY_register_configuration_for_DDR3

http://processors.wiki.ti.com/index.php/Sitara_Linux_Training:_Tuning_the_DDR3_Timings_on_BeagleBoneBlack

0 Biser Gatchev-XID over 11 years ago in reply to Laurens Miers

TI__Guru**** 393215 points

Yes, you have to do the pinmux for GPIO_DDR_VTT_EN before changing its state. The DDR tutorials are the right ones too.

0 Miroslav Kiradzhiyski XID over 11 years ago in reply to Laurens Miers

TI__Mastermind 25235 points

Laurens Miers said:
But what I was wondering is if I have done the pinmux of the rest ok ? Well I mean if this is the way it's supposed to be done?

Laurens Miers said:
I deleted the mux.c in <u-boot>/arch/arm/cpu/armv7/am33xx (and altered the Makefile for the compile error.) I did this because I thought everything would be handled by the MUX_EVM macro function in pinmux_one.h .

Why did you delete the mux.c file?

Please read this guide on how to use the generated mux.h and pinmux.h header files. These file names should remain mux.h and pinmux.h, not pinmux_one.h and pinmux_two.h.

Best regards,
Miroslav

0 Laurens Miers over 11 years ago in reply to Miroslav Kiradzhiyski XID

Intellectual 640 points

I deleted the mux.c file because i thought everything would be handled by the MUX_EVM macro.

But I (think I ) succeeded in booting u-boot.

It just keeps giving this message :

wait_for_user_access Timeout

and eventually goes to the prompt. I did some research and found that this line:

rv = cpsw_register(&cpsw_data);

gave the message. I understand it is to configure an ethernet port ( from this post: http://e2e.ti.com/support/arm/sitara_arm/f/791/p/298976/1043051.aspx) but my board doesn't have an ethernet port, only wifi. So do I have to concern myself with this problem or can I just leave the above code commented?

Thanks for all the info and help.

0 Miroslav Kiradzhiyski XID over 11 years ago in reply to Laurens Miers

TI__Mastermind 25235 points

Hi Laurens,

Since you don't have any ethernet ports on your custom board, disable CONFIG_PHYLIB and CONFIG_ETHERNET in the kernel config and then rebuild the kernel.

Best regards,
Miroslav

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pinmux u-boot custom board am335x