TDA4VM: [TDA4] toggle gpio reset to ethernet phy when u-boot boot

Gibbs Shih

Intellectual 760 points

Part Number: TDA4VM

Hi, Expert

I need to toggle a gpio pin to an ethernet phy chip reset when u-boot boots.

this reset pin is low active, and I hope this toggle pin keep low about 2 sec after power on.

Thanks E2E give me some information, but these do not work for me

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/937659/am4378-ethernet-initialization

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1114738/processor-sdk-am335x-am335x-using-two-gpio-to-reset-two-different-ethernet-phy/4132350?tisearch=e2e-quicksearch&keymatch=reset-gpios#4132350

https://patchwork.kernel.org/project/linux-omap/patch/daa29a99-0a17-d316-57eb-3e6162938d8d@ti.com/

The toggle pin is GPIO0_30 (AF21)

so I try to modify device tree in u-boot

I set gpio0_30 reset active low after power on

&davinci_mdio {

	status = "okay";
	reset-gpios = <&main_gpio0 30 GPIO_ACTIVE_LOW>;
	reset-delay-us = <2000000>;
	initially-in-reset = <1>;

	phy0: ethernet-phy@0 {
		reg = <0>;
		max-speed = <100>;

	};
};

	main_gpio0: gpio@600000 {
		compatible = "ti,j721e-gpio", "ti,keystone-gpio";
		reg = <0x0 0x00600000 0x0 0x100>;
		gpio-controller;
		#gpio-cells = <2>;
		interrupt-parent = <&main_gpio_intr>;
		interrupts = <256>, <257>, <258>, <259>,
			     <260>, <261>, <262>, <263>;
		interrupt-controller;
		#interrupt-cells = <2>;
		ti,ngpio = <128>;
		ti,davinci-gpio-unbanked = <0>;
		power-domains = <&k3_pds 105 TI_SCI_PD_EXCLUSIVE>;
		clocks = <&k3_clks 105 0>;
		clock-names = "gpio";
	};

Do I miss something?

I think it should be work ....

Thanks very much

Gibbs

over 3 years ago

0 Keerthy J over 3 years ago

TI__Guru**** 167700 points

Hi Gibbs,

I believe the E2E that you are referring davinci_mdio node is from the kernel & not U-Boot.

The U-boot code for mdio is under: drivers/net/ti/cpsw_mdio.c & this does not have any code to handle or parse the reset-gpios properties that you have added:

reset-gpios = <&main_gpio0 30 GPIO_ACTIVE_LOW>;
reset-delay-us = <2000000>;

So you see no difference even after adding that.

Recommend you to go through:

drivers/net/sun8i_emac.c & parse the properties & make use of them to set gpio as per need.

Closing this.

- Keerthy

0 Gibbs Shih over 3 years ago in reply to Keerthy J

Intellectual 760 points

Thanks Keerthy.

ok ~ let's me check one thing again!

because I real find device tree configure in u-boot source code, the path as below :

ti-processor-sdk-linux-j7-evm-08_02_00_03\board-support\u-boot-2021.01+gitAUTOINC+44a87e3ab8-g44a87e3ab8\arch\arm\dts\ k3-j721e-common-proc-board.dts

ti-processor-sdk-linux-j7-evm-08_02_00_03\board-support\u-boot-2021.01+gitAUTOINC+44a87e3ab8-g44a87e3ab8\arch\arm\dts\ k3-j721e.dtsi

...etc

I modify some device tree properties about eMMC in u-boot source, and it works.

Do you mean these device tree code is useless?

I feel a little bit confuse, and I need to double check your meaning again.

Thanks very much

Gibbs

0 Keerthy J over 3 years ago in reply to Gibbs Shih

TI__Guru**** 167700 points

Gibbs Shih said:
I modify some device tree properties about eMMC in u-boot source, and it works.

Can you share that DT code? I see this when i search for reset-gpio under drivers:

drivers/i2c/acpi_i2c.c:                 acpi_dp_add_gpio(dsd, "reset-gpios", path,
drivers/i2c/acpi_i2c.c: gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset_gpio,
drivers/i2c/muxes/pca954x.c:            err = gpio_request_by_name(dev, "reset-gpios", 0,
drivers/misc/ihs_fpga.c:        ret = gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset_gpio,
drivers/mmc/meson_gx_mmc.c:     ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
drivers/mmc/rockchip_dw_mmc.c: ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
drivers/net/dwc_eth_qos.c:      ret = gpio_request_by_name(dev, "phy-reset-gpios", 0,
drivers/net/dwc_eth_qos.c:              /* search "reset-gpios" in phy node */
drivers/net/dwc_eth_qos.c:                                               "reset-gpios", 0,
drivers/net/fec_mxc.c: ret = gpio_request_by_name(dev, "phy-reset-gpios", 0,
drivers/net/mtk_eth.c:                  gpio_request_by_name(dev, "reset-gpios", 0,
drivers/net/mvneta.c:   gpio_request_by_name(dev, "phy-reset-gpios", 0,
drivers/net/mvpp2.c:    gpio_request_by_name(dev, "phy-reset-gpios", 0,
drivers/net/pic32_eth.c:        gpio_request_by_name_nodev(dev_ofnode(dev), "reset-gpios", 0,
drivers/net/ravb.c:             gpio_request_by_name_nodev(phandle_args.node, "reset-gpios", 0,
drivers/net/ravb.c:             gpio_request_by_name(dev, "reset-gpios", 0, &eth->reset_gpio,
drivers/net/sh_eth.c:           gpio_request_by_name_nodev(phandle_args.node, "reset-gpios", 0,
drivers/net/sh_eth.c:           gpio_request_by_name(udev, "reset-gpios", 0, &priv->reset_gpio,
drivers/pci/pci-aardvark.c:     gpio_request_by_name(dev, "reset-gpios", 0, &pcie->reset_gpio,
drivers/sysinfo/gazerbeam.c:    gpio_num = gpio_request_list_by_name(dev, "reset-gpios",
drivers/sysinfo/gazerbeam.c:            debug("%s: Error getting GPIO list 'reset-gpios' (err = %d)\n",
drivers/video/bridge/video-bridge-uclass.c:     ret = gpio_request_by_name(dev, "reset-gpios", 0, &uc_priv->reset,
drivers/video/bridge/video-bridge-uclass.c:             debug("%s: Could not decode reset-gpios (%d)\n", __func__, ret);
drivers/video/orisetech_otm8009a.c:     ret = gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset,
drivers/video/raydium-rm68200.c:        ret = gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset,

Typically the above drivers parse the reset-gpios property & toggle them as per need.
Can you confirm on your side when you say eMMC works? What is the DT diff & changes you did?

- Keerthy

0 Gibbs Shih over 3 years ago in reply to Keerthy J

Intellectual 760 points

HI, Keerthy

I'm not sure gpio toggle works in device tree, because I am finding the answer.

about gpio toggle, modiify device tree is not the only solutions, modify source code is also fine.

I may try to find the way.

For example, my experence in u-boot *.dts, information sharing with you:

Our customer board only support low speed SD boot,

SD boot divide two stage, u-boot boot and Linux boot.

SD u-boot boot base on low speed 3.3V, and linux boot base on high speed 1.8v

so you need to disable 1.8v , and keep low speed boot

changes as below.

SD card linux boot with "low speed" , 3.3v driven,

It's work, so it should be some function works in u-boot device tree.

Gibbs

+1 Keerthy J over 3 years ago in reply to Gibbs Shih

TI__Guru**** 167700 points

Hi Gibbs,

drivers/video/raydium-rm68200.c

In U-boot file. function: rm68200_panel_ofdata_to_platdata

        ret = gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset,
                                   GPIOD_IS_OUT);
        if (ret) {
                dev_err(dev, "Warning: cannot get reset GPIO\n");
                if (ret != -ENOENT)
                        return ret;
        }

Add some code like above in the driver where you want to control gpio.
You get the gpio handle in priv->reset

Then you can use something like below:

        /* reset panel */
        dm_gpio_set_value(&priv->reset, true);
        mdelay(1);
        dm_gpio_set_value(&priv->reset, false);
        mdelay(10);

to toggle.

You also need to make sure that pinmux is set properly for GPIO output mode like below example.

        sw10_button_pins_default: sw10-button-pins-default {
                pinctrl-single,pins = <
                        J721E_IOPAD(0x0, PIN_INPUT, 7) /* (AC18) EXTINTn.GPIO0_0 */
                >;
        };

in the file: arch/arm/dts/k3-j721e-common-proc-board.dts

- Keerthy

0 Gibbs Shih over 3 years ago in reply to Keerthy J

Intellectual 760 points

Hi, Keerthy

Thanks

I also found this thread which you replied for someone 4 month ago,

it should be useful

additional information here:

e2e.ti.com/.../tda4vm-q1-how-to-control-gpio-on-tda4-uboot

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TDA4VM: [TDA4] toggle gpio reset to ethernet phy when u-boot boot