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TDA4AL-Q1: How to read main_gpio status in uboot

Namic Chang
Prodigy 250 points
Part Number: TDA4AL-Q1

Hi,

I would like to read the status of main_gpio.

I have referred to the detect_enable_hyperflash function in board/ti/j721e/evm.c, and it only read the wkup_gpio.

For main_gpio, how to modify?

Thanks.

Best regards,

Namic Chang

  • 0
    TI__Mastermind 47983 points

    Thanks for your query. Due to the regional holiday, please expect a 1~2 day delay in responses. Apologies for the delay, and thank you for your patience.

  • 0 in reply to Praveen Rao
    TI__Guru 50503 points

    Hi Namic,

    If wanting to read main_gpio pins in u-boot, I would recommend referencing this E2E thread where a user toggles and reads GPIO pins in u-boot: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1084498/tda4vm-q1-how-to-control-gpio-on-tda4-uboot

    If you are already doing some experiments with some u-boot commands and not seeing any changes, my first suspicion is that pinmuxing is not being done in device tree, similar to the E2E that I have linked.

    Regards,

    Takuma

  • 0 in reply to Takuma Fujiwara
    Prodigy 250 points

    Hi, Takuma:

    Thanks for your reply.

    I have add pin mux in dtsi for main_gpio pins and set them to PIN_INPUT.

    &main_gpio0 {
	pinctrl-names = "default";
	pinctrl-0 = <&main_gpio0_pins_default>;
};

&main_pmx0 {
	main_gpio0_pins_default: main-gpio0-pins-default {
		pinctrl-single,pins = <
			J721S2_IOPAD(0x06c, PIN_INPUT, 7) /* (V26) MCAN1_TX.GPIO0_27 */
			J721S2_IOPAD(0x078, PIN_INPUT, 7) /* (Y25) MCAN2_RX.GPIO0_30 */
		>;
	};
};

    But I used dm_gpio_lookup_name(), dm_gpio_request() and dm_gpio_get_value() to access the two pins, I would get the result of wkup_gpio.

    So, how can I use these dm_gpio_xxx functions to get the value of main_gpio ?

    Thanks.

    Best regards,

    Namic Chang

  • 0 in reply to Namic Chang
    TI__Guru 50503 points

    Hi Namic,

    I am not too familiar with dm_gpio_lookup_name() in U-Boot. However, my next suspicion after pinmuxing would be related to offsets for GPIO as this is a common issue when interfacing with GPIO in general.

    If you stop in U-Boot by pressing any keys when prompted, you can do "gpio status -a" to print out all the GPIO banks. What I see on my end is the following on TDA4AL:

    Fullscreen u-boot-j721s2-gpio.txt Download 
    => gpio status -a
0: input: 0 [ ]
1: input: 1 [ ]
2: input: 1 [ ]
3: input: 0 [ ]
4: input: 0 [ ]
5: input: 0 [ ]
6: input: 0 [ ]
7: input: 0 [ ]
8: input: 0 [ ]
9: input: 0 [ ]
10: input: 0 [ ]
11: input: 0 [ ]
12: input: 0 [ ]
13: input: 1 [ ]
14: input: 1 [ ]
15: input: 1 [ ]
16: input: 0 [ ]
17: input: 1 [ ]
18: input: 0 [ ]
19: input: 1 [ ]
20: input: 1 [ ]
21: input: 0 [ ]
22: input: 0 [ ]
23: input: 1 [ ]
24: input: 1 [ ]
25: input: 0 [ ]
26: input: 0 [ ]
27: input: 0 [ ]
28: input: 0 [ ]
29: input: 0 [ ]
30: input: 0 [ ]
31: input: 0 [ ]
32: input: 1 [ ]
33: input: 0 [ ]
34: input: 0 [ ]
35: input: 0 [ ]
36: input: 0 [ ]
37: input: 0 [ ]
38: input: 0 [ ]
39: input: 0 [ ]
40: input: 0 [ ]
41: input: 0 [ ]
42: input: 0 [ ]
43: input: 0 [ ]
44: input: 0 [ ]
45: input: 0 [ ]
46: input: 0 [ ]
47: input: 1 [ ]
48: input: 0 [ ]
49: input: 0 [ ]
50: input: 0 [ ]
51: input: 0 [ ]
52: input: 1 [ ]
53: input: 0 [ ]
54: input: 0 [ ]
55: input: 0 [ ]
56: input: 1 [ ]
57: input: 1 [ ]
58: input: 1 [ ]
59: input: 0 [ ]
60: input: 0 [ ]
61: input: 0 [ ]
62: input: 0 [ ]
63: input: 1 [ ]
64: input: 1 [ ]
65: input: 1 [ ]
66: input: 1 [ ]
67: input: 0 [ ]
68: input: 0 [ ]
69: input: 0 [ ]
70: input: 0 [ ]
71: input: 0 [ ]
72: input: 0 [ ]
73: input: 0 [ ]
74: input: 0 [ ]
75: input: 0 [ ]
76: input: 0 [ ]
77: input: 0 [ ]
78: input: 0 [ ]
79: input: 0 [ ]
80: input: 0 [ ]
81: input: 0 [ ]
82: input: 0 [ ]
83: input: 0 [ ]
84: input: 0 [ ]
85: input: 0 [ ]
86: input: 0 [ ]
87: input: 1 [ ]
88: input: 0 [ ]
0: input: 0 [ ]
1: input: 0 [ ]
2: input: 0 [ ]
3: input: 0 [ ]
4: input: 0 [ ]
5: input: 0 [ ]
6: input: 0 [ ]
7: input: 0 [ ]
8: input: 0 [ ]
9: input: 0 [ ]
10: input: 0 [ ]
11: input: 0 [ ]
12: input: 0 [ ]
13: input: 0 [ ]
14: input: 0 [ ]
15: input: 0 [ ]
16: input: 1 [ ]
17: input: 0 [ ]
18: input: 0 [ ]
19: input: 0 [ ]
20: input: 0 [ ]
21: input: 0 [ ]
22: input: 0 [ ]
23: input: 0 [ ]
24: input: 0 [ ]
25: input: 0 [ ]
26: input: 0 [ ]
27: input: 0 [ ]
28: input: 0 [ ]
29: input: 0 [ ]
30: input: 0 [ ]
31: input: 0 [ ]
32: input: 0 [ ]
33: input: 0 [ ]
34: input: 0 [ ]
35: input: 0 [ ]
36: input: 0 [ ]
37: input: 0 [ ]
38: input: 0 [ ]
39: input: 0 [ ]
40: input: 0 [ ]
41: input: 0 [ ]
42: input: 0 [ ]
43: input: 0 [ ]
44: input: 0 [ ]
45: input: 0 [ ]
46: input: 0 [ ]
47: input: 0 [ ]
48: input: 0 [ ]
49: input: 0 [ ]
50: input: 0 [ ]
51: input: 0 [ ]
52: input: 1 [ ]
53: input: 0 [ ]
54: input: 0 [ ]
55: input: 0 [ ]
56: input: 1 [ ]
57: input: 1 [ ]
58: input: 0 [ ]
59: input: 0 [ ]
60: input: 1 [ ]
61: input: 1 [ ]
62: input: 1 [ ]
63: input: 1 [ ]
64: input: 1 [ ]
65: input: 1 [ ]
Bank gpio@21_:
gpio@21_0: input: 0 [ ]
gpio@21_1: input: 0 [ ]
gpio@21_2: input: 0 [ ]
gpio@21_3: input: 1 [ ]
gpio@21_4: input: 0 [ ]
gpio@21_5: input: 1 [ ]
gpio@21_6: input: 0 [ ]
gpio@21_7: input: 1 [ ]

Bank gpio@20_:
gpio@20_0: input: 0 [ ]
gpio@20_1: input: 0 [ ]
gpio@20_2: input: 0 [ ]
gpio@20_3: input: 0 [ ]
gpio@20_4: input: 0 [ ]
gpio@20_5: input: 0 [ ]
gpio@20_6: input: 0 [ ]
gpio@20_7: input: 0 [ ]
gpio@20_8: input: 0 [ ]
gpio@20_9: input: 0 [ ]
gpio@20_10: input: 1 [ ]
gpio@20_11: input: 1 [ ]
gpio@20_12: input: 0 [ ]
gpio@20_13: input: 0 [ ]
gpio@20_14: input: 0 [ ]
gpio@20_15: input: 1 [ ]

Bank gpio@22_:
gpio@22_0: input: 0 [ ]
gpio@22_1: input: 0 [ ]
gpio@22_2: input: 1 [ ]
gpio@22_3: input: 1 [ ]
gpio@22_4: input: 0 [ ]
gpio@22_5: input: 0 [ ]
gpio@22_6: input: 0 [ ]
gpio@22_7: input: 0 [ ]
gpio@22_8: input: 0 [ ]
gpio@22_9: input: 1 [ ]
gpio@22_10: input: 0 [ ]
gpio@22_11: input: 0 [ ]
gpio@22_12: input: 0 [ ]
gpio@22_13: input: 0 [ ]
gpio@22_14: input: 0 [ ]
gpio@22_15: input: 1 [ ]
gpio@22_16: input: 1 [ ]
gpio@22_17: input: 0 [ ]
gpio@22_18: input: 0 [ ]
gpio@22_19: input: 0 [ ]
gpio@22_20: input: 0 [ ]
gpio@22_21: input: 0 [ ]
gpio@22_22: input: 1 [ ]
gpio@22_23: input: 1 [ ]

    When referencing datasheet's section 6.3.3 GPIO (https://www.ti.com/lit/ds/symlink/tda4vl-q1.pdf), you can find the number of WKUP_GPIO pins are 0~88 and MAIN_GPIO pins are 0~65.

    • The first bank that comes up in the logs from "gpio status -a" is 0~88 which matches the number of GPIO pins under WKUP_GPIO
    • The second bank in the log is 0~65 which matches the number of MAIN_GPIO
    • The third bank of gpio@21 and onwards are defined in device tree as I2C GPIO expanders. 

    My assumption is that dm_gpio_lookup_name is using similar methods to access the available GPIO pins as the command line gpio tool. If this is true, then it could be that the first 0~88 pins are for wkup_gpio and the next 89~154 pins after the wkup_gpio pins are the main_gpio pins.

    Regards,

    Takuma