GPIO initialization about IMX8MQ on power

[Joe_C]

When the IMX8MQ SoC is powered on, the UBOOT initializes GPIO in the BOARD_EARLY_INIT_F function.However, GPIO is not controlled at the moment of power on, what should I do to achieve such control effect?thank you.

[weidong_sun]

Hi,

  in spl.c of i.mx8mq board , there is example code for GPIO opreations:

...

#define USDHC2_CD_GPIO IMX_GPIO_NR(2, 12)
#define USDHC1_PWR_GPIO IMX_GPIO_NR(2, 10)
#define USDHC2_PWR_GPIO IMX_GPIO_NR(2, 19)

int board_mmc_getcd(struct mmc *mmc)
{
struct fsl_esdhc_cfg *cfg = (struct fsl_esdhc_cfg *)mmc->priv;
int ret = 0;

switch (cfg->esdhc_base) {
case USDHC1_BASE_ADDR:
ret = 1;
break;
case USDHC2_BASE_ADDR:
ret = !gpio_get_value(USDHC2_CD_GPIO);
return ret;
}

return 1;
}

#define USDHC_PAD_CTRL (PAD_CTL_DSE6 | PAD_CTL_HYS | PAD_CTL_PUE | \
PAD_CTL_FSEL2)
#define USDHC_GPIO_PAD_CTRL (PAD_CTL_PUE | PAD_CTL_DSE1)

static iomux_v3_cfg_t const usdhc1_pads[] = {
IMX8MQ_PAD_SD1_CLK__USDHC1_CLK | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_CMD__USDHC1_CMD | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA0__USDHC1_DATA0 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA1__USDHC1_DATA1 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA2__USDHC1_DATA2 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA3__USDHC1_DATA3 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA4__USDHC1_DATA4 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA5__USDHC1_DATA5 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA6__USDHC1_DATA6 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_DATA7__USDHC1_DATA7 | MUX_PAD_CTRL(USDHC_PAD_CTRL),
IMX8MQ_PAD_SD1_RESET_B__GPIO2_IO10 | MUX_PAD_CTRL(NO_PAD_CTRL),
};

static iomux_v3_cfg_t const usdhc2_pads[] = {
IMX8MQ_PAD_SD2_CLK__USDHC2_CLK | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0xd6 */
IMX8MQ_PAD_SD2_CMD__USDHC2_CMD | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0xd6 */
IMX8MQ_PAD_SD2_DATA0__USDHC2_DATA0 | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0xd6 */
IMX8MQ_PAD_SD2_DATA1__USDHC2_DATA1 | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0xd6 */
IMX8MQ_PAD_SD2_DATA2__USDHC2_DATA2 | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0x16 */
IMX8MQ_PAD_SD2_DATA3__USDHC2_DATA3 | MUX_PAD_CTRL(USDHC_PAD_CTRL), /* 0xd6 */
IMX8MQ_PAD_SD2_CD_B__GPIO2_IO12 | MUX_PAD_CTRL(USDHC_GPIO_PAD_CTRL),
IMX8MQ_PAD_SD2_RESET_B__GPIO2_IO19 | MUX_PAD_CTRL(USDHC_GPIO_PAD_CTRL),
};

static struct fsl_esdhc_cfg usdhc_cfg[2] = {
{USDHC1_BASE_ADDR, 0, 8},
{USDHC2_BASE_ADDR, 0, 4},
};

int board_mmc_init(bd_t *bis)
{
int i, ret;
/*
* According to the board_mmc_init() the following map is done:
* (U-Boot device node) (Physical Port)
* mmc0 USDHC1
* mmc1 USDHC2
*/
for (i = 0; i < CONFIG_SYS_FSL_USDHC_NUM; i++) {
switch (i) {
case 0:
init_clk_usdhc(0);
usdhc_cfg[0].sdhc_clk = mxc_get_clock(MXC_ESDHC_CLK);
imx_iomux_v3_setup_multiple_pads(usdhc1_pads,
ARRAY_SIZE(usdhc1_pads));
gpio_request(USDHC1_PWR_GPIO, "usdhc1_reset");
gpio_direction_output(USDHC1_PWR_GPIO, 0);
udelay(500);
gpio_direction_output(USDHC1_PWR_GPIO, 1);
break;
case 1:
init_clk_usdhc(1);
usdhc_cfg[1].sdhc_clk = mxc_get_clock(MXC_ESDHC2_CLK);
imx_iomux_v3_setup_multiple_pads(usdhc2_pads,
ARRAY_SIZE(usdhc2_pads));
gpio_request(USDHC2_PWR_GPIO, "usdhc2_reset");
gpio_direction_output(USDHC2_PWR_GPIO, 0);
udelay(500);
gpio_direction_output(USDHC2_PWR_GPIO, 1);
break;
default:
printf("Warning: you configured more USDHC controllers(%d) than supported by the board\n", i + 1);
return -EINVAL;
}

ret = fsl_esdhc_initialize(bis, &usdhc_cfg[i]);
if (ret)
return ret;
}

return 0;
}

....

You can refer to them.

weidong

[weidong_sun]

Hi,

   The API interface of dm-gpio is used in u-boot. There are already examples in imx8mq_evk.c: 

struct gpio_desc type_sel_desc;
static iomux_v3_cfg_t ss_mux_gpio[] = {
IMX8MQ_PAD_NAND_RE_B__GPIO3_IO15 | MUX_PAD_CTRL(NO_PAD_CTRL),
};

void ss_mux_select(enum typec_cc_polarity pol)
{
if (pol == TYPEC_POLARITY_CC1)
dm_gpio_set_value(&type_sel_desc, 1);
else
dm_gpio_set_value(&type_sel_desc, 0);
}

static int setup_typec(void)
{
int ret;

imx_iomux_v3_setup_multiple_pads(ss_mux_gpio, ARRAY_SIZE(ss_mux_gpio));

ret = dm_gpio_lookup_name("GPIO3_15", &type_sel_desc);
if (ret) {
printf("%s lookup GPIO3_15 failed ret = %d\n", __func__, ret);
return -ENODEV;
}

ret = dm_gpio_request(&type_sel_desc, "typec_sel");
if (ret) {
printf("%s request typec_sel failed ret = %d\n", __func__, ret);
return -ENODEV;
}

dm_gpio_set_dir_flags(&type_sel_desc, GPIOD_IS_OUT);

ret = tcpc_init(&port, port_config, &ss_mux_select);
if (ret) {
printf("%s: tcpc init failed, err=%d\n",
__func__, ret);
}

return ret;
}

so you can refer to above source code to configure your GPIO.

Have a nice day!

B.R,

weidong

[Joe_C]

I did GPIO initialization in the board_early_init_f () function, which should be earlier than the method initialization you mentioned, but it will take 200ms to run this function after power on.

[weidong_sun]

If you want to use this GPIO early, you can also wire its code in spl.c. OK?

[Joe_C]

yes,I initialize the GPIO in spl_board_init(), and I still can't pull the GPIO up or down when I power it up.