verstage.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <delay.h>
#include <gpio.h>
#include <security/vboot/vboot_common.h>
 
#define TPM_RESET_GPIO          19
 
static void ipq_setup_tpm(void)
{
 
        if (CONFIG(I2C_TPM)) {
                gpio_tlmm_config_set(TPM_RESET_GPIO, FUNC_SEL_GPIO,
                                     GPIO_PULL_UP, GPIO_6MA, 1);
                gpio_set(TPM_RESET_GPIO, 0);
                udelay(100);
                gpio_set(TPM_RESET_GPIO, 1);
 
                /*
                 * ----- Per the SLB 9615XQ1.2 spec -----
                 *
                 * 4.7.1 Reset Timing
                 *
                 * The TPM_ACCESS_x.tpmEstablishment bit has the correct value
                 * and the TPM_ACCESS_x.tpmRegValidSts bit is typically set
                 * within 8ms after RESET# is deasserted.
                 *
                 * The TPM is ready to receive a command after less than 30 ms.
                 *
                 * --------------------------------------
                 *
                 * I'm assuming this means "wait for 30ms"
                 *
                 * If we don't wait here, subsequent QUP I2C accesses
                 * to the TPM either fail or timeout.
                 */
                mdelay(30);
        }
}
 
void verstage_mainboard_init(void)
{
        ipq_setup_tpm();
}