int mhi_async_power_up()

in mhi/core/pm.c [1050:1131]

• 58 lines of code
• 10 McCabe index (conditional complexity)

int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
{
	enum mhi_state state;
	enum mhi_ee_type current_ee;
	enum dev_st_transition next_state;
	struct device *dev = &mhi_cntrl->mhi_dev->dev;
	u32 interval_us = 25000; /* poll register field every 25 milliseconds */
	int ret;

	dev_info(dev, "Requested to power ON\n");

	/* Supply default wake routines if not provided by controller driver */
	if (!mhi_cntrl->wake_get || !mhi_cntrl->wake_put ||
	    !mhi_cntrl->wake_toggle) {
		mhi_cntrl->wake_get = mhi_assert_dev_wake;
		mhi_cntrl->wake_put = mhi_deassert_dev_wake;
		mhi_cntrl->wake_toggle = (mhi_cntrl->db_access & MHI_PM_M2) ?
			mhi_toggle_dev_wake_nop : mhi_toggle_dev_wake;
	}

	mutex_lock(&mhi_cntrl->pm_mutex);
	mhi_cntrl->pm_state = MHI_PM_DISABLE;

	/* Setup BHI INTVEC */
	write_lock_irq(&mhi_cntrl->pm_lock);
	mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
	mhi_cntrl->pm_state = MHI_PM_POR;
	mhi_cntrl->ee = MHI_EE_MAX;
	current_ee = mhi_get_exec_env(mhi_cntrl);
	write_unlock_irq(&mhi_cntrl->pm_lock);

	/* Confirm that the device is in valid exec env */
	if (!MHI_POWER_UP_CAPABLE(current_ee)) {
		dev_err(dev, "%s is not a valid EE for power on\n",
			TO_MHI_EXEC_STR(current_ee));
		ret = -EIO;
		goto error_exit;
	}

	state = mhi_get_mhi_state(mhi_cntrl);
	dev_dbg(dev, "Attempting power on with EE: %s, state: %s\n",
		TO_MHI_EXEC_STR(current_ee), TO_MHI_STATE_STR(state));

	if (state == MHI_STATE_SYS_ERR) {
		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
				 MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0,
				 interval_us);
		if (ret) {
			dev_info(dev, "Failed to reset MHI due to syserr state\n");
			goto error_exit;
		}

		/*
		 * device cleares INTVEC as part of RESET processing,
		 * re-program it
		 */
		mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
	}

	ret = mhi_init_irq_setup(mhi_cntrl);
	if (ret)
		goto error_exit;

	/* Transition to next state */
	next_state = MHI_IN_PBL(current_ee) ?
		DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;

	mhi_queue_state_transition(mhi_cntrl, next_state);

	mutex_unlock(&mhi_cntrl->pm_mutex);

	dev_info(dev, "Power on setup success\n");

	return 0;

error_exit:
	mhi_cntrl->pm_state = MHI_PM_DISABLE;
	mutex_unlock(&mhi_cntrl->pm_mutex);

	return ret;
}