drivers/slimbus/sched.c

Source file repositories/reference/linux-study-clean/drivers/slimbus/sched.c

File Facts

System
Linux kernel
Corpus path
drivers/slimbus/sched.c
Extension
.c
Size
3266 bytes
Lines
122
Domain
Driver Families
Bucket
drivers/slimbus
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (sched->clk_state == SLIM_CLK_ACTIVE) {
			mutex_unlock(&sched->m_reconf);
			return 0;
		}

		/*
		 * Fine-tune calculation based on clock gear,
		 * message-bandwidth after bandwidth management
		 */
		ret = wait_for_completion_timeout(&sched->pause_comp,
				msecs_to_jiffies(100));
		if (!ret) {
			mutex_unlock(&sched->m_reconf);
			pr_err("Previous clock pause did not finish");
			return -ETIMEDOUT;
		}
		ret = 0;

		/*
		 * Slimbus framework will call controller wakeup
		 * Controller should make sure that it sets active framer
		 * out of clock pause
		 */
		if (sched->clk_state == SLIM_CLK_PAUSED && ctrl->wakeup)
			ret = ctrl->wakeup(ctrl);
		if (!ret)
			sched->clk_state = SLIM_CLK_ACTIVE;
		mutex_unlock(&sched->m_reconf);

		return ret;
	}

	/* already paused */
	if (ctrl->sched.clk_state == SLIM_CLK_PAUSED) {
		mutex_unlock(&sched->m_reconf);
		return 0;
	}

	spin_lock_irqsave(&ctrl->txn_lock, flags);
	for (i = 0; i < SLIM_MAX_TIDS; i++) {
		/* Pending response for a message */
		if (idr_find(&ctrl->tid_idr, i)) {
			spin_unlock_irqrestore(&ctrl->txn_lock, flags);
			mutex_unlock(&sched->m_reconf);
			return -EBUSY;
		}
	}
	spin_unlock_irqrestore(&ctrl->txn_lock, flags);

	sched->clk_state = SLIM_CLK_ENTERING_PAUSE;

	/* clock pause sequence */
	ret = slim_do_transfer(ctrl, &txn);
	if (ret)
		goto clk_pause_ret;

	txn.mc = SLIM_MSG_MC_NEXT_PAUSE_CLOCK;
	txn.rl = 4;
	msg.num_bytes = 1;
	msg.wbuf = &restart;
	ret = slim_do_transfer(ctrl, &txn);
	if (ret)
		goto clk_pause_ret;

	txn.mc = SLIM_MSG_MC_RECONFIGURE_NOW;
	txn.rl = 3;
	msg.num_bytes = 1;
	msg.wbuf = NULL;
	ret = slim_do_transfer(ctrl, &txn);

clk_pause_ret:
	if (ret) {
		sched->clk_state = SLIM_CLK_ACTIVE;
	} else {
		sched->clk_state = SLIM_CLK_PAUSED;
		complete(&sched->pause_comp);
	}
	mutex_unlock(&sched->m_reconf);

	return ret;
}
EXPORT_SYMBOL_GPL(slim_ctrl_clk_pause);

Annotation

Implementation Notes