int sdw_bus_exit_clk_stop()

in bus.c [1062:1131]

• 45 lines of code
• 14 McCabe index (conditional complexity)

int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
{
	bool simple_clk_stop = true;
	struct sdw_slave *slave;
	bool is_slave = false;
	int ret;

	/*
	 * In order to save on transition time, de-prepare
	 * each Slave and then wait for all Slave(s) to be
	 * de-prepared after clock resume.
	 */
	list_for_each_entry(slave, &bus->slaves, node) {
		if (!slave->dev_num)
			continue;

		if (slave->status != SDW_SLAVE_ATTACHED &&
		    slave->status != SDW_SLAVE_ALERT)
			continue;

		/* Identify if Slave(s) are available on Bus */
		is_slave = true;

		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
						  SDW_CLK_PRE_DEPREPARE);
		if (ret < 0)
			dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);

		/* Only de-prepare a Slave device if needed */
		if (!slave->prop.simple_clk_stop_capable) {
			simple_clk_stop = false;

			ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
							 false);

			if (ret < 0)
				dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret);
		}
	}

	/* Skip remaining clock stop de-preparation if no Slave is attached */
	if (!is_slave)
		return 0;

	/*
	 * Don't wait for all Slaves to be ready if they follow the simple
	 * state machine
	 */
	if (!simple_clk_stop) {
		ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
		if (ret < 0)
			dev_warn(bus->dev, "clock stop deprepare wait failed:%d\n", ret);
	}

	list_for_each_entry(slave, &bus->slaves, node) {
		if (!slave->dev_num)
			continue;

		if (slave->status != SDW_SLAVE_ATTACHED &&
		    slave->status != SDW_SLAVE_ALERT)
			continue;

		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
						  SDW_CLK_POST_DEPREPARE);
		if (ret < 0)
			dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret);
	}

	return 0;
}