static int envctrl_probe()

in char/envctrl.c [1024:1098]

• 54 lines of code
• 13 McCabe index (conditional complexity)

static int envctrl_probe(struct platform_device *op)
{
	struct device_node *dp;
	int index, err;

	if (i2c)
		return -EINVAL;

	i2c = of_ioremap(&op->resource[0], 0, 0x2, DRIVER_NAME);
	if (!i2c)
		return -ENOMEM;

	index = 0;
	dp = op->dev.of_node->child;
	while (dp) {
		if (of_node_name_eq(dp, "gpio")) {
			i2c_childlist[index].i2ctype = I2C_GPIO;
			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
		} else if (of_node_name_eq(dp, "adc")) {
			i2c_childlist[index].i2ctype = I2C_ADC;
			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
		}

		dp = dp->sibling;
	}

	/* Set device address. */
	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);

	/* Set system clock and SCL frequencies. */ 
	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);

	/* Enable serial interface. */
	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
	udelay(200);

	/* Register the device as a minor miscellaneous device. */
	err = misc_register(&envctrl_dev);
	if (err) {
		printk(KERN_ERR PFX "Unable to get misc minor %d\n",
		       envctrl_dev.minor);
		goto out_iounmap;
	}

	/* Note above traversal routine post-incremented 'i' to accommodate 
	 * a next child device, so we decrement before reverse-traversal of
	 * child devices.
	 */
	printk(KERN_INFO PFX "Initialized ");
	for (--index; index >= 0; --index) {
		printk("[%s 0x%lx]%s", 
			(I2C_ADC == i2c_childlist[index].i2ctype) ? "adc" : 
			((I2C_GPIO == i2c_childlist[index].i2ctype) ? "gpio" : "unknown"), 
			i2c_childlist[index].addr, (0 == index) ? "\n" : " ");
	}

	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
	if (IS_ERR(kenvctrld_task)) {
		err = PTR_ERR(kenvctrld_task);
		goto out_deregister;
	}

	return 0;

out_deregister:
	misc_deregister(&envctrl_dev);
out_iounmap:
	of_iounmap(&op->resource[0], i2c, 0x2);
	for (index = 0; index < ENVCTRL_MAX_CPU * 2; index++)
		kfree(i2c_childlist[index].tables);

	return err;
}