static ssize_t alarms_store()

in slaves/w1_therm.c [1780:1877]

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

static ssize_t alarms_store(struct device *device,
	struct device_attribute *attr, const char *buf, size_t size)
{
	struct w1_slave *sl = dev_to_w1_slave(device);
	struct therm_info info;
	u8 new_config_register[3];	/* array of data to be written */
	int temp, ret;
	char *token = NULL;
	s8 tl, th;	/* 1 byte per value + temp ring order */
	char *p_args, *orig;

	p_args = orig = kmalloc(size, GFP_KERNEL);
	/* Safe string copys as buf is const */
	if (!p_args) {
		dev_warn(device,
			"%s: error unable to allocate memory %d\n",
			__func__, -ENOMEM);
		return size;
	}
	strcpy(p_args, buf);

	/* Split string using space char */
	token = strsep(&p_args, " ");

	if (!token)	{
		dev_info(device,
			"%s: error parsing args %d\n", __func__, -EINVAL);
		goto free_m;
	}

	/* Convert 1st entry to int */
	ret = kstrtoint (token, 10, &temp);
	if (ret) {
		dev_info(device,
			"%s: error parsing args %d\n", __func__, ret);
		goto free_m;
	}

	tl = int_to_short(temp);

	/* Split string using space char */
	token = strsep(&p_args, " ");
	if (!token)	{
		dev_info(device,
			"%s: error parsing args %d\n", __func__, -EINVAL);
		goto free_m;
	}
	/* Convert 2nd entry to int */
	ret = kstrtoint (token, 10, &temp);
	if (ret) {
		dev_info(device,
			"%s: error parsing args %d\n", __func__, ret);
		goto free_m;
	}

	/* Prepare to cast to short by eliminating out of range values */
	th = int_to_short(temp);

	/* Reorder if required th and tl */
	if (tl > th)
		swap(tl, th);

	/*
	 * Read the scratchpad to change only the required bits
	 * (th : byte 2 - tl: byte 3)
	 */
	ret = read_scratchpad(sl, &info);
	if (!ret) {
		new_config_register[0] = th;	/* Byte 2 */
		new_config_register[1] = tl;	/* Byte 3 */
		new_config_register[2] = info.rom[4];/* Byte 4 */
	} else {
		dev_info(device,
			"%s: error reading from the slave device %d\n",
			__func__, ret);
		goto free_m;
	}

	/* Write data in the device RAM */
	if (!SLAVE_SPECIFIC_FUNC(sl)) {
		dev_info(device,
			"%s: Device not supported by the driver %d\n",
			__func__, -ENODEV);
		goto free_m;
	}

	ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
	if (ret)
		dev_info(device,
			"%s: error writing to the slave device %d\n",
			__func__, ret);

free_m:
	/* free allocated memory */
	kfree(orig);

	return size;
}