static int ds1343_probe()

in rtc-ds1343.c [344:435]

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

static int ds1343_probe(struct spi_device *spi)
{
	struct ds1343_priv *priv;
	struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
					.write_flag_mask = 0x80, };
	unsigned int data;
	int res;
	struct nvmem_config nvmem_cfg = {
		.name = "ds1343-",
		.word_size = 1,
		.stride = 1,
		.size = DS1343_NVRAM_LEN,
		.reg_read = ds1343_nvram_read,
		.reg_write = ds1343_nvram_write,
	};

	priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	/* RTC DS1347 works in spi mode 3 and
	 * its chip select is active high. Active high should be defined as
	 * "inverse polarity" as GPIO-based chip selects can be logically
	 * active high but inverted by the GPIO library.
	 */
	spi->mode |= SPI_MODE_3;
	spi->mode ^= SPI_CS_HIGH;
	spi->bits_per_word = 8;
	res = spi_setup(spi);
	if (res)
		return res;

	spi_set_drvdata(spi, priv);

	priv->map = devm_regmap_init_spi(spi, &config);

	if (IS_ERR(priv->map)) {
		dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
		return PTR_ERR(priv->map);
	}

	res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
	if (res)
		return res;

	regmap_read(priv->map, DS1343_CONTROL_REG, &data);
	data |= DS1343_INTCN;
	data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
	regmap_write(priv->map, DS1343_CONTROL_REG, data);

	regmap_read(priv->map, DS1343_STATUS_REG, &data);
	data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
	regmap_write(priv->map, DS1343_STATUS_REG, data);

	priv->rtc = devm_rtc_allocate_device(&spi->dev);
	if (IS_ERR(priv->rtc))
		return PTR_ERR(priv->rtc);

	priv->rtc->ops = &ds1343_rtc_ops;
	priv->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	priv->rtc->range_max = RTC_TIMESTAMP_END_2099;

	res = rtc_add_group(priv->rtc, &ds1343_attr_group);
	if (res)
		dev_err(&spi->dev,
			"unable to create sysfs entries for rtc ds1343\n");

	res = devm_rtc_register_device(priv->rtc);
	if (res)
		return res;

	nvmem_cfg.priv = priv;
	devm_rtc_nvmem_register(priv->rtc, &nvmem_cfg);

	priv->irq = spi->irq;

	if (priv->irq >= 0) {
		res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
						ds1343_thread, IRQF_ONESHOT,
						"ds1343", priv);
		if (res) {
			priv->irq = -1;
			dev_err(&spi->dev,
				"unable to request irq for rtc ds1343\n");
		} else {
			device_init_wakeup(&spi->dev, true);
			dev_pm_set_wake_irq(&spi->dev, spi->irq);
		}
	}

	return 0;
}