static int max3191x_probe()

in gpio-max3191x.c [359:444]

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

static int max3191x_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	struct max3191x_chip *max3191x;
	int n, ret;

	max3191x = devm_kzalloc(dev, sizeof(*max3191x), GFP_KERNEL);
	if (!max3191x)
		return -ENOMEM;
	spi_set_drvdata(spi, max3191x);

	max3191x->nchips = 1;
	device_property_read_u32(dev, "#daisy-chained-devices",
				 &max3191x->nchips);

	n = BITS_TO_LONGS(max3191x->nchips);
	max3191x->crc_error   = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);
	max3191x->undervolt1  = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);
	max3191x->undervolt2  = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);
	max3191x->overtemp    = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);
	max3191x->fault       = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);
	max3191x->xfer.rx_buf = devm_kcalloc(dev, max3191x->nchips,
								2, GFP_KERNEL);
	if (!max3191x->crc_error || !max3191x->undervolt1 ||
	    !max3191x->overtemp  || !max3191x->undervolt2 ||
	    !max3191x->fault     || !max3191x->xfer.rx_buf)
		return -ENOMEM;

	max3191x->modesel_pins = devm_gpiod_get_array_optional_count(dev,
				 "maxim,modesel", GPIOD_ASIS, max3191x->nchips);
	max3191x->fault_pins   = devm_gpiod_get_array_optional_count(dev,
				 "maxim,fault", GPIOD_IN, max3191x->nchips);
	max3191x->db0_pins     = devm_gpiod_get_array_optional_count(dev,
				 "maxim,db0", GPIOD_OUT_LOW, max3191x->nchips);
	max3191x->db1_pins     = devm_gpiod_get_array_optional_count(dev,
				 "maxim,db1", GPIOD_OUT_LOW, max3191x->nchips);

	max3191x->mode = device_property_read_bool(dev, "maxim,modesel-8bit")
				 ? STATUS_BYTE_DISABLED : STATUS_BYTE_ENABLED;
	if (max3191x->modesel_pins)
		gpiod_set_array_single_value_cansleep(
				 max3191x->modesel_pins->ndescs,
				 max3191x->modesel_pins->desc,
				 max3191x->modesel_pins->info, max3191x->mode);

	max3191x->ignore_uv = device_property_read_bool(dev,
						  "maxim,ignore-undervoltage");

	if (max3191x->db0_pins && max3191x->db1_pins &&
	    max3191x->db0_pins->ndescs != max3191x->db1_pins->ndescs) {
		dev_err(dev, "ignoring maxim,db*-gpios: array len mismatch\n");
		devm_gpiod_put_array(dev, max3191x->db0_pins);
		devm_gpiod_put_array(dev, max3191x->db1_pins);
		max3191x->db0_pins = NULL;
		max3191x->db1_pins = NULL;
	}

	max3191x->xfer.len = max3191x->nchips * max3191x_wordlen(max3191x);
	spi_message_init_with_transfers(&max3191x->mesg, &max3191x->xfer, 1);

	max3191x->gpio.label = spi->modalias;
	max3191x->gpio.owner = THIS_MODULE;
	max3191x->gpio.parent = dev;
	max3191x->gpio.base = -1;
	max3191x->gpio.ngpio = max3191x->nchips * MAX3191X_NGPIO;
	max3191x->gpio.can_sleep = true;

	max3191x->gpio.get_direction = max3191x_get_direction;
	max3191x->gpio.direction_input = max3191x_direction_input;
	max3191x->gpio.direction_output = max3191x_direction_output;
	max3191x->gpio.set = max3191x_set;
	max3191x->gpio.set_multiple = max3191x_set_multiple;
	max3191x->gpio.get = max3191x_get;
	max3191x->gpio.get_multiple = max3191x_get_multiple;
	max3191x->gpio.set_config = max3191x_set_config;

	mutex_init(&max3191x->lock);

	ret = gpiochip_add_data(&max3191x->gpio, max3191x);
	if (ret) {
		mutex_destroy(&max3191x->lock);
		return ret;
	}

	return 0;
}