int mcp23s08_probe_one()

in pinctrl-mcp23s08.c [528:643]

• 89 lines of code
• 23 McCabe index (conditional complexity)

int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
		       unsigned int addr, unsigned int type, unsigned int base)
{
	int status, ret;
	bool mirror = false;
	bool open_drain = false;

	mutex_init(&mcp->lock);

	mcp->dev = dev;
	mcp->addr = addr;

	mcp->irq_active_high = false;
	mcp->irq_chip.name = dev_name(dev);
	mcp->irq_chip.irq_mask = mcp23s08_irq_mask;
	mcp->irq_chip.irq_unmask = mcp23s08_irq_unmask;
	mcp->irq_chip.irq_set_type = mcp23s08_irq_set_type;
	mcp->irq_chip.irq_bus_lock = mcp23s08_irq_bus_lock;
	mcp->irq_chip.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock;

	mcp->chip.direction_input = mcp23s08_direction_input;
	mcp->chip.get = mcp23s08_get;
	mcp->chip.direction_output = mcp23s08_direction_output;
	mcp->chip.set = mcp23s08_set;
#ifdef CONFIG_OF_GPIO
	mcp->chip.of_gpio_n_cells = 2;
#endif

	mcp->chip.base = base;
	mcp->chip.can_sleep = true;
	mcp->chip.parent = dev;
	mcp->chip.owner = THIS_MODULE;

	mcp->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);

	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
	 */

	ret = mcp_read(mcp, MCP_IOCON, &status);
	if (ret < 0)
		return dev_err_probe(dev, ret, "can't identify chip %d\n", addr);

	mcp->irq_controller =
		device_property_read_bool(dev, "interrupt-controller");
	if (mcp->irq && mcp->irq_controller) {
		mcp->irq_active_high =
			device_property_read_bool(dev,
					      "microchip,irq-active-high");

		mirror = device_property_read_bool(dev, "microchip,irq-mirror");
		open_drain = device_property_read_bool(dev, "drive-open-drain");
	}

	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror ||
	     mcp->irq_active_high || open_drain) {
		/* mcp23s17 has IOCON twice, make sure they are in sync */
		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
		status |= IOCON_HAEN | (IOCON_HAEN << 8);
		if (mcp->irq_active_high)
			status |= IOCON_INTPOL | (IOCON_INTPOL << 8);
		else
			status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));

		if (mirror)
			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);

		if (open_drain)
			status |= IOCON_ODR | (IOCON_ODR << 8);

		if (type == MCP_TYPE_S18 || type == MCP_TYPE_018)
			status |= IOCON_INTCC | (IOCON_INTCC << 8);

		ret = mcp_write(mcp, MCP_IOCON, status);
		if (ret < 0)
			return dev_err_probe(dev, ret, "can't write IOCON %d\n", addr);
	}

	if (mcp->irq && mcp->irq_controller) {
		struct gpio_irq_chip *girq = &mcp->chip.irq;

		girq->chip = &mcp->irq_chip;
		/* This will let us handle the parent IRQ in the driver */
		girq->parent_handler = NULL;
		girq->num_parents = 0;
		girq->parents = NULL;
		girq->default_type = IRQ_TYPE_NONE;
		girq->handler = handle_simple_irq;
		girq->threaded = true;
	}

	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
	if (ret < 0)
		return dev_err_probe(dev, ret, "can't add GPIO chip\n");

	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
	mcp->pinctrl_desc.npins = mcp->chip.ngpio;
	if (mcp->pinctrl_desc.npins == 8)
		mcp->pinctrl_desc.pins = mcp23x08_pins;
	else if (mcp->pinctrl_desc.npins == 16)
		mcp->pinctrl_desc.pins = mcp23x17_pins;
	mcp->pinctrl_desc.owner = THIS_MODULE;

	mcp->pctldev = devm_pinctrl_register(dev, &mcp->pinctrl_desc, mcp);
	if (IS_ERR(mcp->pctldev))
		return dev_err_probe(dev, PTR_ERR(mcp->pctldev), "can't register controller\n");

	if (mcp->irq) {
		ret = mcp23s08_irq_setup(mcp);
		if (ret)
			return dev_err_probe(dev, ret, "can't setup IRQ\n");
	}

	return 0;
}