static int pca953x_probe()

in gpio-pca953x.c [943:1084]

• 93 lines of code
• 18 McCabe index (conditional complexity)

static int pca953x_probe(struct i2c_client *client,
			 const struct i2c_device_id *i2c_id)
{
	struct pca953x_platform_data *pdata;
	struct pca953x_chip *chip;
	int irq_base = 0;
	int ret;
	u32 invert = 0;
	struct regulator *reg;
	const struct regmap_config *regmap_config;

	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;

	pdata = dev_get_platdata(&client->dev);
	if (pdata) {
		irq_base = pdata->irq_base;
		chip->gpio_start = pdata->gpio_base;
		invert = pdata->invert;
		chip->names = pdata->names;
	} else {
		struct gpio_desc *reset_gpio;

		chip->gpio_start = -1;
		irq_base = 0;

		/*
		 * See if we need to de-assert a reset pin.
		 *
		 * There is no known ACPI-enabled platforms that are
		 * using "reset" GPIO. Otherwise any of those platform
		 * must use _DSD method with corresponding property.
		 */
		reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
						     GPIOD_OUT_LOW);
		if (IS_ERR(reset_gpio))
			return PTR_ERR(reset_gpio);
	}

	chip->client = client;

	reg = devm_regulator_get(&client->dev, "vcc");
	if (IS_ERR(reg))
		return dev_err_probe(&client->dev, PTR_ERR(reg), "reg get err\n");

	ret = regulator_enable(reg);
	if (ret) {
		dev_err(&client->dev, "reg en err: %d\n", ret);
		return ret;
	}
	chip->regulator = reg;

	if (i2c_id) {
		chip->driver_data = i2c_id->driver_data;
	} else {
		const void *match;

		match = device_get_match_data(&client->dev);
		if (!match) {
			ret = -ENODEV;
			goto err_exit;
		}

		chip->driver_data = (uintptr_t)match;
	}

	i2c_set_clientdata(client, chip);

	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);

	if (NBANK(chip) > 2 || PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE) {
		dev_info(&client->dev, "using AI\n");
		regmap_config = &pca953x_ai_i2c_regmap;
	} else {
		dev_info(&client->dev, "using no AI\n");
		regmap_config = &pca953x_i2c_regmap;
	}

	chip->regmap = devm_regmap_init_i2c(client, regmap_config);
	if (IS_ERR(chip->regmap)) {
		ret = PTR_ERR(chip->regmap);
		goto err_exit;
	}

	regcache_mark_dirty(chip->regmap);

	mutex_init(&chip->i2c_lock);
	/*
	 * In case we have an i2c-mux controlled by a GPIO provided by an
	 * expander using the same driver higher on the device tree, read the
	 * i2c adapter nesting depth and use the retrieved value as lockdep
	 * subclass for chip->i2c_lock.
	 *
	 * REVISIT: This solution is not complete. It protects us from lockdep
	 * false positives when the expander controlling the i2c-mux is on
	 * a different level on the device tree, but not when it's on the same
	 * level on a different branch (in which case the subclass number
	 * would be the same).
	 *
	 * TODO: Once a correct solution is developed, a similar fix should be
	 * applied to all other i2c-controlled GPIO expanders (and potentially
	 * regmap-i2c).
	 */
	lockdep_set_subclass(&chip->i2c_lock,
			     i2c_adapter_depth(client->adapter));

	/* initialize cached registers from their original values.
	 * we can't share this chip with another i2c master.
	 */

	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
		chip->regs = &pca953x_regs;
		ret = device_pca95xx_init(chip, invert);
	} else {
		chip->regs = &pca957x_regs;
		ret = device_pca957x_init(chip, invert);
	}
	if (ret)
		goto err_exit;

	ret = pca953x_irq_setup(chip, irq_base);
	if (ret)
		goto err_exit;

	ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
	if (ret)
		goto err_exit;

	if (pdata && pdata->setup) {
		ret = pdata->setup(client, chip->gpio_chip.base,
				   chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0)
			dev_warn(&client->dev, "setup failed, %d\n", ret);
	}

	return 0;

err_exit:
	regulator_disable(chip->regulator);
	return ret;
}