static int pca955x_probe()

in leds-pca955x.c [482:681]

• 163 lines of code
• 33 McCabe index (conditional complexity)

static int pca955x_probe(struct i2c_client *client)
{
	struct pca955x *pca955x;
	struct pca955x_led *pca955x_led;
	struct pca955x_chipdef *chip;
	struct led_classdev *led;
	struct led_init_data init_data;
	struct i2c_adapter *adapter;
	int i, err;
	struct pca955x_platform_data *pdata;
	int ngpios = 0;
	bool set_default_label = false;
	bool keep_pwm = false;
	char default_label[8];
	enum pca955x_type chip_type;
	const void *md = device_get_match_data(&client->dev);

	if (md) {
		chip_type = (enum pca955x_type)md;
	} else {
		const struct i2c_device_id *id = i2c_match_id(pca955x_id,
							      client);

		if (id) {
			chip_type = (enum pca955x_type)id->driver_data;
		} else {
			dev_err(&client->dev, "unknown chip\n");
			return -ENODEV;
		}
	}

	chip = &pca955x_chipdefs[chip_type];
	adapter = client->adapter;
	pdata = dev_get_platdata(&client->dev);
	if (!pdata) {
		pdata =	pca955x_get_pdata(client, chip);
		if (IS_ERR(pdata))
			return PTR_ERR(pdata);
	}

	/* Make sure the slave address / chip type combo given is possible */
	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
	    chip->slv_addr) {
		dev_err(&client->dev, "invalid slave address %02x\n",
			client->addr);
		return -ENODEV;
	}

	dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
		 "slave address 0x%02x\n", client->name, chip->bits,
		 client->addr);

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -EIO;

	if (pdata->num_leds != chip->bits) {
		dev_err(&client->dev,
			"board info claims %d LEDs on a %d-bit chip\n",
			pdata->num_leds, chip->bits);
		return -ENODEV;
	}

	pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
	if (!pca955x)
		return -ENOMEM;

	pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
				     sizeof(*pca955x_led), GFP_KERNEL);
	if (!pca955x->leds)
		return -ENOMEM;

	i2c_set_clientdata(client, pca955x);

	mutex_init(&pca955x->lock);
	pca955x->client = client;
	pca955x->chipdef = chip;

	init_data.devname_mandatory = false;
	init_data.devicename = "pca955x";

	for (i = 0; i < chip->bits; i++) {
		pca955x_led = &pca955x->leds[i];
		pca955x_led->led_num = i;
		pca955x_led->pca955x = pca955x;
		pca955x_led->type = pdata->leds[i].type;

		switch (pca955x_led->type) {
		case PCA955X_TYPE_NONE:
			break;
		case PCA955X_TYPE_GPIO:
			ngpios++;
			break;
		case PCA955X_TYPE_LED:
			led = &pca955x_led->led_cdev;
			led->brightness_set_blocking = pca955x_led_set;
			led->brightness_get = pca955x_led_get;

			if (pdata->leds[i].default_state ==
			    LEDS_GPIO_DEFSTATE_OFF) {
				err = pca955x_led_set(led, LED_OFF);
				if (err)
					return err;
			} else if (pdata->leds[i].default_state ==
				   LEDS_GPIO_DEFSTATE_ON) {
				err = pca955x_led_set(led, LED_FULL);
				if (err)
					return err;
			}

			init_data.fwnode = pdata->leds[i].fwnode;

			if (is_of_node(init_data.fwnode)) {
				if (to_of_node(init_data.fwnode)->name[0] ==
				    '\0')
					set_default_label = true;
				else
					set_default_label = false;
			} else {
				set_default_label = true;
			}

			if (set_default_label) {
				snprintf(default_label, sizeof(default_label),
					 "%d", i);
				init_data.default_label = default_label;
			} else {
				init_data.default_label = NULL;
			}

			err = devm_led_classdev_register_ext(&client->dev, led,
							     &init_data);
			if (err)
				return err;

			/*
			 * For default-state == "keep", let the core update the
			 * brightness from the hardware, then check the
			 * brightness to see if it's using PWM1. If so, PWM1
			 * should not be written below.
			 */
			if (pdata->leds[i].default_state ==
			    LEDS_GPIO_DEFSTATE_KEEP) {
				if (led->brightness != LED_FULL &&
				    led->brightness != LED_OFF &&
				    led->brightness != LED_HALF)
					keep_pwm = true;
			}
		}
	}

	/* PWM0 is used for half brightness or 50% duty cycle */
	err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
	if (err)
		return err;

	if (!keep_pwm) {
		/* PWM1 is used for variable brightness, default to OFF */
		err = pca955x_write_pwm(client, 1, 0);
		if (err)
			return err;
	}

	/* Set to fast frequency so we do not see flashing */
	err = pca955x_write_psc(client, 0, 0);
	if (err)
		return err;
	err = pca955x_write_psc(client, 1, 0);
	if (err)
		return err;

#ifdef CONFIG_LEDS_PCA955X_GPIO
	if (ngpios) {
		pca955x->gpio.label = "gpio-pca955x";
		pca955x->gpio.direction_input = pca955x_gpio_direction_input;
		pca955x->gpio.direction_output = pca955x_gpio_direction_output;
		pca955x->gpio.set = pca955x_gpio_set_value;
		pca955x->gpio.get = pca955x_gpio_get_value;
		pca955x->gpio.request = pca955x_gpio_request_pin;
		pca955x->gpio.can_sleep = 1;
		pca955x->gpio.base = -1;
		pca955x->gpio.ngpio = ngpios;
		pca955x->gpio.parent = &client->dev;
		pca955x->gpio.owner = THIS_MODULE;

		err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
					     pca955x);
		if (err) {
			/* Use data->gpio.dev as a flag for freeing gpiochip */
			pca955x->gpio.parent = NULL;
			dev_warn(&client->dev, "could not add gpiochip\n");
			return err;
		}
		dev_info(&client->dev, "gpios %i...%i\n",
			 pca955x->gpio.base, pca955x->gpio.base +
			 pca955x->gpio.ngpio - 1);
	}
#endif

	return 0;
}