static ssize_t lp5523_selftest()

in leds-lp5523.c [577:662]

• 62 lines of code
• 15 McCabe index (conditional complexity)

static ssize_t lp5523_selftest(struct device *dev,
			       struct device_attribute *attr,
			       char *buf)
{
	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
	struct lp55xx_chip *chip = led->chip;
	struct lp55xx_platform_data *pdata = chip->pdata;
	int i, ret, pos = 0;
	u8 status, adc, vdd;

	mutex_lock(&chip->lock);

	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
	if (ret < 0)
		goto fail;

	/* Check that ext clock is really in use if requested */
	if (pdata->clock_mode == LP55XX_CLOCK_EXT) {
		if  ((status & LP5523_EXT_CLK_USED) == 0)
			goto fail;
	}

	/* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
	lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16);
	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
	if (ret < 0)
		goto fail;

	if (!(status & LP5523_LEDTEST_DONE))
		usleep_range(3000, 6000); /* Was not ready. Wait little bit */

	ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &vdd);
	if (ret < 0)
		goto fail;

	vdd--;	/* There may be some fluctuation in measurement */

	for (i = 0; i < LP5523_MAX_LEDS; i++) {
		/* Skip non-existing channels */
		if (pdata->led_config[i].led_current == 0)
			continue;

		/* Set default current */
		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
			pdata->led_config[i].led_current);

		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0xff);
		/* let current stabilize 2 - 4ms before measurements start */
		usleep_range(2000, 4000);
		lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL,
			     LP5523_EN_LEDTEST | i);
		/* ADC conversion time is 2.7 ms typically */
		usleep_range(3000, 6000);
		ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
		if (ret < 0)
			goto fail;

		if (!(status & LP5523_LEDTEST_DONE))
			usleep_range(3000, 6000);/* Was not ready. Wait. */

		ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &adc);
		if (ret < 0)
			goto fail;

		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
			pos += sprintf(buf + pos, "LED %d FAIL\n", i);

		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0x00);

		/* Restore current */
		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
			led->led_current);
		led++;
	}
	if (pos == 0)
		pos = sprintf(buf, "OK\n");
	goto release_lock;
fail:
	pos = sprintf(buf, "FAIL\n");

release_lock:
	mutex_unlock(&chip->lock);

	return pos;
}