static int abb5zes3_rtc_check_setup()

in rtc-ab-b5ze-s3.c [602:726]

• 82 lines of code
• 11 McCabe index (conditional complexity)

static int abb5zes3_rtc_check_setup(struct device *dev)
{
	struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;
	unsigned int reg;
	int ret;
	u8 mask;

	/*
	 * By default, the devices generates a 32.768KHz signal on IRQ#1 pin. It
	 * is disabled here to prevent polluting the interrupt line and
	 * uselessly triggering the IRQ handler we install for alarm and battery
	 * low events. Note: this is done before clearing int. status below
	 * in this function.
	 * We also disable all timers and set timer interrupt to permanent (not
	 * pulsed).
	 */
	mask = (ABB5ZES3_REG_TIM_CLK_TBC | ABB5ZES3_REG_TIM_CLK_TAC0 |
		ABB5ZES3_REG_TIM_CLK_TAC1 | ABB5ZES3_REG_TIM_CLK_COF0 |
		ABB5ZES3_REG_TIM_CLK_COF1 | ABB5ZES3_REG_TIM_CLK_COF2 |
		ABB5ZES3_REG_TIM_CLK_TBM | ABB5ZES3_REG_TIM_CLK_TAM);
	ret = regmap_update_bits(regmap, ABB5ZES3_REG_TIM_CLK, mask,
				 ABB5ZES3_REG_TIM_CLK_COF0 |
				 ABB5ZES3_REG_TIM_CLK_COF1 |
				 ABB5ZES3_REG_TIM_CLK_COF2);
	if (ret < 0) {
		dev_err(dev, "%s: unable to initialize clkout register (%d)\n",
			__func__, ret);
		return ret;
	}

	/*
	 * Each component of the alarm (MN, HR, DT, DW) can be enabled/disabled
	 * individually by clearing/setting MSB of each associated register. So,
	 * we set all alarm enable bits to disable current alarm setting.
	 */
	mask = (ABB5ZES3_REG_ALRM_MN_AE | ABB5ZES3_REG_ALRM_HR_AE |
		ABB5ZES3_REG_ALRM_DT_AE | ABB5ZES3_REG_ALRM_DW_AE);
	ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, mask);
	if (ret < 0) {
		dev_err(dev, "%s: unable to disable alarm setting (%d)\n",
			__func__, ret);
		return ret;
	}

	/* Set Control 1 register (RTC enabled, 24hr mode, all int. disabled) */
	mask = (ABB5ZES3_REG_CTRL1_CIE | ABB5ZES3_REG_CTRL1_AIE |
		ABB5ZES3_REG_CTRL1_SIE | ABB5ZES3_REG_CTRL1_PM |
		ABB5ZES3_REG_CTRL1_CAP | ABB5ZES3_REG_CTRL1_STOP);
	ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL1, mask, 0);
	if (ret < 0) {
		dev_err(dev, "%s: unable to initialize CTRL1 register (%d)\n",
			__func__, ret);
		return ret;
	}

	/*
	 * Set Control 2 register (timer int. disabled, alarm status cleared).
	 * WTAF is read-only and cleared automatically by reading the register.
	 */
	mask = (ABB5ZES3_REG_CTRL2_CTBIE | ABB5ZES3_REG_CTRL2_CTAIE |
		ABB5ZES3_REG_CTRL2_WTAIE | ABB5ZES3_REG_CTRL2_AF |
		ABB5ZES3_REG_CTRL2_SF | ABB5ZES3_REG_CTRL2_CTBF |
		ABB5ZES3_REG_CTRL2_CTAF);
	ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, 0);
	if (ret < 0) {
		dev_err(dev, "%s: unable to initialize CTRL2 register (%d)\n",
			__func__, ret);
		return ret;
	}

	/*
	 * Enable battery low detection function and battery switchover function
	 * (standard mode). Disable associated interrupts. Clear battery
	 * switchover flag but not battery low flag. The latter is checked
	 * later below.
	 */
	mask = (ABB5ZES3_REG_CTRL3_PM0  | ABB5ZES3_REG_CTRL3_PM1 |
		ABB5ZES3_REG_CTRL3_PM2  | ABB5ZES3_REG_CTRL3_BLIE |
		ABB5ZES3_REG_CTRL3_BSIE | ABB5ZES3_REG_CTRL3_BSF);
	ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3, mask, 0);
	if (ret < 0) {
		dev_err(dev, "%s: unable to initialize CTRL3 register (%d)\n",
			__func__, ret);
		return ret;
	}

	/* Check oscillator integrity flag */
	ret = regmap_read(regmap, ABB5ZES3_REG_RTC_SC, &reg);
	if (ret < 0) {
		dev_err(dev, "%s: unable to read osc. integrity flag (%d)\n",
			__func__, ret);
		return ret;
	}

	if (reg & ABB5ZES3_REG_RTC_SC_OSC) {
		dev_err(dev, "clock integrity not guaranteed. Osc. has stopped or has been interrupted.\n");
		dev_err(dev, "change battery (if not already done) and then set time to reset osc. failure flag.\n");
	}

	/*
	 * Check battery low flag at startup: this allows reporting battery
	 * is low at startup when IRQ line is not connected. Note: we record
	 * current status to avoid reenabling this interrupt later in probe
	 * function if battery is low.
	 */
	ret = regmap_read(regmap, ABB5ZES3_REG_CTRL3, &reg);
	if (ret < 0) {
		dev_err(dev, "%s: unable to read battery low flag (%d)\n",
			__func__, ret);
		return ret;
	}

	data->battery_low = reg & ABB5ZES3_REG_CTRL3_BLF;
	if (data->battery_low) {
		dev_err(dev, "RTC battery is low; please, consider changing it!\n");

		ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, false);
		if (ret)
			dev_err(dev, "%s: disabling battery low interrupt generation failed (%d)\n",
				__func__, ret);
	}

	return ret;
}