static int rs5c372_probe()

in rtc-rs5c372.c [615:732]

• 84 lines of code
• 24 McCabe index (conditional complexity)

static int rs5c372_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	int err = 0;
	int smbus_mode = 0;
	struct rs5c372 *rs5c372;

	dev_dbg(&client->dev, "%s\n", __func__);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
		/*
		 * If we don't have any master mode adapter, try breaking
		 * it down in to the barest of capabilities.
		 */
		if (i2c_check_functionality(client->adapter,
				I2C_FUNC_SMBUS_BYTE_DATA |
				I2C_FUNC_SMBUS_I2C_BLOCK))
			smbus_mode = 1;
		else {
			/* Still no good, give up */
			err = -ENODEV;
			goto exit;
		}
	}

	rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
				GFP_KERNEL);
	if (!rs5c372) {
		err = -ENOMEM;
		goto exit;
	}

	rs5c372->client = client;
	i2c_set_clientdata(client, rs5c372);
	if (client->dev.of_node)
		rs5c372->type = (enum rtc_type)
			of_device_get_match_data(&client->dev);
	else
		rs5c372->type = id->driver_data;

	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
	rs5c372->regs = &rs5c372->buf[1];
	rs5c372->smbus = smbus_mode;

	err = rs5c_get_regs(rs5c372);
	if (err < 0)
		goto exit;

	/* clock may be set for am/pm or 24 hr time */
	switch (rs5c372->type) {
	case rtc_rs5c372a:
	case rtc_rs5c372b:
		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
		 * so does periodic irq, except some 327a modes.
		 */
		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
			rs5c372->time24 = 1;
		break;
	case rtc_r2025sd:
	case rtc_r2221tl:
	case rtc_rv5c386:
	case rtc_rv5c387a:
		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
			rs5c372->time24 = 1;
		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
		 * irq, on both 386 and 387
		 */
		break;
	default:
		dev_err(&client->dev, "unknown RTC type\n");
		goto exit;
	}

	/* if the oscillator lost power and no other software (like
	 * the bootloader) set it up, do it here.
	 *
	 * The R2025S/D does this a little differently than the other
	 * parts, so we special case that..
	 */
	err = rs5c_oscillator_setup(rs5c372);
	if (unlikely(err < 0)) {
		dev_err(&client->dev, "setup error\n");
		goto exit;
	}

	dev_info(&client->dev, "%s found, %s\n",
			({ char *s; switch (rs5c372->type) {
			case rtc_r2025sd:	s = "r2025sd"; break;
			case rtc_r2221tl:	s = "r2221tl"; break;
			case rtc_rs5c372a:	s = "rs5c372a"; break;
			case rtc_rs5c372b:	s = "rs5c372b"; break;
			case rtc_rv5c386:	s = "rv5c386"; break;
			case rtc_rv5c387a:	s = "rv5c387a"; break;
			default:		s = "chip"; break;
			}; s;}),
			rs5c372->time24 ? "24hr" : "am/pm"
			);

	/* REVISIT use client->irq to register alarm irq ... */
	rs5c372->rtc = devm_rtc_device_register(&client->dev,
					rs5c372_driver.driver.name,
					&rs5c372_rtc_ops, THIS_MODULE);

	if (IS_ERR(rs5c372->rtc)) {
		err = PTR_ERR(rs5c372->rtc);
		goto exit;
	}

	err = rs5c_sysfs_register(&client->dev);
	if (err)
		goto exit;

	return 0;

exit:
	return err;
}