Re: [PATCH v3 2/2] rtc: max31329: Add Maxim max31329 real time clock

[Alexandre Belloni]

Hello,

I have a few small comments:

On 24/09/2022 00:23:58+0530, Jagath Jog J wrote:
> +static int max31329_get_osc_status(struct device *dev)

This function should be folded in its only call site, this will reduce
the size of the code.

> +{
> +	struct max31329_data *max31329 = dev_get_drvdata(dev);
> +	unsigned int status;
> +	int ret;
> +
> +	ret = regmap_read(max31329->regmap, MAX31329_STATUS_REG, &status);
> +	if (ret)
> +		return ret;
> +
> +	if (status & MAX31329_STATUS_OSF)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +

[...]

> +static int max31329_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct max31329_data *max31329 = dev_get_drvdata(dev);
> +	const struct rtc_time *tm = &alrm->time;
> +	u8 regs[6], year;
> +	int ret;
> +
> +	regs[REG_TO_OFFSET(MAX31329_SECONDS_REG)] = bin2bcd(tm->tm_sec) & 0x7F;
> +	regs[REG_TO_OFFSET(MAX31329_MINUTES_REG)] = bin2bcd(tm->tm_min) & 0x7f;
> +	regs[REG_TO_OFFSET(MAX31329_HOURS_REG)] = bin2bcd(tm->tm_hour) & 0x3f;
> +	regs[REG_TO_OFFSET(MAX31329_DATE_REG) - 1] = bin2bcd(tm->tm_mday) & 0x3f;
> +	regs[REG_TO_OFFSET(MAX31329_MONTH_REG) - 1] = bin2bcd(tm->tm_mon + 1) & 0x1f;
> +
> +	if (tm->tm_year >= 200)
> +		return -EINVAL;
> +
This check is unnecessary.

> +	year = bin2bcd(tm->tm_year - 100);
> +	regs[REG_TO_OFFSET(MAX31329_YEAR_REG) - 1] = year;
> +
> +	ret = regmap_bulk_write(max31329->regmap, MAX31329_ALM1_SEC_REG, regs,
> +				MAX31329_ALM1_SEC_LEN);
> +	if (ret)
> +		return ret;
> +
> +	return max31329_alarm_irq_enable(dev, alrm->enabled);
> +}

[...]

> +static int max31329_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
> +				    unsigned long parent_rate)
> +{
> +	struct max31329_data *max31329 = clkout_hw_to_max31329(hw);
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
> +		if (rate == clkout_rates[i])
> +			return regmap_update_bits(max31329->regmap,
> +						  MAX31329_RTC_CONFIG2_REG,
> +						  MAX31329_RTC_CFG2_CLKOHZ_MSK,
> +						  FIELD_PREP(MAX31329_RTC_CFG2_CLKOHZ_MSK,
> +							     i));

Doesn't that i fit on the previous line?

> +	return -EINVAL;
> +}
> +
> +static int max31329_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)

Doesn't that fit on one line?

> +{
> +	struct max31329_data *max31329;
> +	int ret;
> +	struct nvmem_config nvmem_cfg = {
> +		.name = "max31329_nvram",
> +		.word_size = 1,
> +		.stride = 1,
> +		.size = 64,
> +		.type = NVMEM_TYPE_BATTERY_BACKED,
> +		.reg_read = max31329_nvram_read,
> +		.reg_write = max31329_nvram_write,
> +	};
> +
> +	max31329 = devm_kzalloc(&client->dev, sizeof(*max31329), GFP_KERNEL);
> +	if (!max31329)
> +		return -ENOMEM;
> +
> +	max31329->regmap = devm_regmap_init_i2c(client, &config);
> +	if (IS_ERR(max31329->regmap))
> +		return PTR_ERR(max31329->regmap);
> +
> +	dev_set_drvdata(&client->dev, max31329);
> +
> +	max31329->rtc = devm_rtc_allocate_device(&client->dev);
> +	if (IS_ERR(max31329->rtc))
> +		return PTR_ERR(max31329->rtc);
> +
> +	max31329->rtc->ops = &max31329_rtc_ops;
> +	max31329->irq = client->irq;
> +	max31329->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
> +	max31329->rtc->range_max = RTC_TIMESTAMP_END_2199;
> +
> +	if (max31329->irq) {
> +		ret = devm_request_threaded_irq(&client->dev, max31329->irq,
> +						NULL, max31329_irq_handler,
> +						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +						"max31329", &client->dev);
> +		if (ret)
> +			return ret;
> +	} else {
> +		clear_bit(RTC_FEATURE_ALARM, max31329->rtc->features);
> +		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, max31329->rtc->features);
> +	}
> +
> +	if (max31329->irq || device_property_read_bool(&client->dev,
> +						       "wakeup-source"))
> +		device_init_wakeup(&client->dev, true);
> +
> +	ret = devm_rtc_register_device(max31329->rtc);
> +	if (ret)
> +		return ret;
> +
> +	max31329_trickle_config(&client->dev);
> +
> +	nvmem_cfg.priv = max31329->regmap;
> +	devm_rtc_nvmem_register(max31329->rtc, &nvmem_cfg);
> +
> +#ifdef CONFIG_COMMON_CLK
> +	max31329_clkout_register_clk(max31329, client);
> +#endif
> +
> +	return 0;
> +}
> +
> +static const __maybe_unused struct of_device_id max31329_of_match[] = {
> +	{ .compatible = "maxim,max31329", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, max31329_of_match);
> +
> +static struct i2c_driver max31329_driver = {
> +	.driver = {
> +		.name = "rtc-max31329",
> +		.of_match_table = of_match_ptr(max31329_of_match),
> +	},
> +	.probe = max31329_probe,
> +};
> +module_i2c_driver(max31329_driver);
> +
> +MODULE_AUTHOR("Jagath Jog J <jagathjog1996@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Maxim MAX31329 RTC driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.17.1
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com