1 // SPDX-License-Identifier: GPL-2.0-only
3  * Driver for the Epson RTC module RX-6110 SA
19 /* RX-6110 Register definitions */
103  * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
113 	 * The year in the RTC is a value between 0 and 99.  in rx6110_rtc_tm_to_data()
117 	if (tm->tm_year < 100 || tm->tm_year >= 200)  in rx6110_rtc_tm_to_data()
118 		return -EINVAL;  in rx6110_rtc_tm_to_data()
120 	data[RTC_SEC] = bin2bcd(tm->tm_sec);  in rx6110_rtc_tm_to_data()
121 	data[RTC_MIN] = bin2bcd(tm->tm_min);  in rx6110_rtc_tm_to_data()
122 	data[RTC_HOUR] = bin2bcd(tm->tm_hour);  in rx6110_rtc_tm_to_data()
123 	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));  in rx6110_rtc_tm_to_data()
124 	data[RTC_MDAY] = bin2bcd(tm->tm_mday);  in rx6110_rtc_tm_to_data()
125 	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);  in rx6110_rtc_tm_to_data()
126 	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);  in rx6110_rtc_tm_to_data()
132  * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
139 	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);  in rx6110_data_to_rtc_tm()
140 	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);  in rx6110_data_to_rtc_tm()
141 	/* only 24-hour clock */  in rx6110_data_to_rtc_tm()
142 	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);  in rx6110_data_to_rtc_tm()
143 	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);  in rx6110_data_to_rtc_tm()
144 	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);  in rx6110_data_to_rtc_tm()
145 	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;  in rx6110_data_to_rtc_tm()
146 	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;  in rx6110_data_to_rtc_tm()
151 	 * The year in the RTC is a value between 0 and 99.  in rx6110_data_to_rtc_tm()
155 	if (tm->tm_year < 100 || tm->tm_year >= 200)  in rx6110_data_to_rtc_tm()
156 		return -EINVAL;  in rx6110_data_to_rtc_tm()
162  * rx6110_set_time - set the current time in the rx6110 registers
167  * BUG: The HW assumes every year that is a multiple of 4 to be a leap
168  * year. Next time this is wrong is 2100, which will not be a leap year
170  * Note: If STOP is not set/cleared, the clock will start when the seconds
185 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,  in rx6110_set_time()
190 	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,  in rx6110_set_time()
196 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,  in rx6110_set_time()
202 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,  in rx6110_set_time()
209  * rx6110_get_time - get the current time from the rx6110 registers
220 	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);  in rx6110_get_time()
222 		return -EINVAL;  in rx6110_get_time()
224 	/* check for VLF Flag (set at power-on) */  in rx6110_get_time()
227 		return -EINVAL;  in rx6110_get_time()
231 	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,  in rx6110_get_time()
256  * rx6110_init - initialize the rx6110 registers
263 	struct rtc_device *rtc = rx6110->rtc;  in rx6110_init()
267 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,  in rx6110_init()
272 	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,  in rx6110_init()
277 	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);  in rx6110_init()
281 	/* check for VLF Flag (set at power-on) */  in rx6110_init()
283 		dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");  in rx6110_init()
287 		dev_warn(&rtc->dev, "An alarm may have been missed.\n");  in rx6110_init()
291 		dev_warn(&rtc->dev, "Periodic timer was detected\n");  in rx6110_init()
295 		dev_warn(&rtc->dev, "Update timer was detected\n");  in rx6110_init()
298 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,  in rx6110_init()
316 	rx6110->rtc = devm_rtc_device_register(dev,  in rx6110_probe()
320 	if (IS_ERR(rx6110->rtc))  in rx6110_probe()
321 		return PTR_ERR(rx6110->rtc);  in rx6110_probe()
327 	rx6110->rtc->max_user_freq = 1;  in rx6110_probe()
341  * rx6110_spi_probe - initialize rtc driver
348 	if ((spi->bits_per_word && spi->bits_per_word != 8) ||  in rx6110_spi_probe()
349 	    (spi->max_speed_hz > 2000000) ||  in rx6110_spi_probe()
350 	    (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) {  in rx6110_spi_probe()
351 		dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",  in rx6110_spi_probe()
352 			 spi->bits_per_word, spi->max_speed_hz, spi->mode);  in rx6110_spi_probe()
353 		dev_warn(&spi->dev, "driving device in an unsupported mode");  in rx6110_spi_probe()
356 	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);  in rx6110_spi_probe()
358 		return -ENOMEM;  in rx6110_spi_probe()
360 	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);  in rx6110_spi_probe()
361 	if (IS_ERR(rx6110->regmap)) {  in rx6110_spi_probe()
362 		dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");  in rx6110_spi_probe()
363 		return PTR_ERR(rx6110->regmap);  in rx6110_spi_probe()
368 	return rx6110_probe(rx6110, &spi->dev);  in rx6110_spi_probe()
422 	struct i2c_adapter *adapter = client->adapter;  in rx6110_i2c_probe()
427 		dev_err(&adapter->dev,  in rx6110_i2c_probe()
429 		return -EIO;  in rx6110_i2c_probe()
432 	rx6110 = devm_kzalloc(&client->dev, sizeof(*rx6110), GFP_KERNEL);  in rx6110_i2c_probe()
434 		return -ENOMEM;  in rx6110_i2c_probe()
436 	rx6110->regmap = devm_regmap_init_i2c(client, &regmap_i2c_config);  in rx6110_i2c_probe()
437 	if (IS_ERR(rx6110->regmap)) {  in rx6110_i2c_probe()
438 		dev_err(&client->dev, "regmap init failed for rtc rx6110\n");  in rx6110_i2c_probe()
439 		return PTR_ERR(rx6110->regmap);  in rx6110_i2c_probe()
444 	return rx6110_probe(rx6110, &client->dev);  in rx6110_i2c_probe()
512 MODULE_DESCRIPTION("RX-6110 SA RTC driver");