1 // SPDX-License-Identifier: GPL-2.0-only
3  * Driver for the Epson RTC module RX-6110 SA
20 /* RX-6110 Register definitions */
104  * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
114 	 * The year in the RTC is a value between 0 and 99.  in rx6110_rtc_tm_to_data()
118 	if (tm->tm_year < 100 || tm->tm_year >= 200)  in rx6110_rtc_tm_to_data()
119 		return -EINVAL;  in rx6110_rtc_tm_to_data()
121 	data[RTC_SEC] = bin2bcd(tm->tm_sec);  in rx6110_rtc_tm_to_data()
122 	data[RTC_MIN] = bin2bcd(tm->tm_min);  in rx6110_rtc_tm_to_data()
123 	data[RTC_HOUR] = bin2bcd(tm->tm_hour);  in rx6110_rtc_tm_to_data()
124 	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));  in rx6110_rtc_tm_to_data()
125 	data[RTC_MDAY] = bin2bcd(tm->tm_mday);  in rx6110_rtc_tm_to_data()
126 	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);  in rx6110_rtc_tm_to_data()
127 	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);  in rx6110_rtc_tm_to_data()
133  * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
140 	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);  in rx6110_data_to_rtc_tm()
141 	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);  in rx6110_data_to_rtc_tm()
142 	/* only 24-hour clock */  in rx6110_data_to_rtc_tm()
143 	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);  in rx6110_data_to_rtc_tm()
144 	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);  in rx6110_data_to_rtc_tm()
145 	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);  in rx6110_data_to_rtc_tm()
146 	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;  in rx6110_data_to_rtc_tm()
147 	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;  in rx6110_data_to_rtc_tm()
152 	 * The year in the RTC is a value between 0 and 99.  in rx6110_data_to_rtc_tm()
156 	if (tm->tm_year < 100 || tm->tm_year >= 200)  in rx6110_data_to_rtc_tm()
157 		return -EINVAL;  in rx6110_data_to_rtc_tm()
163  * rx6110_set_time - set the current time in the rx6110 registers
168  * BUG: The HW assumes every year that is a multiple of 4 to be a leap
169  * year. Next time this is wrong is 2100, which will not be a leap year
171  * Note: If STOP is not set/cleared, the clock will start when the seconds
186 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,  in rx6110_set_time()
191 	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,  in rx6110_set_time()
197 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,  in rx6110_set_time()
203 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,  in rx6110_set_time()
210  * rx6110_get_time - get the current time from the rx6110 registers
221 	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);  in rx6110_get_time()
223 		return -EINVAL;  in rx6110_get_time()
225 	/* check for VLF Flag (set at power-on) */  in rx6110_get_time()
228 		return -EINVAL;  in rx6110_get_time()
232 	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,  in rx6110_get_time()
257  * rx6110_init - initialize the rx6110 registers
264 	struct rtc_device *rtc = rx6110->rtc;  in rx6110_init()
268 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,  in rx6110_init()
273 	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,  in rx6110_init()
278 	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);  in rx6110_init()
282 	/* check for VLF Flag (set at power-on) */  in rx6110_init()
284 		dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");  in rx6110_init()
288 		dev_warn(&rtc->dev, "An alarm may have been missed.\n");  in rx6110_init()
292 		dev_warn(&rtc->dev, "Periodic timer was detected\n");  in rx6110_init()
296 		dev_warn(&rtc->dev, "Update timer was detected\n");  in rx6110_init()
299 	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,  in rx6110_init()
321  * rx6110_probe - initialize rtc driver
329 	if ((spi->bits_per_word && spi->bits_per_word != 8) ||  in rx6110_probe()
330 	    (spi->max_speed_hz > 2000000) ||  in rx6110_probe()
331 	    (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) {  in rx6110_probe()
332 		dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",  in rx6110_probe()
333 			 spi->bits_per_word, spi->max_speed_hz, spi->mode);  in rx6110_probe()
334 		dev_warn(&spi->dev, "driving device in an unsupported mode");  in rx6110_probe()
337 	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);  in rx6110_probe()
339 		return -ENOMEM;  in rx6110_probe()
341 	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);  in rx6110_probe()
342 	if (IS_ERR(rx6110->regmap)) {  in rx6110_probe()
343 		dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");  in rx6110_probe()
344 		return PTR_ERR(rx6110->regmap);  in rx6110_probe()
349 	rx6110->rtc = devm_rtc_device_register(&spi->dev,  in rx6110_probe()
353 	if (IS_ERR(rx6110->rtc))  in rx6110_probe()
354 		return PTR_ERR(rx6110->rtc);  in rx6110_probe()
360 	rx6110->rtc->max_user_freq = 1;  in rx6110_probe()
389 MODULE_DESCRIPTION("RX-6110 SA RTC driver");