1 // SPDX-License-Identifier: GPL-2.0-only
3  * rtc-ds1390.c -- driver for the Dallas/Maxim DS1390/93/94 SPI RTC
10  * (alarms, trickle charger, different control registers) are unavailable.
74 		return -EINVAL;  in ds1390_get_reg()
77 	chip->txrx_buf[0] = address & 0x7f;  in ds1390_get_reg()
79 	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 1);  in ds1390_get_reg()
83 	*data = chip->txrx_buf[0];  in ds1390_get_reg()
93 	if (of_property_read_u32(spi->dev.of_node, "trickle-resistor-ohms",  in ds1390_trickle_of_init()
99 	if (of_property_read_bool(spi->dev.of_node, "trickle-diode-disable"))  in ds1390_trickle_of_init()
116 		dev_warn(&spi->dev,  in ds1390_trickle_of_init()
121 	ds1390_set_reg(&spi->dev, DS1390_REG_TRICKLE, value);  in ds1390_trickle_of_init()
134 	chip->txrx_buf[0] = DS1390_REG_SECONDS;  in ds1390_read_time()
137 	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 8);  in ds1390_read_time()
143 	dt->tm_sec	= bcd2bin(chip->txrx_buf[0]);  in ds1390_read_time()
144 	dt->tm_min	= bcd2bin(chip->txrx_buf[1]);  in ds1390_read_time()
145 	dt->tm_hour	= bcd2bin(chip->txrx_buf[2]);  in ds1390_read_time()
146 	dt->tm_wday	= bcd2bin(chip->txrx_buf[3]);  in ds1390_read_time()
147 	dt->tm_mday	= bcd2bin(chip->txrx_buf[4]);  in ds1390_read_time()
149 	dt->tm_mon	= bcd2bin(chip->txrx_buf[5] & 0x7f) - 1;  in ds1390_read_time()
151 	dt->tm_year = bcd2bin(chip->txrx_buf[6]) + ((chip->txrx_buf[5] & 0x80) ? 100 : 0);  in ds1390_read_time()
162 	chip->txrx_buf[0] = DS1390_REG_SECONDS | 0x80;  in ds1390_set_time()
163 	chip->txrx_buf[1] = bin2bcd(dt->tm_sec);  in ds1390_set_time()
164 	chip->txrx_buf[2] = bin2bcd(dt->tm_min);  in ds1390_set_time()
165 	chip->txrx_buf[3] = bin2bcd(dt->tm_hour);  in ds1390_set_time()
166 	chip->txrx_buf[4] = bin2bcd(dt->tm_wday);  in ds1390_set_time()
167 	chip->txrx_buf[5] = bin2bcd(dt->tm_mday);  in ds1390_set_time()
168 	chip->txrx_buf[6] = bin2bcd(dt->tm_mon + 1) |  in ds1390_set_time()
169 				((dt->tm_year > 99) ? 0x80 : 0x00);  in ds1390_set_time()
170 	chip->txrx_buf[7] = bin2bcd(dt->tm_year % 100);  in ds1390_set_time()
173 	return spi_write_then_read(spi, chip->txrx_buf, 8, NULL, 0);  in ds1390_set_time()
187 	spi->mode = SPI_MODE_3;  in ds1390_probe()
188 	spi->bits_per_word = 8;  in ds1390_probe()
191 	chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL);  in ds1390_probe()
193 		return -ENOMEM;  in ds1390_probe()
197 	res = ds1390_get_reg(&spi->dev, DS1390_REG_SECONDS, &tmp);  in ds1390_probe()
199 		dev_err(&spi->dev, "unable to read device\n");  in ds1390_probe()
203 	if (spi->dev.of_node)  in ds1390_probe()
206 	chip->rtc = devm_rtc_device_register(&spi->dev, "ds1390",  in ds1390_probe()
208 	if (IS_ERR(chip->rtc)) {  in ds1390_probe()
209 		dev_err(&spi->dev, "unable to register device\n");  in ds1390_probe()
210 		res = PTR_ERR(chip->rtc);  in ds1390_probe()
230 		.name	= "rtc-ds1390",
242 MODULE_ALIAS("spi:rtc-ds1390");