1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2617b26a0SRaghavendra Ganiga /* rtc-ds1347.c 3617b26a0SRaghavendra Ganiga * 4617b26a0SRaghavendra Ganiga * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible 5617b26a0SRaghavendra Ganiga * Real Time Clock 6617b26a0SRaghavendra Ganiga * 7617b26a0SRaghavendra Ganiga * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> 8617b26a0SRaghavendra Ganiga */ 9617b26a0SRaghavendra Ganiga 10617b26a0SRaghavendra Ganiga #include <linux/init.h> 11617b26a0SRaghavendra Ganiga #include <linux/module.h> 12617b26a0SRaghavendra Ganiga #include <linux/device.h> 13617b26a0SRaghavendra Ganiga #include <linux/platform_device.h> 14617b26a0SRaghavendra Ganiga #include <linux/rtc.h> 15617b26a0SRaghavendra Ganiga #include <linux/spi/spi.h> 16617b26a0SRaghavendra Ganiga #include <linux/bcd.h> 17ee85bb5bSRaghavendra Ganiga #include <linux/regmap.h> 18617b26a0SRaghavendra Ganiga 19617b26a0SRaghavendra Ganiga /* Registers in ds1347 rtc */ 20617b26a0SRaghavendra Ganiga 21617b26a0SRaghavendra Ganiga #define DS1347_SECONDS_REG 0x01 22617b26a0SRaghavendra Ganiga #define DS1347_MINUTES_REG 0x03 23617b26a0SRaghavendra Ganiga #define DS1347_HOURS_REG 0x05 24617b26a0SRaghavendra Ganiga #define DS1347_DATE_REG 0x07 25617b26a0SRaghavendra Ganiga #define DS1347_MONTH_REG 0x09 26617b26a0SRaghavendra Ganiga #define DS1347_DAY_REG 0x0B 27617b26a0SRaghavendra Ganiga #define DS1347_YEAR_REG 0x0D 28617b26a0SRaghavendra Ganiga #define DS1347_CONTROL_REG 0x0F 29617b26a0SRaghavendra Ganiga #define DS1347_STATUS_REG 0x17 30617b26a0SRaghavendra Ganiga #define DS1347_CLOCK_BURST 0x3F 31617b26a0SRaghavendra Ganiga 32ee85bb5bSRaghavendra Ganiga static const struct regmap_range ds1347_ranges[] = { 33617b26a0SRaghavendra Ganiga { 34ee85bb5bSRaghavendra Ganiga .range_min = DS1347_SECONDS_REG, 35ee85bb5bSRaghavendra Ganiga .range_max = DS1347_STATUS_REG, 36ee85bb5bSRaghavendra Ganiga }, 37ee85bb5bSRaghavendra Ganiga }; 38617b26a0SRaghavendra Ganiga 39ee85bb5bSRaghavendra Ganiga static const struct regmap_access_table ds1347_access_table = { 40ee85bb5bSRaghavendra Ganiga .yes_ranges = ds1347_ranges, 41ee85bb5bSRaghavendra Ganiga .n_yes_ranges = ARRAY_SIZE(ds1347_ranges), 42ee85bb5bSRaghavendra Ganiga }; 43617b26a0SRaghavendra Ganiga 44617b26a0SRaghavendra Ganiga static int ds1347_read_time(struct device *dev, struct rtc_time *dt) 45617b26a0SRaghavendra Ganiga { 46617b26a0SRaghavendra Ganiga struct spi_device *spi = to_spi_device(dev); 47ee85bb5bSRaghavendra Ganiga struct regmap *map; 48617b26a0SRaghavendra Ganiga int err; 49617b26a0SRaghavendra Ganiga unsigned char buf[8]; 50617b26a0SRaghavendra Ganiga 51ee85bb5bSRaghavendra Ganiga map = spi_get_drvdata(spi); 52617b26a0SRaghavendra Ganiga 53ee85bb5bSRaghavendra Ganiga err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8); 54617b26a0SRaghavendra Ganiga if (err) 55617b26a0SRaghavendra Ganiga return err; 56617b26a0SRaghavendra Ganiga 57617b26a0SRaghavendra Ganiga dt->tm_sec = bcd2bin(buf[0]); 58617b26a0SRaghavendra Ganiga dt->tm_min = bcd2bin(buf[1]); 59617b26a0SRaghavendra Ganiga dt->tm_hour = bcd2bin(buf[2] & 0x3F); 60617b26a0SRaghavendra Ganiga dt->tm_mday = bcd2bin(buf[3]); 61617b26a0SRaghavendra Ganiga dt->tm_mon = bcd2bin(buf[4]) - 1; 62617b26a0SRaghavendra Ganiga dt->tm_wday = bcd2bin(buf[5]) - 1; 63617b26a0SRaghavendra Ganiga dt->tm_year = bcd2bin(buf[6]) + 100; 64617b26a0SRaghavendra Ganiga 6522652ba7SAlexandre Belloni return 0; 66617b26a0SRaghavendra Ganiga } 67617b26a0SRaghavendra Ganiga 68617b26a0SRaghavendra Ganiga static int ds1347_set_time(struct device *dev, struct rtc_time *dt) 69617b26a0SRaghavendra Ganiga { 70617b26a0SRaghavendra Ganiga struct spi_device *spi = to_spi_device(dev); 71ee85bb5bSRaghavendra Ganiga struct regmap *map; 72ee85bb5bSRaghavendra Ganiga unsigned char buf[8]; 73617b26a0SRaghavendra Ganiga 74ee85bb5bSRaghavendra Ganiga map = spi_get_drvdata(spi); 75ee85bb5bSRaghavendra Ganiga 76ee85bb5bSRaghavendra Ganiga buf[0] = bin2bcd(dt->tm_sec); 77ee85bb5bSRaghavendra Ganiga buf[1] = bin2bcd(dt->tm_min); 78ee85bb5bSRaghavendra Ganiga buf[2] = (bin2bcd(dt->tm_hour) & 0x3F); 79ee85bb5bSRaghavendra Ganiga buf[3] = bin2bcd(dt->tm_mday); 80ee85bb5bSRaghavendra Ganiga buf[4] = bin2bcd(dt->tm_mon + 1); 81ee85bb5bSRaghavendra Ganiga buf[5] = bin2bcd(dt->tm_wday + 1); 82617b26a0SRaghavendra Ganiga 83617b26a0SRaghavendra Ganiga /* year in linux is from 1900 i.e in range of 100 84617b26a0SRaghavendra Ganiga in rtc it is from 00 to 99 */ 85617b26a0SRaghavendra Ganiga dt->tm_year = dt->tm_year % 100; 86617b26a0SRaghavendra Ganiga 87ee85bb5bSRaghavendra Ganiga buf[6] = bin2bcd(dt->tm_year); 88ee85bb5bSRaghavendra Ganiga buf[7] = bin2bcd(0x00); 89617b26a0SRaghavendra Ganiga 90617b26a0SRaghavendra Ganiga /* write the rtc settings */ 91ee85bb5bSRaghavendra Ganiga return regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); 92617b26a0SRaghavendra Ganiga } 93617b26a0SRaghavendra Ganiga 94617b26a0SRaghavendra Ganiga static const struct rtc_class_ops ds1347_rtc_ops = { 95617b26a0SRaghavendra Ganiga .read_time = ds1347_read_time, 96617b26a0SRaghavendra Ganiga .set_time = ds1347_set_time, 97617b26a0SRaghavendra Ganiga }; 98617b26a0SRaghavendra Ganiga 99617b26a0SRaghavendra Ganiga static int ds1347_probe(struct spi_device *spi) 100617b26a0SRaghavendra Ganiga { 101617b26a0SRaghavendra Ganiga struct rtc_device *rtc; 102ee85bb5bSRaghavendra Ganiga struct regmap_config config; 103ee85bb5bSRaghavendra Ganiga struct regmap *map; 104ee85bb5bSRaghavendra Ganiga unsigned int data; 105617b26a0SRaghavendra Ganiga int res; 106617b26a0SRaghavendra Ganiga 107ee85bb5bSRaghavendra Ganiga memset(&config, 0, sizeof(config)); 108ee85bb5bSRaghavendra Ganiga config.reg_bits = 8; 109ee85bb5bSRaghavendra Ganiga config.val_bits = 8; 110ee85bb5bSRaghavendra Ganiga config.read_flag_mask = 0x80; 111ee85bb5bSRaghavendra Ganiga config.max_register = 0x3F; 112ee85bb5bSRaghavendra Ganiga config.wr_table = &ds1347_access_table; 113ee85bb5bSRaghavendra Ganiga 114617b26a0SRaghavendra Ganiga /* spi setup with ds1347 in mode 3 and bits per word as 8 */ 115617b26a0SRaghavendra Ganiga spi->mode = SPI_MODE_3; 116617b26a0SRaghavendra Ganiga spi->bits_per_word = 8; 117617b26a0SRaghavendra Ganiga spi_setup(spi); 118617b26a0SRaghavendra Ganiga 119ee85bb5bSRaghavendra Ganiga map = devm_regmap_init_spi(spi, &config); 120ee85bb5bSRaghavendra Ganiga 121ee85bb5bSRaghavendra Ganiga if (IS_ERR(map)) { 122ee85bb5bSRaghavendra Ganiga dev_err(&spi->dev, "ds1347 regmap init spi failed\n"); 123ee85bb5bSRaghavendra Ganiga return PTR_ERR(map); 124ee85bb5bSRaghavendra Ganiga } 125ee85bb5bSRaghavendra Ganiga 126ee85bb5bSRaghavendra Ganiga spi_set_drvdata(spi, map); 127ee85bb5bSRaghavendra Ganiga 128617b26a0SRaghavendra Ganiga /* RTC Settings */ 129ee85bb5bSRaghavendra Ganiga res = regmap_read(map, DS1347_SECONDS_REG, &data); 130617b26a0SRaghavendra Ganiga if (res) 131617b26a0SRaghavendra Ganiga return res; 132617b26a0SRaghavendra Ganiga 133617b26a0SRaghavendra Ganiga /* Disable the write protect of rtc */ 134ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_CONTROL_REG, &data); 135617b26a0SRaghavendra Ganiga data = data & ~(1<<7); 136ee85bb5bSRaghavendra Ganiga regmap_write(map, DS1347_CONTROL_REG, data); 137617b26a0SRaghavendra Ganiga 138617b26a0SRaghavendra Ganiga /* Enable the oscillator , disable the oscillator stop flag, 139617b26a0SRaghavendra Ganiga and glitch filter to reduce current consumption */ 140ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_STATUS_REG, &data); 141617b26a0SRaghavendra Ganiga data = data & 0x1B; 142ee85bb5bSRaghavendra Ganiga regmap_write(map, DS1347_STATUS_REG, data); 143617b26a0SRaghavendra Ganiga 144617b26a0SRaghavendra Ganiga /* display the settings */ 145ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_CONTROL_REG, &data); 146617b26a0SRaghavendra Ganiga dev_info(&spi->dev, "DS1347 RTC CTRL Reg = 0x%02x\n", data); 147617b26a0SRaghavendra Ganiga 148ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_STATUS_REG, &data); 149617b26a0SRaghavendra Ganiga dev_info(&spi->dev, "DS1347 RTC Status Reg = 0x%02x\n", data); 150617b26a0SRaghavendra Ganiga 151617b26a0SRaghavendra Ganiga rtc = devm_rtc_device_register(&spi->dev, "ds1347", 152617b26a0SRaghavendra Ganiga &ds1347_rtc_ops, THIS_MODULE); 153617b26a0SRaghavendra Ganiga 154617b26a0SRaghavendra Ganiga if (IS_ERR(rtc)) 155617b26a0SRaghavendra Ganiga return PTR_ERR(rtc); 156617b26a0SRaghavendra Ganiga 157617b26a0SRaghavendra Ganiga return 0; 158617b26a0SRaghavendra Ganiga } 159617b26a0SRaghavendra Ganiga 160617b26a0SRaghavendra Ganiga static struct spi_driver ds1347_driver = { 161617b26a0SRaghavendra Ganiga .driver = { 162617b26a0SRaghavendra Ganiga .name = "ds1347", 163617b26a0SRaghavendra Ganiga }, 164617b26a0SRaghavendra Ganiga .probe = ds1347_probe, 165617b26a0SRaghavendra Ganiga }; 166617b26a0SRaghavendra Ganiga 167617b26a0SRaghavendra Ganiga module_spi_driver(ds1347_driver); 168617b26a0SRaghavendra Ganiga 169617b26a0SRaghavendra Ganiga MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); 170617b26a0SRaghavendra Ganiga MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); 171617b26a0SRaghavendra Ganiga MODULE_LICENSE("GPL v2"); 172