1617b26a0SRaghavendra Ganiga /* rtc-ds1347.c 2617b26a0SRaghavendra Ganiga * 3617b26a0SRaghavendra Ganiga * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible 4617b26a0SRaghavendra Ganiga * Real Time Clock 5617b26a0SRaghavendra Ganiga * 6617b26a0SRaghavendra Ganiga * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> 7617b26a0SRaghavendra Ganiga * 8617b26a0SRaghavendra Ganiga * This program is free software; you can redistribute it and/or modify 9617b26a0SRaghavendra Ganiga * it under the terms of the GNU General Public License version 2 as 10617b26a0SRaghavendra Ganiga * published by the Free Software Foundation. 11617b26a0SRaghavendra Ganiga * 12617b26a0SRaghavendra Ganiga */ 13617b26a0SRaghavendra Ganiga 14617b26a0SRaghavendra Ganiga #include <linux/init.h> 15617b26a0SRaghavendra Ganiga #include <linux/module.h> 16617b26a0SRaghavendra Ganiga #include <linux/device.h> 17617b26a0SRaghavendra Ganiga #include <linux/platform_device.h> 18617b26a0SRaghavendra Ganiga #include <linux/rtc.h> 19617b26a0SRaghavendra Ganiga #include <linux/spi/spi.h> 20617b26a0SRaghavendra Ganiga #include <linux/bcd.h> 21ee85bb5bSRaghavendra Ganiga #include <linux/regmap.h> 22617b26a0SRaghavendra Ganiga 23617b26a0SRaghavendra Ganiga /* Registers in ds1347 rtc */ 24617b26a0SRaghavendra Ganiga 25617b26a0SRaghavendra Ganiga #define DS1347_SECONDS_REG 0x01 26617b26a0SRaghavendra Ganiga #define DS1347_MINUTES_REG 0x03 27617b26a0SRaghavendra Ganiga #define DS1347_HOURS_REG 0x05 28617b26a0SRaghavendra Ganiga #define DS1347_DATE_REG 0x07 29617b26a0SRaghavendra Ganiga #define DS1347_MONTH_REG 0x09 30617b26a0SRaghavendra Ganiga #define DS1347_DAY_REG 0x0B 31617b26a0SRaghavendra Ganiga #define DS1347_YEAR_REG 0x0D 32617b26a0SRaghavendra Ganiga #define DS1347_CONTROL_REG 0x0F 33617b26a0SRaghavendra Ganiga #define DS1347_STATUS_REG 0x17 34617b26a0SRaghavendra Ganiga #define DS1347_CLOCK_BURST 0x3F 35617b26a0SRaghavendra Ganiga 36ee85bb5bSRaghavendra Ganiga static const struct regmap_range ds1347_ranges[] = { 37617b26a0SRaghavendra Ganiga { 38ee85bb5bSRaghavendra Ganiga .range_min = DS1347_SECONDS_REG, 39ee85bb5bSRaghavendra Ganiga .range_max = DS1347_STATUS_REG, 40ee85bb5bSRaghavendra Ganiga }, 41ee85bb5bSRaghavendra Ganiga }; 42617b26a0SRaghavendra Ganiga 43ee85bb5bSRaghavendra Ganiga static const struct regmap_access_table ds1347_access_table = { 44ee85bb5bSRaghavendra Ganiga .yes_ranges = ds1347_ranges, 45ee85bb5bSRaghavendra Ganiga .n_yes_ranges = ARRAY_SIZE(ds1347_ranges), 46ee85bb5bSRaghavendra Ganiga }; 47617b26a0SRaghavendra Ganiga 48617b26a0SRaghavendra Ganiga static int ds1347_read_time(struct device *dev, struct rtc_time *dt) 49617b26a0SRaghavendra Ganiga { 50617b26a0SRaghavendra Ganiga struct spi_device *spi = to_spi_device(dev); 51ee85bb5bSRaghavendra Ganiga struct regmap *map; 52617b26a0SRaghavendra Ganiga int err; 53617b26a0SRaghavendra Ganiga unsigned char buf[8]; 54617b26a0SRaghavendra Ganiga 55ee85bb5bSRaghavendra Ganiga map = spi_get_drvdata(spi); 56617b26a0SRaghavendra Ganiga 57ee85bb5bSRaghavendra Ganiga err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8); 58617b26a0SRaghavendra Ganiga if (err) 59617b26a0SRaghavendra Ganiga return err; 60617b26a0SRaghavendra Ganiga 61617b26a0SRaghavendra Ganiga dt->tm_sec = bcd2bin(buf[0]); 62617b26a0SRaghavendra Ganiga dt->tm_min = bcd2bin(buf[1]); 63617b26a0SRaghavendra Ganiga dt->tm_hour = bcd2bin(buf[2] & 0x3F); 64617b26a0SRaghavendra Ganiga dt->tm_mday = bcd2bin(buf[3]); 65617b26a0SRaghavendra Ganiga dt->tm_mon = bcd2bin(buf[4]) - 1; 66617b26a0SRaghavendra Ganiga dt->tm_wday = bcd2bin(buf[5]) - 1; 67617b26a0SRaghavendra Ganiga dt->tm_year = bcd2bin(buf[6]) + 100; 68617b26a0SRaghavendra Ganiga 6922652ba7SAlexandre Belloni return 0; 70617b26a0SRaghavendra Ganiga } 71617b26a0SRaghavendra Ganiga 72617b26a0SRaghavendra Ganiga static int ds1347_set_time(struct device *dev, struct rtc_time *dt) 73617b26a0SRaghavendra Ganiga { 74617b26a0SRaghavendra Ganiga struct spi_device *spi = to_spi_device(dev); 75ee85bb5bSRaghavendra Ganiga struct regmap *map; 76ee85bb5bSRaghavendra Ganiga unsigned char buf[8]; 77617b26a0SRaghavendra Ganiga 78ee85bb5bSRaghavendra Ganiga map = spi_get_drvdata(spi); 79ee85bb5bSRaghavendra Ganiga 80ee85bb5bSRaghavendra Ganiga buf[0] = bin2bcd(dt->tm_sec); 81ee85bb5bSRaghavendra Ganiga buf[1] = bin2bcd(dt->tm_min); 82ee85bb5bSRaghavendra Ganiga buf[2] = (bin2bcd(dt->tm_hour) & 0x3F); 83ee85bb5bSRaghavendra Ganiga buf[3] = bin2bcd(dt->tm_mday); 84ee85bb5bSRaghavendra Ganiga buf[4] = bin2bcd(dt->tm_mon + 1); 85ee85bb5bSRaghavendra Ganiga buf[5] = bin2bcd(dt->tm_wday + 1); 86617b26a0SRaghavendra Ganiga 87617b26a0SRaghavendra Ganiga /* year in linux is from 1900 i.e in range of 100 88617b26a0SRaghavendra Ganiga in rtc it is from 00 to 99 */ 89617b26a0SRaghavendra Ganiga dt->tm_year = dt->tm_year % 100; 90617b26a0SRaghavendra Ganiga 91ee85bb5bSRaghavendra Ganiga buf[6] = bin2bcd(dt->tm_year); 92ee85bb5bSRaghavendra Ganiga buf[7] = bin2bcd(0x00); 93617b26a0SRaghavendra Ganiga 94617b26a0SRaghavendra Ganiga /* write the rtc settings */ 95ee85bb5bSRaghavendra Ganiga return regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); 96617b26a0SRaghavendra Ganiga } 97617b26a0SRaghavendra Ganiga 98617b26a0SRaghavendra Ganiga static const struct rtc_class_ops ds1347_rtc_ops = { 99617b26a0SRaghavendra Ganiga .read_time = ds1347_read_time, 100617b26a0SRaghavendra Ganiga .set_time = ds1347_set_time, 101617b26a0SRaghavendra Ganiga }; 102617b26a0SRaghavendra Ganiga 103617b26a0SRaghavendra Ganiga static int ds1347_probe(struct spi_device *spi) 104617b26a0SRaghavendra Ganiga { 105617b26a0SRaghavendra Ganiga struct rtc_device *rtc; 106ee85bb5bSRaghavendra Ganiga struct regmap_config config; 107ee85bb5bSRaghavendra Ganiga struct regmap *map; 108ee85bb5bSRaghavendra Ganiga unsigned int data; 109617b26a0SRaghavendra Ganiga int res; 110617b26a0SRaghavendra Ganiga 111ee85bb5bSRaghavendra Ganiga memset(&config, 0, sizeof(config)); 112ee85bb5bSRaghavendra Ganiga config.reg_bits = 8; 113ee85bb5bSRaghavendra Ganiga config.val_bits = 8; 114ee85bb5bSRaghavendra Ganiga config.read_flag_mask = 0x80; 115ee85bb5bSRaghavendra Ganiga config.max_register = 0x3F; 116ee85bb5bSRaghavendra Ganiga config.wr_table = &ds1347_access_table; 117ee85bb5bSRaghavendra Ganiga 118617b26a0SRaghavendra Ganiga /* spi setup with ds1347 in mode 3 and bits per word as 8 */ 119617b26a0SRaghavendra Ganiga spi->mode = SPI_MODE_3; 120617b26a0SRaghavendra Ganiga spi->bits_per_word = 8; 121617b26a0SRaghavendra Ganiga spi_setup(spi); 122617b26a0SRaghavendra Ganiga 123ee85bb5bSRaghavendra Ganiga map = devm_regmap_init_spi(spi, &config); 124ee85bb5bSRaghavendra Ganiga 125ee85bb5bSRaghavendra Ganiga if (IS_ERR(map)) { 126ee85bb5bSRaghavendra Ganiga dev_err(&spi->dev, "ds1347 regmap init spi failed\n"); 127ee85bb5bSRaghavendra Ganiga return PTR_ERR(map); 128ee85bb5bSRaghavendra Ganiga } 129ee85bb5bSRaghavendra Ganiga 130ee85bb5bSRaghavendra Ganiga spi_set_drvdata(spi, map); 131ee85bb5bSRaghavendra Ganiga 132617b26a0SRaghavendra Ganiga /* RTC Settings */ 133ee85bb5bSRaghavendra Ganiga res = regmap_read(map, DS1347_SECONDS_REG, &data); 134617b26a0SRaghavendra Ganiga if (res) 135617b26a0SRaghavendra Ganiga return res; 136617b26a0SRaghavendra Ganiga 137617b26a0SRaghavendra Ganiga /* Disable the write protect of rtc */ 138ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_CONTROL_REG, &data); 139617b26a0SRaghavendra Ganiga data = data & ~(1<<7); 140ee85bb5bSRaghavendra Ganiga regmap_write(map, DS1347_CONTROL_REG, data); 141617b26a0SRaghavendra Ganiga 142617b26a0SRaghavendra Ganiga /* Enable the oscillator , disable the oscillator stop flag, 143617b26a0SRaghavendra Ganiga and glitch filter to reduce current consumption */ 144ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_STATUS_REG, &data); 145617b26a0SRaghavendra Ganiga data = data & 0x1B; 146ee85bb5bSRaghavendra Ganiga regmap_write(map, DS1347_STATUS_REG, data); 147617b26a0SRaghavendra Ganiga 148617b26a0SRaghavendra Ganiga /* display the settings */ 149ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_CONTROL_REG, &data); 150617b26a0SRaghavendra Ganiga dev_info(&spi->dev, "DS1347 RTC CTRL Reg = 0x%02x\n", data); 151617b26a0SRaghavendra Ganiga 152ee85bb5bSRaghavendra Ganiga regmap_read(map, DS1347_STATUS_REG, &data); 153617b26a0SRaghavendra Ganiga dev_info(&spi->dev, "DS1347 RTC Status Reg = 0x%02x\n", data); 154617b26a0SRaghavendra Ganiga 155617b26a0SRaghavendra Ganiga rtc = devm_rtc_device_register(&spi->dev, "ds1347", 156617b26a0SRaghavendra Ganiga &ds1347_rtc_ops, THIS_MODULE); 157617b26a0SRaghavendra Ganiga 158617b26a0SRaghavendra Ganiga if (IS_ERR(rtc)) 159617b26a0SRaghavendra Ganiga return PTR_ERR(rtc); 160617b26a0SRaghavendra Ganiga 161617b26a0SRaghavendra Ganiga return 0; 162617b26a0SRaghavendra Ganiga } 163617b26a0SRaghavendra Ganiga 164617b26a0SRaghavendra Ganiga static struct spi_driver ds1347_driver = { 165617b26a0SRaghavendra Ganiga .driver = { 166617b26a0SRaghavendra Ganiga .name = "ds1347", 167617b26a0SRaghavendra Ganiga }, 168617b26a0SRaghavendra Ganiga .probe = ds1347_probe, 169617b26a0SRaghavendra Ganiga }; 170617b26a0SRaghavendra Ganiga 171617b26a0SRaghavendra Ganiga module_spi_driver(ds1347_driver); 172617b26a0SRaghavendra Ganiga 173617b26a0SRaghavendra Ganiga MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); 174617b26a0SRaghavendra Ganiga MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); 175617b26a0SRaghavendra Ganiga MODULE_LICENSE("GPL v2"); 176