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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-ds1347.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/rtc/rtc-ds1347.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1347.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c new file mode 100644 index 000000000..a40c1a52d --- /dev/null +++ b/drivers/rtc/rtc-ds1347.c @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* rtc-ds1347.c + * + * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible + * Real Time Clock + * + * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/spi/spi.h> +#include <linux/bcd.h> +#include <linux/regmap.h> + +/* Registers in ds1347 rtc */ + +#define DS1347_SECONDS_REG 0x01 +#define DS1347_MINUTES_REG 0x03 +#define DS1347_HOURS_REG 0x05 +#define DS1347_DATE_REG 0x07 +#define DS1347_MONTH_REG 0x09 +#define DS1347_DAY_REG 0x0B +#define DS1347_YEAR_REG 0x0D +#define DS1347_CONTROL_REG 0x0F +#define DS1347_CENTURY_REG 0x13 +#define DS1347_STATUS_REG 0x17 +#define DS1347_CLOCK_BURST 0x3F + +#define DS1347_WP_BIT BIT(7) + +#define DS1347_NEOSC_BIT BIT(7) +#define DS1347_OSF_BIT BIT(2) + +static const struct regmap_range ds1347_ranges[] = { + { + .range_min = DS1347_SECONDS_REG, + .range_max = DS1347_STATUS_REG, + }, +}; + +static const struct regmap_access_table ds1347_access_table = { + .yes_ranges = ds1347_ranges, + .n_yes_ranges = ARRAY_SIZE(ds1347_ranges), +}; + +static int ds1347_read_time(struct device *dev, struct rtc_time *dt) +{ + struct regmap *map = dev_get_drvdata(dev); + unsigned int status, century, secs; + unsigned char buf[8]; + int err; + + err = regmap_read(map, DS1347_STATUS_REG, &status); + if (err) + return err; + + if (status & DS1347_OSF_BIT) + return -EINVAL; + + do { + err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8); + if (err) + return err; + + err = regmap_read(map, DS1347_CENTURY_REG, ¢ury); + if (err) + return err; + + err = regmap_read(map, DS1347_SECONDS_REG, &secs); + if (err) + return err; + } while (buf[0] != secs); + + dt->tm_sec = bcd2bin(buf[0]); + dt->tm_min = bcd2bin(buf[1] & 0x7f); + dt->tm_hour = bcd2bin(buf[2] & 0x3F); + dt->tm_mday = bcd2bin(buf[3]); + dt->tm_mon = bcd2bin(buf[4]) - 1; + dt->tm_wday = bcd2bin(buf[5]) - 1; + dt->tm_year = (bcd2bin(century) * 100) + bcd2bin(buf[6]) - 1900; + + return 0; +} + +static int ds1347_set_time(struct device *dev, struct rtc_time *dt) +{ + struct regmap *map = dev_get_drvdata(dev); + unsigned int century; + unsigned char buf[8]; + int err; + + err = regmap_update_bits(map, DS1347_STATUS_REG, + DS1347_NEOSC_BIT, DS1347_NEOSC_BIT); + if (err) + return err; + + buf[0] = bin2bcd(dt->tm_sec); + buf[1] = bin2bcd(dt->tm_min); + buf[2] = (bin2bcd(dt->tm_hour) & 0x3F); + buf[3] = bin2bcd(dt->tm_mday); + buf[4] = bin2bcd(dt->tm_mon + 1); + buf[5] = bin2bcd(dt->tm_wday + 1); + buf[6] = bin2bcd(dt->tm_year % 100); + buf[7] = bin2bcd(0x00); + + err = regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8); + if (err) + return err; + + century = (dt->tm_year / 100) + 19; + err = regmap_write(map, DS1347_CENTURY_REG, bin2bcd(century)); + if (err) + return err; + + return regmap_update_bits(map, DS1347_STATUS_REG, + DS1347_NEOSC_BIT | DS1347_OSF_BIT, 0); +} + +static const struct rtc_class_ops ds1347_rtc_ops = { + .read_time = ds1347_read_time, + .set_time = ds1347_set_time, +}; + +static int ds1347_probe(struct spi_device *spi) +{ + struct rtc_device *rtc; + struct regmap_config config; + struct regmap *map; + int err; + + memset(&config, 0, sizeof(config)); + config.reg_bits = 8; + config.val_bits = 8; + config.read_flag_mask = 0x80; + config.max_register = 0x3F; + config.wr_table = &ds1347_access_table; + + /* spi setup with ds1347 in mode 3 and bits per word as 8 */ + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + map = devm_regmap_init_spi(spi, &config); + + if (IS_ERR(map)) { + dev_err(&spi->dev, "ds1347 regmap init spi failed\n"); + return PTR_ERR(map); + } + + spi_set_drvdata(spi, map); + + /* Disable the write protect of rtc */ + err = regmap_update_bits(map, DS1347_CONTROL_REG, DS1347_WP_BIT, 0); + if (err) + return err; + + rtc = devm_rtc_allocate_device(&spi->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &ds1347_rtc_ops; + rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; + rtc->range_max = RTC_TIMESTAMP_END_9999; + + return devm_rtc_register_device(rtc); +} + +static struct spi_driver ds1347_driver = { + .driver = { + .name = "ds1347", + }, + .probe = ds1347_probe, +}; + +module_spi_driver(ds1347_driver); + +MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); +MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); +MODULE_LICENSE("GPL v2"); |
