diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/rtc-tps6594.c | 454 |
3 files changed, 467 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 4e3c2fde2d6a..68a530ef1066 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -578,6 +578,18 @@ config RTC_DRV_TPS6586X along with alarm. This driver supports the RTC driver for the TPS6586X RTC module. +config RTC_DRV_TPS6594 + tristate "TI TPS6594 RTC driver" + depends on MFD_TPS6594 + default MFD_TPS6594 + help + TI Power Management IC TPS6594 supports RTC functionality + along with alarm. This driver supports the RTC driver for + the TPS6594 RTC module. + + This driver can also be built as a module. If so, the module + will be called rtc-tps6594. + config RTC_DRV_TPS65910 tristate "TI TPS65910 RTC driver" depends on MFD_TPS65910 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 6817ea4e4468..31c4606fd9bf 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -177,6 +177,7 @@ obj-$(CONFIG_RTC_DRV_TEGRA) += rtc-tegra.o obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o obj-$(CONFIG_RTC_DRV_TI_K3) += rtc-ti-k3.o obj-$(CONFIG_RTC_DRV_TPS6586X) += rtc-tps6586x.o +obj-$(CONFIG_RTC_DRV_TPS6594) += rtc-tps6594.o obj-$(CONFIG_RTC_DRV_TPS65910) += rtc-tps65910.o obj-$(CONFIG_RTC_DRV_TWL4030) += rtc-twl.o obj-$(CONFIG_RTC_DRV_VT8500) += rtc-vt8500.o diff --git a/drivers/rtc/rtc-tps6594.c b/drivers/rtc/rtc-tps6594.c new file mode 100644 index 000000000000..838ae8562a35 --- /dev/null +++ b/drivers/rtc/rtc-tps6594.c @@ -0,0 +1,454 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC driver for tps6594 PMIC + * + * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/ + */ + +#include <linux/bcd.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/math64.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/mod_devicetable.h> +#include <linux/property.h> +#include <linux/rtc.h> +#include <linux/types.h> +#include <linux/units.h> + +#include <linux/mfd/tps6594.h> + +// Total number of RTC registers needed to set time +#define NUM_TIME_REGS (TPS6594_REG_RTC_WEEKS - TPS6594_REG_RTC_SECONDS + 1) + +// Total number of RTC alarm registers +#define NUM_TIME_ALARM_REGS (NUM_TIME_REGS - 1) + +/* + * Min and max values supported by 'offset' interface (swapped sign). + * After conversion, the values do not exceed the range [-32767, 33767] + * which COMP_REG must conform to. + */ +#define MIN_OFFSET (-277774) +#define MAX_OFFSET (277774) + +// Number of ticks per hour +#define TICKS_PER_HOUR (32768 * 3600) + +// Multiplier for ppb conversions +#define PPB_MULT NANO + +static int tps6594_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct tps6594 *tps = dev_get_drvdata(dev->parent); + u8 val; + + val = enabled ? TPS6594_BIT_IT_ALARM : 0; + + return regmap_update_bits(tps->regmap, TPS6594_REG_RTC_INTERRUPTS, + TPS6594_BIT_IT_ALARM, val); +} + +/* Pulse GET_TIME field of RTC_CTRL_1 to store a timestamp in shadow registers. */ +static int tps6594_rtc_shadow_timestamp(struct device *dev, struct tps6594 *tps) +{ + int ret; + + /* + * Set GET_TIME to 0. Next time we set GET_TIME to 1 we will be sure to store + * an up-to-date timestamp. + */ + ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_GET_TIME); + if (ret < 0) + return ret; + + /* + * Copy content of RTC registers to shadow registers or latches to read + * a coherent timestamp. + */ + return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_GET_TIME); +} + +static int tps6594_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char rtc_data[NUM_TIME_REGS]; + struct tps6594 *tps = dev_get_drvdata(dev->parent); + int ret; + + // Check if RTC is running. + ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, + TPS6594_BIT_RUN); + if (ret < 0) + return ret; + if (ret == 0) + return -EINVAL; + + ret = tps6594_rtc_shadow_timestamp(dev, tps); + if (ret < 0) + return ret; + + // Read shadowed RTC registers. + ret = regmap_bulk_read(tps->regmap, TPS6594_REG_RTC_SECONDS, rtc_data, + NUM_TIME_REGS); + if (ret < 0) + return ret; + + tm->tm_sec = bcd2bin(rtc_data[0]); + tm->tm_min = bcd2bin(rtc_data[1]); + tm->tm_hour = bcd2bin(rtc_data[2]); + tm->tm_mday = bcd2bin(rtc_data[3]); + tm->tm_mon = bcd2bin(rtc_data[4]) - 1; + tm->tm_year = bcd2bin(rtc_data[5]) + 100; + tm->tm_wday = bcd2bin(rtc_data[6]); + + return 0; +} + +static int tps6594_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char rtc_data[NUM_TIME_REGS]; + struct tps6594 *tps = dev_get_drvdata(dev->parent); + int ret; + + rtc_data[0] = bin2bcd(tm->tm_sec); + rtc_data[1] = bin2bcd(tm->tm_min); + rtc_data[2] = bin2bcd(tm->tm_hour); + rtc_data[3] = bin2bcd(tm->tm_mday); + rtc_data[4] = bin2bcd(tm->tm_mon + 1); + rtc_data[5] = bin2bcd(tm->tm_year - 100); + rtc_data[6] = bin2bcd(tm->tm_wday); + + // Stop RTC while updating the RTC time registers. + ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_STOP_RTC); + if (ret < 0) + return ret; + + // Update all the time registers in one shot. + ret = regmap_bulk_write(tps->regmap, TPS6594_REG_RTC_SECONDS, rtc_data, + NUM_TIME_REGS); + if (ret < 0) + return ret; + + // Start back RTC. + return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_STOP_RTC); +} + +static int tps6594_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + unsigned char alarm_data[NUM_TIME_ALARM_REGS]; + u32 int_val; + struct tps6594 *tps = dev_get_drvdata(dev->parent); + int ret; + + ret = regmap_bulk_read(tps->regmap, TPS6594_REG_ALARM_SECONDS, + alarm_data, NUM_TIME_ALARM_REGS); + if (ret < 0) + return ret; + + alm->time.tm_sec = bcd2bin(alarm_data[0]); + alm->time.tm_min = bcd2bin(alarm_data[1]); + alm->time.tm_hour = bcd2bin(alarm_data[2]); + alm->time.tm_mday = bcd2bin(alarm_data[3]); + alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; + alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; + + ret = regmap_read(tps->regmap, TPS6594_REG_RTC_INTERRUPTS, &int_val); + if (ret < 0) + return ret; + + alm->enabled = int_val & TPS6594_BIT_IT_ALARM; + + return 0; +} + +static int tps6594_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + unsigned char alarm_data[NUM_TIME_ALARM_REGS]; + struct tps6594 *tps = dev_get_drvdata(dev->parent); + int ret; + + // Disable alarm irq before changing the alarm timestamp. + ret = tps6594_rtc_alarm_irq_enable(dev, 0); + if (ret) + return ret; + + alarm_data[0] = bin2bcd(alm->time.tm_sec); + alarm_data[1] = bin2bcd(alm->time.tm_min); + alarm_data[2] = bin2bcd(alm->time.tm_hour); + alarm_data[3] = bin2bcd(alm->time.tm_mday); + alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); + alarm_data[5] = bin2bcd(alm->time.tm_year - 100); + + // Update all the alarm registers in one shot. + ret = regmap_bulk_write(tps->regmap, TPS6594_REG_ALARM_SECONDS, + alarm_data, NUM_TIME_ALARM_REGS); + if (ret < 0) + return ret; + + if (alm->enabled) + ret = tps6594_rtc_alarm_irq_enable(dev, 1); + + return ret; +} + +static int tps6594_rtc_set_calibration(struct device *dev, int calibration) +{ + struct tps6594 *tps = dev_get_drvdata(dev->parent); + __le16 value; + int ret; + + /* + * TPS6594 uses two's complement 16 bit value for compensation of RTC + * crystal inaccuracies. One time every hour when seconds counter + * increments from 0 to 1 compensation value will be added to internal + * RTC counter value. + * + * Valid range for compensation value: [-32767 .. 32767]. + */ + if (calibration < S16_MIN + 1 || calibration > S16_MAX) + return -ERANGE; + + value = cpu_to_le16(calibration); + + // Update all the compensation registers in one shot. + ret = regmap_bulk_write(tps->regmap, TPS6594_REG_RTC_COMP_LSB, &value, + sizeof(value)); + if (ret < 0) + return ret; + + // Enable automatic compensation. + return regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_AUTO_COMP); +} + +static int tps6594_rtc_get_calibration(struct device *dev, int *calibration) +{ + struct tps6594 *tps = dev_get_drvdata(dev->parent); + unsigned int ctrl; + __le16 value; + int ret; + + ret = regmap_read(tps->regmap, TPS6594_REG_RTC_CTRL_1, &ctrl); + if (ret < 0) + return ret; + + // If automatic compensation is not enabled report back zero. + if (!(ctrl & TPS6594_BIT_AUTO_COMP)) { + *calibration = 0; + return 0; + } + + ret = regmap_bulk_read(tps->regmap, TPS6594_REG_RTC_COMP_LSB, &value, + sizeof(value)); + if (ret < 0) + return ret; + + *calibration = le16_to_cpu(value); + + return 0; +} + +static int tps6594_rtc_read_offset(struct device *dev, long *offset) +{ + int calibration; + s64 tmp; + int ret; + + ret = tps6594_rtc_get_calibration(dev, &calibration); + if (ret < 0) + return ret; + + // Convert from RTC calibration register format to ppb format. + tmp = calibration * PPB_MULT; + + if (tmp < 0) + tmp -= TICKS_PER_HOUR / 2LL; + else + tmp += TICKS_PER_HOUR / 2LL; + tmp = div_s64(tmp, TICKS_PER_HOUR); + + /* + * SAFETY: + * Computatiion is the reverse operation of the one done in + * `tps6594_rtc_set_offset`. The safety remarks applie here too. + */ + + /* + * Offset value operates in negative way, so swap sign. + * See 8.3.10.5, (32768 - COMP_REG). + */ + *offset = (long)-tmp; + + return 0; +} + +static int tps6594_rtc_set_offset(struct device *dev, long offset) +{ + int calibration; + s64 tmp; + + // Make sure offset value is within supported range. + if (offset < MIN_OFFSET || offset > MAX_OFFSET) + return -ERANGE; + + // Convert from ppb format to RTC calibration register format. + + tmp = offset * TICKS_PER_HOUR; + if (tmp < 0) + tmp -= PPB_MULT / 2LL; + else + tmp += PPB_MULT / 2LL; + tmp = div_s64(tmp, PPB_MULT); + + /* + * SAFETY: + * - tmp = offset * TICK_PER_HOUR : + * `offset` can't be more than 277774, so `tmp` can't exceed 277774000000000 + * which is lower than the maximum value in an `s64` (2^63-1). No overflow here. + * + * - tmp += TICK_PER_HOUR / 2LL : + * tmp will have a maximum value of 277774117964800 which is still inferior to 2^63-1. + */ + + // Offset value operates in negative way, so swap sign. + calibration = (int)-tmp; + + return tps6594_rtc_set_calibration(dev, calibration); +} + +static irqreturn_t tps6594_rtc_interrupt(int irq, void *rtc) +{ + struct device *dev = rtc; + struct tps6594 *tps = dev_get_drvdata(dev->parent); + struct rtc_device *rtc_dev = dev_get_drvdata(dev); + int ret; + u32 rtc_reg; + + ret = regmap_read(tps->regmap, TPS6594_REG_RTC_STATUS, &rtc_reg); + if (ret) + return IRQ_NONE; + + rtc_update_irq(rtc_dev, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops tps6594_rtc_ops = { + .read_time = tps6594_rtc_read_time, + .set_time = tps6594_rtc_set_time, + .read_alarm = tps6594_rtc_read_alarm, + .set_alarm = tps6594_rtc_set_alarm, + .alarm_irq_enable = tps6594_rtc_alarm_irq_enable, + .read_offset = tps6594_rtc_read_offset, + .set_offset = tps6594_rtc_set_offset, +}; + +static int tps6594_rtc_probe(struct platform_device *pdev) +{ + struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent); + struct device *dev = &pdev->dev; + struct rtc_device *rtc; + int irq; + int ret; + + rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + // Enable crystal oscillator. + ret = regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_2, + TPS6594_BIT_XTAL_EN); + if (ret < 0) + return ret; + + ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, + TPS6594_BIT_RUN); + if (ret < 0) + return ret; + // RTC not running. + if (ret == 0) { + ret = regmap_set_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_STOP_RTC); + if (ret < 0) + return ret; + + /* + * On some boards, a 40 ms delay is needed before BIT_RUN is set. + * 80 ms should provide sufficient margin. + */ + mdelay(80); + + /* + * RTC should be running now. Check if this is the case. + * If not it might be a missing oscillator. + */ + ret = regmap_test_bits(tps->regmap, TPS6594_REG_RTC_STATUS, + TPS6594_BIT_RUN); + if (ret < 0) + return ret; + if (ret == 0) + return -ENODEV; + + // Stop RTC until first call to `tps6594_rtc_set_time`. + ret = regmap_clear_bits(tps->regmap, TPS6594_REG_RTC_CTRL_1, + TPS6594_BIT_STOP_RTC); + if (ret < 0) + return ret; + } + + platform_set_drvdata(pdev, rtc); + + irq = platform_get_irq_byname(pdev, TPS6594_IRQ_NAME_ALARM); + if (irq < 0) + return dev_err_probe(dev, irq, "Failed to get irq\n"); + + ret = devm_request_threaded_irq(dev, irq, NULL, tps6594_rtc_interrupt, + IRQF_ONESHOT, TPS6594_IRQ_NAME_ALARM, + dev); + if (ret < 0) + return dev_err_probe(dev, ret, + "Failed to request_threaded_irq\n"); + + ret = device_init_wakeup(dev, true); + if (ret < 0) + return dev_err_probe(dev, ret, + "Failed to init rtc as wakeup source\n"); + + rtc->ops = &tps6594_rtc_ops; + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + + return devm_rtc_register_device(rtc); +} + +static const struct platform_device_id tps6594_rtc_id_table[] = { + { "tps6594-rtc", }, + {} +}; +MODULE_DEVICE_TABLE(platform, tps6594_rtc_id_table); + +static struct platform_driver tps6594_rtc_driver = { + .probe = tps6594_rtc_probe, + .driver = { + .name = "tps6594-rtc", + }, + .id_table = tps6594_rtc_id_table, +}; + +module_platform_driver(tps6594_rtc_driver); +MODULE_AUTHOR("Esteban Blanc <eblanc@baylibre.com>"); +MODULE_DESCRIPTION("TPS6594 RTC driver"); +MODULE_LICENSE("GPL"); |