Wed, Jun 28, 2023 at 03:30:20PM +0200, Esteban Blanc kirjoitti: > TPS6594 PMIC is a MFD. This patch adds support for > the RTC found inside TPS6594 family of PMIC. > > Alarm is also supported. LGTM from generic style and code comments perspective, Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Signed-off-by: Esteban Blanc <eblanc@xxxxxxxxxxxx> > --- > drivers/rtc/Kconfig | 12 + > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-tps6594.c | 452 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 465 insertions(+) > create mode 100644 drivers/rtc/rtc-tps6594.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 753872408615..39b5c93c6282 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 ea445d1ebb17..3d3f8c9d0697 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -175,6 +175,7 @@ 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..7328ea7da849 > --- /dev/null > +++ b/drivers/rtc/rtc-tps6594.c > @@ -0,0 +1,452 @@ > +// 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/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: > + * Compution 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; > + unsigned long events = 0; > + 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; > + > + if (rtc_reg & TPS6594_BIT_ALARM) > + events = RTC_IRQF | RTC_AF; > + > + // Notify RTC core on event. > + rtc_update_irq(rtc_dev, 1, events); > + > + 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 struct platform_driver tps6594_rtc_driver = { > + .probe = tps6594_rtc_probe, > + .driver = { > + .name = "tps6594-rtc", > + }, > +}; > + > +module_platform_driver(tps6594_rtc_driver); > +MODULE_ALIAS("platform:tps6594-rtc"); > +MODULE_AUTHOR("Esteban Blanc <eblanc@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("TPS6594 RTC driver"); > +MODULE_LICENSE("GPL"); > -- > 2.41.0 > -- With Best Regards, Andy Shevchenko
