The BBNSM module includes a real time counter with alarm. Add a RTC driver for this function. Signed-off-by: Jacky Bai <ping.bai@xxxxxxx> Reviewed-by: Peng Fan <peng.fan@xxxxxxx> --- - v2 changes: - sort the header file alphabetically - rename the file to add 'nxp' prefix - refine bbnsm_rtc_irq_handler function, remove the unnecessary event variable - add rtc enable check in .read_time, remove rtc enable in probe function - remove unnecessary dev_err log in probe function --- drivers/rtc/Kconfig | 12 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-nxp-bbnsm.c | 225 ++++++++++++++++++++++++++++++++++++ 3 files changed, 238 insertions(+) create mode 100644 drivers/rtc/rtc-nxp-bbnsm.c diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index ab9a1f814119..0c8534a49c78 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1786,6 +1786,18 @@ config RTC_DRV_SNVS This driver can also be built as a module, if so, the module will be called "rtc-snvs". +config RTC_DRV_BBNSM + tristate "NXP BBNSM RTC support" + select REGMAP_MMIO + depends on ARCH_MXC || COMPILE_TEST + depends on HAS_IOMEM + depends on OF + help + If you say yes here you get support for the NXP BBNSM RTC module. + + This driver can also be built as a module, if so, the module + will be called "rtc-bbnsm". + config RTC_DRV_IMX_SC depends on IMX_SCU depends on HAVE_ARM_SMCCC diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index d3c042dcbc73..0f11027a7388 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_RTC_DRV_ASPEED) += rtc-aspeed.o obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o +obj-$(CONFIG_RTC_DRV_BBNSM) += rtc-nxp-bbnsm.o obj-$(CONFIG_RTC_DRV_BD70528) += rtc-bd70528.o obj-$(CONFIG_RTC_DRV_BQ32K) += rtc-bq32k.o obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o diff --git a/drivers/rtc/rtc-nxp-bbnsm.c b/drivers/rtc/rtc-nxp-bbnsm.c new file mode 100644 index 000000000000..4704a7901341 --- /dev/null +++ b/drivers/rtc/rtc-nxp-bbnsm.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright 2022 NXP. + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_wakeirq.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +#define BBNSM_CTRL 0x8 +#define BBNSM_INT_EN 0x10 +#define BBNSM_EVENTS 0x14 +#define BBNSM_RTC_LS 0x40 +#define BBNSM_RTC_MS 0x44 +#define BBNSM_TA 0x50 + +#define RTC_EN 0x2 +#define RTC_EN_MSK 0x3 +#define TA_EN (0x2 << 2) +#define TA_DIS (0x1 << 2) +#define TA_EN_MSK (0x3 << 2) +#define RTC_INT_EN 0x2 +#define TA_INT_EN (0x2 << 2) + +#define BBNSM_EVENT_TA (0x2 << 2) + +#define CNTR_TO_SECS_SH 15 + +struct bbnsm_rtc { + struct rtc_device *rtc; + struct regmap *regmap; + int irq; + struct clk *clk; +}; + +static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm) +{ + u32 rtc_msb, rtc_lsb; + unsigned int timeout = 100; + u32 time; + u32 tmp = 0; + + do { + time = tmp; + /* read the msb */ + regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb); + /* read the lsb */ + regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb); + /* convert to seconds */ + tmp = (rtc_msb << 17) | (rtc_lsb >> 15); + } while (tmp != time && --timeout); + + return time; +} + +static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + unsigned long time; + u32 val; + + regmap_read(bbnsm->regmap, BBNSM_CTRL, &val); + if ((val & RTC_EN_MSK) != RTC_EN) { + dev_warn(dev, "RTC is not enabled, time is invalid!\n"); + return -EINVAL; + } + + time = bbnsm_read_counter(bbnsm); + rtc_time64_to_tm(time, tm); + + return 0; +} + +static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + unsigned long time = rtc_tm_to_time64(tm); + + /* disable the RTC first */ + regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0); + + /* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */ + regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH); + regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH)); + + /* Enable the RTC again */ + regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN); + + return 0; +} + +static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + u32 bbnsm_events, bbnsm_ta; + + regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta); + rtc_time64_to_tm(bbnsm_ta, &alrm->time); + + regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events); + alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0; + + return 0; +} + +static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + + /* enable the alarm event */ + regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS); + /* enable the alarm interrupt */ + regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS); + + return 0; +} + +static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + unsigned long time = rtc_tm_to_time64(&alrm->time); + + /* disable the alarm */ + regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN, TA_EN); + + /* write the seconds to TA */ + regmap_write(bbnsm->regmap, BBNSM_TA, time); + + return bbnsm_rtc_alarm_irq_enable(dev, alrm->enabled); +} + +static const struct rtc_class_ops bbnsm_rtc_ops = { + .read_time = bbnsm_rtc_read_time, + .set_time = bbnsm_rtc_set_time, + .read_alarm = bbnsm_rtc_read_alarm, + .set_alarm = bbnsm_rtc_set_alarm, + .alarm_irq_enable = bbnsm_rtc_alarm_irq_enable, +}; + +static irqreturn_t bbnsm_rtc_irq_handler(int irq, void *dev_id) +{ + struct device *dev = dev_id; + struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); + u32 val; + + regmap_read(bbnsm->regmap, BBNSM_EVENTS, &val); + if (val & BBNSM_EVENT_TA) { + bbnsm_rtc_alarm_irq_enable(dev, false); + /* clear the alarm event */ + regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, TA_EN_MSK, BBNSM_EVENT_TA); + rtc_update_irq(bbnsm->rtc, 1, RTC_AF | RTC_IRQF); + + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int bbnsm_rtc_probe(struct platform_device *pdev) +{ + struct bbnsm_rtc *bbnsm; + int ret; + + bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL); + if (!bbnsm) + return -ENOMEM; + + bbnsm->rtc = devm_rtc_allocate_device(&pdev->dev); + + bbnsm->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "nxp,bbnsm-regmap"); + if (IS_ERR(bbnsm->regmap)) { + dev_err(&pdev->dev, "bbnsm get regmap failed\n"); + return PTR_ERR(bbnsm->regmap); + } + + bbnsm->irq = platform_get_irq(pdev, 0); + if (bbnsm->irq < 0) + return bbnsm->irq; + + platform_set_drvdata(pdev, bbnsm); + + /* clear all the pending events */ + regmap_write(bbnsm->regmap, BBNSM_EVENTS, 0x7A); + + device_init_wakeup(&pdev->dev, true); + dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq); + + ret = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_rtc_irq_handler, + IRQF_SHARED, "rtc alarm", &pdev->dev); + if (ret) { + dev_err(&pdev->dev, "failed to request irq %d: %d\n", + bbnsm->irq, ret); + return ret; + } + + bbnsm->rtc->ops = &bbnsm_rtc_ops; + bbnsm->rtc->range_max = U32_MAX; + + return devm_rtc_register_device(bbnsm->rtc); +} + +static const struct of_device_id bbnsm_dt_ids[] = { + { .compatible = "nxp,bbnsm-rtc", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, bbnsm_dt_ids); + +static struct platform_driver bbnsm_rtc_driver = { + .driver = { + .name = "bbnsm_rtc", + .of_match_table = bbnsm_dt_ids, + }, + .probe = bbnsm_rtc_probe, +}; +module_platform_driver(bbnsm_rtc_driver); + +MODULE_AUTHOR("Jacky Bai <ping.bai@xxxxxxx>"); +MODULE_DESCRIPTION("NXP BBNSM RTC Driver"); +MODULE_LICENSE("GPL"); -- 2.37.1