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1// SPDX-License-Identifier: GPL-2.0+2//3// Copyright 2022 NXP.4 5#include <linux/init.h>6#include <linux/io.h>7#include <linux/kernel.h>8#include <linux/mfd/syscon.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/pm_wakeirq.h>13#include <linux/regmap.h>14#include <linux/rtc.h>15 16#define BBNSM_CTRL 0x817#define BBNSM_INT_EN 0x1018#define BBNSM_EVENTS 0x1419#define BBNSM_RTC_LS 0x4020#define BBNSM_RTC_MS 0x4421#define BBNSM_TA 0x5022 23#define RTC_EN 0x224#define RTC_EN_MSK 0x325#define TA_EN (0x2 << 2)26#define TA_DIS (0x1 << 2)27#define TA_EN_MSK (0x3 << 2)28#define RTC_INT_EN 0x229#define TA_INT_EN (0x2 << 2)30 31#define BBNSM_EVENT_TA (0x2 << 2)32 33#define CNTR_TO_SECS_SH 1534 35struct bbnsm_rtc {36 struct rtc_device *rtc;37 struct regmap *regmap;38 int irq;39 struct clk *clk;40};41 42static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm)43{44 u32 rtc_msb, rtc_lsb;45 unsigned int timeout = 100;46 u32 time;47 u32 tmp = 0;48 49 do {50 time = tmp;51 /* read the msb */52 regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb);53 /* read the lsb */54 regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb);55 /* convert to seconds */56 tmp = (rtc_msb << 17) | (rtc_lsb >> 15);57 } while (tmp != time && --timeout);58 59 return time;60}61 62static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm)63{64 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);65 unsigned long time;66 u32 val;67 68 regmap_read(bbnsm->regmap, BBNSM_CTRL, &val);69 if ((val & RTC_EN_MSK) != RTC_EN)70 return -EINVAL;71 72 time = bbnsm_read_counter(bbnsm);73 rtc_time64_to_tm(time, tm);74 75 return 0;76}77 78static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm)79{80 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);81 unsigned long time = rtc_tm_to_time64(tm);82 83 /* disable the RTC first */84 regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0);85 86 /* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */87 regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH);88 regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH));89 90 /* Enable the RTC again */91 regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN);92 93 return 0;94}95 96static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)97{98 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);99 u32 bbnsm_events, bbnsm_ta;100 101 regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta);102 rtc_time64_to_tm(bbnsm_ta, &alrm->time);103 104 regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events);105 alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0;106 107 return 0;108}109 110static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)111{112 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);113 114 /* enable the alarm event */115 regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS);116 /* enable the alarm interrupt */117 regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS);118 119 return 0;120}121 122static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)123{124 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);125 unsigned long time = rtc_tm_to_time64(&alrm->time);126 127 /* disable the alarm */128 regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN, TA_EN);129 130 /* write the seconds to TA */131 regmap_write(bbnsm->regmap, BBNSM_TA, time);132 133 return bbnsm_rtc_alarm_irq_enable(dev, alrm->enabled);134}135 136static const struct rtc_class_ops bbnsm_rtc_ops = {137 .read_time = bbnsm_rtc_read_time,138 .set_time = bbnsm_rtc_set_time,139 .read_alarm = bbnsm_rtc_read_alarm,140 .set_alarm = bbnsm_rtc_set_alarm,141 .alarm_irq_enable = bbnsm_rtc_alarm_irq_enable,142};143 144static irqreturn_t bbnsm_rtc_irq_handler(int irq, void *dev_id)145{146 struct device *dev = dev_id;147 struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);148 u32 val;149 150 regmap_read(bbnsm->regmap, BBNSM_EVENTS, &val);151 if (val & BBNSM_EVENT_TA) {152 bbnsm_rtc_alarm_irq_enable(dev, false);153 /* clear the alarm event */154 regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, TA_EN_MSK, BBNSM_EVENT_TA);155 rtc_update_irq(bbnsm->rtc, 1, RTC_AF | RTC_IRQF);156 157 return IRQ_HANDLED;158 }159 160 return IRQ_NONE;161}162 163static int bbnsm_rtc_probe(struct platform_device *pdev)164{165 struct device_node *np = pdev->dev.of_node;166 struct bbnsm_rtc *bbnsm;167 int ret;168 169 bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);170 if (!bbnsm)171 return -ENOMEM;172 173 bbnsm->rtc = devm_rtc_allocate_device(&pdev->dev);174 if (IS_ERR(bbnsm->rtc))175 return PTR_ERR(bbnsm->rtc);176 177 bbnsm->regmap = syscon_node_to_regmap(np->parent);178 if (IS_ERR(bbnsm->regmap)) {179 dev_dbg(&pdev->dev, "bbnsm get regmap failed\n");180 return PTR_ERR(bbnsm->regmap);181 }182 183 bbnsm->irq = platform_get_irq(pdev, 0);184 if (bbnsm->irq < 0)185 return bbnsm->irq;186 187 platform_set_drvdata(pdev, bbnsm);188 189 /* clear all the pending events */190 regmap_write(bbnsm->regmap, BBNSM_EVENTS, 0x7A);191 192 device_init_wakeup(&pdev->dev, true);193 dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);194 195 ret = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_rtc_irq_handler,196 IRQF_SHARED, "rtc alarm", &pdev->dev);197 if (ret) {198 dev_err(&pdev->dev, "failed to request irq %d: %d\n",199 bbnsm->irq, ret);200 return ret;201 }202 203 bbnsm->rtc->ops = &bbnsm_rtc_ops;204 bbnsm->rtc->range_max = U32_MAX;205 206 return devm_rtc_register_device(bbnsm->rtc);207}208 209static const struct of_device_id bbnsm_dt_ids[] = {210 { .compatible = "nxp,imx93-bbnsm-rtc" },211 { /* sentinel */ },212};213MODULE_DEVICE_TABLE(of, bbnsm_dt_ids);214 215static struct platform_driver bbnsm_rtc_driver = {216 .driver = {217 .name = "bbnsm_rtc",218 .of_match_table = bbnsm_dt_ids,219 },220 .probe = bbnsm_rtc_probe,221};222module_platform_driver(bbnsm_rtc_driver);223 224MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");225MODULE_DESCRIPTION("NXP BBNSM RTC Driver");226MODULE_LICENSE("GPL");227