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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Realtek RTD129x RTC4 *5 * Copyright (c) 2017 Andreas Färber6 */7 8#include <linux/clk.h>9#include <linux/io.h>10#include <linux/module.h>11#include <linux/of.h>12#include <linux/of_address.h>13#include <linux/platform_device.h>14#include <linux/rtc.h>15#include <linux/spinlock.h>16 17#define RTD_RTCSEC 0x0018#define RTD_RTCMIN 0x0419#define RTD_RTCHR 0x0820#define RTD_RTCDATE1 0x0c21#define RTD_RTCDATE2 0x1022#define RTD_RTCACR 0x2823#define RTD_RTCEN 0x2c24#define RTD_RTCCR 0x3025 26#define RTD_RTCSEC_RTCSEC_MASK 0x7f27 28#define RTD_RTCMIN_RTCMIN_MASK 0x3f29 30#define RTD_RTCHR_RTCHR_MASK 0x1f31 32#define RTD_RTCDATE1_RTCDATE1_MASK 0xff33 34#define RTD_RTCDATE2_RTCDATE2_MASK 0x7f35 36#define RTD_RTCACR_RTCPWR BIT(7)37 38#define RTD_RTCEN_RTCEN_MASK 0xff39 40#define RTD_RTCCR_RTCRST BIT(6)41 42struct rtd119x_rtc {43 void __iomem *base;44 struct clk *clk;45 struct rtc_device *rtcdev;46 unsigned int base_year;47};48 49static inline int rtd119x_rtc_days_in_year(int year)50{51 return 365 + (is_leap_year(year) ? 1 : 0);52}53 54static void rtd119x_rtc_reset(struct device *dev)55{56 struct rtd119x_rtc *data = dev_get_drvdata(dev);57 u32 val;58 59 val = readl_relaxed(data->base + RTD_RTCCR);60 val |= RTD_RTCCR_RTCRST;61 writel_relaxed(val, data->base + RTD_RTCCR);62 63 val &= ~RTD_RTCCR_RTCRST;64 writel(val, data->base + RTD_RTCCR);65}66 67static void rtd119x_rtc_set_enabled(struct device *dev, bool enable)68{69 struct rtd119x_rtc *data = dev_get_drvdata(dev);70 u32 val;71 72 val = readl_relaxed(data->base + RTD_RTCEN);73 if (enable) {74 if ((val & RTD_RTCEN_RTCEN_MASK) == 0x5a)75 return;76 writel_relaxed(0x5a, data->base + RTD_RTCEN);77 } else {78 writel_relaxed(0, data->base + RTD_RTCEN);79 }80}81 82static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm)83{84 struct rtd119x_rtc *data = dev_get_drvdata(dev);85 s32 day;86 u32 sec;87 unsigned int year;88 int tries = 0;89 90 while (true) {91 tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;92 tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK;93 tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK;94 day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK;95 day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8;96 sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;97 tries++;98 99 if (sec == tm->tm_sec)100 break;101 102 if (tries >= 3)103 return -EINVAL;104 }105 if (tries > 1)106 dev_dbg(dev, "%s: needed %i tries\n", __func__, tries);107 108 year = data->base_year;109 while (day >= rtd119x_rtc_days_in_year(year)) {110 day -= rtd119x_rtc_days_in_year(year);111 year++;112 }113 tm->tm_year = year - 1900;114 tm->tm_yday = day;115 116 tm->tm_mon = 0;117 while (day >= rtc_month_days(tm->tm_mon, year)) {118 day -= rtc_month_days(tm->tm_mon, year);119 tm->tm_mon++;120 }121 tm->tm_mday = day + 1;122 123 return 0;124}125 126static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm)127{128 struct rtd119x_rtc *data = dev_get_drvdata(dev);129 unsigned int day;130 int i;131 132 if (1900 + tm->tm_year < data->base_year)133 return -EINVAL;134 135 day = 0;136 for (i = data->base_year; i < 1900 + tm->tm_year; i++)137 day += rtd119x_rtc_days_in_year(i);138 139 day += tm->tm_yday;140 if (day > 0x7fff)141 return -EINVAL;142 143 rtd119x_rtc_set_enabled(dev, false);144 145 writel_relaxed((tm->tm_sec << 1) & RTD_RTCSEC_RTCSEC_MASK, data->base + RTD_RTCSEC);146 writel_relaxed(tm->tm_min & RTD_RTCMIN_RTCMIN_MASK, data->base + RTD_RTCMIN);147 writel_relaxed(tm->tm_hour & RTD_RTCHR_RTCHR_MASK, data->base + RTD_RTCHR);148 writel_relaxed(day & RTD_RTCDATE1_RTCDATE1_MASK, data->base + RTD_RTCDATE1);149 writel_relaxed((day >> 8) & RTD_RTCDATE2_RTCDATE2_MASK, data->base + RTD_RTCDATE2);150 151 rtd119x_rtc_set_enabled(dev, true);152 153 return 0;154}155 156static const struct rtc_class_ops rtd119x_rtc_ops = {157 .read_time = rtd119x_rtc_read_time,158 .set_time = rtd119x_rtc_set_time,159};160 161static const struct of_device_id rtd119x_rtc_dt_ids[] = {162 { .compatible = "realtek,rtd1295-rtc" },163 { }164};165 166static int rtd119x_rtc_probe(struct platform_device *pdev)167{168 struct rtd119x_rtc *data;169 u32 val;170 int ret;171 172 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);173 if (!data)174 return -ENOMEM;175 176 platform_set_drvdata(pdev, data);177 data->base_year = 2014;178 179 data->base = devm_platform_ioremap_resource(pdev, 0);180 if (IS_ERR(data->base))181 return PTR_ERR(data->base);182 183 data->clk = of_clk_get(pdev->dev.of_node, 0);184 if (IS_ERR(data->clk))185 return PTR_ERR(data->clk);186 187 ret = clk_prepare_enable(data->clk);188 if (ret) {189 clk_put(data->clk);190 return ret;191 }192 193 val = readl_relaxed(data->base + RTD_RTCACR);194 if (!(val & RTD_RTCACR_RTCPWR)) {195 writel_relaxed(RTD_RTCACR_RTCPWR, data->base + RTD_RTCACR);196 197 rtd119x_rtc_reset(&pdev->dev);198 199 writel_relaxed(0, data->base + RTD_RTCMIN);200 writel_relaxed(0, data->base + RTD_RTCHR);201 writel_relaxed(0, data->base + RTD_RTCDATE1);202 writel_relaxed(0, data->base + RTD_RTCDATE2);203 }204 205 rtd119x_rtc_set_enabled(&pdev->dev, true);206 207 data->rtcdev = devm_rtc_device_register(&pdev->dev, "rtc",208 &rtd119x_rtc_ops, THIS_MODULE);209 if (IS_ERR(data->rtcdev)) {210 dev_err(&pdev->dev, "failed to register rtc device");211 clk_disable_unprepare(data->clk);212 clk_put(data->clk);213 return PTR_ERR(data->rtcdev);214 }215 216 return 0;217}218 219static void rtd119x_rtc_remove(struct platform_device *pdev)220{221 struct rtd119x_rtc *data = platform_get_drvdata(pdev);222 223 rtd119x_rtc_set_enabled(&pdev->dev, false);224 225 clk_disable_unprepare(data->clk);226 clk_put(data->clk);227}228 229static struct platform_driver rtd119x_rtc_driver = {230 .probe = rtd119x_rtc_probe,231 .remove_new = rtd119x_rtc_remove,232 .driver = {233 .name = "rtd1295-rtc",234 .of_match_table = rtd119x_rtc_dt_ids,235 },236};237builtin_platform_driver(rtd119x_rtc_driver);238