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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Faraday Technology FTRTC010 driver4 *5 * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>6 *7 * Original code for older kernel 2.6.15 are from Stormlinksemi8 * first update from Janos Laube for > 2.6.29 kernels9 *10 * checkpatch fixes and usage of rtc-lib code11 * Hans Ulli Kroll <ulli.kroll@googlemail.com>12 */13 14#include <linux/rtc.h>15#include <linux/io.h>16#include <linux/slab.h>17#include <linux/platform_device.h>18#include <linux/kernel.h>19#include <linux/module.h>20#include <linux/mod_devicetable.h>21#include <linux/clk.h>22 23#define DRV_NAME "rtc-ftrtc010"24 25MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");26MODULE_DESCRIPTION("RTC driver for Gemini SoC");27MODULE_LICENSE("GPL");28MODULE_ALIAS("platform:" DRV_NAME);29 30struct ftrtc010_rtc {31 struct rtc_device *rtc_dev;32 void __iomem *rtc_base;33 int rtc_irq;34 struct clk *pclk;35 struct clk *extclk;36};37 38enum ftrtc010_rtc_offsets {39 FTRTC010_RTC_SECOND = 0x00,40 FTRTC010_RTC_MINUTE = 0x04,41 FTRTC010_RTC_HOUR = 0x08,42 FTRTC010_RTC_DAYS = 0x0C,43 FTRTC010_RTC_ALARM_SECOND = 0x10,44 FTRTC010_RTC_ALARM_MINUTE = 0x14,45 FTRTC010_RTC_ALARM_HOUR = 0x18,46 FTRTC010_RTC_RECORD = 0x1C,47 FTRTC010_RTC_CR = 0x20,48};49 50static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)51{52 return IRQ_HANDLED;53}54 55/*56 * Looks like the RTC in the Gemini SoC is (totaly) broken57 * We can't read/write directly the time from RTC registers.58 * We must do some "offset" calculation to get the real time59 *60 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does61 * the same thing, without the rtc-lib.c calls.62 */63 64static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)65{66 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);67 68 u32 days, hour, min, sec, offset;69 timeu64_t time;70 71 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);72 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);73 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);74 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);75 offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);76 77 time = offset + days * 86400 + hour * 3600 + min * 60 + sec;78 79 rtc_time64_to_tm(time, tm);80 81 return 0;82}83 84static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)85{86 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);87 u32 sec, min, hour, day, offset;88 timeu64_t time;89 90 time = rtc_tm_to_time64(tm);91 92 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);93 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);94 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);95 day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);96 97 offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);98 99 writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);100 writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);101 102 return 0;103}104 105static const struct rtc_class_ops ftrtc010_rtc_ops = {106 .read_time = ftrtc010_rtc_read_time,107 .set_time = ftrtc010_rtc_set_time,108};109 110static int ftrtc010_rtc_probe(struct platform_device *pdev)111{112 u32 days, hour, min, sec;113 struct ftrtc010_rtc *rtc;114 struct device *dev = &pdev->dev;115 struct resource *res;116 int ret;117 118 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);119 if (unlikely(!rtc))120 return -ENOMEM;121 platform_set_drvdata(pdev, rtc);122 123 rtc->pclk = devm_clk_get(dev, "PCLK");124 if (IS_ERR(rtc->pclk)) {125 dev_err(dev, "could not get PCLK\n");126 } else {127 ret = clk_prepare_enable(rtc->pclk);128 if (ret) {129 dev_err(dev, "failed to enable PCLK\n");130 return ret;131 }132 }133 rtc->extclk = devm_clk_get(dev, "EXTCLK");134 if (IS_ERR(rtc->extclk)) {135 dev_err(dev, "could not get EXTCLK\n");136 } else {137 ret = clk_prepare_enable(rtc->extclk);138 if (ret) {139 dev_err(dev, "failed to enable EXTCLK\n");140 goto err_disable_pclk;141 }142 }143 144 rtc->rtc_irq = platform_get_irq(pdev, 0);145 if (rtc->rtc_irq < 0) {146 ret = rtc->rtc_irq;147 goto err_disable_extclk;148 }149 150 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);151 if (!res) {152 ret = -ENODEV;153 goto err_disable_extclk;154 }155 156 rtc->rtc_base = devm_ioremap(dev, res->start,157 resource_size(res));158 if (!rtc->rtc_base) {159 ret = -ENOMEM;160 goto err_disable_extclk;161 }162 163 rtc->rtc_dev = devm_rtc_allocate_device(dev);164 if (IS_ERR(rtc->rtc_dev)) {165 ret = PTR_ERR(rtc->rtc_dev);166 goto err_disable_extclk;167 }168 169 rtc->rtc_dev->ops = &ftrtc010_rtc_ops;170 171 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);172 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);173 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);174 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);175 176 rtc->rtc_dev->range_min = (u64)days * 86400 + hour * 3600 +177 min * 60 + sec;178 rtc->rtc_dev->range_max = U32_MAX + rtc->rtc_dev->range_min;179 180 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,181 IRQF_SHARED, pdev->name, dev);182 if (unlikely(ret))183 goto err_disable_extclk;184 185 return devm_rtc_register_device(rtc->rtc_dev);186 187err_disable_extclk:188 clk_disable_unprepare(rtc->extclk);189err_disable_pclk:190 clk_disable_unprepare(rtc->pclk);191 return ret;192}193 194static void ftrtc010_rtc_remove(struct platform_device *pdev)195{196 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);197 198 if (!IS_ERR(rtc->extclk))199 clk_disable_unprepare(rtc->extclk);200 if (!IS_ERR(rtc->pclk))201 clk_disable_unprepare(rtc->pclk);202}203 204static const struct of_device_id ftrtc010_rtc_dt_match[] = {205 { .compatible = "cortina,gemini-rtc" },206 { .compatible = "faraday,ftrtc010" },207 { }208};209MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);210 211static struct platform_driver ftrtc010_rtc_driver = {212 .driver = {213 .name = DRV_NAME,214 .of_match_table = ftrtc010_rtc_dt_match,215 },216 .probe = ftrtc010_rtc_probe,217 .remove_new = ftrtc010_rtc_remove,218};219 220module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);221