1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Faraday Technology FTRTC010 driver 4 * 5 * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com> 6 * 7 * Original code for older kernel 2.6.15 are from Stormlinksemi 8 * first update from Janos Laube for > 2.6.29 kernels 9 * 10 * checkpatch fixes and usage of rtc-lib code 11 * 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 25 MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>"); 26 MODULE_DESCRIPTION("RTC driver for Gemini SoC"); 27 MODULE_LICENSE("GPL"); 28 MODULE_ALIAS("platform:" DRV_NAME); 29 30 struct 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 38 enum 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 50 static 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) broken 57 * We can't read/write directly the time from RTC registers. 58 * We must do some "offset" calculation to get the real time 59 * 60 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does 61 * the same thing, without the rtc-lib.c calls. 62 */ 63 64 static 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 84 static 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 } 104 105 static const struct rtc_class_ops ftrtc010_rtc_ops = { 106 .read_time = ftrtc010_rtc_read_time, 107 .set_time = ftrtc010_rtc_set_time, 108 }; 109 110 static 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 return ret; 141 } 142 } 143 144 rtc->rtc_irq = platform_get_irq(pdev, 0); 145 if (rtc->rtc_irq < 0) 146 return rtc->rtc_irq; 147 148 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 149 if (!res) 150 return -ENODEV; 151 152 rtc->rtc_base = devm_ioremap(dev, res->start, 153 resource_size(res)); 154 if (!rtc->rtc_base) 155 return -ENOMEM; 156 157 rtc->rtc_dev = devm_rtc_allocate_device(dev); 158 if (IS_ERR(rtc->rtc_dev)) 159 return PTR_ERR(rtc->rtc_dev); 160 161 rtc->rtc_dev->ops = &ftrtc010_rtc_ops; 162 163 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); 164 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); 165 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); 166 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); 167 168 rtc->rtc_dev->range_min = (u64)days * 86400 + hour * 3600 + 169 min * 60 + sec; 170 rtc->rtc_dev->range_max = U32_MAX + rtc->rtc_dev->range_min; 171 172 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt, 173 IRQF_SHARED, pdev->name, dev); 174 if (unlikely(ret)) 175 return ret; 176 177 return devm_rtc_register_device(rtc->rtc_dev); 178 } 179 180 static int ftrtc010_rtc_remove(struct platform_device *pdev) 181 { 182 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev); 183 184 if (!IS_ERR(rtc->extclk)) 185 clk_disable_unprepare(rtc->extclk); 186 if (!IS_ERR(rtc->pclk)) 187 clk_disable_unprepare(rtc->pclk); 188 189 return 0; 190 } 191 192 static const struct of_device_id ftrtc010_rtc_dt_match[] = { 193 { .compatible = "cortina,gemini-rtc" }, 194 { .compatible = "faraday,ftrtc010" }, 195 { } 196 }; 197 MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match); 198 199 static struct platform_driver ftrtc010_rtc_driver = { 200 .driver = { 201 .name = DRV_NAME, 202 .of_match_table = ftrtc010_rtc_dt_match, 203 }, 204 .probe = ftrtc010_rtc_probe, 205 .remove = ftrtc010_rtc_remove, 206 }; 207 208 module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe); 209