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 void __iomem *rtc_base; 32 int rtc_irq; 33 struct clk *pclk; 34 struct clk *extclk; 35 }; 36 37 enum ftrtc010_rtc_offsets { 38 FTRTC010_RTC_SECOND = 0x00, 39 FTRTC010_RTC_MINUTE = 0x04, 40 FTRTC010_RTC_HOUR = 0x08, 41 FTRTC010_RTC_DAYS = 0x0C, 42 FTRTC010_RTC_ALARM_SECOND = 0x10, 43 FTRTC010_RTC_ALARM_MINUTE = 0x14, 44 FTRTC010_RTC_ALARM_HOUR = 0x18, 45 FTRTC010_RTC_RECORD = 0x1C, 46 FTRTC010_RTC_CR = 0x20, 47 }; 48 49 static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev) 50 { 51 return IRQ_HANDLED; 52 } 53 54 /* 55 * Looks like the RTC in the Gemini SoC is (totaly) broken 56 * We can't read/write directly the time from RTC registers. 57 * We must do some "offset" calculation to get the real time 58 * 59 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does 60 * the same thing, without the rtc-lib.c calls. 61 */ 62 63 static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm) 64 { 65 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev); 66 67 u32 days, hour, min, sec, offset; 68 timeu64_t time; 69 70 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); 71 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); 72 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); 73 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); 74 offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD); 75 76 time = offset + days * 86400 + hour * 3600 + min * 60 + sec; 77 78 rtc_time64_to_tm(time, tm); 79 80 return 0; 81 } 82 83 static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm) 84 { 85 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev); 86 u32 sec, min, hour, day, offset; 87 timeu64_t time; 88 89 time = rtc_tm_to_time64(tm); 90 91 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); 92 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); 93 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); 94 day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); 95 96 offset = time - (day * 86400 + hour * 3600 + min * 60 + sec); 97 98 writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD); 99 writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR); 100 101 return 0; 102 } 103 104 static const struct rtc_class_ops ftrtc010_rtc_ops = { 105 .read_time = ftrtc010_rtc_read_time, 106 .set_time = ftrtc010_rtc_set_time, 107 }; 108 109 static int ftrtc010_rtc_probe(struct platform_device *pdev) 110 { 111 u32 days, hour, min, sec; 112 struct ftrtc010_rtc *rtc; 113 struct device *dev = &pdev->dev; 114 struct resource *res; 115 struct rtc_device *rtc_dev; 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_dev = devm_rtc_allocate_device(dev); 164 if (IS_ERR(rtc_dev)) { 165 ret = PTR_ERR(rtc_dev); 166 goto err_disable_extclk; 167 } 168 169 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_dev->range_min = (u64)days * 86400 + hour * 3600 + min * 60 + sec; 177 rtc_dev->range_max = U32_MAX + rtc_dev->range_min; 178 179 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt, 180 IRQF_SHARED, pdev->name, dev); 181 if (unlikely(ret)) 182 goto err_disable_extclk; 183 184 return devm_rtc_register_device(rtc_dev); 185 186 err_disable_extclk: 187 clk_disable_unprepare(rtc->extclk); 188 err_disable_pclk: 189 clk_disable_unprepare(rtc->pclk); 190 return ret; 191 } 192 193 static void ftrtc010_rtc_remove(struct platform_device *pdev) 194 { 195 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev); 196 197 if (!IS_ERR(rtc->extclk)) 198 clk_disable_unprepare(rtc->extclk); 199 if (!IS_ERR(rtc->pclk)) 200 clk_disable_unprepare(rtc->pclk); 201 } 202 203 static const struct of_device_id ftrtc010_rtc_dt_match[] = { 204 { .compatible = "cortina,gemini-rtc" }, 205 { .compatible = "faraday,ftrtc010" }, 206 { } 207 }; 208 MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match); 209 210 static struct platform_driver ftrtc010_rtc_driver = { 211 .driver = { 212 .name = DRV_NAME, 213 .of_match_table = ftrtc010_rtc_dt_match, 214 }, 215 .probe = ftrtc010_rtc_probe, 216 .remove = ftrtc010_rtc_remove, 217 }; 218 219 module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe); 220