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 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); 186 187 err_disable_extclk: 188 clk_disable_unprepare(rtc->extclk); 189 err_disable_pclk: 190 clk_disable_unprepare(rtc->pclk); 191 return ret; 192 } 193 194 static int 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 return 0; 204 } 205 206 static const struct of_device_id ftrtc010_rtc_dt_match[] = { 207 { .compatible = "cortina,gemini-rtc" }, 208 { .compatible = "faraday,ftrtc010" }, 209 { } 210 }; 211 MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match); 212 213 static struct platform_driver ftrtc010_rtc_driver = { 214 .driver = { 215 .name = DRV_NAME, 216 .of_match_table = ftrtc010_rtc_dt_match, 217 }, 218 .probe = ftrtc010_rtc_probe, 219 .remove = ftrtc010_rtc_remove, 220 }; 221 222 module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe); 223