| 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); |