Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Gemini OnChip RTC |
| 3 | * |
| 4 | * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * Original code for older kernel 2.6.15 are from Stormlinksemi |
| 17 | * first update from Janos Laube for > 2.6.29 kernels |
| 18 | * |
| 19 | * checkpatch fixes and usage of rtc-lib code |
| 20 | * Hans Ulli Kroll <ulli.kroll@googlemail.com> |
| 21 | */ |
| 22 | |
| 23 | #include <linux/rtc.h> |
| 24 | #include <linux/io.h> |
| 25 | #include <linux/slab.h> |
| 26 | #include <linux/platform_device.h> |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/module.h> |
| 29 | |
| 30 | #define DRV_NAME "rtc-gemini" |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 31 | |
| 32 | MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>"); |
| 33 | MODULE_DESCRIPTION("RTC driver for Gemini SoC"); |
| 34 | MODULE_LICENSE("GPL"); |
| 35 | MODULE_ALIAS("platform:" DRV_NAME); |
| 36 | |
| 37 | struct gemini_rtc { |
| 38 | struct rtc_device *rtc_dev; |
| 39 | void __iomem *rtc_base; |
| 40 | int rtc_irq; |
| 41 | }; |
| 42 | |
| 43 | enum gemini_rtc_offsets { |
| 44 | GEMINI_RTC_SECOND = 0x00, |
| 45 | GEMINI_RTC_MINUTE = 0x04, |
| 46 | GEMINI_RTC_HOUR = 0x08, |
| 47 | GEMINI_RTC_DAYS = 0x0C, |
| 48 | GEMINI_RTC_ALARM_SECOND = 0x10, |
| 49 | GEMINI_RTC_ALARM_MINUTE = 0x14, |
| 50 | GEMINI_RTC_ALARM_HOUR = 0x18, |
| 51 | GEMINI_RTC_RECORD = 0x1C, |
| 52 | GEMINI_RTC_CR = 0x20 |
| 53 | }; |
| 54 | |
| 55 | static irqreturn_t gemini_rtc_interrupt(int irq, void *dev) |
| 56 | { |
| 57 | return IRQ_HANDLED; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * Looks like the RTC in the Gemini SoC is (totaly) broken |
| 62 | * We can't read/write directly the time from RTC registers. |
| 63 | * We must do some "offset" calculation to get the real time |
| 64 | * |
| 65 | * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does |
| 66 | * the same thing, without the rtc-lib.c calls. |
| 67 | */ |
| 68 | |
| 69 | static int gemini_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 70 | { |
| 71 | struct gemini_rtc *rtc = dev_get_drvdata(dev); |
| 72 | |
| 73 | unsigned int days, hour, min, sec; |
| 74 | unsigned long offset, time; |
| 75 | |
| 76 | sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); |
| 77 | min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); |
| 78 | hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); |
| 79 | days = readl(rtc->rtc_base + GEMINI_RTC_DAYS); |
| 80 | offset = readl(rtc->rtc_base + GEMINI_RTC_RECORD); |
| 81 | |
| 82 | time = offset + days * 86400 + hour * 3600 + min * 60 + sec; |
| 83 | |
| 84 | rtc_time_to_tm(time, tm); |
| 85 | |
| 86 | return 0; |
| 87 | } |
| 88 | |
| 89 | static int gemini_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 90 | { |
| 91 | struct gemini_rtc *rtc = dev_get_drvdata(dev); |
| 92 | unsigned int sec, min, hour, day; |
| 93 | unsigned long offset, time; |
| 94 | |
| 95 | if (tm->tm_year >= 2148) /* EPOCH Year + 179 */ |
| 96 | return -EINVAL; |
| 97 | |
| 98 | rtc_tm_to_time(tm, &time); |
| 99 | |
| 100 | sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); |
| 101 | min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); |
| 102 | hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); |
| 103 | day = readl(rtc->rtc_base + GEMINI_RTC_DAYS); |
| 104 | |
| 105 | offset = time - (day * 86400 + hour * 3600 + min * 60 + sec); |
| 106 | |
| 107 | writel(offset, rtc->rtc_base + GEMINI_RTC_RECORD); |
| 108 | writel(0x01, rtc->rtc_base + GEMINI_RTC_CR); |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
Julia Lawall | 34c7b3a | 2016-08-31 10:05:25 +0200 | [diff] [blame] | 113 | static const struct rtc_class_ops gemini_rtc_ops = { |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 114 | .read_time = gemini_rtc_read_time, |
| 115 | .set_time = gemini_rtc_set_time, |
| 116 | }; |
| 117 | |
| 118 | static int gemini_rtc_probe(struct platform_device *pdev) |
| 119 | { |
| 120 | struct gemini_rtc *rtc; |
| 121 | struct device *dev = &pdev->dev; |
| 122 | struct resource *res; |
| 123 | int ret; |
| 124 | |
| 125 | rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); |
| 126 | if (unlikely(!rtc)) |
| 127 | return -ENOMEM; |
| 128 | platform_set_drvdata(pdev, rtc); |
| 129 | |
| 130 | res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| 131 | if (!res) |
| 132 | return -ENODEV; |
| 133 | |
| 134 | rtc->rtc_irq = res->start; |
| 135 | |
| 136 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 137 | if (!res) |
| 138 | return -ENODEV; |
| 139 | |
| 140 | rtc->rtc_base = devm_ioremap(dev, res->start, |
kbuild test robot | 45b4c85 | 2015-06-13 21:16:56 +0800 | [diff] [blame] | 141 | resource_size(res)); |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 142 | |
| 143 | ret = devm_request_irq(dev, rtc->rtc_irq, gemini_rtc_interrupt, |
| 144 | IRQF_SHARED, pdev->name, dev); |
| 145 | if (unlikely(ret)) |
| 146 | return ret; |
| 147 | |
| 148 | rtc->rtc_dev = rtc_device_register(pdev->name, dev, |
| 149 | &gemini_rtc_ops, THIS_MODULE); |
kbuild test robot | 202cc98 | 2015-07-31 15:01:04 +0530 | [diff] [blame] | 150 | return PTR_ERR_OR_ZERO(rtc->rtc_dev); |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | static int gemini_rtc_remove(struct platform_device *pdev) |
| 154 | { |
| 155 | struct gemini_rtc *rtc = platform_get_drvdata(pdev); |
| 156 | |
| 157 | rtc_device_unregister(rtc->rtc_dev); |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | static struct platform_driver gemini_rtc_driver = { |
| 163 | .driver = { |
| 164 | .name = DRV_NAME, |
Hans Ulli Kroll | 98a9bb5 | 2015-05-20 17:49:31 +0200 | [diff] [blame] | 165 | }, |
| 166 | .probe = gemini_rtc_probe, |
| 167 | .remove = gemini_rtc_remove, |
| 168 | }; |
| 169 | |
| 170 | module_platform_driver_probe(gemini_rtc_driver, gemini_rtc_probe); |