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98a9bb5b HUK |
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" | |
31 | #define DRV_VERSION "0.2" | |
32 | ||
33 | MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>"); | |
34 | MODULE_DESCRIPTION("RTC driver for Gemini SoC"); | |
35 | MODULE_LICENSE("GPL"); | |
36 | MODULE_ALIAS("platform:" DRV_NAME); | |
37 | ||
38 | struct gemini_rtc { | |
39 | struct rtc_device *rtc_dev; | |
40 | void __iomem *rtc_base; | |
41 | int rtc_irq; | |
42 | }; | |
43 | ||
44 | enum gemini_rtc_offsets { | |
45 | GEMINI_RTC_SECOND = 0x00, | |
46 | GEMINI_RTC_MINUTE = 0x04, | |
47 | GEMINI_RTC_HOUR = 0x08, | |
48 | GEMINI_RTC_DAYS = 0x0C, | |
49 | GEMINI_RTC_ALARM_SECOND = 0x10, | |
50 | GEMINI_RTC_ALARM_MINUTE = 0x14, | |
51 | GEMINI_RTC_ALARM_HOUR = 0x18, | |
52 | GEMINI_RTC_RECORD = 0x1C, | |
53 | GEMINI_RTC_CR = 0x20 | |
54 | }; | |
55 | ||
56 | static irqreturn_t gemini_rtc_interrupt(int irq, void *dev) | |
57 | { | |
58 | return IRQ_HANDLED; | |
59 | } | |
60 | ||
61 | /* | |
62 | * Looks like the RTC in the Gemini SoC is (totaly) broken | |
63 | * We can't read/write directly the time from RTC registers. | |
64 | * We must do some "offset" calculation to get the real time | |
65 | * | |
66 | * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does | |
67 | * the same thing, without the rtc-lib.c calls. | |
68 | */ | |
69 | ||
70 | static int gemini_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
71 | { | |
72 | struct gemini_rtc *rtc = dev_get_drvdata(dev); | |
73 | ||
74 | unsigned int days, hour, min, sec; | |
75 | unsigned long offset, time; | |
76 | ||
77 | sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); | |
78 | min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); | |
79 | hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); | |
80 | days = readl(rtc->rtc_base + GEMINI_RTC_DAYS); | |
81 | offset = readl(rtc->rtc_base + GEMINI_RTC_RECORD); | |
82 | ||
83 | time = offset + days * 86400 + hour * 3600 + min * 60 + sec; | |
84 | ||
85 | rtc_time_to_tm(time, tm); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | static int gemini_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
91 | { | |
92 | struct gemini_rtc *rtc = dev_get_drvdata(dev); | |
93 | unsigned int sec, min, hour, day; | |
94 | unsigned long offset, time; | |
95 | ||
96 | if (tm->tm_year >= 2148) /* EPOCH Year + 179 */ | |
97 | return -EINVAL; | |
98 | ||
99 | rtc_tm_to_time(tm, &time); | |
100 | ||
101 | sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND); | |
102 | min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE); | |
103 | hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR); | |
104 | day = readl(rtc->rtc_base + GEMINI_RTC_DAYS); | |
105 | ||
106 | offset = time - (day * 86400 + hour * 3600 + min * 60 + sec); | |
107 | ||
108 | writel(offset, rtc->rtc_base + GEMINI_RTC_RECORD); | |
109 | writel(0x01, rtc->rtc_base + GEMINI_RTC_CR); | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | static struct rtc_class_ops gemini_rtc_ops = { | |
115 | .read_time = gemini_rtc_read_time, | |
116 | .set_time = gemini_rtc_set_time, | |
117 | }; | |
118 | ||
119 | static int gemini_rtc_probe(struct platform_device *pdev) | |
120 | { | |
121 | struct gemini_rtc *rtc; | |
122 | struct device *dev = &pdev->dev; | |
123 | struct resource *res; | |
124 | int ret; | |
125 | ||
126 | rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); | |
127 | if (unlikely(!rtc)) | |
128 | return -ENOMEM; | |
129 | platform_set_drvdata(pdev, rtc); | |
130 | ||
131 | res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
132 | if (!res) | |
133 | return -ENODEV; | |
134 | ||
135 | rtc->rtc_irq = res->start; | |
136 | ||
137 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
138 | if (!res) | |
139 | return -ENODEV; | |
140 | ||
141 | rtc->rtc_base = devm_ioremap(dev, res->start, | |
45b4c85b | 142 | resource_size(res)); |
98a9bb5b HUK |
143 | |
144 | ret = devm_request_irq(dev, rtc->rtc_irq, gemini_rtc_interrupt, | |
145 | IRQF_SHARED, pdev->name, dev); | |
146 | if (unlikely(ret)) | |
147 | return ret; | |
148 | ||
149 | rtc->rtc_dev = rtc_device_register(pdev->name, dev, | |
150 | &gemini_rtc_ops, THIS_MODULE); | |
202cc98a | 151 | return PTR_ERR_OR_ZERO(rtc->rtc_dev); |
98a9bb5b HUK |
152 | } |
153 | ||
154 | static int gemini_rtc_remove(struct platform_device *pdev) | |
155 | { | |
156 | struct gemini_rtc *rtc = platform_get_drvdata(pdev); | |
157 | ||
158 | rtc_device_unregister(rtc->rtc_dev); | |
159 | platform_set_drvdata(pdev, NULL); | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | static struct platform_driver gemini_rtc_driver = { | |
165 | .driver = { | |
166 | .name = DRV_NAME, | |
98a9bb5b HUK |
167 | }, |
168 | .probe = gemini_rtc_probe, | |
169 | .remove = gemini_rtc_remove, | |
170 | }; | |
171 | ||
172 | module_platform_driver_probe(gemini_rtc_driver, gemini_rtc_probe); |