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1/*
2 * Faraday Technology FTRTC010 driver
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#include <linux/clk.h>
30
31#define DRV_NAME "rtc-ftrtc010"
32
33MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
34MODULE_DESCRIPTION("RTC driver for Gemini SoC");
35MODULE_LICENSE("GPL");
36MODULE_ALIAS("platform:" DRV_NAME);
37
38struct ftrtc010_rtc {
39 struct rtc_device *rtc_dev;
40 void __iomem *rtc_base;
41 int rtc_irq;
42 struct clk *pclk;
43 struct clk *extclk;
44};
45
46enum ftrtc010_rtc_offsets {
47 FTRTC010_RTC_SECOND = 0x00,
48 FTRTC010_RTC_MINUTE = 0x04,
49 FTRTC010_RTC_HOUR = 0x08,
50 FTRTC010_RTC_DAYS = 0x0C,
51 FTRTC010_RTC_ALARM_SECOND = 0x10,
52 FTRTC010_RTC_ALARM_MINUTE = 0x14,
53 FTRTC010_RTC_ALARM_HOUR = 0x18,
54 FTRTC010_RTC_RECORD = 0x1C,
55 FTRTC010_RTC_CR = 0x20,
56};
57
58static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)
59{
60 return IRQ_HANDLED;
61}
62
63/*
64 * Looks like the RTC in the Gemini SoC is (totaly) broken
65 * We can't read/write directly the time from RTC registers.
66 * We must do some "offset" calculation to get the real time
67 *
68 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
69 * the same thing, without the rtc-lib.c calls.
70 */
71
72static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)
73{
74 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
75
76 unsigned int days, hour, min, sec;
77 unsigned long offset, time;
78
79 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
80 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
81 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
82 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
83 offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);
84
85 time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
86
87 rtc_time_to_tm(time, tm);
88
89 return 0;
90}
91
92static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)
93{
94 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
95 unsigned int sec, min, hour, day;
96 unsigned long offset, time;
97
98 if (tm->tm_year >= 2148) /* EPOCH Year + 179 */
99 return -EINVAL;
100
101 rtc_tm_to_time(tm, &time);
102
103 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
104 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
105 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
106 day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
107
108 offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);
109
110 writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);
111 writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);
112
113 return 0;
114}
115
116static const struct rtc_class_ops ftrtc010_rtc_ops = {
117 .read_time = ftrtc010_rtc_read_time,
118 .set_time = ftrtc010_rtc_set_time,
119};
120
121static int ftrtc010_rtc_probe(struct platform_device *pdev)
122{
123 struct ftrtc010_rtc *rtc;
124 struct device *dev = &pdev->dev;
125 struct resource *res;
126 int ret;
127
128 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
129 if (unlikely(!rtc))
130 return -ENOMEM;
131 platform_set_drvdata(pdev, rtc);
132
133 rtc->pclk = devm_clk_get(dev, "PCLK");
134 if (IS_ERR(rtc->pclk)) {
135 dev_err(dev, "could not get PCLK\n");
136 } else {
137 ret = clk_prepare_enable(rtc->pclk);
138 if (ret) {
139 dev_err(dev, "failed to enable PCLK\n");
140 return ret;
141 }
142 }
143 rtc->extclk = devm_clk_get(dev, "EXTCLK");
144 if (IS_ERR(rtc->extclk)) {
145 dev_err(dev, "could not get EXTCLK\n");
146 } else {
147 ret = clk_prepare_enable(rtc->extclk);
148 if (ret) {
149 dev_err(dev, "failed to enable EXTCLK\n");
150 return ret;
151 }
152 }
153
154 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
155 if (!res)
156 return -ENODEV;
157
158 rtc->rtc_irq = res->start;
159
160 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
161 if (!res)
162 return -ENODEV;
163
164 rtc->rtc_base = devm_ioremap(dev, res->start,
165 resource_size(res));
166 if (!rtc->rtc_base)
167 return -ENOMEM;
168
169 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
170 IRQF_SHARED, pdev->name, dev);
171 if (unlikely(ret))
172 return ret;
173
174 rtc->rtc_dev = rtc_device_register(pdev->name, dev,
175 &ftrtc010_rtc_ops, THIS_MODULE);
176 return PTR_ERR_OR_ZERO(rtc->rtc_dev);
177}
178
179static int ftrtc010_rtc_remove(struct platform_device *pdev)
180{
181 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);
182
183 if (!IS_ERR(rtc->extclk))
184 clk_disable_unprepare(rtc->extclk);
185 if (!IS_ERR(rtc->pclk))
186 clk_disable_unprepare(rtc->pclk);
187 rtc_device_unregister(rtc->rtc_dev);
188
189 return 0;
190}
191
192static const struct of_device_id ftrtc010_rtc_dt_match[] = {
193 { .compatible = "cortina,gemini-rtc" },
194 { .compatible = "faraday,ftrtc010" },
195 { }
196};
197MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);
198
199static struct platform_driver ftrtc010_rtc_driver = {
200 .driver = {
201 .name = DRV_NAME,
202 .of_match_table = ftrtc010_rtc_dt_match,
203 },
204 .probe = ftrtc010_rtc_probe,
205 .remove = ftrtc010_rtc_remove,
206};
207
208module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);