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/mod_devicetable.h>
30 #include <linux/clk.h>
31
32 #define DRV_NAME "rtc-ftrtc010"
33
34 MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
35 MODULE_DESCRIPTION("RTC driver for Gemini SoC");
36 MODULE_LICENSE("GPL");
37 MODULE_ALIAS("platform:" DRV_NAME);
38
39 struct ftrtc010_rtc {
40 struct rtc_device *rtc_dev;
41 void __iomem *rtc_base;
42 int rtc_irq;
43 struct clk *pclk;
44 struct clk *extclk;
45 };
46
47 enum ftrtc010_rtc_offsets {
48 FTRTC010_RTC_SECOND = 0x00,
49 FTRTC010_RTC_MINUTE = 0x04,
50 FTRTC010_RTC_HOUR = 0x08,
51 FTRTC010_RTC_DAYS = 0x0C,
52 FTRTC010_RTC_ALARM_SECOND = 0x10,
53 FTRTC010_RTC_ALARM_MINUTE = 0x14,
54 FTRTC010_RTC_ALARM_HOUR = 0x18,
55 FTRTC010_RTC_RECORD = 0x1C,
56 FTRTC010_RTC_CR = 0x20,
57 };
58
ftrtc010_rtc_interrupt(int irq,void * dev)59 static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)
60 {
61 return IRQ_HANDLED;
62 }
63
64 /*
65 * Looks like the RTC in the Gemini SoC is (totaly) broken
66 * We can't read/write directly the time from RTC registers.
67 * We must do some "offset" calculation to get the real time
68 *
69 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
70 * the same thing, without the rtc-lib.c calls.
71 */
72
ftrtc010_rtc_read_time(struct device * dev,struct rtc_time * tm)73 static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)
74 {
75 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
76
77 u32 days, hour, min, sec, offset;
78 timeu64_t time;
79
80 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
81 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
82 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
83 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
84 offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);
85
86 time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
87
88 rtc_time64_to_tm(time, tm);
89
90 return 0;
91 }
92
ftrtc010_rtc_set_time(struct device * dev,struct rtc_time * tm)93 static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)
94 {
95 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
96 u32 sec, min, hour, day, offset;
97 timeu64_t time;
98
99 time = rtc_tm_to_time64(tm);
100
101 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
102 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
103 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
104 day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
105
106 offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);
107
108 writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);
109 writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);
110
111 return 0;
112 }
113
114 static const struct rtc_class_ops ftrtc010_rtc_ops = {
115 .read_time = ftrtc010_rtc_read_time,
116 .set_time = ftrtc010_rtc_set_time,
117 };
118
ftrtc010_rtc_probe(struct platform_device * pdev)119 static int ftrtc010_rtc_probe(struct platform_device *pdev)
120 {
121 u32 days, hour, min, sec;
122 struct ftrtc010_rtc *rtc;
123 struct device *dev = &pdev->dev;
124 struct resource *res;
125 int ret;
126
127 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
128 if (unlikely(!rtc))
129 return -ENOMEM;
130 platform_set_drvdata(pdev, rtc);
131
132 rtc->pclk = devm_clk_get(dev, "PCLK");
133 if (IS_ERR(rtc->pclk)) {
134 dev_err(dev, "could not get PCLK\n");
135 } else {
136 ret = clk_prepare_enable(rtc->pclk);
137 if (ret) {
138 dev_err(dev, "failed to enable PCLK\n");
139 return ret;
140 }
141 }
142 rtc->extclk = devm_clk_get(dev, "EXTCLK");
143 if (IS_ERR(rtc->extclk)) {
144 dev_err(dev, "could not get EXTCLK\n");
145 } else {
146 ret = clk_prepare_enable(rtc->extclk);
147 if (ret) {
148 dev_err(dev, "failed to enable EXTCLK\n");
149 return ret;
150 }
151 }
152
153 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
154 if (!res)
155 return -ENODEV;
156
157 rtc->rtc_irq = res->start;
158
159 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
160 if (!res)
161 return -ENODEV;
162
163 rtc->rtc_base = devm_ioremap(dev, res->start,
164 resource_size(res));
165 if (!rtc->rtc_base)
166 return -ENOMEM;
167
168 rtc->rtc_dev = devm_rtc_allocate_device(dev);
169 if (IS_ERR(rtc->rtc_dev))
170 return PTR_ERR(rtc->rtc_dev);
171
172 rtc->rtc_dev->ops = &ftrtc010_rtc_ops;
173
174 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
175 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
176 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
177 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
178
179 rtc->rtc_dev->range_min = (u64)days * 86400 + hour * 3600 +
180 min * 60 + sec;
181 rtc->rtc_dev->range_max = U32_MAX + rtc->rtc_dev->range_min;
182
183 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
184 IRQF_SHARED, pdev->name, dev);
185 if (unlikely(ret))
186 return ret;
187
188 return rtc_register_device(rtc->rtc_dev);
189 }
190
ftrtc010_rtc_remove(struct platform_device * pdev)191 static int ftrtc010_rtc_remove(struct platform_device *pdev)
192 {
193 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);
194
195 if (!IS_ERR(rtc->extclk))
196 clk_disable_unprepare(rtc->extclk);
197 if (!IS_ERR(rtc->pclk))
198 clk_disable_unprepare(rtc->pclk);
199
200 return 0;
201 }
202
203 static const struct of_device_id ftrtc010_rtc_dt_match[] = {
204 { .compatible = "cortina,gemini-rtc" },
205 { .compatible = "faraday,ftrtc010" },
206 { }
207 };
208 MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);
209
210 static struct platform_driver ftrtc010_rtc_driver = {
211 .driver = {
212 .name = DRV_NAME,
213 .of_match_table = ftrtc010_rtc_dt_match,
214 },
215 .probe = ftrtc010_rtc_probe,
216 .remove = ftrtc010_rtc_remove,
217 };
218
219 module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);
220