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9#include <linux/clk.h>
10#include <linux/io.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/of_address.h>
14#include <linux/platform_device.h>
15#include <linux/rtc.h>
16#include <linux/spinlock.h>
17
18#define RTD_RTCSEC 0x00
19#define RTD_RTCMIN 0x04
20#define RTD_RTCHR 0x08
21#define RTD_RTCDATE1 0x0c
22#define RTD_RTCDATE2 0x10
23#define RTD_RTCACR 0x28
24#define RTD_RTCEN 0x2c
25#define RTD_RTCCR 0x30
26
27#define RTD_RTCSEC_RTCSEC_MASK 0x7f
28
29#define RTD_RTCMIN_RTCMIN_MASK 0x3f
30
31#define RTD_RTCHR_RTCHR_MASK 0x1f
32
33#define RTD_RTCDATE1_RTCDATE1_MASK 0xff
34
35#define RTD_RTCDATE2_RTCDATE2_MASK 0x7f
36
37#define RTD_RTCACR_RTCPWR BIT(7)
38
39#define RTD_RTCEN_RTCEN_MASK 0xff
40
41#define RTD_RTCCR_RTCRST BIT(6)
42
43struct rtd119x_rtc {
44 void __iomem *base;
45 struct clk *clk;
46 struct rtc_device *rtcdev;
47 unsigned int base_year;
48};
49
50static inline int rtd119x_rtc_days_in_year(int year)
51{
52 return 365 + (is_leap_year(year) ? 1 : 0);
53}
54
55static void rtd119x_rtc_reset(struct device *dev)
56{
57 struct rtd119x_rtc *data = dev_get_drvdata(dev);
58 u32 val;
59
60 val = readl_relaxed(data->base + RTD_RTCCR);
61 val |= RTD_RTCCR_RTCRST;
62 writel_relaxed(val, data->base + RTD_RTCCR);
63
64 val &= ~RTD_RTCCR_RTCRST;
65 writel(val, data->base + RTD_RTCCR);
66}
67
68static void rtd119x_rtc_set_enabled(struct device *dev, bool enable)
69{
70 struct rtd119x_rtc *data = dev_get_drvdata(dev);
71 u32 val;
72
73 val = readl_relaxed(data->base + RTD_RTCEN);
74 if (enable) {
75 if ((val & RTD_RTCEN_RTCEN_MASK) == 0x5a)
76 return;
77 writel_relaxed(0x5a, data->base + RTD_RTCEN);
78 } else {
79 writel_relaxed(0, data->base + RTD_RTCEN);
80 }
81}
82
83static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm)
84{
85 struct rtd119x_rtc *data = dev_get_drvdata(dev);
86 s32 day;
87 u32 sec;
88 unsigned int year;
89 int tries = 0;
90
91 while (true) {
92 tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
93 tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK;
94 tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK;
95 day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK;
96 day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8;
97 sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
98 tries++;
99
100 if (sec == tm->tm_sec)
101 break;
102
103 if (tries >= 3)
104 return -EINVAL;
105 }
106 if (tries > 1)
107 dev_dbg(dev, "%s: needed %i tries\n", __func__, tries);
108
109 year = data->base_year;
110 while (day >= rtd119x_rtc_days_in_year(year)) {
111 day -= rtd119x_rtc_days_in_year(year);
112 year++;
113 }
114 tm->tm_year = year - 1900;
115 tm->tm_yday = day;
116
117 tm->tm_mon = 0;
118 while (day >= rtc_month_days(tm->tm_mon, year)) {
119 day -= rtc_month_days(tm->tm_mon, year);
120 tm->tm_mon++;
121 }
122 tm->tm_mday = day + 1;
123
124 return 0;
125}
126
127static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm)
128{
129 struct rtd119x_rtc *data = dev_get_drvdata(dev);
130 unsigned int day;
131 int i;
132
133 if (1900 + tm->tm_year < data->base_year)
134 return -EINVAL;
135
136 day = 0;
137 for (i = data->base_year; i < 1900 + tm->tm_year; i++)
138 day += rtd119x_rtc_days_in_year(i);
139
140 day += tm->tm_yday;
141 if (day > 0x7fff)
142 return -EINVAL;
143
144 rtd119x_rtc_set_enabled(dev, false);
145
146 writel_relaxed((tm->tm_sec << 1) & RTD_RTCSEC_RTCSEC_MASK, data->base + RTD_RTCSEC);
147 writel_relaxed(tm->tm_min & RTD_RTCMIN_RTCMIN_MASK, data->base + RTD_RTCMIN);
148 writel_relaxed(tm->tm_hour & RTD_RTCHR_RTCHR_MASK, data->base + RTD_RTCHR);
149 writel_relaxed(day & RTD_RTCDATE1_RTCDATE1_MASK, data->base + RTD_RTCDATE1);
150 writel_relaxed((day >> 8) & RTD_RTCDATE2_RTCDATE2_MASK, data->base + RTD_RTCDATE2);
151
152 rtd119x_rtc_set_enabled(dev, true);
153
154 return 0;
155}
156
157static const struct rtc_class_ops rtd119x_rtc_ops = {
158 .read_time = rtd119x_rtc_read_time,
159 .set_time = rtd119x_rtc_set_time,
160};
161
162static const struct of_device_id rtd119x_rtc_dt_ids[] = {
163 { .compatible = "realtek,rtd1295-rtc" },
164 { }
165};
166
167static int rtd119x_rtc_probe(struct platform_device *pdev)
168{
169 struct rtd119x_rtc *data;
170 struct resource *res;
171 u32 val;
172 int ret;
173
174 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
175 if (!data)
176 return -ENOMEM;
177
178 platform_set_drvdata(pdev, data);
179 data->base_year = 2014;
180
181 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
182 data->base = devm_ioremap_resource(&pdev->dev, res);
183 if (IS_ERR(data->base))
184 return PTR_ERR(data->base);
185
186 data->clk = of_clk_get(pdev->dev.of_node, 0);
187 if (IS_ERR(data->clk))
188 return PTR_ERR(data->clk);
189
190 ret = clk_prepare_enable(data->clk);
191 if (ret) {
192 clk_put(data->clk);
193 return ret;
194 }
195
196 val = readl_relaxed(data->base + RTD_RTCACR);
197 if (!(val & RTD_RTCACR_RTCPWR)) {
198 writel_relaxed(RTD_RTCACR_RTCPWR, data->base + RTD_RTCACR);
199
200 rtd119x_rtc_reset(&pdev->dev);
201
202 writel_relaxed(0, data->base + RTD_RTCMIN);
203 writel_relaxed(0, data->base + RTD_RTCHR);
204 writel_relaxed(0, data->base + RTD_RTCDATE1);
205 writel_relaxed(0, data->base + RTD_RTCDATE2);
206 }
207
208 rtd119x_rtc_set_enabled(&pdev->dev, true);
209
210 data->rtcdev = devm_rtc_device_register(&pdev->dev, "rtc",
211 &rtd119x_rtc_ops, THIS_MODULE);
212 if (IS_ERR(data->rtcdev)) {
213 dev_err(&pdev->dev, "failed to register rtc device");
214 clk_disable_unprepare(data->clk);
215 clk_put(data->clk);
216 return PTR_ERR(data->rtcdev);
217 }
218
219 return 0;
220}
221
222static int rtd119x_rtc_remove(struct platform_device *pdev)
223{
224 struct rtd119x_rtc *data = platform_get_drvdata(pdev);
225
226 rtd119x_rtc_set_enabled(&pdev->dev, false);
227
228 clk_disable_unprepare(data->clk);
229 clk_put(data->clk);
230
231 return 0;
232}
233
234static struct platform_driver rtd119x_rtc_driver = {
235 .probe = rtd119x_rtc_probe,
236 .remove = rtd119x_rtc_remove,
237 .driver = {
238 .name = "rtd1295-rtc",
239 .of_match_table = rtd119x_rtc_dt_ids,
240 },
241};
242builtin_platform_driver(rtd119x_rtc_driver);
243
