1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Realtek RTD129x RTC |
4 | * |
5 | * Copyright (c) 2017 Andreas Färber |
6 | */ |
7 | |
8 | #include <linux/clk.h> |
9 | #include <linux/io.h> |
10 | #include <linux/module.h> |
11 | #include <linux/of.h> |
12 | #include <linux/of_address.h> |
13 | #include <linux/platform_device.h> |
14 | #include <linux/rtc.h> |
15 | #include <linux/spinlock.h> |
16 | |
17 | #define RTD_RTCSEC 0x00 |
18 | #define RTD_RTCMIN 0x04 |
19 | #define RTD_RTCHR 0x08 |
20 | #define RTD_RTCDATE1 0x0c |
21 | #define RTD_RTCDATE2 0x10 |
22 | #define RTD_RTCACR 0x28 |
23 | #define RTD_RTCEN 0x2c |
24 | #define RTD_RTCCR 0x30 |
25 | |
26 | #define RTD_RTCSEC_RTCSEC_MASK 0x7f |
27 | |
28 | #define RTD_RTCMIN_RTCMIN_MASK 0x3f |
29 | |
30 | #define RTD_RTCHR_RTCHR_MASK 0x1f |
31 | |
32 | #define RTD_RTCDATE1_RTCDATE1_MASK 0xff |
33 | |
34 | #define RTD_RTCDATE2_RTCDATE2_MASK 0x7f |
35 | |
36 | #define RTD_RTCACR_RTCPWR BIT(7) |
37 | |
38 | #define RTD_RTCEN_RTCEN_MASK 0xff |
39 | |
40 | #define RTD_RTCCR_RTCRST BIT(6) |
41 | |
42 | struct rtd119x_rtc { |
43 | void __iomem *base; |
44 | struct clk *clk; |
45 | struct rtc_device *rtcdev; |
46 | unsigned int base_year; |
47 | }; |
48 | |
49 | static inline int rtd119x_rtc_days_in_year(int year) |
50 | { |
51 | return 365 + (is_leap_year(year) ? 1 : 0); |
52 | } |
53 | |
54 | static void rtd119x_rtc_reset(struct device *dev) |
55 | { |
56 | struct rtd119x_rtc *data = dev_get_drvdata(dev); |
57 | u32 val; |
58 | |
59 | val = readl_relaxed(data->base + RTD_RTCCR); |
60 | val |= RTD_RTCCR_RTCRST; |
61 | writel_relaxed(val, data->base + RTD_RTCCR); |
62 | |
63 | val &= ~RTD_RTCCR_RTCRST; |
64 | writel(val, addr: data->base + RTD_RTCCR); |
65 | } |
66 | |
67 | static void rtd119x_rtc_set_enabled(struct device *dev, bool enable) |
68 | { |
69 | struct rtd119x_rtc *data = dev_get_drvdata(dev); |
70 | u32 val; |
71 | |
72 | val = readl_relaxed(data->base + RTD_RTCEN); |
73 | if (enable) { |
74 | if ((val & RTD_RTCEN_RTCEN_MASK) == 0x5a) |
75 | return; |
76 | writel_relaxed(0x5a, data->base + RTD_RTCEN); |
77 | } else { |
78 | writel_relaxed(0, data->base + RTD_RTCEN); |
79 | } |
80 | } |
81 | |
82 | static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm) |
83 | { |
84 | struct rtd119x_rtc *data = dev_get_drvdata(dev); |
85 | s32 day; |
86 | u32 sec; |
87 | unsigned int year; |
88 | int tries = 0; |
89 | |
90 | while (true) { |
91 | tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; |
92 | tm->tm_min = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK; |
93 | tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK; |
94 | day = readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK; |
95 | day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8; |
96 | sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1; |
97 | tries++; |
98 | |
99 | if (sec == tm->tm_sec) |
100 | break; |
101 | |
102 | if (tries >= 3) |
103 | return -EINVAL; |
104 | } |
105 | if (tries > 1) |
106 | dev_dbg(dev, "%s: needed %i tries\n" , __func__, tries); |
107 | |
108 | year = data->base_year; |
109 | while (day >= rtd119x_rtc_days_in_year(year)) { |
110 | day -= rtd119x_rtc_days_in_year(year); |
111 | year++; |
112 | } |
113 | tm->tm_year = year - 1900; |
114 | tm->tm_yday = day; |
115 | |
116 | tm->tm_mon = 0; |
117 | while (day >= rtc_month_days(month: tm->tm_mon, year)) { |
118 | day -= rtc_month_days(month: tm->tm_mon, year); |
119 | tm->tm_mon++; |
120 | } |
121 | tm->tm_mday = day + 1; |
122 | |
123 | return 0; |
124 | } |
125 | |
126 | static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm) |
127 | { |
128 | struct rtd119x_rtc *data = dev_get_drvdata(dev); |
129 | unsigned int day; |
130 | int i; |
131 | |
132 | if (1900 + tm->tm_year < data->base_year) |
133 | return -EINVAL; |
134 | |
135 | day = 0; |
136 | for (i = data->base_year; i < 1900 + tm->tm_year; i++) |
137 | day += rtd119x_rtc_days_in_year(year: i); |
138 | |
139 | day += tm->tm_yday; |
140 | if (day > 0x7fff) |
141 | return -EINVAL; |
142 | |
143 | rtd119x_rtc_set_enabled(dev, enable: false); |
144 | |
145 | writel_relaxed((tm->tm_sec << 1) & RTD_RTCSEC_RTCSEC_MASK, data->base + RTD_RTCSEC); |
146 | writel_relaxed(tm->tm_min & RTD_RTCMIN_RTCMIN_MASK, data->base + RTD_RTCMIN); |
147 | writel_relaxed(tm->tm_hour & RTD_RTCHR_RTCHR_MASK, data->base + RTD_RTCHR); |
148 | writel_relaxed(day & RTD_RTCDATE1_RTCDATE1_MASK, data->base + RTD_RTCDATE1); |
149 | writel_relaxed((day >> 8) & RTD_RTCDATE2_RTCDATE2_MASK, data->base + RTD_RTCDATE2); |
150 | |
151 | rtd119x_rtc_set_enabled(dev, enable: true); |
152 | |
153 | return 0; |
154 | } |
155 | |
156 | static const struct rtc_class_ops rtd119x_rtc_ops = { |
157 | .read_time = rtd119x_rtc_read_time, |
158 | .set_time = rtd119x_rtc_set_time, |
159 | }; |
160 | |
161 | static const struct of_device_id rtd119x_rtc_dt_ids[] = { |
162 | { .compatible = "realtek,rtd1295-rtc" }, |
163 | { } |
164 | }; |
165 | |
166 | static int rtd119x_rtc_probe(struct platform_device *pdev) |
167 | { |
168 | struct rtd119x_rtc *data; |
169 | u32 val; |
170 | int ret; |
171 | |
172 | data = devm_kzalloc(dev: &pdev->dev, size: sizeof(*data), GFP_KERNEL); |
173 | if (!data) |
174 | return -ENOMEM; |
175 | |
176 | platform_set_drvdata(pdev, data); |
177 | data->base_year = 2014; |
178 | |
179 | data->base = devm_platform_ioremap_resource(pdev, index: 0); |
180 | if (IS_ERR(ptr: data->base)) |
181 | return PTR_ERR(ptr: data->base); |
182 | |
183 | data->clk = of_clk_get(np: pdev->dev.of_node, index: 0); |
184 | if (IS_ERR(ptr: data->clk)) |
185 | return PTR_ERR(ptr: data->clk); |
186 | |
187 | ret = clk_prepare_enable(clk: data->clk); |
188 | if (ret) { |
189 | clk_put(clk: data->clk); |
190 | return ret; |
191 | } |
192 | |
193 | val = readl_relaxed(data->base + RTD_RTCACR); |
194 | if (!(val & RTD_RTCACR_RTCPWR)) { |
195 | writel_relaxed(RTD_RTCACR_RTCPWR, data->base + RTD_RTCACR); |
196 | |
197 | rtd119x_rtc_reset(dev: &pdev->dev); |
198 | |
199 | writel_relaxed(0, data->base + RTD_RTCMIN); |
200 | writel_relaxed(0, data->base + RTD_RTCHR); |
201 | writel_relaxed(0, data->base + RTD_RTCDATE1); |
202 | writel_relaxed(0, data->base + RTD_RTCDATE2); |
203 | } |
204 | |
205 | rtd119x_rtc_set_enabled(dev: &pdev->dev, enable: true); |
206 | |
207 | data->rtcdev = devm_rtc_device_register(dev: &pdev->dev, name: "rtc" , |
208 | ops: &rtd119x_rtc_ops, THIS_MODULE); |
209 | if (IS_ERR(ptr: data->rtcdev)) { |
210 | dev_err(&pdev->dev, "failed to register rtc device" ); |
211 | clk_disable_unprepare(clk: data->clk); |
212 | clk_put(clk: data->clk); |
213 | return PTR_ERR(ptr: data->rtcdev); |
214 | } |
215 | |
216 | return 0; |
217 | } |
218 | |
219 | static void rtd119x_rtc_remove(struct platform_device *pdev) |
220 | { |
221 | struct rtd119x_rtc *data = platform_get_drvdata(pdev); |
222 | |
223 | rtd119x_rtc_set_enabled(dev: &pdev->dev, enable: false); |
224 | |
225 | clk_disable_unprepare(clk: data->clk); |
226 | clk_put(clk: data->clk); |
227 | } |
228 | |
229 | static struct platform_driver rtd119x_rtc_driver = { |
230 | .probe = rtd119x_rtc_probe, |
231 | .remove_new = rtd119x_rtc_remove, |
232 | .driver = { |
233 | .name = "rtd1295-rtc" , |
234 | .of_match_table = rtd119x_rtc_dt_ids, |
235 | }, |
236 | }; |
237 | builtin_platform_driver(rtd119x_rtc_driver); |
238 | |