1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Oki MSM6242 RTC Driver |
4 | * |
5 | * Copyright 2009 Geert Uytterhoeven |
6 | * |
7 | * Based on the A2000 TOD code in arch/m68k/amiga/config.c |
8 | * Copyright (C) 1993 Hamish Macdonald |
9 | */ |
10 | |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | |
13 | #include <linux/delay.h> |
14 | #include <linux/io.h> |
15 | #include <linux/kernel.h> |
16 | #include <linux/module.h> |
17 | #include <linux/platform_device.h> |
18 | #include <linux/rtc.h> |
19 | #include <linux/slab.h> |
20 | |
21 | |
22 | enum { |
23 | MSM6242_SECOND1 = 0x0, /* 1-second digit register */ |
24 | MSM6242_SECOND10 = 0x1, /* 10-second digit register */ |
25 | MSM6242_MINUTE1 = 0x2, /* 1-minute digit register */ |
26 | MSM6242_MINUTE10 = 0x3, /* 10-minute digit register */ |
27 | MSM6242_HOUR1 = 0x4, /* 1-hour digit register */ |
28 | MSM6242_HOUR10 = 0x5, /* PM/AM, 10-hour digit register */ |
29 | MSM6242_DAY1 = 0x6, /* 1-day digit register */ |
30 | MSM6242_DAY10 = 0x7, /* 10-day digit register */ |
31 | MSM6242_MONTH1 = 0x8, /* 1-month digit register */ |
32 | MSM6242_MONTH10 = 0x9, /* 10-month digit register */ |
33 | MSM6242_YEAR1 = 0xa, /* 1-year digit register */ |
34 | MSM6242_YEAR10 = 0xb, /* 10-year digit register */ |
35 | MSM6242_WEEK = 0xc, /* Week register */ |
36 | MSM6242_CD = 0xd, /* Control Register D */ |
37 | MSM6242_CE = 0xe, /* Control Register E */ |
38 | MSM6242_CF = 0xf, /* Control Register F */ |
39 | }; |
40 | |
41 | #define MSM6242_HOUR10_AM (0 << 2) |
42 | #define MSM6242_HOUR10_PM (1 << 2) |
43 | #define MSM6242_HOUR10_HR_MASK (3 << 0) |
44 | |
45 | #define MSM6242_WEEK_SUNDAY 0 |
46 | #define MSM6242_WEEK_MONDAY 1 |
47 | #define MSM6242_WEEK_TUESDAY 2 |
48 | #define MSM6242_WEEK_WEDNESDAY 3 |
49 | #define MSM6242_WEEK_THURSDAY 4 |
50 | #define MSM6242_WEEK_FRIDAY 5 |
51 | #define MSM6242_WEEK_SATURDAY 6 |
52 | |
53 | #define MSM6242_CD_30_S_ADJ (1 << 3) /* 30-second adjustment */ |
54 | #define MSM6242_CD_IRQ_FLAG (1 << 2) |
55 | #define MSM6242_CD_BUSY (1 << 1) |
56 | #define MSM6242_CD_HOLD (1 << 0) |
57 | |
58 | #define MSM6242_CE_T_MASK (3 << 2) |
59 | #define MSM6242_CE_T_64HZ (0 << 2) /* period 1/64 second */ |
60 | #define MSM6242_CE_T_1HZ (1 << 2) /* period 1 second */ |
61 | #define MSM6242_CE_T_1MINUTE (2 << 2) /* period 1 minute */ |
62 | #define MSM6242_CE_T_1HOUR (3 << 2) /* period 1 hour */ |
63 | |
64 | #define MSM6242_CE_ITRPT_STND (1 << 1) |
65 | #define MSM6242_CE_MASK (1 << 0) /* STD.P output control */ |
66 | |
67 | #define MSM6242_CF_TEST (1 << 3) |
68 | #define MSM6242_CF_12H (0 << 2) |
69 | #define MSM6242_CF_24H (1 << 2) |
70 | #define MSM6242_CF_STOP (1 << 1) |
71 | #define MSM6242_CF_REST (1 << 0) /* reset */ |
72 | |
73 | |
74 | struct msm6242_priv { |
75 | u32 __iomem *regs; |
76 | struct rtc_device *rtc; |
77 | }; |
78 | |
79 | static inline unsigned int msm6242_read(struct msm6242_priv *priv, |
80 | unsigned int reg) |
81 | { |
82 | return __raw_readl(addr: &priv->regs[reg]) & 0xf; |
83 | } |
84 | |
85 | static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val, |
86 | unsigned int reg) |
87 | { |
88 | __raw_writel(val, addr: &priv->regs[reg]); |
89 | } |
90 | |
91 | static void msm6242_lock(struct msm6242_priv *priv) |
92 | { |
93 | int cnt = 5; |
94 | |
95 | msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, reg: MSM6242_CD); |
96 | |
97 | while ((msm6242_read(priv, reg: MSM6242_CD) & MSM6242_CD_BUSY) && cnt) { |
98 | msm6242_write(priv, MSM6242_CD_IRQ_FLAG, reg: MSM6242_CD); |
99 | udelay(70); |
100 | msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, reg: MSM6242_CD); |
101 | cnt--; |
102 | } |
103 | |
104 | if (!cnt) |
105 | pr_warn("timed out waiting for RTC (0x%x)\n" , |
106 | msm6242_read(priv, MSM6242_CD)); |
107 | } |
108 | |
109 | static void msm6242_unlock(struct msm6242_priv *priv) |
110 | { |
111 | msm6242_write(priv, MSM6242_CD_IRQ_FLAG, reg: MSM6242_CD); |
112 | } |
113 | |
114 | static int msm6242_read_time(struct device *dev, struct rtc_time *tm) |
115 | { |
116 | struct msm6242_priv *priv = dev_get_drvdata(dev); |
117 | |
118 | msm6242_lock(priv); |
119 | |
120 | tm->tm_sec = msm6242_read(priv, reg: MSM6242_SECOND10) * 10 + |
121 | msm6242_read(priv, reg: MSM6242_SECOND1); |
122 | tm->tm_min = msm6242_read(priv, reg: MSM6242_MINUTE10) * 10 + |
123 | msm6242_read(priv, reg: MSM6242_MINUTE1); |
124 | tm->tm_hour = (msm6242_read(priv, reg: MSM6242_HOUR10) & |
125 | MSM6242_HOUR10_HR_MASK) * 10 + |
126 | msm6242_read(priv, reg: MSM6242_HOUR1); |
127 | tm->tm_mday = msm6242_read(priv, reg: MSM6242_DAY10) * 10 + |
128 | msm6242_read(priv, reg: MSM6242_DAY1); |
129 | tm->tm_wday = msm6242_read(priv, reg: MSM6242_WEEK); |
130 | tm->tm_mon = msm6242_read(priv, reg: MSM6242_MONTH10) * 10 + |
131 | msm6242_read(priv, reg: MSM6242_MONTH1) - 1; |
132 | tm->tm_year = msm6242_read(priv, reg: MSM6242_YEAR10) * 10 + |
133 | msm6242_read(priv, reg: MSM6242_YEAR1); |
134 | if (tm->tm_year <= 69) |
135 | tm->tm_year += 100; |
136 | |
137 | if (!(msm6242_read(priv, reg: MSM6242_CF) & MSM6242_CF_24H)) { |
138 | unsigned int pm = msm6242_read(priv, reg: MSM6242_HOUR10) & |
139 | MSM6242_HOUR10_PM; |
140 | if (!pm && tm->tm_hour == 12) |
141 | tm->tm_hour = 0; |
142 | else if (pm && tm->tm_hour != 12) |
143 | tm->tm_hour += 12; |
144 | } |
145 | |
146 | msm6242_unlock(priv); |
147 | |
148 | return 0; |
149 | } |
150 | |
151 | static int msm6242_set_time(struct device *dev, struct rtc_time *tm) |
152 | { |
153 | struct msm6242_priv *priv = dev_get_drvdata(dev); |
154 | |
155 | msm6242_lock(priv); |
156 | |
157 | msm6242_write(priv, val: tm->tm_sec / 10, reg: MSM6242_SECOND10); |
158 | msm6242_write(priv, val: tm->tm_sec % 10, reg: MSM6242_SECOND1); |
159 | msm6242_write(priv, val: tm->tm_min / 10, reg: MSM6242_MINUTE10); |
160 | msm6242_write(priv, val: tm->tm_min % 10, reg: MSM6242_MINUTE1); |
161 | if (msm6242_read(priv, reg: MSM6242_CF) & MSM6242_CF_24H) |
162 | msm6242_write(priv, val: tm->tm_hour / 10, reg: MSM6242_HOUR10); |
163 | else if (tm->tm_hour >= 12) |
164 | msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10, |
165 | reg: MSM6242_HOUR10); |
166 | else |
167 | msm6242_write(priv, val: tm->tm_hour / 10, reg: MSM6242_HOUR10); |
168 | msm6242_write(priv, val: tm->tm_hour % 10, reg: MSM6242_HOUR1); |
169 | msm6242_write(priv, val: tm->tm_mday / 10, reg: MSM6242_DAY10); |
170 | msm6242_write(priv, val: tm->tm_mday % 10, reg: MSM6242_DAY1); |
171 | if (tm->tm_wday != -1) |
172 | msm6242_write(priv, val: tm->tm_wday, reg: MSM6242_WEEK); |
173 | msm6242_write(priv, val: (tm->tm_mon + 1) / 10, reg: MSM6242_MONTH10); |
174 | msm6242_write(priv, val: (tm->tm_mon + 1) % 10, reg: MSM6242_MONTH1); |
175 | if (tm->tm_year >= 100) |
176 | tm->tm_year -= 100; |
177 | msm6242_write(priv, val: tm->tm_year / 10, reg: MSM6242_YEAR10); |
178 | msm6242_write(priv, val: tm->tm_year % 10, reg: MSM6242_YEAR1); |
179 | |
180 | msm6242_unlock(priv); |
181 | return 0; |
182 | } |
183 | |
184 | static const struct rtc_class_ops msm6242_rtc_ops = { |
185 | .read_time = msm6242_read_time, |
186 | .set_time = msm6242_set_time, |
187 | }; |
188 | |
189 | static int __init msm6242_rtc_probe(struct platform_device *pdev) |
190 | { |
191 | struct resource *res; |
192 | struct msm6242_priv *priv; |
193 | struct rtc_device *rtc; |
194 | |
195 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
196 | if (!res) |
197 | return -ENODEV; |
198 | |
199 | priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL); |
200 | if (!priv) |
201 | return -ENOMEM; |
202 | |
203 | priv->regs = devm_ioremap(dev: &pdev->dev, offset: res->start, size: resource_size(res)); |
204 | if (!priv->regs) |
205 | return -ENOMEM; |
206 | platform_set_drvdata(pdev, data: priv); |
207 | |
208 | rtc = devm_rtc_device_register(dev: &pdev->dev, name: "rtc-msm6242" , |
209 | ops: &msm6242_rtc_ops, THIS_MODULE); |
210 | if (IS_ERR(ptr: rtc)) |
211 | return PTR_ERR(ptr: rtc); |
212 | |
213 | priv->rtc = rtc; |
214 | return 0; |
215 | } |
216 | |
217 | static struct platform_driver msm6242_rtc_driver = { |
218 | .driver = { |
219 | .name = "rtc-msm6242" , |
220 | }, |
221 | }; |
222 | |
223 | module_platform_driver_probe(msm6242_rtc_driver, msm6242_rtc_probe); |
224 | |
225 | MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>" ); |
226 | MODULE_LICENSE("GPL" ); |
227 | MODULE_DESCRIPTION("Oki MSM6242 RTC driver" ); |
228 | MODULE_ALIAS("platform:rtc-msm6242" ); |
229 | |