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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
22enum {
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
74struct msm6242_priv {
75 u32 __iomem *regs;
76 struct rtc_device *rtc;
77};
78
79static inline unsigned int msm6242_read(struct msm6242_priv *priv,
80 unsigned int reg)
81{
82 return __raw_readl(&priv->regs[reg]) & 0xf;
83}
84
85static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
86 unsigned int reg)
87{
88 __raw_writel(val, &priv->regs[reg]);
89}
90
91static void msm6242_lock(struct msm6242_priv *priv)
92{
93 int cnt = 5;
94
95 msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, MSM6242_CD);
96
97 while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
98 msm6242_write(priv, MSM6242_CD_IRQ_FLAG, MSM6242_CD);
99 udelay(70);
100 msm6242_write(priv, MSM6242_CD_HOLD|MSM6242_CD_IRQ_FLAG, 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
109static void msm6242_unlock(struct msm6242_priv *priv)
110{
111 msm6242_write(priv, MSM6242_CD_IRQ_FLAG, MSM6242_CD);
112}
113
114static 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, MSM6242_SECOND10) * 10 +
121 msm6242_read(priv, MSM6242_SECOND1);
122 tm->tm_min = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
123 msm6242_read(priv, MSM6242_MINUTE1);
124 tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10) &
125 MSM6242_HOUR10_HR_MASK) * 10 +
126 msm6242_read(priv, MSM6242_HOUR1);
127 tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
128 msm6242_read(priv, MSM6242_DAY1);
129 tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
130 tm->tm_mon = msm6242_read(priv, MSM6242_MONTH10) * 10 +
131 msm6242_read(priv, MSM6242_MONTH1) - 1;
132 tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
133 msm6242_read(priv, MSM6242_YEAR1);
134 if (tm->tm_year <= 69)
135 tm->tm_year += 100;
136
137 if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
138 unsigned int pm = msm6242_read(priv, 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
151static 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, tm->tm_sec / 10, MSM6242_SECOND10);
158 msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
159 msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
160 msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
161 if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
162 msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
163 else if (tm->tm_hour >= 12)
164 msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
165 MSM6242_HOUR10);
166 else
167 msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
168 msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
169 msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
170 msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
171 if (tm->tm_wday != -1)
172 msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
173 msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
174 msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
175 if (tm->tm_year >= 100)
176 tm->tm_year -= 100;
177 msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
178 msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
179
180 msm6242_unlock(priv);
181 return 0;
182}
183
184static const struct rtc_class_ops msm6242_rtc_ops = {
185 .read_time = msm6242_read_time,
186 .set_time = msm6242_set_time,
187};
188
189static 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(&pdev->dev, sizeof(*priv), GFP_KERNEL);
200 if (!priv)
201 return -ENOMEM;
202
203 priv->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
204 if (!priv->regs)
205 return -ENOMEM;
206 platform_set_drvdata(pdev, priv);
207
208 rtc = devm_rtc_device_register(&pdev->dev, "rtc-msm6242",
209 &msm6242_rtc_ops, THIS_MODULE);
210 if (IS_ERR(rtc))
211 return PTR_ERR(rtc);
212
213 priv->rtc = rtc;
214 return 0;
215}
216
217static struct platform_driver msm6242_rtc_driver = {
218 .driver = {
219 .name = "rtc-msm6242",
220 },
221};
222
223module_platform_driver_probe(msm6242_rtc_driver, msm6242_rtc_probe);
224
225MODULE_AUTHOR("Geert Uytterhoeven <[email protected]>");
226MODULE_LICENSE("GPL");
227MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
228MODULE_ALIAS("platform:rtc-msm6242");