xref: /linux/drivers/rtc/rtc-msm6242.c (revision c95baf12f5077419db01313ab61c2aac007d40cd)
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 
msm6242_read(struct msm6242_priv * priv,unsigned int reg)79 static inline unsigned int msm6242_read(struct msm6242_priv *priv,
80 				       unsigned int reg)
81 {
82 	return __raw_readl(&priv->regs[reg]) & 0xf;
83 }
84 
msm6242_write(struct msm6242_priv * priv,unsigned int val,unsigned int reg)85 static 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 
msm6242_lock(struct msm6242_priv * priv)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, 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 
msm6242_unlock(struct msm6242_priv * priv)109 static void msm6242_unlock(struct msm6242_priv *priv)
110 {
111 	msm6242_write(priv, MSM6242_CD_IRQ_FLAG, MSM6242_CD);
112 }
113 
msm6242_read_time(struct device * dev,struct rtc_time * tm)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, 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 
msm6242_set_time(struct device * dev,struct rtc_time * tm)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, 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 
184 static const struct rtc_class_ops msm6242_rtc_ops = {
185 	.read_time	= msm6242_read_time,
186 	.set_time	= msm6242_set_time,
187 };
188 
msm6242_rtc_probe(struct platform_device * pdev)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(&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 
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