aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorThomas Bogendoerfer <tsbogend@alpha.franken.de>2008-10-14 11:17:32 -0400
committerRalf Baechle <ralf@linux-mips.org>2008-10-15 07:46:51 -0400
commitd1dbd82e2ff02181a7102088a9fe83e17ddbcb47 (patch)
tree464587b752de7756bf45de8b31744ccb17710385
parent3ec066cdb75fb0ece5d4cc1ddfa93392f0f6498a (diff)
RTC: M48T35: new RTC driver
This driver replaces the broken ip27-rtc driver in drivers/char and gives back RTC support for SGI IP27 machines. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--drivers/rtc/Kconfig9
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/rtc-m48t35.c234
3 files changed, 244 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 24217008aa35..f3d7fd3406a6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -410,6 +410,15 @@ config RTC_DRV_M48T86
410 This driver can also be built as a module. If so, the module 410 This driver can also be built as a module. If so, the module
411 will be called rtc-m48t86. 411 will be called rtc-m48t86.
412 412
413config RTC_DRV_M48T35
414 tristate "ST M48T35"
415 help
416 If you say Y here you will get support for the
417 ST M48T35 RTC chip.
418
419 This driver can also be built as a module, if so, the module
420 will be called "rtc-m48t35".
421
413config RTC_DRV_M48T59 422config RTC_DRV_M48T59
414 tristate "ST M48T59/M48T08/M48T02" 423 tristate "ST M48T59/M48T08/M48T02"
415 help 424 help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index a3208082565c..37a71b727262 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_RTC_DRV_FM3130) += rtc-fm3130.o
37obj-$(CONFIG_RTC_DRV_ISL1208) += rtc-isl1208.o 37obj-$(CONFIG_RTC_DRV_ISL1208) += rtc-isl1208.o
38obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o 38obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o
39obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o 39obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o
40obj-$(CONFIG_RTC_DRV_M48T35) += rtc-m48t35.o
40obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o 41obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o
41obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o 42obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
42obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o 43obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o
diff --git a/drivers/rtc/rtc-m48t35.c b/drivers/rtc/rtc-m48t35.c
new file mode 100644
index 000000000000..b9c1fe4a198e
--- /dev/null
+++ b/drivers/rtc/rtc-m48t35.c
@@ -0,0 +1,234 @@
1/*
2 * Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
3 *
4 * Copyright (C) 2000 Silicon Graphics, Inc.
5 * Written by Ulf Carlsson (ulfc@engr.sgi.com)
6 *
7 * Copyright (C) 2008 Thomas Bogendoerfer
8 *
9 * Based on code written by Paul Gortmaker.
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
15 */
16
17#include <linux/module.h>
18#include <linux/rtc.h>
19#include <linux/platform_device.h>
20#include <linux/bcd.h>
21
22#define DRV_VERSION "1.0"
23
24struct m48t35_rtc {
25 u8 pad[0x7ff8]; /* starts at 0x7ff8 */
26 u8 control;
27 u8 sec;
28 u8 min;
29 u8 hour;
30 u8 day;
31 u8 date;
32 u8 month;
33 u8 year;
34};
35
36#define M48T35_RTC_SET 0x80
37#define M48T35_RTC_READ 0x40
38
39struct m48t35_priv {
40 struct rtc_device *rtc;
41 struct m48t35_rtc __iomem *reg;
42 size_t size;
43 unsigned long baseaddr;
44 spinlock_t lock;
45};
46
47static int m48t35_read_time(struct device *dev, struct rtc_time *tm)
48{
49 struct m48t35_priv *priv = dev_get_drvdata(dev);
50 u8 control;
51
52 /*
53 * Only the values that we read from the RTC are set. We leave
54 * tm_wday, tm_yday and tm_isdst untouched. Even though the
55 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
56 * by the RTC when initially set to a non-zero value.
57 */
58 spin_lock_irq(&priv->lock);
59 control = readb(&priv->reg->control);
60 writeb(control | M48T35_RTC_READ, &priv->reg->control);
61 tm->tm_sec = readb(&priv->reg->sec);
62 tm->tm_min = readb(&priv->reg->min);
63 tm->tm_hour = readb(&priv->reg->hour);
64 tm->tm_mday = readb(&priv->reg->date);
65 tm->tm_mon = readb(&priv->reg->month);
66 tm->tm_year = readb(&priv->reg->year);
67 writeb(control, &priv->reg->control);
68 spin_unlock_irq(&priv->lock);
69
70 tm->tm_sec = bcd2bin(tm->tm_sec);
71 tm->tm_min = bcd2bin(tm->tm_min);
72 tm->tm_hour = bcd2bin(tm->tm_hour);
73 tm->tm_mday = bcd2bin(tm->tm_mday);
74 tm->tm_mon = bcd2bin(tm->tm_mon);
75 tm->tm_year = bcd2bin(tm->tm_year);
76
77 /*
78 * Account for differences between how the RTC uses the values
79 * and how they are defined in a struct rtc_time;
80 */
81 tm->tm_year += 70;
82 if (tm->tm_year <= 69)
83 tm->tm_year += 100;
84
85 tm->tm_mon--;
86 return rtc_valid_tm(tm);
87}
88
89static int m48t35_set_time(struct device *dev, struct rtc_time *tm)
90{
91 struct m48t35_priv *priv = dev_get_drvdata(dev);
92 unsigned char mon, day, hrs, min, sec;
93 unsigned int yrs;
94 u8 control;
95
96 yrs = tm->tm_year + 1900;
97 mon = tm->tm_mon + 1; /* tm_mon starts at zero */
98 day = tm->tm_mday;
99 hrs = tm->tm_hour;
100 min = tm->tm_min;
101 sec = tm->tm_sec;
102
103 if (yrs < 1970)
104 return -EINVAL;
105
106 yrs -= 1970;
107 if (yrs > 255) /* They are unsigned */
108 return -EINVAL;
109
110 if (yrs > 169)
111 return -EINVAL;
112
113 if (yrs >= 100)
114 yrs -= 100;
115
116 sec = bin2bcd(sec);
117 min = bin2bcd(min);
118 hrs = bin2bcd(hrs);
119 day = bin2bcd(day);
120 mon = bin2bcd(mon);
121 yrs = bin2bcd(yrs);
122
123 spin_lock_irq(&priv->lock);
124 control = readb(&priv->reg->control);
125 writeb(control | M48T35_RTC_SET, &priv->reg->control);
126 writeb(yrs, &priv->reg->year);
127 writeb(mon, &priv->reg->month);
128 writeb(day, &priv->reg->date);
129 writeb(hrs, &priv->reg->hour);
130 writeb(min, &priv->reg->min);
131 writeb(sec, &priv->reg->sec);
132 writeb(control, &priv->reg->control);
133 spin_unlock_irq(&priv->lock);
134 return 0;
135}
136
137static const struct rtc_class_ops m48t35_ops = {
138 .read_time = m48t35_read_time,
139 .set_time = m48t35_set_time,
140};
141
142static int __devinit m48t35_probe(struct platform_device *pdev)
143{
144 struct rtc_device *rtc;
145 struct resource *res;
146 struct m48t35_priv *priv;
147 int ret = 0;
148
149 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
150 if (!res)
151 return -ENODEV;
152 priv = kzalloc(sizeof(struct m48t35_priv), GFP_KERNEL);
153 if (!priv)
154 return -ENOMEM;
155
156 priv->size = res->end - res->start + 1;
157 /*
158 * kludge: remove the #ifndef after ioc3 resource
159 * conflicts are resolved
160 */
161#ifndef CONFIG_SGI_IP27
162 if (!request_mem_region(res->start, priv->size, pdev->name)) {
163 ret = -EBUSY;
164 goto out;
165 }
166#endif
167 priv->baseaddr = res->start;
168 priv->reg = ioremap(priv->baseaddr, priv->size);
169 if (!priv->reg) {
170 ret = -ENOMEM;
171 goto out;
172 }
173 spin_lock_init(&priv->lock);
174 rtc = rtc_device_register("m48t35", &pdev->dev,
175 &m48t35_ops, THIS_MODULE);
176 if (IS_ERR(rtc)) {
177 ret = PTR_ERR(rtc);
178 goto out;
179 }
180 priv->rtc = rtc;
181 platform_set_drvdata(pdev, priv);
182 return 0;
183
184out:
185 if (priv->rtc)
186 rtc_device_unregister(priv->rtc);
187 if (priv->reg)
188 iounmap(priv->reg);
189 if (priv->baseaddr)
190 release_mem_region(priv->baseaddr, priv->size);
191 kfree(priv);
192 return ret;
193}
194
195static int __devexit m48t35_remove(struct platform_device *pdev)
196{
197 struct m48t35_priv *priv = platform_get_drvdata(pdev);
198
199 rtc_device_unregister(priv->rtc);
200 iounmap(priv->reg);
201#ifndef CONFIG_SGI_IP27
202 release_mem_region(priv->baseaddr, priv->size);
203#endif
204 kfree(priv);
205 return 0;
206}
207
208static struct platform_driver m48t35_platform_driver = {
209 .driver = {
210 .name = "rtc-m48t35",
211 .owner = THIS_MODULE,
212 },
213 .probe = m48t35_probe,
214 .remove = __devexit_p(m48t35_remove),
215};
216
217static int __init m48t35_init(void)
218{
219 return platform_driver_register(&m48t35_platform_driver);
220}
221
222static void __exit m48t35_exit(void)
223{
224 platform_driver_unregister(&m48t35_platform_driver);
225}
226
227MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
228MODULE_DESCRIPTION("M48T35 RTC driver");
229MODULE_LICENSE("GPL");
230MODULE_VERSION(DRV_VERSION);
231MODULE_ALIAS("platform:rtc-m48t35");
232
233module_init(m48t35_init);
234module_exit(m48t35_exit);