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authorManuel Lauss <mano@roarinelk.homelinux.net>2009-01-06 17:42:18 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 18:59:24 -0500
commit45fd8a0c14884b2d8f2a31f71c72dedbaeeb33f2 (patch)
tree858e24c5511de2c9efe10de6a738a815a593d02c /drivers/rtc
parentae64d16956718bfd11955217f603b27a781c0cb1 (diff)
rtc: Au1000 On-Chip Counter0-as-RTC driver.
Simple driver which uses the Au1xxx Time-Of-Year counter (counter0) as a 1Hz RTC. [akpm@linux-foundation.org: repair Kconfig] Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/Kconfig10
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/rtc-au1xxx.c153
3 files changed, 164 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 92c2db64de9c..3b1c7aa93e75 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -638,6 +638,16 @@ config RTC_DRV_AT91SAM9_GPBR
638 will be used. The default of zero is normally OK to use, but 638 will be used. The default of zero is normally OK to use, but
639 on some systems other software needs to use that register. 639 on some systems other software needs to use that register.
640 640
641config RTC_DRV_AU1XXX
642 tristate "Au1xxx Counter0 RTC support"
643 depends on SOC_AU1X00
644 help
645 This is a driver for the Au1xxx on-chip Counter0 (Time-Of-Year
646 counter) to be used as a RTC.
647
648 This driver can also be built as a module. If so, the module
649 will be called rtc-au1xxx.
650
641config RTC_DRV_BFIN 651config RTC_DRV_BFIN
642 tristate "Blackfin On-Chip RTC" 652 tristate "Blackfin On-Chip RTC"
643 depends on BLACKFIN && !BF561 653 depends on BLACKFIN && !BF561
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index eef9e337f202..fca0c9bf11c9 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -20,6 +20,7 @@ rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
20obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o 20obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
21obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o 21obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
22obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o 22obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o
23obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o
23obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o 24obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o
24obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o 25obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
25obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o 26obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o
diff --git a/drivers/rtc/rtc-au1xxx.c b/drivers/rtc/rtc-au1xxx.c
new file mode 100644
index 000000000000..8906a688e6a6
--- /dev/null
+++ b/drivers/rtc/rtc-au1xxx.c
@@ -0,0 +1,153 @@
1/*
2 * Au1xxx counter0 (aka Time-Of-Year counter) RTC interface driver.
3 *
4 * Copyright (C) 2008 Manuel Lauss <mano@roarinelk.homelinux.net>
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10
11/* All current Au1xxx SoCs have 2 counters fed by an external 32.768 kHz
12 * crystal. Counter 0, which keeps counting during sleep/powerdown, is
13 * used to count seconds since the beginning of the unix epoch.
14 *
15 * The counters must be configured and enabled by bootloader/board code;
16 * no checks as to whether they really get a proper 32.768kHz clock are
17 * made as this would take far too long.
18 */
19
20#include <linux/module.h>
21#include <linux/kernel.h>
22#include <linux/rtc.h>
23#include <linux/init.h>
24#include <linux/platform_device.h>
25#include <linux/io.h>
26#include <asm/mach-au1x00/au1000.h>
27
28/* 32kHz clock enabled and detected */
29#define CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
30
31static int au1xtoy_rtc_read_time(struct device *dev, struct rtc_time *tm)
32{
33 unsigned long t;
34
35 t = au_readl(SYS_TOYREAD);
36
37 rtc_time_to_tm(t, tm);
38
39 return rtc_valid_tm(tm);
40}
41
42static int au1xtoy_rtc_set_time(struct device *dev, struct rtc_time *tm)
43{
44 unsigned long t;
45
46 rtc_tm_to_time(tm, &t);
47
48 au_writel(t, SYS_TOYWRITE);
49 au_sync();
50
51 /* wait for the pending register write to succeed. This can
52 * take up to 6 seconds...
53 */
54 while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S)
55 msleep(1);
56
57 return 0;
58}
59
60static struct rtc_class_ops au1xtoy_rtc_ops = {
61 .read_time = au1xtoy_rtc_read_time,
62 .set_time = au1xtoy_rtc_set_time,
63};
64
65static int __devinit au1xtoy_rtc_probe(struct platform_device *pdev)
66{
67 struct rtc_device *rtcdev;
68 unsigned long t;
69 int ret;
70
71 t = au_readl(SYS_COUNTER_CNTRL);
72 if (!(t & CNTR_OK)) {
73 dev_err(&pdev->dev, "counters not working; aborting.\n");
74 ret = -ENODEV;
75 goto out_err;
76 }
77
78 ret = -ETIMEDOUT;
79
80 /* set counter0 tickrate to 1Hz if necessary */
81 if (au_readl(SYS_TOYTRIM) != 32767) {
82 /* wait until hardware gives access to TRIM register */
83 t = 0x00100000;
84 while ((au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T0S) && t--)
85 msleep(1);
86
87 if (!t) {
88 /* timed out waiting for register access; assume
89 * counters are unusable.
90 */
91 dev_err(&pdev->dev, "timeout waiting for access\n");
92 goto out_err;
93 }
94
95 /* set 1Hz TOY tick rate */
96 au_writel(32767, SYS_TOYTRIM);
97 au_sync();
98 }
99
100 /* wait until the hardware allows writes to the counter reg */
101 while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S)
102 msleep(1);
103
104 rtcdev = rtc_device_register("rtc-au1xxx", &pdev->dev,
105 &au1xtoy_rtc_ops, THIS_MODULE);
106 if (IS_ERR(rtcdev)) {
107 ret = PTR_ERR(rtcdev);
108 goto out_err;
109 }
110
111 platform_set_drvdata(pdev, rtcdev);
112
113 return 0;
114
115out_err:
116 return ret;
117}
118
119static int __devexit au1xtoy_rtc_remove(struct platform_device *pdev)
120{
121 struct rtc_device *rtcdev = platform_get_drvdata(pdev);
122
123 rtc_device_unregister(rtcdev);
124 platform_set_drvdata(pdev, NULL);
125
126 return 0;
127}
128
129static struct platform_driver au1xrtc_driver = {
130 .driver = {
131 .name = "rtc-au1xxx",
132 .owner = THIS_MODULE,
133 },
134 .remove = __devexit_p(au1xtoy_rtc_remove),
135};
136
137static int __init au1xtoy_rtc_init(void)
138{
139 return platform_driver_probe(&au1xrtc_driver, au1xtoy_rtc_probe);
140}
141
142static void __exit au1xtoy_rtc_exit(void)
143{
144 platform_driver_unregister(&au1xrtc_driver);
145}
146
147module_init(au1xtoy_rtc_init);
148module_exit(au1xtoy_rtc_exit);
149
150MODULE_DESCRIPTION("Au1xxx TOY-counter-based RTC driver");
151MODULE_AUTHOR("Manuel Lauss <manuel.lauss@gmail.com>");
152MODULE_LICENSE("GPL");
153MODULE_ALIAS("platform:rtc-au1xxx");