diff options
author | Manuel Lauss <mano@roarinelk.homelinux.net> | 2009-01-06 17:42:18 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 18:59:24 -0500 |
commit | 45fd8a0c14884b2d8f2a31f71c72dedbaeeb33f2 (patch) | |
tree | 858e24c5511de2c9efe10de6a738a815a593d02c /drivers/rtc | |
parent | ae64d16956718bfd11955217f603b27a781c0cb1 (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/Kconfig | 10 | ||||
-rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
-rw-r--r-- | drivers/rtc/rtc-au1xxx.c | 153 |
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 | ||
641 | config 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 | |||
641 | config RTC_DRV_BFIN | 651 | config 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-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o | |||
20 | obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o | 20 | obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o |
21 | obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o | 21 | obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o |
22 | obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o | 22 | obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o |
23 | obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o | ||
23 | obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o | 24 | obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o |
24 | obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o | 25 | obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o |
25 | obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o | 26 | obj-$(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 | |||
31 | static 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 | |||
42 | static 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 | |||
60 | static struct rtc_class_ops au1xtoy_rtc_ops = { | ||
61 | .read_time = au1xtoy_rtc_read_time, | ||
62 | .set_time = au1xtoy_rtc_set_time, | ||
63 | }; | ||
64 | |||
65 | static 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 | |||
115 | out_err: | ||
116 | return ret; | ||
117 | } | ||
118 | |||
119 | static 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 | |||
129 | static 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 | |||
137 | static int __init au1xtoy_rtc_init(void) | ||
138 | { | ||
139 | return platform_driver_probe(&au1xrtc_driver, au1xtoy_rtc_probe); | ||
140 | } | ||
141 | |||
142 | static void __exit au1xtoy_rtc_exit(void) | ||
143 | { | ||
144 | platform_driver_unregister(&au1xrtc_driver); | ||
145 | } | ||
146 | |||
147 | module_init(au1xtoy_rtc_init); | ||
148 | module_exit(au1xtoy_rtc_exit); | ||
149 | |||
150 | MODULE_DESCRIPTION("Au1xxx TOY-counter-based RTC driver"); | ||
151 | MODULE_AUTHOR("Manuel Lauss <manuel.lauss@gmail.com>"); | ||
152 | MODULE_LICENSE("GPL"); | ||
153 | MODULE_ALIAS("platform:rtc-au1xxx"); | ||