1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Real Time Clock interface for Linux on the MVME16x |
4 | * |
5 | * Based on the PC driver by Paul Gortmaker. |
6 | */ |
7 | |
8 | #define RTC_VERSION "1.00" |
9 | |
10 | #include <linux/types.h> |
11 | #include <linux/errno.h> |
12 | #include <linux/miscdevice.h> |
13 | #include <linux/ioport.h> |
14 | #include <linux/capability.h> |
15 | #include <linux/fcntl.h> |
16 | #include <linux/init.h> |
17 | #include <linux/poll.h> |
18 | #include <linux/rtc.h> /* For struct rtc_time and ioctls, etc */ |
19 | #include <linux/bcd.h> |
20 | #include <asm/mvme16xhw.h> |
21 | |
22 | #include <asm/io.h> |
23 | #include <linux/uaccess.h> |
24 | #include <asm/setup.h> |
25 | |
26 | /* |
27 | * We sponge a minor off of the misc major. No need slurping |
28 | * up another valuable major dev number for this. If you add |
29 | * an ioctl, make sure you don't conflict with SPARC's RTC |
30 | * ioctls. |
31 | */ |
32 | |
33 | static const unsigned char days_in_mo[] = |
34 | {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; |
35 | |
36 | static atomic_t rtc_ready = ATOMIC_INIT(1); |
37 | |
38 | static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
39 | { |
40 | volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE; |
41 | unsigned long flags; |
42 | struct rtc_time wtime; |
43 | void __user *argp = (void __user *)arg; |
44 | |
45 | switch (cmd) { |
46 | case RTC_RD_TIME: /* Read the time/date from RTC */ |
47 | { |
48 | local_irq_save(flags); |
49 | /* Ensure clock and real-time-mode-register are accessible */ |
50 | rtc->ctrl = RTC_READ; |
51 | memset(&wtime, 0, sizeof(struct rtc_time)); |
52 | wtime.tm_sec = bcd2bin(rtc->bcd_sec); |
53 | wtime.tm_min = bcd2bin(rtc->bcd_min); |
54 | wtime.tm_hour = bcd2bin(rtc->bcd_hr); |
55 | wtime.tm_mday = bcd2bin(rtc->bcd_dom); |
56 | wtime.tm_mon = bcd2bin(rtc->bcd_mth)-1; |
57 | wtime.tm_year = bcd2bin(rtc->bcd_year); |
58 | if (wtime.tm_year < 70) |
59 | wtime.tm_year += 100; |
60 | wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1; |
61 | rtc->ctrl = 0; |
62 | local_irq_restore(flags); |
63 | return copy_to_user(to: argp, from: &wtime, n: sizeof wtime) ? |
64 | -EFAULT : 0; |
65 | } |
66 | case RTC_SET_TIME: /* Set the RTC */ |
67 | { |
68 | struct rtc_time rtc_tm; |
69 | unsigned char mon, day, hrs, min, sec, leap_yr; |
70 | unsigned int yrs; |
71 | |
72 | if (!capable(CAP_SYS_ADMIN)) |
73 | return -EACCES; |
74 | |
75 | if (copy_from_user(to: &rtc_tm, from: argp, n: sizeof(struct rtc_time))) |
76 | return -EFAULT; |
77 | |
78 | yrs = rtc_tm.tm_year; |
79 | if (yrs < 1900) |
80 | yrs += 1900; |
81 | mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ |
82 | day = rtc_tm.tm_mday; |
83 | hrs = rtc_tm.tm_hour; |
84 | min = rtc_tm.tm_min; |
85 | sec = rtc_tm.tm_sec; |
86 | |
87 | leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); |
88 | |
89 | if ((mon > 12) || (day == 0)) |
90 | return -EINVAL; |
91 | |
92 | if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) |
93 | return -EINVAL; |
94 | |
95 | if ((hrs >= 24) || (min >= 60) || (sec >= 60)) |
96 | return -EINVAL; |
97 | |
98 | if (yrs >= 2070) |
99 | return -EINVAL; |
100 | |
101 | local_irq_save(flags); |
102 | rtc->ctrl = RTC_WRITE; |
103 | |
104 | rtc->bcd_sec = bin2bcd(sec); |
105 | rtc->bcd_min = bin2bcd(min); |
106 | rtc->bcd_hr = bin2bcd(hrs); |
107 | rtc->bcd_dom = bin2bcd(day); |
108 | rtc->bcd_mth = bin2bcd(mon); |
109 | rtc->bcd_year = bin2bcd(yrs%100); |
110 | |
111 | rtc->ctrl = 0; |
112 | local_irq_restore(flags); |
113 | return 0; |
114 | } |
115 | default: |
116 | return -EINVAL; |
117 | } |
118 | } |
119 | |
120 | /* |
121 | * We enforce only one user at a time here with the open/close. |
122 | */ |
123 | static int rtc_open(struct inode *inode, struct file *file) |
124 | { |
125 | if( !atomic_dec_and_test(v: &rtc_ready) ) |
126 | { |
127 | atomic_inc( v: &rtc_ready ); |
128 | return -EBUSY; |
129 | } |
130 | return 0; |
131 | } |
132 | |
133 | static int rtc_release(struct inode *inode, struct file *file) |
134 | { |
135 | atomic_inc( v: &rtc_ready ); |
136 | return 0; |
137 | } |
138 | |
139 | /* |
140 | * The various file operations we support. |
141 | */ |
142 | |
143 | static const struct file_operations rtc_fops = { |
144 | .unlocked_ioctl = rtc_ioctl, |
145 | .open = rtc_open, |
146 | .release = rtc_release, |
147 | .llseek = noop_llseek, |
148 | }; |
149 | |
150 | static struct miscdevice rtc_dev= |
151 | { |
152 | .minor = RTC_MINOR, |
153 | .name = "rtc" , |
154 | .fops = &rtc_fops |
155 | }; |
156 | |
157 | static int __init rtc_MK48T08_init(void) |
158 | { |
159 | if (!MACH_IS_MVME16x) |
160 | return -ENODEV; |
161 | |
162 | pr_info("MK48T08 Real Time Clock Driver v%s\n" , RTC_VERSION); |
163 | return misc_register(misc: &rtc_dev); |
164 | } |
165 | device_initcall(rtc_MK48T08_init); |
166 | |