Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 2 | * include/asm-generic/rtc.h |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Author: Tom Rini <trini@mvista.com> |
| 5 | * |
| 6 | * Based on: |
| 7 | * drivers/char/rtc.c |
| 8 | * |
| 9 | * Please read the COPYING file for all license details. |
| 10 | */ |
| 11 | |
| 12 | #ifndef __ASM_RTC_H__ |
| 13 | #define __ASM_RTC_H__ |
| 14 | |
| 15 | #ifdef __KERNEL__ |
| 16 | |
| 17 | #include <linux/mc146818rtc.h> |
| 18 | #include <linux/rtc.h> |
| 19 | #include <linux/bcd.h> |
| 20 | |
| 21 | #define RTC_PIE 0x40 /* periodic interrupt enable */ |
| 22 | #define RTC_AIE 0x20 /* alarm interrupt enable */ |
| 23 | #define RTC_UIE 0x10 /* update-finished interrupt enable */ |
| 24 | |
| 25 | /* some dummy definitions */ |
| 26 | #define RTC_BATT_BAD 0x100 /* battery bad */ |
| 27 | #define RTC_SQWE 0x08 /* enable square-wave output */ |
| 28 | #define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */ |
| 29 | #define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */ |
| 30 | #define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */ |
| 31 | |
| 32 | /* |
| 33 | * Returns true if a clock update is in progress |
| 34 | */ |
| 35 | static inline unsigned char rtc_is_updating(void) |
| 36 | { |
| 37 | unsigned char uip; |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 38 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 40 | spin_lock_irqsave(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 42 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | return uip; |
| 44 | } |
| 45 | |
| 46 | static inline unsigned int get_rtc_time(struct rtc_time *time) |
| 47 | { |
| 48 | unsigned long uip_watchdog = jiffies; |
| 49 | unsigned char ctrl; |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 50 | unsigned long flags; |
| 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #ifdef CONFIG_MACH_DECSTATION |
| 53 | unsigned int real_year; |
| 54 | #endif |
| 55 | |
| 56 | /* |
| 57 | * read RTC once any update in progress is done. The update |
| 58 | * can take just over 2ms. We wait 10 to 20ms. There is no need to |
| 59 | * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. |
| 60 | * If you need to know *exactly* when a second has started, enable |
| 61 | * periodic update complete interrupts, (via ioctl) and then |
| 62 | * immediately read /dev/rtc which will block until you get the IRQ. |
| 63 | * Once the read clears, read the RTC time (again via ioctl). Easy. |
| 64 | */ |
| 65 | |
| 66 | if (rtc_is_updating() != 0) |
| 67 | while (jiffies - uip_watchdog < 2*HZ/100) { |
| 68 | barrier(); |
| 69 | cpu_relax(); |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * Only the values that we read from the RTC are set. We leave |
| 74 | * tm_wday, tm_yday and tm_isdst untouched. Even though the |
| 75 | * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated |
| 76 | * by the RTC when initially set to a non-zero value. |
| 77 | */ |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 78 | spin_lock_irqsave(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | time->tm_sec = CMOS_READ(RTC_SECONDS); |
| 80 | time->tm_min = CMOS_READ(RTC_MINUTES); |
| 81 | time->tm_hour = CMOS_READ(RTC_HOURS); |
| 82 | time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); |
| 83 | time->tm_mon = CMOS_READ(RTC_MONTH); |
| 84 | time->tm_year = CMOS_READ(RTC_YEAR); |
| 85 | #ifdef CONFIG_MACH_DECSTATION |
| 86 | real_year = CMOS_READ(RTC_DEC_YEAR); |
| 87 | #endif |
| 88 | ctrl = CMOS_READ(RTC_CONTROL); |
Andrew Morton | 795d45b | 2008-02-04 16:48:10 +0100 | [diff] [blame] | 89 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
| 91 | if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
| 92 | { |
| 93 | BCD_TO_BIN(time->tm_sec); |
| 94 | BCD_TO_BIN(time->tm_min); |
| 95 | BCD_TO_BIN(time->tm_hour); |
| 96 | BCD_TO_BIN(time->tm_mday); |
| 97 | BCD_TO_BIN(time->tm_mon); |
| 98 | BCD_TO_BIN(time->tm_year); |
| 99 | } |
| 100 | |
| 101 | #ifdef CONFIG_MACH_DECSTATION |
| 102 | time->tm_year += real_year - 72; |
| 103 | #endif |
| 104 | |
| 105 | /* |
| 106 | * Account for differences between how the RTC uses the values |
| 107 | * and how they are defined in a struct rtc_time; |
| 108 | */ |
| 109 | if (time->tm_year <= 69) |
| 110 | time->tm_year += 100; |
| 111 | |
| 112 | time->tm_mon--; |
| 113 | |
| 114 | return RTC_24H; |
| 115 | } |
| 116 | |
| 117 | /* Set the current date and time in the real time clock. */ |
| 118 | static inline int set_rtc_time(struct rtc_time *time) |
| 119 | { |
Linus Torvalds | eb71c87 | 2006-06-24 14:27:42 -0700 | [diff] [blame] | 120 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | unsigned char mon, day, hrs, min, sec; |
| 122 | unsigned char save_control, save_freq_select; |
| 123 | unsigned int yrs; |
| 124 | #ifdef CONFIG_MACH_DECSTATION |
| 125 | unsigned int real_yrs, leap_yr; |
| 126 | #endif |
| 127 | |
| 128 | yrs = time->tm_year; |
| 129 | mon = time->tm_mon + 1; /* tm_mon starts at zero */ |
| 130 | day = time->tm_mday; |
| 131 | hrs = time->tm_hour; |
| 132 | min = time->tm_min; |
| 133 | sec = time->tm_sec; |
| 134 | |
| 135 | if (yrs > 255) /* They are unsigned */ |
| 136 | return -EINVAL; |
| 137 | |
Linus Torvalds | eb71c87 | 2006-06-24 14:27:42 -0700 | [diff] [blame] | 138 | spin_lock_irqsave(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | #ifdef CONFIG_MACH_DECSTATION |
| 140 | real_yrs = yrs; |
| 141 | leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) || |
| 142 | !((yrs + 1900) % 400)); |
| 143 | yrs = 72; |
| 144 | |
| 145 | /* |
| 146 | * We want to keep the year set to 73 until March |
| 147 | * for non-leap years, so that Feb, 29th is handled |
| 148 | * correctly. |
| 149 | */ |
| 150 | if (!leap_yr && mon < 3) { |
| 151 | real_yrs--; |
| 152 | yrs = 73; |
| 153 | } |
| 154 | #endif |
| 155 | /* These limits and adjustments are independent of |
| 156 | * whether the chip is in binary mode or not. |
| 157 | */ |
| 158 | if (yrs > 169) { |
Linus Torvalds | eb71c87 | 2006-06-24 14:27:42 -0700 | [diff] [blame] | 159 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | return -EINVAL; |
| 161 | } |
| 162 | |
| 163 | if (yrs >= 100) |
| 164 | yrs -= 100; |
| 165 | |
| 166 | if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) |
| 167 | || RTC_ALWAYS_BCD) { |
| 168 | BIN_TO_BCD(sec); |
| 169 | BIN_TO_BCD(min); |
| 170 | BIN_TO_BCD(hrs); |
| 171 | BIN_TO_BCD(day); |
| 172 | BIN_TO_BCD(mon); |
| 173 | BIN_TO_BCD(yrs); |
| 174 | } |
| 175 | |
| 176 | save_control = CMOS_READ(RTC_CONTROL); |
| 177 | CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); |
| 178 | save_freq_select = CMOS_READ(RTC_FREQ_SELECT); |
| 179 | CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); |
| 180 | |
| 181 | #ifdef CONFIG_MACH_DECSTATION |
| 182 | CMOS_WRITE(real_yrs, RTC_DEC_YEAR); |
| 183 | #endif |
| 184 | CMOS_WRITE(yrs, RTC_YEAR); |
| 185 | CMOS_WRITE(mon, RTC_MONTH); |
| 186 | CMOS_WRITE(day, RTC_DAY_OF_MONTH); |
| 187 | CMOS_WRITE(hrs, RTC_HOURS); |
| 188 | CMOS_WRITE(min, RTC_MINUTES); |
| 189 | CMOS_WRITE(sec, RTC_SECONDS); |
| 190 | |
| 191 | CMOS_WRITE(save_control, RTC_CONTROL); |
| 192 | CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); |
| 193 | |
Linus Torvalds | eb71c87 | 2006-06-24 14:27:42 -0700 | [diff] [blame] | 194 | spin_unlock_irqrestore(&rtc_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | static inline unsigned int get_rtc_ss(void) |
| 200 | { |
| 201 | struct rtc_time h; |
| 202 | |
| 203 | get_rtc_time(&h); |
| 204 | return h.tm_sec; |
| 205 | } |
| 206 | |
| 207 | static inline int get_rtc_pll(struct rtc_pll_info *pll) |
| 208 | { |
| 209 | return -EINVAL; |
| 210 | } |
| 211 | static inline int set_rtc_pll(struct rtc_pll_info *pll) |
| 212 | { |
| 213 | return -EINVAL; |
| 214 | } |
| 215 | |
| 216 | #endif /* __KERNEL__ */ |
| 217 | #endif /* __ASM_RTC_H__ */ |