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1 /* |
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2 * include/asm-generic/rtc.h |
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3 * |
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4 * Author: Tom Rini <trini@mvista.com> |
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5 * |
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6 * Based on: |
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7 * drivers/char/rtc.c |
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8 * |
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9 * Please read the COPYING file for all license details. |
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10 */ |
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11 |
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12 #ifndef __ASM_RTC_H__ |
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13 #define __ASM_RTC_H__ |
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14 |
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15 #include <linux/mc146818rtc.h> |
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16 #include <linux/rtc.h> |
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17 #include <linux/bcd.h> |
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18 #include <linux/delay.h> |
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19 |
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20 #define RTC_PIE 0x40 /* periodic interrupt enable */ |
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21 #define RTC_AIE 0x20 /* alarm interrupt enable */ |
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22 #define RTC_UIE 0x10 /* update-finished interrupt enable */ |
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23 |
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24 /* some dummy definitions */ |
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25 #define RTC_BATT_BAD 0x100 /* battery bad */ |
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26 #define RTC_SQWE 0x08 /* enable square-wave output */ |
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27 #define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */ |
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28 #define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */ |
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29 #define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */ |
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30 |
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31 /* |
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32 * Returns true if a clock update is in progress |
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33 */ |
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34 static inline unsigned char rtc_is_updating(void) |
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35 { |
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36 unsigned char uip; |
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37 unsigned long flags; |
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38 |
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39 spin_lock_irqsave(&rtc_lock, flags); |
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40 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); |
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41 spin_unlock_irqrestore(&rtc_lock, flags); |
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42 return uip; |
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43 } |
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44 |
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45 static inline unsigned int get_rtc_time(struct rtc_time *time) |
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46 { |
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47 unsigned char ctrl; |
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48 unsigned long flags; |
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49 |
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50 #ifdef CONFIG_MACH_DECSTATION |
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51 unsigned int real_year; |
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52 #endif |
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53 |
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54 /* |
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55 * read RTC once any update in progress is done. The update |
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56 * can take just over 2ms. We wait 20ms. There is no need to |
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57 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. |
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58 * If you need to know *exactly* when a second has started, enable |
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59 * periodic update complete interrupts, (via ioctl) and then |
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60 * immediately read /dev/rtc which will block until you get the IRQ. |
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61 * Once the read clears, read the RTC time (again via ioctl). Easy. |
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62 */ |
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63 if (rtc_is_updating()) |
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64 mdelay(20); |
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65 |
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66 /* |
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67 * Only the values that we read from the RTC are set. We leave |
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68 * tm_wday, tm_yday and tm_isdst untouched. Even though the |
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69 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated |
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70 * by the RTC when initially set to a non-zero value. |
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71 */ |
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72 spin_lock_irqsave(&rtc_lock, flags); |
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73 time->tm_sec = CMOS_READ(RTC_SECONDS); |
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74 time->tm_min = CMOS_READ(RTC_MINUTES); |
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75 time->tm_hour = CMOS_READ(RTC_HOURS); |
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76 time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); |
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77 time->tm_mon = CMOS_READ(RTC_MONTH); |
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78 time->tm_year = CMOS_READ(RTC_YEAR); |
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79 #ifdef CONFIG_MACH_DECSTATION |
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80 real_year = CMOS_READ(RTC_DEC_YEAR); |
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81 #endif |
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82 ctrl = CMOS_READ(RTC_CONTROL); |
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83 spin_unlock_irqrestore(&rtc_lock, flags); |
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84 |
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85 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
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86 { |
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87 time->tm_sec = bcd2bin(time->tm_sec); |
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88 time->tm_min = bcd2bin(time->tm_min); |
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89 time->tm_hour = bcd2bin(time->tm_hour); |
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90 time->tm_mday = bcd2bin(time->tm_mday); |
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91 time->tm_mon = bcd2bin(time->tm_mon); |
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92 time->tm_year = bcd2bin(time->tm_year); |
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93 } |
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94 |
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95 #ifdef CONFIG_MACH_DECSTATION |
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96 time->tm_year += real_year - 72; |
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97 #endif |
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98 |
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99 /* |
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100 * Account for differences between how the RTC uses the values |
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101 * and how they are defined in a struct rtc_time; |
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102 */ |
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103 if (time->tm_year <= 69) |
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104 time->tm_year += 100; |
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105 |
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106 time->tm_mon--; |
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107 |
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108 return RTC_24H; |
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109 } |
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110 |
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111 /* Set the current date and time in the real time clock. */ |
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112 static inline int set_rtc_time(struct rtc_time *time) |
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113 { |
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114 unsigned long flags; |
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115 unsigned char mon, day, hrs, min, sec; |
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116 unsigned char save_control, save_freq_select; |
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117 unsigned int yrs; |
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118 #ifdef CONFIG_MACH_DECSTATION |
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119 unsigned int real_yrs, leap_yr; |
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120 #endif |
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121 |
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122 yrs = time->tm_year; |
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123 mon = time->tm_mon + 1; /* tm_mon starts at zero */ |
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124 day = time->tm_mday; |
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125 hrs = time->tm_hour; |
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126 min = time->tm_min; |
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127 sec = time->tm_sec; |
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128 |
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129 if (yrs > 255) /* They are unsigned */ |
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130 return -EINVAL; |
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131 |
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132 spin_lock_irqsave(&rtc_lock, flags); |
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133 #ifdef CONFIG_MACH_DECSTATION |
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134 real_yrs = yrs; |
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135 leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) || |
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136 !((yrs + 1900) % 400)); |
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137 yrs = 72; |
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138 |
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139 /* |
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140 * We want to keep the year set to 73 until March |
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141 * for non-leap years, so that Feb, 29th is handled |
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142 * correctly. |
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143 */ |
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144 if (!leap_yr && mon < 3) { |
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145 real_yrs--; |
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146 yrs = 73; |
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147 } |
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148 #endif |
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149 /* These limits and adjustments are independent of |
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150 * whether the chip is in binary mode or not. |
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151 */ |
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152 if (yrs > 169) { |
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153 spin_unlock_irqrestore(&rtc_lock, flags); |
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154 return -EINVAL; |
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155 } |
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156 |
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157 if (yrs >= 100) |
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158 yrs -= 100; |
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159 |
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160 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) |
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161 || RTC_ALWAYS_BCD) { |
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162 sec = bin2bcd(sec); |
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163 min = bin2bcd(min); |
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164 hrs = bin2bcd(hrs); |
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165 day = bin2bcd(day); |
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166 mon = bin2bcd(mon); |
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167 yrs = bin2bcd(yrs); |
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168 } |
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169 |
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170 save_control = CMOS_READ(RTC_CONTROL); |
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171 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); |
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172 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); |
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173 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); |
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174 |
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175 #ifdef CONFIG_MACH_DECSTATION |
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176 CMOS_WRITE(real_yrs, RTC_DEC_YEAR); |
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177 #endif |
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178 CMOS_WRITE(yrs, RTC_YEAR); |
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179 CMOS_WRITE(mon, RTC_MONTH); |
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180 CMOS_WRITE(day, RTC_DAY_OF_MONTH); |
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181 CMOS_WRITE(hrs, RTC_HOURS); |
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182 CMOS_WRITE(min, RTC_MINUTES); |
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183 CMOS_WRITE(sec, RTC_SECONDS); |
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184 |
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185 CMOS_WRITE(save_control, RTC_CONTROL); |
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186 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); |
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187 |
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188 spin_unlock_irqrestore(&rtc_lock, flags); |
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189 |
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190 return 0; |
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191 } |
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192 |
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193 static inline unsigned int get_rtc_ss(void) |
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194 { |
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195 struct rtc_time h; |
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196 |
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197 get_rtc_time(&h); |
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198 return h.tm_sec; |
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199 } |
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200 |
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201 static inline int get_rtc_pll(struct rtc_pll_info *pll) |
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202 { |
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203 return -EINVAL; |
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204 } |
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205 static inline int set_rtc_pll(struct rtc_pll_info *pll) |
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206 { |
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207 return -EINVAL; |
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208 } |
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209 |
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210 #endif /* __ASM_RTC_H__ */ |