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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | /* |
| 2 | * Constant and architecture independent procedures |
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| 3 | * for NEC uPD4990A serial I/O real-time clock. |
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| 4 | * |
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| 5 | * Copyright 2001 TAKAI Kousuke <tak@kmc.kyoto-u.ac.jp> |
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| 6 | * Kyoto University Microcomputer Club (KMC). |
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| 7 | * |
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| 8 | * References: |
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| 9 | * uPD4990A serial I/O real-time clock users' manual (Japanese) |
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| 10 | * No. S12828JJ4V0UM00 (4th revision), NEC Corporation, 1999. |
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| 11 | */ |
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| 12 | |||
| 13 | #ifndef _LINUX_uPD4990A_H |
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| 14 | #define _LINUX_uPD4990A_H |
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| 15 | |||
| 16 | #include <asm/byteorder.h> |
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| 17 | |||
| 18 | #include <asm/upd4990a.h> |
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| 19 | |||
| 20 | /* Serial commands (4 bits) */ |
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| 21 | #define UPD4990A_REGISTER_HOLD (0x0) |
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| 22 | #define UPD4990A_REGISTER_SHIFT (0x1) |
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| 23 | #define UPD4990A_TIME_SET_AND_COUNTER_HOLD (0x2) |
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| 24 | #define UPD4990A_TIME_READ (0x3) |
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| 25 | #define UPD4990A_TP_64HZ (0x4) |
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| 26 | #define UPD4990A_TP_256HZ (0x5) |
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| 27 | #define UPD4990A_TP_2048HZ (0x6) |
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| 28 | #define UPD4990A_TP_4096HZ (0x7) |
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| 29 | #define UPD4990A_TP_1S (0x8) |
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| 30 | #define UPD4990A_TP_10S (0x9) |
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| 31 | #define UPD4990A_TP_30S (0xA) |
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| 32 | #define UPD4990A_TP_60S (0xB) |
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| 33 | #define UPD4990A_INTERRUPT_RESET (0xC) |
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| 34 | #define UPD4990A_INTERRUPT_TIMER_START (0xD) |
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| 35 | #define UPD4990A_INTERRUPT_TIMER_STOP (0xE) |
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| 36 | #define UPD4990A_TEST_MODE_SET (0xF) |
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| 37 | |||
| 38 | /* Parallel commands (3 bits) |
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| 39 | 0-6 are same with serial commands. */ |
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| 40 | #define UPD4990A_PAR_SERIAL_MODE 7 |
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| 41 | |||
| 42 | #ifndef UPD4990A_DELAY |
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| 43 | # include <linux/delay.h> |
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| 44 | # define UPD4990A_DELAY(usec) udelay((usec)) |
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| 45 | #endif |
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| 46 | #ifndef UPD4990A_OUTPUT_DATA |
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| 47 | # define UPD4990A_OUTPUT_DATA(bit) \ |
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| 48 | do { \ |
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| 49 | UPD4990A_OUTPUT_DATA_CLK((bit), 0); \ |
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| 50 | UPD4990A_DELAY(1); /* t-DSU */ \ |
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| 51 | UPD4990A_OUTPUT_DATA_CLK((bit), 1); \ |
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| 52 | UPD4990A_DELAY(1); /* t-DHLD */ \ |
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| 53 | } while (0) |
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| 54 | #endif |
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| 55 | |||
| 56 | static __inline__ void upd4990a_serial_command(int command) |
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| 57 | { |
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| 58 | UPD4990A_OUTPUT_DATA(command >> 0); |
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| 59 | UPD4990A_OUTPUT_DATA(command >> 1); |
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| 60 | UPD4990A_OUTPUT_DATA(command >> 2); |
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| 61 | UPD4990A_OUTPUT_DATA(command >> 3); |
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| 62 | UPD4990A_DELAY(1); /* t-HLD */ |
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| 63 | UPD4990A_OUTPUT_STROBE(1); |
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| 64 | UPD4990A_DELAY(1); /* t-STB & t-d1 */ |
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| 65 | UPD4990A_OUTPUT_STROBE(0); |
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| 66 | /* 19 microseconds extra delay is needed |
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| 67 | iff previous mode is TIME READ command */ |
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| 68 | } |
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| 69 | |||
| 70 | struct upd4990a_raw_data { |
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| 71 | u8 sec; /* BCD */ |
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| 72 | u8 min; /* BCD */ |
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| 73 | u8 hour; /* BCD */ |
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| 74 | u8 mday; /* BCD */ |
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| 75 | #if defined __LITTLE_ENDIAN_BITFIELD |
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| 76 | unsigned wday :4; /* 0-6 */ |
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| 77 | unsigned mon :4; /* 1-based */ |
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| 78 | #elif defined __BIG_ENDIAN_BITFIELD |
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| 79 | unsigned mon :4; /* 1-based */ |
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| 80 | unsigned wday :4; /* 0-6 */ |
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| 81 | #else |
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| 82 | # error Unknown bitfield endian! |
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| 83 | #endif |
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| 84 | u8 year; /* BCD */ |
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| 85 | }; |
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| 86 | |||
| 87 | static __inline__ void upd4990a_get_time(struct upd4990a_raw_data *buf, |
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| 88 | int leave_register_hold) |
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| 89 | { |
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| 90 | int byte; |
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| 91 | |||
| 92 | upd4990a_serial_command(UPD4990A_TIME_READ); |
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| 93 | upd4990a_serial_command(UPD4990A_REGISTER_SHIFT); |
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| 94 | UPD4990A_DELAY(19); /* t-d2 - t-d1 */ |
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| 95 | |||
| 96 | for (byte = 0; byte < 6; byte++) { |
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| 97 | u8 tmp; |
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| 98 | int bit; |
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| 99 | |||
| 100 | for (tmp = 0, bit = 0; bit < 8; bit++) { |
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| 101 | tmp = (tmp | (UPD4990A_READ_DATA() << 8)) >> 1; |
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| 102 | UPD4990A_OUTPUT_CLK(1); |
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| 103 | UPD4990A_DELAY(1); |
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| 104 | UPD4990A_OUTPUT_CLK(0); |
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| 105 | UPD4990A_DELAY(1); |
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| 106 | } |
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| 107 | ((u8 *) buf)[byte] = tmp; |
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| 108 | } |
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| 109 | |||
| 110 | /* The uPD4990A users' manual says that we should issue `Register |
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| 111 | Hold' command after each data retrieval, or next `Time Read' |
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| 112 | command may not work correctly. */ |
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| 113 | if (!leave_register_hold) |
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| 114 | upd4990a_serial_command(UPD4990A_REGISTER_HOLD); |
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| 115 | } |
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| 116 | |||
| 117 | static __inline__ void upd4990a_set_time(const struct upd4990a_raw_data *data, |
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| 118 | int time_set_only) |
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| 119 | { |
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| 120 | int byte; |
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| 121 | |||
| 122 | if (!time_set_only) |
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| 123 | upd4990a_serial_command(UPD4990A_REGISTER_SHIFT); |
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| 124 | |||
| 125 | for (byte = 0; byte < 6; byte++) { |
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| 126 | int bit; |
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| 127 | u8 tmp = ((const u8 *) data)[byte]; |
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| 128 | |||
| 129 | for (bit = 0; bit < 8; bit++, tmp >>= 1) |
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| 130 | UPD4990A_OUTPUT_DATA(tmp); |
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| 131 | } |
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| 132 | |||
| 133 | upd4990a_serial_command(UPD4990A_TIME_SET_AND_COUNTER_HOLD); |
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| 134 | |||
| 135 | /* Release counter hold and start the clock. */ |
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| 136 | if (!time_set_only) |
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| 137 | upd4990a_serial_command(UPD4990A_REGISTER_HOLD); |
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| 138 | } |
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| 139 | |||
| 140 | #endif /* _LINUX_uPD4990A_H */ |