[e56c3546] | 1 | /* |
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| 2 | * DS1307-based Non-Volatile memory device driver |
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| 3 | * |
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| 4 | * DS1307 chip is a I2C Real-Time Clock. It contains 56 bytes of |
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| 5 | * non-volatile RAM storage. This driver provide file-like interface to |
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| 6 | * this memory. |
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| 7 | * |
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| 8 | * Copyright (C) 2000 OKTET Ltd., St.-Petersburg, Russia |
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| 9 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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| 10 | * |
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| 11 | * The license and distribution terms for this file may be |
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| 12 | * found in the file LICENSE in this distribution or at |
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| 13 | * |
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[acaae90] | 14 | * http://www.rtems.com/license/LICENSE. |
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[e56c3546] | 15 | * |
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| 16 | * @(#) $Id$ |
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| 17 | */ |
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| 18 | |
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| 19 | #include <rtems.h> |
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| 20 | #include <rtems/libio.h> |
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| 21 | #include <errno.h> |
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[1625856] | 22 | #include <string.h> |
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[e56c3546] | 23 | #include <bsp.h> |
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| 24 | #include <nvram.h> |
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| 25 | #include <i2c.h> |
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| 26 | #include <ds1307.h> |
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| 27 | |
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| 28 | |
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| 29 | /* nvram_driver_initialize -- |
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| 30 | * Non-volatile memory device driver initialization. |
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| 31 | */ |
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| 32 | rtems_device_driver |
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| 33 | nvram_driver_initialize(rtems_device_major_number major, |
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| 34 | rtems_device_minor_number minor, |
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| 35 | void *arg) |
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| 36 | { |
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| 37 | rtems_status_code sc; |
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| 38 | i2c_message_status status; |
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| 39 | i2c_bus_number bus = DS1307_I2C_BUS_NUMBER; |
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| 40 | i2c_address addr = DS1307_I2C_ADDRESS; |
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| 41 | int try = 0; |
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| 42 | do { |
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| 43 | status = i2c_wrbyte(bus, addr, 0); |
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| 44 | if (status == I2C_NO_DEVICE) |
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| 45 | break; |
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| 46 | try++; |
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| 47 | } while ((try < 15) && (status != I2C_SUCCESSFUL)); |
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| 48 | |
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| 49 | if (status == I2C_SUCCESSFUL) |
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| 50 | { |
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| 51 | sc = rtems_io_register_name("/dev/nvram", major, 0); |
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| 52 | if (sc != RTEMS_SUCCESSFUL) |
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| 53 | { |
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| 54 | errno = EIO; |
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| 55 | return RTEMS_UNSATISFIED; |
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| 56 | } |
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| 57 | else |
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| 58 | return RTEMS_SUCCESSFUL; |
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| 59 | } |
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| 60 | else |
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| 61 | { |
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| 62 | errno = ENODEV; |
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| 63 | return RTEMS_UNSATISFIED; |
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| 64 | } |
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| 65 | } |
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| 66 | |
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| 67 | /* nvram_driver_open -- |
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| 68 | * Non-volatile memory device driver open primitive. |
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| 69 | */ |
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| 70 | rtems_device_driver |
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| 71 | nvram_driver_open(rtems_device_major_number major, |
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| 72 | rtems_device_minor_number minor, |
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| 73 | void *arg) |
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| 74 | { |
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| 75 | return RTEMS_SUCCESSFUL; |
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| 76 | } |
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| 77 | |
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| 78 | /* nvram_driver_close -- |
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| 79 | * Non-volatile memory device driver close primitive. |
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| 80 | */ |
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| 81 | rtems_device_driver |
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| 82 | nvram_driver_close(rtems_device_major_number major, |
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| 83 | rtems_device_minor_number minor, |
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| 84 | void *arg) |
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| 85 | { |
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| 86 | return RTEMS_SUCCESSFUL; |
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| 87 | } |
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| 88 | |
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| 89 | /* nvram_driver_read -- |
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| 90 | * Non-volatile memory device driver read primitive. |
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| 91 | */ |
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| 92 | rtems_device_driver |
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| 93 | nvram_driver_read(rtems_device_major_number major, |
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| 94 | rtems_device_minor_number minor, |
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| 95 | void *arg) |
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| 96 | { |
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| 97 | rtems_libio_rw_args_t *args = arg; |
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| 98 | unsigned32 count; |
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| 99 | i2c_bus_number bus = DS1307_I2C_BUS_NUMBER; |
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| 100 | i2c_address addr = DS1307_I2C_ADDRESS; |
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| 101 | i2c_message_status status; |
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| 102 | if (args->offset >= DS1307_NVRAM_SIZE) |
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| 103 | { |
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| 104 | count = 0; |
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| 105 | } |
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| 106 | else if (args->offset + args->count >= DS1307_NVRAM_SIZE) |
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| 107 | { |
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| 108 | count = DS1307_NVRAM_SIZE - args->offset; |
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| 109 | } |
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| 110 | else |
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| 111 | { |
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| 112 | count = args->count; |
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| 113 | } |
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| 114 | if (count > 0) |
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| 115 | { |
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| 116 | int try = 0; |
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| 117 | do { |
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| 118 | status = i2c_wbrd(bus, addr, DS1307_NVRAM_START + args->offset, |
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| 119 | args->buffer, count); |
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| 120 | try++; |
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| 121 | } while ((try < 15) && (status != I2C_SUCCESSFUL)); |
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| 122 | if (status != I2C_SUCCESSFUL) |
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| 123 | { |
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| 124 | errno = EIO; |
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| 125 | return RTEMS_UNSATISFIED; |
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| 126 | } |
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| 127 | } |
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| 128 | args->bytes_moved = count; |
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| 129 | return RTEMS_SUCCESSFUL; |
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| 130 | } |
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| 131 | |
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| 132 | /* nvram_driver_write -- |
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| 133 | * Non-volatile memory device driver write primitive. |
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| 134 | */ |
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| 135 | rtems_device_driver |
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| 136 | nvram_driver_write(rtems_device_major_number major, |
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| 137 | rtems_device_minor_number minor, |
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| 138 | void *arg) |
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| 139 | { |
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| 140 | rtems_libio_rw_args_t *args = arg; |
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| 141 | unsigned32 count; |
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| 142 | i2c_bus_number bus = DS1307_I2C_BUS_NUMBER; |
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| 143 | i2c_address addr = DS1307_I2C_ADDRESS; |
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| 144 | i2c_message_status status; |
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| 145 | |
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| 146 | if (args->offset >= DS1307_NVRAM_SIZE) |
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| 147 | { |
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| 148 | count = 0; |
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| 149 | } |
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| 150 | else if (args->offset + args->count >= DS1307_NVRAM_SIZE) |
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| 151 | { |
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| 152 | count = DS1307_NVRAM_SIZE - args->offset; |
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| 153 | } |
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| 154 | else |
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| 155 | { |
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| 156 | count = args->count; |
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| 157 | } |
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| 158 | if (count > 0) |
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| 159 | { |
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| 160 | int try = 0; |
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| 161 | do { |
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| 162 | rtems_unsigned8 buf[DS1307_NVRAM_SIZE + 1]; |
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| 163 | buf[0] = DS1307_NVRAM_START + args->offset; |
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| 164 | memcpy(buf+1, args->buffer, count); |
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| 165 | status = i2c_write(bus, addr, buf, count+1); |
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| 166 | try++; |
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| 167 | } while ((try < 15) && (status != I2C_SUCCESSFUL)); |
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| 168 | if (status != I2C_SUCCESSFUL) |
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| 169 | { |
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| 170 | errno = EIO; |
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| 171 | return RTEMS_UNSATISFIED; |
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| 172 | } |
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| 173 | } |
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| 174 | args->bytes_moved = count; |
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| 175 | return RTEMS_SUCCESSFUL; |
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| 176 | } |
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