Jon Ringle | 0b83f14 | 2005-10-28 16:19:37 +0100 | [diff] [blame] | 1 | /*` |
| 2 | * mp1000-seprom.c |
| 3 | * |
| 4 | * This file contains the Serial EEPROM code for the MP1000 board |
| 5 | * |
| 6 | * Copyright (C) 2005 Comdial Corporation |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <asm/hardware.h> |
| 27 | #include <asm/hardware/clps7111.h> |
| 28 | #include <asm/arch/mp1000-seprom.h> |
| 29 | |
| 30 | /* If SepromInit() can initialize and checksum the seprom successfully, */ |
| 31 | /* then it will point seprom_data_ptr at the shadow copy. */ |
| 32 | |
| 33 | static eeprom_struct seprom_data; /* shadow copy of seprom content */ |
| 34 | |
| 35 | eeprom_struct *seprom_data_ptr = 0; /* 0 => not initialized */ |
| 36 | |
| 37 | /* |
| 38 | * Port D Bit 5 is Chip Select for EEPROM |
| 39 | * Port E Bit 0 is Input, Data out from EEPROM |
| 40 | * Port E Bit 1 is Output, Data in to EEPROM |
| 41 | * Port E Bit 2 is Output, CLK to EEPROM |
| 42 | */ |
| 43 | |
| 44 | static char *port_d_ptr = (char *)(CLPS7111_VIRT_BASE + PDDR); |
| 45 | static char *port_e_ptr = (char *)(CLPS7111_VIRT_BASE + PEDR); |
| 46 | |
| 47 | #define NO_OF_SHORTS 64 // Device is 64 x 16 bits |
| 48 | #define ENABLE_RW 0 |
| 49 | #define DISABLE_RW 1 |
| 50 | |
| 51 | static inline void toggle_seprom_clock(void) |
| 52 | { |
| 53 | *port_e_ptr |= HwPortESepromCLK; |
| 54 | *port_e_ptr &= ~(HwPortESepromCLK); |
| 55 | } |
| 56 | |
| 57 | static inline void select_eeprom(void) |
| 58 | { |
| 59 | *port_d_ptr |= HwPortDEECS; |
| 60 | *port_e_ptr &= ~(HwPortESepromCLK); |
| 61 | } |
| 62 | |
| 63 | static inline void deselect_eeprom(void) |
| 64 | { |
| 65 | *port_d_ptr &= ~(HwPortDEECS); |
| 66 | *port_e_ptr &= ~(HwPortESepromDIn); |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * GetSepromDataPtr - returns pointer to shadow (RAM) copy of seprom |
| 71 | * and returns 0 if seprom is not initialized or |
| 72 | * has a checksum error. |
| 73 | */ |
| 74 | |
| 75 | eeprom_struct* get_seprom_ptr(void) |
| 76 | { |
| 77 | return seprom_data_ptr; |
| 78 | } |
| 79 | |
| 80 | unsigned char* get_eeprom_mac_address(void) |
| 81 | { |
| 82 | return seprom_data_ptr->variant.eprom_struct.mac_Address; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * ReadSProm, Physically reads data from the Serial PROM |
| 87 | */ |
| 88 | static void read_sprom(short address, int length, eeprom_struct *buffer) |
| 89 | { |
| 90 | short data = COMMAND_READ | (address & 0x3F); |
| 91 | short bit; |
| 92 | int i; |
| 93 | |
| 94 | select_eeprom(); |
| 95 | |
| 96 | // Clock in 9 bits of the command |
| 97 | for (i = 0, bit = 0x100; i < 9; i++, bit >>= 1) { |
| 98 | if (data & bit) |
| 99 | *port_e_ptr |= HwPortESepromDIn; |
| 100 | else |
| 101 | *port_e_ptr &= ~(HwPortESepromDIn); |
| 102 | |
| 103 | toggle_seprom_clock(); |
| 104 | } |
| 105 | |
| 106 | // |
| 107 | // Now read one or more shorts of data from the Seprom |
| 108 | // |
| 109 | while (length-- > 0) { |
| 110 | data = 0; |
| 111 | |
| 112 | // Read 16 bits at a time |
| 113 | for (i = 0; i < 16; i++) { |
| 114 | data <<= 1; |
| 115 | toggle_seprom_clock(); |
| 116 | data |= *port_e_ptr & HwPortESepromDOut; |
| 117 | |
| 118 | } |
| 119 | |
| 120 | buffer->variant.eprom_short_data[address++] = data; |
| 121 | } |
| 122 | |
| 123 | deselect_eeprom(); |
| 124 | |
| 125 | return; |
| 126 | } |
| 127 | |
| 128 | |
| 129 | |
| 130 | /* |
| 131 | * ReadSerialPROM |
| 132 | * |
| 133 | * Input: Pointer to array of 64 x 16 Bits |
| 134 | * |
| 135 | * Output: if no problem reading data is filled in |
| 136 | */ |
| 137 | static void read_serial_prom(eeprom_struct *data) |
| 138 | { |
| 139 | read_sprom(0, 64, data); |
| 140 | } |
| 141 | |
| 142 | |
| 143 | // |
| 144 | // Compute Serial EEPROM checksum |
| 145 | // |
| 146 | // Input: Pointer to struct with Eprom data |
| 147 | // |
| 148 | // Output: The computed Eprom checksum |
| 149 | // |
| 150 | static short compute_seprom_checksum(eeprom_struct *data) |
| 151 | { |
| 152 | short checksum = 0; |
| 153 | int i; |
| 154 | |
| 155 | for (i = 0; i < 126; i++) { |
| 156 | checksum += (short)data->variant.eprom_byte_data[i]; |
| 157 | } |
| 158 | |
| 159 | return((short)(0x5555 - (checksum & 0xFFFF))); |
| 160 | } |
| 161 | |
| 162 | // |
| 163 | // Make sure the data port bits for the SEPROM are correctly initialised |
| 164 | // |
| 165 | |
| 166 | void __init seprom_init(void) |
| 167 | { |
| 168 | short checksum; |
| 169 | |
| 170 | // Init Port D |
| 171 | *(char *)(CLPS7111_VIRT_BASE + PDDDR) = 0x0; |
| 172 | *(char *)(CLPS7111_VIRT_BASE + PDDR) = 0x15; |
| 173 | |
| 174 | // Init Port E |
| 175 | *(int *)(CLPS7111_VIRT_BASE + PEDDR) = 0x06; |
| 176 | *(int *)(CLPS7111_VIRT_BASE + PEDR) = 0x04; |
| 177 | |
| 178 | // |
| 179 | // Make sure that EEPROM struct size never exceeds 128 bytes |
| 180 | // |
| 181 | if (sizeof(eeprom_struct) > 128) { |
| 182 | panic("Serial PROM struct size > 128, aborting read\n"); |
| 183 | } |
| 184 | |
| 185 | read_serial_prom(&seprom_data); |
| 186 | |
| 187 | checksum = compute_seprom_checksum(&seprom_data); |
| 188 | |
| 189 | if (checksum != seprom_data.variant.eprom_short_data[63]) { |
| 190 | panic("Serial EEPROM checksum failed\n"); |
| 191 | } |
| 192 | |
| 193 | seprom_data_ptr = &seprom_data; |
| 194 | } |
| 195 | |