Ivo van Doorn | 9467d64 | 2007-05-11 15:59:40 -0400 | [diff] [blame] | 1 | /* |
| 2 | Copyright (C) 2004 - 2006 rt2x00 SourceForge Project |
| 3 | <http://rt2x00.serialmonkey.com> |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 2 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the |
| 17 | Free Software Foundation, Inc., |
| 18 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 19 | */ |
| 20 | |
| 21 | /* |
| 22 | Module: eeprom_93cx6 |
| 23 | Abstract: EEPROM reader routines for 93cx6 chipsets. |
| 24 | Supported chipsets: 93c46 & 93c66. |
| 25 | */ |
| 26 | |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/version.h> |
| 30 | #include <linux/delay.h> |
| 31 | #include <linux/eeprom_93cx6.h> |
| 32 | |
| 33 | MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); |
| 34 | MODULE_VERSION("1.0"); |
| 35 | MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); |
| 36 | MODULE_LICENSE("GPL"); |
| 37 | |
| 38 | static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) |
| 39 | { |
| 40 | eeprom->reg_data_clock = 1; |
| 41 | eeprom->register_write(eeprom); |
Ivo van Doorn | 4b914dc | 2007-05-14 23:06:01 +0200 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * Add a short delay for the pulse to work. |
John W. Linville | 7e9400f | 2007-06-11 21:37:46 -0400 | [diff] [blame^] | 45 | * According to the specifications the "maximum minimum" |
| 46 | * time should be 450ns. |
Ivo van Doorn | 4b914dc | 2007-05-14 23:06:01 +0200 | [diff] [blame] | 47 | */ |
John W. Linville | 7e9400f | 2007-06-11 21:37:46 -0400 | [diff] [blame^] | 48 | ndelay(450); |
Ivo van Doorn | 9467d64 | 2007-05-11 15:59:40 -0400 | [diff] [blame] | 49 | } |
| 50 | |
| 51 | static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) |
| 52 | { |
| 53 | eeprom->reg_data_clock = 0; |
| 54 | eeprom->register_write(eeprom); |
Ivo van Doorn | 4b914dc | 2007-05-14 23:06:01 +0200 | [diff] [blame] | 55 | |
| 56 | /* |
| 57 | * Add a short delay for the pulse to work. |
| 58 | * According to the specifications the minimal time |
| 59 | * should be 450ns so a 1us delay is sufficient. |
| 60 | */ |
Ivo van Doorn | 9467d64 | 2007-05-11 15:59:40 -0400 | [diff] [blame] | 61 | udelay(1); |
| 62 | } |
| 63 | |
| 64 | static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) |
| 65 | { |
| 66 | /* |
| 67 | * Clear all flags, and enable chip select. |
| 68 | */ |
| 69 | eeprom->register_read(eeprom); |
| 70 | eeprom->reg_data_in = 0; |
| 71 | eeprom->reg_data_out = 0; |
| 72 | eeprom->reg_data_clock = 0; |
| 73 | eeprom->reg_chip_select = 1; |
| 74 | eeprom->register_write(eeprom); |
| 75 | |
| 76 | /* |
| 77 | * kick a pulse. |
| 78 | */ |
| 79 | eeprom_93cx6_pulse_high(eeprom); |
| 80 | eeprom_93cx6_pulse_low(eeprom); |
| 81 | } |
| 82 | |
| 83 | static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) |
| 84 | { |
| 85 | /* |
| 86 | * Clear chip_select and data_in flags. |
| 87 | */ |
| 88 | eeprom->register_read(eeprom); |
| 89 | eeprom->reg_data_in = 0; |
| 90 | eeprom->reg_chip_select = 0; |
| 91 | eeprom->register_write(eeprom); |
| 92 | |
| 93 | /* |
| 94 | * kick a pulse. |
| 95 | */ |
| 96 | eeprom_93cx6_pulse_high(eeprom); |
| 97 | eeprom_93cx6_pulse_low(eeprom); |
| 98 | } |
| 99 | |
| 100 | static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, |
| 101 | const u16 data, const u16 count) |
| 102 | { |
| 103 | unsigned int i; |
| 104 | |
| 105 | eeprom->register_read(eeprom); |
| 106 | |
| 107 | /* |
| 108 | * Clear data flags. |
| 109 | */ |
| 110 | eeprom->reg_data_in = 0; |
| 111 | eeprom->reg_data_out = 0; |
| 112 | |
| 113 | /* |
| 114 | * Start writing all bits. |
| 115 | */ |
| 116 | for (i = count; i > 0; i--) { |
| 117 | /* |
| 118 | * Check if this bit needs to be set. |
| 119 | */ |
| 120 | eeprom->reg_data_in = !!(data & (1 << (i - 1))); |
| 121 | |
| 122 | /* |
| 123 | * Write the bit to the eeprom register. |
| 124 | */ |
| 125 | eeprom->register_write(eeprom); |
| 126 | |
| 127 | /* |
| 128 | * Kick a pulse. |
| 129 | */ |
| 130 | eeprom_93cx6_pulse_high(eeprom); |
| 131 | eeprom_93cx6_pulse_low(eeprom); |
| 132 | } |
| 133 | |
| 134 | eeprom->reg_data_in = 0; |
| 135 | eeprom->register_write(eeprom); |
| 136 | } |
| 137 | |
| 138 | static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, |
| 139 | u16 *data, const u16 count) |
| 140 | { |
| 141 | unsigned int i; |
| 142 | u16 buf = 0; |
| 143 | |
| 144 | eeprom->register_read(eeprom); |
| 145 | |
| 146 | /* |
| 147 | * Clear data flags. |
| 148 | */ |
| 149 | eeprom->reg_data_in = 0; |
| 150 | eeprom->reg_data_out = 0; |
| 151 | |
| 152 | /* |
| 153 | * Start reading all bits. |
| 154 | */ |
| 155 | for (i = count; i > 0; i--) { |
| 156 | eeprom_93cx6_pulse_high(eeprom); |
| 157 | |
| 158 | eeprom->register_read(eeprom); |
| 159 | |
| 160 | /* |
| 161 | * Clear data_in flag. |
| 162 | */ |
| 163 | eeprom->reg_data_in = 0; |
| 164 | |
| 165 | /* |
| 166 | * Read if the bit has been set. |
| 167 | */ |
| 168 | if (eeprom->reg_data_out) |
| 169 | buf |= (1 << (i - 1)); |
| 170 | |
| 171 | eeprom_93cx6_pulse_low(eeprom); |
| 172 | } |
| 173 | |
| 174 | *data = buf; |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * eeprom_93cx6_read - Read multiple words from eeprom |
| 179 | * @eeprom: Pointer to eeprom structure |
| 180 | * @word: Word index from where we should start reading |
| 181 | * @data: target pointer where the information will have to be stored |
| 182 | * |
| 183 | * This function will read the eeprom data as host-endian word |
| 184 | * into the given data pointer. |
| 185 | */ |
| 186 | void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, |
| 187 | u16 *data) |
| 188 | { |
| 189 | u16 command; |
| 190 | |
| 191 | /* |
| 192 | * Initialize the eeprom register |
| 193 | */ |
| 194 | eeprom_93cx6_startup(eeprom); |
| 195 | |
| 196 | /* |
| 197 | * Select the read opcode and the word to be read. |
| 198 | */ |
| 199 | command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; |
| 200 | eeprom_93cx6_write_bits(eeprom, command, |
| 201 | PCI_EEPROM_WIDTH_OPCODE + eeprom->width); |
| 202 | |
| 203 | /* |
| 204 | * Read the requested 16 bits. |
| 205 | */ |
| 206 | eeprom_93cx6_read_bits(eeprom, data, 16); |
| 207 | |
| 208 | /* |
| 209 | * Cleanup eeprom register. |
| 210 | */ |
| 211 | eeprom_93cx6_cleanup(eeprom); |
| 212 | } |
| 213 | EXPORT_SYMBOL_GPL(eeprom_93cx6_read); |
| 214 | |
| 215 | /** |
| 216 | * eeprom_93cx6_multiread - Read multiple words from eeprom |
| 217 | * @eeprom: Pointer to eeprom structure |
| 218 | * @word: Word index from where we should start reading |
| 219 | * @data: target pointer where the information will have to be stored |
| 220 | * @words: Number of words that should be read. |
| 221 | * |
| 222 | * This function will read all requested words from the eeprom, |
| 223 | * this is done by calling eeprom_93cx6_read() multiple times. |
| 224 | * But with the additional change that while the eeprom_93cx6_read |
| 225 | * will return host ordered bytes, this method will return little |
| 226 | * endian words. |
| 227 | */ |
| 228 | void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, |
| 229 | __le16 *data, const u16 words) |
| 230 | { |
| 231 | unsigned int i; |
| 232 | u16 tmp; |
| 233 | |
| 234 | for (i = 0; i < words; i++) { |
| 235 | tmp = 0; |
| 236 | eeprom_93cx6_read(eeprom, word + i, &tmp); |
| 237 | data[i] = cpu_to_le16(tmp); |
| 238 | } |
| 239 | } |
| 240 | EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); |
| 241 | |