Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of the coreboot project. |
| 3 | * |
| 4 | * Copyright (C) 2005 Yinghai Lu <yinghailu@gmail.com> |
| 5 | * Copyright (C) 2009 coresystems GmbH |
| 6 | * Copyright (C) 2013 Vladimir Serbinenko |
| 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; version 2 of the License. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | */ |
| 17 | |
| 18 | #include <arch/io.h> |
| 19 | #include <device/smbus_def.h> |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 20 | #include <stdlib.h> |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 21 | #include "smbus.h" |
| 22 | |
| 23 | |
| 24 | /* I801 command constants */ |
| 25 | #define I801_QUICK (0 << 2) |
| 26 | #define I801_BYTE (1 << 2) |
| 27 | #define I801_BYTE_DATA (2 << 2) |
| 28 | #define I801_WORD_DATA (3 << 2) |
| 29 | #define I801_BLOCK_DATA (5 << 2) |
| 30 | #define I801_I2C_BLOCK_DATA (6 << 2) /* ICH5 and later */ |
| 31 | |
| 32 | /* I801 Host Control register bits */ |
| 33 | #define SMBHSTCNT_INTREN (1 << 0) |
| 34 | #define SMBHSTCNT_KILL (1 << 1) |
| 35 | #define SMBHSTCNT_LAST_BYTE (1 << 5) |
| 36 | #define SMBHSTCNT_START (1 << 6) |
| 37 | #define SMBHSTCNT_PEC_EN (1 << 7) /* ICH3 and later */ |
| 38 | |
| 39 | /* I801 Hosts Status register bits */ |
| 40 | #define SMBHSTSTS_BYTE_DONE (1 << 7) |
| 41 | #define SMBHSTSTS_INUSE_STS (1 << 6) |
| 42 | #define SMBHSTSTS_SMBALERT_STS (1 << 5) |
| 43 | #define SMBHSTSTS_FAILED (1 << 4) |
| 44 | #define SMBHSTSTS_BUS_ERR (1 << 3) |
| 45 | #define SMBHSTSTS_DEV_ERR (1 << 2) |
| 46 | #define SMBHSTSTS_INTR (1 << 1) |
| 47 | #define SMBHSTSTS_HOST_BUSY (1 << 0) |
| 48 | |
| 49 | #define SMBUS_TIMEOUT (10 * 1000 * 100) |
Kyösti Mälkki | c17e855 | 2017-08-20 23:48:23 +0300 | [diff] [blame] | 50 | #define SMBUS_BLOCK_MAXLEN 32 |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 51 | |
| 52 | static void smbus_delay(void) |
| 53 | { |
| 54 | inb(0x80); |
| 55 | } |
| 56 | |
| 57 | static int smbus_wait_until_ready(u16 smbus_base) |
| 58 | { |
| 59 | unsigned int loops = SMBUS_TIMEOUT; |
| 60 | unsigned char byte; |
| 61 | do { |
| 62 | smbus_delay(); |
| 63 | if (--loops == 0) |
| 64 | break; |
| 65 | byte = inb(smbus_base + SMBHSTSTAT); |
| 66 | } while (byte & SMBHSTSTS_HOST_BUSY); |
| 67 | return loops ? 0 : -1; |
| 68 | } |
| 69 | |
| 70 | static int smbus_wait_until_done(u16 smbus_base) |
| 71 | { |
| 72 | unsigned int loops = SMBUS_TIMEOUT; |
| 73 | unsigned char byte; |
| 74 | do { |
| 75 | smbus_delay(); |
| 76 | if (--loops == 0) |
| 77 | break; |
| 78 | byte = inb(smbus_base + SMBHSTSTAT); |
| 79 | } while ((byte & SMBHSTSTS_HOST_BUSY) |
| 80 | || (byte & ~(SMBHSTSTS_INUSE_STS | SMBHSTSTS_HOST_BUSY)) == 0); |
| 81 | return loops ? 0 : -1; |
| 82 | } |
| 83 | |
| 84 | static int smbus_wait_until_active(u16 smbus_base) |
| 85 | { |
| 86 | unsigned long loops; |
| 87 | loops = SMBUS_TIMEOUT; |
| 88 | do { |
| 89 | unsigned char val; |
| 90 | smbus_delay(); |
| 91 | val = inb(smbus_base + SMBHSTSTAT); |
| 92 | if ((val & SMBHSTSTS_HOST_BUSY)) { |
| 93 | break; |
| 94 | } |
| 95 | } while (--loops); |
| 96 | return loops ? 0 : -1; |
| 97 | } |
| 98 | |
| 99 | int do_smbus_read_byte(unsigned int smbus_base, u8 device, |
| 100 | unsigned int address) |
| 101 | { |
| 102 | unsigned char status; |
| 103 | unsigned char byte; |
| 104 | |
| 105 | if (smbus_wait_until_ready(smbus_base) < 0) |
| 106 | return SMBUS_WAIT_UNTIL_READY_TIMEOUT; |
| 107 | /* Set up transaction */ |
| 108 | /* Disable interrupts */ |
| 109 | outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, |
| 110 | smbus_base + SMBHSTCTL); |
| 111 | /* Set the device I'm talking too */ |
| 112 | outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD); |
| 113 | /* Set the command/address... */ |
| 114 | outb(address & 0xff, smbus_base + SMBHSTCMD); |
| 115 | /* Set up for a byte data read */ |
| 116 | outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BYTE_DATA, |
| 117 | (smbus_base + SMBHSTCTL)); |
| 118 | /* Clear any lingering errors, so the transaction will run */ |
| 119 | outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| 120 | |
| 121 | /* Clear the data byte... */ |
| 122 | outb(0, smbus_base + SMBHSTDAT0); |
| 123 | |
| 124 | /* Start the command */ |
| 125 | outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| 126 | smbus_base + SMBHSTCTL); |
| 127 | |
| 128 | /* poll for it to start */ |
| 129 | if (smbus_wait_until_active(smbus_base) < 0) |
| 130 | return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT; |
| 131 | |
| 132 | /* Poll for transaction completion */ |
| 133 | if (smbus_wait_until_done(smbus_base) < 0) |
| 134 | return SMBUS_WAIT_UNTIL_DONE_TIMEOUT; |
| 135 | |
| 136 | status = inb(smbus_base + SMBHSTSTAT); |
| 137 | |
| 138 | /* Ignore the "In Use" status... */ |
| 139 | status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| 140 | |
| 141 | /* Read results of transaction */ |
| 142 | byte = inb(smbus_base + SMBHSTDAT0); |
| 143 | if (status != SMBHSTSTS_INTR) |
| 144 | return SMBUS_ERROR; |
| 145 | return byte; |
| 146 | } |
| 147 | |
| 148 | int do_smbus_write_byte(unsigned int smbus_base, u8 device, |
| 149 | unsigned int address, unsigned int data) |
| 150 | { |
| 151 | unsigned char status; |
| 152 | |
| 153 | if (smbus_wait_until_ready(smbus_base) < 0) |
| 154 | return SMBUS_WAIT_UNTIL_READY_TIMEOUT; |
| 155 | |
| 156 | /* Set up transaction */ |
| 157 | /* Disable interrupts */ |
| 158 | outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, |
| 159 | smbus_base + SMBHSTCTL); |
| 160 | /* Set the device I'm talking too */ |
| 161 | outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD); |
| 162 | /* Set the command/address... */ |
| 163 | outb(address & 0xff, smbus_base + SMBHSTCMD); |
| 164 | /* Set up for a byte data read */ |
| 165 | outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BYTE_DATA, |
| 166 | (smbus_base + SMBHSTCTL)); |
| 167 | /* Clear any lingering errors, so the transaction will run */ |
| 168 | outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| 169 | |
| 170 | /* Clear the data byte... */ |
| 171 | outb(data, smbus_base + SMBHSTDAT0); |
| 172 | |
| 173 | /* Start the command */ |
| 174 | outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| 175 | smbus_base + SMBHSTCTL); |
| 176 | |
| 177 | /* poll for it to start */ |
| 178 | if (smbus_wait_until_active(smbus_base) < 0) |
| 179 | return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT; |
| 180 | |
| 181 | /* Poll for transaction completion */ |
| 182 | if (smbus_wait_until_done(smbus_base) < 0) |
| 183 | return SMBUS_WAIT_UNTIL_DONE_TIMEOUT; |
| 184 | |
| 185 | status = inb(smbus_base + SMBHSTSTAT); |
| 186 | |
| 187 | /* Ignore the "In Use" status... */ |
| 188 | status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS); |
| 189 | |
| 190 | /* Read results of transaction */ |
| 191 | if (status != SMBHSTSTS_INTR) |
| 192 | return SMBUS_ERROR; |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd, |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 198 | unsigned int max_bytes, u8 *buf) |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 199 | { |
| 200 | u8 status; |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 201 | int slave_bytes; |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 202 | int bytes_read = 0; |
| 203 | unsigned int loops = SMBUS_TIMEOUT; |
| 204 | if (smbus_wait_until_ready(smbus_base) < 0) |
| 205 | return SMBUS_WAIT_UNTIL_READY_TIMEOUT; |
| 206 | |
Kyösti Mälkki | c17e855 | 2017-08-20 23:48:23 +0300 | [diff] [blame] | 207 | max_bytes = MIN(SMBUS_BLOCK_MAXLEN, max_bytes); |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 208 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 209 | /* Set up transaction */ |
| 210 | /* Disable interrupts */ |
| 211 | outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, |
| 212 | smbus_base + SMBHSTCTL); |
| 213 | /* Set the device I'm talking too */ |
| 214 | outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD); |
| 215 | /* Set the command/address... */ |
| 216 | outb(cmd & 0xff, smbus_base + SMBHSTCMD); |
| 217 | /* Set up for a block data read */ |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 218 | outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA, |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 219 | (smbus_base + SMBHSTCTL)); |
| 220 | /* Clear any lingering errors, so the transaction will run */ |
| 221 | outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| 222 | |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 223 | /* Reset number of bytes to transfer so we notice later it |
| 224 | * was really updated with the transaction. */ |
| 225 | outb(0, smbus_base + SMBHSTDAT0); |
| 226 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 227 | /* Start the command */ |
| 228 | outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| 229 | smbus_base + SMBHSTCTL); |
| 230 | |
| 231 | /* poll for it to start */ |
| 232 | if (smbus_wait_until_active(smbus_base) < 0) |
| 233 | return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT; |
| 234 | |
| 235 | /* Poll for transaction completion */ |
| 236 | do { |
| 237 | loops--; |
| 238 | status = inb(smbus_base + SMBHSTSTAT); |
| 239 | if (status & (SMBHSTSTS_FAILED | /* FAILED */ |
| 240 | SMBHSTSTS_BUS_ERR | /* BUS ERR */ |
| 241 | SMBHSTSTS_DEV_ERR)) /* DEV ERR */ |
| 242 | return SMBUS_ERROR; |
| 243 | |
| 244 | if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */ |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 245 | |
| 246 | if (bytes_read < max_bytes) { |
Kyösti Mälkki | c17e855 | 2017-08-20 23:48:23 +0300 | [diff] [blame] | 247 | *buf++ = inb(smbus_base + SMBBLKDAT); |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 248 | bytes_read++; |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 249 | } |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 250 | |
| 251 | /* Engine internally completes the transaction |
| 252 | * and clears HOST_BUSY flag once the byte count |
| 253 | * from slave is reached. |
| 254 | */ |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 255 | outb(status, smbus_base + SMBHSTSTAT); |
| 256 | } |
| 257 | } while ((status & SMBHSTSTS_HOST_BUSY) && loops); |
| 258 | |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 259 | /* Post-check we received complete message. */ |
| 260 | slave_bytes = inb(smbus_base + SMBHSTDAT0); |
| 261 | if (bytes_read < slave_bytes) |
| 262 | return SMBUS_ERROR; |
| 263 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 264 | return bytes_read; |
| 265 | } |
| 266 | |
| 267 | int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd, |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 268 | const unsigned int bytes, const u8 *buf) |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 269 | { |
| 270 | u8 status; |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 271 | int bytes_sent = 0; |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 272 | unsigned int loops = SMBUS_TIMEOUT; |
| 273 | |
Kyösti Mälkki | c17e855 | 2017-08-20 23:48:23 +0300 | [diff] [blame] | 274 | if (bytes > SMBUS_BLOCK_MAXLEN) |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 275 | return SMBUS_ERROR; |
| 276 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 277 | if (smbus_wait_until_ready(smbus_base) < 0) |
| 278 | return SMBUS_WAIT_UNTIL_READY_TIMEOUT; |
| 279 | |
| 280 | /* Set up transaction */ |
| 281 | /* Disable interrupts */ |
| 282 | outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, |
| 283 | smbus_base + SMBHSTCTL); |
| 284 | /* Set the device I'm talking too */ |
| 285 | outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD); |
| 286 | /* Set the command/address... */ |
| 287 | outb(cmd & 0xff, smbus_base + SMBHSTCMD); |
| 288 | /* Set up for a block data write */ |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 289 | outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA, |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 290 | (smbus_base + SMBHSTCTL)); |
| 291 | /* Clear any lingering errors, so the transaction will run */ |
| 292 | outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| 293 | |
| 294 | /* set number of bytes to transfer */ |
| 295 | outb(bytes, smbus_base + SMBHSTDAT0); |
| 296 | |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 297 | /* Send first byte from buffer, bytes_sent increments after |
| 298 | * hardware acknowledges it. |
| 299 | */ |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 300 | outb(*buf++, smbus_base + SMBBLKDAT); |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 301 | |
| 302 | /* Start the command */ |
| 303 | outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| 304 | smbus_base + SMBHSTCTL); |
| 305 | |
| 306 | /* poll for it to start */ |
| 307 | if (smbus_wait_until_active(smbus_base) < 0) |
| 308 | return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT; |
| 309 | |
| 310 | /* Poll for transaction completion */ |
| 311 | do { |
| 312 | loops--; |
| 313 | status = inb(smbus_base + SMBHSTSTAT); |
| 314 | if (status & (SMBHSTSTS_FAILED | /* FAILED */ |
| 315 | SMBHSTSTS_BUS_ERR | /* BUS ERR */ |
| 316 | SMBHSTSTS_DEV_ERR)) /* DEV ERR */ |
| 317 | return SMBUS_ERROR; |
| 318 | |
| 319 | if (status & SMBHSTSTS_BYTE_DONE) { |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 320 | bytes_sent++; |
| 321 | if (bytes_sent < bytes) |
| 322 | outb(*buf++, smbus_base + SMBBLKDAT); |
| 323 | |
| 324 | /* Engine internally completes the transaction |
| 325 | * and clears HOST_BUSY flag once the byte count |
| 326 | * has been reached. |
| 327 | */ |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 328 | outb(status, smbus_base + SMBHSTSTAT); |
| 329 | } |
| 330 | } while ((status & SMBHSTSTS_HOST_BUSY) && loops); |
| 331 | |
Kyösti Mälkki | c17e855 | 2017-08-20 23:48:23 +0300 | [diff] [blame] | 332 | if (bytes_sent < bytes) |
| 333 | return SMBUS_ERROR; |
| 334 | |
Arthur Heymans | 1b04aa2 | 2017-08-04 14:28:50 +0200 | [diff] [blame] | 335 | return bytes_sent; |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 336 | } |
| 337 | |
| 338 | /* Only since ICH5 */ |
| 339 | int do_i2c_block_read(unsigned int smbus_base, u8 device, |
Kyösti Mälkki | 1e39236 | 2017-08-20 21:36:03 +0300 | [diff] [blame^] | 340 | unsigned int offset, const unsigned int bytes, u8 *buf) |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 341 | { |
| 342 | u8 status; |
| 343 | int bytes_read = 0; |
| 344 | unsigned int loops = SMBUS_TIMEOUT; |
| 345 | if (smbus_wait_until_ready(smbus_base) < 0) |
| 346 | return SMBUS_WAIT_UNTIL_READY_TIMEOUT; |
| 347 | |
| 348 | /* Set upp transaction */ |
| 349 | /* Disable interrupts */ |
| 350 | outb(inb(smbus_base + SMBHSTCTL) & SMBHSTCNT_INTREN, |
| 351 | smbus_base + SMBHSTCTL); |
| 352 | /* Set the device I'm talking to */ |
| 353 | outb((device & 0x7f) << 1, smbus_base + SMBXMITADD); |
| 354 | |
| 355 | /* device offset */ |
| 356 | outb(offset, smbus_base + SMBHSTDAT1); |
| 357 | |
| 358 | /* Set up for a i2c block data read */ |
| 359 | outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_I2C_BLOCK_DATA, |
| 360 | (smbus_base + SMBHSTCTL)); |
| 361 | |
| 362 | /* Clear any lingering errors, so the transaction will run */ |
| 363 | outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT); |
| 364 | /* Start the command */ |
| 365 | outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START), |
| 366 | smbus_base + SMBHSTCTL); |
| 367 | |
| 368 | /* poll for it to start */ |
| 369 | if (smbus_wait_until_active(smbus_base) < 0) |
| 370 | return SMBUS_WAIT_UNTIL_ACTIVE_TIMEOUT; |
| 371 | |
| 372 | /* Poll for transaction completion */ |
| 373 | do { |
| 374 | loops--; |
| 375 | status = inb(smbus_base + SMBHSTSTAT); |
| 376 | if (status & (SMBHSTSTS_FAILED | /* FAILED */ |
| 377 | SMBHSTSTS_BUS_ERR | /* BUS ERR */ |
| 378 | SMBHSTSTS_DEV_ERR)) /* DEV ERR */ |
| 379 | return SMBUS_ERROR; |
| 380 | |
| 381 | if (status & SMBHSTSTS_BYTE_DONE) { |
Kyösti Mälkki | 1e39236 | 2017-08-20 21:36:03 +0300 | [diff] [blame^] | 382 | |
| 383 | if (bytes_read < bytes) { |
| 384 | *buf++ = inb(smbus_base + SMBBLKDAT); |
| 385 | bytes_read++; |
| 386 | } |
| 387 | |
| 388 | if (bytes_read + 1 >= bytes) { |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 389 | /* indicate that next byte is the last one */ |
| 390 | outb(inb(smbus_base + SMBHSTCTL) |
| 391 | | SMBHSTCNT_LAST_BYTE, |
| 392 | smbus_base + SMBHSTCTL); |
| 393 | } |
Kyösti Mälkki | 1e39236 | 2017-08-20 21:36:03 +0300 | [diff] [blame^] | 394 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 395 | outb(status, smbus_base + SMBHSTSTAT); |
| 396 | } |
| 397 | } while ((status & SMBHSTSTS_HOST_BUSY) && loops); |
| 398 | |
Kyösti Mälkki | 1e39236 | 2017-08-20 21:36:03 +0300 | [diff] [blame^] | 399 | if (bytes_read < bytes) |
| 400 | return SMBUS_ERROR; |
| 401 | |
Arthur Heymans | 16fe790 | 2017-04-12 17:01:31 +0200 | [diff] [blame] | 402 | return bytes_read; |
| 403 | } |