Travis Geiselbrecht | bea5a4a | 2008-09-06 01:32:02 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2008 Travis Geiselbrecht |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <debug.h> |
| 24 | #include <err.h> |
| 25 | #include <reg.h> |
| 26 | #include <string.h> |
| 27 | #include <platform.h> |
| 28 | #include <platform/omap3.h> |
| 29 | |
| 30 | #define LOCAL_TRACE 0 |
| 31 | |
| 32 | #define I2C_TIMEOUT 200 |
| 33 | |
| 34 | static const addr_t i2c_reg_base[] = { |
| 35 | I2C1_BASE, |
| 36 | I2C2_BASE, |
| 37 | I2C3_BASE, |
| 38 | }; |
| 39 | |
| 40 | #define I2C_REG_ADDR(bus, reg) (i2c_reg_base[bus] + (reg)) |
| 41 | #define I2C_REG(bus, reg) (*REG16(I2C_REG_ADDR(bus, reg))) |
| 42 | #define I2C_RMW_REG(bus, reg, startbit, width, val) RMWREG16(I2C_REG_ADDR(bus, reg), startbit, width, val) |
| 43 | |
| 44 | static void i2c_dump_bus(int bus) |
| 45 | { |
| 46 | hexdump((void *)i2c_reg_base[bus], 128); |
| 47 | } |
| 48 | |
| 49 | static void i2c_reset_bus(int bus) |
| 50 | { |
| 51 | I2C_REG(bus, I2C_CON) &= ~(1<<15); // make sure the bus is disabled |
| 52 | |
| 53 | /* reset the bus */ |
| 54 | I2C_REG(bus, I2C_SYSC) = (1<<1); |
| 55 | I2C_REG(bus, I2C_CON) = (1<<15); // enable the bus |
| 56 | while ((I2C_REG(bus, I2C_SYSS) & 1) == 0) |
| 57 | ; |
| 58 | |
| 59 | /* disable the bus again and set up some internals */ |
| 60 | I2C_REG(bus, I2C_CON) &= ~(1<<15); // make sure the bus is disabled |
| 61 | |
| 62 | /* set up the clock */ |
| 63 | I2C_REG(bus, I2C_PSC) = 23; // 96Mhz / 23 == 4Mhz |
| 64 | I2C_REG(bus, I2C_SCLL) = 13; |
| 65 | I2C_REG(bus, I2C_SCLH) = 15; // 4Mhz / combined divider of 40 (13+7 + 15+5) == 100khz |
| 66 | |
| 67 | /* slave address */ |
| 68 | I2C_REG(bus, I2C_OA0) = 1; // XXX made this up |
| 69 | |
| 70 | /* fifo is set to 1 byte trigger */ |
| 71 | I2C_REG(bus, I2C_BUF) = 0; |
| 72 | |
| 73 | /* disable all interrupts */ |
| 74 | I2C_REG(bus, I2C_IE) = 0; |
| 75 | |
| 76 | /* enable the bus */ |
| 77 | I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<9); // enable, master, transmitter mode |
| 78 | } |
| 79 | |
| 80 | static void i2c_wait_for_bb(int bus) |
| 81 | { |
| 82 | I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| 83 | while (I2C_REG(bus, I2C_STAT) & (1<<12)) { |
| 84 | I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| 85 | } |
| 86 | I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| 87 | } |
| 88 | |
| 89 | int i2c_transmit(int bus, uint8_t address, const void *buf, size_t count) |
| 90 | { |
| 91 | int err; |
| 92 | |
| 93 | LTRACEF("bus %d, address 0x%hhx, buf %p, count %zd\n", bus, address, buf, count); |
| 94 | |
| 95 | i2c_wait_for_bb(bus); |
| 96 | |
| 97 | I2C_REG(bus, I2C_SA) = address; |
| 98 | I2C_REG(bus, I2C_CNT) = count; |
| 99 | I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<9)|(1<<1)|(1<<0); // enable, master, transmit, STP, STT |
| 100 | |
| 101 | time_t t = current_time(); |
| 102 | |
| 103 | const uint8_t *ptr = (const uint8_t *)buf; |
| 104 | for(;;) { |
| 105 | uint16_t stat = I2C_REG(bus, I2C_STAT); |
| 106 | if (stat & (1<<1)) { |
| 107 | // NACK |
| 108 | // printf("NACK\n"); |
| 109 | err = -1; |
| 110 | goto out; |
| 111 | } |
| 112 | if (stat & (1<<0)) { |
| 113 | // AL (arbitration lost) |
| 114 | // printf("arbitration lost!\n"); |
| 115 | err = -1; |
| 116 | goto out; |
| 117 | } |
| 118 | if (stat & (1<<2)) { |
| 119 | // ARDY |
| 120 | // printf("ARDY, completed\n"); |
| 121 | break; |
| 122 | } |
| 123 | if (stat & (1<<4)) { |
| 124 | // RRDY |
| 125 | // printf("XRDY\n"); |
| 126 | |
| 127 | // transmit a byte |
| 128 | *REG8(I2C_REG_ADDR(bus, I2C_DATA)) = *ptr; |
| 129 | ptr++; |
| 130 | } |
| 131 | I2C_REG(bus, I2C_STAT) = stat; |
| 132 | |
| 133 | if (current_time() - t > I2C_TIMEOUT) { |
| 134 | // printf("i2c timeout\n"); |
| 135 | err = ERR_TIMED_OUT; |
| 136 | goto out; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | err = 0; |
| 141 | |
| 142 | out: |
| 143 | I2C_REG(bus, I2C_STAT) = 0xffff; |
| 144 | I2C_REG(bus, I2C_CNT) = 0; |
| 145 | |
| 146 | return err; |
| 147 | } |
| 148 | |
| 149 | int i2c_receive(int bus, uint8_t address, void *buf, size_t count) |
| 150 | { |
| 151 | int err; |
| 152 | |
| 153 | LTRACEF("bus %d, address 0x%hhx, buf %p, count %zd\n", bus, address, buf, count); |
| 154 | |
| 155 | i2c_wait_for_bb(bus); |
| 156 | |
| 157 | I2C_REG(bus, I2C_SA) = address; |
| 158 | I2C_REG(bus, I2C_CNT) = count; |
| 159 | I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<1)|(1<<0); // enable, master, STP, STT |
| 160 | |
| 161 | time_t t = current_time(); |
| 162 | |
| 163 | uint8_t *ptr = (uint8_t *)buf; |
| 164 | for(;;) { |
| 165 | uint16_t stat = I2C_REG(bus, I2C_STAT); |
| 166 | if (stat & (1<<1)) { |
| 167 | // NACK |
| 168 | // printf("NACK\n"); |
| 169 | err = -1; |
| 170 | goto out; |
| 171 | } |
| 172 | if (stat & (1<<0)) { |
| 173 | // AL (arbitration lost) |
| 174 | // printf("arbitration lost!\n"); |
| 175 | err = -1; |
| 176 | goto out; |
| 177 | } |
| 178 | if (stat & (1<<2)) { |
| 179 | // ARDY |
| 180 | // printf("ARDY, completed\n"); |
| 181 | break; |
| 182 | } |
| 183 | if (stat & (1<<3)) { |
| 184 | // RRDY |
| 185 | // printf("RRDY\n"); |
| 186 | |
| 187 | // read a byte, since our fifo threshold is set to 1 byte |
| 188 | *ptr = *REG8(I2C_REG_ADDR(bus, I2C_DATA)); |
| 189 | ptr++; |
| 190 | } |
| 191 | I2C_REG(bus, I2C_STAT) = stat; |
| 192 | |
| 193 | if (current_time() - t > I2C_TIMEOUT) { |
| 194 | // printf("i2c timeout\n"); |
| 195 | err = ERR_TIMED_OUT; |
| 196 | goto out; |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | err = 0; |
| 201 | |
| 202 | out: |
| 203 | I2C_REG(bus, I2C_STAT) = 0xffff; |
| 204 | I2C_REG(bus, I2C_CNT) = 0; |
| 205 | |
| 206 | return err; |
| 207 | } |
| 208 | |
| 209 | int i2c_write_reg(int bus, uint8_t address, uint8_t reg, uint8_t val) |
| 210 | { |
| 211 | uint8_t buf[2]; |
| 212 | |
| 213 | buf[0] = reg; |
| 214 | buf[1] = val; |
| 215 | |
| 216 | return i2c_transmit(bus, address, buf, 2); |
| 217 | } |
| 218 | |
| 219 | int i2c_read_reg(int bus, uint8_t address, uint8_t reg, uint8_t *val) |
| 220 | { |
| 221 | int err = i2c_transmit(bus, address, ®, 1); |
| 222 | if (err < 0) |
| 223 | return err; |
| 224 | |
| 225 | return i2c_receive(bus, address, val, 1); |
| 226 | } |
| 227 | |
| 228 | |
| 229 | void i2c_init_early(void) |
| 230 | { |
| 231 | LTRACE_ENTRY; |
| 232 | |
Travis Geiselbrecht | 2c691e8 | 2008-09-04 02:41:01 -0700 | [diff] [blame] | 233 | /* enable clocks on i2c 0-2 */ |
| 234 | RMWREG32(CM_FCLKEN1_CORE, 15, 3, 0x7), |
| 235 | RMWREG32(CM_ICLKEN1_CORE, 15, 3, 0x7), |
| 236 | |
Travis Geiselbrecht | bea5a4a | 2008-09-06 01:32:02 -0700 | [diff] [blame] | 237 | i2c_reset_bus(0); |
| 238 | i2c_reset_bus(1); |
| 239 | i2c_reset_bus(2); |
| 240 | |
| 241 | #if 0 |
| 242 | // write something into a reg |
| 243 | char buf[2]; |
| 244 | i2c_write_reg(0, 0x4b, 0x14, 0x99); |
| 245 | i2c_write_reg(0, 0x4b, 0x15, 0x98); |
| 246 | |
| 247 | i2c_read_reg(0, 0x4b, 0x15, buf); |
| 248 | printf("0x%hhx\n", buf[0]); |
| 249 | i2c_read_reg(0, 0x4b, 0x14, buf); |
| 250 | printf("0x%hhx\n", buf[0]); |
| 251 | |
| 252 | int i; |
| 253 | for (i=0; i < 255; i++) { |
| 254 | char buf[1]; |
| 255 | buf[0] = i; |
| 256 | i2c_transmit(0, 0x4b, buf, 1); |
| 257 | i2c_receive(0, 0x4b, buf, sizeof(buf)); |
| 258 | printf("0x%hhx\n", buf[0]); |
| 259 | } |
| 260 | #endif |
| 261 | |
| 262 | LTRACE_EXIT; |
| 263 | } |
| 264 | |
| 265 | void i2c_init(void) |
| 266 | { |
| 267 | } |
| 268 | |
Travis Geiselbrecht | 39deded | 2009-01-24 20:12:27 -0800 | [diff] [blame] | 269 | #if WITH_LIB_CONSOLE |
Travis Geiselbrecht | bea5a4a | 2008-09-06 01:32:02 -0700 | [diff] [blame] | 270 | |
Travis Geiselbrecht | 39deded | 2009-01-24 20:12:27 -0800 | [diff] [blame] | 271 | #include <lib/console.h> |
Travis Geiselbrecht | bea5a4a | 2008-09-06 01:32:02 -0700 | [diff] [blame] | 272 | |
| 273 | static int cmd_i2c(int argc, const cmd_args *argv); |
| 274 | |
| 275 | STATIC_COMMAND_START |
| 276 | { "i2c", "i2c read/write commands", &cmd_i2c }, |
| 277 | STATIC_COMMAND_END(i2c); |
| 278 | |
| 279 | static int cmd_i2c(int argc, const cmd_args *argv) |
| 280 | { |
| 281 | int err; |
| 282 | |
| 283 | if (argc < 5) { |
| 284 | printf("not enough arguments\n"); |
| 285 | usage: |
| 286 | printf("%s read_reg <bus> <i2c address> <register>\n", argv[0].str); |
| 287 | printf("%s write_reg <bus> <i2c address> <register> <val>\n", argv[0].str); |
| 288 | return -1; |
| 289 | } |
| 290 | |
| 291 | int bus = argv[2].u; |
| 292 | uint8_t i2c_address = argv[3].u; |
| 293 | |
| 294 | if (!strcmp(argv[1].str, "read_reg")) { |
| 295 | uint8_t reg = argv[4].u; |
| 296 | uint8_t val; |
| 297 | |
| 298 | err = i2c_read_reg(bus, i2c_address, reg, &val); |
| 299 | printf("i2c_read_reg err %d, val 0x%hhx\n", err, val); |
| 300 | } else if (!strcmp(argv[1].str, "write_reg")) { |
| 301 | uint8_t reg = argv[4].u; |
| 302 | uint8_t val = argv[5].u; |
| 303 | err = i2c_write_reg(bus, i2c_address, reg, val); |
| 304 | printf("i2c_write_reg err %d\n", err); |
| 305 | } else { |
| 306 | printf("unrecognized subcommand\n"); |
| 307 | goto usage; |
| 308 | } |
| 309 | |
| 310 | return 0; |
| 311 | } |
| 312 | |
| 313 | #endif // WITH_APP_CONSOLE |
| 314 | |
| 315 | |