| /* |
| * Copyright (c) 2008 Travis Geiselbrecht |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files |
| * (the "Software"), to deal in the Software without restriction, |
| * including without limitation the rights to use, copy, modify, merge, |
| * publish, distribute, sublicense, and/or sell copies of the Software, |
| * and to permit persons to whom the Software is furnished to do so, |
| * subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| #include <debug.h> |
| #include <err.h> |
| #include <reg.h> |
| #include <string.h> |
| #include <platform.h> |
| #include <platform/omap3.h> |
| |
| #define LOCAL_TRACE 0 |
| |
| #define I2C_TIMEOUT 200 |
| |
| static const addr_t i2c_reg_base[] = { |
| I2C1_BASE, |
| I2C2_BASE, |
| I2C3_BASE, |
| }; |
| |
| #define I2C_REG_ADDR(bus, reg) (i2c_reg_base[bus] + (reg)) |
| #define I2C_REG(bus, reg) (*REG16(I2C_REG_ADDR(bus, reg))) |
| #define I2C_RMW_REG(bus, reg, startbit, width, val) RMWREG16(I2C_REG_ADDR(bus, reg), startbit, width, val) |
| |
| static void i2c_dump_bus(int bus) |
| { |
| hexdump((void *)i2c_reg_base[bus], 128); |
| } |
| |
| static void i2c_reset_bus(int bus) |
| { |
| I2C_REG(bus, I2C_CON) &= ~(1<<15); // make sure the bus is disabled |
| |
| /* reset the bus */ |
| I2C_REG(bus, I2C_SYSC) = (1<<1); |
| I2C_REG(bus, I2C_CON) = (1<<15); // enable the bus |
| while ((I2C_REG(bus, I2C_SYSS) & 1) == 0) |
| ; |
| |
| /* disable the bus again and set up some internals */ |
| I2C_REG(bus, I2C_CON) &= ~(1<<15); // make sure the bus is disabled |
| |
| /* set up the clock */ |
| I2C_REG(bus, I2C_PSC) = 23; // 96Mhz / 23 == 4Mhz |
| I2C_REG(bus, I2C_SCLL) = 13; |
| I2C_REG(bus, I2C_SCLH) = 15; // 4Mhz / combined divider of 40 (13+7 + 15+5) == 100khz |
| |
| /* slave address */ |
| I2C_REG(bus, I2C_OA0) = 1; // XXX made this up |
| |
| /* fifo is set to 1 byte trigger */ |
| I2C_REG(bus, I2C_BUF) = 0; |
| |
| /* disable all interrupts */ |
| I2C_REG(bus, I2C_IE) = 0; |
| |
| /* enable the bus */ |
| I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<9); // enable, master, transmitter mode |
| } |
| |
| static void i2c_wait_for_bb(int bus) |
| { |
| I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| while (I2C_REG(bus, I2C_STAT) & (1<<12)) { |
| I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| } |
| I2C_REG(bus, I2C_STAT) = 0xffff; // clear whatever is pending |
| } |
| |
| int i2c_transmit(int bus, uint8_t address, const void *buf, size_t count) |
| { |
| int err; |
| |
| LTRACEF("bus %d, address 0x%hhx, buf %p, count %zd\n", bus, address, buf, count); |
| |
| i2c_wait_for_bb(bus); |
| |
| I2C_REG(bus, I2C_SA) = address; |
| I2C_REG(bus, I2C_CNT) = count; |
| I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<9)|(1<<1)|(1<<0); // enable, master, transmit, STP, STT |
| |
| time_t t = current_time(); |
| |
| const uint8_t *ptr = (const uint8_t *)buf; |
| for(;;) { |
| uint16_t stat = I2C_REG(bus, I2C_STAT); |
| if (stat & (1<<1)) { |
| // NACK |
| // printf("NACK\n"); |
| err = -1; |
| goto out; |
| } |
| if (stat & (1<<0)) { |
| // AL (arbitration lost) |
| // printf("arbitration lost!\n"); |
| err = -1; |
| goto out; |
| } |
| if (stat & (1<<2)) { |
| // ARDY |
| // printf("ARDY, completed\n"); |
| break; |
| } |
| if (stat & (1<<4)) { |
| // RRDY |
| // printf("XRDY\n"); |
| |
| // transmit a byte |
| *REG8(I2C_REG_ADDR(bus, I2C_DATA)) = *ptr; |
| ptr++; |
| } |
| I2C_REG(bus, I2C_STAT) = stat; |
| |
| if (current_time() - t > I2C_TIMEOUT) { |
| // printf("i2c timeout\n"); |
| err = ERR_TIMED_OUT; |
| goto out; |
| } |
| } |
| |
| err = 0; |
| |
| out: |
| I2C_REG(bus, I2C_STAT) = 0xffff; |
| I2C_REG(bus, I2C_CNT) = 0; |
| |
| return err; |
| } |
| |
| int i2c_receive(int bus, uint8_t address, void *buf, size_t count) |
| { |
| int err; |
| |
| LTRACEF("bus %d, address 0x%hhx, buf %p, count %zd\n", bus, address, buf, count); |
| |
| i2c_wait_for_bb(bus); |
| |
| I2C_REG(bus, I2C_SA) = address; |
| I2C_REG(bus, I2C_CNT) = count; |
| I2C_REG(bus, I2C_CON) = (1<<15)|(1<<10)|(1<<1)|(1<<0); // enable, master, STP, STT |
| |
| time_t t = current_time(); |
| |
| uint8_t *ptr = (uint8_t *)buf; |
| for(;;) { |
| uint16_t stat = I2C_REG(bus, I2C_STAT); |
| if (stat & (1<<1)) { |
| // NACK |
| // printf("NACK\n"); |
| err = -1; |
| goto out; |
| } |
| if (stat & (1<<0)) { |
| // AL (arbitration lost) |
| // printf("arbitration lost!\n"); |
| err = -1; |
| goto out; |
| } |
| if (stat & (1<<2)) { |
| // ARDY |
| // printf("ARDY, completed\n"); |
| break; |
| } |
| if (stat & (1<<3)) { |
| // RRDY |
| // printf("RRDY\n"); |
| |
| // read a byte, since our fifo threshold is set to 1 byte |
| *ptr = *REG8(I2C_REG_ADDR(bus, I2C_DATA)); |
| ptr++; |
| } |
| I2C_REG(bus, I2C_STAT) = stat; |
| |
| if (current_time() - t > I2C_TIMEOUT) { |
| // printf("i2c timeout\n"); |
| err = ERR_TIMED_OUT; |
| goto out; |
| } |
| } |
| |
| err = 0; |
| |
| out: |
| I2C_REG(bus, I2C_STAT) = 0xffff; |
| I2C_REG(bus, I2C_CNT) = 0; |
| |
| return err; |
| } |
| |
| int i2c_write_reg(int bus, uint8_t address, uint8_t reg, uint8_t val) |
| { |
| uint8_t buf[2]; |
| |
| buf[0] = reg; |
| buf[1] = val; |
| |
| return i2c_transmit(bus, address, buf, 2); |
| } |
| |
| int i2c_read_reg(int bus, uint8_t address, uint8_t reg, uint8_t *val) |
| { |
| int err = i2c_transmit(bus, address, ®, 1); |
| if (err < 0) |
| return err; |
| |
| return i2c_receive(bus, address, val, 1); |
| } |
| |
| |
| void i2c_init_early(void) |
| { |
| LTRACE_ENTRY; |
| |
| /* enable clocks on i2c 0-2 */ |
| RMWREG32(CM_FCLKEN1_CORE, 15, 3, 0x7), |
| RMWREG32(CM_ICLKEN1_CORE, 15, 3, 0x7), |
| |
| i2c_reset_bus(0); |
| i2c_reset_bus(1); |
| i2c_reset_bus(2); |
| |
| #if 0 |
| // write something into a reg |
| char buf[2]; |
| i2c_write_reg(0, 0x4b, 0x14, 0x99); |
| i2c_write_reg(0, 0x4b, 0x15, 0x98); |
| |
| i2c_read_reg(0, 0x4b, 0x15, buf); |
| printf("0x%hhx\n", buf[0]); |
| i2c_read_reg(0, 0x4b, 0x14, buf); |
| printf("0x%hhx\n", buf[0]); |
| |
| int i; |
| for (i=0; i < 255; i++) { |
| char buf[1]; |
| buf[0] = i; |
| i2c_transmit(0, 0x4b, buf, 1); |
| i2c_receive(0, 0x4b, buf, sizeof(buf)); |
| printf("0x%hhx\n", buf[0]); |
| } |
| #endif |
| |
| LTRACE_EXIT; |
| } |
| |
| void i2c_init(void) |
| { |
| } |
| |
| #if WITH_LIB_CONSOLE |
| |
| #include <lib/console.h> |
| |
| static int cmd_i2c(int argc, const cmd_args *argv); |
| |
| STATIC_COMMAND_START |
| { "i2c", "i2c read/write commands", &cmd_i2c }, |
| STATIC_COMMAND_END(i2c); |
| |
| static int cmd_i2c(int argc, const cmd_args *argv) |
| { |
| int err; |
| |
| if (argc < 5) { |
| printf("not enough arguments\n"); |
| usage: |
| printf("%s read_reg <bus> <i2c address> <register>\n", argv[0].str); |
| printf("%s write_reg <bus> <i2c address> <register> <val>\n", argv[0].str); |
| return -1; |
| } |
| |
| int bus = argv[2].u; |
| uint8_t i2c_address = argv[3].u; |
| |
| if (!strcmp(argv[1].str, "read_reg")) { |
| uint8_t reg = argv[4].u; |
| uint8_t val; |
| |
| err = i2c_read_reg(bus, i2c_address, reg, &val); |
| printf("i2c_read_reg err %d, val 0x%hhx\n", err, val); |
| } else if (!strcmp(argv[1].str, "write_reg")) { |
| uint8_t reg = argv[4].u; |
| uint8_t val = argv[5].u; |
| err = i2c_write_reg(bus, i2c_address, reg, val); |
| printf("i2c_write_reg err %d\n", err); |
| } else { |
| printf("unrecognized subcommand\n"); |
| goto usage; |
| } |
| |
| return 0; |
| } |
| |
| #endif // WITH_APP_CONSOLE |
| |
| |