diff options
| -rw-r--r-- | fw/fe310/eos/i2c.c | 116 | ||||
| -rw-r--r-- | fw/fe310/eos/i2c.h | 9 |
2 files changed, 125 insertions, 0 deletions
diff --git a/fw/fe310/eos/i2c.c b/fw/fe310/eos/i2c.c new file mode 100644 index 0000000..72e53ae --- /dev/null +++ b/fw/fe310/eos/i2c.c @@ -0,0 +1,116 @@ +#include <stdlib.h> +#include <stdint.h> + +#include "encoding.h" +#include "platform.h" +#include "prci_driver.h" + +#include "eos.h" +#include "i2c.h" + +void eos_i2c_start(uint32_t baud_rate) { + eos_i2c_set_baud_rate(baud_rate); + + GPIO_REG(GPIO_PULLUP_EN) &= ~(1 << IOF_I2C0_SCL); + GPIO_REG(GPIO_OUTPUT_XOR) &= ~(1 << IOF_I2C0_SCL); + + GPIO_REG(GPIO_PULLUP_EN) &= ~(1 << IOF_I2C0_SDA); + GPIO_REG(GPIO_OUTPUT_XOR) &= ~(1 << IOF_I2C0_SDA); + + GPIO_REG(GPIO_IOF_SEL) &= ~IOF0_I2C0_MASK; + GPIO_REG(GPIO_IOF_EN) |= IOF0_I2C0_MASK; +} + +void eos_i2c_stop(void) { + GPIO_REG(GPIO_PULLUP_EN) |= (1 << IOF_I2C0_SCL); + GPIO_REG(GPIO_PULLUP_EN) |= (1 << IOF_I2C0_SDA); + GPIO_REG(GPIO_IOF_EN) &= ~IOF0_I2C0_MASK; +} + +void eos_i2c_set_baud_rate(uint32_t baud_rate) { + unsigned long clock_rate = PRCI_get_cpu_freq(); + uint16_t prescaler = (clock_rate / (baud_rate * 5)) - 1; + + I2C0_REGB(I2C_CONTROL) &= ~I2C_CONTROL_EN; + I2C0_REGB(I2C_PRESCALE_LOW) = prescaler & 0xFF; + I2C0_REGB(I2C_PRESCALE_HIGH) = (prescaler >> 8) & 0xFF; + I2C0_REGB(I2C_CONTROL) |= I2C_CONTROL_EN; +} + + +static int i2c_addr(uint8_t addr, uint8_t rw_flag) { + I2C0_REGB(I2C_TRANSMIT) = ((addr & 0x7F) << 1) | (rw_flag & 0x1); + I2C0_REGB(I2C_COMMAND) = I2C_CMD_START | I2C_CMD_WRITE; + while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP); + + if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR; + return EOS_OK; +} + +static int i2c_reg(uint8_t reg) { + I2C0_REGB(I2C_TRANSMIT) = reg; + I2C0_REGB(I2C_COMMAND) = I2C_CMD_WRITE; + while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP); + + if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR; + return EOS_OK; +} + +int eos_i2c_read(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len) { + uint8_t cmd; + int rv; + int i; + + rv = i2c_addr(addr, I2C_WRITE); + if (rv) return rv; + + rv = i2c_reg(reg); + if (rv) return rv; + + rv = i2c_addr(addr, I2C_READ); + if (rv) return rv; + + cmd = I2C_CMD_READ; + + for (i=0; i<len; i++) { + /* Set NACK to end read, and generate STOP condition */ + if (i == (len - 1)) cmd |= I2C_CMD_ACK | I2C_CMD_STOP; + I2C0_REGB(I2C_COMMAND) = cmd; + while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP); + buffer[i] = I2C0_REGB(I2C_RECEIVE); + } + + return EOS_OK; +} + +int eos_i2c_write(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len) { + uint8_t cmd; + int rv; + int i; + + rv = i2c_addr(addr, I2C_WRITE); + if (rv) return rv; + + rv = i2c_reg(reg); + if (rv) return rv; + + cmd = I2C_CMD_WRITE; + + for (i=0; i<len; i++) { + if (i == (len - 1)) cmd |= I2C_CMD_STOP; + I2C0_REGB(I2C_TRANSMIT) = buffer[i]; + I2C0_REGB(I2C_COMMAND) = cmd; + while (I2C0_REGB(I2C_STATUS) & I2C_STATUS_TIP); + if (I2C0_REGB(I2C_STATUS) & I2C_STATUS_RXACK) return EOS_ERR; + } + + return EOS_OK; +} + +int eos_i2c_read8(uint8_t addr, uint8_t reg, uint8_t *data) { + return eos_i2c_read(addr, reg, data, 1); +} + +int eos_i2c_write8(uint8_t addr, uint8_t reg, uint8_t data) { + return eos_i2c_write(addr, reg, &data, 1); +} diff --git a/fw/fe310/eos/i2c.h b/fw/fe310/eos/i2c.h new file mode 100644 index 0000000..9692ea0 --- /dev/null +++ b/fw/fe310/eos/i2c.h @@ -0,0 +1,9 @@ +#include <stdint.h> + +void eos_i2c_start(uint32_t baud_rate); +void eos_i2c_stop(void); +void eos_i2c_set_baud_rate(uint32_t baud_rate); +int eos_i2c_read(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len); +int eos_i2c_write(uint8_t addr, uint8_t reg, uint8_t *buffer, uint16_t len); +int eos_i2c_read8(uint8_t addr, uint8_t reg, uint8_t *data); +int eos_i2c_write8(uint8_t addr, uint8_t reg, uint8_t data); |