From a1b7a1fb1f5a5ad5b6f34b576dd0a1a2cce2f210 Mon Sep 17 00:00:00 2001
From: Uros Majstorovic <majstor@majstor.org>
Date: Wed, 24 Feb 2021 03:17:51 +0100
Subject: i2c driver initial import
---
fw/fe310/eos/i2c.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fw/fe310/eos/i2c.h | 9 +++++
2 files changed, 125 insertions(+)
create mode 100644 fw/fe310/eos/i2c.c
create mode 100644 fw/fe310/eos/i2c.h
(limited to 'fw/fe310/eos')
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);
--
cgit v1.2.3