tnt has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-e1-hardware/+/30065 )
Change subject: icE1usb fw: Import I2C peripheral driver ......................................................................
icE1usb fw: Import I2C peripheral driver
Signed-off-by: Sylvain Munaut tnt@246tNt.com Change-Id: Ib729bb5f4e94eec25c86517042cdfdcb6847ba25 --- M firmware/ice40-riscv/icE1usb/Makefile A firmware/ice40-riscv/icE1usb/i2c.c A firmware/ice40-riscv/icE1usb/i2c.h 3 files changed, 149 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-e1-hardware refs/changes/65/30065/1
diff --git a/firmware/ice40-riscv/icE1usb/Makefile b/firmware/ice40-riscv/icE1usb/Makefile index 3fde2ca..f385408 100644 --- a/firmware/ice40-riscv/icE1usb/Makefile +++ b/firmware/ice40-riscv/icE1usb/Makefile @@ -55,6 +55,7 @@ gps.h \ gpsdo.h \ ice1usb_proto.h \ + i2c.h \ misc.h \ usb_desc_ids.h \ usb_dev.h \ @@ -69,6 +70,7 @@ fw_app.c \ gps.c \ gpsdo.c \ + i2c.c \ misc.c \ usb_desc_app.c \ usb_dev.c \ diff --git a/firmware/ice40-riscv/icE1usb/i2c.c b/firmware/ice40-riscv/icE1usb/i2c.c new file mode 100644 index 0000000..08a7dfa --- /dev/null +++ b/firmware/ice40-riscv/icE1usb/i2c.c @@ -0,0 +1,125 @@ +/* + * i2c.c + * + * Copyright (C) 2021-2022 Sylvain Munaut tnt@246tNt.com + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#include <stdint.h> +#include <stdbool.h> + +#include "console.h" + +#include "config.h" + + +struct i2c { + uint32_t csr; +} __attribute__((packed,aligned(4))); + +#define I2C_CMD_START (0 << 12) +#define I2C_CMD_STOP (1 << 12) +#define I2C_CMD_WRITE (2 << 12) +#define I2C_CMD_READ (3 << 12) + +#define I2C_GET_RESP (1 << 15) +#define I2C_ACK (0 << 8) /* ack bit value = 0 means ACK */ +#define I2C_NAK (1 << 8) /* ack bit value = 1 means NAK */ + +#define I2C_VALID (1 << 31) + + +static volatile struct i2c * const i2c_regs = (void*)(I2C_BASE); + + +static inline uint32_t +_i2c_wait(void) +{ + uint32_t v; + + do { + v = i2c_regs->csr; + } while (!(v & I2C_VALID)); + + return v & 0x1ff; +} + +bool +i2c_ready(void) +{ + return i2c_regs->csr & (1 << 31); +} + +void +i2c_start(void) +{ + i2c_regs->csr = I2C_CMD_START; +} + +void +i2c_stop(void) +{ + i2c_regs->csr = I2C_CMD_STOP; +} + +bool +i2c_write(uint8_t data) +{ + i2c_regs->csr = I2C_CMD_WRITE | data; + return (_i2c_wait() & (I2C_ACK | I2C_NAK)) == I2C_ACK; +} + +uint8_t +i2c_read(bool ack) +{ + i2c_regs->csr = I2C_CMD_READ | I2C_GET_RESP | (ack ? I2C_ACK : I2C_NAK); + return _i2c_wait() & 0xff; +} + + +bool +i2c_write_reg(uint8_t dev, uint8_t reg, uint8_t val) +{ + bool rv = true; + i2c_start(); + rv = rv && i2c_write(dev); + rv = rv && i2c_write(reg); + rv = rv && i2c_write(val); + i2c_stop(); + return rv; +} + +bool +i2c_read_reg(uint8_t dev, uint8_t reg, uint8_t *val) +{ + bool rv = true; + i2c_start(); + rv = rv && i2c_write(dev); + rv = rv && i2c_write(reg); + if (rv) + i2c_start(); + rv = rv && i2c_write(dev|1); + *val = rv ? i2c_read(false) : 0x00; // NAK + i2c_stop(); + return rv; +} + + +bool +i2c_probe(uint8_t dev) +{ + bool rv; + i2c_start(); + rv = i2c_write(dev); + i2c_stop(); + return rv; +} + +void +i2c_scan(void) +{ + for (uint8_t addr=0; addr<128; addr++) { + if (i2c_probe(addr << 1)) + printf("I2C @ %08x\n", addr << 1); + } +} diff --git a/firmware/ice40-riscv/icE1usb/i2c.h b/firmware/ice40-riscv/icE1usb/i2c.h new file mode 100644 index 0000000..da11eb5 --- /dev/null +++ b/firmware/ice40-riscv/icE1usb/i2c.h @@ -0,0 +1,22 @@ +/* + * i2c.h + * + * Copyright (C) 2021-2022 Sylvain Munaut tnt@246tNt.com + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#pragma once + +#include <stdbool.h> +#include <stdint.h> + +void i2c_start(void); +void i2c_stop(void); +bool i2c_write(uint8_t data); +uint8_t i2c_read(bool ack); + +bool i2c_write_reg(uint8_t dev, uint8_t reg, uint8_t val); +bool i2c_read_reg (uint8_t dev, uint8_t reg, uint8_t *val); + +bool i2c_probe(uint8_t dev); +void i2c_scan(void);
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tnt