103 lines
1.9 KiB
C
103 lines
1.9 KiB
C
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#include "FreeRTOS.h"
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#include "board.h"
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#include "chip.h"
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#ifdef I2C_EEPROM_SLAVE_DEMO
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#if !defined(I2C0_SLAVE_MODE) && !defined(I2C1_SLAVE_MODE)
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#error "i2c eeprom slave demo needs a slave mode i2c dev"
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#endif
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#define I2C_EEPROM_24C02_ADDR 0x50
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#define I2C_EEPROM_24C02_SIZE 256
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struct eeprom_data {
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bool first_write;
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u8 buffer_idx;
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u8 buffer[];
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};
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static struct eeprom_data *g_eeprom = NULL;
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static struct i2c_adapter *g_adap = NULL;
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static int i2c_slave_eeprom_slave_cb(struct i2c_adapter *adap,
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enum i2c_slave_event event, u8 *val)
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{
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struct eeprom_data *eeprom = g_eeprom;
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switch (event) {
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case I2C_SLAVE_WRITE_RECEIVED:
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if (eeprom->first_write) {
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eeprom->buffer_idx = *val;
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eeprom->first_write = false;
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} else {
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eeprom->buffer[eeprom->buffer_idx++] = *val;
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}
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break;
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case I2C_SLAVE_READ_REQUESTED:
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*val = eeprom->buffer[eeprom->buffer_idx++];
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/*
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* Do not increment buffer_idx here, because we don't know if
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* this byte will be actually used. Read Linux I2C slave docs
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* for details.
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*/
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break;
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case I2C_SLAVE_STOP:
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case I2C_SLAVE_WRITE_REQUESTED:
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eeprom->first_write = true;
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break;
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default:
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break;
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}
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return 0;
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}
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int i2c_slave_eeprom_init(void)
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{
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struct eeprom_data *eeprom;
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int ret;
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unsigned size = I2C_EEPROM_24C02_SIZE;
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struct i2c_adapter *adap = NULL;
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eeprom = pvPortMalloc(sizeof(struct eeprom_data) + size);
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if (!eeprom)
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return -ENOMEM;
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g_eeprom = eeprom;
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eeprom->first_write = true;
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#ifdef I2C0_SLAVE_MODE
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adap = i2c_open("i2c0");
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#else
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adap = i2c_open("i2c1");
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#endif
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if (!adap) {
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printf("%s open i2c fail.\n", __func__);
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vPortFree(eeprom);
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return -1;
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}
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g_adap = adap;
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ret = i2c_slave_register(adap, I2C_EEPROM_24C02_ADDR, i2c_slave_eeprom_slave_cb);
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if (ret) {
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return ret;
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}
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return 0;
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};
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int i2c_slave_eeprom_uninit(void)
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{
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if (g_adap)
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i2c_slave_unregister(g_adap);
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if (g_eeprom)
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vPortFree(g_eeprom);
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return 0;
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}
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#endif
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