rt-thread-official/bsp/at91/at91sam9g45/drivers/at91_i2c_gpio.c

115 lines
2.2 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2012-04-25 weety first version
*/
#include <rtdevice.h>
#include <rthw.h>
#include <at91sam9g45.h>
static void at91_i2c_gpio_init(void)
{
AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_PIOA; //enable PIOA clock
AT91C_BASE_PIOA->PIO_PUER = (1 << 23);
AT91C_BASE_PIOA->PIO_PER = (1 << 23);
AT91C_BASE_PIOA->PIO_MDER = (1 << 23);
AT91C_BASE_PIOA->PIO_PUER = (1 << 24);
AT91C_BASE_PIOA->PIO_PER = (1 << 24);
AT91C_BASE_PIOA->PIO_MDER = (1 << 24);
AT91C_BASE_PIOA->PIO_OER = (1 << 23);
AT91C_BASE_PIOA->PIO_OER = (1 << 24);
AT91C_BASE_PIOA->PIO_SODR = (1 << 23);
AT91C_BASE_PIOA->PIO_SODR = (1 << 24);
}
static void at91_set_sda(void *data, rt_int32_t state)
{
if (state)
{
AT91C_BASE_PIOA->PIO_SODR = (1 << 23);
}
else
{
AT91C_BASE_PIOA->PIO_CODR = (1 << 23);
}
}
static void at91_set_scl(void *data, rt_int32_t state)
{
if (state)
{
AT91C_BASE_PIOA->PIO_SODR = (1 << 24);
}
else
{
AT91C_BASE_PIOA->PIO_CODR = (1 << 24);
}
}
static rt_int32_t at91_get_sda(void *data)
{
return AT91C_BASE_PIOA->PIO_PDSR & (1 << 23);
}
static rt_int32_t at91_get_scl(void *data)
{
return AT91C_BASE_PIOA->PIO_PDSR & (1 << 24);
}
static void at91_udelay (rt_uint32_t us)
{
rt_int32_t i;
for (; us > 0; us--)
{
i = 50000;
while(i > 0)
{
i--;
}
}
}
static const struct rt_i2c_bit_ops bit_ops = {
RT_NULL,
at91_set_sda,
at91_set_scl,
at91_get_sda,
at91_get_scl,
at91_udelay,
5,
100,
at91_i2c_gpio_init,
RT_FALSE
};
int at91_i2c_init(void)
{
struct rt_i2c_bus_device *bus;
bus = rt_malloc(sizeof(struct rt_i2c_bus_device));
if (bus == RT_NULL)
{
rt_kprintf("rt_malloc failed\n");
return -RT_ENOMEM;
}
rt_memset((void *)bus, 0, sizeof(struct rt_i2c_bus_device));
bus->priv = (void *)&bit_ops;
rt_i2c_bit_add_bus(bus, "i2c0");
return 0;
}
INIT_DEVICE_EXPORT(at91_i2c_init);