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rt-thread-official/bsp/raspberry-pi/raspi4-32/driver/drv_i2c.c

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/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2020-11-28 bigmagic first version
*/
#include "drv_i2c.h"
#include "drv_gpio.h"
#include "raspi4.h"
#include "mbox.h"
/*
* (3.3v) -1 2-
* (SDA1/SDA3) -3 4-
* (SCL1/SCL3) -5 6-
* (SDA3) -7 8-
* -9 10-
* -11 12-
* -13 14-
* -15 16-
* -17 18-
* -19 20-
* (SCL4) -21 22-
* -23 24- (SDA4)
* -25 26- (SCL4)
* -27 28-
* (SCL3) -29 30-
* (SDA4) -31 32-
*/
#define DBG_TAG "drv.i2c"
#define DBG_LVL DBG_INFO
#include <rtdbg.h>
struct raspi_i2c_hw_config
{
rt_uint32_t bsc_num;
rt_uint32_t bsc_rate;
rt_uint32_t bsc_address;
rt_uint32_t sda_pin;
rt_uint32_t scl_pin;
rt_uint32_t sda_mode;
rt_uint32_t scl_mode;
};
rt_uint8_t i2c_read_or_write(volatile rt_uint32_t base, rt_uint8_t* buf, rt_uint32_t len, rt_uint8_t flag)
{
rt_uint32_t status;
rt_uint32_t remaining = len;
rt_uint32_t i = 0;
rt_uint8_t reason = I2C_REASON_OK;
/* Clear FIFO */
BSC_C(base) |= (BSC_C_CLEAR_1 & BSC_C_CLEAR_1);
/* Clear Status */
BSC_S(base) = BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE;
/* Set Data Length */
BSC_DLEN(base) = len;
if (flag)
{
/* Start read */
BSC_C(base) = BSC_C_I2CEN | BSC_C_ST | BSC_C_READ;
/* wait for transfer to complete */
while (!(BSC_S(base) & BSC_S_DONE))
{
/* we must empty the FIFO as it is populated and not use any delay */
while (remaining && (BSC_S(base) & BSC_S_RXD))
{
/* Read from FIFO, no barrier */
buf[i] = BSC_FIFO(base);
i++;
remaining--;
}
}
/* transfer has finished - grab any remaining stuff in FIFO */
while (remaining && (BSC_S(base) & BSC_S_RXD))
{
/* Read from FIFO, no barrier */
buf[i] = BSC_FIFO(base);
i++;
remaining--;
}
}
else
{
LOG_D("i2c%d write start", flag);
/* pre populate FIFO with max buffer */
while (remaining && (i < BSC_FIFO_SIZE))
{
BSC_FIFO(base) = buf[i];
i++;
remaining--;
}
/* Enable device and start transfer */
BSC_C(base) = BSC_C_I2CEN | BSC_C_ST;
/* Transfer is over when BCM2835_BSC_S_DONE */
while (!(BSC_S(base) & BSC_S_DONE))
{
while (remaining && (BSC_S(base) & BSC_S_TXD))
{
/* Write to FIFO */
BSC_FIFO(base) = buf[i];
i++;
remaining--;
}
}
LOG_D("i2c%d write end", flag);
}
status = BSC_S(base);
if (status & BSC_S_ERR)
{
reason = I2C_REASON_ERROR_NACK;
}
else if (status & BSC_S_CLKT)
{
reason = I2C_REASON_ERROR_CLKT;
}
else if (remaining)
{
reason = I2C_REASON_ERROR_DATA;
}
BSC_C(base) |= (BSC_S_DONE & BSC_S_DONE);
return reason;
}
static rt_ssize_t raspi_i2c_mst_xfer(struct rt_i2c_bus_device *bus,
struct rt_i2c_msg msgs[],
rt_uint32_t num)
{
rt_size_t i;
rt_uint8_t reason;
RT_ASSERT(bus != RT_NULL);
struct raspi_i2c_hw_config *i2c_hw_config = (struct raspi_i2c_hw_config*)(bus->priv);
//Slave Address
BSC_A(i2c_hw_config->bsc_address) = msgs->addr;
for (i = 0; i < num; i++)
{
if (msgs[i].flags & RT_I2C_RD)
reason = i2c_read_or_write(i2c_hw_config->bsc_address, msgs->buf, msgs->len, 1);
else
reason = i2c_read_or_write(i2c_hw_config->bsc_address, msgs->buf, msgs->len, 0);
}
return (reason == 0)? i : 0;
}
static rt_ssize_t raspi_i2c_slv_xfer(struct rt_i2c_bus_device *bus,
struct rt_i2c_msg msgs[],
rt_uint32_t num)
{
return 0;
}
static rt_err_t raspi_i2c_bus_control(struct rt_i2c_bus_device *bus,
int cmd,
void *args)
{
return RT_EOK;
}
static rt_err_t raspi_i2c_configure(struct raspi_i2c_hw_config *cfg)
{
RT_ASSERT(cfg != RT_NULL);
rt_uint32_t apb_clock = 0;
prev_raspi_pin_mode(cfg->sda_pin, cfg->sda_mode);//sda
prev_raspi_pin_mode(cfg->scl_pin, cfg->scl_mode);//scl
/* use 0xFFFE mask to limit a max value and round down any odd number */
apb_clock = bcm271x_mbox_clock_get_rate(CORE_CLK_ID);
rt_uint32_t divider = (apb_clock / cfg->bsc_rate) & 0xFFFE;
BSC_DIV(cfg->bsc_address) = (rt_uint16_t)divider;
return RT_EOK;
}
static const struct rt_i2c_bus_device_ops raspi_i2c_ops =
{
.master_xfer = raspi_i2c_mst_xfer,
.slave_xfer = raspi_i2c_slv_xfer,
.i2c_bus_control = raspi_i2c_bus_control,
};
#if defined (BSP_USING_I2C0)
#define I2C0_BUS_NAME "i2c0"
static struct raspi_i2c_hw_config hw_device0 =
{
.bsc_num = 0,
.bsc_rate = 100000,//100k
.bsc_address = BSC0_BASE,
.sda_pin = GPIO_PIN_0,
.scl_pin = GPIO_PIN_1,
.sda_mode = ALT0,
.scl_mode = ALT0,
};
struct rt_i2c_bus_device device0 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device0,
};
#endif
#if defined (BSP_USING_I2C1)
#define I2C1_BUS_NAME "i2c1"
static struct raspi_i2c_hw_config hw_device1 =
{
.bsc_num = 1,
.bsc_rate = 100000,//100k
.bsc_address = BSC1_BASE,
.sda_pin = GPIO_PIN_2,
.scl_pin = GPIO_PIN_3,
.sda_mode = ALT0,
.scl_mode = ALT0,
};
struct rt_i2c_bus_device device1 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device1,
};
#endif
#if defined (BSP_USING_I2C3)
#define I2C3_BUS_NAME "i2c3"
static struct raspi_i2c_hw_config hw_device3 =
{
.bsc_num = 3,
.bsc_rate = 100000,//100k
.bsc_address = BSC3_BASE,
#ifndef BSP_USING_I2C3_0
.sda_pin = GPIO_PIN_2,
.scl_pin = GPIO_PIN_3,
#else
.sda_pin = GPIO_PIN_4,
.scl_pin = GPIO_PIN_5,
#endif
.sda_mode = ALT5,
.scl_mode = ALT5,
};
struct rt_i2c_bus_device device3 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device3,
};
#endif
#if defined (BSP_USING_I2C4)
#define I2C4_BUS_NAME "i2c4"
static struct raspi_i2c_hw_config hw_device4 =
{
.bsc_num = 4,
.bsc_rate = 100000,//100k
.bsc_address = BSC4_BASE,
#ifdef BSP_USING_I2C4_0
.sda_pin = GPIO_PIN_6,
.scl_pin = GPIO_PIN_7,
#else
.sda_pin = GPIO_PIN_8,
.scl_pin = GPIO_PIN_9,
#endif
.sda_mode = ALT5,
.scl_mode = ALT5,
};
struct rt_i2c_bus_device device4 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device4,
};
#endif
#if defined (BSP_USING_I2C5)
#define I2C5_BUS_NAME "i2c5"
static struct raspi_i2c_hw_config hw_device5 =
{
.bsc_num = 5,
.bsc_rate = 100000,//100k
.bsc_address = BSC5_BASE,
#ifdef BSP_USING_I2C5_0
.sda_pin = GPIO_PIN_10,
.scl_pin = GPIO_PIN_11,
#else
.sda_pin = GPIO_PIN_12,
.scl_pin = GPIO_PIN_13,
#endif
.sda_mode = ALT5,
.scl_mode = ALT5,
};
struct rt_i2c_bus_device device5 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device5,
};
#endif
#if defined (BSP_USING_I2C6)
#define I2C6_BUS_NAME "i2c6"
static struct raspi_i2c_hw_config hw_device6 =
{
.bsc_num = 6,
.bsc_rate = 100000,//100k
.bsc_address = BSC6_BASE,
#ifdef BSP_USING_I2C5_0
.sda_pin = GPIO_PIN_0,
.scl_pin = GPIO_PIN_1,
#else
.sda_pin = GPIO_PIN_22,
.scl_pin = GPIO_PIN_23,
#endif
.sda_mode = ALT5,
.scl_mode = ALT5,
};
struct rt_i2c_bus_device device6 =
{
.ops = &raspi_i2c_ops,
.priv = (void *)&hw_device6,
};
#endif
int rt_hw_i2c_init(void)
{
#if defined(BSP_USING_I2C0)
raspi_i2c_configure(&hw_device0);
rt_i2c_bus_device_register(&device0, I2C0_BUS_NAME);
#endif
#if defined(BSP_USING_I2C1)
raspi_i2c_configure(&hw_device1);
rt_i2c_bus_device_register(&device1, I2C1_BUS_NAME);
#endif
#if defined(BSP_USING_I2C3)
raspi_i2c_configure(&hw_device3);
rt_i2c_bus_device_register(&device3, I2C3_BUS_NAME);
#endif
#if defined(BSP_USING_I2C4)
raspi_i2c_configure(&hw_device4);
rt_i2c_bus_device_register(&device4, I2C4_BUS_NAME);
#endif
#if defined(BSP_USING_I2C5)
raspi_i2c_configure(&hw_device5);
rt_i2c_bus_device_register(&device5, I2C5_BUS_NAME);
#endif
#if defined(BSP_USING_I2C6)
raspi_i2c_configure(&hw_device6);
rt_i2c_bus_device_register(&device6, I2C6_BUS_NAME);
#endif
return 0;
}
INIT_DEVICE_EXPORT(rt_hw_i2c_init);
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