rt-thread-official/bsp/raspberry-pi/raspi3-32/driver/drv_rtc.c

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2020-01-10 10:38:21 +08:00
/*
* Copyright (c) 2006-2019, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2019-07-29 zdzn first version
*/
#include "drv_rtc.h"
#ifdef BSP_USING_RTC
#define RTC_I2C_BUS_NAME "i2c0"
#define RTC_ADDR 0x68
static struct rt_device rtc_device;
static struct rt_i2c_bus_device *i2c_bus = RT_NULL;
rt_uint8_t buf[]=
{
0x00, 0x00, 0x43, 0x15, 0x05, 0x01, 0x03, 0x19
};
rt_uint8_t i2c_write_read_rs(char* cmds, rt_uint32_t cmds_len, char* buf, rt_uint32_t buf_len)
{
rt_uint32_t remaining = cmds_len;
rt_uint32_t i = 0;
rt_uint8_t reason = BCM283X_I2C_REASON_OK;
/* Clear FIFO */
BCM283X_BSC_C(BCM283X_BSC0_BASE) |= (BSC_C_CLEAR_1 & BSC_C_CLEAR_1);
/* Clear Status */
BCM283X_BSC_S(BCM283X_BSC0_BASE) = BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE;
/* Set Data Length */
BCM283X_BSC_DLEN(BCM283X_BSC0_BASE) = cmds_len;
/* pre populate FIFO with max buffer */
while (remaining && (i < BSC_FIFO_SIZE))
{
BCM283X_BSC_FIFO(BCM283X_BSC0_BASE) = cmds[i];
i++;
remaining--;
}
/* Enable device and start transfer */
BCM283X_BSC_C(BCM283X_BSC0_BASE) |= BSC_C_I2CEN | BSC_C_ST;
/* poll for transfer has started (way to do repeated start, from BCM2835 datasheet) */
while (!(BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_TA))
{
/* Linux may cause us to miss entire transfer stage */
if (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_DONE)
break;
}
remaining = buf_len;
i = 0;
/* Send a repeated start with read bit set in address */
BCM283X_BSC_DLEN(BCM283X_BSC0_BASE) = buf_len;
BCM283X_BSC_C(BCM283X_BSC0_BASE) = BSC_C_I2CEN | BSC_C_ST | BSC_C_READ;
/* Wait for write to complete and first byte back. */
// DELAYMICROS(i2c_byte_wait_us * (cmds_len + 1));
/* wait for transfer to complete */
while (!(BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_DONE))
{
/* we must empty the FIFO as it is populated and not use any delay */
while (remaining && (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_RXD))
{
/* Read from FIFO, no barrier */
buf[i] = BCM283X_BSC_FIFO(BCM283X_BSC0_BASE);
i++;
remaining--;
}
}
/* transfer has finished - grab any remaining stuff in FIFO */
while (remaining && (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_RXD))
{
/* Read from FIFO */
buf[i] = BCM283X_BSC_FIFO(BCM283X_BSC0_BASE);
i++;
remaining--;
}
/* Received a NACK */
if (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_ERR)
{
reason = BCM283X_I2C_REASON_ERROR_NACK;
}
/* Received Clock Stretch Timeout */
else if (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_CLKT)
{
reason = BCM283X_I2C_REASON_ERROR_CLKT;
}
/* Not all data is sent */
else if (remaining)
{
reason = BCM283X_I2C_REASON_ERROR_DATA;
}
BCM283X_BSC_C(BCM283X_BSC0_BASE) = (BSC_S_DONE &BSC_S_DONE);
return reason;
}
rt_uint8_t i2c_write(rt_uint8_t* buf, rt_uint32_t len)
{
rt_uint32_t remaining = len;
rt_uint32_t i = 0;
rt_uint8_t reason = BCM283X_I2C_REASON_OK;
/* Clear FIFO */
BCM283X_BSC_C(BCM283X_BSC0_BASE) |= BSC_C_CLEAR_1 & BSC_C_CLEAR_1;
/* Clear Status */
BCM283X_BSC_S(BCM283X_BSC0_BASE) = BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE;
/* Set Data Length */
BCM283X_BSC_DLEN(BCM283X_BSC0_BASE) = len;
/* pre populate FIFO with max buffer */
while (remaining && (i < BSC_FIFO_SIZE))
{
BCM283X_BSC_FIFO(BCM283X_BSC0_BASE) = buf[i];
i++;
remaining--;
}
/* Enable device and start transfer */
BCM283X_BSC_C(BCM283X_BSC0_BASE) = BSC_C_I2CEN | BSC_C_ST;
/* Transfer is over when BCM2835_BSC_S_DONE */
while (!(BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_DONE))
{
while (remaining && (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_TXD))
{
/* Write to FIFO */
BCM283X_BSC_FIFO(BCM283X_BSC0_BASE) = buf[i];
i++;
remaining--;
}
}
/* Received a NACK */
if (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_ERR)
{
reason = BCM283X_I2C_REASON_ERROR_NACK;
}
/* Received Clock Stretch Timeout */
else if (BCM283X_BSC_S(BCM283X_BSC0_BASE) & BSC_S_CLKT)
{
reason = BCM283X_I2C_REASON_ERROR_CLKT;
}
/* Not all data is sent */
else if (remaining)
{
reason = BCM283X_I2C_REASON_ERROR_DATA;
}
BCM283X_BSC_C(BCM283X_BSC0_BASE) = BSC_S_DONE & BSC_S_DONE;
return reason;
}
static time_t raspi_get_timestamp(void)
{
struct tm tm_new = {0};
buf[0] = 0;
i2c_write_read_rs((char*)buf, 1, (char*)buf, 7);
tm_new.tm_year = ((buf[6] / 16) + 0x30) * 10 + (buf[6] % 16) + 0x30;
tm_new.tm_mon = ((buf[5] & 0x1F) / 16 + 0x30) + (buf[5] & 0x1F) % 16+ 0x30;
tm_new.tm_mday = ((buf[4] & 0x3F) / 16 + 0x30) + (buf[4] & 0x3F) % 16+ 0x30;
tm_new.tm_hour = ((buf[2] & 0x3F) / 16 + 0x30) + (buf[2] & 0x3F) % 16+ 0x30;
tm_new.tm_min = ((buf[1] & 0x7F) / 16 + 0x30) + (buf[1] & 0x7F) % 16+ 0x30;
tm_new.tm_sec = ((buf[0] & 0x7F) / 16 + 0x30) + (buf[0] & 0x7F) % 16+ 0x30;
return mktime(&tm_new);
}
static int raspi_set_timestamp(time_t timestamp)
{
struct tm *tblock;
tblock = localtime(&timestamp);
buf[0] = 0;
buf[1] = tblock->tm_sec;
buf[2] = tblock->tm_min;
buf[3] = tblock->tm_hour;
buf[4] = tblock->tm_wday;
buf[5] = tblock->tm_mday;
buf[6] = tblock->tm_mon;
buf[7] = tblock->tm_year;
i2c_write(buf, 8);
return RT_EOK;
}
static rt_err_t raspi_rtc_init(rt_device_t dev)
{
i2c_bus = (struct rt_i2c_bus_device *)rt_device_find(RTC_I2C_BUS_NAME);
raspi_set_timestamp(0);
return RT_EOK;
}
static rt_err_t raspi_rtc_open(rt_device_t dev, rt_uint16_t oflag)
{
GPIO_FSEL(BCM_GPIO_PIN_0, BCM283X_GPIO_FSEL_ALT0); /* SDA */
GPIO_FSEL(BCM_GPIO_PIN_1, BCM283X_GPIO_FSEL_ALT0); /* SCL */
return RT_EOK;
}
static rt_err_t raspi_rtc_close(rt_device_t dev)
{
GPIO_FSEL(BCM_GPIO_PIN_0, BCM283X_GPIO_FSEL_INPT); /* SDA */
GPIO_FSEL(BCM_GPIO_PIN_1, BCM283X_GPIO_FSEL_INPT); /* SCL */
return RT_EOK;
}
static rt_err_t raspi_rtc_control(rt_device_t dev, int cmd, void *args)
{
RT_ASSERT(dev != RT_NULL);
switch (cmd)
{
case RT_DEVICE_CTRL_RTC_GET_TIME:
*(rt_uint32_t *)args = raspi_get_timestamp();
break;
case RT_DEVICE_CTRL_RTC_SET_TIME:
raspi_set_timestamp(*(time_t *)args);
break;
default:
return RT_EINVAL;
}
return RT_EOK;
}
static rt_size_t raspi_rtc_read(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
{
raspi_rtc_control(dev, RT_DEVICE_CTRL_RTC_GET_TIME, buffer);
return size;
}
static rt_size_t raspi_rtc_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
{
raspi_rtc_control(dev, RT_DEVICE_CTRL_RTC_SET_TIME, (void *)buffer);
return size;
}
#ifdef RT_USING_DEVICE_OPS
const static struct rt_device_ops raspi_rtc_ops =
{
.init = raspi_rtc_init,
.open = raspi_rtc_open,
.close = raspi_rtc_close,
.read = raspi_rtc_read,
.write = raspi_rtc_write,
.control = raspi_rtc_control
};
#endif
int rt_hw_rtc_init(void)
{
rt_err_t ret = RT_EOK;
rtc_device.type = RT_Device_Class_RTC;
rtc_device.rx_indicate = RT_NULL;
rtc_device.tx_complete = RT_NULL;
#ifdef RT_USING_DEVICE_OPS
rtc_device.ops = &raspi_rtc_ops;
#else
rtc_device.init = raspi_rtc_init;
rtc_device.open = raspi_rtc_open;
rtc_device.close = raspi_rtc_close;
rtc_device.read = raspi_rtc_read;
rtc_device.write = raspi_rtc_write;
rtc_device.control = raspi_rtc_control;
#endif
rtc_device.user_data = RT_NULL;
/* register a rtc device */
ret = rt_device_register(&rtc_device, "rtc", RT_DEVICE_FLAG_RDWR);
return ret;
}
INIT_DEVICE_EXPORT(rt_hw_rtc_init);
#endif /* BSP_USING_RTC */