rt-thread-official/components/drivers/spi/spi_core.c

#include <drivers/spi.h>

extern rt_err_t rt_spi_bus_device_init(struct rt_spi_bus* bus, const char* name);
extern rt_err_t rt_spidev_device_init(struct rt_spi_device* dev, const char* name);

rt_err_t rt_spi_bus_register(struct rt_spi_bus* bus, const char* name, const struct rt_spi_ops* ops)
{
	rt_err_t result;

	result = rt_spi_bus_device_init(bus, name);
	if (result != RT_EOK) return result;

	/* initialize mutex lock */
	rt_mutex_init(&(bus->lock), name, RT_IPC_FLAG_FIFO);
	/* set ops */
	bus->ops = ops;
	/* initialize owner */
	bus->owner = RT_NULL;

	return RT_EOK;
}

rt_err_t rt_spi_bus_attach_device(struct rt_spi_device* device, const char* name, const char* bus_name, void* user_data)
{
	rt_device_t bus;

	/* get physical spi bus */
	bus = rt_device_find(bus_name);
	if (bus != RT_NULL && bus->type == RT_Device_Class_SPIBUS)
	{
		device->bus = (struct rt_spi_bus*)bus;

		/* initialize spidev device */
		rt_spidev_device_init(device, name);
		rt_memset(&device->config, 0, sizeof(device->config));
		device->parent.user_data = user_data;
	}

	/* not found the host bus */
	return -RT_ERROR;
}

rt_err_t rt_spi_configure(struct rt_spi_device* device, struct rt_spi_configuration* cfg)
{
	rt_err_t result;

	RT_ASSERT(device != RT_NULL);

	/* set configuration */
	device->config.data_width = cfg->data_width;
	device->config.mode = cfg->mode & RT_SPI_MODE_MASK ;
	device->config.max_hz = cfg->max_hz ;

	if (device->bus != RT_NULL)
	{
		result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
		if (result == RT_EOK)
		{
			if (device->bus->owner == device)
			{
				device->bus->ops->configure(device, &device->config);
			}

			/* release lock */
			rt_mutex_release(&(device->bus->lock));
		}
	}

	return RT_EOK;
}

rt_err_t rt_spi_send_then_send(struct rt_spi_device* device, const void *send_buf1, rt_size_t send_length1,
		const void* send_buf2, rt_size_t send_length2)
{
	rt_err_t result;
	struct rt_spi_message message;

	RT_ASSERT(device != RT_NULL);
	RT_ASSERT(device->bus != RT_NULL);

	result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
	if (result == RT_EOK)
	{
		if (device->bus->owner != device)
		{
			/* not the same owner as current, re-configure SPI bus */
			result = device->bus->ops->configure(device, &device->config);
			if (result == RT_EOK)
			{
				/* set SPI bus owner */
				device->bus->owner = device;
			}
			else
			{
				/* configure SPI bus failed */
				result = -RT_EIO;
				goto __exit;
			}
		}

		/* send data1 */
		message.send_buf = send_buf1;
		message.recv_buf = RT_NULL;
		message.length = send_length1;
		message.cs_take = 1;
		message.cs_release = 0;

		result = device->bus->ops->xfer(device, &message);
		if (result == 0)
		{
			result = -RT_EIO;
			goto __exit;
		}

		/* send data2 */
		message.send_buf = send_buf2;
		message.recv_buf = RT_NULL;
		message.length = send_length2;
		message.cs_take = 0;
		message.cs_release = 1;

		result = device->bus->ops->xfer(device, &message);
		if (result == 0)
		{
			result = -RT_EIO;
			goto __exit;
		}

		result = RT_EOK;
	}
	else
	{
		return -RT_EIO;
	}

__exit:
	rt_mutex_release(&(device->bus->lock));
	return result;
}

rt_err_t rt_spi_send_then_recv(struct rt_spi_device* device, const void *send_buf, rt_size_t send_length,
		void* recv_buf, rt_size_t recv_length)
{
	rt_err_t result;
	struct rt_spi_message message;

	RT_ASSERT(device != RT_NULL);
	RT_ASSERT(device->bus != RT_NULL);

	result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
	if (result == RT_EOK)
	{
		if (device->bus->owner != device)
		{
			/* not the same owner as current, re-configure SPI bus */
			result = device->bus->ops->configure(device, &device->config);
			if (result == RT_EOK)
			{
				/* set SPI bus owner */
				device->bus->owner = device;
			}
			else
			{
				/* configure SPI bus failed */
				result = -RT_EIO;
				goto __exit;
			}
		}

		/* send data */
		message.send_buf = send_buf;
		message.recv_buf = RT_NULL;
		message.length = send_length;
		message.cs_take = 1;
		message.cs_release = 0;

		result = device->bus->ops->xfer(device, &message);
		if (result == 0)
		{
			result = -RT_EIO;
			goto __exit;
		}

		/* recv data */
		message.send_buf = RT_NULL;
		message.recv_buf = recv_buf;
		message.length = recv_length;
		message.cs_take = 0;
		message.cs_release = 1;

		result = device->bus->ops->xfer(device, &message);
		if (result == 0)
		{
			result = -RT_EIO;
			goto __exit;
		}

		result = RT_EOK;
	}
	else
	{
		return -RT_EIO;
	}

__exit:
	rt_mutex_release(&(device->bus->lock));
	return result;
}

rt_size_t rt_spi_transfer(struct rt_spi_device* device, const void *send_buf,
		void* recv_buf, rt_size_t length)
{
	rt_err_t result;
	struct rt_spi_message message;

	RT_ASSERT(device != RT_NULL);
	RT_ASSERT(device->bus != RT_NULL);

	result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
	if (result == RT_EOK)
	{
		if (device->bus->owner != device)
		{
			/* not the same owner as current, re-configure SPI bus */
			result = device->bus->ops->configure(device, &device->config);
			if (result == RT_EOK)
			{
				/* set SPI bus owner */
				device->bus->owner = device;
			}
			else
			{
				/* configure SPI bus failed */
				rt_set_errno(-RT_EIO);
				result = 0;
				goto __exit;
			}
		}

		/* initial message */
		message.send_buf = send_buf;
		message.recv_buf = recv_buf;
		message.length = length;
		message.cs_take = message.cs_release = 1;

		/* transfer message */
		result = device->bus->ops->xfer(device, &message);
		if (result == 0)
		{
			rt_set_errno(-RT_EIO);
			goto __exit;
		}
	}
	else
	{
		rt_set_errno(-RT_EIO);
		return 0;
	}

__exit:
	rt_mutex_release(&(device->bus->lock));
	return result;
}