Changed SPI message to message list. Added take/release SPI device/bus interface.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2123 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/include/drivers/spi.h

@@ -39,6 +39,7 @@ struct rt_spi_message
 	const void* send_buf;
 	void* recv_buf;
 	rt_size_t length;
+	struct rt_spi_message* next;
 
 	unsigned cs_take:1;
 	unsigned cs_release:1;
@@ -88,22 +89,81 @@ struct rt_spi_device
 #define SPI_DEVICE(dev)	((struct rt_spi_device*)(dev))
 
 /* register a SPI bus */
-rt_err_t rt_spi_bus_register(struct rt_spi_bus* bus, const char* name, const struct rt_spi_ops* ops);
+rt_err_t rt_spi_bus_register(struct rt_spi_bus* bus, const char* name,
+		const struct rt_spi_ops* ops);
 /* attach a device on SPI bus */
-rt_err_t rt_spi_bus_attach_device(struct rt_spi_device* device, const char* name, const char* bus_name, void* user_data);
+rt_err_t rt_spi_bus_attach_device(struct rt_spi_device* device, const char* name,
+		const char* bus_name, void* user_data);
+/**
+ * This function takes SPI bus.
+ *
+ * @param device the SPI device attached to SPI bus
+ *
+ * @return RT_EOK on taken SPI bus successfully. others on taken SPI bus failed.
+ */
+rt_err_t rt_spi_take_bus(struct rt_spi_device* device);
+/**
+ * This function releases SPI bus.
+ *
+ * @param device the SPI device attached to SPI bus
+ *
+ * @return RT_EOK on release SPI bus successfully.
+ */
+rt_err_t rt_spi_release_bus(struct rt_spi_device* device);
+
+/**
+ * This function take SPI device (takes CS of SPI device).
+ *
+ * @param device the SPI device attached to SPI bus
+ *
+ * @return RT_EOK on release SPI bus successfully. others on taken SPI bus failed.
+ */
+rt_err_t rt_spi_take(struct rt_spi_device* device);
+
+/**
+ * This function releases SPI device (releases CS of SPI device).
+ *
+ * @param device the SPI device attached to SPI bus
+ *
+ * @return RT_EOK on release SPI device successfully.
+ */
+rt_err_t rt_spi_release(struct rt_spi_device* device);
+
 /* set configuration on SPI device */
 rt_err_t rt_spi_configure(struct rt_spi_device* device, struct rt_spi_configuration* cfg);
 
-/* send data then receive data from SPI devicew */
+/* send data then receive data from SPI device */
 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 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);
 
+/**
+ * This function transmits data to SPI device.
+ *
+ * @param device the SPI device attached to SPI bus
+ * @param send_buf the buffer to be transmitted to SPI device.
+ * @param recv_buf the buffer to save received data from SPI device.
+ * @param length the length of transmitted data.
+ *
+ * @return the actual length of transmitted.
+ */
 rt_size_t rt_spi_transfer(struct rt_spi_device* device, const void *send_buf,
 		void* recv_buf, rt_size_t length);
 
+/**
+ * This function transfers a message list to the SPI device.
+ *
+ * @param device the SPI device attached to SPI bus
+ * @param message the message list to be transmitted to SPI device
+ *
+ * @return RT_NULL if transmits message list successfully,
+ *         SPI message which be transmitted failed.
+ */
+struct rt_spi_message *rt_spi_transfer_message(struct rt_spi_device* device,
+		struct rt_spi_message *message);
+
 rt_inline rt_size_t rt_spi_recv(struct rt_spi_device* device, void* recv_buf, rt_size_t length)
 {
 	return rt_spi_transfer(device, RT_NULL, recv_buf, length);
@@ -130,4 +190,24 @@ rt_inline rt_uint16_t rt_spi_sendrecv16(struct rt_spi_device* device, rt_uint16_
 	return value;
 }
 
+/**
+ * This function appends a message to the SPI message list.
+ *
+ * @param list the SPI message list header.
+ * @param message the message pointer to be appended to the message list.
+ */
+rt_inline void rt_spi_message_append(struct rt_spi_message* list, struct rt_spi_message* message)
+{
+	RT_ASSERT(list != RT_NULL);
+	if (message == RT_NULL) return; /* not append */
+
+	while (list->next != RT_NULL)
+	{
+		list = list->next;
+	}
+
+	list->next = message;
+	message->next = RT_NULL;
+}
+
 #endif

components/drivers/spi/spi_core.c

@@ -111,6 +111,7 @@ rt_err_t rt_spi_send_then_send(struct rt_spi_device* device, const void *send_bu
 		message.length = send_length1;
 		message.cs_take = 1;
 		message.cs_release = 0;
+		message.next = RT_NULL;
 
 		result = device->bus->ops->xfer(device, &message);
 		if (result == 0)
@@ -125,6 +126,7 @@ rt_err_t rt_spi_send_then_send(struct rt_spi_device* device, const void *send_bu
 		message.length = send_length2;
 		message.cs_take = 0;
 		message.cs_release = 1;
+		message.next = RT_NULL;
 
 		result = device->bus->ops->xfer(device, &message);
 		if (result == 0)
@@ -180,6 +182,7 @@ rt_err_t rt_spi_send_then_recv(struct rt_spi_device* device, const void *send_bu
 		message.length = send_length;
 		message.cs_take = 1;
 		message.cs_release = 0;
+		message.next = RT_NULL;
 
 		result = device->bus->ops->xfer(device, &message);
 		if (result == 0)
@@ -194,6 +197,7 @@ rt_err_t rt_spi_send_then_recv(struct rt_spi_device* device, const void *send_bu
 		message.length = recv_length;
 		message.cs_take = 0;
 		message.cs_release = 1;
+		message.next = RT_NULL;
 
 		result = device->bus->ops->xfer(device, &message);
 		if (result == 0)
@@ -249,6 +253,7 @@ rt_size_t rt_spi_transfer(struct rt_spi_device* device, const void *send_buf,
 		message.recv_buf = recv_buf;
 		message.length = length;
 		message.cs_take = message.cs_release = 1;
+		message.next = RT_NULL;
 
 		/* transfer message */
 		result = device->bus->ops->xfer(device, &message);
@@ -268,3 +273,147 @@ __exit:
 	rt_mutex_release(&(device->bus->lock));
 	return result;
 }
+
+struct rt_spi_message *rt_spi_transfer_message(struct rt_spi_device* device,
+		struct rt_spi_message *message)
+{
+	rt_err_t result;
+	struct rt_spi_message* index;
+
+	RT_ASSERT(device != RT_NULL);
+
+	/* get first message */
+	index = message;
+	if (index == RT_NULL) return index;
+
+	result = rt_mutex_take(&(device->bus->lock), RT_WAITING_FOREVER);
+	if (result != RT_EOK)
+	{
+		rt_set_errno(-RT_EBUSY);
+		return index;
+	}
+
+	/* reset errno */
+	rt_set_errno(RT_EOK);
+
+	/* configure SPI bus */
+	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;
+		}
+	}
+
+	/* transmit each SPI message */
+	while (index != RT_NULL)
+	{
+		/* transmit SPI message */
+		result = device->bus->ops->xfer(device, index);
+		if (result == 0)
+		{
+			rt_set_errno(-RT_EIO);
+			break;
+		}
+
+		index = index->next;
+	}
+
+__exit:
+	/* release bus lock */
+	rt_mutex_release(&(device->bus->lock));
+	return index;
+}
+
+rt_err_t rt_spi_take_bus(struct rt_spi_device* device)
+{
+	rt_err_t result = RT_EOK;
+
+	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)
+	{
+		rt_set_errno(-RT_EBUSY);
+		return -RT_EBUSY;
+	}
+
+	/* reset errno */
+	rt_set_errno(RT_EOK);
+
+	/* configure SPI bus */
+	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);
+			/* release lock */
+			rt_mutex_release(&(device->bus->lock));
+
+			return -RT_EIO;
+		}
+	}
+
+	return result;
+}
+
+rt_err_t rt_spi_release_bus(struct rt_spi_device* device)
+{
+	RT_ASSERT(device != RT_NULL);
+	RT_ASSERT(device->bus != RT_NULL);
+	RT_ASSERT(device->bus->owner != device);
+
+	/* release lock */
+	rt_mutex_release(&(device->bus->lock));
+
+	return RT_EOK;
+}
+
+rt_err_t rt_spi_take(struct rt_spi_device* device)
+{
+	rt_err_t result;
+	struct rt_spi_message message;
+
+	RT_ASSERT(device != RT_NULL);
+	RT_ASSERT(device->bus != RT_NULL);
+
+	rt_memset(&message, 0, sizeof(message));
+	message.cs_take = 1;
+
+	result = device->bus->ops->xfer(device, &message);
+	return result;
+}
+
+rt_err_t rt_spi_release(struct rt_spi_device* device)
+{
+	rt_err_t result;
+	struct rt_spi_message message;
+
+	RT_ASSERT(device != RT_NULL);
+	RT_ASSERT(device->bus != RT_NULL);
+
+	rt_memset(&message, 0, sizeof(message));
+	message.cs_release = 1;
+
+	result = device->bus->ops->xfer(device, &message);
+	return result;
+}