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spi: Fix the generic API

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- Add a spi_slave_select function for controllers supporting per-slave
  addressing
- Adding one full-duplex r/w function
- All r/w function go through one unique driver call
- Only one callback for all

Change-Id: Ie97e6a6119b2b34093598a8eb5dbfe0665bf08f3
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
This commit is contained in:
Tomasz Bursztyka 2015-08-21 12:48:54 +03:00 • committed by Anas Nashif
commit dd12326e86
1 changed files with 75 additions and 12 deletions
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87
include/spi.h
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@ -58,8 +58,14 @@ extern "C" {
#define SPI_WORD_SIZE_MASK (0xFF << 3)
#define SPI_WORD_SIZE_GET(_in_) ((_in_ & SPI_WORD_SIZE_MASK) >> 3)
enum spi_cb_type {
SPI_CB_WRITE = 1,
SPI_CB_READ = 2,
SPI_CB_TRANSCEIVE = 3
};
/* application callback function signature */
typedef void (*spi_callback)(struct device *dev);
typedef void (*spi_callback)(struct device *dev, enum spi_cb_type cb_type);
/*
* config is a bit field with the following parts:
@ -75,18 +81,20 @@ typedef void (*spi_callback)(struct device *dev);
struct spi_config {
uint32_t config;
uint32_t max_sys_freq;
spi_callback cb_receive;
spi_callback cb_transmit;
spi_callback callback;
};
typedef int (*spi_api_configure)(struct device *dev, struct spi_config *config);
typedef int (*spi_api_io)(struct device *dev, uint8_t *buf, uint32_t len);
typedef int (*spi_api_slave_select)(struct device *dev, uint32_t slave);
typedef int (*spi_api_io)(struct device *dev,
uint8_t *tx_buf, uint32_t tx_buf_len,
uint8_t *rx_buf, uint32_t rx_buf_len);
typedef int (*spi_api_control)(struct device *dev);
struct spi_driver_api {
spi_api_configure configure;
spi_api_io read;
spi_api_io write;
spi_api_slave_select slave_select;
spi_api_io transceive;
spi_api_control suspend;
spi_api_control resume;
};
@ -95,6 +103,8 @@ struct spi_driver_api {
* @brief Configure a host controller for operating against slaves
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to the application provided configuration
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_configure(struct device *dev, struct spi_config *config)
{
@ -102,33 +112,84 @@ inline int spi_configure(struct device *dev, struct spi_config *config)
return api->configure(dev, config);
}
/**
* @brief Select a slave to deal with.
*
* Note: This is meaningful only if the controller supports per-slave
* addressing (One SS line per-slave). If not, this will not have any effect
* and you will have to consider daisy-chaining to deal with multiple slave
* on the same line.
*
* @param dev Pointer to the device structure for the driver instance
* @param slave An integer identifying the slave
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_slave_select(struct device *dev, uint32_t slave)
{
struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;
if (!api->slave_select) {
return DEV_OK;
}
return api->slave_select(dev, slave);
}
/**
* @brief Read a defined amount of data from an SPI driver
* @param dev Pointer to the device structure for the driver instance
* @param buf Memory pool that data should be transferred to
* @param len Size of the memory pool available for writing to
* @param buf Memory buffer that data should be transferred to
* @param len Size of the memory buffer available for writing to
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_read(struct device *dev, uint8_t *buf, uint32_t len)
{
struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;
return api->read(dev, buf, len);
return api->transceive(dev, NULL, 0, buf, len);
}
/**
* @brief Write a defined amount of data through an SPI driver
* @param dev Pointer to the device structure for the driver instance
* @param buf Memory pool that data should be transferred from
* @param len Size of the memory pool available for reading from
* @param buf Memory buffer that data should be transferred from
* @param len Size of the memory buffer available for reading from
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_write(struct device *dev, uint8_t *buf, uint32_t len)
{
struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;
return api->write(dev, buf, len);
return api->transceive(dev, buf, len, NULL, 0);
}
/**
* @brief Read and write defined amount of data through an SPI driver
*
* Note: This is meant for full-duplex transmission.
*
* @param dev Pointer to the device structure for the driver instance
* @param tx_buf Memory buffer that data should be transferred from
* @param tx_len Size of the memory buffer available for reading from
* @param rx_buf Memory buffer that data should be transferred to
* @param rx_len Size of the memory buffer available for writing to
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_transceive(struct device *dev,
uint8_t *tx_buf, uint32_t tx_buf_len,
uint8_t *rx_buf, uint32_t rx_buf_len)
{
struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;
return api->transceive(dev, tx_buf, tx_buf_len, rx_buf, rx_buf_len);
}
/**
* @brief Suspend the SPI host controller operations
* @param dev Pointer to the device structure for the driver instance
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_suspend(struct device *dev)
{
@ -139,6 +200,8 @@ inline int spi_suspend(struct device *dev)
/**
* @brief Resume the SPI host controller operations
* @param dev Pointer to the device structure for the driver instance
*
* @return DEV_OK if successful, another DEV_* code otherwise.
*/
inline int spi_resume(struct device *dev)
{