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/****************************************************************************
* arch/arm/src/stm32l4/stm32l4_spi.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* The external functions, stm32l4_spi1/2/3select and stm32l4_spi1/2/3status
* must be provided by board-specific logic. They are implementations of the
* select and status methods of the SPI interface defined by struct spi_ops_s
* (see include/nuttx/spi/spi.h). All other methods (including
* stm32l4_spibus_initialize()) are provided by common STM32 logic. To use
* this common SPI logic on your board:
*
* 1. Provide logic in stm32l4_board_initialize() to configure SPI chip
* select pins.
* 2. Provide stm32l4_spi1/2/3select() and stm32l4_spi1/2/3status()
* functions in your board-specific logic. These functions will perform
* chip selection and status operations using GPIOs in the way your
* board is configured.
* 3. Add a calls to stm32l4_spibus_initialize() in your low level
* application initialization logic
* 4. The handle returned by stm32l4_spibus_initialize() may then be used
* to bind the SPI driver to higher level logic (e.g., calling
* mmcsd_spislotinitialize(), for example, will bind the SPI driver to
* the SPI MMC/SD driver).
*
****************************************************************************/
/* This driver is ported from the stm32 one, which only supports 8 and 16
* bits transfers. The STM32L4 family supports frame size from 4 to 16 bits,
* but we do not support that yet. For the moment, we replace uses of the
* CR1_DFF bit with a check of the CR2_DS[0..3] bits. If the value is
* SPI_CR2_DS_16BIT it means 16 bits, else 8 bits.
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/mutex.h>
#include <nuttx/spi/spi.h>
#include <nuttx/power/pm.h>
#include "arm_internal.h"
#include "chip.h"
#include "stm32l4.h"
#include "stm32l4_gpio.h"
#include "stm32l4_dma.h"
#include "stm32l4_spi.h"
#include <arch/board/board.h>
#if defined(CONFIG_STM32L4_SPI1) || defined(CONFIG_STM32L4_SPI2) || \
defined(CONFIG_STM32L4_SPI3)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* SPI interrupts */
#ifdef CONFIG_STM32L4_SPI_INTERRUPTS
# error "Interrupt driven SPI not yet supported"
#endif
/* Can't have both interrupt driven SPI and SPI DMA */
#if defined(CONFIG_STM32L4_SPI_INTERRUPTS) && defined(CONFIG_STM32L4_SPI_DMA)
# error "Cannot enable both interrupt mode and DMA mode for SPI"
#endif
/* SPI DMA priority */
#ifdef CONFIG_STM32L4_SPI_DMA
# if defined(CONFIG_SPI_DMAPRIO)
# define SPI_DMA_PRIO CONFIG_SPI_DMAPRIO
# else
# define SPI_DMA_PRIO DMA_CCR_PRIMED
# endif
# if (SPI_DMA_PRIO & ~DMA_CCR_PL_MASK) != 0
# error "Illegal value for CONFIG_SPI_DMAPRIO"
# endif
#endif
/* DMA channel configuration */
#define SPI_RXDMA16_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_16BITS|DMA_CCR_PSIZE_16BITS|DMA_CCR_MINC )
#define SPI_RXDMA8_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_8BITS |DMA_CCR_MINC )
#define SPI_RXDMA16NULL_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_16BITS )
#define SPI_RXDMA8NULL_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_8BITS )
#define SPI_TXDMA16_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_16BITS|DMA_CCR_PSIZE_16BITS|DMA_CCR_MINC|DMA_CCR_DIR)
#define SPI_TXDMA8_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_8BITS |DMA_CCR_MINC|DMA_CCR_DIR)
#define SPI_TXDMA16NULL_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_16BITS |DMA_CCR_DIR)
#define SPI_TXDMA8NULL_CONFIG (SPI_DMA_PRIO|DMA_CCR_MSIZE_8BITS |DMA_CCR_PSIZE_8BITS |DMA_CCR_DIR)
/****************************************************************************
* Private Types
****************************************************************************/
struct stm32l4_spidev_s
{
struct spi_dev_s spidev; /* Externally visible part of the SPI interface */
uint32_t spibase; /* SPIn base address */
uint32_t spiclock; /* Clocking for the SPI module */
#ifdef CONFIG_STM32L4_SPI_INTERRUPTS
uint8_t spiirq; /* SPI IRQ number */
#endif
#ifdef CONFIG_STM32L4_SPI_DMA
volatile uint8_t rxresult; /* Result of the RX DMA */
volatile uint8_t txresult; /* Result of the RX DMA */
#ifdef CONFIG_SPI_TRIGGER
bool defertrig; /* Flag indicating that trigger should be deferred */
bool trigarmed; /* Flag indicating that the trigger is armed */
#endif
uint16_t rxch; /* The RX DMA channel number */
uint16_t txch; /* The TX DMA channel number */
DMA_HANDLE rxdma; /* DMA channel handle for RX transfers */
DMA_HANDLE txdma; /* DMA channel handle for TX transfers */
sem_t rxsem; /* Wait for RX DMA to complete */
sem_t txsem; /* Wait for TX DMA to complete */
uint32_t txccr; /* DMA control register for TX transfers */
uint32_t rxccr; /* DMA control register for RX transfers */
#endif
bool initialized; /* Has SPI interface been initialized */
mutex_t lock; /* Held while chip is selected for mutual exclusion */
uint32_t frequency; /* Requested clock frequency */
uint32_t actual; /* Actual clock frequency */
uint8_t nbits; /* Width of word in bits (4 through 16) */
uint8_t mode; /* Mode 0,1,2,3 */
#ifdef CONFIG_PM
struct pm_callback_s pm_cb; /* PM callbacks */
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Helpers */
static inline uint16_t spi_getreg(struct stm32l4_spidev_s *priv,
uint8_t offset);
static inline void spi_putreg(struct stm32l4_spidev_s *priv,
uint8_t offset,
uint16_t value);
static inline uint16_t spi_readword(struct stm32l4_spidev_s *priv);
static inline void spi_writeword(struct stm32l4_spidev_s *priv,
uint16_t byte);
static inline bool spi_16bitmode(struct stm32l4_spidev_s *priv);
/* DMA support */
#ifdef CONFIG_STM32L4_SPI_DMA
static int spi_dmarxwait(struct stm32l4_spidev_s *priv);
static int spi_dmatxwait(struct stm32l4_spidev_s *priv);
static inline void spi_dmarxwakeup(struct stm32l4_spidev_s *priv);
static inline void spi_dmatxwakeup(struct stm32l4_spidev_s *priv);
static void spi_dmarxcallback(DMA_HANDLE handle, uint8_t isr,
void *arg);
static void spi_dmatxcallback(DMA_HANDLE handle, uint8_t isr,
void *arg);
static void spi_dmarxsetup(struct stm32l4_spidev_s *priv,
void *rxbuffer,
void *rxdummy,
size_t nwords);
static void spi_dmatxsetup(struct stm32l4_spidev_s *priv,
const void *txbuffer,
const void *txdummy,
size_t nwords);
static inline void spi_dmarxstart(struct stm32l4_spidev_s *priv);
static inline void spi_dmatxstart(struct stm32l4_spidev_s *priv);
#endif
/* SPI methods */
static int spi_lock(struct spi_dev_s *dev, bool lock);
static uint32_t spi_setfrequency(struct spi_dev_s *dev,
uint32_t frequency);
static void spi_setmode(struct spi_dev_s *dev,
enum spi_mode_e mode);
static void spi_setbits(struct spi_dev_s *dev, int nbits);
#ifdef CONFIG_SPI_HWFEATURES
static int spi_hwfeatures(struct spi_dev_s *dev,
spi_hwfeatures_t features);
#endif
static uint32_t spi_send(struct spi_dev_s *dev, uint32_t wd);
static void spi_exchange(struct spi_dev_s *dev,
const void *txbuffer, void *rxbuffer,
size_t nwords);
#ifdef CONFIG_SPI_TRIGGER
static int spi_trigger(struct spi_dev_s *dev);
#endif
#ifndef CONFIG_SPI_EXCHANGE
static void spi_sndblock(struct spi_dev_s *dev,
const void *txbuffer, size_t nwords);
static void spi_recvblock(struct spi_dev_s *dev,
void *rxbuffer, size_t nwords);
#endif
/* Initialization */
static void spi_bus_initialize(struct stm32l4_spidev_s *priv);
/* PM interface */
#ifdef CONFIG_PM
static int spi_pm_prepare(struct pm_callback_s *cb, int domain,
enum pm_state_e pmstate);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI1
static const struct spi_ops_s g_spi1ops =
{
.lock = spi_lock,
.select = stm32l4_spi1select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
#ifdef CONFIG_SPI_HWFEATURES
.hwfeatures = spi_hwfeatures,
#endif
.status = stm32l4_spi1status,
#ifdef CONFIG_SPI_CMDDATA
.cmddata = stm32l4_spi1cmddata,
#endif
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
#ifdef CONFIG_SPI_TRIGGER
.trigger = spi_trigger,
#endif
#ifdef CONFIG_SPI_CALLBACK
.registercallback = stm32l4_spi1register, /* Provided externally */
#else
.registercallback = 0, /* Not implemented */
#endif
};
static struct stm32l4_spidev_s g_spi1dev =
{
.spidev =
{
.ops = &g_spi1ops,
},
.spibase = STM32L4_SPI1_BASE,
.spiclock = STM32L4_PCLK2_FREQUENCY,
#ifdef CONFIG_STM32L4_SPI_INTERRUPTS
.spiirq = STM32L4_IRQ_SPI1,
#endif
#ifdef CONFIG_STM32L4_SPI_DMA
/* lines must be configured in board.h */
.rxch = DMACHAN_SPI1_RX,
.txch = DMACHAN_SPI1_TX,
.rxsem = SEM_INITIALIZER(0),
.txsem = SEM_INITIALIZER(0),
#endif
.lock = NXMUTEX_INITIALIZER,
#ifdef CONFIG_PM
.pm_cb.prepare = spi_pm_prepare,
#endif
};
#endif
#ifdef CONFIG_STM32L4_SPI2
static const struct spi_ops_s g_spi2ops =
{
.lock = spi_lock,
.select = stm32l4_spi2select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
#ifdef CONFIG_SPI_HWFEATURES
.hwfeatures = spi_hwfeatures,
#endif
.status = stm32l4_spi2status,
#ifdef CONFIG_SPI_CMDDATA
.cmddata = stm32l4_spi2cmddata,
#endif
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
#ifdef CONFIG_SPI_TRIGGER
.trigger = spi_trigger,
#endif
#ifdef CONFIG_SPI_CALLBACK
.registercallback = stm32l4_spi2register, /* provided externally */
#else
.registercallback = 0, /* not implemented */
#endif
};
static struct stm32l4_spidev_s g_spi2dev =
{
.spidev =
{
.ops = &g_spi2ops,
},
.spibase = STM32L4_SPI2_BASE,
.spiclock = STM32L4_PCLK1_FREQUENCY,
#ifdef CONFIG_STM32L4_SPI_INTERRUPTS
.spiirq = STM32L4_IRQ_SPI2,
#endif
#ifdef CONFIG_STM32L4_SPI_DMA
.rxch = DMACHAN_SPI2_RX,
.txch = DMACHAN_SPI2_TX,
.rxsem = SEM_INITIALIZER(0),
.txsem = SEM_INITIALIZER(0),
#endif
.lock = NXMUTEX_INITIALIZER,
#ifdef CONFIG_PM
.pm_cb.prepare = spi_pm_prepare,
#endif
};
#endif
#ifdef CONFIG_STM32L4_SPI3
static const struct spi_ops_s g_spi3ops =
{
.lock = spi_lock,
.select = stm32l4_spi3select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
#ifdef CONFIG_SPI_HWFEATURES
.hwfeatures = spi_hwfeatures,
#endif
.status = stm32l4_spi3status,
#ifdef CONFIG_SPI_CMDDATA
.cmddata = stm32l4_spi3cmddata,
#endif
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
#ifdef CONFIG_SPI_TRIGGER
.trigger = spi_trigger,
#endif
#ifdef CONFIG_SPI_CALLBACK
.registercallback = stm32l4_spi3register, /* provided externally */
#else
.registercallback = 0, /* not implemented */
#endif
};
static struct stm32l4_spidev_s g_spi3dev =
{
.spidev =
{
.ops = &g_spi3ops,
},
.spibase = STM32L4_SPI3_BASE,
.spiclock = STM32L4_PCLK1_FREQUENCY,
#ifdef CONFIG_STM32L4_SPI_INTERRUPTS
.spiirq = STM32L4_IRQ_SPI3,
#endif
#ifdef CONFIG_STM32L4_SPI_DMA
.rxch = DMACHAN_SPI3_RX,
.txch = DMACHAN_SPI3_TX,
.rxsem = SEM_INITIALIZER(0),
.txsem = SEM_INITIALIZER(0),
#endif
.lock = NXMUTEX_INITIALIZER,
#ifdef CONFIG_PM
.pm_cb.prepare = spi_pm_prepare,
#endif
};
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: spi_getreg
*
* Description:
* Get the contents of the SPI register at offset
*
* Input Parameters:
* priv - private SPI device structure
* offset - offset to the register of interest
*
* Returned Value:
* The contents of the 16-bit register
*
****************************************************************************/
static inline uint16_t spi_getreg(struct stm32l4_spidev_s *priv,
uint8_t offset)
{
return getreg16(priv->spibase + offset);
}
/****************************************************************************
* Name: spi_putreg
*
* Description:
* Write a 16-bit value to the SPI register at offset
*
* Input Parameters:
* priv - private SPI device structure
* offset - offset to the register of interest
* value - the 16-bit value to be written
*
* Returned Value:
* The contents of the 16-bit register
*
****************************************************************************/
static inline void spi_putreg(struct stm32l4_spidev_s *priv,
uint8_t offset, uint16_t value)
{
putreg16(value, priv->spibase + offset);
}
/****************************************************************************
* Name: spi_getreg8
*
* Description:
* Get the contents of the SPI register at offset
*
* Input Parameters:
* priv - private SPI device structure
* offset - offset to the register of interest
*
* Returned Value:
* The contents of the 8-bit register
*
****************************************************************************/
static inline uint8_t spi_getreg8(struct stm32l4_spidev_s *priv,
uint8_t offset)
{
return getreg8(priv->spibase + offset);
}
/****************************************************************************
* Name: spi_putreg8
*
* Description:
* Write a 8-bit value to the SPI register at offset
*
* Input Parameters:
* priv - private SPI device structure
* offset - offset to the register of interest
* value - the 8-bit value to be written
*
****************************************************************************/
static inline void spi_putreg8(struct stm32l4_spidev_s *priv,
uint8_t offset, uint8_t value)
{
putreg8(value, priv->spibase + offset);
}
/****************************************************************************
* Name: spi_readword
*
* Description:
* Read one word (TWO bytes!) from SPI
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* Word as read
*
****************************************************************************/
static inline uint16_t spi_readword(struct stm32l4_spidev_s *priv)
{
/* Wait until the receive buffer is not empty */
while ((spi_getreg(priv, STM32L4_SPI_SR_OFFSET) & SPI_SR_RXNE) == 0);
/* Then return the received byte */
return spi_getreg(priv, STM32L4_SPI_DR_OFFSET);
}
/****************************************************************************
* Name: spi_readbyte
*
* Description:
* Read one byte from SPI
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* Byte as read
*
****************************************************************************/
static inline uint8_t spi_readbyte(struct stm32l4_spidev_s *priv)
{
/* Wait until the receive buffer is not empty */
while ((spi_getreg(priv, STM32L4_SPI_SR_OFFSET) & SPI_SR_RXNE) == 0);
/* Then return the received byte */
return spi_getreg8(priv, STM32L4_SPI_DR_OFFSET);
}
/****************************************************************************
* Name: spi_writeword
*
* Description:
* Write one 16-bit frame to the SPI FIFO
*
* Input Parameters:
* priv - Device-specific state data
* byte - Word to send
*
* Returned Value:
* None
*
****************************************************************************/
static inline void spi_writeword(struct stm32l4_spidev_s *priv,
uint16_t word)
{
/* Wait until the transmit buffer is empty */
while ((spi_getreg(priv, STM32L4_SPI_SR_OFFSET) & SPI_SR_TXE) == 0);
/* Then send the byte */
spi_putreg(priv, STM32L4_SPI_DR_OFFSET, word);
}
/****************************************************************************
* Name: spi_writebyte
*
* Description:
* Write one 8-bit frame to the SPI FIFO
*
* Input Parameters:
* priv - Device-specific state data
* byte - Byte to send
*
* Returned Value:
* None
*
****************************************************************************/
static inline void spi_writebyte(struct stm32l4_spidev_s *priv,
uint8_t byte)
{
/* Wait until the transmit buffer is empty */
while ((spi_getreg(priv, STM32L4_SPI_SR_OFFSET) & SPI_SR_TXE) == 0);
/* Then send the byte */
spi_putreg8(priv, STM32L4_SPI_DR_OFFSET, byte);
}
/****************************************************************************
* Name: spi_16bitmode
*
* Description:
* Check if the SPI is operating in 16-bit mode
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* true: 16-bit mode, false: 8-bit mode
*
****************************************************************************/
static inline bool spi_16bitmode(struct stm32l4_spidev_s *priv)
{
return (priv->nbits > 8);
}
/****************************************************************************
* Name: spi_dmarxwaitw
*
* Description:
* Wait for DMA to complete.
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static int spi_dmarxwait(struct stm32l4_spidev_s *priv)
{
int ret;
/* Take the semaphore (perhaps waiting). If the result is zero, then the
* DMA must not really have completed???
*/
do
{
ret = nxsem_wait_uninterruptible(&priv->rxsem);
/* The only expected error is ECANCELED which would occur if the
* calling thread were canceled.
*/
DEBUGASSERT(ret == OK || ret == -ECANCELED);
}
while (priv->rxresult == 0 && ret == OK);
return ret;
}
#endif
/****************************************************************************
* Name: spi_dmatxwait
*
* Description:
* Wait for DMA to complete.
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static int spi_dmatxwait(struct stm32l4_spidev_s *priv)
{
int ret;
/* Take the semaphore (perhaps waiting). If the result is zero, then the
* DMA must not really have completed???
*/
do
{
ret = nxsem_wait_uninterruptible(&priv->txsem);
/* The only expected error is ECANCELED which would occur if the
* calling thread were canceled.
*/
DEBUGASSERT(ret == OK || ret == -ECANCELED);
}
while (priv->txresult == 0 && ret == OK);
return ret;
}
#endif
/****************************************************************************
* Name: spi_dmarxwakeup
*
* Description:
* Signal that DMA is complete
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static inline void spi_dmarxwakeup(struct stm32l4_spidev_s *priv)
{
nxsem_post(&priv->rxsem);
}
#endif
/****************************************************************************
* Name: spi_dmatxwakeup
*
* Description:
* Signal that DMA is complete
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static inline void spi_dmatxwakeup(struct stm32l4_spidev_s *priv)
{
nxsem_post(&priv->txsem);
}
#endif
/****************************************************************************
* Name: spi_dmarxcallback
*
* Description:
* Called when the RX DMA completes
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static void spi_dmarxcallback(DMA_HANDLE handle, uint8_t isr, void *arg)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)arg;
/* Wake-up the SPI driver */
priv->rxresult = isr | 0x080; /* OR'ed with 0x80 to assure non-zero */
spi_dmarxwakeup(priv);
}
#endif
/****************************************************************************
* Name: spi_dmatxcallback
*
* Description:
* Called when the RX DMA completes
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static void spi_dmatxcallback(DMA_HANDLE handle, uint8_t isr, void *arg)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)arg;
/* Wake-up the SPI driver */
priv->txresult = isr | 0x080; /* OR'ed with 0x80 to assure non-zero */
spi_dmatxwakeup(priv);
}
#endif
/****************************************************************************
* Name: spi_dmarxsetup
*
* Description:
* Setup to perform RX DMA
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static void spi_dmarxsetup(struct stm32l4_spidev_s *priv,
void *rxbuffer, void *rxdummy,
size_t nwords)
{
/* 8- or 16-bit mode? */
if (spi_16bitmode(priv))
{
/* 16-bit mode -- is there a buffer to receive data in? */
if (rxbuffer)
{
priv->rxccr = SPI_RXDMA16_CONFIG;
}
else
{
rxbuffer = rxdummy;
priv->rxccr = SPI_RXDMA16NULL_CONFIG;
}
}
else
{
/* 8-bit mode -- is there a buffer to receive data in? */
if (rxbuffer)
{
priv->rxccr = SPI_RXDMA8_CONFIG;
}
else
{
rxbuffer = rxdummy;
priv->rxccr = SPI_RXDMA8NULL_CONFIG;
}
}
/* Configure the RX DMA */
stm32l4_dmasetup(priv->rxdma, priv->spibase + STM32L4_SPI_DR_OFFSET,
(uint32_t)rxbuffer, nwords, priv->rxccr);
}
#endif
/****************************************************************************
* Name: spi_dmatxsetup
*
* Description:
* Setup to perform TX DMA
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static void spi_dmatxsetup(struct stm32l4_spidev_s *priv,
const void *txbuffer,
const void *txdummy,
size_t nwords)
{
/* 8- or 16-bit mode? */
if (spi_16bitmode(priv))
{
/* 16-bit mode -- is there a buffer to transfer data from? */
if (txbuffer)
{
priv->txccr = SPI_TXDMA16_CONFIG;
}
else
{
txbuffer = txdummy;
priv->txccr = SPI_TXDMA16NULL_CONFIG;
}
}
else
{
/* 8-bit mode -- is there a buffer to transfer data from? */
if (txbuffer)
{
priv->txccr = SPI_TXDMA8_CONFIG;
}
else
{
txbuffer = txdummy;
priv->txccr = SPI_TXDMA8NULL_CONFIG;
}
}
/* Setup the TX DMA */
stm32l4_dmasetup(priv->txdma, priv->spibase + STM32L4_SPI_DR_OFFSET,
(uint32_t)txbuffer, nwords, priv->txccr);
}
#endif
/****************************************************************************
* Name: spi_dmarxstart
*
* Description:
* Start RX DMA
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static inline void spi_dmarxstart(struct stm32l4_spidev_s *priv)
{
priv->rxresult = 0;
stm32l4_dmastart(priv->rxdma, spi_dmarxcallback, priv, false);
}
#endif
/****************************************************************************
* Name: spi_dmatxstart
*
* Description:
* Start TX DMA
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static inline void spi_dmatxstart(struct stm32l4_spidev_s *priv)
{
priv->txresult = 0;
stm32l4_dmastart(priv->txdma, spi_dmatxcallback, priv, false);
}
#endif
/****************************************************************************
* Name: spi_modifycr
*
* Description:
* Clear and set bits in the CR1 or CR2 register
*
* Input Parameters:
* priv - Device-specific state data
* clrbits - The bits to clear
* setbits - The bits to set
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_modifycr(uint32_t addr, struct stm32l4_spidev_s *priv,
uint16_t setbits, uint16_t clrbits)
{
uint16_t cr;
cr = spi_getreg(priv, addr);
cr &= ~clrbits;
cr |= setbits;
spi_putreg(priv, addr, cr);
}
/****************************************************************************
* Name: spi_lock
*
* Description:
* On SPI buses where there are multiple devices, it will be necessary to
* lock SPI to have exclusive access to the buses for a sequence of
* transfers. The bus should be locked before the chip is selected. After
* locking the SPI bus, the caller should then also call the setfrequency,
* setbits, and setmode methods to make sure that the SPI is properly
* configured for the device. If the SPI bus is being shared, then it
* may have been left in an incompatible state.
*
* Input Parameters:
* dev - Device-specific state data
* lock - true: Lock spi bus, false: unlock SPI bus
*
* Returned Value:
* None
*
****************************************************************************/
static int spi_lock(struct spi_dev_s *dev, bool lock)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
int ret;
if (lock)
{
ret = nxmutex_lock(&priv->lock);
}
else
{
ret = nxmutex_unlock(&priv->lock);
}
return ret;
}
/****************************************************************************
* Name: spi_setfrequency
*
* Description:
* Set the SPI frequency.
*
* Input Parameters:
* dev - Device-specific state data
* frequency - The SPI frequency requested
*
* Returned Value:
* Returns the actual frequency selected
*
****************************************************************************/
static uint32_t spi_setfrequency(struct spi_dev_s *dev,
uint32_t frequency)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
uint16_t setbits;
uint32_t actual;
/* Limit to max possible (if STM32L4_SPI_CLK_MAX is defined in board.h) */
if (frequency > STM32L4_SPI_CLK_MAX)
{
frequency = STM32L4_SPI_CLK_MAX;
}
/* Has the frequency changed? */
if (frequency != priv->frequency)
{
/* Choices are limited by PCLK frequency with a set of divisors */
if (frequency >= priv->spiclock >> 1)
{
/* More than fPCLK/2. This is as fast as we can go */
setbits = SPI_CR1_FPCLCKd2; /* 000: fPCLK/2 */
actual = priv->spiclock >> 1;
}
else if (frequency >= priv->spiclock >> 2)
{
/* Between fPCLCK/2 and fPCLCK/4, pick the slower */
setbits = SPI_CR1_FPCLCKd4; /* 001: fPCLK/4 */
actual = priv->spiclock >> 2;
}
else if (frequency >= priv->spiclock >> 3)
{
/* Between fPCLCK/4 and fPCLCK/8, pick the slower */
setbits = SPI_CR1_FPCLCKd8; /* 010: fPCLK/8 */
actual = priv->spiclock >> 3;
}
else if (frequency >= priv->spiclock >> 4)
{
/* Between fPCLCK/8 and fPCLCK/16, pick the slower */
setbits = SPI_CR1_FPCLCKd16; /* 011: fPCLK/16 */
actual = priv->spiclock >> 4;
}
else if (frequency >= priv->spiclock >> 5)
{
/* Between fPCLCK/16 and fPCLCK/32, pick the slower */
setbits = SPI_CR1_FPCLCKd32; /* 100: fPCLK/32 */
actual = priv->spiclock >> 5;
}
else if (frequency >= priv->spiclock >> 6)
{
/* Between fPCLCK/32 and fPCLCK/64, pick the slower */
setbits = SPI_CR1_FPCLCKd64; /* 101: fPCLK/64 */
actual = priv->spiclock >> 6;
}
else if (frequency >= priv->spiclock >> 7)
{
/* Between fPCLCK/64 and fPCLCK/128, pick the slower */
setbits = SPI_CR1_FPCLCKd128; /* 110: fPCLK/128 */
actual = priv->spiclock >> 7;
}
else
{
/* Less than fPCLK/128. This is as slow as we can go */
setbits = SPI_CR1_FPCLCKd256; /* 111: fPCLK/256 */
actual = priv->spiclock >> 8;
}
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, 0, SPI_CR1_SPE);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, setbits, SPI_CR1_BR_MASK);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, SPI_CR1_SPE, 0);
/* Save the frequency selection so that subsequent reconfigurations
* will be faster.
*/
spiinfo("Frequency %" PRId32 "->%" PRId32 "\n", frequency, actual);
priv->frequency = frequency;
priv->actual = actual;
}
return priv->actual;
}
/****************************************************************************
* Name: spi_setmode
*
* Description:
* Set the SPI mode. see enum spi_mode_e for mode definitions
*
* Input Parameters:
* dev - Device-specific state data
* mode - The SPI mode requested
*
* Returned Value:
* Returns the actual frequency selected
*
****************************************************************************/
static void spi_setmode(struct spi_dev_s *dev, enum spi_mode_e mode)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
uint16_t setbits;
uint16_t clrbits;
spiinfo("mode=%d\n", mode);
/* Has the mode changed? */
if (mode != priv->mode)
{
/* Yes... Set CR1 appropriately */
switch (mode)
{
case SPIDEV_MODE0: /* CPOL=0; CPHA=0 */
setbits = 0;
clrbits = SPI_CR1_CPOL | SPI_CR1_CPHA;
break;
case SPIDEV_MODE1: /* CPOL=0; CPHA=1 */
setbits = SPI_CR1_CPHA;
clrbits = SPI_CR1_CPOL;
break;
case SPIDEV_MODE2: /* CPOL=1; CPHA=0 */
setbits = SPI_CR1_CPOL;
clrbits = SPI_CR1_CPHA;
break;
case SPIDEV_MODE3: /* CPOL=1; CPHA=1 */
setbits = SPI_CR1_CPOL | SPI_CR1_CPHA;
clrbits = 0;
break;
default:
return;
}
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, 0, SPI_CR1_SPE);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, setbits, clrbits);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, SPI_CR1_SPE, 0);
/* Save the mode so that subsequent re-configurations will be
* faster.
*/
priv->mode = mode;
}
}
/****************************************************************************
* Name: spi_setbits
*
* Description:
* Set the number of bits per word. With STM32L4, this is not restricted to
* 8 or 16, but can be any value between 4 and 16.
*
* Input Parameters:
* dev - Device-specific state data
* nbits - The number of bits requested, negative value means LSB first.
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_setbits(struct spi_dev_s *dev, int nbits)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
uint16_t setbits;
uint16_t clrbits;
spiinfo("nbits=%d\n", nbits);
/* Has the number of bits changed? */
if (nbits != priv->nbits)
{
/* Yes... Set CR2 appropriately */
/* Set the number of bits (valid range 4-16) */
if (nbits < 4 || nbits > 16)
{
spierr("ERROR: nbits out of range: %d\n", nbits);
return;
}
clrbits = SPI_CR2_DS_MASK;
setbits = SPI_CR2_DS_VAL(nbits);
/* If nbits is <=8, then we are in byte mode and FRXTH shall be set
* (else, transaction will not complete).
*/
if (nbits < 9)
{
setbits |= SPI_CR2_FRXTH; /* RX FIFO Threshold = 1 byte */
}
else
{
clrbits |= SPI_CR2_FRXTH; /* RX FIFO Threshold = 2 bytes */
}
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, 0, SPI_CR1_SPE);
spi_modifycr(STM32L4_SPI_CR2_OFFSET, priv, setbits, clrbits);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, SPI_CR1_SPE, 0);
/* Save the selection so that subsequent re-configurations will be
* faster.
*/
priv->nbits = nbits;
}
}
/****************************************************************************
* Name: spi_hwfeatures
*
* Description:
* Set hardware-specific feature flags.
*
* Input Parameters:
* dev - Device-specific state data
* features - H/W feature flags
*
* Returned Value:
* Zero (OK) if the selected H/W features are enabled; A negated errno
* value if any H/W feature is not supportable.
*
****************************************************************************/
#ifdef CONFIG_SPI_HWFEATURES
static int spi_hwfeatures(struct spi_dev_s *dev,
spi_hwfeatures_t features)
{
#if defined(CONFIG_SPI_BITORDER) || defined(CONFIG_SPI_TRIGGER)
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
#endif
#ifdef CONFIG_SPI_BITORDER
uint16_t setbits;
uint16_t clrbits;
spiinfo("features=%08x\n", features);
/* Transfer data LSB first? */
if ((features & HWFEAT_LSBFIRST) != 0)
{
setbits = SPI_CR1_LSBFIRST;
clrbits = 0;
}
else
{
setbits = 0;
clrbits = SPI_CR1_LSBFIRST;
}
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, 0, SPI_CR1_SPE);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, setbits, clrbits);
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, SPI_CR1_SPE, 0);
features &= ~HWFEAT_LSBFIRST;
#endif
#ifdef CONFIG_SPI_TRIGGER
/* Turn deferred trigger mode on or off. Only applicable for DMA mode. If a
* transfer is deferred then the DMA will not actually be triggered until a
* subsequent call to SPI_TRIGGER to set it off. The thread will be waiting
* on the transfer completing as normal.
*/
priv->defertrig = ((features & HWFEAT_TRIGGER) != 0);
features &= ~HWFEAT_TRIGGER;
#endif
/* Other H/W features are not supported */
return (features == 0) ? OK : -ENOSYS;
}
#endif
/****************************************************************************
* Name: spi_send
*
* Description:
* Exchange one word on SPI
*
* Input Parameters:
* dev - Device-specific state data
* wd - The word to send. the size of the data is determined by the
* number of bits selected for the SPI interface.
*
* Returned Value:
* response
*
****************************************************************************/
static uint32_t spi_send(struct spi_dev_s *dev, uint32_t wd)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
uint32_t regval;
uint32_t ret;
DEBUGASSERT(priv && priv->spibase);
/* According to the number of bits, access data register as word or byte
* This is absolutely required because of packing. With <=8 bit frames,
* two bytes are received by a 16-bit read of the data register!
*/
if (spi_16bitmode(priv))
{
spi_writeword(priv, (uint16_t)(wd & 0xffff));
ret = (uint32_t)spi_readword(priv);
}
else
{
spi_writebyte(priv, (uint8_t)(wd & 0xff));
ret = (uint32_t)spi_readbyte(priv);
}
/* Check and clear any error flags (Reading from the SR clears the error
* flags).
*/
regval = spi_getreg(priv, STM32L4_SPI_SR_OFFSET);
if (spi_16bitmode(priv))
{
spiinfo("Sent: %04" PRIx32 " Return: %04" PRIx32
" Status: %02" PRIx32 "\n", wd, ret, regval);
}
else
{
spiinfo("Sent: %02" PRIx32 " Return: %02" PRIx32
" Status: %02" PRIx32 "\n", wd, ret, regval);
}
UNUSED(regval);
return ret;
}
/****************************************************************************
* Name: spi_exchange (no DMA). aka spi_exchange_nodma
*
* Description:
* Exchange a block of data on SPI without using DMA
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* rxbuffer - A pointer to a buffer in which to receive data
* nwords - the length of data to be exchanged in units of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into uint8_t's; if nbits >8, the data is packed into
* uint16_t's
*
* Returned Value:
* None
*
****************************************************************************/
#if !defined(CONFIG_STM32L4_SPI_DMA) || defined(CONFIG_STM32L4_DMACAPABLE)
#if !defined(CONFIG_STM32L4_SPI_DMA)
static void spi_exchange(struct spi_dev_s *dev, const void *txbuffer,
void *rxbuffer, size_t nwords)
#else
static void spi_exchange_nodma(struct spi_dev_s *dev,
const void *txbuffer, void *rxbuffer,
size_t nwords)
#endif
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
DEBUGASSERT(priv && priv->spibase);
spiinfo("txbuffer=%p rxbuffer=%p nwords=%d\n", txbuffer, rxbuffer, nwords);
/* 8- or 16-bit mode? */
if (spi_16bitmode(priv))
{
/* 16-bit mode */
const uint16_t *src = (const uint16_t *)txbuffer;
uint16_t *dest = (uint16_t *)rxbuffer;
uint16_t word;
while (nwords-- > 0)
{
/* Get the next word to write. Is there a source buffer? */
if (src)
{
word = *src++;
}
else
{
word = 0xffff;
}
/* Exchange one word */
word = (uint16_t)spi_send(dev, (uint32_t)word);
/* Is there a buffer to receive the return value? */
if (dest)
{
*dest++ = word;
}
}
}
else
{
/* 8-bit mode */
const uint8_t *src = (const uint8_t *)txbuffer;
uint8_t *dest = (uint8_t *)rxbuffer;
uint8_t word;
while (nwords-- > 0)
{
/* Get the next word to write. Is there a source buffer? */
if (src)
{
word = *src++;
}
else
{
word = 0xff;
}
/* Exchange one word */
word = (uint8_t)spi_send(dev, (uint32_t)word);
/* Is there a buffer to receive the return value? */
if (dest)
{
*dest++ = word;
}
}
}
}
#endif /* !CONFIG_STM32L4_SPI_DMA || CONFIG_STM32L4_DMACAPABLE */
/****************************************************************************
* Name: spi_exchange (with DMA capability)
*
* Description:
* Exchange a block of data on SPI using DMA
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* rxbuffer - A pointer to a buffer in which to receive data
* nwords - the length of data to be exchanged in units of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into uint8_t's; if nbits >8, the data is packed into
* uint16_t's
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef CONFIG_STM32L4_SPI_DMA
static void spi_exchange(struct spi_dev_s *dev, const void *txbuffer,
void *rxbuffer, size_t nwords)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)dev;
int ret;
#ifdef CONFIG_STM32L4_DMACAPABLE
if ((txbuffer &&
!stm32l4_dmacapable((uint32_t)txbuffer, nwords, priv->txccr)) ||
(rxbuffer &&
!stm32l4_dmacapable((uint32_t)rxbuffer, nwords, priv->rxccr)))
{
/* Unsupported memory region, fall back to non-DMA method. */
spi_exchange_nodma(dev, txbuffer, rxbuffer, nwords);
}
else
#endif
{
static uint16_t rxdummy = 0xffff;
static const uint16_t txdummy = 0xffff;
spiinfo("txbuffer=%p rxbuffer=%p nwords=%d\n",
txbuffer, rxbuffer, nwords);
DEBUGASSERT(priv && priv->spibase);
/* Setup DMAs */
spi_dmarxsetup(priv, rxbuffer, &rxdummy, nwords);
spi_dmatxsetup(priv, txbuffer, &txdummy, nwords);
#ifdef CONFIG_SPI_TRIGGER
/* Is deferred triggering in effect? */
if (!priv->defertrig)
{
/* No.. Start the DMAs */
spi_dmarxstart(priv);
spi_dmatxstart(priv);
}
else
{
/* Yes.. indicated that we are ready to be started */
priv->trigarmed = true;
}
#else
/* Start the DMAs */
spi_dmarxstart(priv);
spi_dmatxstart(priv);
#endif
/* Then wait for each to complete */
ret = spi_dmarxwait(priv);
if (ret >= 0)
{
ret = spi_dmatxwait(priv);
UNUSED(ret);
}
#ifdef CONFIG_SPI_TRIGGER
priv->trigarmed = false;
#endif
}
}
#endif /* CONFIG_STM32L4_SPI_DMA */
/****************************************************************************
* Name: spi_trigger
*
* Description:
* Trigger a previously configured DMA transfer.
*
* Input Parameters:
* dev - Device-specific state data
*
* Returned Value:
* OK - Trigger was fired
* ENOTSUP - Trigger not fired due to lack of DMA support
* EIO - Trigger not fired because not previously primed
*
****************************************************************************/
#ifdef CONFIG_SPI_TRIGGER
static int spi_trigger(struct spi_dev_s *dev)
{
#ifdef CONFIG_STM32L4_SPI_DMA
struct stm32_spidev_s *priv = (struct stm32_spidev_s *)dev;
if (!priv->trigarmed)
{
return -EIO;
}
spi_dmarxstart(priv);
spi_dmatxstart(priv);
return OK;
#else
return -ENOSYS;
#endif
}
#endif
/****************************************************************************
* Name: spi_sndblock
*
* Description:
* Send a block of data on SPI
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* nwords - the length of data to send from the buffer in number of
* words. The wordsize is determined by the number of
* bits-per-word selected for the SPI interface. If nbits <= 8,
* the data is packed into uint8_t's; if nbits >8, the data is
* packed into uint16_t's
*
* Returned Value:
* None
*
****************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_sndblock(struct spi_dev_s *dev,
const void *txbuffer,
size_t nwords)
{
spiinfo("txbuffer=%p nwords=%d\n", txbuffer, nwords);
return spi_exchange(dev, txbuffer, NULL, nwords);
}
#endif
/****************************************************************************
* Name: spi_recvblock
*
* Description:
* Receive a block of data from SPI
*
* Input Parameters:
* dev - Device-specific state data
* rxbuffer - A pointer to the buffer in which to receive data
* nwords - the length of data that can be received in the buffer in
* number of words. The wordsize is determined by the number of
* bits-per-word selected for the SPI interface. If nbits <= 8,
* the data is packed into uint8_t's; if nbits >8, the data is
* packed into uint16_t's
*
* Returned Value:
* None
*
****************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_recvblock(struct spi_dev_s *dev,
void *rxbuffer,
size_t nwords)
{
spiinfo("rxbuffer=%p nwords=%d\n", rxbuffer, nwords);
return spi_exchange(dev, NULL, rxbuffer, nwords);
}
#endif
/****************************************************************************
* Name: spi_pm_prepare
*
* Description:
* Request the driver to prepare for a new power state. This is a
* warning that the system is about to enter into a new power state. The
* driver should begin whatever operations that may be required to enter
* power state. The driver may abort the state change mode by returning
* a non-zero value from the callback function.
*
* Input Parameters:
* cb - Returned to the driver. The driver version of the callback
* structure may include additional, driver-specific state
* data at the end of the structure.
* domain - Identifies the activity domain of the state change
* pmstate - Identifies the new PM state
*
* Returned Value:
* 0 (OK) means the event was successfully processed and that the driver
* is prepared for the PM state change. Non-zero means that the driver
* is not prepared to perform the tasks needed achieve this power setting
* and will cause the state change to be aborted. NOTE: The prepare
* method will also be recalled when reverting from lower back to higher
* power consumption modes (say because another driver refused a lower
* power state change). Drivers are not permitted to return non-zero
* values when reverting back to higher power consumption modes!
*
****************************************************************************/
#ifdef CONFIG_PM
static int spi_pm_prepare(struct pm_callback_s *cb, int domain,
enum pm_state_e pmstate)
{
struct stm32l4_spidev_s *priv = (struct stm32l4_spidev_s *)((char *)cb -
offsetof(struct stm32l4_spidev_s, pm_cb));
/* Logic to prepare for a reduced power state goes here. */
switch (pmstate)
{
case PM_NORMAL:
case PM_IDLE:
break;
case PM_STANDBY:
case PM_SLEEP:
/* Check if exclusive lock for SPI bus is held. */
if (nxmutex_is_locked(&priv->lock))
{
/* Exclusive lock is held, do not allow entry to deeper PM
* states.
*/
return -EBUSY;
}
break;
default:
/* Should not get here */
break;
}
return OK;
}
#endif
/****************************************************************************
* Name: spi_bus_initialize
*
* Description:
* Initialize the selected SPI bus in its default state (Master, 8-bit,
* mode 0, etc.)
*
* Input Parameters:
* priv - private SPI device structure
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_bus_initialize(struct stm32l4_spidev_s *priv)
{
uint16_t setbits;
uint16_t clrbits;
#ifdef CONFIG_PM
int ret;
#endif
/* Configure CR1 and CR2. Default configuration:
* Mode 0: CR1.CPHA=0 and CR1.CPOL=0
* Master: CR1.MSTR=1
* 8-bit: CR2.DS=7
* MSB transmitted first: CR1.LSBFIRST=0
* Replace NSS with SSI & SSI=1: CR1.SSI=1 CR1.SSM=1 (prevents MODF
* error)
* Two lines full duplex: CR1.BIDIMODE=0 CR1.BIDIOIE=(Don't care)
* and CR1.RXONLY=0
*/
clrbits = SPI_CR1_CPHA | SPI_CR1_CPOL | SPI_CR1_BR_MASK |
SPI_CR1_LSBFIRST | SPI_CR1_RXONLY | SPI_CR1_BIDIOE |
SPI_CR1_BIDIMODE;
setbits = SPI_CR1_MSTR | SPI_CR1_SSI | SPI_CR1_SSM;
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, setbits, clrbits);
clrbits = SPI_CR2_DS_MASK;
setbits = SPI_CR2_DS_8BIT | SPI_CR2_FRXTH; /* FRXTH must be high in 8-bit mode */
spi_modifycr(STM32L4_SPI_CR2_OFFSET, priv, setbits, clrbits);
priv->frequency = 0;
priv->nbits = 8;
priv->mode = SPIDEV_MODE0;
/* Select a default frequency of approx. 400KHz */
spi_setfrequency((struct spi_dev_s *)priv, 400000);
/* CRCPOLY configuration */
spi_putreg(priv, STM32L4_SPI_CRCPR_OFFSET, 7);
#ifdef CONFIG_STM32L4_SPI_DMA
/* Get DMA channels. NOTE: stm32l4_dmachannel() will always assign the DMA
* channel. If the channel is not available, then stm32l4_dmachannel()
* will block and wait until the channel becomes available. WARNING: If
* you have another device sharing a DMA channel with SPI and the code
* never releases that channel, then the call to stm32l4_dmachannel() will
* hang forever in this function! Don't let your design do that!
*/
priv->rxdma = stm32l4_dmachannel(priv->rxch);
priv->txdma = stm32l4_dmachannel(priv->txch);
DEBUGASSERT(priv->rxdma && priv->txdma);
spi_modifycr(STM32L4_SPI_CR2_OFFSET, priv,
SPI_CR2_RXDMAEN | SPI_CR2_TXDMAEN, 0);
#endif
/* Enable spi */
spi_modifycr(STM32L4_SPI_CR1_OFFSET, priv, SPI_CR1_SPE, 0);
#ifdef CONFIG_PM
/* Register to receive power management callbacks */
ret = pm_register(&priv->pm_cb);
DEBUGASSERT(ret == OK);
UNUSED(ret);
#endif
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: stm32l4_spibus_initialize
*
* Description:
* Initialize the selected SPI bus
*
* Input Parameters:
* Port number (for hardware that has multiple SPI interfaces)
*
* Returned Value:
* Valid SPI device structure reference on success; a NULL on failure
*
****************************************************************************/
struct spi_dev_s *stm32l4_spibus_initialize(int bus)
{
struct stm32l4_spidev_s *priv = NULL;
irqstate_t flags = enter_critical_section();
#ifdef CONFIG_STM32L4_SPI1
if (bus == 1)
{
/* Select SPI1 */
priv = &g_spi1dev;
/* Only configure if the bus is not already configured */
if (!priv->initialized)
{
/* Configure SPI1 pins: SCK, MISO, and MOSI */
stm32l4_configgpio(GPIO_SPI1_SCK);
stm32l4_configgpio(GPIO_SPI1_MISO);
stm32l4_configgpio(GPIO_SPI1_MOSI);
/* Set up default configuration: Master, 8-bit, etc. */
spi_bus_initialize(priv);
priv->initialized = true;
}
}
else
#endif
#ifdef CONFIG_STM32L4_SPI2
if (bus == 2)
{
/* Select SPI2 */
priv = &g_spi2dev;
/* Only configure if the bus is not already configured */
if (!priv->initialized)
{
/* Configure SPI2 pins: SCK, MISO, and MOSI */
stm32l4_configgpio(GPIO_SPI2_SCK);
stm32l4_configgpio(GPIO_SPI2_MISO);
stm32l4_configgpio(GPIO_SPI2_MOSI);
/* Set up default configuration: Master, 8-bit, etc. */
spi_bus_initialize(priv);
priv->initialized = true;
}
}
else
#endif
#ifdef CONFIG_STM32L4_SPI3
if (bus == 3)
{
/* Select SPI3 */
priv = &g_spi3dev;
/* Only configure if the bus is not already configured */
if (!priv->initialized)
{
/* Configure SPI3 pins: SCK, MISO, and MOSI */
stm32l4_configgpio(GPIO_SPI3_SCK);
stm32l4_configgpio(GPIO_SPI3_MISO);
stm32l4_configgpio(GPIO_SPI3_MOSI);
/* Set up default configuration: Master, 8-bit, etc. */
spi_bus_initialize(priv);
priv->initialized = true;
}
}
else
#endif
{
spierr("ERROR: Unsupported SPI bus: %d\n", bus);
}
leave_critical_section(flags);
return (struct spi_dev_s *)priv;
}
#endif /* CONFIG_STM32L4_SPI1 || CONFIG_STM32L4_SPI2 || CONFIG_STM32L4_SPI3 */