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nuttx/arch/arm/src/stm32/stm32_spi.c
patacongo b3800e7dea Fix warning 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2140 42af7a65-404d-4744-a932-0658087f49c3
2009-10-15 23:22:53 +00:00

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/************************************************************************************
* arm/arm/src/stm32/stm32_spi.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
/************************************************************************************
* The external functions, stm32_spi1/2/3select and stm32_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.h). All other methods (including up_spiinitialize())
* are provided by common STM32 logic. To use this common SPI logic on your
* board:
*
* 1. Provide logic in stm32_boardinitialize() to configure SPI chip select
* pins.
* 2. Provide stm32_spi1/2/3select() and stm32_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.
* The select() methods must call stm32_spitake() when the chip is selected
* and stm32_spigive() when the chip is deselected. This assures mutually
* exclusive access to the SPI for the duration while a chip is selected.
* 3. Add a calls to up_spiinitialize() in your low level application
* initialization logic
* 4. The handle returned by up_spiinitialize() 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).
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <semaphore.h>
#include <errno.h>
#include <debug.h>
#include <arch/board/board.h>
#include <nuttx/arch.h>
#include <nuttx/spi.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip.h"
#include "stm32_internal.h"
#include "stm32_gpio.h"
#include "stm32_spi.h"
#if defined(CONFIG_STM32_SPI1) || defined(CONFIG_STM32_SPI2) || defined(CONFIG_STM32_SPI3)
/************************************************************************************
* Definitions
************************************************************************************/
/* Configuration ********************************************************************/
#ifdef CONFIG_STM32_SPI_INTERRUPTS
# error "Interrupt driven SPI not yet supported"
#endif
/************************************************************************************
* Private Types
************************************************************************************/
struct stm32_spidev_s
{
struct spi_dev_s spidev; /* Externally visible part of the SPI interface */
uint32 spibase; /* SPIn base address */
uint32 spiclock; /* Clocking for the SPI module */
#ifdef CONFIG_STM32_SPI_INTERRUPTS
uint8 spiirq; /* SPI IRQ number */
#endif
sem_t spisem;
};
/************************************************************************************
* Private Function Prototypes
************************************************************************************/
/* Helpers */
static inline uint16 spi_getreg(FAR struct stm32_spidev_s *priv, ubyte offset);
static inline void spi_putreg(FAR struct stm32_spidev_s *priv, ubyte offset,
uint16 value);
static inline uint16 spi_readword(FAR struct stm32_spidev_s *priv);
static inline void spi_writeword(FAR struct stm32_spidev_s *priv, uint16 byte);
/* SPI methods */
static uint32 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency);
static void spi_setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode);
static void spi_setbits(FAR struct spi_dev_s *dev, int nbits);
static uint16 spi_send(FAR struct spi_dev_s *dev, uint16 wd);
static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
FAR void *rxbuffer, size_t nwords);
#ifndef CONFIG_SPI_EXCHANGE
static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer,
size_t nwords);
static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer,
size_t nwords);
#endif
/* Initialization */
static void spi_portinitialize(FAR struct stm32_spidev_s *priv);
/************************************************************************************
* Private Data
************************************************************************************/
#ifdef CONFIG_STM32_SPI1
static const struct spi_ops_s g_sp1iops =
{
.select = stm32_spi1select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
.status = stm32_spi1status,
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
.registercallback = 0,
};
static struct stm32_spidev_s g_spi1dev =
{
.spidev = { &g_sp1iops },
.spibase = STM32_SPI1_BASE,
.spiclock = STM32_PCLK2_FREQUENCY,
#ifdef CONFIG_STM32_SPI_INTERRUPTS
.spiirq = STM32_IRQ_SPI1,
#endif
};
#endif
#ifdef CONFIG_STM32_SPI2
static const struct spi_ops_s g_sp2iops =
{
.select = stm32_spi2select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
.status = stm32_spi2status,
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
.registercallback = 0,
};
static struct stm32_spidev_s g_spi2dev =
{
.spidev = { &g_sp2iops },
.spibase = STM32_SPI2_BASE,
.spiclock = STM32_PCLK1_FREQUENCY,
#ifdef CONFIG_STM32_SPI_INTERRUPTS
.spiirq = STM32_IRQ_SPI2,
#endif
};
#endif
#ifdef CONFIG_STM32_SPI3
static const struct spi_ops_s g_sp3iops =
{
.select = stm32_spi3select,
.setfrequency = spi_setfrequency,
.setmode = spi_setmode,
.setbits = spi_setbits,
.status = stm32_spi3status,
.send = spi_send,
#ifdef CONFIG_SPI_EXCHANGE
.exchange = spi_exchange,
#else
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
#endif
.registercallback = 0,
};
static struct stm32_spidev_s g_spi3dev =
{
.spidev = { &g_sp3iops },
.spibase = STM32_SPI2_BASE,
.spiclock = STM32_PCLK1_FREQUENCY,
#ifdef CONFIG_STM32_SPI_INTERRUPTS
.spiirq = STM32_IRQ_SPI3,
#endif
};
#endif
/************************************************************************************
* Public Data
************************************************************************************/
/************************************************************************************
* 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 spi_getreg(FAR struct stm32_spidev_s *priv, ubyte 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(FAR struct stm32_spidev_s *priv, ubyte offset, uint16 value)
{
putreg16(value, priv->spibase + offset);
}
/************************************************************************************
* Name: spi_readword
*
* Description:
* Read one byte from SPI
*
* Input Parameters:
* priv - Device-specific state data
*
* Returned Value:
* Byte as read
*
************************************************************************************/
static inline uint16 spi_readword(FAR struct stm32_spidev_s *priv)
{
/* Wait until the receive buffer is not empty */
while ((spi_getreg(priv, STM32_SPI_SR_OFFSET) & SPI_SR_RXNE) != 0);
/* Then return the received byte */
return spi_getreg(priv, STM32_SPI_DR_OFFSET);
}
/************************************************************************************
* Name: spi_writeword
*
* Description:
* Write one byte to SPI
*
* Input Parameters:
* priv - Device-specific state data
* byte - Byte to send
*
* Returned Value:
* None
*
************************************************************************************/
static inline void spi_writeword(FAR struct stm32_spidev_s *priv, uint16 word)
{
/* Wait until the transmit buffer is empty */
while ((spi_getreg(priv, STM32_SPI_SR_OFFSET) & SPI_SR_TXE) != 0);
/* Then send the byte */
spi_putreg(priv, STM32_SPI_DR_OFFSET, word);
}
/************************************************************************************
* Name: spi_modifycr1
*
* Description:
* Clear and set bits in the CR1 register
*
* Input Parameters:
* priv - Device-specific state data
* clrbits - The bits to clear
* setbits - The bits to set
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_modifycr1(FAR struct stm32_spidev_s *priv, uint16 setbits, uint16 clrbits)
{
uint16 cr1;
cr1 = spi_getreg(priv, STM32_SPI_CR1_OFFSET);
cr1 &= ~clrbits;
cr1 |= setbits;
spi_putreg(priv, STM32_SPI_CR1_OFFSET, cr1);
}
/************************************************************************************
* 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 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
uint16 setbits;
uint32 actual;
/* 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_modifycr1(priv, setbits, SPI_CR1_BR_MASK);
return 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(FAR struct spi_dev_s *dev, enum spi_mode_e mode)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
uint16 setbits;
uint16 clrbits;
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_modifycr1(priv, setbits, clrbits);
}
/************************************************************************************
* Name: spi_setbits
*
* Description:
* Set the number of bits per word.
*
* Input Parameters:
* dev - Device-specific state data
* nbits - The number of bits requested
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_setbits(FAR struct spi_dev_s *dev, int nbits)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
uint16 setbits;
uint16 clrbits;
switch (nbits)
{
case 8:
setbits = 0;
clrbits = SPI_CR1_DFF;
break;
case 16:
setbits = SPI_CR1_DFF;
clrbits = 0;
break;
default:
return;
}
spi_modifycr1(priv, setbits, clrbits);
}
/************************************************************************************
* 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 uint16 spi_send(FAR struct spi_dev_s *dev, uint16 wd)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
DEBUGASSERT(priv && priv->spibase);
spi_writeword(priv, wd);
return spi_readword(priv);
}
/*************************************************************************
* Name: spi_exchange
*
* Description:
* Exchange a block of data on SPI
*
* Input Parameters:
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* txbuffer - A pointer to a buffer in which to receive data
* nwords - the length of data to be exchaned 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 ubytes; if nbits >8, the data is packed into uint16's
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
FAR void *rxbuffer, size_t nwords)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
DEBUGASSERT(priv && priv->spibase);
# warning "TODO: Need to incorporate DMA to get good SPI performance"
/* 8- or 16-bit mode? */
if ((spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_DFF) != 0)
{
/* 16-bit mode */
const uint16 *src = (const uint16*)txbuffer;;
uint16 *dest = (uint16*)rxbuffer;
uint16 word;
/* Get the next word to write. Is there a source buffer? */
if (src)
{
word = *src++;
}
else
{
word = 0xffff;
}
/* Exchange one word */
word = spi_send(dev, word);
/* Is there a buffer to receive the return value? */
if (dest)
{
*dest++ = word;
}
}
else
{
/* 8-bit mode */
const uint8 *src = (const uint8*)txbuffer;;
uint8 *dest = (uint8*)rxbuffer;
uint8 word;
/* Get the next word to write. Is there a source buffer? */
if (src)
{
word = *src++;
}
else
{
word = 0xff;
}
/* Exchange one word */
word = (uint8)spi_send(dev, (uint16)word);
/* Is there a buffer to receive the return value? */
if (dest)
{
*dest++ = word;
}
}
}
/*************************************************************************
* Name: spi_sndblock
*
* Description:
* Send a block of data on SPI
*
* Input Parameters:
* dev - Device-specific state data
* buffer - 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 ubytes; if nbits >8, the data is packed into uint16's
*
* Returned Value:
* None
*
************************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer, size_t nwords)
{
return spi_exchange(dev, buffer, NULL, nwords);
}
#endif
/************************************************************************************
* Name: spi_recvblock
*
* Description:
* Revice a block of data from SPI
*
* Input Parameters:
* dev - Device-specific state data
* buffer - A pointer to the buffer in which to recieve 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 ubytes; if nbits >8, the data is packed into uint16's
*
* Returned Value:
* None
*
************************************************************************************/
#ifndef CONFIG_SPI_EXCHANGE
static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer, size_t nwords)
{
return spi_exchange(dev, NULL, buffer, nwords);
}
#endif
/************************************************************************************
* Name: spi_portinitialize
*
* Description:
* Initialize the selected SPI port in its default state (Master, 8-bit, mode 0, etc.)
*
* Input Parameter:
* priv - private SPI device structure
*
* Returned Value:
* None
*
************************************************************************************/
static void spi_portinitialize(FAR struct stm32_spidev_s *priv)
{
uint16 setbits;
uint16 clrbits;
/* Configure CR1. Default configuration:
* Mode 0: CPHA=0 and CPOL=0
* Master: MSTR=1
* 8-bit: DFF=0
* MSB tranmitted first: LSBFIRST=0
* No software slave management: SSI=0 SSM=0
* Two lines full duplex: BIDIMODE=0 BIDIOIE=(Don't care) and RXONLY=0
*/
clrbits = SPI_CR1_CPHA|SPI_CR1_CPOL|SPI_CR1_BR_MASK|SPI_CR1_LSBFIRST|SPI_CR1_SSI|
SPI_CR1_SSM|SPI_CR1_RXONLY|SPI_CR1_DFF|SPI_CR1_BIDIOE|SPI_CR1_BIDIMODE;
setbits = SPI_CR1_MSTR;
spi_modifycr1(priv, setbits, clrbits);
/* Select a default frequency of approx. 400KHz */
spi_setfrequency((FAR struct spi_dev_s *)priv, 400000);
/* CRCPOLY configuration */
spi_putreg(priv, STM32_SPI_CRCPR_OFFSET, 7);
/* Enable the SPI semaphore that enforces mutually exclusive access */
sem_init(&priv->spisem, 0, 1);
/* Enable spi */
spi_modifycr1(priv, SPI_CR1_SPE, 0);
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: up_spiinitialize
*
* Description:
* Initialize the selected SPI port
*
* Input Parameter:
* Port number (for hardware that has mutiple SPI interfaces)
*
* Returned Value:
* Valid SPI device structure reference on succcess; a NULL on failure
*
************************************************************************************/
FAR struct spi_dev_s *up_spiinitialize(int port)
{
FAR struct stm32_spidev_s *priv = NULL;
irqstate_t flags;
flags = irqsave();
#ifdef CONFIG_STM32_SPI1
if (port == 0)
{
uint32 mapr;
/* Select SPI1 */
priv = &g_spi1dev;
/* Handle pin mapping */
mapr = getreg32(STM32_AFIO_MAPR);
#ifdef CONFIG_STM32_SPI1_REMAP
mapr |= AFIO_MAPR_SPI1_REMAP;
#else
mapr &= ~AFIO_MAPR_SPI1_REMAP;
#endif
putreg32(mapr, STM32_AFIO_MAPR);
/* Configure SPI1 pins: SCK, MISO, and MOSI */
stm32_configgpio(GPIO_SPI1_SCK);
stm32_configgpio(GPIO_SPI1_MISO);
stm32_configgpio(GPIO_SPI1_MOSI);
/* Set up default configuration: Master, 8-bit, etc. */
spi_portinitialize(priv);
}
else
#endif
#ifdef CONFIG_STM32_SPI2
if (port == 1)
{
/* Select SPI2 */
priv = &g_spi2dev;
/* Set up default configuration: Master, 8-bit, etc. */
spi_portinitialize(priv);
}
else
#endif
#ifdef CONFIG_STM32_SPI3
if (port == 3)
{
/* Select SPI3 */
priv = &g_spi3dev;
/* Handle pin mapping */
#ifdef CONFIG_STM32_SPI3_REMAP
# error "Available only in connectivity devices"
#endif
/* Configure SPI3 pins: SCK, MISO, and MOSI */
stm32_configgpio(GPIO_SPI3_SCK);
stm32_configgpio(GPIO_SPI3_MISO);
stm32_configgpio(GPIO_SPI3_MOSI);
/* Set up default configuration: Master, 8-bit, etc. */
spi_portinitialize(priv);
}
#endif
irqrestore(flags);
return (FAR struct spi_dev_s *)priv;
}
/************************************************************************************
* Name: stm32_spitake() and stm32_spigive()
*
* Description:
* The stm32_spi1/2/3select() and stm32_spi1/2/3status() methods must call
* stm32_spitake() when the chip is selected and stm32_spigive() when the chip is
* deselected. This assures mutually exclusive access to the SPI for the duration
* while a chip is selected.
*
************************************************************************************/
void stm32_spitake(FAR struct spi_dev_s *dev)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&priv->spisem) != 0)
{
/* The only case that an error should occur here is if the wait was awakened
* by a signal.
*/
ASSERT(*get_errno_ptr() == EINTR);
}
}
void stm32_spigive(FAR struct spi_dev_s *dev)
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
(void)sem_post(&priv->spisem);
}
#endif /* CONFIG_STM32_SPI1 || CONFIG_STM32_SPI2 || CONFIG_STM32_SPI3 */
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