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drivers/spi/spi_bitbang.c: Fix typos and nxstyle complaints.

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Ouss4 2020-06-13 19:05:01 +01:00 committed by patacongo
parent bd82486f1c
commit 530cad304f
4 changed files with 48 additions and 36 deletions
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5
boards/arm/sam34/arduino-due/src/sam_mmcsd.c
View File

@ -93,7 +93,7 @@
/* Calibration value for timing loop */ /* Calibration value for timing loop */
#define SPI_BITBAND_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC #define SPI_BITBANG_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC
/* SPI_PERBIT_NSEC is the minimum time to transfer one bit. This determines /* SPI_PERBIT_NSEC is the minimum time to transfer one bit. This determines
* the maximum frequency and is also used to calculate delays to achieve * the maximum frequency and is also used to calculate delays to achieve
@ -275,7 +275,8 @@ int sam_sdinitialize(int minor)
ret = mmcsd_spislotinitialize(minor, SAM34_MMCSDSLOTNO, spi); ret = mmcsd_spislotinitialize(minor, SAM34_MMCSDSLOTNO, spi);
if (ret < 0) if (ret < 0)
{ {
ferr("ERROR: Failed to bind bit bang SPI device to MMC/SD slot %d: %d\n", ferr("ERROR: Failed to bind bit bang SPI device"
" to MMC/SD slot %d: %d\n",
SAM34_MMCSDSLOTNO, ret); SAM34_MMCSDSLOTNO, ret);
return ret; return ret;
} }

2
boards/arm/sam34/arduino-due/src/sam_touchscreen.c
View File

@ -108,7 +108,7 @@
/* Calibration value for timing loop */ /* Calibration value for timing loop */
#define SPI_BITBAND_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC #define SPI_BITBANG_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC
/* SPI_PERBIT_NSEC is the minimum time to transfer one bit. This determines /* SPI_PERBIT_NSEC is the minimum time to transfer one bit. This determines
* the maximum frequency and is also used to calculate delays to achieve * the maximum frequency and is also used to calculate delays to achieve

14
drivers/spi/spi_bitbang.c
View File

@ -55,8 +55,8 @@
* Pre-processor Definitions * Pre-processor Definitions
****************************************************************************/ ****************************************************************************/
/* This file holds the static, device-independ portion of the generica SPI- /* This file holds the static, device-independent portion of the generic
* bit-bang driver. The full driver consists of 5 files: * SPI-bit-bang driver. The full driver consists of 5 files:
* *
* 1. drivers/spi/spi_bitbang.c: This file. This file holds the basic * 1. drivers/spi/spi_bitbang.c: This file. This file holds the basic
* SPI driver framework and not perform any direct bit-bang operations. * SPI driver framework and not perform any direct bit-bang operations.
@ -68,17 +68,17 @@
* 3. boards/<arch>/<chip>/<board>/src/<file>: The implementation of the * 3. boards/<arch>/<chip>/<board>/src/<file>: The implementation of the
* low-level bit-bang logic resides in some file in the board source * low-level bit-bang logic resides in some file in the board source
* directory. This board-specific logic includes the bit-bang skeleton * directory. This board-specific logic includes the bit-bang skeleton
* logic provided in include/nuttx/spi/spi_bitband.c. * logic provided in include/nuttx/spi/spi_bitbang.c.
* 4. include/nuttx/spi/spi_bitband.c. Despite the .c extension, this * 4. include/nuttx/spi/spi_bitbang.c. Despite the .c extension, this is
* really an included file. It is used in this way: 1) The board- * really an included file. It is used in this way: 1) The board-
* specific logic in boards/<arch>/<chip>/<board>/src/<file> provides * specific logic in boards/<arch>/<chip>/<board>/src/<file> provides
* some definitions then 2) includes include/nuttx/spi/spi_bitband.c. * some definitions then 2) includes include/nuttx/spi/spi_bitbang.c.
* That file will then use those definitions to implement the low-level * That file will then use those definitions to implement the low-level
* bit-bang logic. the board-specific logic then calls * bit-bang logic. The board-specific logic then calls
* spi_create_bitbang() in this file to instantiate the complete SPI * spi_create_bitbang() in this file to instantiate the complete SPI
* driver. * driver.
* *
* See include/nuttx/spi/spi_bitband.c for more detailed usage * See include/nuttx/spi/spi_bitbang.c for more detailed usage
* information. * information.
*/ */

63
include/nuttx/spi/spi_bitbang.c
View File

@ -44,7 +44,9 @@
/**************************************************************************** /****************************************************************************
* Pre-processor Definitions * Pre-processor Definitions
****************************************************************************/ ****************************************************************************/
/* Usage ********************************************************************/ /* Usage ********************************************************************/
/* To use this logic, you should provide a C file that does the following: /* To use this logic, you should provide a C file that does the following:
* *
* - Defines SPI_SETSCK and SPI_CLRSCK to set and clear the SCK signal * - Defines SPI_SETSCK and SPI_CLRSCK to set and clear the SCK signal
@ -53,12 +55,12 @@
* - Defines SPI_PERBIT_NSEC which is the minimum time to transfer one bit. * - Defines SPI_PERBIT_NSEC which is the minimum time to transfer one bit.
* This determines the maximum frequency. * This determines the maximum frequency.
* - Other configuration options: * - Other configuration options:
* SPI_BITBAND_LOOPSPERMSEC - Delay loop calibration * SPI_BITBANG_LOOPSPERMSEC - Delay loop calibration
* SPI_BITBANG_DISABLEMODE0 - Define to disable Mode 0 support * SPI_BITBANG_DISABLEMODE0 - Define to disable Mode 0 support
* SPI_BITBANG_DISABLEMODE1 - Define to disable Mode 1 support * SPI_BITBANG_DISABLEMODE1 - Define to disable Mode 1 support
* SPI_BITBANG_DISABLEMODE2 - Define to disable Mode 2 support * SPI_BITBANG_DISABLEMODE2 - Define to disable Mode 2 support
* SPI_BITBANG_DISABLEMODE3 - Define to disable Mode 3 support * SPI_BITBANG_DISABLEMODE3 - Define to disable Mode 3 support
* - Provide implementations of spi_select(), spi_status(), and spi_cmddata(). * - Provide implementations of spi_select(), spi_status() and spi_cmddata().
* - Then include this file * - Then include this file
* - Provide an initialization function that initializes the GPIO pins used * - Provide an initialization function that initializes the GPIO pins used
* in the bit bang interface and calls spi_create_bitbang(). * in the bit bang interface and calls spi_create_bitbang().
@ -115,6 +117,7 @@ static const struct spi_bitbang_ops_s g_spiops =
/**************************************************************************** /****************************************************************************
* Private Functions * Private Functions
****************************************************************************/ ****************************************************************************/
/**************************************************************************** /****************************************************************************
* Name: spi_delay * Name: spi_delay
* *
@ -122,10 +125,10 @@ static const struct spi_bitbang_ops_s g_spiops =
* Delay for a specified number of loops * Delay for a specified number of loops
* *
* Input Parameters: * Input Parameters:
* count - The number of loops * holdtime - The number of loops
* *
* Returned Value: * Returned Value:
* Returns the actual frequency selected * None.
* *
****************************************************************************/ ****************************************************************************/
@ -143,7 +146,7 @@ static void spi_delay(uint32_t holdtime)
* Set the SPI frequency. * Set the SPI frequency.
* *
* Input Parameters: * Input Parameters:
* dev - Device-specific state data * priv - Device-specific state data
* frequency - The SPI frequency requested * frequency - The SPI frequency requested
* *
* Returned Value: * Returned Value:
@ -151,7 +154,8 @@ static void spi_delay(uint32_t holdtime)
* *
****************************************************************************/ ****************************************************************************/
static uint32_t spi_setfrequency(FAR struct spi_bitbang_s *priv, uint32_t frequency) static uint32_t spi_setfrequency(FAR struct spi_bitbang_s *priv,
uint32_t frequency)
{ {
uint32_t pnsec; uint32_t pnsec;
@ -160,11 +164,14 @@ static uint32_t spi_setfrequency(FAR struct spi_bitbang_s *priv, uint32_t freque
* wait, set low, wait, set high, wait, etc. * wait, set low, wait, set high, wait, etc.
* *
* Here we calcalute the half period of the frequency in nanoseconds (i.e., * Here we calcalute the half period of the frequency in nanoseconds (i.e.,
* the amount of time that the clock should remain in the high or low state). * the amount of time that the clock should remain in the high or low
* state).
* *
* frequency = psec / 1 sec psec = full period in seconds * frequency = psec / 1 sec
* psec = full period in seconds
* psec = 1 sec / frequency * psec = 1 sec / frequency
* pnsec = 1000000000 nsec / (2 * frequency) pnsec = full period in nsec * pnsec = 1000000000 nsec / (2 * frequency)
* pnsec = full period in nsec
* *
* As examples: * As examples:
* 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100 * 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100
@ -190,41 +197,43 @@ static uint32_t spi_setfrequency(FAR struct spi_bitbang_s *priv, uint32_t freque
pnsec = (pnsec + 1) >> 1; pnsec = (pnsec + 1) >> 1;
/* But what we really want is the hold time in loop counts. We know that /* But what we really want is the hold time in loop counts. We know that
* SPI_BITBAND_LOOPSPERMSEC is the number of times through a delay loop * SPI_BITBANG_LOOPSPERMSEC is the number of times through a delay loop
* to get 1 millisecond. * to get 1 millisecond.
* *
* SPI_BITBAND_LOOPSPERMSEC / 1000000 is then the number of counts * SPI_BITBANG_LOOPSPERMSEC / 1000000 is then the number of counts
* to get 1 nanosecond. In reality, this is a number less than zero. But * to get 1 nanosecond. In reality, this is a number less than zero. But
* then we can use this to calculate: * then we can use this to calculate:
* *
* holdtime loops/hold = pnsec nsec/hold * (SPI_BITBAND_LOOPSPERMSEC / 1000000) loops/nsec * holdtime loops/hold = pnsec nsec/hold * (SPI_BITBANG_LOOPSPERMSEC /
* 1000000) loops/nsec
* *
* As examples: * As examples:
* 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100; pnsec = 1200; * 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100; pnsec = 1200;
* SPI_BITBAND_LOOPSPERMSEC = 5000 * SPI_BITBANG_LOOPSPERMSEC = 5000
* holdtime = (1200 * 5000 + 500000) / 1000000 = 6 * holdtime = (1200 * 5000 + 500000) / 1000000 = 6
* 2) frequency = 20MHz; SPI_PERBIT_NSEC = 100; pnsec = 0; * 2) frequency = 20MHz; SPI_PERBIT_NSEC = 100; pnsec = 0;
* SPI_BITBAND_LOOPSPERMSEC = 5000 * SPI_BITBANG_LOOPSPERMSEC = 5000
* holdtime = (0 * 5000 + 500000) / 1000000 = 0 * holdtime = (0 * 5000 + 500000) / 1000000 = 0
*/ */
priv->holdtime = (pnsec * SPI_BITBAND_LOOPSPERMSEC + 500000) / 1000000; priv->holdtime = (pnsec * SPI_BITBANG_LOOPSPERMSEC + 500000) / 1000000;
/* Let's do our best to calculate the actual frequency /* Let's do our best to calculate the actual frequency
* *
* As examples: * As examples:
* 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100; * 1) frequency = 400KHz; SPI_PERBIT_NSEC = 100;
* SPI_BITBAND_LOOPSPERMSEC = 5000; holdtime = 6 * SPI_BITBANG_LOOPSPERMSEC = 5000; holdtime = 6
* pnsec = 2 * 1000000 * 6 / 5000 + 100 = 2500 nsec * pnsec = 2 * 1000000 * 6 / 5000 + 100 = 2500 nsec
* frequency = 400KHz * frequency = 400KHz
* 2) frequency = 20MHz; SPI_PERBIT_NSEC = 100; holdtime = 0 * 2) frequency = 20MHz; SPI_PERBIT_NSEC = 100; holdtime = 0
* SPI_BITBAND_LOOPSPERMSEC = 5000; holdtime = 0 * SPI_BITBANG_LOOPSPERMSEC = 5000; holdtime = 0
* pnsec = 2 * 0 * 6 / 5000 + 100 = 100 nsec * pnsec = 2 * 0 * 6 / 5000 + 100 = 100 nsec
* frequency = 10MHz * frequency = 10MHz
*/ */
pnsec = 2 * 1000000 * priv->holdtime / SPI_BITBAND_LOOPSPERMSEC + SPI_PERBIT_NSEC; pnsec = 2 * 1000000 * priv->holdtime / SPI_BITBANG_LOOPSPERMSEC +
SPI_PERBIT_NSEC;
frequency = 1000000000ul / pnsec; frequency = 1000000000ul / pnsec;
return frequency; return frequency;
} }
@ -236,8 +245,8 @@ static uint32_t spi_setfrequency(FAR struct spi_bitbang_s *priv, uint32_t freque
* Select the current SPI mode * Select the current SPI mode
* *
* Input Parameters: * Input Parameters:
* dev - Device-specific state data * priv - Device-specific state data
* mode - the new SPI mode * mode - The new SPI mode
* *
* Returned Value: * Returned Value:
* None * None
@ -466,8 +475,8 @@ static uint16_t spi_bitexchange2(uint16_t dataout, uint32_t holdtime)
{ {
uint16_t datain; uint16_t datain;
/* Here the clock is is in the resting set (high). Set MOSI output and wait /* Here the clock is is in the resting set (high). Set MOSI output and
* for the hold time * wait for the hold time
*/ */
if (dataout != 0) if (dataout != 0)
@ -568,7 +577,7 @@ static uint16_t spi_bitexchange3(uint16_t dataout, uint32_t holdtime)
* Name: spi_exchange * Name: spi_exchange
* *
* Description: * Description:
* Exahange on word of data on SPI * Exahange one word of data on SPI
* *
* Input Parameters: * Input Parameters:
* priv - Device-specific state data * priv - Device-specific state data
@ -580,7 +589,8 @@ static uint16_t spi_bitexchange3(uint16_t dataout, uint32_t holdtime)
****************************************************************************/ ****************************************************************************/
#ifdef CONFIG_SPI_BITBANG_VARWIDTH #ifdef CONFIG_SPI_BITBANG_VARWIDTH
static uint16_t spi_exchange(FAR struct spi_bitbang_s *priv, uint16_t dataout) static uint16_t spi_exchange(FAR struct spi_bitbang_s *priv,
uint16_t dataout)
{ {
bitexchange_t exchange = priv->exchange; bitexchange_t exchange = priv->exchange;
uint32_t holdtime = priv->holdtime; uint32_t holdtime = priv->holdtime;
@ -609,7 +619,8 @@ static uint16_t spi_exchange(FAR struct spi_bitbang_s *priv, uint16_t dataout)
} }
#else #else
static uint16_t spi_exchange(FAR struct spi_bitbang_s *priv, uint16_t dataout) static uint16_t spi_exchange(FAR struct spi_bitbang_s *priv,
uint16_t dataout)
{ {
bitexchange_t exchange = priv->exchange; bitexchange_t exchange = priv->exchange;
uint32_t holdtime = priv->holdtime; uint32_t holdtime = priv->holdtime;