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WiringPi
mirror of https://github.com/WiringPi/WiringPi.git
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Added a clock mode to enable the GPIo pins to be set with 

one of the GPCLK drivers to generate a frequency up to
19.2MHz.

Tidied some code up and added the clock functions into the gpio
utility.
pull/22/head
Gordon Henderson 11 years ago
parent
4ba36e247a
commit
56c77b5a2e
4 changed files with 247 additions and 133 deletions
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  1. +8
    -2
      gpio/gpio.1
  2. +38
    -9
      gpio/gpio.c
  3. +195
    -122
      wiringPi/wiringPi.c
  4. +6
    -0
      wiringPi/wiringPi.h

+ 8
- 2
gpio/gpio.1 View File

@@ -9,7 +9,7 @@ gpio \- Command-line access to Raspberry Pi and PiFace GPIO
.PP
.B gpio
.B [ \-g ]
.B read/write/wb/pwm/mode ...
.B read/write/wb/pwm/clock/mode ...
.PP
.B gpio
.B [ \-p ]
@@ -104,7 +104,13 @@ mode.

.TP
.B pwm <pin> <value>
Write a PWM value (0-1023) to the given pin.
Write a PWM value (0-1023) to the given pin. The pin needs to be put
into PWM mode first.

.TP
.B clock <pin> <frequency>
Set the output frequency on the given pin. The pin needs to be put into
clock mode first.

.TP
.B mode <pin> <mode>


+ 38
- 9
gpio/gpio.c View File

@@ -42,13 +42,13 @@ extern int wiringPiDebug ;
# define FALSE (1==2)
#endif

#define VERSION "1.10"
#define VERSION "1.11"

static int wpMode ;

char *usage = "Usage: gpio -v\n"
" gpio -h\n"
" gpio [-g] <read/write/wb/pwm/mode> ...\n"
" gpio [-g] <read/write/wb/pwm/clock/mode> ...\n"
" gpio [-p] <read/write/wb> ...\n"
" gpio readall\n"
" gpio unexportall/exports ...\n"
@@ -541,15 +541,16 @@ void doMode (int argc, char *argv [])

mode = argv [3] ;

/**/ if (strcasecmp (mode, "in") == 0) pinMode (pin, INPUT) ;
else if (strcasecmp (mode, "out") == 0) pinMode (pin, OUTPUT) ;
else if (strcasecmp (mode, "pwm") == 0) pinMode (pin, PWM_OUTPUT) ;
else if (strcasecmp (mode, "up") == 0) pullUpDnControl (pin, PUD_UP) ;
else if (strcasecmp (mode, "down") == 0) pullUpDnControl (pin, PUD_DOWN) ;
else if (strcasecmp (mode, "tri") == 0) pullUpDnControl (pin, PUD_OFF) ;
/**/ if (strcasecmp (mode, "in") == 0) pinMode (pin, INPUT) ;
else if (strcasecmp (mode, "out") == 0) pinMode (pin, OUTPUT) ;
else if (strcasecmp (mode, "pwm") == 0) pinMode (pin, PWM_OUTPUT) ;
else if (strcasecmp (mode, "clock") == 0) pinMode (pin, GPIO_CLOCK) ;
else if (strcasecmp (mode, "up") == 0) pullUpDnControl (pin, PUD_UP) ;
else if (strcasecmp (mode, "down") == 0) pullUpDnControl (pin, PUD_DOWN) ;
else if (strcasecmp (mode, "tri") == 0) pullUpDnControl (pin, PUD_OFF) ;
else
{
fprintf (stderr, "%s: Invalid mode: %s. Should be in/out/pwm/up/down/tri\n", argv [1], mode) ;
fprintf (stderr, "%s: Invalid mode: %s. Should be in/out/pwm/clock/up/down/tri\n", argv [1], mode) ;
exit (1) ;
}
}
@@ -755,6 +756,33 @@ void doRead (int argc, char *argv [])


/*
* doClock:
* Output a clock on a pin
*********************************************************************************
*/

void doClock (int argc, char *argv [])
{
int pin, freq ;

if (argc != 4)
{
fprintf (stderr, "Usage: %s clock <pin> <freq>\n", argv [0]) ;
exit (1) ;
}

pin = atoi (argv [2]) ;

if ((wpMode == WPI_MODE_PINS) && ((pin < 0) || (pin >= NUM_PINS)))
return ;

freq = atoi (argv [3]) ;

gpioClockSet (pin, freq) ;
}


/*
* doPwm:
* Output a PWM value on a pin
*********************************************************************************
@@ -980,6 +1008,7 @@ int main (int argc, char *argv [])
else if (strcasecmp (argv [1], "write") == 0) doWrite (argc, argv) ;
else if (strcasecmp (argv [1], "wb") == 0) doWriteByte (argc, argv) ;
else if (strcasecmp (argv [1], "pwm" ) == 0) doPwm (argc, argv) ;
else if (strcasecmp (argv [1], "clock") == 0) doClock (argc, argv) ;
else if (strcasecmp (argv [1], "mode" ) == 0) doMode (argc, argv) ;
else
{


+ 195
- 122
wiringPi/wiringPi.c View File

@@ -79,6 +79,7 @@ void (*pullUpDnControl) (int pin, int pud) ;
void (*digitalWrite) (int pin, int value) ;
void (*digitalWriteByte) (int value) ;
void (*pwmWrite) (int pin, int value) ;
void (*gpioClockSet) (int pin, int value) ;
void (*setPadDrive) (int group, int value) ;
int (*digitalRead) (int pin) ;
int (*waitForInterrupt) (int pin, int mS) ;
@@ -97,6 +98,24 @@ void (*pwmSetClock) (int divisor) ;
#define BCM_PASSWORD 0x5A000000


// The BCM2835 has 54 GPIO pins.
// BCM2835 data sheet, Page 90 onwards.
// There are 6 control registers, each control the functions of a block
// of 10 pins.
// Each control register has 10 sets of 3 bits per GPIO pin - the ALT values
//
// 000 = GPIO Pin X is an input
// 001 = GPIO Pin X is an output
// 100 = GPIO Pin X takes alternate function 0
// 101 = GPIO Pin X takes alternate function 1
// 110 = GPIO Pin X takes alternate function 2
// 111 = GPIO Pin X takes alternate function 3
// 011 = GPIO Pin X takes alternate function 4
// 010 = GPIO Pin X takes alternate function 5
//
// So the 3 bits for port X are:
// X / 10 + ((X % 10) * 3)

// Port function select bits

#define FSEL_INPT 0b000
@@ -110,20 +129,21 @@ void (*pwmSetClock) (int divisor) ;
#define FSEL_ALT5 0b010

// Access from ARM Running Linux
// Take from Gert/Doms code. Some of this is not in the manual
// Taken from Gert/Doms code. Some of this is not in the manual
// that I can find )-:

#define BCM2708_PERI_BASE 0x20000000
#define GPIO_PADS (BCM2708_PERI_BASE + 0x100000)
#define CLOCK_BASE (BCM2708_PERI_BASE + 0x101000)
#define GPIO_BASE (BCM2708_PERI_BASE + 0x200000)
#define GPIO_TIMER (BCM2708_PERI_BASE + 0x00B000)
#define GPIO_PWM (BCM2708_PERI_BASE + 0x20C000)
#define BCM2708_PERI_BASE 0x20000000
#define GPIO_PADS (BCM2708_PERI_BASE + 0x00100000)
#define CLOCK_BASE (BCM2708_PERI_BASE + 0x00101000)
#define GPIO_BASE (BCM2708_PERI_BASE + 0x00200000)
#define GPIO_TIMER (BCM2708_PERI_BASE + 0x0000B000)
#define GPIO_PWM (BCM2708_PERI_BASE + 0x0020C000)

#define PAGE_SIZE (4*1024)
#define BLOCK_SIZE (4*1024)

// PWM
// Word offsets into the PWM control region

#define PWM_CONTROL 0
#define PWM_STATUS 1
@@ -132,17 +152,11 @@ void (*pwmSetClock) (int divisor) ;
#define PWM1_RANGE 8
#define PWM1_DATA 9

// Clock regsiter offsets

#define PWMCLK_CNTL 40
#define PWMCLK_DIV 41

#define PWM1_MS_MODE 0x8000 // Run in MS mode
#define PWM1_USEFIFO 0x2000 // Data from FIFO
#define PWM1_REVPOLAR 0x1000 // Reverse polarity
#define PWM1_OFFSTATE 0x0800 // Ouput Off state
#define PWM1_REPEATFF 0x0400 // Repeat last value if FIFO empty
#define PWM1_SERIAL 0x0200 // Run in serial mode
#define PWM1_ENABLE 0x0100 // Channel Enable

#define PWM0_MS_MODE 0x0080 // Run in MS mode
#define PWM0_USEFIFO 0x0020 // Data from FIFO
#define PWM0_REVPOLAR 0x0010 // Reverse polarity
@@ -151,7 +165,16 @@ void (*pwmSetClock) (int divisor) ;
#define PWM0_SERIAL 0x0002 // Run in serial mode
#define PWM0_ENABLE 0x0001 // Channel Enable

#define PWM1_MS_MODE 0x8000 // Run in MS mode
#define PWM1_USEFIFO 0x2000 // Data from FIFO
#define PWM1_REVPOLAR 0x1000 // Reverse polarity
#define PWM1_OFFSTATE 0x0800 // Ouput Off state
#define PWM1_REPEATFF 0x0400 // Repeat last value if FIFO empty
#define PWM1_SERIAL 0x0200 // Run in serial mode
#define PWM1_ENABLE 0x0100 // Channel Enable

// Timer
// Word offsets

#define TIMER_LOAD (0x400 >> 2)
#define TIMER_VALUE (0x404 >> 2)
@@ -184,24 +207,6 @@ static int wiringPiMode = WPI_MODE_UNINITIALISED ;

int wiringPiDebug = FALSE ;

// The BCM2835 has 54 GPIO pins.
// BCM2835 data sheet, Page 90 onwards.
// There are 6 control registers, each control the functions of a block
// of 10 pins.
// Each control register has 10 sets of 3 bits per GPIO pin:
//
// 000 = GPIO Pin X is an input
// 001 = GPIO Pin X is an output
// 100 = GPIO Pin X takes alternate function 0
// 101 = GPIO Pin X takes alternate function 1
// 110 = GPIO Pin X takes alternate function 2
// 111 = GPIO Pin X takes alternate function 3
// 011 = GPIO Pin X takes alternate function 4
// 010 = GPIO Pin X takes alternate function 5
//
// So the 3 bits for port X are:
// X / 10 + ((X % 10) * 3)

// sysFds:
// Map a file descriptor from the /sys/class/gpio/gpioX/value

@@ -341,11 +346,14 @@ static uint8_t gpioToFEN [] =
#endif


// gpioToPUDCLK
// (Word) offset to the Pull Up Down Clock regsiter
// GPPUD:
// GPIO Pin pull up/down register

#define GPPUD 37

// gpioToPUDCLK
// (Word) offset to the Pull Up Down Clock regsiter

static uint8_t gpioToPUDCLK [] =
{
38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,
@@ -368,6 +376,9 @@ static uint8_t gpioToPwmALT [] =
0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
} ;

// gpioToPwmPort
// The port value to put a GPIO pin into PWM mode

static uint8_t gpioToPwmPort [] =
{
0, 0, 0, 0, 0, 0, 0, 0, // 0 -> 7
@@ -381,6 +392,55 @@ static uint8_t gpioToPwmPort [] =

} ;

// gpioToGpClkALT:
// ALT value to put a GPIO pin into GP Clock mode.
// On the Pi we can really only use BCM_GPIO_4 and BCM_GPIO_21
// for clocks 0 and 1 respectivey, however I'll include the full
// list for completeness - maybe one day...

#define GPIO_CLOCK_SOURCE 1

// gpioToGpClkALT0:

static uint8_t gpioToGpClkALT0 [] =
{
0, 0, 0, 0, FSEL_ALT0, FSEL_ALT0, FSEL_ALT0, 0, // 0 -> 7
0, 0, 0, 0, 0, 0, 0, 0, // 8 -> 15
0, 0, 0, 0, FSEL_ALT5, FSEL_ALT5, 0, 0, // 16 -> 23
0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
FSEL_ALT0, 0, FSEL_ALT0, 0, 0, 0, 0, 0, // 32 -> 39
0, 0, FSEL_ALT0, FSEL_ALT0, FSEL_ALT0, 0, 0, 0, // 40 -> 47
0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
} ;

// gpioToClk:
// (word) Offsets to the clock Control and Divisor register

static uint8_t gpioToClkCon [] =
{
-1, -1, -1, -1, 28, 30, 32, -1, // 0 -> 7
-1, -1, -1, -1, -1, -1, -1, -1, // 8 -> 15
-1, -1, -1, -1, 28, 30, -1, -1, // 16 -> 23
-1, -1, -1, -1, -1, -1, -1, -1, // 24 -> 31
28, -1, 28, -1, -1, -1, -1, -1, // 32 -> 39
-1, -1, 28, 30, 28, -1, -1, -1, // 40 -> 47
-1, -1, -1, -1, -1, -1, -1, -1, // 48 -> 55
-1, -1, -1, -1, -1, -1, -1, -1, // 56 -> 63
} ;

static uint8_t gpioToClkDiv [] =
{
-1, -1, -1, -1, 29, 31, 33, -1, // 0 -> 7
-1, -1, -1, -1, -1, -1, -1, -1, // 8 -> 15
-1, -1, -1, -1, 29, 31, -1, -1, // 16 -> 23
-1, -1, -1, -1, -1, -1, -1, -1, // 24 -> 31
29, -1, 29, -1, -1, -1, -1, -1, // 32 -> 39
-1, -1, 29, 31, 29, -1, -1, -1, // 40 -> 47
-1, -1, -1, -1, -1, -1, -1, -1, // 48 -> 55
-1, -1, -1, -1, -1, -1, -1, -1, // 56 -> 63
} ;


/*
* Functions
@@ -497,93 +557,6 @@ int piBoardRev (void)


/*
* pinMode:
* Sets the mode of a pin to be input, output or PWM output
*********************************************************************************
*/

void pinModeGpio (int pin, int mode)
{
// register int barrier ;

int fSel, shift, alt ;

pin &= 63 ;

fSel = gpioToGPFSEL [pin] ;
shift = gpioToShift [pin] ;

/**/ if (mode == INPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) ; // Sets bits to zero = input
else if (mode == OUTPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (1 << shift) ;
else if (mode == PWM_OUTPUT)
{
if ((alt = gpioToPwmALT [pin]) == 0) // Not a PWM pin
return ;

// Set pin to PWM mode

*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;

delayMicroseconds (110) ; // See comments in pwmSetClockWPi
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;

// Page 107 of the BCM Peripherals manual talks about the GPIO clocks,
// but I'm assuming (hoping!) that this applies to other clocks too.

*(pwm + PWM_CONTROL) = 0 ; // Stop PWM

*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x01 ; // Stop PWM Clock
delayMicroseconds (110) ; // See comments in pwmSetClockWPi

while ((*(clk + PWMCLK_CNTL) & 0x80) != 0) // Wait for clock to be !BUSY
delayMicroseconds (1) ;

*(clk + PWMCLK_DIV) = BCM_PASSWORD | (32 << 12) ; // set pwm div to 32 (19.2/32 = 600KHz)
*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x11 ; // enable clk

delayMicroseconds (110) ; // See comments in pwmSetClockWPi

// Default range register of 1024

*(pwm + PWM0_RANGE) = 1024 ; delayMicroseconds (10) ;
*(pwm + PWM1_RANGE) = 1024 ; delayMicroseconds (10) ;
*(pwm + PWM0_DATA) = 0 ; delayMicroseconds (10) ;
*(pwm + PWM1_DATA) = 0 ; delayMicroseconds (10) ;

// Enable PWMs in balanced mode (default)

*(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE ;

delay (100) ;
}


// When we change mode of any pin, we remove the pull up/downs
// Or we used to... Hm. Commented out now because for some wieird reason,
// it seems to block subsequent attempts to set the pull up/downs and I've
// not quite gotten to the bottom of why this happens
// The down-side is that the pull up/downs are rememberd in the SoC between
// power cycles, so it's going to be a good idea to explicitly set them in
// any new code.
//
// pullUpDnControl (pin, PUD_OFF) ;

}

void pinModeWPi (int pin, int mode)
{
pinModeGpio (pinToGpio [pin & 63], mode) ;
}

void pinModeSys (int pin, int mode)
{
return ;
}


/*
* getAlt:
* Returns the ALT bits for a given port. Only really of-use
* for the gpio readall command (I think)
@@ -825,6 +798,44 @@ void pwmWriteSys (int pin, int value)


/*
* gpioClockSet:
* Set the freuency on a GPIO clock pin
*********************************************************************************
*/

void gpioClockSetGpio (int pin, int freq)
{
int divi, divr, divf ;

pin &= 63 ;
divi = 19200000 / freq ;
divr = 19200000 % freq ;
divf = (int)((double)divr * 4096.0 / 19200000.0) ;

if (divi > 4095)
divi = 4095 ;

*(clk + gpioToClkCon [pin]) = BCM_PASSWORD | GPIO_CLOCK_SOURCE ; // Stop GPIO Clock
while ((*(clk + gpioToClkCon [pin]) & 0x80) != 0) // ... and wait
;

*(clk + gpioToClkDiv [pin]) = BCM_PASSWORD | (divi << 12) | divf ; // Set dividers
*(clk + gpioToClkCon [pin]) = BCM_PASSWORD | 0x10 | GPIO_CLOCK_SOURCE ; // Start Clock
}

void gpioClockSetWPi (int pin, int freq)
{
gpioClockSetGpio (pinToGpio [pin & 63], freq) ;
}

void gpioClockSetSys (int pin, int freq)
{
return ;
}


/*
* setPadDrive:
* Set the PAD driver value
*********************************************************************************
@@ -932,6 +943,65 @@ void pullUpDnControlSys (int pin, int pud)


/*
* pinMode:
* Sets the mode of a pin to be input, output or PWM output
*********************************************************************************
*/

void pinModeGpio (int pin, int mode)
{
// register int barrier ;

int fSel, shift, alt ;

pin &= 63 ;

fSel = gpioToGPFSEL [pin] ;
shift = gpioToShift [pin] ;

/**/ if (mode == INPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) ; // Sets bits to zero = input
else if (mode == OUTPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (1 << shift) ;
else if (mode == PWM_OUTPUT)
{
if ((alt = gpioToPwmALT [pin]) == 0) // Not a PWM pin
return ;

// Set pin to PWM mode

*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;
delayMicroseconds (110) ; // See comments in pwmSetClockWPi

pwmSetModeWPi (PWM_MODE_BAL) ; // Pi default mode
pwmSetRangeWPi (1024) ; // Default range of 1024
pwmSetClockWPi (32) ; // 19.2 / 32 = 600KHz - Also starts the PWM
}
else if (mode == GPIO_CLOCK)
{
if ((alt = gpioToGpClkALT0 [pin]) == 0) // Not a GPIO_CLOCK pin
return ;

// Set pin to GPIO_CLOCK mode and set the clock frequency to 100KHz

*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;
delayMicroseconds (110) ;
gpioClockSetGpio (pin, 100000) ;
}
}

void pinModeWPi (int pin, int mode)
{
pinModeGpio (pinToGpio [pin & 63], mode) ;
}

void pinModeSys (int pin, int mode)
{
return ;
}


/*
* waitForInterrupt:
* Wait for Interrupt on a GPIO pin.
* This is actually done via the /sys/class/gpio interface regardless of
@@ -1229,6 +1299,7 @@ int wiringPiSetup (void)
pullUpDnControl = pullUpDnControlWPi ;
digitalWrite = digitalWriteWPi ;
digitalWriteByte = digitalWriteByteGpio ; // Same code
gpioClockSet = gpioClockSetWPi ;
pwmWrite = pwmWriteWPi ;
setPadDrive = setPadDriveWPi ;
digitalRead = digitalReadWPi ;
@@ -1373,6 +1444,7 @@ int wiringPiSetupGpio (void)
pullUpDnControl = pullUpDnControlGpio ;
digitalWrite = digitalWriteGpio ;
digitalWriteByte = digitalWriteByteGpio ;
gpioClockSet = gpioClockSetGpio ;
pwmWrite = pwmWriteGpio ;
setPadDrive = setPadDriveGpio ;
digitalRead = digitalReadGpio ;
@@ -1413,6 +1485,7 @@ int wiringPiSetupSys (void)
pullUpDnControl = pullUpDnControlSys ;
digitalWrite = digitalWriteSys ;
digitalWriteByte = digitalWriteByteSys ;
gpioClockSet = gpioClockSetSys ;
pwmWrite = pwmWriteSys ;
setPadDrive = setPadDriveSys ;
digitalRead = digitalReadSys ;


+ 6
- 0
wiringPi/wiringPi.h View File

@@ -32,13 +32,18 @@
#define WPI_MODE_PIFACE 3
#define WPI_MODE_UNINITIALISED -1

// Pin modes

#define INPUT 0
#define OUTPUT 1
#define PWM_OUTPUT 2
#define GPIO_CLOCK 3

#define LOW 0
#define HIGH 1

// Pull up/down/none

#define PUD_OFF 0
#define PUD_DOWN 1
#define PUD_UP 2
@@ -85,6 +90,7 @@ extern int (*getAlt) (int pin) ;
extern void (*pullUpDnControl) (int pin, int pud) ;
extern void (*digitalWrite) (int pin, int value) ;
extern void (*digitalWriteByte) (int value) ;
extern void (*gpioClockSet) (int pin, int freq) ;
extern void (*pwmWrite) (int pin, int value) ;
extern void (*setPadDrive) (int group, int value) ;
extern int (*digitalRead) (int pin) ;


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