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) ;
#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
#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
#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
#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)
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
#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,
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
} ;
+// 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
-/*
- * 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
}
+/*
+ * 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
}
+/*
+ * 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.
pullUpDnControl = pullUpDnControlWPi ;
digitalWrite = digitalWriteWPi ;
digitalWriteByte = digitalWriteByteGpio ; // Same code
+ gpioClockSet = gpioClockSetWPi ;
pwmWrite = pwmWriteWPi ;
setPadDrive = setPadDriveWPi ;
digitalRead = digitalReadWPi ;
pullUpDnControl = pullUpDnControlGpio ;
digitalWrite = digitalWriteGpio ;
digitalWriteByte = digitalWriteByteGpio ;
+ gpioClockSet = gpioClockSetGpio ;
pwmWrite = pwmWriteGpio ;
setPadDrive = setPadDriveGpio ;
digitalRead = digitalReadGpio ;
pullUpDnControl = pullUpDnControlSys ;
digitalWrite = digitalWriteSys ;
digitalWriteByte = digitalWriteByteSys ;
+ gpioClockSet = gpioClockSetSys ;
pwmWrite = pwmWriteSys ;
setPadDrive = setPadDriveSys ;
digitalRead = digitalReadSys ;
~ianmdlvl / wiringPi.git / commitdiff