pi_pwm.h

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#ifndef PI_PWM_H
#define PI_PWM_H


#define BCM2708_PERI_BASE   0x20000000
#define CLOCK_BASE          (BCM2708_PERI_BASE + 0x101000)  /* Clocks */
#define GPIO_BASE           (BCM2708_PERI_BASE + 0x200000)  /* GPIO   */
#define PWM_BASE            (BCM2708_PERI_BASE + 0x20C000)  /* PWM    */

/* PWM Registers */
#define GPIO_SET0   *(gpio+7)   /* Set GPIO high bits 0-31 */
#define GPIO_SET1   *(gpio+8)   /* Set GPIO high bits 32-53 */

#define GPIO_CLR0   *(gpio+10)  /* Set GPIO low bits 0-31 */
#define GPIO_CLR1   *(gpio+11)  /* Set GPIO low bits 32-53 */

#define PWMCLK_CNTL  *(clk+40)
#define PWMCLK_DIV   *(clk+41)

#define PWM_CONTROL *pwm
#define PWM_STATUS  *(pwm+1)
#define PWM0_RANGE  *(pwm+4)
#define PWM1_RANGE  *(pwm+8)
#define PWM0_DATA   *(pwm+5)
#define PWM1_DATA   *(pwm+9)

/* PWM Control register bits */
#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_OFFSTATE   0x0008  /* Ouput Off state */
#define PWM0_REPEATFF   0x0004  /* Repeat last value if FIFO empty */
#define PWM0_SERIAL     0x0002  /* Run in serial mode */
#define PWM0_ENABLE     0x0001  /* Channel Enable */

#define PWM_CLRFIFO     0x0040  /* Clear FIFO (Self clearing bit) */

/* PWM status bits I need */
#define PWMS_BUSERR     0x0100  /* Register access was too fast */
/* (Write to clear it) */


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


/* GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y) */
#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
#define OUT_GPIO(g) *(gpio+((g)/10)) |=  (1<<(((g)%10)*3))
#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))

#define GPIO_SET0     *(gpio+7)     /* Set GPIO high bits 0-31 */
#define GPIO_SET1     *(gpio+8)     /* Set GPIO high bits 32-53 */

#define GPIO_CLR0     *(gpio+10)    /* Set GPIO low bits 0-31 */
#define GPIO_CLR1     *(gpio+11)    /* Set GPIO low bits 32-53 */
#define GPIO_PULL     *(gpio+37)    /* Pull up/pull down */
#define GPIO_PULLCLK0 *(gpio+38)    /* Pull up/pull down clock */


/* I/O access */

// Range for the PWM module
const unsigned int PWM_MAX = 1024;

// FIXME: Remove these?
volatile unsigned int *gpio;
volatile unsigned int *pwm;
volatile unsigned int *clk;

int pwm_init ();
void pwm_mode (unsigned int mode);
void pwm_value (unsigned int value);
void pwm_release ();

#endif