The PWM consumer interface

The consumer is the device that actually uses PWM channels. A PWM channel is represented in the kernel as an instance of the struct pwm_device structure:

struct pwm_device { 
   const char *label; 
   unsigned long flags; 
   unsigned int hwpwm; 
   unsigned int pwm; 
   struct pwm_chip *chip; 
   void *chip_data; 
 
  unsigned int period;     /* in nanoseconds */ 
  unsigned int duty_cycle; /* in nanoseconds */ 
  enum pwm_polarity polarity; 
}; 

• label: This is the name of the PWM device
• flags: This represents the flags associated with the PWM device
• hwpw: This is a relative index of the PWM device, local to the chip
• pwm: This is the system global index of the PWM device
• chip: This is a PWM chip, the controller providing the PWM device
• chip_data: This is chip-private data associated with the PWM device

From kernel v4.7, the structure has changed to:

struct pwm_device { 
   const char *label; 
   unsigned long flags; 
   unsigned int hwpwm; 
   unsigned int pwm; 
   struct...