PWM driver for MCF5225x

[trailman]

Yes, this is another PWM driver for MCF5225x, but when I wrote it no driver was available.

Snce this time a driver was posted on the forum by Myke (https://community.freescale.com/message/69804#69804)

I post mine now in cas it would help.

It only has 3 IOCTLs :

- one to init PWM module

- one to init a pin for PWM and set an initial period and duty

- one to update period/duty.

It has been written to drive some fans.

To use it :

- in  mqx/source/include/ioctl.h , add the following #define
#define IO_TYPE_GPTIN              0xNN
where 0xNN is an unused value for your BSP

- in mqx/source/psp/coldfire/mcf5225.h , in mcf5225_pwm_struct, replace :

    uchar    filler[0xFFDB];   

with

    uchar    filler3;
    uchar    PCME;            // PWM PCM Mode Enable register
    uchar    filler[0xFFD9];

- install the driver source files in mqx/source/io

- then use the driver using its simple API :

Install driver :
_io_pwm_install("pwm:");

Open device ;
FILE_PTR fdpwm;
if ((fdpwm = fopen("pwm:", NULL )) == NULL) {
  printf("Opening PWM device driver failed.\n");
}

Configure PWM module :
PWM_DEV_CONFIG_DATA pwm_conf_data;
pwm_conf_data.clock_Sys_to_A_divisor = 0;  /* 2**n, 0<=n<=7 */
pwm_conf_data.clock_Sys_to_B_divisor = 0;  /* 2**n, 0<=n<=7 */
pwm_conf_data.clock_A_to_AS_divisor = 60;   /* 2*n, or 512 if n=0 */
pwm_conf_data.clock_B_to_BS_divisor = 60;   /* 2*n, or 512 if n=0 */
if (ioctl(fdpwm, PWM_IOCTL_CONFIG, &pwm_conf_data)) {
  printf("PWM_IOCTL_CONFIG failed.\n");
}

Configure a pin and set initial period and duty cycle :
pwm_pin_data.pwm_pin = 2;         /* 0-7 */
pwm_pin_data.polarity = 1;        /* 1 for active high */
pwm_pin_data.xS_clock_select = 1; /* 1 for AS/BS clock instead of A/B; A for 0,1,4,5 / B for 2,3,6,7 */
pwm_pin_data.center_aligned = 0;  /* 1 for center aligned */
pwm_pin_data.concatenate = 0;     /* 1 to concatenate odd channel n with channel n-1 */
pwm_pin_data.stop_doze = 0;       /* stop PWM in doze mode */
pwm_pin_data.stop_debug = 0;      /* stop PWM in debug mode */
pwm_pin_data.pcm_enable = 0;      /* 1 to use PCM instead of PWM */
pwm_pin_data.period = 200;        /* 0-255, or 0-65535 if concatenate=1 */
pwm_pin_data.duty = 0;            /* 0-period; 0:0%; period:100% */
if (ioctl(fdpwm, PWM_IOCTL_ENABLE_PIN, &pwm_pin_data)) {
  printf("PWM_IOCTL_ENABLE_PIN failed.\n");
}

Change period and duty cycle :
pwm_change_data.pwm_pin = 2;
pwm_change_data.period = 200;
pwm_change_data.duty = 70; /* 35 % PWM (70 for 200) */
if (ioctl(fdpwm, PWM_IOCTL_CHANGE_DUTY, &pwm_change_data)) {
  printf("PWM_DEV_CHANGE_DUTY_DATA failed.\n");
  _mqx_exit(-1);
}

[trailman]

I found an error in my first post : you must edit mqx/source/include/ioctl.h to add :

  #define IO_TYPE_PWM              0xNN

  where 0xNN is an unused value for your BSP

not IO_TYPE_GPTIN (this was a copy of another post for a GPTIN driver)

[jean-lucpetitpi]

Hello,

This driver is exactly what i need

.....BUT ...

I'm a newby on this forum

and I don't know how to download your PWM driver ?

Any help ?

Thank's

[trailman]

Hi Jean-Luc,

The code as attachment has been lost when freescale moved the forum to its new version.

I've rebuilt the .zip today, please find it attached below

Gilles

[jean-lucpetitpi]

Hello,

So nice, so quickly, that's all what I want.

Merci pour l'entraide, à charge de revanche.

@+

[trailman · Accepted solution]

Note : The "concatenate" mode (16 bit PWM) has never been tested