Problem with s3c24xx pwm driver

Vasily Khoruzhick anarsoul at gmail.com
Thu Sep 24 04:54:56 EDT 2009


В сообщении от 24 сентября 2009 01:25:46 автор Eric Miao написал:

> No, it doesn't.
> 
> So my suggestion at the moment is that you may:
> 
> 1. try dump the registers after pwm_enable() and see if all are setup
> correctly,
> 
> 2. and make sure those registers are write-able at that time (some
> SoC doesn't allow register writing when the controller is disabled).
> 

Here's a trace with my comments, but I can't see anything wrong in this trace:

/* Configuring backlight level */
pwm_config:271: TCMPB, wrote: 0000010a, read: 0000010a <- Configure duty
pwm_config:274: TCNTB, wrote: 0000012a, read: 0000012a <- Configure period
pwm_config:281: TCON, wrote: 0051990f, read: 0051990f <- Set manual update 
flag
pwm_config:286: TCON, wrote: 0051990d, read: 0051990d <- Clear manual update 
flag
pwm_enable:149: TCON, wrote: 0051990d, read: 0051990d <- Enable called each 
time if backlight level != 0
/* Configuring backlight level */
pwm_config:271: TCMPB, wrote: 000000a3, read: 000000a3
pwm_config:274: TCNTB, wrote: 0000012a, read: 0000012a
pwm_config:281: TCON, wrote: 0051990f, read: 0051990f
pwm_config:286: TCON, wrote: 0051990d, read: 0051990d
pwm_enable:149: TCON, wrote: 0051990d, read: 0051990d
/* Configuring backlight level */
pwm_config:271: TCMPB, wrote: 00000112, read: 00000112
pwm_config:274: TCNTB, wrote: 0000012a, read: 0000012a
pwm_config:281: TCON, wrote: 0051990f, read: 0051990f
pwm_config:286: TCON, wrote: 0051990d, read: 0051990d
pwm_enable:149: TCON, wrote: 0051990d, read: 0051990d
/* Works fine until next sequence */
/* Disabling backlight */
pwm_config:271: TCMPB, wrote: 00000129, read: 00000129
pwm_config:274: TCNTB, wrote: 0000012a, read: 0000012a
pwm_config:281: TCON, wrote: 0051990f, read: 0051990f
pwm_config:286: TCON, wrote: 0051990d, read: 0051990d
pwm_disable:170: TCON, wrote: 0051990c, read: 0051990c <- Clear start flag

/* Enabling backlight back, but it doesn't work :( */
pwm_config:271: TCMPB, wrote: 00000124, read: 00000124 <- Configure duty
pwm_config:274: TCNTB, wrote: 0000012a, read: 0000012a <- Configure period
pwm_config:281: TCON, wrote: 0051990e, read: 0051990e <- Set manual update 
flag
pwm_config:286: TCON, wrote: 0051990c, read: 0051990c <- Clear manual update 
flag
pwm_enable:149: TCON, wrote: 0051990d, read: 0051990d <- Set start flag
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