Messages in this thread | | | Date | Tue, 9 Apr 2013 12:28:36 +0300 | From | Mika Westerberg <> | Subject | Re: [5/7] i2c-designware: enable/disable the controller properly |
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On Tue, Apr 09, 2013 at 11:09:14AM +0200, Wolfram Sang wrote: > > > +static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable) > > +{ > > + int timeout = 100; > > + > > + do { > > + dw_writel(dev, enable, DW_IC_ENABLE); > > + if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable) > > + return; > > + > > + usleep_range(25, 250); > > This would wait 25ms max. Is there a timeout value specified in the docs?
The datasheet says something like:
1. Define a timer interval (t_i2c_poll) equal 10 times the highest signaling period. For 400kHz this is 25us.
2. Define max timeout parameter, MAX_T_POLL_COUNT, such that if any repeated operation exeeds this maximum, an error is reported.
In this case I have:
t_i2c_poll = 25 (to 250 us) MAX_T_POLL_COUNT = 100
> > + } while (timeout-- > 0); > > while (timeout--)?
OK, thanks.
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