Messages in this thread | | | Date | Fri, 25 Feb 2011 10:04:59 +0800 | From | Thomas Chou <> | Subject | Re: [PATCH v6] i2c-gpio: add devicetree support |
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Hi Grant,
On 02/25/2011 12:22 AM, Grant Likely wrote: >> +Required properties: >> +- compatible : should be "i2c-gpio". >> +- gpios : should specify GPIOs used for SDA and SCL lines, in that order. >> +Optional properties: >> +- sda-is-open-drain : present if SDA gpio is open-drain. >> +- scl-is-open-drain : present if SCL gpio is open-drain. >> +- scl-is-output-only : present if the output driver for SCL cannot be >> + turned off. this will prevent clock stretching from working. >> +- speed-hz : SCL frequency. > > Hi Thomas, > > One nitpick; I just looked, and other i2c controllers are already > using 'clock-frequency' instead of 'speed-hz' for the speed of the > bus. I'd like to see this patch use the same terminology.
I studied 'clock-frequency' usage of existing i2c drivers before working on this patch.
i2c-ibm_iic.c, i2c-mpc.c, i2c-ocores.c : use as bus clock frequency input to the core.
i2c-cpm.c : use as i2c SCL output frequency.
Most other non-i2c drivers use clock-frequency as bus clock frequency input, too.
I think the SCL freq usage in i2c-cpm.c is confusing. So I would suggest we borrow 'speed-hz' from spi subsystem, which means the clock freq output on the peripheral bus.
Best regards, Thomas
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