Messages in this thread | | | Date | Tue, 3 May 2016 12:32:00 +0100 | From | Mark Brown <> | Subject | Re: [RFC 0/7] iio: inv_mpu6050: Support i2c master and external readings |
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On Tue, May 03, 2016 at 02:21:40PM +0300, Crestez Dan Leonard wrote:
> I have a device which has several registers with bits that are a mix of > "cacheable" and "volatile". For example for register SLV4_CTRL:
> - Bit 7 (I2C_SLV4_EN) triggers a transaction with slave 4 when a "1" is > written. The bit is cleared when the transaction is done. > - Bits 0-4 (I2C_MST_DLY) configures the reduced access rate of I2C > slaves relative to the device sample rate. This applies to slaves 0-3 as > well.
> If I2C_MST_DLY was a separate register it could be easily cached by > regmap. Because it's part of a volatile register I have to add a > private_data field caching the value and always write it when triggering > a SLV4 transfer.
> Jonathan was wondering if regmap can still be used somehow instead of > custom caching.
If you want to cache in regmap just write a 0 back to the enable bit after you've set it. [unhandled content-type:application/pgp-signature] | |