Re: [PATCH v3 2/4] gpio: pca953x: add register definitions for pcal6524 and fix address calculation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Apr 10, 2018 at 7:07 PM, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
> PCAL chips ("L" seems to stand for "latched") have additional
> registers starting at address 0x40 to control the latches,
> interrupt mask, pull-up and pull down etc.
>
> The constants are so far defined in a way that they fit for
> the pcal9555a when shifted by the number of banks, i.e. multiplied
> by 2.
>
> Now the pcal6524 has 3 banks which means the relative offset
> must be multiplied by 4 which gives a wrong result if not done
> carefully, since the base offset is already included in the offset.
>
> For the basic registers shared with all pca93xx/tca64xx chips
> there is no such offset.
>
> Therefore, we add code to adjust the register number for exended
> registers to the 24 bit accessor functions.
>
> And we add additional register offset constants (not yet used by
> the driver code) which are specific to the pcal6524.
>

First of all, as I said, please split this to two patches. Don't mix the things.


> +       /* adjust register address for pcal6524 */
> +       if (reg >= PCAL953X_OUT_STRENGTH)
> +               reg -= PCAL953X_OUT_STRENGTH >> 1;
> +

Give me some days to think about it.

-- 
With Best Regards,
Andy Shevchenko
--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux SPI]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux