Messages in this thread | | | Date | Mon, 24 Feb 2020 11:27:14 +0000 | From | Lee Jones <> | Subject | Re: [RESEND PATCH 1/2] mfd: da9063: Fix revision handling to correctly select reg tables |
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On Mon, 24 Feb 2020, Adam Thomson wrote:
> On 24 February 2020 09:57, Lee Jones wrote: > > > On Fri, 24 Jan 2020, Adam Thomson wrote: > > > > > The current implementation performs checking in the i2c_probe() > > > function of the variant_code but does this immediately after the > > > containing struct has been initialised as all zero. This means the > > > check for variant code will always default to using the BB tables > > > and will never select AD. The variant code is subsequently set > > > by device_init() and later used by the RTC so really it's a little > > > fortunate this mismatch works. > > > > > > This update creates an initial temporary regmap instantiation to > > > simply read the chip and variant/revision information (common to > > > all revisions) so that it can subsequently correctly choose the > > > proper regmap tables for real initialisation. > > > > IIUC, you have a dependency issue whereby the device type is required > > before you can select the correct Regmap configuration. Is that > > correct? > > Yep, spot on. > > > If so, using Regmap for the initial register reads sounds like > > over-kill. What's stopping you simply using raw reads before the > > Regmap is instantiated? > > Actually nothing and I did consider this at the start. Nice thing with regmap > is it's all tidily contained and provides the page swapping mechanism to access > higher page registers like the variant information. Given this is only once at > probe time it felt like this was a reasonable solution. However if you're not > keen I can update to use raw access instead.
It would be nice to compare the 2 solutions side by side. I can't see the raw reads of a few device-ID registers being anywhere near 170 lines though.
> > > Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com> > > > --- > > > drivers/mfd/da9063-core.c | 31 ------- > > > drivers/mfd/da9063-i2c.c | 167 +++++++++++++++++++++++++++++++- > > --- > > > include/linux/mfd/da9063/registers.h | 15 ++-- > > > 3 files changed, 160 insertions(+), 53 deletions(-) > >
-- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
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