Messages in this thread | | | Date | Mon, 6 Mar 2023 23:57:04 +0100 | Subject | Re: [PATCH 02/10] mfd: rt5033: Fix chip revision readout | From | Jakob Hauser <> |
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Hi Lee,
On 06.03.23 10:18, Lee Jones wrote: > On Sun, 05 Mar 2023, Jakob Hauser wrote: > >> Hi Lee, >> >> On 05.03.23 11:47, Lee Jones wrote: >>> On Tue, 28 Feb 2023, Jakob Hauser wrote: >>> >>>> After reading the data from the DEVICE_ID register, mask 0x0f needs to be >>>> applied to extract the revision of the chip [1]. >>>> >>>> The other part of the DEVICE_ID register, mask 0xf0, is a vendor identification >>>> code. That's how it is set up at similar products of Richtek, e.g. RT9455 [2] >>>> page 21 top. >>>> >>>> [1] https://github.com/msm8916-mainline/linux-downstream/blob/GT-I9195I/drivers/mfd/rt5033_core.c#L484 >>>> [2] https://www.richtek.com/assets/product_file/RT9455/DS9455-00.pdf >>>> >>>> Signed-off-by: Jakob Hauser <jahau@rocketmail.com> >>>> --- >>>> drivers/mfd/rt5033.c | 8 +++++--- >>>> include/linux/mfd/rt5033-private.h | 4 ++++ >>>> 2 files changed, 9 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/mfd/rt5033.c b/drivers/mfd/rt5033.c >>>> index 8029d444b794..d32467174cb5 100644 >>>> --- a/drivers/mfd/rt5033.c >>>> +++ b/drivers/mfd/rt5033.c >>>> @@ -55,7 +55,8 @@ static const struct regmap_config rt5033_regmap_config = { >>>> static int rt5033_i2c_probe(struct i2c_client *i2c) >>>> { >>>> struct rt5033_dev *rt5033; >>>> - unsigned int dev_id; >>>> + unsigned int data; >>> >>> In terms of nomenclature, this is a regression. >>> >>> 'data' is a terrible variable name. Why not keep it as-is? >> >> While not having a datasheet for RT5033 available, in similar products like >> RT9455 the register is called "Device ID", the first part of that is >> "VENDOR_ID" and the second part "CHIP_REV", [1] page 23 top. Or in RT5036 >> preliminary data sheet the register is called "ID", the first part >> "VENDOR_ID" and the second part "CHIP_REV_ID", [2] page 27 top. >> >> I wanted to avoid confusion between "dev_id" and "chip_rev". Therefore in >> the patch it's written as getting some "data" from the register and extract >> "chip_rev" from that data. >> >> I could change it to "reg_data"? Or something in that direction? I still >> think that getting "chip_rev" out of "dev_id" would be confusing. > > You're reading from a register called RT5033_REG_DEVICE_ID. I don't see > any reason why the variable you read into can't reflect that.
OK, I'll use "dev_id" and "chip_rev" for the variable names.
...
Kind regards, Jakob
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