linux-kernel - RE: [PATCH v2 07/12] i2c: riic: Define individual arrays to describe the register offsets

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 28 Jun 2024 10:49:16 +0000
From: Biju Das <biju.das.jz@...renesas.com>
To: Claudiu.Beznea <claudiu.beznea@...on.dev>, Chris Brandt
	<Chris.Brandt@...esas.com>, "andi.shyti@...nel.org" <andi.shyti@...nel.org>,
	"robh@...nel.org" <robh@...nel.org>, "krzk+dt@...nel.org"
	<krzk+dt@...nel.org>, "conor+dt@...nel.org" <conor+dt@...nel.org>,
	"geert+renesas@...der.be" <geert+renesas@...der.be>, "magnus.damm@...il.com"
	<magnus.damm@...il.com>, "mturquette@...libre.com" <mturquette@...libre.com>,
	"sboyd@...nel.org" <sboyd@...nel.org>, "p.zabel@...gutronix.de"
	<p.zabel@...gutronix.de>, "wsa+renesas@...g-engineering.com"
	<wsa+renesas@...g-engineering.com>
CC: "linux-renesas-soc@...r.kernel.org" <linux-renesas-soc@...r.kernel.org>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-clk@...r.kernel.org" <linux-clk@...r.kernel.org>, Claudiu Beznea
	<claudiu.beznea.uj@...renesas.com>
Subject: RE: [PATCH v2 07/12] i2c: riic: Define individual arrays to describe
 the register offsets

Hi Claudiu,

> -----Original Message-----
> From: claudiu beznea <claudiu.beznea@...on.dev>
> Sent: Friday, June 28, 2024 11:25 AM
> Subject: Re: [PATCH v2 07/12] i2c: riic: Define individual arrays to describe the register offsets
> 
> 
> 
> On 28.06.2024 11:24, Biju Das wrote:
> > Hi Claudiu,
> >
> >> -----Original Message-----
> >> From: claudiu beznea <claudiu.beznea@...on.dev>
> >> Sent: Friday, June 28, 2024 9:13 AM
> >> Subject: Re: [PATCH v2 07/12] i2c: riic: Define individual arrays to
> >> describe the register offsets
> >>
> >>
> >>
> >> On 28.06.2024 11:09, Biju Das wrote:
> >>>
> >>> Hi Claudiu,
> >>>
> >>>> -----Original Message-----
> >>>> From: claudiu beznea <claudiu.beznea@...on.dev>
> >>>> Sent: Friday, June 28, 2024 9:03 AM
> >>>> Subject: Re: [PATCH v2 07/12] i2c: riic: Define individual arrays
> >>>> to describe the register offsets
> >>>>
> >>>>
> >>>>
> >>>> On 28.06.2024 10:55, Biju Das wrote:
> >>>>> Hi Claudiu,
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: claudiu beznea <claudiu.beznea@...on.dev>
> >>>>>> Sent: Friday, June 28, 2024 8:32 AM
> >>>>>> Subject: Re: [PATCH v2 07/12] i2c: riic: Define individual arrays
> >>>>>> to describe the register offsets
> >>>>>>
> >>>>>> Hi, Biju,
> >>>>>>
> >>>>>> On 28.06.2024 08:59, Biju Das wrote:
> >>>>>>> Hi Claudiu,
> >>>>>>>
> >>>>>>>> -----Original Message-----
> >>>>>>>> From: Claudiu <claudiu.beznea@...on.dev>
> >>>>>>>> Sent: Tuesday, June 25, 2024 1:14 PM
> >>>>>>>> Subject: [PATCH v2 07/12] i2c: riic: Define individual arrays
> >>>>>>>> to describe the register offsets
> >>>>>>>>
> >>>>>>>> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
> >>>>>>>>
> >>>>>>>> Define individual arrays to describe the register offsets. In
> >>>>>>>> this way we can describe different IP variants that share the
> >>>>>>>> same register offsets but have differences in other characteristics.
> >>>>>>>> Commit prepares for the addition
> >>>>>> of fast mode plus.
> >>>>>>>>
> >>>>>>>> Signed-off-by: Claudiu Beznea
> >>>>>>>> <claudiu.beznea.uj@...renesas.com>
> >>>>>>>> ---
> >>>>>>>>
> >>>>>>>> Changes in v2:
> >>>>>>>> - none
> >>>>>>>>
> >>>>>>>>  drivers/i2c/busses/i2c-riic.c | 58
> >>>>>>>> +++++++++++++++++++----------------
> >>>>>>>>  1 file changed, 31 insertions(+), 27 deletions(-)
> >>>>>>>>
> >>>>>>>> diff --git a/drivers/i2c/busses/i2c-riic.c
> >>>>>>>> b/drivers/i2c/busses/i2c-riic.c index
> >>>>>>>> 9fe007609076..8ffbead95492 100644
> >>>>>>>> --- a/drivers/i2c/busses/i2c-riic.c
> >>>>>>>> +++ b/drivers/i2c/busses/i2c-riic.c
> >>>>>>>> @@ -91,7 +91,7 @@ enum riic_reg_list {  };
> >>>>>>>>
> >>>>>>>>  struct riic_of_data {
> >>>>>>>> -	u8 regs[RIIC_REG_END];
> >>>>>>>> +	const u8 *regs;
> >>>>>>>
> >>>>>>>
> >>>>>>> Since you are touching this part, can we drop struct and Use u8*
> >>>>>>> as device_data instead?
> >>>>>>
> >>>>>> Patch 09/12 "i2c: riic: Add support for fast mode plus" adds a
> >>>>>> new member to struct
> >>>> riic_of_data.
> >>>>>> That new member is needed to differentiate b/w hardware versions
> >>>>>> supporting fast mode plus based on compatible.
> >>>>>
> >>>>> Are we sure RZ/A does not support fast mode plus?
> >>>>
> >>>> From commit description of patch 09/12:
> >>>>
> >>>> Fast mode plus is available on most of the IP variants that RIIC
> >>>> driver is working with. The exception is (according to HW manuals
> >>>> of the SoCs where this IP is
> >> available) the Renesas RZ/A1H.
> >>>> For this, patch introduces the struct riic_of_data::fast_mode_plus.
> >>>>
> >>>> I checked the manuals of all the SoCs where this driver is used.
> >>>>
> >>>> I haven't checked the H/W manual?
> >>>>
> >>>> On the manual I've downloaded from Renesas web site the FMPE bit of
> >>>> RIICnFER is not available on RZ/A1H.
> >>>
> >>> I just found RZ/A2M manual, it supports FMP and register layout looks similar to RZ/G2L.
> >>
> >> I introduced struct riic_of_data::fast_mode_plus because of RZ/A1H.
> >
> > Maybe make the register layout as per SoC
> >
> > RZ/A1 --> &riic_rz_a_info
> > RZ/A2 and RZ/{G2L,G2LC,V2L,G2UL,FIVE} --> &riic_rz_g2_info RZ/G3S and
> > RZ/V2H --> &riic_rz_v2h_info
> 
> Sorry, but I don't understand. Patch 09/12 already does that but a bit
> differently:

Now register layout is added to differentiate the SoCs for adding support
to RZ/G3S and this layout should match with the hardware manual for all supported SoCs.
Currently it is wrong for RZ/A2 SoC, while you fixed it for all other SoCs.

> 
> RZ/{G2L, G2LC, G2UL, V2L, FIVE} -> riic_rz_g2_info RZ/G3S and RZ/V2H -> riic_rz_v2h_info Everything
> else: riic_rz_a_info
> 
> I don't have anything at hand to test the "everything else" thus I enabled it for RZ/{G2L, G2LC,
> G2UL, V2L, FIVE}, RZ/G3S and RZ/V2H.

You don't need to test, as the existing other users don't have FMP+ enabled in device tree.

Cheers,
Biju