linux-kernel - Re: [PATCH v3 3/3] drm/bridge: it6505: Add MCCS support

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]

Message-ID: <lxh4anqlrrfqs5iljf5iughavosvqt6dzcff6flcoruimxgeq2@d5ig536voy5q>
Date: Tue, 24 Sep 2024 12:59:21 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Hermes.Wu@....com.tw
Cc: treapking@...omium.org, Kenneth.Hung@....com.tw, 
	andrzej.hajda@...el.com, neil.armstrong@...aro.org, rfoss@...nel.org, 
	Laurent.pinchart@...asonboard.com, jonas@...boo.se, jernej.skrabec@...il.com, 
	maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de, airlied@...il.com, 
	simona@...ll.ch, dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/3] drm/bridge: it6505: Add MCCS support

On Tue, Sep 24, 2024 at 03:52:34AM GMT, Hermes.Wu@....com.tw wrote:
> >On Mon, Sep 23, 2024 at 05:48:29PM GMT, Hermes Wu wrote:
> >> From: Hermes Wu <Hermes.wu@....com.tw>
> >> 
> >> Changes in v3:
> >>  -remove non used definition for aux i2x cmd reply
> >> 
> >> Add Aux-I2C functionality to support MCCS.
> >> 
> >> Signed-off-by: Hermes Wu <Hermes.wu@....com.tw>
> >> ---
> >>  drivers/gpu/drm/bridge/ite-it6505.c | 174 
> >> +++++++++++++++++++++++++++-
> >>  1 file changed, 172 insertions(+), 2 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/bridge/ite-it6505.c 
> >> b/drivers/gpu/drm/bridge/ite-it6505.c
> >> index 156440c6517e..5aedc5570739 100644
> >> --- a/drivers/gpu/drm/bridge/ite-it6505.c
> >> +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> >> @@ -125,6 +125,9 @@
> >>  #define REG_AUX_ADR_16_19 0x26
> >>  #define REG_AUX_OUT_DATA0 0x27
> >>  
> >> +#define REG_AUX_I2C_ADR 0x25
> >> +#define REG_AUX_I2C_OP 0x26
> >> +
> >
> >Are these registers CMD-specific? Because I see that you already have defines for 0x25 and 0x26.
> >
> 
> The AUX packet i2c into aux transfer frames,
> and I think it's easier to understand how it6505_aux_i2c_operation() packet i2c request into aux frame.

I'm really sorry, but I don't think I can parse this or how this answers
my question. If for the user I2C a part of the register space gets
repurposed, please comment that before the defines (and maybe separate
such defines so that it's obvious to anybody reading the driver).

> 
> >>  #define REG_AUX_CMD_REQ 0x2B
> >>  #define AUX_BUSY BIT(5)
> >>  
> >> @@ -266,6 +269,19 @@
> >>  #define REG_SSC_CTRL1 0x189
> >>  #define REG_SSC_CTRL2 0x18A
> >>  
> >> +#define REG_AUX_USER_CTRL 0x190
> >> +#define EN_USER_AUX BIT(0)
> >> +#define USER_AUX_DONE BIT(1)
> >> +#define AUX_EVENT BIT(4)
> >> +
> >> +#define REG_AUX_USER_DATA_REC 0x191
> >> +#define M_AUX_IN_REC   0xF0
> >> +#define M_AUX_OUT_REC  0x0F
> >> +
> >> +#define REG_AUX_USER_TXB 0x190
> >
> >And two defines for 0x190 too.
> >
> >> +#define REG_AUX_USER_REPLY 0x19A
> >> +#define REG_AUX_USER_RXB(n) (n + 0x19B)
> >> +
> >>  #define RBR DP_LINK_BW_1_62
> >>  #define HBR DP_LINK_BW_2_7
> >>  #define HBR2 DP_LINK_BW_5_4

-- 
With best wishes
Dmitry