Re: [PATCH v5 11/13] drm/i915/icl: Add macros for MMIO of DSI transcoder registers

From: Madhav Chauhan <madhav.chauhan@intel.com>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>,
	intel-gfx@lists.freedesktop.org, paulo.r.zanoni@intel.com,
	rodrigo.vivi@intel.com
Subject: Re: [PATCH v5 11/13] drm/i915/icl: Add macros for MMIO of DSI transcoder registers
Date: Fri, 14 Sep 2018 18:57:23 +0530	[thread overview]
Message-ID: <6da1661c-3d19-800c-3602-d7ed34bfcfe8@intel.com> (raw)
In-Reply-To: <241bf36a-f36f-7b09-4e96-96345288d5c1@intel.com>

On 9/14/2018 6:36 PM, Madhav Chauhan wrote:
> On 9/14/2018 5:55 PM, Ville Syrjälä wrote:
>> On Fri, Sep 14, 2018 at 11:42:33AM +0530, Madhav Chauhan wrote:
>>> On 9/12/2018 11:30 PM, Ville Syrjälä wrote:
>>>> On Wed, Sep 12, 2018 at 03:06:41PM +0530, Madhav Chauhan wrote:
>>>>> On 7/19/2018 9:52 PM, Ville Syrjälä wrote:
>>>>>> On Tue, Jul 10, 2018 at 03:10:12PM +0530, Madhav Chauhan wrote:
>>>>>>> This patch adds _MMIO_DSI and _DSI_TRANS macros for accessing
>>>>>>> DSI transcoder registers.
>>>>>>>
>>>>>>> Credits-to: Jani N
>>>>>>>
>>>>>>> Cc: Jani Nikula <jani.nikula@intel.com>
>>>>>>> Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
>>>>>>> ---
>>>>>>>     drivers/gpu/drm/i915/i915_reg.h | 5 +++++
>>>>>>>     1 file changed, 5 insertions(+)
>>>>>>>
>>>>>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>>>>>>> b/drivers/gpu/drm/i915/i915_reg.h
>>>>>>> index 1d13ba9..62bc76e 100644
>>>>>>> --- a/drivers/gpu/drm/i915/i915_reg.h
>>>>>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>>>>>>> @@ -9576,6 +9576,11 @@ enum skl_power_gate {
>>>>>>>     #define _MIPI_PORT(port, a, c)    (((port) == PORT_A) ? a : 
>>>>>>> c)    /* ports A and C only */
>>>>>>>     #define _MMIO_MIPI(port, a, c) _MMIO(_MIPI_PORT(port, a, c))
>>>>>>>     +/* gen11 DSI */
>>>>>>> +#define _DSI_TRANS(tc, dsi0, dsi1)    (((tc) == 
>>>>>>> TRANSCODER_DSI_0) ?    \
>>>>>>> +                     (dsi0) : (dsi1))
>>>>>> _PIPE() etc. should result in slughtly better code IIRC.
>>>>> Can you please clarify on this??
>>>> Plenty of examples in i915_reg.h for using _PIPE().
>>> I meant what are advantages of using _PIPE against the current 
>>> approach??
>> Uniform style, better generated code usually (look at the generated asm
>> to verify).
>
> Got it.
>
>>
>>> Also if we use _PIPE, are you suggesting something below:
>>> #define _MMIO_DSI(tc, dsi0, dsi1)    _MMIO_PIPE(tc, dsi0, dsi1))
>>> Using above macro we will get wrong DSI addresses as TRANS_DSI_0 
>>> value is 5.
>> (tc)-TRANSCODER_DSI_0

Can we use _MMIO_TRANS here, _TRANS & _PIPE have same definition??
That will emphasize that these registers are transcoder specific not the 
PIPE.

Regards,
Madhav

>
> Thanks for clarification Ville, will use _PIPE().
>
> Regards,
> Madhav
>
>>
>>> Or do you mean to use PORT instead of TRANS_DSI_0/1 to _MMIO_DSI??
>>>
>>> Regards,
>>> Madhav
>>>
>>>>> Regards,
>>>>> Madhav
>>>>>
>>>>>>> +#define _MMIO_DSI(tc, dsi0, dsi1)    _MMIO(_DSI_TRANS(tc, dsi0, 
>>>>>>> dsi1))
>>>>>>> +
>>>>>>>     #define MIPIO_TXESC_CLK_DIV1 _MMIO(0x160004)
>>>>>>>     #define  GLK_TX_ESC_CLK_DIV1_MASK            0x3FF
>>>>>>>     #define MIPIO_TXESC_CLK_DIV2 _MMIO(0x160008)
>>>>>>> -- 
>>>>>>> 2.7.4
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Intel-gfx mailing list
>>>>>>> Intel-gfx@lists.freedesktop.org
>>>>>>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>

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