[PATCH v2 26/27] drm/tegra: Add DSI support

[Stephen Warren]

On 10/15/2013 02:33 AM, Thierry Reding wrote:
> On Mon, Oct 14, 2013 at 12:16:48PM -0600, Stephen Warren wrote:
>> On 10/14/2013 07:55 AM, Thierry Reding wrote:
>>> On Fri, Oct 11, 2013 at 04:43:35PM -0600, Stephen Warren
>>> wrote:
>>>> On 10/07/2013 02:34 AM, Thierry Reding wrote:
>>>>> This commit adds support for both DSI outputs found on
>>>>> Tegra. Only very minimal functionality is implemented, so
>>>>> advanced features like ganged mode won't work.
>>>>> 
>>>>> Due to the lack of other test hardware, some sections of
>>>>> the driver are hardcoded to work with Dalmore.
>>>> 
>>>>> diff --git a/drivers/gpu/drm/tegra/dsi.c
>>>>> b/drivers/gpu/drm/tegra/dsi.c
>>>> 
>>>>> +static int tegra_dsi_show_regs(struct seq_file *s, void
>>>>> *data) +{ +	struct drm_info_node *node = s->private; +
>>>>> struct tegra_dsi *dsi = node->info_ent->data; + +#define
>>>>> DUMP_REG(name)						\ +	seq_printf(s, "%-32s %#05x
>>>>> %08lx\n", #name, name,	\ +		   tegra_dsi_readl(dsi, name)) 
>>>>> + +	DUMP_REG(DSI_INCR_SYNCPT);
>>>> 
>>>> Does it make sense to use an MMIO regmap instead? That way,
>>>> you get all the debugfs files for free...
>>> 
>>> As far as I know, regmap doesn't give you the symbolic names
>>> for the registers. I find that a rather useful feature because
>>> it allows to easily compare the registers to the ones in our
>>> downstream kernels.
>> 
>> True. However, we should really be writing user-space scripts to
>> encode that information. Such a script could be useful e.g. if
>> reading the information directly from /dev/mem or JTAG too, and
>> bloating the kernel with debug strings doesn't seem like a great
>> idea.
> 
> I don't agree. While I see some value in having such userspace
> scripts, having the symbolic names in debugfs allows anyone to look
> at a readable form of the data without having to have access to
> those scripts. Besides it's called *debug*fs for a purpose, isn't
> it? There's plenty of edited data that's not just a plain dump of
> data.

Perhaps you should work to enhance regmap's debugfs files to support
optionally naming registers?