Re: [PATCH v2 2/2] drm/panfrost: Add support for Mali on the MT8188 SoC

From: AngeloGioacchino Del Regno
Date: Wed Jun 05 2024 - 07:45:05 EST


Il 05/06/24 11:18, Steven Price ha scritto:
On 04/06/2024 13:39, AngeloGioacchino Del Regno wrote:
MediaTek MT8188 has a Mali-G57 MC3 (Valhall-JM): add a new
compatible and platform data using the same supplies and the
same power domain lists as MT8183 (one regulator, three power
domains).

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_drv.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index ef9f6c0716d5..4e2d9f671a0d 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -777,6 +777,14 @@ static const struct panfrost_compatible mediatek_mt8186_data = {
.pm_features = BIT(GPU_PM_CLK_DIS) | BIT(GPU_PM_VREG_OFF),
};
+static const struct panfrost_compatible mediatek_mt8188_data = {
+ .num_supplies = ARRAY_SIZE(mediatek_mt8183_b_supplies) - 1,
+ .supply_names = mediatek_mt8183_b_supplies,

I think this is a little confusing. Ideally we'd drop the existing
mediatek_xxx_supplies which are the same as default_supplies and just
use that instead.

+ .num_pm_domains = ARRAY_SIZE(mediatek_mt8183_pm_domains),
+ .pm_domain_names = mediatek_mt8183_pm_domains,

We'd want at least a comment explaining that this isn't a typo (i.e. /*
mt8188 uses the same pm domains as mt8183 */). But I'm also wondering if
it would be sensible to simply have one domain list, something like:

--->8---
static const char * const mediatek_pm_domains[] = { "core0", "core1",
"core2", "core3",
"core4" };

static const struct panfrost_compatible mediatek_mt8183_data = {
...
.num_pm_domains = 3,
.pm_domain_names = mediatek_pm_domains,
};
...
static const struct panfrost_compatible mediatek_mt8186_data = {
...
.num_pm_domains = 2,
.pm_domain_names = mediatek_pm_domains,
};
...
static const struct panfrost_compatible mediatek_mt8188_data = {
...
.num_pm_domains = 3,
.pm_domain_names = mediatek_pm_domains,
};
...
static const struct panfrost_compatible mediatek_mt8192_data = {
...
.num_pm_domains = 5,
.pm_domain_names = mediatek_pm_domains,
};
--->8---

OTOH what you've got it no worse than what we already had, so it's up to
you whether you want to tidy this up or just add a comment so it doesn't
look like there's a typo.


I didn't disclose my plan, but you've already shown part of it, so seeing that
you preventively agree with at least part of that is fun :-)

I surely won't be able to do what I want to do for *this* cycle as I'm mostly
sure that I won't have time for this in the next 3 weeks - but anyway....

What I was thinking is that we should either look for a number of power domains
limited by a max power domains definition (that should already be present somewhere
in panfrost if I recall correctly) without even caring about the actual power
domain names, or we should look for a number of PDs having any name matching,
in a for loop, snprintf(*something, sizeof(something), "core%d", i).

This means that, with the snprintf idea, we don't even have to set any
pm_domain_names list anymore, at all, and we can either reuse num_pm_domains
or just get the number of PDs limited by the binding - but that's a problem for
the future me/us I guess...

But since we're there...

Please, I'd like to hear your opinion about the core%d idea :-)

Anyway, I think that for now I'm choosing the "comment shortcut" for this patch.

P.S.: Thanks for the feedback!

Cheers,
Angelo

Steve

+ .pm_features = BIT(GPU_PM_CLK_DIS) | BIT(GPU_PM_VREG_OFF),
+};
+
static const char * const mediatek_mt8192_supplies[] = { "mali", NULL };
static const char * const mediatek_mt8192_pm_domains[] = { "core0", "core1", "core2",
"core3", "core4" };
@@ -808,6 +816,7 @@ static const struct of_device_id dt_match[] = {
{ .compatible = "mediatek,mt8183-mali", .data = &mediatek_mt8183_data },
{ .compatible = "mediatek,mt8183b-mali", .data = &mediatek_mt8183_b_data },
{ .compatible = "mediatek,mt8186-mali", .data = &mediatek_mt8186_data },
+ { .compatible = "mediatek,mt8188-mali", .data = &mediatek_mt8188_data },
{ .compatible = "mediatek,mt8192-mali", .data = &mediatek_mt8192_data },
{}
};