Hi Philipp,

Thank you to take a look

On 20/7/21 12:52, Philipp Zabel wrote:

Hi Enric,

On Wed, 2021-07-14 at 12:11 +0200, Enric Balletbo i Serra wrote:

quoted

Among other features the mmsys driver should implement a reset
controller to be able to reset different bits from their space.

Cc: Jitao Shi <redacted>
Suggested-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Enric Balletbo i Serra <redacted>

The reset controller driver looks fine, just two questions below.

quoted

---

(no changes since v1)

 drivers/soc/mediatek/mtk-mmsys.c | 69 ++++++++++++++++++++++++++++++++
 drivers/soc/mediatek/mtk-mmsys.h |  2 +
 2 files changed, 71 insertions(+)

diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
index e681029fe804..6ac4deff0164 100644
--- a/drivers/soc/mediatek/mtk-mmsys.c
+++ b/drivers/soc/mediatek/mtk-mmsys.c

[...]

quoted

@@ -91,6 +95,59 @@ void mtk_mmsys_ddp_disconnect(struct device *dev,

[...]

quoted

+static int mtk_mmsys_reset(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	int ret;
+
+	ret = mtk_mmsys_reset_assert(rcdev, id);
+	if (ret)
+		return ret;
+
+	usleep_range(1000, 1100);

Is this known to be enough for all IP cores that can be reset by this
controller?

This time is copied from the downstream kernel, so, tbh, I am not totally sure
is enough or needed. Let me try to reach the Mediatek people for if they can
answer this.

quoted

+	return mtk_mmsys_reset_deassert(rcdev, id);
+}
+
+static const struct reset_control_ops mtk_mmsys_reset_ops = {
+	.assert = mtk_mmsys_reset_assert,
+	.deassert = mtk_mmsys_reset_deassert,
+	.reset = mtk_mmsys_reset,
+};
+
 static int mtk_mmsys_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -111,6 +168,18 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	spin_lock_init(&mmsys->lock);
+
+	mmsys->rcdev.owner = THIS_MODULE;
+	mmsys->rcdev.nr_resets = 32;

Are all bits in the MMSYS_SW0_RST_B register individual reset controls?

Yes, all are individual reset controls, mostly related to display but not all
(i.e dsi, dpi ...)

Thanks,
  Enric

regards
Philipp

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