[PATCH 5.19 0338/1157] drm/mediatek: Separate poweron/poweroff from enable/disable and define new funcs

Greg Kroah-Hartman
2022-08-15T23:28:21Z

From: Jitao Shi <jitao.shi@mediatek.com>

[ Upstream commit cde7e2e35c2866d22a3a012e72a41052dfcc255d ]

In order to match the changes of "Use the drm_panel_bridge API",
the poweron/poweroff of dsi is extracted from enable/disable and
defined as new funcs (atomic_pre_enable/atomic_post_disable).

Since dsi_poweron is moved from dsi_enable to pre_enable function, in
order to avoid poweron failure, the operation of dsi register fails to
cause bus hang. Therefore, the protection mechanism is added to the
dsi_enable function.

Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the drm_panel_bridge API")

Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1653012007-11854-3-git-send-email-xinlei.lee@mediatek.com/
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/mediatek/mtk_dsi.c | 53 +++++++++++++++++++-----------
1 file changed, 34 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 6e7793f935da..966a4729bb41 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -691,16 +691,6 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
if (--dsi->refcount != 0)
return;

- /*
- * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
- * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
- * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
- * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
- * after dsi is fully set.
- */
- mtk_dsi_stop(dsi);
-
- mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
mtk_dsi_reset_engine(dsi);
mtk_dsi_lane0_ulp_mode_enter(dsi);
mtk_dsi_clk_ulp_mode_enter(dsi);
@@ -715,17 +705,9 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)

static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
{
- int ret;
-
if (dsi->enabled)
return;

- ret = mtk_dsi_poweron(dsi);
- if (ret < 0) {
- DRM_ERROR("failed to power on dsi\n");
- return;
- }
-
mtk_dsi_set_mode(dsi);
mtk_dsi_clk_hs_mode(dsi, 1);

@@ -739,7 +721,16 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
if (!dsi->enabled)
return;

- mtk_dsi_poweroff(dsi);
+ /*
+ * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
+ * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
+ * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
+ * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
+ * after dsi is fully set.
+ */
+ mtk_dsi_stop(dsi);
+
+ mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);

dsi->enabled = false;
}
@@ -776,13 +767,37 @@ static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
{
struct mtk_dsi *dsi = bridge_to_dsi(bridge);

+ if (dsi->refcount == 0)
+ return;
+
mtk_output_dsi_enable(dsi);
}

+static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_bridge_state)
+{
+ struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+ int ret;
+
+ ret = mtk_dsi_poweron(dsi);
+ if (ret < 0)
+ DRM_ERROR("failed to power on dsi\n");
+}
+
+static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_bridge_state)
+{
+ struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+
+ mtk_dsi_poweroff(dsi);
+}
+
static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
.attach = mtk_dsi_bridge_attach,
.atomic_disable = mtk_dsi_bridge_atomic_disable,
.atomic_enable = mtk_dsi_bridge_atomic_enable,
+ .atomic_pre_enable = mtk_dsi_bridge_atomic_pre_enable,
+ .atomic_post_disable = mtk_dsi_bridge_atomic_post_disable,
.mode_set = mtk_dsi_bridge_mode_set,
};

--
2.35.1