[PATCH 5/6] drm/vc4: dsi: Convert to using a bridge instead of encoder

From: Maxime Ripard
Date: Wed Dec 07 2022 - 05:28:07 EST


From: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>

Remove the encoder functions, and create a bridge attached to
this dumb encoder which implements the same functionality.

As a bridge has state which an encoder doesn't, we need to
add the state management functions as well.

As there is no bridge atomic_mode_set, move the initialisation
code that was in mode_set into _pre_enable.
The code to actually enable and disable sending video are split
from the general control into _enable and _disable.

Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_dsi.c | 121 +++++++++++++++++++++++++++++++-----------
1 file changed, 90 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index b90186f38749..a7b8ffd995b0 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -557,6 +557,7 @@ struct vc4_dsi {
struct platform_device *pdev;

struct drm_bridge *out_bridge;
+ struct drm_bridge bridge;

void __iomem *regs;

@@ -608,6 +609,12 @@ to_vc4_dsi(struct drm_encoder *encoder)
return container_of(encoder, struct vc4_dsi, encoder.base);
}

+static inline struct vc4_dsi *
+bridge_to_vc4_dsi(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct vc4_dsi, bridge);
+}
+
static inline void
dsi_dma_workaround_write(struct vc4_dsi *dsi, u32 offset, u32 val)
{
@@ -789,10 +796,21 @@ dsi_esc_timing(u32 ns)
return DIV_ROUND_UP(ns, ESC_TIME_NS);
}

-static void vc4_dsi_encoder_disable(struct drm_encoder *encoder,
- struct drm_atomic_state *state)
+static void vc4_dsi_bridge_disable(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
{
- struct vc4_dsi *dsi = to_vc4_dsi(encoder);
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+ u32 disp0_ctrl;
+
+ disp0_ctrl = DSI_PORT_READ(DISP0_CTRL);
+ disp0_ctrl &= ~DSI_DISP0_ENABLE;
+ DSI_PORT_WRITE(DISP0_CTRL, disp0_ctrl);
+}
+
+static void vc4_dsi_bridge_post_disable(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
struct device *dev = &dsi->pdev->dev;

vc4_dsi_ulps(dsi, true);
@@ -817,11 +835,11 @@ static void vc4_dsi_encoder_disable(struct drm_encoder *encoder,
* higher-than-expected clock rate to the panel, but that's what the
* firmware does too.
*/
-static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
- const struct drm_display_mode *mode,
- struct drm_display_mode *adjusted_mode)
+static bool vc4_dsi_bridge_mode_fixup(struct drm_bridge *bridge,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
{
- struct vc4_dsi *dsi = to_vc4_dsi(encoder);
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
struct clk *phy_parent = clk_get_parent(dsi->pll_phy_clock);
unsigned long parent_rate = clk_get_rate(phy_parent);
unsigned long pixel_clock_hz = mode->clock * 1000;
@@ -853,15 +871,18 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
return true;
}

-static void vc4_dsi_encoder_mode_set(struct drm_encoder *encoder,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state)
+static void vc4_dsi_bridge_pre_enable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_state)
{
- struct vc4_dsi *dsi = to_vc4_dsi(encoder);
+ struct drm_atomic_state *state = old_state->base.state;
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+ const struct drm_crtc_state *crtc_state;
struct device *dev = &dsi->pdev->dev;
const struct drm_display_mode *mode;
+ struct drm_connector *connector;
bool debug_dump_regs = false;
unsigned long hs_clock;
+ struct drm_crtc *crtc;
u32 ui_ns;
/* Minimum LP state duration in escape clock cycles. */
u32 lpx = dsi_esc_timing(60);
@@ -882,6 +903,14 @@ static void vc4_dsi_encoder_mode_set(struct drm_encoder *encoder,
drm_print_regset32(&p, &dsi->regset);
}

+ /*
+ * Retrieve the CRTC adjusted mode. This requires a little dance to go
+ * from the bridge to the encoder, to the connector and to the CRTC.
+ */
+ connector = drm_atomic_get_new_connector_for_encoder(state,
+ bridge->encoder);
+ crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
+ crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
mode = &crtc_state->adjusted_mode;

pixel_clock_hz = mode->clock * 1000;
@@ -1096,13 +1125,6 @@ static void vc4_dsi_encoder_mode_set(struct drm_encoder *encoder,
~DSI_PORT_BIT(PHY_AFEC0_RESET));

vc4_dsi_ulps(dsi, false);
-}
-
-static void vc4_dsi_encoder_enable(struct drm_encoder *encoder,
- struct drm_atomic_state *state)
-{
- struct vc4_dsi *dsi = to_vc4_dsi(encoder);
- bool debug_dump_regs = false;

if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
DSI_PORT_WRITE(DISP0_CTRL,
@@ -1111,13 +1133,23 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder,
VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
DSI_DISP0_LP_STOP_CTRL) |
- DSI_DISP0_ST_END |
- DSI_DISP0_ENABLE);
+ DSI_DISP0_ST_END);
} else {
DSI_PORT_WRITE(DISP0_CTRL,
- DSI_DISP0_COMMAND_MODE |
- DSI_DISP0_ENABLE);
+ DSI_DISP0_COMMAND_MODE);
}
+}
+
+static void vc4_dsi_bridge_enable(struct drm_bridge *bridge,
+ struct drm_bridge_state *old_state)
+{
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+ bool debug_dump_regs = false;
+ u32 disp0_ctrl;
+
+ disp0_ctrl = DSI_PORT_READ(DISP0_CTRL);
+ disp0_ctrl |= DSI_DISP0_ENABLE;
+ DSI_PORT_WRITE(DISP0_CTRL, disp0_ctrl);

if (debug_dump_regs) {
struct drm_printer p = drm_info_printer(&dsi->pdev->dev);
@@ -1126,6 +1158,16 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder,
}
}

+static int vc4_dsi_bridge_attach(struct drm_bridge *bridge,
+ enum drm_bridge_attach_flags flags)
+{
+ struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+
+ /* Attach the panel or bridge to the dsi bridge */
+ return drm_bridge_attach(bridge->encoder, dsi->out_bridge,
+ &dsi->bridge, flags);
+}
+
static ssize_t vc4_dsi_host_transfer(struct mipi_dsi_host *host,
const struct mipi_dsi_msg *msg)
{
@@ -1302,6 +1344,7 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
struct mipi_dsi_device *device)
{
struct vc4_dsi *dsi = host_to_dsi(host);
+ int ret;

dsi->lanes = device->lanes;
dsi->channel = device->channel;
@@ -1336,7 +1379,15 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
return 0;
}

- return component_add(&dsi->pdev->dev, &vc4_dsi_ops);
+ drm_bridge_add(&dsi->bridge);
+
+ ret = component_add(&dsi->pdev->dev, &vc4_dsi_ops);
+ if (ret) {
+ drm_bridge_remove(&dsi->bridge);
+ return ret;
+ }
+
+ return 0;
}

static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
@@ -1345,6 +1396,7 @@ static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
struct vc4_dsi *dsi = host_to_dsi(host);

component_del(&dsi->pdev->dev, &vc4_dsi_ops);
+ drm_bridge_remove(&dsi->bridge);
return 0;
}

@@ -1354,11 +1406,16 @@ static const struct mipi_dsi_host_ops vc4_dsi_host_ops = {
.transfer = vc4_dsi_host_transfer,
};

-static const struct drm_encoder_helper_funcs vc4_dsi_encoder_helper_funcs = {
- .atomic_disable = vc4_dsi_encoder_disable,
- .atomic_enable = vc4_dsi_encoder_enable,
- .mode_fixup = vc4_dsi_encoder_mode_fixup,
- .atomic_mode_set = vc4_dsi_encoder_mode_set,
+static const struct drm_bridge_funcs vc4_dsi_bridge_funcs = {
+ .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+ .atomic_reset = drm_atomic_helper_bridge_reset,
+ .atomic_pre_enable = vc4_dsi_bridge_pre_enable,
+ .atomic_enable = vc4_dsi_bridge_enable,
+ .atomic_disable = vc4_dsi_bridge_disable,
+ .atomic_post_disable = vc4_dsi_bridge_post_disable,
+ .attach = vc4_dsi_bridge_attach,
+ .mode_fixup = vc4_dsi_bridge_mode_fixup,
};

static int vc4_dsi_late_register(struct drm_encoder *encoder)
@@ -1733,13 +1790,11 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
if (ret)
return ret;

- drm_encoder_helper_add(encoder, &vc4_dsi_encoder_helper_funcs);
-
ret = devm_pm_runtime_enable(dev);
if (ret)
return ret;

- ret = drm_bridge_attach(encoder, dsi->out_bridge, NULL, 0);
+ ret = drm_bridge_attach(encoder, &dsi->bridge, NULL, 0);
if (ret)
return ret;

@@ -1761,7 +1816,11 @@ static int vc4_dsi_dev_probe(struct platform_device *pdev)
dev_set_drvdata(dev, dsi);

kref_init(&dsi->kref);
+
dsi->pdev = pdev;
+ dsi->bridge.funcs = &vc4_dsi_bridge_funcs;
+ dsi->bridge.of_node = dev->of_node;
+ dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
dsi->dsi_host.ops = &vc4_dsi_host_ops;
dsi->dsi_host.dev = dev;
mipi_dsi_host_register(&dsi->dsi_host);

--
2.38.1