[RFC PATCH 05/10] drm/msm/dsi: implement manual power control

Dmitry Baryshkov
2023-10-16T16:57:32Z

Implement new API for tight control over the DSI link's power state.
This allows bridge and panel drivers to send DSI commands at a proper
time.

Note, this also brings back the ps8640 workaround (to be removed later,
once ps8640 driver sets up the MIPI_DSI_MANUAL_POWERUP flag).. We have
to make sure that the DSI link stays disabled in case of this bridge,
otherwise it will not work.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/gpu/drm/msm/dsi/dsi.h | 4 ++
drivers/gpu/drm/msm/dsi/dsi_host.c | 44 +++++++++++++++++
drivers/gpu/drm/msm/dsi/dsi_manager.c | 68 +++++++++++++++++++++++----
3 files changed, 106 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
index a01c326774a6..e0ae2cb144de 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.h
@@ -63,6 +63,8 @@ bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len);
int msm_dsi_manager_register(struct msm_dsi *msm_dsi);
void msm_dsi_manager_unregister(struct msm_dsi *msm_dsi);
void msm_dsi_manager_tpg_enable(void);
+int msm_dsi_manager_power_up(int id);
+void msm_dsi_manager_power_down(int id);

/* msm dsi */
static inline bool msm_dsi_device_connected(struct msm_dsi *msm_dsi)
@@ -108,6 +110,8 @@ void msm_dsi_host_get_phy_clk_req(struct mipi_dsi_host *host,
void msm_dsi_host_destroy(struct mipi_dsi_host *host);
int msm_dsi_host_modeset_init(struct mipi_dsi_host *host,
struct drm_device *dev);
+bool msm_dsi_host_auto_powerup(struct mipi_dsi_host *host);
+bool msm_dsi_host_early_powerup(struct mipi_dsi_host *host);
int msm_dsi_host_init(struct msm_dsi *msm_dsi);
int msm_dsi_runtime_suspend(struct device *dev);
int msm_dsi_runtime_resume(struct device *dev);
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index fd2201cb62db..7010a6f17c5f 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1671,10 +1671,54 @@ static ssize_t dsi_host_transfer(struct mipi_dsi_host *host,
return ret;
}

+static bool msm_dsi_host_manual_powerup(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ return msm_host->mode_flags & MIPI_DSI_MANUAL_POWERUP;
+}
+
+bool msm_dsi_host_auto_powerup(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ return msm_host->mode_flags & MIPI_DSI_AUTO_POWERUP;
+}
+
+bool msm_dsi_host_early_powerup(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ return !msm_dsi_host_manual_powerup(host) &&
+ !msm_dsi_host_auto_powerup(host);
+}
+
+static int msm_dsi_host_power_up(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ if (msm_dsi_host_auto_powerup(host))
+ return 0;
+
+ return msm_dsi_manager_power_up(msm_host->id);
+}
+
+static void msm_dsi_host_power_down(struct mipi_dsi_host *host)
+{
+ struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+ if (!msm_dsi_host_manual_powerup(host))
+ return;
+
+ msm_dsi_manager_power_down(msm_host->id);
+}
+
static const struct mipi_dsi_host_ops dsi_host_ops = {
.attach = dsi_host_attach,
.detach = dsi_host_detach,
.transfer = dsi_host_transfer,
+ .power_up = msm_dsi_host_power_up,
+ .power_down = msm_dsi_host_power_down,
};

/*
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index 9fa1f29ec11a..2d7040d21239 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -198,6 +198,44 @@ static int dsi_mgr_bridge_get_id(struct drm_bridge *bridge)
return dsi_bridge->id;
}

+/*
+ * If the next bridge in the chain is the Parade ps8640 bridge chip then don't
+ * power on early since it seems to violate the expectations of the firmware
+ * that the bridge chip is running.
+ */
+static bool dsi_mgr_next_is_ps8640(struct drm_bridge *bridge)
+{
+ struct drm_bridge *next_bridge = drm_bridge_get_next_bridge(bridge);
+
+ return next_bridge &&
+ next_bridge->of_node &&
+ of_device_is_compatible(next_bridge->of_node, "parade,ps8640");
+}
+
+static bool dsi_mgr_auto_powerup(struct drm_bridge *bridge)
+{
+ int id = dsi_mgr_bridge_get_id(bridge);
+ struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+ struct mipi_dsi_host *host = msm_dsi->host;
+
+ if (dsi_mgr_next_is_ps8640(bridge))
+ return true;
+
+ return msm_dsi_host_auto_powerup(host);
+}
+
+static bool dsi_mgr_early_powerup(struct drm_bridge *bridge)
+{
+ int id = dsi_mgr_bridge_get_id(bridge);
+ struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+ struct mipi_dsi_host *host = msm_dsi->host;
+
+ if (dsi_mgr_next_is_ps8640(bridge))
+ return false;
+
+ return msm_dsi_host_early_powerup(host);
+}
+
static void msm_dsi_manager_set_split_display(u8 id)
{
struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
@@ -228,9 +266,8 @@ static void msm_dsi_manager_set_split_display(u8 id)
}
}

-static int dsi_mgr_bridge_power_on(struct drm_bridge *bridge)
+int msm_dsi_manager_power_up(int id)
{
- int id = dsi_mgr_bridge_get_id(bridge);
struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
struct mipi_dsi_host *host = msm_dsi->host;
@@ -240,6 +277,10 @@ static int dsi_mgr_bridge_power_on(struct drm_bridge *bridge)

DBG("id=%d", id);

+ /* Do nothing with the host if it is slave-DSI in case of bonded DSI */
+ if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id))
+ return 0;
+
ret = dsi_mgr_phy_enable(id, phy_shared_timings);
if (ret)
goto phy_en_fail;
@@ -278,9 +319,8 @@ static int dsi_mgr_bridge_power_on(struct drm_bridge *bridge)
return ret;
}

-static void dsi_mgr_bridge_power_off(struct drm_bridge *bridge)
+void msm_dsi_manager_power_down(int id)
{
- int id = dsi_mgr_bridge_get_id(bridge);
struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
struct mipi_dsi_host *host = msm_dsi->host;
@@ -312,10 +352,12 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id))
return;

- ret = dsi_mgr_bridge_power_on(bridge);
- if (ret) {
- dev_err(&msm_dsi->pdev->dev, "Power on failed: %d\n", ret);
- return;
+ if (dsi_mgr_auto_powerup(bridge)) {
+ ret = msm_dsi_manager_power_up(id);
+ if (ret) {
+ dev_err(&msm_dsi->pdev->dev, "Power on failed: %d\n", ret);
+ return;
+ }
}

ret = msm_dsi_host_enable(host);
@@ -337,7 +379,8 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
host1_en_fail:
msm_dsi_host_disable(host);
host_en_fail:
- dsi_mgr_bridge_power_off(bridge);
+ if (dsi_mgr_auto_powerup(bridge))
+ msm_dsi_manager_power_down(id);
}

void msm_dsi_manager_tpg_enable(void)
@@ -390,7 +433,9 @@ static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
/* Save PHY status if it is a clock source */
msm_dsi_phy_pll_save_state(msm_dsi->phy);

- dsi_mgr_bridge_power_off(bridge);
+ if (dsi_mgr_auto_powerup(bridge) ||
+ dsi_mgr_early_powerup(bridge))
+ msm_dsi_manager_power_down(id);
}

static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
@@ -411,6 +456,9 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
msm_dsi_host_set_display_mode(host, adjusted_mode);
if (is_bonded_dsi && other_dsi)
msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode);
+
+ if (dsi_mgr_early_powerup(bridge))
+ msm_dsi_manager_power_up(id);
}

static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *bridge,
--
2.42.0