OMAPDSS: remove omap_dss_start/stop_device()

The omap_dss_start_device() and omap_dss_stop_device(), called by the
DSS output drivers, are old relics. They originally did something
totally else, but nowadays they increase the module ref count for panels
that are enabled.

This model is quite broken: the panel modules may be used even before
they are enabled. For example, configuring the panel requires calls to
functions located in the panel modules.

In the following patches we try to improve the ref count management for
the modules and display devices. The first step, however, is to remove
the omap_dss_start/stop_device() totally.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/display.c

@@ -233,26 +233,6 @@ struct omap_dss_device *omap_dss_find_device(void *data,
 }
 EXPORT_SYMBOL(omap_dss_find_device);
 
-int omap_dss_start_device(struct omap_dss_device *dssdev)
-{
-	if (!dssdev->driver) {
-		DSSDBG("no driver\n");
-		return -ENODEV;
-	}
-
-	if (!try_module_get(dssdev->dev->driver->owner))
-		return -ENODEV;
-
-	return 0;
-}
-EXPORT_SYMBOL(omap_dss_start_device);
-
-void omap_dss_stop_device(struct omap_dss_device *dssdev)
-{
-	module_put(dssdev->dev->driver->owner);
-}
-EXPORT_SYMBOL(omap_dss_stop_device);
-
 void videomode_to_omap_video_timings(const struct videomode *vm,
 		struct omap_video_timings *ovt)
 {

drivers/video/omap2/dss/dpi.c

@@ -364,12 +364,6 @@ int omapdss_dpi_display_enable(struct omap_dss_device *dssdev)
 		goto err_no_out_mgr;
 	}
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err_start_dev;
-	}
-
 	if (dss_has_feature(FEAT_DPI_USES_VDDS_DSI)) {
 		r = regulator_enable(dpi.vdds_dsi_reg);
 		if (r)
@@ -424,8 +418,6 @@ int omapdss_dpi_display_enable(struct omap_dss_device *dssdev)
 	if (dss_has_feature(FEAT_DPI_USES_VDDS_DSI))
 		regulator_disable(dpi.vdds_dsi_reg);
 err_reg_enable:
-	omap_dss_stop_device(dssdev);
-err_start_dev:
 err_no_out_mgr:
 err_no_reg:
 	mutex_unlock(&dpi.lock);
@@ -452,8 +444,6 @@ void omapdss_dpi_display_disable(struct omap_dss_device *dssdev)
 	if (dss_has_feature(FEAT_DPI_USES_VDDS_DSI))
 		regulator_disable(dpi.vdds_dsi_reg);
 
-	omap_dss_stop_device(dssdev);
-
 	mutex_unlock(&dpi.lock);
 }
 EXPORT_SYMBOL(omapdss_dpi_display_disable);

drivers/video/omap2/dss/dsi.c

@@ -4592,12 +4592,6 @@ int omapdss_dsi_display_enable(struct omap_dss_device *dssdev)
 
 	mutex_lock(&dsi->lock);
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err_start_dev;
-	}
-
 	r = dsi_runtime_get(dsidev);
 	if (r)
 		goto err_get_dsi;
@@ -4618,8 +4612,6 @@ int omapdss_dsi_display_enable(struct omap_dss_device *dssdev)
 	dsi_enable_pll_clock(dsidev, 0);
 	dsi_runtime_put(dsidev);
 err_get_dsi:
-	omap_dss_stop_device(dssdev);
-err_start_dev:
 	mutex_unlock(&dsi->lock);
 	DSSDBG("dsi_display_enable FAILED\n");
 	return r;
@@ -4648,8 +4640,6 @@ void omapdss_dsi_display_disable(struct omap_dss_device *dssdev,
 	dsi_runtime_put(dsidev);
 	dsi_enable_pll_clock(dsidev, 0);
 
-	omap_dss_stop_device(dssdev);
-
 	mutex_unlock(&dsi->lock);
 }
 EXPORT_SYMBOL(omapdss_dsi_display_disable);

drivers/video/omap2/dss/hdmi.c

@@ -735,23 +735,15 @@ int omapdss_hdmi_display_enable(struct omap_dss_device *dssdev)
 
 	hdmi.ip_data.hpd_gpio = hdmi.hpd_gpio;
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err0;
-	}
-
 	r = hdmi_power_on_full(dssdev);
 	if (r) {
 		DSSERR("failed to power on device\n");
-		goto err1;
+		goto err0;
 	}
 
 	mutex_unlock(&hdmi.lock);
 	return 0;
 
-err1:
-	omap_dss_stop_device(dssdev);
 err0:
 	mutex_unlock(&hdmi.lock);
 	return r;
@@ -765,8 +757,6 @@ void omapdss_hdmi_display_disable(struct omap_dss_device *dssdev)
 
 	hdmi_power_off_full(dssdev);
 
-	omap_dss_stop_device(dssdev);
-
 	mutex_unlock(&hdmi.lock);
 }
 

drivers/video/omap2/dss/rfbi.c

@@ -902,12 +902,6 @@ int omapdss_rfbi_display_enable(struct omap_dss_device *dssdev)
 	if (r)
 		return r;
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err0;
-	}
-
 	r = dss_mgr_register_framedone_handler(out->manager,
 			framedone_callback, NULL);
 	if (r) {
@@ -924,8 +918,6 @@ int omapdss_rfbi_display_enable(struct omap_dss_device *dssdev)
 
 	return 0;
 err1:
-	omap_dss_stop_device(dssdev);
-err0:
 	rfbi_runtime_put();
 	return r;
 }
@@ -937,7 +929,6 @@ void omapdss_rfbi_display_disable(struct omap_dss_device *dssdev)
 
 	dss_mgr_unregister_framedone_handler(out->manager,
 			framedone_callback, NULL);
-	omap_dss_stop_device(dssdev);
 
 	rfbi_runtime_put();
 }

drivers/video/omap2/dss/sdi.c

@@ -138,12 +138,6 @@ int omapdss_sdi_display_enable(struct omap_dss_device *dssdev)
 		return -ENODEV;
 	}
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err_start_dev;
-	}
-
 	r = regulator_enable(sdi.vdds_sdi_reg);
 	if (r)
 		goto err_reg_enable;
@@ -215,8 +209,6 @@ int omapdss_sdi_display_enable(struct omap_dss_device *dssdev)
 err_get_dispc:
 	regulator_disable(sdi.vdds_sdi_reg);
 err_reg_enable:
-	omap_dss_stop_device(dssdev);
-err_start_dev:
 	return r;
 }
 EXPORT_SYMBOL(omapdss_sdi_display_enable);
@@ -232,8 +224,6 @@ void omapdss_sdi_display_disable(struct omap_dss_device *dssdev)
 	dispc_runtime_put();
 
 	regulator_disable(sdi.vdds_sdi_reg);
-
-	omap_dss_stop_device(dssdev);
 }
 EXPORT_SYMBOL(omapdss_sdi_display_disable);
 

drivers/video/omap2/dss/venc.c

@@ -513,23 +513,15 @@ int omapdss_venc_display_enable(struct omap_dss_device *dssdev)
 		goto err0;
 	}
 
-	r = omap_dss_start_device(dssdev);
-	if (r) {
-		DSSERR("failed to start device\n");
-		goto err0;
-	}
-
 	r = venc_power_on(dssdev);
 	if (r)
-		goto err1;
+		goto err0;
 
 	venc.wss_data = 0;
 
 	mutex_unlock(&venc.venc_lock);
 
 	return 0;
-err1:
-	omap_dss_stop_device(dssdev);
 err0:
 	mutex_unlock(&venc.venc_lock);
 	return r;
@@ -543,8 +535,6 @@ void omapdss_venc_display_disable(struct omap_dss_device *dssdev)
 
 	venc_power_off(dssdev);
 
-	omap_dss_stop_device(dssdev);
-
 	mutex_unlock(&venc.venc_lock);
 }
 

include/video/omapdss.h

@@ -779,9 +779,6 @@ struct omap_dss_device *omap_dss_find_device(void *data,
 		int (*match)(struct omap_dss_device *dssdev, void *data));
 const char *omapdss_get_default_display_name(void);
 
-int omap_dss_start_device(struct omap_dss_device *dssdev);
-void omap_dss_stop_device(struct omap_dss_device *dssdev);
-
 void videomode_to_omap_video_timings(const struct videomode *vm,
 		struct omap_video_timings *ovt);
 void omap_video_timings_to_videomode(const struct omap_video_timings *ovt,