drm: sti: remove useless fields from vtg structure

Drivers are registered on platform bus so the private list
could be replace by a call to of_find_device_by_node().
Changing this also makes dev, np and link fields useless
in vtg structure.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1510146255-24982-1-git-send-email-benjamin.gaignard@linaro.org

drivers/gpu/drm/sti/Kconfig

@@ -8,5 +8,6 @@ config DRM_STI
 	select DRM_PANEL
 	select FW_LOADER
 	select SND_SOC_HDMI_CODEC if SND_SOC
+	select OF
 	help
 	  Choose this option to enable DRM on STM stiH4xx chipset

drivers/gpu/drm/sti/sti_vtg.c

@@ -9,6 +9,7 @@
 
 #include <linux/module.h>
 #include <linux/notifier.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 
 #include <drm/drmP.h>
@@ -72,8 +73,6 @@
 #define AWG_DELAY_ED        (-8)
 #define AWG_DELAY_SD        (-7)
 
-static LIST_HEAD(vtg_lookup);
-
 /*
  * STI VTG register offset structure
  *
@@ -123,42 +122,31 @@ struct sti_vtg_sync_params {
 /**
  * STI VTG structure
  *
- * @dev: pointer to device driver
- * @np: device node
  * @regs: register mapping
  * @sync_params: synchronisation parameters used to generate timings
  * @irq: VTG irq
  * @irq_status: store the IRQ status value
  * @notifier_list: notifier callback
  * @crtc: the CRTC for vblank event
- * @link: List node to link the structure in lookup list
  */
 struct sti_vtg {
-	struct device *dev;
-	struct device_node *np;
 	void __iomem *regs;
 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
 	int irq;
 	u32 irq_status;
 	struct raw_notifier_head notifier_list;
 	struct drm_crtc *crtc;
-	struct list_head link;
 };
 
-static void vtg_register(struct sti_vtg *vtg)
-{
-	list_add_tail(&vtg->link, &vtg_lookup);
-}
-
 struct sti_vtg *of_vtg_find(struct device_node *np)
 {
-	struct sti_vtg *vtg;
+	struct platform_device *pdev;
 
-	list_for_each_entry(vtg, &vtg_lookup, link) {
-		if (vtg->np == np)
-			return vtg;
-	}
-	return NULL;
+	pdev = of_find_device_by_node(np);
+	if (!pdev)
+		return NULL;
+
+	return (struct sti_vtg *)platform_get_drvdata(pdev);
 }
 
 static void vtg_reset(struct sti_vtg *vtg)
@@ -397,9 +385,6 @@ static int vtg_probe(struct platform_device *pdev)
 	if (!vtg)
 		return -ENOMEM;
 
-	vtg->dev = dev;
-	vtg->np = pdev->dev.of_node;
-
 	/* Get Memory ressources */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
@@ -428,10 +413,9 @@ static int vtg_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	vtg_register(vtg);
 	platform_set_drvdata(pdev, vtg);
 
-	DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
+	DRM_INFO("%s %s\n", __func__, dev_name(dev));
 
 	return 0;
 }