drm/bridge: dw-mipi-dsi.c: Add VPG runtime config through debugfs

Add support for the video pattern generator (VPG) BER pattern mode and
configuration in runtime.

This enables using the debugfs interface to manipulate the VPG after
the pipeline is set.
Also, enables the usage of the VPG BER pattern.

Changes in v2:
  - Added VID_MODE_VPG_MODE
  - Solved incompatible return type on __get and __set
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Adrian Pop <pop.adrian61@gmail.com>
Signed-off-by: Angelo Ribeiro <angelo.ribeiro@synopsys.com>
Tested-by: Yannick Fertre <yannick.fertre@st.com>
Tested-by: Adrian Pop <pop.adrian61@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Jose Abreu <jose.abreu@synopsys.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a809feb7d7153a92e323416f744f1565e995da01.1586180592.git.angelo.ribeiro@synopsys.com

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -91,6 +91,7 @@
 #define VID_MODE_TYPE_MASK			0x3
 #define ENABLE_LOW_POWER_CMD		BIT(15)
 #define VID_MODE_VPG_ENABLE		BIT(16)
+#define VID_MODE_VPG_MODE		BIT(20)
 #define VID_MODE_VPG_HORIZONTAL		BIT(24)
 
 #define DSI_VID_PKT_SIZE		0x3c
@@ -221,6 +222,21 @@
 #define PHY_STATUS_TIMEOUT_US		10000
 #define CMD_PKT_STATUS_TIMEOUT_US	20000
 
+#ifdef CONFIG_DEBUG_FS
+#define VPG_DEFS(name, dsi) \
+	((void __force *)&((*dsi).vpg_defs.name))
+
+#define REGISTER(name, mask, dsi) \
+	{ #name, VPG_DEFS(name, dsi), mask, dsi }
+
+struct debugfs_entries {
+	const char				*name;
+	bool					*reg;
+	u32					mask;
+	struct dw_mipi_dsi			*dsi;
+};
+#endif /* CONFIG_DEBUG_FS */
+
 struct dw_mipi_dsi {
 	struct drm_bridge bridge;
 	struct mipi_dsi_host dsi_host;
@@ -238,9 +254,12 @@ struct dw_mipi_dsi {
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs;
-
+	struct debugfs_entries *debugfs_vpg;
+	struct {
 		bool vpg;
 		bool vpg_horizontal;
+		bool vpg_ber_pattern;
+	} vpg_defs;
 #endif /* CONFIG_DEBUG_FS */
 
 	struct dw_mipi_dsi *master; /* dual-dsi master ptr */
@@ -545,9 +564,11 @@ static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
 		val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
 
 #ifdef CONFIG_DEBUG_FS
-	if (dsi->vpg) {
+	if (dsi->vpg_defs.vpg) {
 		val |= VID_MODE_VPG_ENABLE;
-		val |= dsi->vpg_horizontal ? VID_MODE_VPG_HORIZONTAL : 0;
+		val |= dsi->vpg_defs.vpg_horizontal ?
+		       VID_MODE_VPG_HORIZONTAL : 0;
+		val |= dsi->vpg_defs.vpg_ber_pattern ? VID_MODE_VPG_MODE : 0;
 	}
 #endif /* CONFIG_DEBUG_FS */
 
@@ -978,6 +999,68 @@ static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
 
 #ifdef CONFIG_DEBUG_FS
 
+int dw_mipi_dsi_debugfs_write(void *data, u64 val)
+{
+	struct debugfs_entries *vpg = data;
+	struct dw_mipi_dsi *dsi;
+	u32 mode_cfg;
+
+	if (!vpg)
+		return -ENODEV;
+
+	dsi = vpg->dsi;
+
+	*vpg->reg = (bool)val;
+
+	mode_cfg = dsi_read(dsi, DSI_VID_MODE_CFG);
+
+	if (*vpg->reg)
+		mode_cfg |= vpg->mask;
+	else
+		mode_cfg &= ~vpg->mask;
+
+	dsi_write(dsi, DSI_VID_MODE_CFG, mode_cfg);
+
+	return 0;
+}
+
+int dw_mipi_dsi_debugfs_show(void *data, u64 *val)
+{
+	struct debugfs_entries *vpg = data;
+
+	if (!vpg)
+		return -ENODEV;
+
+	*val = *vpg->reg;
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_mipi_dsi_debugfs_show,
+			 dw_mipi_dsi_debugfs_write, "%llu\n");
+
+static void debugfs_create_files(void *data)
+{
+	struct dw_mipi_dsi *dsi = data;
+	struct debugfs_entries debugfs[] = {
+		REGISTER(vpg, VID_MODE_VPG_ENABLE, dsi),
+		REGISTER(vpg_horizontal, VID_MODE_VPG_HORIZONTAL, dsi),
+		REGISTER(vpg_ber_pattern, VID_MODE_VPG_MODE, dsi),
+	};
+	int i;
+
+	dsi->debugfs_vpg = kmalloc(sizeof(debugfs), GFP_KERNEL);
+	if (!dsi->debugfs_vpg)
+		return;
+
+	memcpy(dsi->debugfs_vpg, debugfs, sizeof(debugfs));
+
+	for (i = 0; i < ARRAY_SIZE(debugfs); i++)
+		debugfs_create_file(dsi->debugfs_vpg[i].name, 0644,
+				    dsi->debugfs, &dsi->debugfs_vpg[i],
+				    &fops_x32);
+}
+
 static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
 {
 	dsi->debugfs = debugfs_create_dir(dev_name(dsi->dev), NULL);
@@ -986,14 +1069,13 @@ static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
 		return;
 	}
 
-	debugfs_create_bool("vpg", 0660, dsi->debugfs, &dsi->vpg);
-	debugfs_create_bool("vpg_horizontal", 0660, dsi->debugfs,
-			    &dsi->vpg_horizontal);
+	debugfs_create_files(dsi);
 }
 
 static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi)
 {
 	debugfs_remove_recursive(dsi->debugfs);
+	kfree(dsi->debugfs_vpg);
 }
 
 #else