mipi-dsi: rpi: use backlight device to control pwm of mcu.

 After applying this commit, suspend/resume process will disabling/enabling backlight.

Change-Id: I4b6170b23c246af2cab11c456447bf1bea8ecf1a

Author: singhomelee

drivers/gpu/drm/panel/panel-asus-ili9881c.c

@@ -597,26 +597,25 @@ static int ili9881c_enable(struct drm_panel *panel)
 	msleep(120);
 
 	//backlight_enable(ctx->backlight);
-
-#if 0
-	if (!powering_on) {
-		tinker_mcu_ili9881c_set_bright(0x9f);
-		msleep(10);
-		powering_on = 1;
-	}
-
-	tinker_mcu_ili9881c_set_bright(0x9f);
-#else
-	ctx->backlight->props.power = FB_BLANK_UNBLANK;
-	if (!powering_on) {
-		ctx->backlight->props.brightness = 50;
+	if (ctx->backlight) {
+		ctx->backlight->props.power = FB_BLANK_UNBLANK;
+		if (!powering_on) {
+			ctx->backlight->props.brightness = 50;
+			backlight_update_status(ctx->backlight);
+			msleep(10);
+			powering_on = 1;
+			ctx->backlight->props.brightness = 255;
+		}
 		backlight_update_status(ctx->backlight);
-		msleep(10);
-		powering_on = 1;
-		ctx->backlight->props.brightness = 255;
+	} else {
+		if (!powering_on) {
+			tinker_mcu_ili9881c_set_bright(0x1A);
+			msleep(10);
+			powering_on = 1;
+		}
+		tinker_mcu_ili9881c_set_bright(0x1F);
 	}
-	backlight_update_status(ctx->backlight);
-#endif
+
 
 	enable = 1;
 
@@ -630,9 +629,13 @@ static int ili9881c_disable(struct drm_panel *panel)
 	enable = 0;
 	pr_info("%s\n", __func__);
 	//backlight_disable(ctx->backlight);
-	//tinker_mcu_ili9881c_set_bright(0x00);
-	ctx->backlight->props.power = FB_BLANK_POWERDOWN;
-	backlight_update_status(ctx->backlight);
+
+	if (ctx->backlight) {
+		ctx->backlight->props.power = FB_BLANK_POWERDOWN;
+		backlight_update_status(ctx->backlight);
+	} else {
+		tinker_mcu_ili9881c_set_bright(0x00);
+	}
 
 	return 0;
 }
@@ -747,9 +750,16 @@ int ili9881c_dsi_probe(struct mipi_dsi_device *dsi)
 	ctx->backlight = tinker_mcu_ili9881c_get_backlightdev();
 	if (!ctx->backlight) {
 		printk("ili9881c_dsi_probe get backlight fail\n");
-		return -ENODEV;
+		//return -ENODEV;
+		/* avoid  if there is no mipi-panel case, dw_mipi_dsi_bind() will return EPROBE_DEFER
+		                            to trigger deferred_probe_work_func() continue init panel driver
+		                            untile panel init  successful.
+		                            SO, we CAN NOT return  error.
+		*/
+	} else {
+		printk("t ili9881c_dsi_probe get backligh device successful\n");
+		ctx->backlight->props.brightness = 255;
 	}
-	ctx->backlight->props.brightness = 255;
 
 	ctx->dsi = dsi;
 	drm_panel_init(&ctx->panel);

drivers/miniarm/dsi/panel-toshiba-tc358762.c

@@ -194,11 +194,12 @@ static int tc358762_disable(struct drm_panel *panel)
 
 	printk("panel disable\n");
 
-	tinker_mcu_set_bright(0x00);
-
 	if (p->backlight) {
 		p->backlight->props.power = FB_BLANK_POWERDOWN;
 		backlight_update_status(p->backlight);
+	} else {
+		printk("panel disable: no backlight device\n");
+		tinker_mcu_set_bright(0x00);
 	}
 
 	if (p->desc && p->desc->delay.disable)
@@ -295,6 +296,7 @@ static int tc358762_prepare(struct drm_panel *panel)
 	return 0;
 }
 
+extern struct backlight_device * tinker_mcu_get_backlightdev(void);
 extern void tinker_mcu_screen_power_up(void);
 extern void tinker_ft5406_start_polling(void);
 static int tc358762_enable(struct drm_panel *panel)
@@ -322,10 +324,11 @@ static int tc358762_enable(struct drm_panel *panel)
 	if (p->backlight) {
 		p->backlight->props.power = FB_BLANK_UNBLANK;
 		backlight_update_status(p->backlight);
+	} else {
+		printk("panel enable: no backlight device\n");
+		tinker_mcu_set_bright(0xFF);
 	}
 
-	tinker_mcu_set_bright(0xFF);
-
 	p->enabled = true;
 
 	return 0;
@@ -420,6 +423,15 @@ static int tc358762_mipi_probe(struct mipi_dsi_device *dsi, const struct panel_d
 
 		if (!panel->backlight)
 			return -EPROBE_DEFER;
+	} else {
+		panel->backlight =  tinker_mcu_get_backlightdev();
+		if (!panel->backlight) {
+			printk("tc358762_mipi_probe get backlight fail\n");
+			//return -ENODEV;
+		} else {
+			panel->backlight->props.brightness = 255;
+			printk("tc358762_mipi_probe get backligh device successful\n");
+		}
 	}
 
 	ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
@@ -567,6 +579,7 @@ int tc358762_dsi_probe(struct mipi_dsi_device *dsi)
 
 	if (!of_property_read_u32(dsi->dev.of_node, "dsi,lanes", &val))
 		dsi->lanes = val;
+
 	return mipi_dsi_attach(dsi);
 }
 

drivers/misc/tinker_mcu.c

@@ -24,11 +24,15 @@
 #include <linux/workqueue.h>
 #include <linux/backlight.h>
 #include "tinker_mcu.h"
+#include <linux/fb.h>
 
 #define BL_DEBUG 0
 static struct tinker_mcu_data *g_mcu_data;
 static int connected = 0;
 static int lcd_bright_level = 0;
+static struct backlight_device *bl = NULL;
+
+#define MAX_BRIGHENESS 		(255)
 
 static int is_hex(char num)
 {
@@ -178,10 +182,40 @@ static int tinker_mcu_bl_get_brightness(struct backlight_device *bd)
 	return lcd_bright_level;
 }
 
+ int tinker_mcu_bl_update_status(struct backlight_device * bd)
+ {
+	int brightness = bd->props.brightness;
+
+	if (brightness > MAX_BRIGHENESS)
+		brightness = MAX_BRIGHENESS;
+
+	if (brightness <= 0)
+		brightness = 1;
+
+	if (bd->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bd->props.state & BL_CORE_SUSPENDED)
+		brightness = 0;
+
+	LOG_INFO("tinker_mcu_bl_update_status  brightness=%d power=%d fb_blank=%d state =%d  bd->props.brightness=%d\n", brightness, bd->props.power, bd->props.fb_blank, bd->props.state , bd->props.brightness);
+	return tinker_mcu_set_bright(brightness);
+}
+
 static const struct backlight_ops tinker_mcu_bl_ops = {
-	.get_brightness	= tinker_mcu_bl_get_brightness,
+	.get_brightness	= tinker_mcu_bl_get_brightness,//actual_brightness_show
+	.update_status	= tinker_mcu_bl_update_status,
+	.options 			= BL_CORE_SUSPENDRESUME,
 };
 
+struct backlight_device * tinker_mcu_get_backlightdev(void)
+{
+	if (!connected) {
+		printk("tinker_mcu_get_backlightdev is not ready\n");
+		return NULL;
+	}
+	return bl;
+}
 
 static ssize_t tinker_mcu_bl_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -196,7 +230,7 @@ static ssize_t tinker_mcu_bl_store(struct device *dev, struct device_attribute *
 
 	value = simple_strtoul(buf, NULL, 0);
 
-	if((value < 0) || (value > 255)) {
+	if((value < 0) || (value > MAX_BRIGHENESS)) {
 		LOG_ERR("Invalid value for backlight setting, value = %d\n", value);
 	} else
 		tinker_mcu_set_bright(value);
@@ -217,7 +251,6 @@ static int tinker_mcu_probe(struct i2c_client *client,
 	struct tinker_mcu_data *mcu_data;
 	int ret;
 	struct backlight_properties props;
-	struct backlight_device *bl;
 
 	LOG_INFO("address = 0x%x\n", client->addr);
 
@@ -245,7 +278,7 @@ static int tinker_mcu_probe(struct i2c_client *client,
 
 	memset(&props, 0, sizeof(props));
 	props.type = BACKLIGHT_RAW;
-	props.max_brightness = 255;
+	props.max_brightness = MAX_BRIGHENESS;
 
 	bl = backlight_device_register("panel_backlight", NULL, NULL,
 					   &tinker_mcu_bl_ops, &props);

drivers/misc/tinker_mcu_ili9881c.c

@@ -31,7 +31,7 @@ static struct tinker_mcu_data *g_mcu_ili9881c_data;
 static int connected = 0;
 static int lcd_bright_level = 0;
 int lcd_size_flag = 0;
-struct backlight_device *bl = NULL;;
+static struct backlight_device *bl = NULL;
 
 #define MAX_MCU_ILI9881C_PWM_WORKAROUND 	(9)
 #define MAX_MCU_ILI9881C_PWM 	(31)
@@ -203,8 +203,8 @@ static int tinker_mcu_ili9881c_bl_get_brightness(struct backlight_device *bd)
 
 	if (brightness > MAX_BRIGHENESS)
 		brightness = MAX_BRIGHENESS;
-	if (brightness < 0)
-		brightness = 0;
+	if (brightness <= 0)
+		brightness = 1;
 
 	if ( brightness > 0) {
 		brightness *= 12;