From aeeafacd7241ca07a6054712485ac4bd595b3486 Mon Sep 17 00:00:00 2001
From: "fredrick.kim" <fredrick.kim@samsung.com>
Date: Thu, 4 Aug 2011 21:24:35 +0900
Subject: [PATCH] can get dpi info through kernel parameter

---
 drivers/video/backlight/emul_backlight.c | 10 ++----
 drivers/video/uvesafb.c                  | 40 ++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/drivers/video/backlight/emul_backlight.c b/drivers/video/backlight/emul_backlight.c
index 7c556ec363bc..37e390ac51ff 100644
--- a/drivers/video/backlight/emul_backlight.c
+++ b/drivers/video/backlight/emul_backlight.c
@@ -53,10 +53,9 @@ static int max_brightness = 10;
 static ssize_t bl_brightness_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	printk(KERN_INFO "%s: brightness = %d\n", __FUNCTION__, brightness);
-
 	/* handover to qemu layer */
 	brightness = (unsigned int)readl(svb_device->svb_mmreg);
+	printk(KERN_INFO "%s: brightness = %d\n", __FUNCTION__, brightness);
 
 	return sprintf(buf, "%d\n", brightness);
 }
@@ -113,7 +112,6 @@ static int __devinit svb_probe(struct pci_dev *pci_dev,
 			const struct pci_device_id *ent)
 {
 	int ret = -EBUSY;
-	printk(KERN_INFO "svb: svb_probe() is called.\n");
 
 	svb_device = kmalloc(sizeof(struct svb), GFP_KERNEL);
 	if (svb_device == NULL) {
@@ -176,8 +174,6 @@ static void __devexit svb_exit(struct pci_dev *pcidev)
 	iounmap(svb_device->svb_mmreg);
 	pci_disable_device(pcidev);
 	kfree(svb_device);
-
-	printk(KERN_INFO "svb_exit() is called.\n");
 }
 
 /* register pci driver
@@ -196,7 +192,7 @@ static struct pci_driver svb_pci_driver = {
 
 static int backlight_svb_init(void)
 {
-	pci_register_driver(&svb_pci_driver);
+	return pci_register_driver(&svb_pci_driver);
 }
 
 static int __init emul_backlight_class_init(void)
@@ -215,7 +211,7 @@ static int __init emul_backlight_class_init(void)
 	for (i=0; i < ARRAY_SIZE(emul_bl_device_attrib); i++) {
 		ret = device_create_file(emul_backlight_dev, emul_bl_device_attrib[i]);
 		if (ret != 0) {
-			printk(KERN_ERR, "emul_bl: Failed to create attr %d: %d\n", i, ret);
+			printk(KERN_ERR "emul_bl: Failed to create attr %d: %d\n", i, ret);
 			return ret;
 		}
 	}
diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c
index 54fbb2995a5f..e0963625ce99 100644
--- a/drivers/video/uvesafb.c
+++ b/drivers/video/uvesafb.c
@@ -270,16 +270,56 @@ static struct uvesafb_ktask *uvesafb_prep(void)
 	return task;
 }
 
+static int my_atoi(const char *name)
+{
+    int val = 0;
+
+    for (;; name++) {
+        switch (*name) {
+            case '0' ... '9':
+                val = 10*val+(*name-'0');
+                break;
+            default:
+                return val;
+        }
+    }
+}
+
+extern char *saved_command_line;
+#define DPI_DEF_VALUE		2400
+#define DPI_MIN_VALUE		1000
+#define DPI_MAX_VALUE		4800
+
 static void uvesafb_setup_var(struct fb_var_screeninfo *var,
 		struct fb_info *info, struct vbe_mode_ib *mode)
 {
 	struct uvesafb_par *par = info->par;
+	char *ps;
+	char dpi_info[16];
+	int dpi = DPI_DEF_VALUE;		/* default value */
 
 	var->vmode = FB_VMODE_NONINTERLACED;
 	var->sync = FB_SYNC_VERT_HIGH_ACT;
 
 	var->xres = mode->x_res;
 	var->yres = mode->y_res;
+
+	/* panel physical width/height(mm) */
+	ps = strstr(saved_command_line, "dpi=");
+	if (ps != NULL) {
+		ps += 4;
+		strncpy(dpi_info, ps, 4);
+		dpi = my_atoi(dpi_info);
+		if (dpi < DPI_MIN_VALUE || dpi > DPI_MAX_VALUE)
+			dpi = DPI_DEF_VALUE;
+	}
+
+	var->height = (var->yres * 254 / dpi);
+	var->width = (var->xres * 254 / dpi);
+	//printk(KERN_INFO "dpi value = %d\n", dpi);
+	//printk(KERN_INFO "var->yres = %d, var->xres = %d\n", var->yres, var->xres);
+	//printk(KERN_INFO "var->height = %d, var->width = %d\n", var->height, var->width);
+
 	var->xres_virtual = mode->x_res;
 	var->yres_virtual = (par->ypan) ?
 			info->fix.smem_len / mode->bytes_per_scan_line :
-- 
2.34.1