]> git.kernelconcepts.de Git - karo-tx-uboot.git/blobdiff - board/karo/common/fdt.c
karo: fdt: remove 'vbus-supply' from usbotg node when otg_mode=peripheral
[karo-tx-uboot.git] / board / karo / common / fdt.c
index c942e8af52753b73fb70a3ecf41bb53a2b1474d7..387208c78e4e317e36ce96a4079121c39812337f 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/list.h>
 #include <linux/fb.h>
 #include <jffs2/load_kernel.h>
+#include <malloc.h>
 
 #include "karo.h"
 
@@ -37,7 +38,6 @@ DECLARE_GLOBAL_DATA_PTR;
 
 static void karo_set_fdtsize(void *fdt)
 {
-       char fdt_size[9];
        size_t fdtsize = getenv_ulong("fdtsize", 16, 0);
 
        if (fdtsize == fdt_totalsize(fdt)) {
@@ -45,9 +45,35 @@ static void karo_set_fdtsize(void *fdt)
        }
        debug("FDT size changed from %u to %u\n",
                fdtsize, fdt_totalsize(fdt));
+       setenv_hex("fdtsize", fdt_totalsize(fdt));
+}
+
+static void *karo_fdt_load_dtb(void)
+{
+       int ret;
+       void *fdt = (void *)getenv_ulong("fdtaddr", 16, CONFIG_SYS_FDT_ADDR);
+
+       if (had_ctrlc()) {
+               printf("aborting DTB load\n");
+               return NULL;
+       }
+
+       /* clear FDT header in memory */
+       memset(fdt, 0, 4);
 
-       snprintf(fdt_size, sizeof(fdt_size), "%08x", fdt_totalsize(fdt));
-       setenv("fdtsize", fdt_size);
+       ret = karo_load_part("dtb", fdt, MAX_DTB_SIZE);
+       if (ret) {
+               printf("Failed to load dtb from flash: %d\n", ret);
+               return NULL;
+       }
+
+       if (fdt_check_header(fdt)) {
+               debug("No valid DTB in flash\n");
+               return NULL;
+       }
+       debug("Using DTB from flash\n");
+       karo_set_fdtsize(fdt);
+       return fdt;
 }
 
 void karo_fdt_move_fdt(void)
@@ -60,6 +86,8 @@ void karo_fdt_move_fdt(void)
                return;
        }
 
+       setenv("fdtsize", 0);
+
        if (!fdt_addr) {
                fdt_addr = CONFIG_SYS_FDT_ADDR;
                printf("fdtaddr is not set; using default: %08lx\n",
@@ -70,15 +98,22 @@ void karo_fdt_move_fdt(void)
        if (fdt == NULL) {
                fdt = (void *)gd->fdt_blob;
                if (fdt == NULL) {
-                       printf("Compiled in FDT not found\n");
-                       return;
+#ifdef CONFIG_OF_EMBED
+                       printf("Compiled in FDT not found");
+#else
+                       printf("No FDT found");
+#endif
+                       printf("; creating empty DTB\n");
+                       fdt = (void *)fdt_addr;
+                       fdt_create_empty_tree(fdt, 256);
+               } else {
+                       printf("No DTB in flash; using default DTB\n");
                }
                debug("Checking FDT header @ %p\n", fdt);
                if (fdt_check_header(fdt)) {
                        printf("ERROR: No valid DTB found at %p\n", fdt);
                        return;
                }
-               printf("No DTB in flash; using default DTB\n");
                debug("Moving FDT from %p..%p to %08lx..%08lx\n",
                        fdt, fdt + fdt_totalsize(fdt) - 1,
                        fdt_addr, fdt_addr + fdt_totalsize(fdt) - 1);
@@ -97,12 +132,13 @@ void karo_fdt_remove_node(void *blob, const char *node)
        debug("Removing node '%s' from DT\n", node);
 
        if (off < 0) {
-               printf("Could not find node '%s': %d\n", node, off);
+               printf("Could not find node '%s': %s\n", node,
+                       fdt_strerror(off));
        } else {
                ret = fdt_del_node(blob, off);
                if (ret)
-                       printf("Failed to remove node '%s': %d\n",
-                               node, ret);
+                       printf("Failed to remove node '%s': %s\n",
+                               node, fdt_strerror(ret));
        }
        karo_set_fdtsize(blob);
 }
@@ -113,7 +149,8 @@ void karo_fdt_enable_node(void *blob, const char *node, int enable)
 
        debug("%sabling node '%s'\n", enable ? "En" : "Dis", node);
        if (off < 0) {
-               printf("Could not find node '%s': %d\n", node, off);
+               printf("Could not find node '%s': %s\n", node,
+                       fdt_strerror(off));
                return;
        }
        fdt_set_node_status(blob, off,
@@ -122,56 +159,75 @@ void karo_fdt_enable_node(void *blob, const char *node, int enable)
        karo_set_fdtsize(blob);
 }
 
-static const char *karo_touchpanels[] = {
-       "ti,tsc2007",
-       "edt,edt-ft5x06",
-#ifdef CONFIG_MX28
-       "fsl,imx28-lradc",
-#endif
-};
-
 static void fdt_disable_tp_node(void *blob, const char *name)
 {
        int offs = fdt_node_offset_by_compatible(blob, -1, name);
 
-       if (offs < 0) {
-               debug("node '%s' not found: %d\n", name, offs);
-               return;
+       while (offs >= 0) {
+               debug("Disabling node '%s'\n", name);
+               fdt_set_node_status(blob, offs, FDT_STATUS_DISABLED, 0);
+               offs = fdt_node_offset_by_compatible(blob, offs, name);
        }
-
-       debug("Disabling node '%s'\n", name);
-       fdt_set_node_status(blob, offs, FDT_STATUS_DISABLED, 0);
 }
 
-void karo_fdt_fixup_touchpanel(void *blob)
+void karo_fdt_fixup_touchpanel(void *blob, const char *panels[],
+                       size_t num_panels)
 {
        int i;
        const char *model = getenv("touchpanel");
 
-       for (i = 0; i < ARRAY_SIZE(karo_touchpanels); i++) {
-               const char *tp = karo_touchpanels[i];
-
-               if (model != NULL && strcmp(model, tp) == 0)
-                       continue;
+       for (i = 0; i < num_panels; i++) {
+               const char *tp = panels[i];
 
                if (model != NULL) {
                        if (strcmp(model, tp) == 0)
                                continue;
-                       tp = strchr(tp, ',');
-                       if (tp != NULL && *tp != '\0' && strcmp(model, tp + 1) == 0)
+                       while (tp != NULL) {
+                               if (*tp != '\0' && strcmp(model, tp + 1) == 0)
+                                       break;
+                               tp = strpbrk(tp + 1, ",-");
+                       }
+                       if (tp != NULL)
                                continue;
                }
-               fdt_disable_tp_node(blob, karo_touchpanels[i]);
+               fdt_disable_tp_node(blob, panels[i]);
        }
        karo_set_fdtsize(blob);
 }
 
+static int karo_fdt_disable_node_phandle(void *blob, const char *parent,
+                                       const char *name)
+{
+       const uint32_t *ph;
+       int off;
+
+       off = fdt_path_offset(blob, parent);
+       if (off < 0) {
+               printf("Failed to find node '%s'\n", parent);
+               return off;
+       }
+
+       ph = fdt_getprop(blob, off, name, NULL);
+       if (ph == NULL) {
+               debug("Failed to find '%s' phandle in node '%s'\n", name,
+                       fdt_get_name(blob, off, NULL));
+               return -FDT_ERR_NOTFOUND;
+       }
+
+       off = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*ph));
+       if (off <= 0) {
+               printf("Failed to find '%s' node via phandle %04x\n",
+                       name, fdt32_to_cpu(*ph));
+               return -FDT_ERR_NOTFOUND;
+       }
+       return fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
+}
+
 void karo_fdt_fixup_usb_otg(void *blob, const char *node, const char *phy)
 {
        const char *otg_mode = getenv("otg_mode");
        int off;
        int ret;
-       const uint32_t *ph;
        int disable_otg = 0;
        int disable_phy_pins = 1;
 
@@ -194,6 +250,7 @@ void karo_fdt_fixup_usb_otg(void *blob, const char *node, const char *phy)
        } else if (otg_mode && strcmp(otg_mode, "otg") == 0) {
                debug("Setting dr_mode to 'host'\n");
                ret = fdt_setprop_string(blob, off, "dr_mode", "otg");
+               disable_phy_pins = 0;
        } else {
                if (otg_mode && strcmp(otg_mode, "none") != 0)
                        printf("Invalid 'otg_mode' setting '%s'; disabling usbotg port\n",
@@ -205,38 +262,124 @@ void karo_fdt_fixup_usb_otg(void *blob, const char *node, const char *phy)
        if ((!disable_phy_pins && !disable_otg) || ret)
                goto out;
 
+       ret = karo_fdt_disable_node_phandle(blob, node, "vbus-supply");
+       if (ret)
+               goto out;
+
        if (disable_otg) {
+               debug("Disabling usbphy\n");
                ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
                if (ret)
                        goto out;
-       }
-
-       ph = fdt_getprop(blob, off, phy, NULL);
-       if (ph == NULL) {
-               printf("Failed to find '%s' phandle in node '%s'\n", phy,
-                       fdt_get_name(blob, off, NULL));
-               goto out;
-       }
 
-       off = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*ph));
-       if (off <= 0) {
-               printf("Failed to find '%s' node via phandle %04x\n",
-                       phy, fdt32_to_cpu(*ph));
-               goto out;
+               ret = karo_fdt_disable_node_phandle(blob, node, phy);
+       } else if (disable_phy_pins) {
+               debug("Removing 'vbus-supply' from usbotg node\n");
+               fdt_delprop(blob, off, "vbus-supply");
        }
 
-       if (disable_otg) {
-               debug("Disabling usbphy\n");
-               ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
-       }
 out:
        if (ret)
-               printf("Failed to update usbotg: %d\n", ret);
+               printf("Failed to update usbotg: %s\n", fdt_strerror(ret));
        else
                debug("node '%s' updated\n", node);
        karo_set_fdtsize(blob);
 }
 
+static inline int karo_fdt_flexcan_enabled(void *blob)
+{
+       static const char *can_ifs[] = {
+               "can0",
+               "can1",
+       };
+       size_t i;
+
+       for (i = 0; i < ARRAY_SIZE(can_ifs); i++) {
+               const char *status;
+               int off = fdt_path_offset(blob, can_ifs[i]);
+
+               if (off < 0) {
+                       debug("node '%s' not found\n", can_ifs[i]);
+                       continue;
+               }
+               status = fdt_getprop(blob, off, "status", NULL);
+               if (status && strcmp(status, "okay") == 0) {
+                       debug("%s is enabled\n", can_ifs[i]);
+                       return 1;
+               }
+       }
+       debug("can driver is disabled\n");
+       return 0;
+}
+
+static inline void karo_fdt_set_lcd_pins(void *blob, const char *name)
+{
+       int off = fdt_path_offset(blob, name);
+       u32 ph;
+       const struct fdt_property *pc;
+       int len;
+
+       if (off < 0)
+               return;
+
+       ph = fdt_create_phandle(blob, off);
+       if (!ph)
+               return;
+
+       off = fdt_path_offset(blob, "display");
+       if (off < 0)
+               return;
+
+       pc = fdt_get_property(blob, off, "pinctrl-0", &len);
+       if (!pc || len < sizeof(ph))
+               return;
+
+       memcpy((void *)pc->data, &ph, sizeof(ph));
+       fdt_setprop_cell(blob, off, "pinctrl-0", ph);
+}
+
+void karo_fdt_fixup_flexcan(void *blob, int xcvr_present)
+{
+       int ret;
+       const char *xcvr_status = "disabled";
+       const char *otg_mode = getenv("otg_mode");
+
+       if (xcvr_present) {
+               if (karo_fdt_flexcan_enabled(blob)) {
+                       if (!is_lvds()) {
+                               debug("Changing LCD to use 23bits only\n");
+                               karo_fdt_set_lcd_pins(blob, "lcdif_23bit_pins_a");
+                               xcvr_status = NULL;
+                       }
+               } else if (!is_lvds()) {
+                       debug("Changing LCD to use 24bits\n");
+                       karo_fdt_set_lcd_pins(blob, "lcdif_24bit_pins_a");
+               }
+       } else {
+               int off = fdt_path_offset(blob, "can0");
+
+               if (off >= 0)
+                       fdt_delprop(blob, off, "xceiver-supply");
+               off = fdt_path_offset(blob, "can1");
+               if (off >= 0)
+                       fdt_delprop(blob, off, "xceiver-supply");
+               if (!is_lvds())
+                       karo_fdt_set_lcd_pins(blob, "lcdif_24bit_pins_a");
+       }
+
+       if (otg_mode && strcmp(otg_mode, "host") == 0)
+               karo_fdt_enable_node(blob, "can1", 0);
+
+       if (xcvr_status) {
+               debug("Disabling CAN XCVR\n");
+               ret = fdt_find_and_setprop(blob, "reg_can_xcvr", "status",
+                                       xcvr_status, strlen(xcvr_status) + 1, 1);
+               if (ret)
+                       printf("Failed to disable CAN transceiver switch: %s\n",
+                               fdt_strerror(ret));
+       }
+}
+
 void karo_fdt_del_prop(void *blob, const char *compat, phys_addr_t offs,
                        const char *prop)
 {
@@ -320,7 +463,7 @@ static int fdt_init_fb_mode(const void *blob, int off, struct fb_videomode *fb_m
        prop = fdt_getprop(blob, off, "vsync-active", NULL);
        if (prop)
                fb_mode->sync |= *prop ? FB_SYNC_VERT_HIGH_ACT : 0;
-#if defined(CONFIG_MX51) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
+
        prop = fdt_getprop(blob, off, "de-active", NULL);
        if (prop)
                fb_mode->sync |= *prop ? 0 : FB_SYNC_OE_LOW_ACT;
@@ -328,7 +471,7 @@ static int fdt_init_fb_mode(const void *blob, int off, struct fb_videomode *fb_m
        prop = fdt_getprop(blob, off, "pixelclk-active", NULL);
        if (prop)
                fb_mode->sync |= *prop ? 0 : FB_SYNC_CLK_LAT_FALL;
-#endif
+
        return 0;
 }
 
@@ -337,9 +480,10 @@ static int fdt_update_native_fb_mode(void *blob, int off)
        int ret;
        uint32_t ph;
 
-       ret = fdt_increase_size(blob, 32);
+       ret = fdt_increase_size(blob, 64);
        if (ret) {
-               printf("Warning: Failed to increase FDT size: %d\n", ret);
+               printf("Warning: Failed to increase FDT size: %s\n",
+                       fdt_strerror(ret));
        }
        debug("Creating phandle at offset %d\n", off);
        ph = fdt_create_phandle(blob, off);
@@ -356,7 +500,8 @@ static int fdt_update_native_fb_mode(void *blob, int off)
        debug("parent offset=%06x\n", off);
        ret = fdt_setprop_cell(blob, off, "native-mode", ph);
        if (ret)
-               printf("Failed to set property 'native-mode': %d\n", ret);
+               printf("Failed to set property 'native-mode': %s\n",
+                       fdt_strerror(ret));
        karo_set_fdtsize(blob);
        return ret;
 }
@@ -367,13 +512,15 @@ static int karo_fdt_find_video_timings(void *blob)
        const char *subnode = "display-timings";
 
        if (off < 0) {
-               debug("Could not find node 'display' in FDT: %d\n", off);
+               debug("Could not find node 'display' in FDT: %s\n",
+                       fdt_strerror(off));
                return off;
        }
 
        off = fdt_subnode_offset(blob, off, subnode);
        if (off < 0) {
-               debug("Could not find node '%s' in FDT: %d\n", subnode, off);
+               debug("Could not find node '%s' in FDT: %s\n", subnode,
+                       fdt_strerror(off));
        }
        return off;
 }
@@ -394,10 +541,12 @@ int karo_fdt_get_fb_mode(void *blob, const char *name, struct fb_videomode *fb_m
                if (d < 1)
                        return -EINVAL;
                if (d > 2) {
-                       debug("Skipping node @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
+                       debug("Skipping node @ %04x %s depth %d\n", off,
+                               fdt_get_name(blob, off, NULL), d);
                        continue;
                }
-               debug("parsing subnode @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
+               debug("parsing subnode @ %04x %s depth %d\n", off,
+                       fdt_get_name(blob, off, NULL), d);
 
                n = fdt_getprop(blob, off, "panel-name", &len);
                if (!n) {
@@ -431,7 +580,8 @@ int karo_fdt_get_fb_mode(void *blob, const char *name, struct fb_videomode *fb_m
        int ret;                                                        \
        ret = fdt_setprop_u32(blob, off, n, v);                         \
        if (ret) {                                                      \
-               printf("Failed to set property %s: %d\n", name, ret);   \
+               printf("Failed to set property %s: %s\n", name,         \
+                       fdt_strerror(ret));                             \
        }                                                               \
        ret;                                                            \
 })
@@ -451,25 +601,26 @@ int karo_fdt_create_fb_mode(void *blob, const char *name,
 
        ret = fdt_increase_size(blob, 512);
        if (ret) {
-               printf("Failed to increase FDT size: %d\n", ret);
+               printf("Failed to increase FDT size: %s\n", fdt_strerror(ret));
                return ret;
        }
 
-       printf("node '%s' offset=%d\n", "display", off);
        ret = fdt_subnode_offset(blob, off, subnode);
        if (ret < 0) {
-               debug("Could not find node '%s' in FDT: %d\n", subnode, ret);
+               debug("Could not find node '%s' in FDT: %s\n", subnode,
+                       fdt_strerror(ret));
                ret = fdt_add_subnode(blob, off, subnode);
                if (ret < 0) {
-                       printf("Failed to add %s subnode: %d\n", subnode, ret);
+                       printf("Failed to add %s subnode: %s\n", subnode,
+                               fdt_strerror(ret));
                        return ret;
                }
        }
 
-       printf("node '%s' offset=%d\n", subnode, ret);
        ret = fdt_add_subnode(blob, ret, name);
        if (ret < 0) {
-               printf("Failed to add %s subnode: %d\n", name, ret);
+               printf("Failed to add %s subnode: %s\n", name,
+                       fdt_strerror(ret));
                return ret;
        }
        off = ret;
@@ -510,25 +661,12 @@ int karo_fdt_create_fb_mode(void *blob, const char *name,
                        fb_mode->sync & FB_SYNC_VERT_HIGH_ACT ? 1 : 0);
        if (ret)
                goto out;
-
-#if defined(CONFIG_MX51) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
        ret = SET_FB_PROP("de-active",
                        !(fb_mode->sync & FB_SYNC_OE_LOW_ACT));
        if (ret)
                goto out;
        ret = SET_FB_PROP("pixelclk-active",
                        !(fb_mode->sync & FB_SYNC_CLK_LAT_FALL));
-       if (ret)
-               goto out;
-#else
-       /* TODO: make these configurable */
-       ret = SET_FB_PROP("de-active", 1);
-       if (ret)
-               goto out;
-       ret = SET_FB_PROP("pixelclk-active", 1);
-       if (ret)
-               goto out;
-#endif
 out:
        karo_set_fdtsize(blob);
        return ret;
@@ -543,22 +681,18 @@ int karo_fdt_update_fb_mode(void *blob, const char *name)
                return off;
 
        if (name == NULL) {
-               int parent = fdt_parent_offset(blob, off);
                int ret;
 
-               if (parent < 0) {
-                       printf("Failed to find parent of node '%s'\n",
-                               fdt_get_name(blob, off, NULL));
-                       return parent;
-               }
-               debug("parent offset=%06x\n", parent);
-               ret = fdt_set_node_status(blob, parent, FDT_STATUS_DISABLED, 0);
+               debug("Disabling node '%s' at %03x\n",
+                       fdt_get_name(blob, off, NULL), off);
+               ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
                return ret;
        }
 
        off = fdt_subnode_offset(blob, off, subnode);
        if (off < 0) {
-               debug("Could not find node '%s' in FDT: %d\n", subnode, off);
+               debug("Could not find node '%s' in FDT: %s\n", subnode,
+                       fdt_strerror(off));
                return off;
        }
        while (off > 0) {
@@ -571,10 +705,12 @@ int karo_fdt_update_fb_mode(void *blob, const char *name)
                if (d < 1)
                        return -EINVAL;
                if (d > 2) {
-                       debug("Skipping node @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
+                       debug("Skipping node @ %04x %s depth %d\n", off,
+                               fdt_get_name(blob, off, NULL), d);
                        continue;
                }
-               debug("parsing subnode @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
+               debug("parsing subnode @ %04x %s depth %d\n", off,
+                       fdt_get_name(blob, off, NULL), d);
 
                n = fdt_getprop(blob, off, "panel-name", &len);
                if (!n) {
@@ -603,75 +739,94 @@ int karo_fdt_update_fb_mode(void *blob, const char *name)
        return off;
 }
 
-static int karo_load_part(const char *part, void *addr, size_t len)
+#ifdef CONFIG_SYS_LVDS_IF
+int karo_fdt_get_lcd_bus_width(const void *blob, int default_width)
 {
-       int ret;
-       struct mtd_device *dev;
-       struct part_info *part_info;
-       u8 part_num;
-       size_t actual;
-
-       debug("Initializing mtd_parts\n");
-       ret = mtdparts_init();
-       if (ret)
-               return ret;
+       int off = fdt_path_offset(blob, "display");
 
-       debug("Trying to find NAND partition '%s'\n", part);
-       ret = find_dev_and_part(part, &dev, &part_num,
-                               &part_info);
-       if (ret) {
-               printf("Failed to find flash partition '%s': %d\n",
-                       part, ret);
+       if (off >= 0) {
+               const uint32_t *prop;
 
-               return ret;
-       }
-       debug("Found partition '%s': offset=%08x size=%08x\n",
-               part, part_info->offset, part_info->size);
-       if (part_info->size < len) {
-               printf("Warning: partition '%s' smaller than requested size: %u; truncating data to %u byte\n",
-                       part, len, part_info->size);
-               len = part_info->size;
-       }
-       debug("Reading NAND partition '%s' to %p\n", part, addr);
-       ret = nand_read_skip_bad(&nand_info[0], part_info->offset, &len,
-                               &actual, len, addr);
-       if (ret) {
-               printf("Failed to load partition '%s' to %p\n", part, addr);
-               return ret;
+               prop = fdt_getprop(blob, off, "fsl,data-width", NULL);
+               if (prop)
+                       return fdt32_to_cpu(*prop);
        }
-       if (actual < len)
-               printf("Read only %u of %u bytes due to bad blocks\n",
-                       actual, len);
+       return default_width;
+}
 
-       debug("Read %u byte from partition '%s' @ offset %08x\n",
-               len, part, part_info->offset);
-       return 0;
+int karo_fdt_get_lvds_mapping(const void *blob, int default_mapping)
+{
+       int off = fdt_path_offset(blob, "display");
+
+       if (off >= 0) {
+               const char *prop;
+
+               prop = fdt_getprop(blob, off, "fsl,data-mapping", NULL);
+               if (prop)
+                       return strcmp(prop, "jeida") == 0;
+       }
+       return default_mapping;
 }
 
-void *karo_fdt_load_dtb(void)
+u8 karo_fdt_get_lvds_channels(const void *blob)
 {
-       int ret;
-       void *fdt = (void *)getenv_ulong("fdtaddr", 16, CONFIG_SYS_FDT_ADDR);
+       static const char *lvds_chans[] = {
+               "lvds0",
+               "lvds1",
+       };
+       u8 lvds_chan_mask = 0;
+       int i;
 
-       if (tstc()) {
-               debug("aborting DTB load\n");
-               return NULL;
+       for (i = 0; i < ARRAY_SIZE(lvds_chans); i++) {
+               const char *status;
+               int off = fdt_path_offset(blob, lvds_chans[i]);
+
+               if (off < 0)
+                       continue;
+
+               status = fdt_getprop(blob, off, "status", NULL);
+               if (status && strcmp(status, "okay") == 0) {
+                       debug("%s is enabled\n", lvds_chans[i]);
+                       lvds_chan_mask |= 1 << i;
+               }
        }
+       return lvds_chan_mask;
+}
+#endif
 
-       /* clear FDT header in memory */
-       memset(fdt, 0, 4);
+int karo_fdt_get_backlight_polarity(const void *blob)
+{
+#ifdef CONFIG_SYS_LVDS_IF
+       const char *backlight_node = "/backlight0";
+#else
+       const char *backlight_node = "/backlight";
+#endif
+       int off = fdt_path_offset(blob, "backlight"); /* first try alias */
+       const struct fdt_property *prop;
+       int len;
 
-       ret = karo_load_part("dtb", fdt, MAX_DTB_SIZE);
-       if (ret) {
-               printf("Failed to load dtb from flash: %d\n", ret);
-               return NULL;
+       if (off < 0) {
+               /*
+                * if no 'backlight' alias exists try finding '/backlight0'
+                * or '/backlight' depending on LVDS or not
+                */
+               off = fdt_path_offset(blob, backlight_node);
+               if (off < 0) {
+                       printf("/backlight node not found in DT\n");
+                       return off;
+               }
        }
 
-       if (fdt_check_header(fdt)) {
-               debug("No valid DTB in flash\n");
-               return NULL;
+       prop = fdt_get_property(blob, off, "pwms", &len);
+       if (!prop)
+               printf("'pwms' property not found\n");
+       else
+               debug("'pwms' property has len %d\n", len);
+
+       len /= sizeof(u32);
+       if (prop && len > 3) {
+               const u32 *data = (const u32 *)prop->data;
+               return fdt32_to_cpu(data[3]) == 0;
        }
-       debug("Using DTB from flash\n");
-       karo_set_fdtsize(fdt);
-       return fdt;
+       return 0;
 }