video: fbdev: pmag-ba-fb: Optimize Bt455 colormap addressing

Use the address autoincrement feature when accessing successive palette
entries and also skip loading a palette address in overlay register
assesses which do not use that address.  Provide a red/green/blue
register sequencer reset helper for use in overlay register assesses
where the state of the sequencer is not known.

References:

[1] "Bt454 Bt455 170 MHz Monolithic CMOS 16 Color Palette RAMDAC",
    Brooktree Corporation, Document Number: L454001, Rev. I

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --git a/drivers/video/fbdev/bt455.h b/drivers/video/fbdev/bt455.h
index a4bba5a49d774eaab11bf965bdb05cb6892647c7..dd1404b40611db952e5a8ba013a688a6887087ee 100644 (file)
--- a/drivers/video/fbdev/bt455.h
+++ b/drivers/video/fbdev/bt455.h
@@ -30,13 +30,17 @@ static inline void bt455_select_reg(struct bt455_regs *regs, int ir)
        regs->addr_cmap = ir & 0x0f;
 }
 
+static inline void bt455_reset_reg(struct bt455_regs *regs)
+{
+       mb();
+       regs->addr_clr = 0;
+}
+
 /*
  * Read/write to a Bt455 color map register.
  */
-static inline void bt455_read_cmap_entry(struct bt455_regs *regs,
-                                        int cr, u8 *grey)
+static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey)
 {
-       bt455_select_reg(regs, cr);
        mb();
        regs->addr_cmap_data;
        rmb();
@@ -45,10 +49,8 @@ static inline void bt455_read_cmap_entry(struct bt455_regs *regs,
        regs->addr_cmap_data;
 }
 
-static inline void bt455_write_cmap_entry(struct bt455_regs *regs,
-                                         int cr, u8 grey)
+static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey)
 {
-       bt455_select_reg(regs, cr);
        wmb();
        regs->addr_cmap_data = 0x0;
        wmb();
@@ -57,10 +59,8 @@ static inline void bt455_write_cmap_entry(struct bt455_regs *regs,
        regs->addr_cmap_data = 0x0;
 }
 
-static inline void bt455_write_ovly_entry(struct bt455_regs *regs,
-                                         int cr, u8 grey)
+static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey)
 {
-       bt455_select_reg(regs, cr);
        wmb();
        regs->addr_ovly = 0x0;
        wmb();
@@ -68,3 +68,23 @@ static inline void bt455_write_ovly_entry(struct bt455_regs *regs,
        wmb();
        regs->addr_ovly = 0x0;
 }
+
+static inline void bt455_read_cmap_entry(struct bt455_regs *regs,
+                                        int cr, u8 *grey)
+{
+       bt455_select_reg(regs, cr);
+       bt455_read_cmap_next(regs, grey);
+}
+
+static inline void bt455_write_cmap_entry(struct bt455_regs *regs,
+                                         int cr, u8 grey)
+{
+       bt455_select_reg(regs, cr);
+       bt455_write_cmap_next(regs, grey);
+}
+
+static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey)
+{
+       bt455_reset_reg(regs);
+       bt455_write_ovly_next(regs, grey);
+}

diff --git a/drivers/video/fbdev/pmag-aa-fb.c b/drivers/video/fbdev/pmag-aa-fb.c
index 6f4466c39529f4d343a74db1ebf95bb4db089d2e..ffe2dd482f840b51e83d3180bc327c1aefdc029e 100644 (file)
--- a/drivers/video/fbdev/pmag-aa-fb.c
+++ b/drivers/video/fbdev/pmag-aa-fb.c
@@ -122,8 +122,8 @@ static int aafb_cursor(struct fb_info *info, struct fb_cursor *cursor)
                u8 bg = cursor->image.bg_color ? 0xf : 0x0;
 
                bt455_write_cmap_entry(par->bt455, 8, bg);
-               bt455_write_cmap_entry(par->bt455, 9, bg);
-               bt455_write_ovly_entry(par->bt455, 0, fg);
+               bt455_write_cmap_next(par->bt455, bg);
+               bt455_write_ovly_next(par->bt455, fg);
        }
        if (cursor->set & (FB_CUR_SETSIZE | FB_CUR_SETSHAPE | FB_CUR_SETIMAGE))
                bt431_set_cursor(par->bt431,
@@ -212,7 +212,7 @@ static int pmagaafb_probe(struct device *dev)
 
        /* Init colormap. */
        bt455_write_cmap_entry(par->bt455, 0, 0x0);
-       bt455_write_cmap_entry(par->bt455, 1, 0xf);
+       bt455_write_cmap_next(par->bt455, 0xf);
 
        /* Init hardware cursor. */
        bt431_erase_cursor(par->bt431);