[PATCH] fbdev: framebuffer driver for Geode GX

A framebuffer driver for the display controller in AMD Geode GX processors
(Geode GX533, Geode GX500 etc.).  Tested at 640x480, 800x600, 1024x768 and
1280x1024 at 8, 16, and 24 bpp with both CRT and TFT.  No accelerated features
currently implemented and compression remains disabled.

This driver requires that the BIOS (or the SoftVG/Firmbase code in the BIOS)
has created an appropriate virtual PCI header.

Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 156 insertions, 0 deletions

diff --git a/drivers/video/geode/display_gx.c b/drivers/video/geode/display_gx.c
new file mode 100644
index 000000000000..825c3405f5c2
--- /dev/null
+++ b/drivers/video/geode/display_gx.c
@@ -0,0 +1,156 @@
+/*
+ * Geode GX display controller.
+ *
+ *   Copyright (C) 2005 Arcom Control Systems Ltd.
+ *
+ *   Portions from AMD's original 2.4 driver:
+ *     Copyright (C) 2004 Advanced Micro Devices, Inc.
+ *
+ *   This program is free software; you can redistribute it and/or modify it
+ *   under the terms of the GNU General Public License as published by * the
+ *   Free Software Foundation; either version 2 of the License, or * (at your
+ *   option) any later version.
+ */
+#include <linux/spinlock.h>
+#include <linux/fb.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+#include <asm/div64.h>
+#include <asm/delay.h>
+
+#include "geodefb.h"
+#include "display_gx.h"
+
+int gx_frame_buffer_size(void)
+{
+        /* Assuming 16 MiB. */
+        return 16*1024*1024;
+}
+
+int gx_line_delta(int xres, int bpp)
+{
+        /* Must be a multiple of 8 bytes. */
+        return (xres * (bpp >> 3) + 7) & ~0x7;
+}
+
+static void gx_set_mode(struct fb_info *info)
+{
+        struct geodefb_par *par = info->par;
+        u32 gcfg, dcfg;
+        int hactive, hblankstart, hsyncstart, hsyncend, hblankend, htotal;
+        int vactive, vblankstart, vsyncstart, vsyncend, vblankend, vtotal;
+
+        /* Unlock the display controller registers. */
+        readl(par->dc_regs + DC_UNLOCK);
+        writel(DC_UNLOCK_CODE, par->dc_regs + DC_UNLOCK);
+
+        gcfg = readl(par->dc_regs + DC_GENERAL_CFG);
+        dcfg = readl(par->dc_regs + DC_DISPLAY_CFG);
+
+        /* Disable the timing generator. */
+        dcfg &= ~(DC_DCFG_TGEN);
+        writel(dcfg, par->dc_regs + DC_DISPLAY_CFG);
+
+        /* Wait for pending memory requests before disabling the FIFO load. */
+        udelay(100);
+
+        /* Disable FIFO load and compression. */
+        gcfg &= ~(DC_GCFG_DFLE | DC_GCFG_CMPE | DC_GCFG_DECE);
+        writel(gcfg, par->dc_regs + DC_GENERAL_CFG);
+
+        /* Setup DCLK and its divisor. */
+        par->vid_ops->set_dclk(info);
+
+        /*
+         * Setup new mode.
+         */
+
+        /* Clear all unused feature bits. */
+        gcfg &= DC_GCFG_YUVM | DC_GCFG_VDSE;
+        dcfg = 0;
+
+        /* Set FIFO priority (default 6/5) and enable. */
+        /* FIXME: increase fifo priority for 1280x1024 and higher modes? */
+        gcfg |= (6 << DC_GCFG_DFHPEL_POS) | (5 << DC_GCFG_DFHPSL_POS) | DC_GCFG_DFLE;
+
+        /* Framebuffer start offset. */
+        writel(0, par->dc_regs + DC_FB_ST_OFFSET);
+
+        /* Line delta and line buffer length. */
+        writel(info->fix.line_length >> 3, par->dc_regs + DC_GFX_PITCH);
+        writel(((info->var.xres * info->var.bits_per_pixel/8) >> 3) + 2,
+               par->dc_regs + DC_LINE_SIZE);
+
+        /* Enable graphics and video data and unmask address lines. */
+        dcfg |= DC_DCFG_GDEN | DC_DCFG_VDEN | DC_DCFG_A20M | DC_DCFG_A18M;
+
+        /* Set pixel format. */
+        switch (info->var.bits_per_pixel) {
+        case 8:
+                dcfg |= DC_DCFG_DISP_MODE_8BPP;
+                break;
+        case 16:
+                dcfg |= DC_DCFG_DISP_MODE_16BPP;
+                dcfg |= DC_DCFG_16BPP_MODE_565;
+                break;
+        case 32:
+                dcfg |= DC_DCFG_DISP_MODE_24BPP;
+                dcfg |= DC_DCFG_PALB;
+                break;
+        }
+
+        /* Enable timing generator. */
+        dcfg |= DC_DCFG_TGEN;
+
+        /* Horizontal and vertical timings. */
+        hactive = info->var.xres;
+        hblankstart = hactive;
+        hsyncstart = hblankstart + info->var.right_margin;
+        hsyncend =  hsyncstart + info->var.hsync_len;
+        hblankend = hsyncend + info->var.left_margin;
+        htotal = hblankend;
+
+        vactive = info->var.yres;
+        vblankstart = vactive;
+        vsyncstart = vblankstart + info->var.lower_margin;
+        vsyncend =  vsyncstart + info->var.vsync_len;
+        vblankend = vsyncend + info->var.upper_margin;
+        vtotal = vblankend;
+
+        writel((hactive - 1)     | ((htotal - 1) << 16),    par->dc_regs + DC_H_ACTIVE_TIMING);
+        writel((hblankstart - 1) | ((hblankend - 1) << 16), par->dc_regs + DC_H_BLANK_TIMING);
+        writel((hsyncstart - 1)  | ((hsyncend - 1) << 16),  par->dc_regs + DC_H_SYNC_TIMING);
+
+        writel((vactive - 1)     | ((vtotal - 1) << 16),    par->dc_regs + DC_V_ACTIVE_TIMING);
+        writel((vblankstart - 1) | ((vblankend - 1) << 16), par->dc_regs + DC_V_BLANK_TIMING);
+        writel((vsyncstart - 1)  | ((vsyncend - 1) << 16),  par->dc_regs + DC_V_SYNC_TIMING);
+
+        /* Write final register values. */
+        writel(dcfg, par->dc_regs + DC_DISPLAY_CFG);
+        writel(gcfg, par->dc_regs + DC_GENERAL_CFG);
+
+        par->vid_ops->configure_display(info);
+
+        /* Relock display controller registers */
+        writel(0, par->dc_regs + DC_UNLOCK);
+}
+
+static void gx_set_hw_palette_reg(struct fb_info *info, unsigned regno,
+                                   unsigned red, unsigned green, unsigned blue)
+{
+        struct geodefb_par *par = info->par;
+        int val;
+
+        /* Hardware palette is in RGB 8-8-8 format. */
+        val  = (red   << 8) & 0xff0000;
+        val |= (green)      & 0x00ff00;
+        val |= (blue  >> 8) & 0x0000ff;
+
+        writel(regno, par->dc_regs + DC_PAL_ADDRESS);
+        writel(val, par->dc_regs + DC_PAL_DATA);
+}
+
+struct geode_dc_ops gx_dc_ops = {
+        .set_mode        = gx_set_mode,
+        .set_palette_reg = gx_set_hw_palette_reg,
+};