powerpc/5121: shared DIU framebuffer support

MPC5121 DIU configuration/setup as initialized by the boot
loader currently will get lost while booting Linux. As a
result displaying the boot splash is not possible through
the boot process.

To prevent this we reserve configured DIU frame buffer
address range while booting and preserve AOI descriptor
and gamma table so that DIU continues displaying through
the whole boot process. On first open from user space
DIU frame buffer driver releases the reserved frame
buffer area and continues to operate as usual.

Signed-off-by: John Rigby <jcrigby@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/video/fsl-diu-fb.c b/drivers/video/fsl-diu-fb.c
index 48905d5f4e8d..db3e360e6aad 100644
--- a/drivers/video/fsl-diu-fb.c
+++ b/drivers/video/fsl-diu-fb.c
@@ -1108,6 +1108,10 @@ static int fsl_diu_open(struct fb_info *info, int user)
         struct mfb_info *mfbi = info->par;
         int res = 0;
 
+        /* free boot splash memory on first /dev/fb0 open */
+        if (!mfbi->index && diu_ops.release_bootmem)
+                diu_ops.release_bootmem();
+
         spin_lock(&diu_lock);
         mfbi->count++;
         if (mfbi->count == 1) {
@@ -1435,6 +1439,7 @@ static int __devinit fsl_diu_probe(struct of_device *ofdev,
         int ret, i, error = 0;
         struct resource res;
         struct fsl_diu_data *machine_data;
+        int diu_mode;
 
         machine_data = kzalloc(sizeof(struct fsl_diu_data), GFP_KERNEL);
         if (!machine_data)
@@ -1471,7 +1476,9 @@ static int __devinit fsl_diu_probe(struct of_device *ofdev,
                 goto error2;
         }
 
-        out_be32(&dr.diu_reg->diu_mode, 0);             /* disable DIU anyway*/
+        diu_mode = in_be32(&dr.diu_reg->diu_mode);
+        if (diu_mode != MFB_MODE1)
+                out_be32(&dr.diu_reg->diu_mode, 0);     /* disable DIU */
 
         /* Get the IRQ of the DIU */
         machine_data->irq = irq_of_parse_and_map(np, 0);
@@ -1519,7 +1526,13 @@ static int __devinit fsl_diu_probe(struct of_device *ofdev,
         machine_data->dummy_ad->offset_xyd = 0;
         machine_data->dummy_ad->next_ad = 0;
 
-        out_be32(&dr.diu_reg->desc[0], machine_data->dummy_ad->paddr);
+        /*
+         * Let DIU display splash screen if it was pre-initialized
+         * by the bootloader, set dummy area descriptor otherwise.
+         */
+        if (diu_mode != MFB_MODE1)
+                out_be32(&dr.diu_reg->desc[0], machine_data->dummy_ad->paddr);
+
         out_be32(&dr.diu_reg->desc[1], machine_data->dummy_ad->paddr);
         out_be32(&dr.diu_reg->desc[2], machine_data->dummy_ad->paddr);