drm/ast: POST chip at probe time if VGA not enabled

We need to do it on machines without a BIOS such as POWER8. Also
for detection to work without triggering PCIe errors, we need
to enable VGA early on, inside ast_detect_chip().

While touching those files, replace a few hard coded register
numbers with the corresponding symbolic constant.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index a24cad4..7485ff9 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -384,6 +384,9 @@ int ast_bo_push_sysram(struct ast_bo *bo);
 int ast_mmap(struct file *filp, struct vm_area_struct *vma);
 
 /* ast post */
+void ast_enable_vga(struct drm_device *dev);
+void ast_enable_mmio(struct drm_device *dev);
+bool ast_is_vga_enabled(struct drm_device *dev);
 void ast_post_gpu(struct drm_device *dev);
 u32 ast_mindwm(struct ast_private *ast, u32 r);
 void ast_moutdwm(struct ast_private *ast, u32 r, u32 v);

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index c2ff793..556d065 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -63,7 +63,7 @@ uint8_t ast_get_index_reg_mask(struct ast_private *ast,
 }
 
 
-static int ast_detect_chip(struct drm_device *dev)
+static int ast_detect_chip(struct drm_device *dev, bool *need_post)
 {
        struct ast_private *ast = dev->dev_private;
        uint32_t data, jreg;
@@ -109,6 +109,21 @@ static int ast_detect_chip(struct drm_device *dev)
                }
        }
 
+       /*
+        * If VGA isn't enabled, we need to enable now or subsequent
+        * access to the scratch registers will fail. We also inform
+        * our caller that it needs to POST the chip
+        * (Assumption: VGA not enabled -> need to POST)
+        */
+       if (!ast_is_vga_enabled(dev)) {
+               ast_enable_vga(dev);
+               ast_enable_mmio(dev);
+               DRM_INFO("VGA not enabled on entry, requesting chip POST\n");
+               *need_post = true;
+       } else
+               *need_post = false;
+
+       /* Check if we support wide screen */
        switch (ast->chip) {
        case AST1180:
                ast->support_wide_screen = true;
@@ -124,6 +139,7 @@ static int ast_detect_chip(struct drm_device *dev)
                        ast->support_wide_screen = true;
                else {
                        ast->support_wide_screen = false;
+                       /* Read SCU7c (silicon revision register) */
                        ast_write32(ast, 0xf004, 0x1e6e0000);
                        ast_write32(ast, 0xf000, 0x1);
                        data = ast_read32(ast, 0x1207c);
@@ -136,11 +152,23 @@ static int ast_detect_chip(struct drm_device *dev)
                break;
        }
 
+       /* Check 3rd Tx option (digital output afaik) */
        ast->tx_chip_type = AST_TX_NONE;
+
+       /*
+        * VGACRA3 Enhanced Color Mode Register, check if DVO is already
+        * enabled, in that case, assume we have a SIL164 TMDS transmitter
+        */
        jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xff);
        if (jreg & 0x80)
                ast->tx_chip_type = AST_TX_SIL164;
+
        if ((ast->chip == AST2300) || (ast->chip == AST2400)) {
+               /*
+                * On AST2300 and 2400, look the configuration set by the SoC in
+                * the SOC scratch register #1 bits 11:8 (interestingly marked
+                * as "reserved" in the spec
+                */
                jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
                switch (jreg) {
                case 0x04:
@@ -161,6 +189,17 @@ static int ast_detect_chip(struct drm_device *dev)
                }
        }
 
+       /* Print stuff for diagnostic purposes */
+       switch(ast->tx_chip_type) {
+       case AST_TX_SIL164:
+               DRM_INFO("Using Sil164 TMDS transmitter\n");
+               break;
+       case AST_TX_DP501:
+               DRM_INFO("Using DP501 DisplayPort transmitter\n");
+               break;
+       default:
+               DRM_INFO("Analog VGA only\n");
+       }
        return 0;
 }
 
@@ -345,6 +384,7 @@ static u32 ast_get_vram_info(struct drm_device *dev)
 int ast_driver_load(struct drm_device *dev, unsigned long flags)
 {
        struct ast_private *ast;
+       bool need_post;
        int ret = 0;
 
        ast = kzalloc(sizeof(struct ast_private), GFP_KERNEL);
@@ -379,7 +419,7 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
                }
        }
 
-       ast_detect_chip(dev);
+       ast_detect_chip(dev, &need_post);
 
        if (ast->chip != AST1180) {
                ast_get_dram_info(dev);
@@ -387,6 +427,9 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
                DRM_INFO("dram %d %d %d %08x\n", ast->mclk, ast->dram_type, ast->dram_bus_width, ast->vram_size);
        }
 
+       if (need_post)
+               ast_post_gpu(dev);
+
        ret = ast_mm_init(ast);
        if (ret)
                goto out_free;

diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index 38d437f..810c51d 100644 (file)
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c
@@ -33,18 +33,23 @@
 
 static void ast_init_dram_2300(struct drm_device *dev);
 
-static void
-ast_enable_vga(struct drm_device *dev)
+void ast_enable_vga(struct drm_device *dev)
+{
+       struct ast_private *ast = dev->dev_private;
+
+       ast_io_write8(ast, AST_IO_VGA_ENABLE_PORT, 0x01);
+       ast_io_write8(ast, AST_IO_MISC_PORT_WRITE, 0x01);
+}
+
+void ast_enable_mmio(struct drm_device *dev)
 {
        struct ast_private *ast = dev->dev_private;
 
-       ast_io_write8(ast, 0x43, 0x01);
-       ast_io_write8(ast, 0x42, 0x01);
+       ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa1, 0xff, 0x04);
 }
 
-#if 0 /* will use later */
-static bool
-ast_is_vga_enabled(struct drm_device *dev)
+
+bool ast_is_vga_enabled(struct drm_device *dev)
 {
        struct ast_private *ast = dev->dev_private;
        u8 ch;
@@ -52,7 +57,7 @@ ast_is_vga_enabled(struct drm_device *dev)
        if (ast->chip == AST1180) {
                /* TODO 1180 */
        } else {
-               ch = ast_io_read8(ast, 0x43);
+               ch = ast_io_read8(ast, AST_IO_VGA_ENABLE_PORT);
                if (ch) {
                        ast_open_key(ast);
                        ch = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb6, 0xff);
@@ -61,7 +66,6 @@ ast_is_vga_enabled(struct drm_device *dev)
        }
        return 0;
 }
-#endif
 
 static const u8 extreginfo[] = { 0x0f, 0x04, 0x1c, 0xff };
 static const u8 extreginfo_ast2300a0[] = { 0x0f, 0x04, 0x1c, 0xff };
@@ -371,6 +375,7 @@ void ast_post_gpu(struct drm_device *dev)
        pci_write_config_dword(ast->dev->pdev, 0x04, reg);
 
        ast_enable_vga(dev);
+       ast_enable_mmio(dev);
        ast_open_key(ast);
        ast_set_def_ext_reg(dev);