drm/radeon: Add probing of clocks from device-tree

When we find no ROM we understand and a device-tree is present, see
if we can retreive clock info from there.

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

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_clocks.c b/drivers/gpu/drm/radeon/radeon_clocks.c
index f64936cc4dd9..14448a740ba6 100644
--- a/drivers/gpu/drm/radeon/radeon_clocks.c
+++ b/drivers/gpu/drm/radeon/radeon_clocks.c
@@ -91,6 +91,85 @@ uint32_t radeon_legacy_get_memory_clock(struct radeon_device *rdev)
         return mclk;
 }
 
+#ifdef CONFIG_OF
+/*
+ * Read XTAL (ref clock), SCLK and MCLK from Open Firmware device
+ * tree. Hopefully, ATI OF driver is kind enough to fill these
+ */
+static bool __devinit radeon_read_clocks_OF(struct drm_device *dev)
+{
+        struct radeon_device *rdev = dev->dev_private;
+        struct device_node *dp = rdev->pdev->dev.of_node;
+        const u32 *val;
+        struct radeon_pll *p1pll = &rdev->clock.p1pll;
+        struct radeon_pll *p2pll = &rdev->clock.p2pll;
+        struct radeon_pll *spll = &rdev->clock.spll;
+        struct radeon_pll *mpll = &rdev->clock.mpll;
+
+        if (dp == NULL)
+                return false;
+        val = of_get_property(dp, "ATY,RefCLK", NULL);
+        if (!val || !*val) {
+                printk(KERN_WARNING "radeonfb: No ATY,RefCLK property !\n");
+                return false;
+        }
+        p1pll->reference_freq = p2pll->reference_freq = (*val) / 10;
+        p1pll->reference_div = RREG32_PLL(RADEON_PPLL_REF_DIV) & 0x3ff;
+        if (p1pll->reference_div < 2)
+                p1pll->reference_div = 12;
+        p2pll->reference_div = p1pll->reference_div;    
+
+        /* These aren't in the device-tree */
+        if (rdev->family >= CHIP_R420) {
+                p1pll->pll_in_min = 100;
+                p1pll->pll_in_max = 1350;
+                p1pll->pll_out_min = 20000;
+                p1pll->pll_out_max = 50000;
+                p2pll->pll_in_min = 100;
+                p2pll->pll_in_max = 1350;
+                p2pll->pll_out_min = 20000;
+                p2pll->pll_out_max = 50000;
+        } else {
+                p1pll->pll_in_min = 40;
+                p1pll->pll_in_max = 500;
+                p1pll->pll_out_min = 12500;
+                p1pll->pll_out_max = 35000;
+                p2pll->pll_in_min = 40;
+                p2pll->pll_in_max = 500;
+                p2pll->pll_out_min = 12500;
+                p2pll->pll_out_max = 35000;
+        }
+
+        spll->reference_freq = mpll->reference_freq = p1pll->reference_freq;
+        spll->reference_div = mpll->reference_div =
+                RREG32_PLL(RADEON_M_SPLL_REF_FB_DIV) &
+                            RADEON_M_SPLL_REF_DIV_MASK;
+
+        val = of_get_property(dp, "ATY,SCLK", NULL);
+        if (val && *val)
+                rdev->clock.default_sclk = (*val) / 10;
+        else
+                rdev->clock.default_sclk =
+                        radeon_legacy_get_engine_clock(rdev);
+                        
+        val = of_get_property(dp, "ATY,MCLK", NULL);
+        if (val && *val)
+                rdev->clock.default_mclk = (*val) / 10;
+        else
+                rdev->clock.default_mclk =
+                        radeon_legacy_get_memory_clock(rdev);
+
+        DRM_INFO("Using device-tree clock info\n");
+        
+        return true;
+}
+#else
+static bool __devinit radeon_read_clocks_OF(struct drm_device *dev)
+{
+        return false;
+}
+#endif /* CONFIG_OF */
+
 void radeon_get_clock_info(struct drm_device *dev)
 {
         struct radeon_device *rdev = dev->dev_private;
@@ -105,6 +184,8 @@ void radeon_get_clock_info(struct drm_device *dev)
                 ret = radeon_atom_get_clock_info(dev);
         else
                 ret = radeon_combios_get_clock_info(dev);
+        if (!ret)
+                ret = radeon_read_clocks_OF(dev);
 
         if (ret) {
                 if (p1pll->reference_div < 2) {