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path: root/drivers/gpu/drm/vc4/vc4_hvs.c
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Diffstat (limited to 'drivers/gpu/drm/vc4/vc4_hvs.c')
-rw-r--r--drivers/gpu/drm/vc4/vc4_hvs.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 8098c5b21ba4..6fbab1c82cb1 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -100,12 +100,76 @@ int vc4_hvs_debugfs_regs(struct seq_file *m, void *unused)
}
#endif
+/* The filter kernel is composed of dwords each containing 3 9-bit
+ * signed integers packed next to each other.
+ */
+#define VC4_INT_TO_COEFF(coeff) (coeff & 0x1ff)
+#define VC4_PPF_FILTER_WORD(c0, c1, c2) \
+ ((((c0) & 0x1ff) << 0) | \
+ (((c1) & 0x1ff) << 9) | \
+ (((c2) & 0x1ff) << 18))
+
+/* The whole filter kernel is arranged as the coefficients 0-16 going
+ * up, then a pad, then 17-31 going down and reversed within the
+ * dwords. This means that a linear phase kernel (where it's
+ * symmetrical at the boundary between 15 and 16) has the last 5
+ * dwords matching the first 5, but reversed.
+ */
+#define VC4_LINEAR_PHASE_KERNEL(c0, c1, c2, c3, c4, c5, c6, c7, c8, \
+ c9, c10, c11, c12, c13, c14, c15) \
+ {VC4_PPF_FILTER_WORD(c0, c1, c2), \
+ VC4_PPF_FILTER_WORD(c3, c4, c5), \
+ VC4_PPF_FILTER_WORD(c6, c7, c8), \
+ VC4_PPF_FILTER_WORD(c9, c10, c11), \
+ VC4_PPF_FILTER_WORD(c12, c13, c14), \
+ VC4_PPF_FILTER_WORD(c15, c15, 0)}
+
+#define VC4_LINEAR_PHASE_KERNEL_DWORDS 6
+#define VC4_KERNEL_DWORDS (VC4_LINEAR_PHASE_KERNEL_DWORDS * 2 - 1)
+
+/* Recommended B=1/3, C=1/3 filter choice from Mitchell/Netravali.
+ * http://www.cs.utexas.edu/~fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
+ */
+static const u32 mitchell_netravali_1_3_1_3_kernel[] =
+ VC4_LINEAR_PHASE_KERNEL(0, -2, -6, -8, -10, -8, -3, 2, 18,
+ 50, 82, 119, 155, 187, 213, 227);
+
+static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
+ struct drm_mm_node *space,
+ const u32 *kernel)
+{
+ int ret, i;
+ u32 __iomem *dst_kernel;
+
+ ret = drm_mm_insert_node(&hvs->dlist_mm, space, VC4_KERNEL_DWORDS, 1,
+ 0);
+ if (ret) {
+ DRM_ERROR("Failed to allocate space for filter kernel: %d\n",
+ ret);
+ return ret;
+ }
+
+ dst_kernel = hvs->dlist + space->start;
+
+ for (i = 0; i < VC4_KERNEL_DWORDS; i++) {
+ if (i < VC4_LINEAR_PHASE_KERNEL_DWORDS)
+ writel(kernel[i], &dst_kernel[i]);
+ else {
+ writel(kernel[VC4_KERNEL_DWORDS - i - 1],
+ &dst_kernel[i]);
+ }
+ }
+
+ return 0;
+}
+
static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
{
struct platform_device *pdev = to_platform_device(dev);
struct drm_device *drm = dev_get_drvdata(master);
struct vc4_dev *vc4 = drm->dev_private;
struct vc4_hvs *hvs = NULL;
+ int ret;
hvs = devm_kzalloc(&pdev->dev, sizeof(*hvs), GFP_KERNEL);
if (!hvs)
@@ -119,6 +183,33 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
hvs->dlist = hvs->regs + SCALER_DLIST_START;
+ spin_lock_init(&hvs->mm_lock);
+
+ /* Set up the HVS display list memory manager. We never
+ * overwrite the setup from the bootloader (just 128b out of
+ * our 16K), since we don't want to scramble the screen when
+ * transitioning from the firmware's boot setup to runtime.
+ */
+ drm_mm_init(&hvs->dlist_mm,
+ HVS_BOOTLOADER_DLIST_END,
+ (SCALER_DLIST_SIZE >> 2) - HVS_BOOTLOADER_DLIST_END);
+
+ /* Set up the HVS LBM memory manager. We could have some more
+ * complicated data structure that allowed reuse of LBM areas
+ * between planes when they don't overlap on the screen, but
+ * for now we just allocate globally.
+ */
+ drm_mm_init(&hvs->lbm_mm, 0, 96 * 1024);
+
+ /* Upload filter kernels. We only have the one for now, so we
+ * keep it around for the lifetime of the driver.
+ */
+ ret = vc4_hvs_upload_linear_kernel(hvs,
+ &hvs->mitchell_netravali_filter,
+ mitchell_netravali_1_3_1_3_kernel);
+ if (ret)
+ return ret;
+
vc4->hvs = hvs;
return 0;
}
@@ -129,6 +220,12 @@ static void vc4_hvs_unbind(struct device *dev, struct device *master,
struct drm_device *drm = dev_get_drvdata(master);
struct vc4_dev *vc4 = drm->dev_private;
+ if (vc4->hvs->mitchell_netravali_filter.allocated)
+ drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);
+
+ drm_mm_takedown(&vc4->hvs->dlist_mm);
+ drm_mm_takedown(&vc4->hvs->lbm_mm);
+
vc4->hvs = NULL;
}