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path: root/drivers/gpu/drm/i915/display/intel_dsb.c
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Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dsb.c')
-rw-r--r--drivers/gpu/drm/i915/display/intel_dsb.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index 2ed277670f15..f94cd6dc98b6 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -9,6 +9,12 @@
#define DSB_BUF_SIZE (2 * PAGE_SIZE)
+/* DSB opcodes. */
+#define DSB_OPCODE_SHIFT 24
+#define DSB_OPCODE_MMIO_WRITE 0x1
+#define DSB_BYTE_EN 0xF
+#define DSB_BYTE_EN_SHIFT 20
+
struct intel_dsb *
intel_dsb_get(struct intel_crtc *crtc)
{
@@ -76,5 +82,28 @@ void intel_dsb_put(struct intel_dsb *dsb)
i915_vma_unpin_and_release(&dsb->vma, 0);
mutex_unlock(&i915->drm.struct_mutex);
dsb->cmd_buf = NULL;
+ dsb->free_pos = 0;
+ }
+}
+
+void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val)
+{
+ struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
+ struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+ u32 *buf = dsb->cmd_buf;
+
+ if (!buf) {
+ I915_WRITE(reg, val);
+ return;
+ }
+
+ if (WARN_ON(dsb->free_pos >= DSB_BUF_SIZE)) {
+ DRM_DEBUG_KMS("DSB buffer overflow\n");
+ return;
}
+
+ buf[dsb->free_pos++] = val;
+ buf[dsb->free_pos++] = (DSB_OPCODE_MMIO_WRITE << DSB_OPCODE_SHIFT) |
+ (DSB_BYTE_EN << DSB_BYTE_EN_SHIFT) |
+ i915_mmio_reg_offset(reg);
}