From 061489c65ff57ee9f757d7a519fb9a09e5fbadd6 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Mon, 23 Sep 2019 10:09:23 +0300
Subject: drm/i915/dsb: single register write function for DSB.
Git-commit: 061489c65ff57ee9f757d7a519fb9a09e5fbadd6
Patch-mainline: v5.5-rc1
References: bsc#1152489
DSB support single register write through opcode 0x1. Generic
api created which accumulate all single register write in a batch
buffer and once DSB is triggered, it will program all the registers
at the same time.
v1: Initial version.
v2: Unused macro removed and cosmetic changes done. (Shashank)
v3: set free_pos to zero in dsb-put() instead dsb-get() and
a cosmetic change. (Shashank)
v4: macro of indexed-write is moved. (Shashank)
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190920115930.27829-4-animesh.manna@intel.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/i915/display/intel_dsb.c | 29 ++++++++++++++++++++++++
drivers/gpu/drm/i915/display/intel_dsb.h | 9 ++++++++
2 files changed, 38 insertions(+)
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);
}
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
index b8639864df50..839cbf621fa2 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.h
+++ b/drivers/gpu/drm/i915/display/intel_dsb.h
@@ -8,6 +8,8 @@
#include <linux/types.h>
+#include "i915_reg.h"
+
struct intel_crtc;
struct i915_vma;
@@ -24,10 +26,17 @@ struct intel_dsb {
enum dsb_id id;
u32 *cmd_buf;
struct i915_vma *vma;
+
+ /*
+ * free_pos will point the first free entry position
+ * and help in calculating tail of command buffer.
+ */
+ int free_pos;
};
struct intel_dsb *
intel_dsb_get(struct intel_crtc *crtc);
void intel_dsb_put(struct intel_dsb *dsb);
+void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val);
#endif
--
2.28.0