Commit 061489c6 authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/i915/dsb: single register write function for DSB.



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: default avatarShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: default avatarAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190920115930.27829-4-animesh.manna@intel.com
parent 67f3b58f
......@@ -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);
}
......@@ -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
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