[PATCH 1/2] drm/amdgpu: imlement mmio byte access helpers

[Monk.Liu@xxxxxxx (Monk Liu)]

mailbox register can be accessed with a byte boundry according
to BIF team, so this patch prepares register byte access
and will be used by following patches

Change-Id: I1e84f1c6e8e75dc42eb5be09c492fa5e7eb7502a
Signed-off-by: Monk Liu <Monk.Liu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  6 ++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 26 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 292c7e7..72385bb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1635,6 +1635,9 @@ uint32_t amdgpu_mm_rreg(struct amdgpu_device *adev, uint32_t reg,
 			uint32_t acc_flags);
 void amdgpu_mm_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v,
 		    uint32_t acc_flags);
+void amdgpu_mm_wreg8(struct amdgpu_device *adev, uint32_t offset, uint8_t value);
+uint8_t amdgpu_mm_rreg8(struct amdgpu_device *adev, uint32_t offset);
+
 u32 amdgpu_io_rreg(struct amdgpu_device *adev, u32 reg);
 void amdgpu_io_wreg(struct amdgpu_device *adev, u32 reg, u32 v);
 
@@ -1658,6 +1661,9 @@ int emu_soc_asic_init(struct amdgpu_device *adev);
 #define RREG32_NO_KIQ(reg) amdgpu_mm_rreg(adev, (reg), AMDGPU_REGS_NO_KIQ)
 #define WREG32_NO_KIQ(reg, v) amdgpu_mm_wreg(adev, (reg), (v), AMDGPU_REGS_NO_KIQ)
 
+#define RREG8(reg) amdgpu_mm_rreg8(adev, (reg))
+#define WREG8(reg, v) amdgpu_mm_wreg8(adev, (reg), (v))
+
 #define RREG32(reg) amdgpu_mm_rreg(adev, (reg), 0)
 #define RREG32_IDX(reg) amdgpu_mm_rreg(adev, (reg), AMDGPU_REGS_IDX)
 #define DREG32(reg) printk(KERN_INFO "REGISTER: " #reg " : 0x%08X\n", amdgpu_mm_rreg(adev, (reg), 0))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 65584f6..c8e1940 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -121,6 +121,32 @@ uint32_t amdgpu_mm_rreg(struct amdgpu_device *adev, uint32_t reg,
 	return ret;
 }
 
+/*
+ * MMIO register read with bytes helper functions
+ * @offset:bytes offset from MMIO start
+ *
+*/
+
+uint8_t amdgpu_mm_rreg8(struct amdgpu_device *adev, uint32_t offset) {
+	if (offset < adev->rmmio_size)
+		return (readb(adev->rmmio + offset));
+	BUG();
+}
+
+/*
+ * MMIO register write with bytes helper functions
+ * @offset:bytes offset from MMIO start
+ * @value: the value want to be written to the register
+ *
+*/
+void amdgpu_mm_wreg8(struct amdgpu_device *adev, uint32_t offset, uint8_t value) {
+	if (offset < adev->rmmio_size)
+		writeb(value, adev->rmmio + offset);
+	else
+		BUG();
+}
+
+
 void amdgpu_mm_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v,
 		    uint32_t acc_flags)
 {
-- 
2.7.4