drm/radeon/kms: clean up i2c

- Change reg/mask names to match what we use internally
and in the bios
- Clarify how i2c over gpio on radeon actually works

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 22 insertions, 8 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 491a1ec81a4c..20847a2fc4dc 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -89,24 +89,38 @@ enum radeon_tv_std {
         TV_STD_PAL_CN,
 };
 
+/* radeon gpio-based i2c
+ * 1. "mask" reg and bits
+ *    grabs the gpio pins for software use
+ *    0=not held  1=held
+ * 2. "a" reg and bits
+ *    output pin value
+ *    0=low 1=high
+ * 3. "en" reg and bits
+ *    sets the pin direction
+ *    0=input 1=output
+ * 4. "y" reg and bits
+ *    input pin value
+ *    0=low 1=high
+ */
 struct radeon_i2c_bus_rec {
         bool valid;
         uint32_t mask_clk_reg;
         uint32_t mask_data_reg;
         uint32_t a_clk_reg;
         uint32_t a_data_reg;
-        uint32_t put_clk_reg;
-        uint32_t put_data_reg;
-        uint32_t get_clk_reg;
-        uint32_t get_data_reg;
+        uint32_t en_clk_reg;
+        uint32_t en_data_reg;
+        uint32_t y_clk_reg;
+        uint32_t y_data_reg;
         uint32_t mask_clk_mask;
         uint32_t mask_data_mask;
-        uint32_t put_clk_mask;
-        uint32_t put_data_mask;
-        uint32_t get_clk_mask;
-        uint32_t get_data_mask;
         uint32_t a_clk_mask;
         uint32_t a_data_mask;
+        uint32_t en_clk_mask;
+        uint32_t en_data_mask;
+        uint32_t y_clk_mask;
+        uint32_t y_data_mask;
 };
 
 struct radeon_tmds_pll {