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>

5 files changed, 86 insertions, 67 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 2ed88a82093..cd07c0e9122 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -82,18 +82,18 @@ static inline struct radeon_i2c_bus_rec radeon_lookup_gpio(struct drm_device
 
         i2c.mask_clk_reg = le16_to_cpu(gpio.usClkMaskRegisterIndex) * 4;
         i2c.mask_data_reg = le16_to_cpu(gpio.usDataMaskRegisterIndex) * 4;
-        i2c.put_clk_reg = le16_to_cpu(gpio.usClkEnRegisterIndex) * 4;
-        i2c.put_data_reg = le16_to_cpu(gpio.usDataEnRegisterIndex) * 4;
-        i2c.get_clk_reg = le16_to_cpu(gpio.usClkY_RegisterIndex) * 4;
-        i2c.get_data_reg = le16_to_cpu(gpio.usDataY_RegisterIndex) * 4;
+        i2c.en_clk_reg = le16_to_cpu(gpio.usClkEnRegisterIndex) * 4;
+        i2c.en_data_reg = le16_to_cpu(gpio.usDataEnRegisterIndex) * 4;
+        i2c.y_clk_reg = le16_to_cpu(gpio.usClkY_RegisterIndex) * 4;
+        i2c.y_data_reg = le16_to_cpu(gpio.usDataY_RegisterIndex) * 4;
         i2c.a_clk_reg = le16_to_cpu(gpio.usClkA_RegisterIndex) * 4;
         i2c.a_data_reg = le16_to_cpu(gpio.usDataA_RegisterIndex) * 4;
         i2c.mask_clk_mask = (1 << gpio.ucClkMaskShift);
         i2c.mask_data_mask = (1 << gpio.ucDataMaskShift);
-        i2c.put_clk_mask = (1 << gpio.ucClkEnShift);
-        i2c.put_data_mask = (1 << gpio.ucDataEnShift);
-        i2c.get_clk_mask = (1 << gpio.ucClkY_Shift);
-        i2c.get_data_mask = (1 << gpio.ucDataY_Shift);
+        i2c.en_clk_mask = (1 << gpio.ucClkEnShift);
+        i2c.en_data_mask = (1 << gpio.ucDataEnShift);
+        i2c.y_clk_mask = (1 << gpio.ucClkY_Shift);
+        i2c.y_data_mask = (1 << gpio.ucDataY_Shift);
         i2c.a_clk_mask = (1 << gpio.ucClkA_Shift);
         i2c.a_data_mask = (1 << gpio.ucDataA_Shift);
         i2c.valid = true;
diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index 5253cbf6db1..e2a51de67aa 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -450,29 +450,29 @@ struct radeon_i2c_bus_rec combios_setup_i2c_bus(int ddc_line)
         i2c.mask_data_mask = RADEON_GPIO_EN_0;
         i2c.a_clk_mask = RADEON_GPIO_A_1;
         i2c.a_data_mask = RADEON_GPIO_A_0;
-        i2c.put_clk_mask = RADEON_GPIO_EN_1;
-        i2c.put_data_mask = RADEON_GPIO_EN_0;
-        i2c.get_clk_mask = RADEON_GPIO_Y_1;
-        i2c.get_data_mask = RADEON_GPIO_Y_0;
+        i2c.en_clk_mask = RADEON_GPIO_EN_1;
+        i2c.en_data_mask = RADEON_GPIO_EN_0;
+        i2c.y_clk_mask = RADEON_GPIO_Y_1;
+        i2c.y_data_mask = RADEON_GPIO_Y_0;
         if ((ddc_line == RADEON_LCD_GPIO_MASK) ||
             (ddc_line == RADEON_MDGPIO_EN_REG)) {
                 i2c.mask_clk_reg = ddc_line;
                 i2c.mask_data_reg = ddc_line;
                 i2c.a_clk_reg = ddc_line;
                 i2c.a_data_reg = ddc_line;
-                i2c.put_clk_reg = ddc_line;
-                i2c.put_data_reg = ddc_line;
-                i2c.get_clk_reg = ddc_line + 4;
-                i2c.get_data_reg = ddc_line + 4;
+                i2c.en_clk_reg = ddc_line;
+                i2c.en_data_reg = ddc_line;
+                i2c.y_clk_reg = ddc_line + 4;
+                i2c.y_data_reg = ddc_line + 4;
         } else {
                 i2c.mask_clk_reg = ddc_line;
                 i2c.mask_data_reg = ddc_line;
                 i2c.a_clk_reg = ddc_line;
                 i2c.a_data_reg = ddc_line;
-                i2c.put_clk_reg = ddc_line;
-                i2c.put_data_reg = ddc_line;
-                i2c.get_clk_reg = ddc_line;
-                i2c.get_data_reg = ddc_line;
+                i2c.en_clk_reg = ddc_line;
+                i2c.en_data_reg = ddc_line;
+                i2c.y_clk_reg = ddc_line;
+                i2c.y_data_reg = ddc_line;
         }
 
         if (ddc_line)
@@ -1567,18 +1567,18 @@ static bool radeon_apply_legacy_quirks(struct drm_device *dev,
                 ddc_i2c->mask_data_mask = 0x80;
                 ddc_i2c->a_clk_mask = (0x20 << 8);
                 ddc_i2c->a_data_mask = 0x80;
-                ddc_i2c->put_clk_mask = (0x20 << 8);
-                ddc_i2c->put_data_mask = 0x80;
-                ddc_i2c->get_clk_mask = (0x20 << 8);
-                ddc_i2c->get_data_mask = 0x80;
+                ddc_i2c->en_clk_mask = (0x20 << 8);
+                ddc_i2c->en_data_mask = 0x80;
+                ddc_i2c->y_clk_mask = (0x20 << 8);
+                ddc_i2c->y_data_mask = 0x80;
                 ddc_i2c->mask_clk_reg = RADEON_GPIOPAD_MASK;
                 ddc_i2c->mask_data_reg = RADEON_GPIOPAD_MASK;
                 ddc_i2c->a_clk_reg = RADEON_GPIOPAD_A;
                 ddc_i2c->a_data_reg = RADEON_GPIOPAD_A;
-                ddc_i2c->put_clk_reg = RADEON_GPIOPAD_EN;
-                ddc_i2c->put_data_reg = RADEON_GPIOPAD_EN;
-                ddc_i2c->get_clk_reg = RADEON_LCD_GPIO_Y_REG;
-                ddc_i2c->get_data_reg = RADEON_LCD_GPIO_Y_REG;
+                ddc_i2c->en_clk_reg = RADEON_GPIOPAD_EN;
+                ddc_i2c->en_data_reg = RADEON_GPIOPAD_EN;
+                ddc_i2c->y_clk_reg = RADEON_LCD_GPIO_Y_REG;
+                ddc_i2c->y_data_reg = RADEON_LCD_GPIO_Y_REG;
         }
 
         /* Certain IBM chipset RN50s have a BIOS reporting two VGAs,
@@ -1939,13 +1939,13 @@ bool radeon_get_legacy_connector_info_from_bios(struct drm_device *dev)
                                             RBIOS32(lcd_ddc_info + 3);
                                         ddc_i2c.a_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
-                                        ddc_i2c.put_clk_mask =
+                                        ddc_i2c.en_clk_mask =
                                             RBIOS32(lcd_ddc_info + 3);
-                                        ddc_i2c.put_data_mask =
+                                        ddc_i2c.en_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
-                                        ddc_i2c.get_clk_mask =
+                                        ddc_i2c.y_clk_mask =
                                             RBIOS32(lcd_ddc_info + 3);
-                                        ddc_i2c.get_data_mask =
+                                        ddc_i2c.y_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
                                         break;
                                 case DDC_GPIO:
@@ -1960,13 +1960,13 @@ bool radeon_get_legacy_connector_info_from_bios(struct drm_device *dev)
                                             RBIOS32(lcd_ddc_info + 3);
                                         ddc_i2c.a_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
-                                        ddc_i2c.put_clk_mask =
+                                        ddc_i2c.en_clk_mask =
                                             RBIOS32(lcd_ddc_info + 3);
-                                        ddc_i2c.put_data_mask =
+                                        ddc_i2c.en_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
-                                        ddc_i2c.get_clk_mask =
+                                        ddc_i2c.y_clk_mask =
                                             RBIOS32(lcd_ddc_info + 3);
-                                        ddc_i2c.get_data_mask =
+                                        ddc_i2c.y_data_mask =
                                             RBIOS32(lcd_ddc_info + 7);
                                         break;
                                 default:
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index a3def191e98..8b117e82e5e 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -270,10 +270,10 @@ static void radeon_print_display_setup(struct drm_device *dev)
                                  radeon_connector->ddc_bus->rec.mask_data_reg,
                                  radeon_connector->ddc_bus->rec.a_clk_reg,
                                  radeon_connector->ddc_bus->rec.a_data_reg,
-                                 radeon_connector->ddc_bus->rec.put_clk_reg,
-                                 radeon_connector->ddc_bus->rec.put_data_reg,
-                                 radeon_connector->ddc_bus->rec.get_clk_reg,
-                                 radeon_connector->ddc_bus->rec.get_data_reg);
+                                 radeon_connector->ddc_bus->rec.en_clk_reg,
+                                 radeon_connector->ddc_bus->rec.en_data_reg,
+                                 radeon_connector->ddc_bus->rec.y_clk_reg,
+                                 radeon_connector->ddc_bus->rec.y_data_reg);
                 DRM_INFO("  Encoders:\n");
                 list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
                         radeon_encoder = to_radeon_encoder(encoder);
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index d8296acb082..e97a3912d99 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -78,16 +78,16 @@ void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
                                                 R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3)));
                 }
         }
-        if (lock_state) {
-                temp = RREG32(rec->a_clk_reg);
-                temp &= ~(rec->a_clk_mask);
-                WREG32(rec->a_clk_reg, temp);
-
-                temp = RREG32(rec->a_data_reg);
-                temp &= ~(rec->a_data_mask);
-                WREG32(rec->a_data_reg, temp);
-        }
 
+        /* clear the output pin values */
+        temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
+        WREG32(rec->a_clk_reg, temp);
+
+        temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
+        WREG32(rec->a_data_reg, temp);
+
+
+        /* mask the gpio pins for software use */
         temp = RREG32(rec->mask_clk_reg);
         if (lock_state)
                 temp |= rec->mask_clk_mask;
@@ -112,8 +112,9 @@ static int get_clock(void *i2c_priv)
         struct radeon_i2c_bus_rec *rec = &i2c->rec;
         uint32_t val;
 
-        val = RREG32(rec->get_clk_reg);
-        val &= rec->get_clk_mask;
+        /* read the value off the pin */
+        val = RREG32(rec->y_clk_reg);
+        val &= rec->y_clk_mask;
 
         return (val != 0);
 }
@@ -126,8 +127,10 @@ static int get_data(void *i2c_priv)
         struct radeon_i2c_bus_rec *rec = &i2c->rec;
         uint32_t val;
 
-        val = RREG32(rec->get_data_reg);
-        val &= rec->get_data_mask;
+        /* read the value off the pin */
+        val = RREG32(rec->y_data_reg);
+        val &= rec->y_data_mask;
+
         return (val != 0);
 }
 
@@ -138,9 +141,10 @@ static void set_clock(void *i2c_priv, int clock)
         struct radeon_i2c_bus_rec *rec = &i2c->rec;
         uint32_t val;
 
-        val = RREG32(rec->put_clk_reg) & (uint32_t)~(rec->put_clk_mask);
-        val |= clock ? 0 : rec->put_clk_mask;
-        WREG32(rec->put_clk_reg, val);
+        /* set pin direction */
+        val = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
+        val |= clock ? 0 : rec->en_clk_mask;
+        WREG32(rec->en_clk_reg, val);
 }
 
 static void set_data(void *i2c_priv, int data)
@@ -150,9 +154,10 @@ static void set_data(void *i2c_priv, int data)
         struct radeon_i2c_bus_rec *rec = &i2c->rec;
         uint32_t val;
 
-        val = RREG32(rec->put_data_reg) & (uint32_t)~(rec->put_data_mask);
-        val |= data ? 0 : rec->put_data_mask;
-        WREG32(rec->put_data_reg, val);
+        /* set pin direction */
+        val = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
+        val |= data ? 0 : rec->en_data_mask;
+        WREG32(rec->en_data_reg, val);
 }
 
 struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 491a1ec81a4..20847a2fc4d 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 {