diff mbox

[25/43] drm/i915: Include gpio_mmio_base in GMBUS reg defines

Message ID 1442595836-23981-26-git-send-email-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ville Syrjala Sept. 18, 2015, 5:03 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  | 12 ++++-----
 drivers/gpu/drm/i915/intel_i2c.c | 54 +++++++++++++++++-----------------------
 2 files changed, 29 insertions(+), 37 deletions(-)

Comments

Jesse Barnes Oct. 12, 2015, 3:56 p.m. UTC | #1 
On 09/18/2015 10:03 AM, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  | 12 ++++-----
>  drivers/gpu/drm/i915/intel_i2c.c | 54 +++++++++++++++++-----------------------
>  2 files changed, 29 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index b35e24f..0216771 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2114,7 +2114,7 @@ enum skl_disp_power_wells {
>  # define GPIO_DATA_VAL_IN		(1 << 12)
>  # define GPIO_DATA_PULLUP_DISABLE	(1 << 13)
>  
> -#define GMBUS0			0x5100 /* clock/port select */
> +#define GMBUS0			(dev_priv->gpio_mmio_base + 0x5100) /* clock/port select */
>  #define   GMBUS_RATE_100KHZ	(0<<8)
>  #define   GMBUS_RATE_50KHZ	(1<<8)
>  #define   GMBUS_RATE_400KHZ	(2<<8) /* reserved on Pineview */
> @@ -2133,7 +2133,7 @@ enum skl_disp_power_wells {
>  #define   GMBUS_PIN_2_BXT	2
>  #define   GMBUS_PIN_3_BXT	3
>  #define   GMBUS_NUM_PINS	7 /* including 0 */
> -#define GMBUS1			0x5104 /* command/status */
> +#define GMBUS1			(dev_priv->gpio_mmio_base + 0x5104) /* command/status */
>  #define   GMBUS_SW_CLR_INT	(1<<31)
>  #define   GMBUS_SW_RDY		(1<<30)
>  #define   GMBUS_ENT		(1<<29) /* enable timeout */
> @@ -2147,7 +2147,7 @@ enum skl_disp_power_wells {
>  #define   GMBUS_SLAVE_ADDR_SHIFT 1
>  #define   GMBUS_SLAVE_READ	(1<<0)
>  #define   GMBUS_SLAVE_WRITE	(0<<0)
> -#define GMBUS2			0x5108 /* status */
> +#define GMBUS2			(dev_priv->gpio_mmio_base + 0x5108) /* status */
>  #define   GMBUS_INUSE		(1<<15)
>  #define   GMBUS_HW_WAIT_PHASE	(1<<14)
>  #define   GMBUS_STALL_TIMEOUT	(1<<13)
> @@ -2155,14 +2155,14 @@ enum skl_disp_power_wells {
>  #define   GMBUS_HW_RDY		(1<<11)
>  #define   GMBUS_SATOER		(1<<10)
>  #define   GMBUS_ACTIVE		(1<<9)
> -#define GMBUS3			0x510c /* data buffer bytes 3-0 */
> -#define GMBUS4			0x5110 /* interrupt mask (Pineview+) */
> +#define GMBUS3			(dev_priv->gpio_mmio_base + 0x510c) /* data buffer bytes 3-0 */
> +#define GMBUS4			(dev_priv->gpio_mmio_base + 0x5110) /* interrupt mask (Pineview+) */
>  #define   GMBUS_SLAVE_TIMEOUT_EN (1<<4)
>  #define   GMBUS_NAK_EN		(1<<3)
>  #define   GMBUS_IDLE_EN		(1<<2)
>  #define   GMBUS_HW_WAIT_EN	(1<<1)
>  #define   GMBUS_HW_RDY_EN	(1<<0)
> -#define GMBUS5			0x5120 /* byte index */
> +#define GMBUS5			(dev_priv->gpio_mmio_base + 0x5120) /* byte index */
>  #define   GMBUS_2BYTE_INDEX_EN	(1<<31)
>  
>  /*
> diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
> index a64f26c..1369fc4 100644
> --- a/drivers/gpu/drm/i915/intel_i2c.c
> +++ b/drivers/gpu/drm/i915/intel_i2c.c
> @@ -114,8 +114,8 @@ intel_i2c_reset(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
> -	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS4, 0);
> +	I915_WRITE(GMBUS0, 0);
> +	I915_WRITE(GMBUS4, 0);
>  }
>  
>  static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable)
> @@ -261,7 +261,6 @@ gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
>  		     u32 gmbus4_irq_en)
>  {
>  	int i;
> -	int reg_offset = dev_priv->gpio_mmio_base;
>  	u32 gmbus2 = 0;
>  	DEFINE_WAIT(wait);
>  
> @@ -271,13 +270,13 @@ gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
>  	/* Important: The hw handles only the first bit, so set only one! Since
>  	 * we also need to check for NAKs besides the hw ready/idle signal, we
>  	 * need to wake up periodically and check that ourselves. */
> -	I915_WRITE(GMBUS4 + reg_offset, gmbus4_irq_en);
> +	I915_WRITE(GMBUS4, gmbus4_irq_en);
>  
>  	for (i = 0; i < msecs_to_jiffies_timeout(50); i++) {
>  		prepare_to_wait(&dev_priv->gmbus_wait_queue, &wait,
>  				TASK_UNINTERRUPTIBLE);
>  
> -		gmbus2 = I915_READ_NOTRACE(GMBUS2 + reg_offset);
> +		gmbus2 = I915_READ_NOTRACE(GMBUS2);
>  		if (gmbus2 & (GMBUS_SATOER | gmbus2_status))
>  			break;
>  
> @@ -285,7 +284,7 @@ gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
>  	}
>  	finish_wait(&dev_priv->gmbus_wait_queue, &wait);
>  
> -	I915_WRITE(GMBUS4 + reg_offset, 0);
> +	I915_WRITE(GMBUS4, 0);
>  
>  	if (gmbus2 & GMBUS_SATOER)
>  		return -ENXIO;
> @@ -298,20 +297,19 @@ static int
>  gmbus_wait_idle(struct drm_i915_private *dev_priv)
>  {
>  	int ret;
> -	int reg_offset = dev_priv->gpio_mmio_base;
>  
> -#define C ((I915_READ_NOTRACE(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0)
> +#define C ((I915_READ_NOTRACE(GMBUS2) & GMBUS_ACTIVE) == 0)
>  
>  	if (!HAS_GMBUS_IRQ(dev_priv->dev))
>  		return wait_for(C, 10);
>  
>  	/* Important: The hw handles only the first bit, so set only one! */
> -	I915_WRITE(GMBUS4 + reg_offset, GMBUS_IDLE_EN);
> +	I915_WRITE(GMBUS4, GMBUS_IDLE_EN);
>  
>  	ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
>  				 msecs_to_jiffies_timeout(10));
>  
> -	I915_WRITE(GMBUS4 + reg_offset, 0);
> +	I915_WRITE(GMBUS4, 0);
>  
>  	if (ret)
>  		return 0;
> @@ -325,9 +323,7 @@ gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
>  		      unsigned short addr, u8 *buf, unsigned int len,
>  		      u32 gmbus1_index)
>  {
> -	int reg_offset = dev_priv->gpio_mmio_base;
> -
> -	I915_WRITE(GMBUS1 + reg_offset,
> +	I915_WRITE(GMBUS1,
>  		   gmbus1_index |
>  		   GMBUS_CYCLE_WAIT |
>  		   (len << GMBUS_BYTE_COUNT_SHIFT) |
> @@ -342,7 +338,7 @@ gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
>  		if (ret)
>  			return ret;
>  
> -		val = I915_READ(GMBUS3 + reg_offset);
> +		val = I915_READ(GMBUS3);
>  		do {
>  			*buf++ = val & 0xff;
>  			val >>= 8;
> @@ -380,7 +376,6 @@ static int
>  gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
>  		       unsigned short addr, u8 *buf, unsigned int len)
>  {
> -	int reg_offset = dev_priv->gpio_mmio_base;
>  	unsigned int chunk_size = len;
>  	u32 val, loop;
>  
> @@ -390,8 +385,8 @@ gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
>  		len -= 1;
>  	}
>  
> -	I915_WRITE(GMBUS3 + reg_offset, val);
> -	I915_WRITE(GMBUS1 + reg_offset,
> +	I915_WRITE(GMBUS3, val);
> +	I915_WRITE(GMBUS1,
>  		   GMBUS_CYCLE_WAIT |
>  		   (chunk_size << GMBUS_BYTE_COUNT_SHIFT) |
>  		   (addr << GMBUS_SLAVE_ADDR_SHIFT) |
> @@ -404,7 +399,7 @@ gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
>  			val |= *buf++ << (8 * loop);
>  		} while (--len && ++loop < 4);
>  
> -		I915_WRITE(GMBUS3 + reg_offset, val);
> +		I915_WRITE(GMBUS3, val);
>  
>  		ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY,
>  					   GMBUS_HW_RDY_EN);
> @@ -452,7 +447,6 @@ gmbus_is_index_read(struct i2c_msg *msgs, int i, int num)
>  static int
>  gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct i2c_msg *msgs)
>  {
> -	int reg_offset = dev_priv->gpio_mmio_base;
>  	u32 gmbus1_index = 0;
>  	u32 gmbus5 = 0;
>  	int ret;
> @@ -466,13 +460,13 @@ gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct i2c_msg *msgs)
>  
>  	/* GMBUS5 holds 16-bit index */
>  	if (gmbus5)
> -		I915_WRITE(GMBUS5 + reg_offset, gmbus5);
> +		I915_WRITE(GMBUS5, gmbus5);
>  
>  	ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus1_index);
>  
>  	/* Clear GMBUS5 after each index transfer */
>  	if (gmbus5)
> -		I915_WRITE(GMBUS5 + reg_offset, 0);
> +		I915_WRITE(GMBUS5, 0);
>  
>  	return ret;
>  }
> @@ -486,7 +480,7 @@ gmbus_xfer(struct i2c_adapter *adapter,
>  					       struct intel_gmbus,
>  					       adapter);
>  	struct drm_i915_private *dev_priv = bus->dev_priv;
> -	int i = 0, inc, try = 0, reg_offset;
> +	int i = 0, inc, try = 0;
>  	int ret = 0;
>  
>  	intel_aux_display_runtime_get(dev_priv);
> @@ -497,10 +491,8 @@ gmbus_xfer(struct i2c_adapter *adapter,
>  		goto out;
>  	}
>  
> -	reg_offset = dev_priv->gpio_mmio_base;
> -
>  retry:
> -	I915_WRITE(GMBUS0 + reg_offset, bus->reg0);
> +	I915_WRITE(GMBUS0, bus->reg0);
>  
>  	for (; i < num; i += inc) {
>  		inc = 1;
> @@ -530,7 +522,7 @@ retry:
>  	 * a STOP on the very first cycle. To simplify the code we
>  	 * unconditionally generate the STOP condition with an additional gmbus
>  	 * cycle. */
> -	I915_WRITE(GMBUS1 + reg_offset, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
> +	I915_WRITE(GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
>  
>  	/* Mark the GMBUS interface as disabled after waiting for idle.
>  	 * We will re-enable it at the start of the next xfer,
> @@ -541,7 +533,7 @@ retry:
>  			 adapter->name);
>  		ret = -ETIMEDOUT;
>  	}
> -	I915_WRITE(GMBUS0 + reg_offset, 0);
> +	I915_WRITE(GMBUS0, 0);
>  	ret = ret ?: i;
>  	goto out;
>  
> @@ -570,9 +562,9 @@ clear_err:
>  	 * of resetting the GMBUS controller and so clearing the
>  	 * BUS_ERROR raised by the slave's NAK.
>  	 */
> -	I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
> -	I915_WRITE(GMBUS1 + reg_offset, 0);
> -	I915_WRITE(GMBUS0 + reg_offset, 0);
> +	I915_WRITE(GMBUS1, GMBUS_SW_CLR_INT);
> +	I915_WRITE(GMBUS1, 0);
> +	I915_WRITE(GMBUS0, 0);
>  
>  	DRM_DEBUG_KMS("GMBUS [%s] NAK for addr: %04x %c(%d)\n",
>  			 adapter->name, msgs[i].addr,
> @@ -595,7 +587,7 @@ clear_err:
>  timeout:
>  	DRM_INFO("GMBUS [%s] timed out, falling back to bit banging on pin %d\n",
>  		 bus->adapter.name, bus->reg0 & 0xff);
> -	I915_WRITE(GMBUS0 + reg_offset, 0);
> +	I915_WRITE(GMBUS0, 0);
>  
>  	/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
>  	bus->force_bit = 1;
> 

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b35e24f..0216771 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2114,7 +2114,7 @@  enum skl_disp_power_wells {
 # define GPIO_DATA_VAL_IN		(1 << 12)
 # define GPIO_DATA_PULLUP_DISABLE	(1 << 13)
 
-#define GMBUS0			0x5100 /* clock/port select */
+#define GMBUS0			(dev_priv->gpio_mmio_base + 0x5100) /* clock/port select */
 #define   GMBUS_RATE_100KHZ	(0<<8)
 #define   GMBUS_RATE_50KHZ	(1<<8)
 #define   GMBUS_RATE_400KHZ	(2<<8) /* reserved on Pineview */
@@ -2133,7 +2133,7 @@  enum skl_disp_power_wells {
 #define   GMBUS_PIN_2_BXT	2
 #define   GMBUS_PIN_3_BXT	3
 #define   GMBUS_NUM_PINS	7 /* including 0 */
-#define GMBUS1			0x5104 /* command/status */
+#define GMBUS1			(dev_priv->gpio_mmio_base + 0x5104) /* command/status */
 #define   GMBUS_SW_CLR_INT	(1<<31)
 #define   GMBUS_SW_RDY		(1<<30)
 #define   GMBUS_ENT		(1<<29) /* enable timeout */
@@ -2147,7 +2147,7 @@  enum skl_disp_power_wells {
 #define   GMBUS_SLAVE_ADDR_SHIFT 1
 #define   GMBUS_SLAVE_READ	(1<<0)
 #define   GMBUS_SLAVE_WRITE	(0<<0)
-#define GMBUS2			0x5108 /* status */
+#define GMBUS2			(dev_priv->gpio_mmio_base + 0x5108) /* status */
 #define   GMBUS_INUSE		(1<<15)
 #define   GMBUS_HW_WAIT_PHASE	(1<<14)
 #define   GMBUS_STALL_TIMEOUT	(1<<13)
@@ -2155,14 +2155,14 @@  enum skl_disp_power_wells {
 #define   GMBUS_HW_RDY		(1<<11)
 #define   GMBUS_SATOER		(1<<10)
 #define   GMBUS_ACTIVE		(1<<9)
-#define GMBUS3			0x510c /* data buffer bytes 3-0 */
-#define GMBUS4			0x5110 /* interrupt mask (Pineview+) */
+#define GMBUS3			(dev_priv->gpio_mmio_base + 0x510c) /* data buffer bytes 3-0 */
+#define GMBUS4			(dev_priv->gpio_mmio_base + 0x5110) /* interrupt mask (Pineview+) */
 #define   GMBUS_SLAVE_TIMEOUT_EN (1<<4)
 #define   GMBUS_NAK_EN		(1<<3)
 #define   GMBUS_IDLE_EN		(1<<2)
 #define   GMBUS_HW_WAIT_EN	(1<<1)
 #define   GMBUS_HW_RDY_EN	(1<<0)
-#define GMBUS5			0x5120 /* byte index */
+#define GMBUS5			(dev_priv->gpio_mmio_base + 0x5120) /* byte index */
 #define   GMBUS_2BYTE_INDEX_EN	(1<<31)
 
 /*
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index a64f26c..1369fc4 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -114,8 +114,8 @@  intel_i2c_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
-	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS4, 0);
+	I915_WRITE(GMBUS0, 0);
+	I915_WRITE(GMBUS4, 0);
 }
 
 static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable)
@@ -261,7 +261,6 @@  gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
 		     u32 gmbus4_irq_en)
 {
 	int i;
-	int reg_offset = dev_priv->gpio_mmio_base;
 	u32 gmbus2 = 0;
 	DEFINE_WAIT(wait);
 
@@ -271,13 +270,13 @@  gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
 	/* Important: The hw handles only the first bit, so set only one! Since
 	 * we also need to check for NAKs besides the hw ready/idle signal, we
 	 * need to wake up periodically and check that ourselves. */
-	I915_WRITE(GMBUS4 + reg_offset, gmbus4_irq_en);
+	I915_WRITE(GMBUS4, gmbus4_irq_en);
 
 	for (i = 0; i < msecs_to_jiffies_timeout(50); i++) {
 		prepare_to_wait(&dev_priv->gmbus_wait_queue, &wait,
 				TASK_UNINTERRUPTIBLE);
 
-		gmbus2 = I915_READ_NOTRACE(GMBUS2 + reg_offset);
+		gmbus2 = I915_READ_NOTRACE(GMBUS2);
 		if (gmbus2 & (GMBUS_SATOER | gmbus2_status))
 			break;
 
@@ -285,7 +284,7 @@  gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
 	}
 	finish_wait(&dev_priv->gmbus_wait_queue, &wait);
 
-	I915_WRITE(GMBUS4 + reg_offset, 0);
+	I915_WRITE(GMBUS4, 0);
 
 	if (gmbus2 & GMBUS_SATOER)
 		return -ENXIO;
@@ -298,20 +297,19 @@  static int
 gmbus_wait_idle(struct drm_i915_private *dev_priv)
 {
 	int ret;
-	int reg_offset = dev_priv->gpio_mmio_base;
 
-#define C ((I915_READ_NOTRACE(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0)
+#define C ((I915_READ_NOTRACE(GMBUS2) & GMBUS_ACTIVE) == 0)
 
 	if (!HAS_GMBUS_IRQ(dev_priv->dev))
 		return wait_for(C, 10);
 
 	/* Important: The hw handles only the first bit, so set only one! */
-	I915_WRITE(GMBUS4 + reg_offset, GMBUS_IDLE_EN);
+	I915_WRITE(GMBUS4, GMBUS_IDLE_EN);
 
 	ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
 				 msecs_to_jiffies_timeout(10));
 
-	I915_WRITE(GMBUS4 + reg_offset, 0);
+	I915_WRITE(GMBUS4, 0);
 
 	if (ret)
 		return 0;
@@ -325,9 +323,7 @@  gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
 		      unsigned short addr, u8 *buf, unsigned int len,
 		      u32 gmbus1_index)
 {
-	int reg_offset = dev_priv->gpio_mmio_base;
-
-	I915_WRITE(GMBUS1 + reg_offset,
+	I915_WRITE(GMBUS1,
 		   gmbus1_index |
 		   GMBUS_CYCLE_WAIT |
 		   (len << GMBUS_BYTE_COUNT_SHIFT) |
@@ -342,7 +338,7 @@  gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
 		if (ret)
 			return ret;
 
-		val = I915_READ(GMBUS3 + reg_offset);
+		val = I915_READ(GMBUS3);
 		do {
 			*buf++ = val & 0xff;
 			val >>= 8;
@@ -380,7 +376,6 @@  static int
 gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
 		       unsigned short addr, u8 *buf, unsigned int len)
 {
-	int reg_offset = dev_priv->gpio_mmio_base;
 	unsigned int chunk_size = len;
 	u32 val, loop;
 
@@ -390,8 +385,8 @@  gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
 		len -= 1;
 	}
 
-	I915_WRITE(GMBUS3 + reg_offset, val);
-	I915_WRITE(GMBUS1 + reg_offset,
+	I915_WRITE(GMBUS3, val);
+	I915_WRITE(GMBUS1,
 		   GMBUS_CYCLE_WAIT |
 		   (chunk_size << GMBUS_BYTE_COUNT_SHIFT) |
 		   (addr << GMBUS_SLAVE_ADDR_SHIFT) |
@@ -404,7 +399,7 @@  gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
 			val |= *buf++ << (8 * loop);
 		} while (--len && ++loop < 4);
 
-		I915_WRITE(GMBUS3 + reg_offset, val);
+		I915_WRITE(GMBUS3, val);
 
 		ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY,
 					   GMBUS_HW_RDY_EN);
@@ -452,7 +447,6 @@  gmbus_is_index_read(struct i2c_msg *msgs, int i, int num)
 static int
 gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct i2c_msg *msgs)
 {
-	int reg_offset = dev_priv->gpio_mmio_base;
 	u32 gmbus1_index = 0;
 	u32 gmbus5 = 0;
 	int ret;
@@ -466,13 +460,13 @@  gmbus_xfer_index_read(struct drm_i915_private *dev_priv, struct i2c_msg *msgs)
 
 	/* GMBUS5 holds 16-bit index */
 	if (gmbus5)
-		I915_WRITE(GMBUS5 + reg_offset, gmbus5);
+		I915_WRITE(GMBUS5, gmbus5);
 
 	ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus1_index);
 
 	/* Clear GMBUS5 after each index transfer */
 	if (gmbus5)
-		I915_WRITE(GMBUS5 + reg_offset, 0);
+		I915_WRITE(GMBUS5, 0);
 
 	return ret;
 }
@@ -486,7 +480,7 @@  gmbus_xfer(struct i2c_adapter *adapter,
 					       struct intel_gmbus,
 					       adapter);
 	struct drm_i915_private *dev_priv = bus->dev_priv;
-	int i = 0, inc, try = 0, reg_offset;
+	int i = 0, inc, try = 0;
 	int ret = 0;
 
 	intel_aux_display_runtime_get(dev_priv);
@@ -497,10 +491,8 @@  gmbus_xfer(struct i2c_adapter *adapter,
 		goto out;
 	}
 
-	reg_offset = dev_priv->gpio_mmio_base;
-
 retry:
-	I915_WRITE(GMBUS0 + reg_offset, bus->reg0);
+	I915_WRITE(GMBUS0, bus->reg0);
 
 	for (; i < num; i += inc) {
 		inc = 1;
@@ -530,7 +522,7 @@  retry:
 	 * a STOP on the very first cycle. To simplify the code we
 	 * unconditionally generate the STOP condition with an additional gmbus
 	 * cycle. */
-	I915_WRITE(GMBUS1 + reg_offset, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
+	I915_WRITE(GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
 
 	/* Mark the GMBUS interface as disabled after waiting for idle.
 	 * We will re-enable it at the start of the next xfer,
@@ -541,7 +533,7 @@  retry:
 			 adapter->name);
 		ret = -ETIMEDOUT;
 	}
-	I915_WRITE(GMBUS0 + reg_offset, 0);
+	I915_WRITE(GMBUS0, 0);
 	ret = ret ?: i;
 	goto out;
 
@@ -570,9 +562,9 @@  clear_err:
 	 * of resetting the GMBUS controller and so clearing the
 	 * BUS_ERROR raised by the slave's NAK.
 	 */
-	I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
-	I915_WRITE(GMBUS1 + reg_offset, 0);
-	I915_WRITE(GMBUS0 + reg_offset, 0);
+	I915_WRITE(GMBUS1, GMBUS_SW_CLR_INT);
+	I915_WRITE(GMBUS1, 0);
+	I915_WRITE(GMBUS0, 0);
 
 	DRM_DEBUG_KMS("GMBUS [%s] NAK for addr: %04x %c(%d)\n",
 			 adapter->name, msgs[i].addr,
@@ -595,7 +587,7 @@  clear_err:
 timeout:
 	DRM_INFO("GMBUS [%s] timed out, falling back to bit banging on pin %d\n",
 		 bus->adapter.name, bus->reg0 & 0xff);
-	I915_WRITE(GMBUS0 + reg_offset, 0);
+	I915_WRITE(GMBUS0, 0);
 
 	/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
 	bus->force_bit = 1;