drm/i915: base gmbus pin validity check on the gmbus pin map array

This will be helpful for adding future platforms. It is better to keep
the information in the single point of truth (the table) instead of
duplicating it into the validity function.

While at it, add dev_priv parameter to the function, also to prepare for
adding future platform support.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -3064,10 +3064,8 @@ void i915_teardown_sysfs(struct drm_device *dev_priv);
 /* intel_i2c.c */
 extern int intel_setup_gmbus(struct drm_device *dev);
 extern void intel_teardown_gmbus(struct drm_device *dev);
-static inline bool intel_gmbus_is_valid_pin(unsigned int pin)
-{
-	return (pin >= GMBUS_PIN_SSC && pin <= GMBUS_PIN_DPD);
-}
+extern bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
+				     unsigned int pin);
 
 extern struct i2c_adapter *
 intel_gmbus_get_adapter(struct drm_i915_private *dev_priv, unsigned int pin);

drivers/gpu/drm/i915/intel_bios.c

@@ -438,7 +438,7 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
 		if (block_size >= sizeof(*general)) {
 			int bus_pin = general->crt_ddc_gmbus_pin;
 			DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
-			if (intel_gmbus_is_valid_pin(bus_pin))
+			if (intel_gmbus_is_valid_pin(dev_priv, bus_pin))
 				dev_priv->vbt.crt_ddc_pin = bus_pin;
 		} else {
 			DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",

drivers/gpu/drm/i915/intel_dvo.c

@@ -502,7 +502,7 @@ void intel_dvo_init(struct drm_device *dev)
 		 * special cases, but otherwise default to what's defined
 		 * in the spec.
 		 */
-		if (intel_gmbus_is_valid_pin(dvo->gpio))
+		if (intel_gmbus_is_valid_pin(dev_priv, dvo->gpio))
 			gpio = dvo->gpio;
 		else if (dvo->type == INTEL_DVO_CHIP_LVDS)
 			gpio = GMBUS_PIN_SSC;

drivers/gpu/drm/i915/intel_i2c.c

@@ -49,6 +49,12 @@ static const struct gmbus_pin gmbus_pins[] = {
 	[GMBUS_PIN_DPD] = { "dpd", GPIOF },
 };
 
+bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
+			      unsigned int pin)
+{
+	return pin < ARRAY_SIZE(gmbus_pins) && gmbus_pins[pin].reg;
+}
+
 /* Intel GPIO access functions */
 
 #define I2C_RISEFALL_TIME 10
@@ -534,7 +540,7 @@ int intel_setup_gmbus(struct drm_device *dev)
 	init_waitqueue_head(&dev_priv->gmbus_wait_queue);
 
 	for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
-		if (!intel_gmbus_is_valid_pin(pin))
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
 			continue;
 
 		bus = &dev_priv->gmbus[pin];
@@ -571,7 +577,7 @@ int intel_setup_gmbus(struct drm_device *dev)
 
 err:
 	while (--pin) {
-		if (!intel_gmbus_is_valid_pin(pin))
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
 			continue;
 
 		bus = &dev_priv->gmbus[pin];
@@ -583,7 +589,7 @@ err:
 struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
 					    unsigned int pin)
 {
-	if (WARN_ON(!intel_gmbus_is_valid_pin(pin)))
+	if (WARN_ON(!intel_gmbus_is_valid_pin(dev_priv, pin)))
 		return NULL;
 
 	return &dev_priv->gmbus[pin].adapter;
@@ -613,7 +619,7 @@ void intel_teardown_gmbus(struct drm_device *dev)
 	unsigned int pin;
 
 	for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
-		if (!intel_gmbus_is_valid_pin(pin))
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
 			continue;
 
 		bus = &dev_priv->gmbus[pin];

drivers/gpu/drm/i915/intel_lvds.c

@@ -781,7 +781,7 @@ static bool lvds_is_present_in_vbt(struct drm_device *dev,
 		    child->device_type != DEVICE_TYPE_LFP)
 			continue;
 
-		if (intel_gmbus_is_valid_pin(child->i2c_pin))
+		if (intel_gmbus_is_valid_pin(dev_priv, child->i2c_pin))
 			*i2c_pin = child->i2c_pin;
 
 		/* However, we cannot trust the BIOS writers to populate

drivers/gpu/drm/i915/intel_sdvo.c

@@ -2291,7 +2291,8 @@ intel_sdvo_select_i2c_bus(struct drm_i915_private *dev_priv,
 	else
 		mapping = &dev_priv->sdvo_mappings[1];
 
-	if (mapping->initialized && intel_gmbus_is_valid_pin(mapping->i2c_pin))
+	if (mapping->initialized &&
+	    intel_gmbus_is_valid_pin(dev_priv, mapping->i2c_pin))
 		pin = mapping->i2c_pin;
 	else
 		pin = GMBUS_PIN_DPB;