1 files changed, 90 insertions, 28 deletions

diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index ae628001fd97..a64f26c670af 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -34,20 +34,71 @@
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
 
-struct gmbus_port {
+struct gmbus_pin {
 	const char *name;
 	int reg;
 };
 
-static const struct gmbus_port gmbus_ports[] = {
-	{ "ssc", GPIOB },
-	{ "vga", GPIOA },
-	{ "panel", GPIOC },
-	{ "dpc", GPIOD },
-	{ "dpb", GPIOE },
-	{ "dpd", GPIOF },
+/* Map gmbus pin pairs to names and registers. */
+static const struct gmbus_pin gmbus_pins[] = {
+	[GMBUS_PIN_SSC] = { "ssc", GPIOB },
+	[GMBUS_PIN_VGADDC] = { "vga", GPIOA },
+	[GMBUS_PIN_PANEL] = { "panel", GPIOC },
+	[GMBUS_PIN_DPC] = { "dpc", GPIOD },
+	[GMBUS_PIN_DPB] = { "dpb", GPIOE },
+	[GMBUS_PIN_DPD] = { "dpd", GPIOF },
 };
 
+static const struct gmbus_pin gmbus_pins_bdw[] = {
+	[GMBUS_PIN_VGADDC] = { "vga", GPIOA },
+	[GMBUS_PIN_DPC] = { "dpc", GPIOD },
+	[GMBUS_PIN_DPB] = { "dpb", GPIOE },
+	[GMBUS_PIN_DPD] = { "dpd", GPIOF },
+};
+
+static const struct gmbus_pin gmbus_pins_skl[] = {
+	[GMBUS_PIN_DPC] = { "dpc", GPIOD },
+	[GMBUS_PIN_DPB] = { "dpb", GPIOE },
+	[GMBUS_PIN_DPD] = { "dpd", GPIOF },
+};
+
+static const struct gmbus_pin gmbus_pins_bxt[] = {
+	[GMBUS_PIN_1_BXT] = { "dpb", PCH_GPIOB },
+	[GMBUS_PIN_2_BXT] = { "dpc", PCH_GPIOC },
+	[GMBUS_PIN_3_BXT] = { "misc", PCH_GPIOD },
+};
+
+/* pin is expected to be valid */
+static const struct gmbus_pin *get_gmbus_pin(struct drm_i915_private *dev_priv,
+					     unsigned int pin)
+{
+	if (IS_BROXTON(dev_priv))
+		return &gmbus_pins_bxt[pin];
+	else if (IS_SKYLAKE(dev_priv))
+		return &gmbus_pins_skl[pin];
+	else if (IS_BROADWELL(dev_priv))
+		return &gmbus_pins_bdw[pin];
+	else
+		return &gmbus_pins[pin];
+}
+
+bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
+			      unsigned int pin)
+{
+	unsigned int size;
+
+	if (IS_BROXTON(dev_priv))
+		size = ARRAY_SIZE(gmbus_pins_bxt);
+	else if (IS_SKYLAKE(dev_priv))
+		size = ARRAY_SIZE(gmbus_pins_skl);
+	else if (IS_BROADWELL(dev_priv))
+		size = ARRAY_SIZE(gmbus_pins_bdw);
+	else
+		size = ARRAY_SIZE(gmbus_pins);
+
+	return pin < size && get_gmbus_pin(dev_priv, pin)->reg;
+}
+
 /* Intel GPIO access functions */
 
 #define I2C_RISEFALL_TIME 10
@@ -182,15 +233,15 @@ intel_gpio_post_xfer(struct i2c_adapter *adapter)
 }
 
 static void
-intel_gpio_setup(struct intel_gmbus *bus, u32 pin)
+intel_gpio_setup(struct intel_gmbus *bus, unsigned int pin)
 {
 	struct drm_i915_private *dev_priv = bus->dev_priv;
 	struct i2c_algo_bit_data *algo;
 
 	algo = &bus->bit_algo;
 
-	/* -1 to map pin pair to gmbus index */
-	bus->gpio_reg = dev_priv->gpio_mmio_base + gmbus_ports[pin - 1].reg;
+	bus->gpio_reg = dev_priv->gpio_mmio_base +
+		get_gmbus_pin(dev_priv, pin)->reg;
 
 	bus->adapter.algo_data = algo;
 	algo->setsda = set_data;
@@ -577,7 +628,9 @@ static const struct i2c_algorithm gmbus_algorithm = {
 int intel_setup_gmbus(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	int ret, i;
+	struct intel_gmbus *bus;
+	unsigned int pin;
+	int ret;
 
 	if (HAS_PCH_NOP(dev))
 		return 0;
@@ -591,16 +644,18 @@ int intel_setup_gmbus(struct drm_device *dev)
 	mutex_init(&dev_priv->gmbus_mutex);
 	init_waitqueue_head(&dev_priv->gmbus_wait_queue);
 
-	for (i = 0; i < GMBUS_NUM_PORTS; i++) {
-		struct intel_gmbus *bus = &dev_priv->gmbus[i];
-		u32 port = i + 1; /* +1 to map gmbus index to pin pair */
+	for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
+			continue;
+
+		bus = &dev_priv->gmbus[pin];
 
 		bus->adapter.owner = THIS_MODULE;
 		bus->adapter.class = I2C_CLASS_DDC;
 		snprintf(bus->adapter.name,
 			 sizeof(bus->adapter.name),
 			 "i915 gmbus %s",
-			 gmbus_ports[i].name);
+			 get_gmbus_pin(dev_priv, pin)->name);
 
 		bus->adapter.dev.parent = &dev->pdev->dev;
 		bus->dev_priv = dev_priv;
@@ -608,13 +663,13 @@ int intel_setup_gmbus(struct drm_device *dev)
 		bus->adapter.algo = &gmbus_algorithm;
 
 		/* By default use a conservative clock rate */
-		bus->reg0 = port | GMBUS_RATE_100KHZ;
+		bus->reg0 = pin | GMBUS_RATE_100KHZ;
 
 		/* gmbus seems to be broken on i830 */
 		if (IS_I830(dev))
 			bus->force_bit = 1;
 
-		intel_gpio_setup(bus, port);
+		intel_gpio_setup(bus, pin);
 
 		ret = i2c_add_adapter(&bus->adapter);
 		if (ret)
@@ -626,20 +681,23 @@ int intel_setup_gmbus(struct drm_device *dev)
 	return 0;
 
 err:
-	while (--i) {
-		struct intel_gmbus *bus = &dev_priv->gmbus[i];
+	while (--pin) {
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
+			continue;
+
+		bus = &dev_priv->gmbus[pin];
 		i2c_del_adapter(&bus->adapter);
 	}
 	return ret;
 }
 
 struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
-					    unsigned port)
+					    unsigned int pin)
 {
-	WARN_ON(!intel_gmbus_is_port_valid(port));
-	/* -1 to map pin pair to gmbus index */
-	return (intel_gmbus_is_port_valid(port)) ?
-		&dev_priv->gmbus[port - 1].adapter : NULL;
+	if (WARN_ON(!intel_gmbus_is_valid_pin(dev_priv, pin)))
+		return NULL;
+
+	return &dev_priv->gmbus[pin].adapter;
 }
 
 void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
@@ -662,10 +720,14 @@ void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
 void intel_teardown_gmbus(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	int i;
+	struct intel_gmbus *bus;
+	unsigned int pin;
+
+	for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
+		if (!intel_gmbus_is_valid_pin(dev_priv, pin))
+			continue;
 
-	for (i = 0; i < GMBUS_NUM_PORTS; i++) {
-		struct intel_gmbus *bus = &dev_priv->gmbus[i];
+		bus = &dev_priv->gmbus[pin];
 		i2c_del_adapter(&bus->adapter);
 	}
 }