drm/i915: index gmbus tables using the pin pair number

Index the gmbus tables directly using the pin instead of having a
confusing "port = i + 1" mapping. This finishes off removing the "gmbus
port" as a notion, and leaves us with just the "gmbus pin".

As pin 0 is invalid by definition and the gmbus tables will have a gap
at that index, add pin validity check to all the loops. This will be
benefitial for supporting platforms that have different numbers of pins,
or gaps.

v2: s/GMBUS_PIN_MAX/GMBUS_NUM_PINS/ (Ville, Daniel)

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

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b0390c8c9595070f70cb9d9827dc18d26225369a..0ad11d9c123fc8bc00e28ccc6e9cfde57f492413 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1574,8 +1574,7 @@ struct drm_i915_private {
 
        struct i915_virtual_gpu vgpu;
 
-       struct intel_gmbus gmbus[GMBUS_NUM_PORTS];
-
+       struct intel_gmbus gmbus[GMBUS_NUM_PINS];
 
        /** gmbus_mutex protects against concurrent usage of the single hw gmbus
         * controller on different i2c buses. */

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b6113c9a803b02dd77114dc67ff9b0463897c9ab..49fbed9c35cd9471496a9336d8f0a527aa610467 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1797,7 +1797,7 @@ enum skl_disp_power_wells {
 #define   GMBUS_PIN_DPB                5 /* SDVO, HDMIB */
 #define   GMBUS_PIN_DPD                6 /* HDMID */
 #define   GMBUS_PIN_RESERVED   7 /* 7 reserved */
-#define   GMBUS_NUM_PORTS      (GMBUS_PIN_DPD - GMBUS_PIN_SSC + 1)
+#define   GMBUS_NUM_PINS       7 /* including 0 */
 #define GMBUS1                 0x5104 /* command/status */
 #define   GMBUS_SW_CLR_INT     (1<<31)
 #define   GMBUS_SW_RDY         (1<<30)

diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index b0003a2bd854b4d8520e3627a95862f203f684ff..ff47a8fdcb6d9a3562b42d99a7ec537774419c72 100644 (file)
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -34,18 +34,19 @@
 #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 },
 };
 
 /* Intel GPIO access functions */
@@ -182,15 +183,14 @@ 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 + gmbus_pins[pin].reg;
 
        bus->adapter.algo_data = algo;
        algo->setsda = set_data;
@@ -517,7 +517,9 @@ 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;
@@ -531,16 +533,18 @@ 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(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);
+                        gmbus_pins[pin].name);
 
                bus->adapter.dev.parent = &dev->pdev->dev;
                bus->dev_priv = dev_priv;
@@ -548,13 +552,13 @@ 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)
@@ -566,8 +570,11 @@ 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(pin))
+                       continue;
+
+               bus = &dev_priv->gmbus[pin];
                i2c_del_adapter(&bus->adapter);
        }
        return ret;
@@ -576,10 +583,10 @@ err:
 struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
                                            unsigned int pin)
 {
-       WARN_ON(!intel_gmbus_is_valid_pin(pin));
-       /* -1 to map pin pair to gmbus index */
-       return (intel_gmbus_is_valid_pin(pin)) ?
-               &dev_priv->gmbus[pin - 1].adapter : NULL;
+       if (WARN_ON(!intel_gmbus_is_valid_pin(pin)))
+               return NULL;
+
+       return &dev_priv->gmbus[pin].adapter;
 }
 
 void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
@@ -602,10 +609,14 @@ 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(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);
        }
 }