[PATCH 3/5] drm/i915: index gmbus tables using the pin pair number

Jani Nikula
2015-03-26T22:21:48Z

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.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 3 +-
drivers/gpu/drm/i915/i915_reg.h | 2 +-
drivers/gpu/drm/i915/intel_i2c.c | 65 +++++++++++++++++++++++-----------------
3 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3ba5de19e039..0c6024101eb9 100644
--- 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_PIN_MAX];

/** 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 b6113c9a803b..cdc071cff001 100644
--- 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_PIN_MAX 7 /* not inclusive */
#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 b0003a2bd854..ff47a8fdcb6d 100644
--- 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);
}
}