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path: root/drivers/gpu/drm/i915/intel_i2c.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c167
1 files changed, 141 insertions, 26 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 3ef5af15b81..d33b61d0dd3 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -34,6 +34,11 @@
#include <drm/i915_drm.h>
#include "i915_drv.h"
+enum disp_clk {
+ CDCLK,
+ CZCLK
+};
+
struct gmbus_port {
const char *name;
int reg;
@@ -58,11 +63,62 @@ to_intel_gmbus(struct i2c_adapter *i2c)
return container_of(i2c, struct intel_gmbus, adapter);
}
+static int get_disp_clk_div(struct drm_i915_private *dev_priv,
+ enum disp_clk clk)
+{
+ u32 reg_val;
+ int clk_ratio;
+
+ reg_val = I915_READ(CZCLK_CDCLK_FREQ_RATIO);
+
+ if (clk == CDCLK)
+ clk_ratio =
+ ((reg_val & CDCLK_FREQ_MASK) >> CDCLK_FREQ_SHIFT) + 1;
+ else
+ clk_ratio = (reg_val & CZCLK_FREQ_MASK) + 1;
+
+ return clk_ratio;
+}
+
+static void gmbus_set_freq(struct drm_i915_private *dev_priv)
+{
+ int vco, gmbus_freq = 0, cdclk_div;
+
+ BUG_ON(!IS_VALLEYVIEW(dev_priv->dev));
+
+ vco = valleyview_get_vco(dev_priv);
+
+ /* Get the CDCLK divide ratio */
+ cdclk_div = get_disp_clk_div(dev_priv, CDCLK);
+
+ /*
+ * Program the gmbus_freq based on the cdclk frequency.
+ * BSpec erroneously claims we should aim for 4MHz, but
+ * in fact 1MHz is the correct frequency.
+ */
+ if (cdclk_div)
+ gmbus_freq = (vco << 1) / cdclk_div;
+
+ if (WARN_ON(gmbus_freq == 0))
+ return;
+
+ I915_WRITE(GMBUSFREQ_VLV, gmbus_freq);
+}
+
void
intel_i2c_reset(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
+
+ /*
+ * In BIOS-less system, program the correct gmbus frequency
+ * before reading edid.
+ */
+ if (IS_VALLEYVIEW(dev))
+ gmbus_set_freq(dev_priv);
+
I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
+ I915_WRITE(dev_priv->gpio_mmio_base + GMBUS4, 0);
}
static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable)
@@ -203,6 +259,71 @@ intel_gpio_setup(struct intel_gmbus *bus, u32 pin)
}
static int
+gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
+ u32 gmbus2_status,
+ u32 gmbus4_irq_en)
+{
+ int i;
+ int reg_offset = dev_priv->gpio_mmio_base;
+ u32 gmbus2 = 0;
+ DEFINE_WAIT(wait);
+
+ if (!HAS_GMBUS_IRQ(dev_priv->dev))
+ gmbus4_irq_en = 0;
+
+ /* 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);
+
+ 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);
+ if (gmbus2 & (GMBUS_SATOER | gmbus2_status))
+ break;
+
+ schedule_timeout(1);
+ }
+ finish_wait(&dev_priv->gmbus_wait_queue, &wait);
+
+ I915_WRITE(GMBUS4 + reg_offset, 0);
+
+ if (gmbus2 & GMBUS_SATOER)
+ return -ENXIO;
+ if (gmbus2 & gmbus2_status)
+ return 0;
+ return -ETIMEDOUT;
+}
+
+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)
+
+ 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);
+
+ ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
+ msecs_to_jiffies_timeout(10));
+
+ I915_WRITE(GMBUS4 + reg_offset, 0);
+
+ if (ret)
+ return 0;
+ else
+ return -ETIMEDOUT;
+#undef C
+}
+
+static int
gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
u32 gmbus1_index)
{
@@ -219,15 +340,11 @@ gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
while (len) {
int ret;
u32 val, loop = 0;
- u32 gmbus2;
- ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
- (GMBUS_SATOER | GMBUS_HW_RDY),
- 50);
+ ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY,
+ GMBUS_HW_RDY_EN);
if (ret)
- return -ETIMEDOUT;
- if (gmbus2 & GMBUS_SATOER)
- return -ENXIO;
+ return ret;
val = I915_READ(GMBUS3 + reg_offset);
do {
@@ -261,7 +378,6 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
while (len) {
int ret;
- u32 gmbus2;
val = loop = 0;
do {
@@ -270,13 +386,10 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
I915_WRITE(GMBUS3 + reg_offset, val);
- ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
- (GMBUS_SATOER | GMBUS_HW_RDY),
- 50);
+ ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY,
+ GMBUS_HW_RDY_EN);
if (ret)
- return -ETIMEDOUT;
- if (gmbus2 & GMBUS_SATOER)
- return -ENXIO;
+ return ret;
}
return 0;
}
@@ -333,6 +446,7 @@ gmbus_xfer(struct i2c_adapter *adapter,
int i, reg_offset;
int ret = 0;
+ intel_aux_display_runtime_get(dev_priv);
mutex_lock(&dev_priv->gmbus_mutex);
if (bus->force_bit) {
@@ -345,8 +459,6 @@ gmbus_xfer(struct i2c_adapter *adapter,
I915_WRITE(GMBUS0 + reg_offset, bus->reg0);
for (i = 0; i < num; i++) {
- u32 gmbus2;
-
if (gmbus_is_index_read(msgs, i, num)) {
ret = gmbus_xfer_index_read(dev_priv, &msgs[i]);
i += 1; /* set i to the index of the read xfer */
@@ -361,13 +473,12 @@ gmbus_xfer(struct i2c_adapter *adapter,
if (ret == -ENXIO)
goto clear_err;
- ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) &
- (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE),
- 50);
+ ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_WAIT_PHASE,
+ GMBUS_HW_WAIT_EN);
+ if (ret == -ENXIO)
+ goto clear_err;
if (ret)
goto timeout;
- if (gmbus2 & GMBUS_SATOER)
- goto clear_err;
}
/* Generate a STOP condition on the bus. Note that gmbus can't generata
@@ -380,8 +491,7 @@ gmbus_xfer(struct i2c_adapter *adapter,
* We will re-enable it at the start of the next xfer,
* till then let it sleep.
*/
- if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0,
- 10)) {
+ if (gmbus_wait_idle(dev_priv)) {
DRM_DEBUG_KMS("GMBUS [%s] timed out waiting for idle\n",
adapter->name);
ret = -ETIMEDOUT;
@@ -405,8 +515,7 @@ clear_err:
* it's slow responding and only answers on the 2nd retry.
*/
ret = -ENXIO;
- if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0,
- 10)) {
+ if (gmbus_wait_idle(dev_priv)) {
DRM_DEBUG_KMS("GMBUS [%s] timed out after NAK\n",
adapter->name);
ret = -ETIMEDOUT;
@@ -437,6 +546,7 @@ timeout:
out:
mutex_unlock(&dev_priv->gmbus_mutex);
+ intel_aux_display_runtime_put(dev_priv);
return ret;
}
@@ -463,12 +573,17 @@ int intel_setup_gmbus(struct drm_device *dev)
struct drm_i915_private *dev_priv = dev->dev_private;
int ret, i;
- if (HAS_PCH_SPLIT(dev))
+ if (HAS_PCH_NOP(dev))
+ return 0;
+ else if (HAS_PCH_SPLIT(dev))
dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
+ else if (IS_VALLEYVIEW(dev))
+ dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE;
else
dev_priv->gpio_mmio_base = 0;
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];
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:18:34 +0000