diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 42b9e20782b0..45b93a096191 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1299,6 +1299,69 @@ static void intel_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe) POSTING_READ(reg); } +/* SBI access */ +static void +intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value) +{ + unsigned long flags; + + spin_lock_irqsave(&dev_priv->dpio_lock, flags); + if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_READY) == 0, + 100)) { + DRM_ERROR("timeout waiting for SBI to become ready\n"); + goto out_unlock; + } + + I915_WRITE(SBI_ADDR, + (reg << 16)); + I915_WRITE(SBI_DATA, + value); + I915_WRITE(SBI_CTL_STAT, + SBI_BUSY | + SBI_CTL_OP_CRWR); + + if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_READY | SBI_RESPONSE_SUCCESS)) == 0, + 100)) { + DRM_ERROR("timeout waiting for SBI to complete write transaction\n"); + goto out_unlock; + } + +out_unlock: + spin_unlock_irqrestore(&dev_priv->dpio_lock, flags); +} + +static u32 +intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg) +{ + unsigned long flags; + u32 value; + + spin_lock_irqsave(&dev_priv->dpio_lock, flags); + if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_READY) == 0, + 100)) { + DRM_ERROR("timeout waiting for SBI to become ready\n"); + goto out_unlock; + } + + I915_WRITE(SBI_ADDR, + (reg << 16)); + I915_WRITE(SBI_CTL_STAT, + SBI_BUSY | + SBI_CTL_OP_CRRD); + + if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_READY | SBI_RESPONSE_SUCCESS)) == 0, + 100)) { + DRM_ERROR("timeout waiting for SBI to complete read transaction\n"); + goto out_unlock; + } + + value = I915_READ(SBI_DATA); + +out_unlock: + spin_unlock_irqrestore(&dev_priv->dpio_lock, flags); + return value; +} + /** * intel_enable_pch_pll - enable PCH PLL * @dev_priv: i915 private structure |