diff options
| author | Eugeni Dodonov <eugeni.dodonov@intel.com> | 2012-05-09 15:37:10 -0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-05-19 22:39:43 +0200 |
| commit | a416edefbbaf942b588595ad6fa63ac700f5d73c (patch) | |
| tree | 12becbc853c7725d0fee3dbe2212e269e10226ed | |
| parent | 7d4e146f7509b872fbcfbbbb39476eb9afaf2ba2 (diff) | |
drm/i915: add support for SBI ops
With Lynx Point, we need to use SBI to communicate with the display clock
control. This commit adds helper functions to access the registers via
SBI.
v2: de-inline the function and address changes in bits names
v3: protect operations with dpio_lock, increase timeout to 100 for
paranoia sake.
v4: decrease paranoia a bit, as noticed by Chris Wilson
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| -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 42b9e20782b..45b93a09619 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 |