From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eugeni Dodonov Subject: [PATCH 03/25] drm/i915: add support for SBI ops Date: Wed, 9 May 2012 15:37:10 -0300 Message-ID: <1336588652-702-4-git-send-email-eugeni.dodonov@intel.com> References: <1336588652-702-1-git-send-email-eugeni.dodonov@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C4DF9F39C for ; Wed, 9 May 2012 11:37:54 -0700 (PDT) In-Reply-To: <1336588652-702-1-git-send-email-eugeni.dodonov@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org Cc: Eugeni Dodonov List-Id: intel-gfx@lists.freedesktop.org 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 Reviewed-by: Jesse Barnes Signed-off-by: Eugeni Dodonov --- drivers/gpu/drm/i915/intel_display.c | 63 ++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b322bde..e751081 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 -- 1.7.10