[PATCH 08/26] drm/i915: add DPIO read/write functions for ValleyView

[Jesse Barnes <jbarnes@virtuousgeek.org>]

ValleyView and similar hardware (like CedarView) put some display
related registers like the PLL controls and dividers on a DPIO bus.  Add
simple indirect register access routines to get to those registers.

v2: move new wait_for macro to intel_drv.h (Ben)
    fix DPIO_PKT double write (Ben)
    add debugfs file

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_debugfs.c  |   48 ++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.h      |    4 ++
 drivers/gpu/drm/i915/i915_reg.h      |   55 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_display.c |   61 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h     |   14 ++++++++
 5 files changed, 182 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index fdb7cce..5693de1 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1502,6 +1502,53 @@ static int i915_ppgtt_info(struct seq_file *m, void *data)
 	return 0;
 }
 
+static int i915_dpio_info(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int ret;
+
+
+	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
+	if (ret)
+		return ret;
+
+	if (!IS_VALLEYVIEW(dev)) {
+		seq_printf(m, "unsupported\n");
+		return 0;
+	}
+
+	seq_printf(m, "DPIO_CTL: 0x%08x\n", I915_READ(DPIO_CTL));
+
+	seq_printf(m, "DPIO_DIV_A: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_DIV_A));
+	seq_printf(m, "DPIO_DIV_B: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_DIV_B));
+
+	seq_printf(m, "DPIO_REFSFR_A: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_REFSFR_A));
+	seq_printf(m, "DPIO_REFSFR_B: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_REFSFR_B));
+
+	seq_printf(m, "DPIO_CORE_CLK_A: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_CORE_CLK_A));
+	seq_printf(m, "DPIO_CORE_CLK_B: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_CORE_CLK_B));
+
+	seq_printf(m, "DPIO_LFP_COEFF_A: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_LFP_COEFF_A));
+	seq_printf(m, "DPIO_LFP_COEFF_B: 0x%08x\n",
+		   intel_dpio_read(dev_priv, _DPIO_LFP_COEFF_B));
+
+	seq_printf(m, "DPIO_FASTCLK_DISABLE: 0x%08x\n",
+		   intel_dpio_read(dev_priv, DPIO_FASTCLK_DISABLE));
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return 0;
+}
+
 static int
 i915_debugfs_common_open(struct inode *inode,
 			 struct file *filp)
@@ -1844,6 +1891,7 @@ static struct drm_info_list i915_debugfs_list[] = {
 	{"i915_gen6_forcewake_count", i915_gen6_forcewake_count_info, 0},
 	{"i915_swizzle_info", i915_swizzle_info, 0},
 	{"i915_ppgtt_info", i915_ppgtt_info, 0},
+	{"i915_dpio", i915_dpio_info, 0},
 };
 #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cacc8d3..2b8b32d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -355,6 +355,10 @@ typedef struct drm_i915_private {
 
 	/* protects the irq masks */
 	spinlock_t irq_lock;
+
+	/* DPIO indirect register protection */
+	spinlock_t dpio_lock;
+
 	/** Cached value of IMR to avoid reads in updating the bitfield */
 	u32 pipestat[2];
 	u32 irq_mask;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 86de215..749e390 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -301,6 +301,61 @@
 #define  DEBUG_RESET_RENDER		(1<<8)
 #define  DEBUG_RESET_DISPLAY		(1<<9)
 
+/*
+ * DPIO - a special bus for various display related registers to hide behind:
+ *  0x800c: m1, m2, n, p1, p2, k dividers
+ *  0x8014: REF and SFR select
+ *  0x8014: N divider, VCO select
+ *  0x801c/3c: core clock bits
+ *  0x8048/68: low pass filter coefficients
+ *  0x8100: fast clock controls
+ */
+#define DPIO_PKT			0x2100
+#define  DPIO_RID			(0<<24)
+#define  DPIO_OP_WRITE			(1<<16)
+#define  DPIO_OP_READ			(0<<16)
+#define  DPIO_PORTID			(0x12<<8)
+#define  DPIO_BYTE			(0xf<<4)
+#define  DPIO_BUSY			(1<<0) /* status only */
+#define DPIO_DATA			0x2104
+#define DPIO_REG			0x2108
+#define DPIO_CTL			0x2110
+#define  DPIO_MODSEL1			(1<<3) /* if ref clk b == 27 */
+#define  DPIO_MODSEL0			(1<<2) /* if ref clk a == 27 */
+#define  DPIO_SFR_BYPASS		(1<<1)
+#define  DPIO_RESET			(1<<0)
+
+#define _DPIO_DIV_A			0x800c
+#define   DPIO_POST_DIV_SHIFT		(28) /* 3 bits */
+#define   DPIO_K_SHIFT			(24) /* 4 bits */
+#define   DPIO_P1_SHIFT			(21) /* 3 bits */
+#define   DPIO_P2_SHIFT			(16) /* 5 bits */
+#define   DPIO_N_SHIFT			(12) /* 4 bits */
+#define   DPIO_ENABLE_CALIBRATION	(1<<11)
+#define   DPIO_M1DIV_SHIFT		(8) /* 3 bits */
+#define   DPIO_M2DIV_MASK		0xff
+#define _DPIO_DIV_B			0x802c
+#define DPIO_DIV(pipe) _PIPE(pipe, _DPIO_DIV_A, _DPIO_DIV_B)
+
+#define _DPIO_REFSFR_A			0x8014
+#define   DPIO_REFSEL_OVERRIDE		27
+#define   DPIO_PLL_MODESEL_SHIFT	24 /* 3 bits */
+#define   DPIO_BIAS_CURRENT_CTL_SHIFT	21 /* 3 bits, always 0x7 */
+#define   DPIO_PLL_REFCLK_SEL_SHIFT	16 /* 2 bits */
+#define   DPIO_DRIVER_CTL_SHIFT		12 /* always set to 0x8 */
+#define   DPIO_CLK_BIAS_CTL_SHIFT	8 /* always set to 0x5 */
+#define _DPIO_REFSFR_B			0x8034
+#define DPIO_REFSFR(pipe) _PIPE(pipe, _DPIO_REFSFR_A, _DPIO_REFSFR_B)
+
+#define _DPIO_CORE_CLK_A		0x801c
+#define _DPIO_CORE_CLK_B		0x803c
+#define DPIO_CORE_CLK(pipe) _PIPE(pipe, _DPIO_CORE_CLK_A, _DPIO_CORE_CLK_B)
+
+#define _DPIO_LFP_COEFF_A		0x8048
+#define _DPIO_LFP_COEFF_B		0x8068
+#define DPIO_LFP_COEFF(pipe) _PIPE(pipe, _DPIO_LFP_COEFF_A, _DPIO_LFP_COEFF_B)
+
+#define DPIO_FASTCLK_DISABLE		0x8100
 
 /*
  * Fence registers
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 22619c6..f27728c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -360,6 +360,64 @@ static const intel_limit_t intel_limits_ironlake_display_port = {
 	.find_pll = intel_find_pll_ironlake_dp,
 };
 
+u32 intel_dpio_read(struct drm_i915_private *dev_priv, int reg)
+{
+	unsigned long flags;
+	u32 val = 0;
+
+	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
+	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
+		DRM_ERROR("DPIO idle wait timed out\n");
+		goto out_unlock;
+	}
+
+	I915_WRITE(DPIO_REG, reg);
+	I915_WRITE(DPIO_PKT, DPIO_RID | DPIO_OP_READ | DPIO_PORTID |
+		   DPIO_BYTE);
+	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
+		DRM_ERROR("DPIO read wait timed out\n");
+		goto out_unlock;
+	}
+	val = I915_READ(DPIO_DATA);
+
+out_unlock:
+	spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
+	return val;
+}
+
+static void intel_dpio_write(struct drm_i915_private *dev_priv, int reg,
+			     u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
+	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
+		DRM_ERROR("DPIO idle wait timed out\n");
+		goto out_unlock;
+	}
+
+	I915_WRITE(DPIO_DATA, val);
+	I915_WRITE(DPIO_REG, reg);
+	I915_WRITE(DPIO_PKT, DPIO_RID | DPIO_OP_WRITE | DPIO_PORTID |
+		   DPIO_BYTE);
+	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100))
+		DRM_ERROR("DPIO write wait timed out\n");
+
+out_unlock:
+	spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
+}
+
+static void vlv_init_dpio(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/* Reset the DPIO config */
+	I915_WRITE(DPIO_CTL, 0);
+	POSTING_READ(DPIO_CTL);
+	I915_WRITE(DPIO_CTL, 1);
+	POSTING_READ(DPIO_CTL);
+}
+
 static const intel_limit_t *intel_ironlake_limit(struct drm_crtc *crtc,
 						int refclk)
 {
@@ -9306,6 +9364,9 @@ void intel_modeset_cleanup(struct drm_device *dev)
 	if (IS_IRONLAKE_M(dev))
 		ironlake_disable_rc6(dev);
 
+	if (IS_VALLEYVIEW(dev))
+		vlv_init_dpio(dev);
+
 	mutex_unlock(&dev->struct_mutex);
 
 	/* Disable the irq before mode object teardown, for the irq might
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9cec6c3..07bcad0 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -45,6 +45,18 @@
 	ret__;								\
 })
 
+#define wait_for_atomic_us(COND, US) ({ \
+	int i, ret__ = -ETIMEDOUT;	\
+	for (i = 0; i < (US); i++) {	\
+		if ((COND)) {		\
+			ret__ = 0;	\
+			break;		\
+		}			\
+		udelay(1);		\
+	}				\
+	ret__;				\
+})
+
 #define wait_for(COND, MS) _wait_for(COND, MS, 1)
 #define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
 
@@ -419,4 +431,6 @@ extern int intel_sprite_set_colorkey(struct drm_device *dev, void *data,
 extern int intel_sprite_get_colorkey(struct drm_device *dev, void *data,
 				     struct drm_file *file_priv);
 
+extern u32 intel_dpio_read(struct drm_i915_private *dev_priv, int reg);
+
 #endif /* __INTEL_DRV_H__ */
-- 
1.7.5.4