drm: Add via unichrome support

Add DRM device driver for VIA Unichrome chipsets

From: Unichrome Project http://unichrome.sf.net, Erdi Chen, Thomas Hellstrom    Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/via_irq.c b/drivers/char/drm/via_irq.c
new file mode 100644
index 0000000..e8027f3
--- /dev/null
+++ b/drivers/char/drm/via_irq.c
@@ -0,0 +1,339 @@
+/* via_irq.c
+ *
+ * Copyright 2004 BEAM Ltd.
+ * Copyright 2002 Tungsten Graphics, Inc.
+ * Copyright 2005 Thomas Hellstrom.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BEAM LTD, TUNGSTEN GRAPHICS  AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Terry Barnaby <terry1@beam.ltd.uk>
+ *    Keith Whitwell <keith@tungstengraphics.com>
+ *    Thomas Hellstrom <unichrome@shipmail.org>
+ *
+ * This code provides standard DRM access to the Via Unichrome / Pro Vertical blank
+ * interrupt, as well as an infrastructure to handle other interrupts of the chip.
+ * The refresh rate is also calculated for video playback sync purposes.
+ */
+
+#include "drmP.h"
+#include "drm.h"
+#include "via_drm.h"
+#include "via_drv.h"
+
+#define VIA_REG_INTERRUPT       0x200
+
+/* VIA_REG_INTERRUPT */
+#define VIA_IRQ_GLOBAL          (1 << 31)
+#define VIA_IRQ_VBLANK_ENABLE   (1 << 19)
+#define VIA_IRQ_VBLANK_PENDING  (1 << 3)
+#define VIA_IRQ_HQV0_ENABLE     (1 << 11)
+#define VIA_IRQ_HQV1_ENABLE     (1 << 25)
+#define VIA_IRQ_HQV0_PENDING    (1 << 9)
+#define VIA_IRQ_HQV1_PENDING    (1 << 10)
+
+/*
+ * Device-specific IRQs go here. This type might need to be extended with
+ * the register if there are multiple IRQ control registers.
+ * Currently we activate the HQV interrupts of  Unichrome Pro group A. 
+ */
+
+static maskarray_t via_pro_group_a_irqs[] = {
+	{VIA_IRQ_HQV0_ENABLE, VIA_IRQ_HQV0_PENDING, 0x000003D0, 0x00008010, 0x00000000 },
+	{VIA_IRQ_HQV1_ENABLE, VIA_IRQ_HQV1_PENDING, 0x000013D0, 0x00008010, 0x00000000 }};
+static int via_num_pro_group_a = sizeof(via_pro_group_a_irqs)/sizeof(maskarray_t);
+
+static maskarray_t via_unichrome_irqs[] = {};
+static int via_num_unichrome = sizeof(via_unichrome_irqs)/sizeof(maskarray_t);
+
+
+static unsigned time_diff(struct timeval *now,struct timeval *then) 
+{
+    return (now->tv_usec >= then->tv_usec) ?
+        now->tv_usec - then->tv_usec :
+        1000000 - (then->tv_usec - now->tv_usec);
+}
+
+irqreturn_t via_driver_irq_handler(DRM_IRQ_ARGS)
+{
+	drm_device_t *dev = (drm_device_t *) arg;
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	u32 status;
+	int handled = 0;
+	struct timeval cur_vblank;
+	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
+	int i;
+
+	status = VIA_READ(VIA_REG_INTERRUPT);
+	if (status & VIA_IRQ_VBLANK_PENDING) {
+		atomic_inc(&dev->vbl_received);
+                if (!(atomic_read(&dev->vbl_received) & 0x0F)) {
+			do_gettimeofday(&cur_vblank);
+                        if (dev_priv->last_vblank_valid) {
+				dev_priv->usec_per_vblank = 
+					time_diff( &cur_vblank,&dev_priv->last_vblank) >> 4;
+			}
+			dev_priv->last_vblank = cur_vblank;
+			dev_priv->last_vblank_valid = 1;
+                }
+                if (!(atomic_read(&dev->vbl_received) & 0xFF)) {
+			DRM_DEBUG("US per vblank is: %u\n",
+				dev_priv->usec_per_vblank);
+		}
+		DRM_WAKEUP(&dev->vbl_queue);
+		drm_vbl_send_signals(dev);
+		handled = 1;
+	}
+	
+
+	for (i=0; i<dev_priv->num_irqs; ++i) {
+		if (status & cur_irq->pending_mask) {
+			atomic_inc( &cur_irq->irq_received );
+			DRM_WAKEUP( &cur_irq->irq_queue );
+			handled = 1;
+		}
+		cur_irq++;
+	}
+	
+	/* Acknowlege interrupts */
+	VIA_WRITE(VIA_REG_INTERRUPT, status);
+
+
+	if (handled)
+		return IRQ_HANDLED;
+	else
+		return IRQ_NONE;
+}
+
+static __inline__ void viadrv_acknowledge_irqs(drm_via_private_t * dev_priv)
+{
+	u32 status;
+
+	if (dev_priv) {
+		/* Acknowlege interrupts */
+		status = VIA_READ(VIA_REG_INTERRUPT);
+		VIA_WRITE(VIA_REG_INTERRUPT, status | 
+			  dev_priv->irq_pending_mask);
+	}
+}
+
+int via_driver_vblank_wait(drm_device_t * dev, unsigned int *sequence)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	unsigned int cur_vblank;
+	int ret = 0;
+
+	DRM_DEBUG("viadrv_vblank_wait\n");
+	if (!dev_priv) {
+		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
+		return -EINVAL;
+	}
+
+	viadrv_acknowledge_irqs(dev_priv);
+
+	/* Assume that the user has missed the current sequence number
+	 * by about a day rather than she wants to wait for years
+	 * using vertical blanks...
+	 */
+
+	DRM_WAIT_ON(ret, dev->vbl_queue, 3 * DRM_HZ,
+		    (((cur_vblank = atomic_read(&dev->vbl_received)) -
+		      *sequence) <= (1 << 23)));
+	
+	*sequence = cur_vblank;
+	return ret;
+}
+
+static int 
+via_driver_irq_wait(drm_device_t * dev, unsigned int irq, int force_sequence,
+		    unsigned int *sequence)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	unsigned int cur_irq_sequence;
+	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
+	int ret = 0;
+	maskarray_t *masks = dev_priv->irq_masks;
+
+	DRM_DEBUG("%s\n", __FUNCTION__);
+
+	if (!dev_priv) {
+		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
+		return DRM_ERR(EINVAL);
+	}
+
+	if (irq >= dev_priv->num_irqs ) {
+		DRM_ERROR("%s Trying to wait on unknown irq %d\n", __FUNCTION__, irq);
+		return DRM_ERR(EINVAL);
+	}
+		
+	cur_irq += irq;
+
+	if (masks[irq][2] && !force_sequence) {
+		DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
+			    ((VIA_READ(masks[irq][2]) & masks[irq][3]) == masks[irq][4]));
+		cur_irq_sequence = atomic_read(&cur_irq->irq_received);
+	} else {
+		DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
+			    (((cur_irq_sequence = atomic_read(&cur_irq->irq_received)) -
+			      *sequence) <= (1 << 23)));		
+	}
+	*sequence = cur_irq_sequence;
+	return ret;
+}
+
+
+/*
+ * drm_dma.h hooks
+ */
+
+void via_driver_irq_preinstall(drm_device_t * dev)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	u32 status;
+	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
+	int i;
+
+	DRM_DEBUG("driver_irq_preinstall: dev_priv: %p\n", dev_priv);
+	if (dev_priv) {
+
+		dev_priv->irq_enable_mask = VIA_IRQ_VBLANK_ENABLE;
+		dev_priv->irq_pending_mask = VIA_IRQ_VBLANK_PENDING;
+
+		dev_priv->irq_masks = (dev_priv->pro_group_a) ?
+			via_pro_group_a_irqs : via_unichrome_irqs;
+		dev_priv->num_irqs = (dev_priv->pro_group_a) ?
+			via_num_pro_group_a : via_num_unichrome;
+		
+		for(i=0; i < dev_priv->num_irqs; ++i) {
+			atomic_set(&cur_irq->irq_received, 0);
+			cur_irq->enable_mask = dev_priv->irq_masks[i][0]; 
+			cur_irq->pending_mask = dev_priv->irq_masks[i][1];
+			DRM_INIT_WAITQUEUE( &cur_irq->irq_queue );
+			dev_priv->irq_enable_mask |= cur_irq->enable_mask;
+			dev_priv->irq_pending_mask |= cur_irq->pending_mask;
+			cur_irq++;
+			
+			DRM_DEBUG("Initializing IRQ %d\n", i);
+		}
+			
+	        dev_priv->last_vblank_valid = 0;
+
+		// Clear VSync interrupt regs
+		status = VIA_READ(VIA_REG_INTERRUPT);
+		VIA_WRITE(VIA_REG_INTERRUPT, status & 
+			  ~(dev_priv->irq_enable_mask));
+		
+		/* Clear bits if they're already high */
+		viadrv_acknowledge_irqs(dev_priv);
+	}
+}
+
+void via_driver_irq_postinstall(drm_device_t * dev)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	u32 status;
+
+	DRM_DEBUG("via_driver_irq_postinstall\n");
+	if (dev_priv) {
+		status = VIA_READ(VIA_REG_INTERRUPT);
+		VIA_WRITE(VIA_REG_INTERRUPT, status | VIA_IRQ_GLOBAL
+			  | dev_priv->irq_enable_mask);
+
+		/* Some magic, oh for some data sheets ! */
+
+		VIA_WRITE8(0x83d4, 0x11);
+		VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) | 0x30);
+		
+	}
+}
+
+void via_driver_irq_uninstall(drm_device_t * dev)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	u32 status;
+
+	DRM_DEBUG("driver_irq_uninstall)\n");
+	if (dev_priv) {
+
+		/* Some more magic, oh for some data sheets ! */
+
+		VIA_WRITE8(0x83d4, 0x11);
+		VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);
+
+		status = VIA_READ(VIA_REG_INTERRUPT);
+		VIA_WRITE(VIA_REG_INTERRUPT, status & 
+			  ~(VIA_IRQ_VBLANK_ENABLE | dev_priv->irq_enable_mask));
+	}
+}
+
+int via_wait_irq(DRM_IOCTL_ARGS)
+{
+	drm_file_t *priv = filp->private_data;
+	drm_device_t *dev = priv->head->dev;
+	drm_via_irqwait_t __user *argp = (void __user *)data;
+	drm_via_irqwait_t irqwait;
+	struct timeval now;
+	int ret = 0;
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
+	int force_sequence;
+
+	if (!dev->irq)
+		return DRM_ERR(EINVAL);
+
+	DRM_COPY_FROM_USER_IOCTL(irqwait, argp, sizeof(irqwait));
+	if (irqwait.request.irq >= dev_priv->num_irqs) {
+		DRM_ERROR("%s Trying to wait on unknown irq %d\n", __FUNCTION__, 
+			  irqwait.request.irq);
+		return DRM_ERR(EINVAL);
+	}
+
+	cur_irq += irqwait.request.irq;
+
+	switch (irqwait.request.type & ~VIA_IRQ_FLAGS_MASK) {
+	case VIA_IRQ_RELATIVE:
+		irqwait.request.sequence += atomic_read(&cur_irq->irq_received);
+		irqwait.request.type &= ~_DRM_VBLANK_RELATIVE;
+	case VIA_IRQ_ABSOLUTE:
+		break;
+	default:
+		return DRM_ERR(EINVAL);
+	}
+
+	if (irqwait.request.type & VIA_IRQ_SIGNAL) {
+		DRM_ERROR("%s Signals on Via IRQs not implemented yet.\n", 
+			  __FUNCTION__);
+		return DRM_ERR(EINVAL);
+	}
+
+	force_sequence = (irqwait.request.type & VIA_IRQ_FORCE_SEQUENCE);
+
+	ret = via_driver_irq_wait(dev, irqwait.request.irq, force_sequence,
+				  &irqwait.request.sequence);
+	do_gettimeofday(&now);
+	irqwait.reply.tval_sec = now.tv_sec;
+	irqwait.reply.tval_usec = now.tv_usec;
+
+	DRM_COPY_TO_USER_IOCTL(argp, irqwait, sizeof(irqwait));
+
+	return ret;
+}