Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

arch/arm/mach-imx/dma.c

@@ -0,0 +1,203 @@
+/*
+ *  linux/arch/arm/mach-imx/dma.c
+ *
+ *  imx DMA registration and IRQ dispatching
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  03/03/2004 Sascha Hauer <sascha@saschahauer.de>
+ *             initial version heavily inspired by
+ *             linux/arch/arm/mach-pxa/dma.c
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hardware.h>
+#include <asm/dma.h>
+
+static struct dma_channel {
+	char *name;
+	void (*irq_handler) (int, void *, struct pt_regs *);
+	void (*err_handler) (int, void *, struct pt_regs *);
+	void *data;
+} dma_channels[11];
+
+/* set err_handler to NULL to have the standard info-only error handler */
+int
+imx_request_dma(char *name, imx_dma_prio prio,
+		void (*irq_handler) (int, void *, struct pt_regs *),
+		void (*err_handler) (int, void *, struct pt_regs *), void *data)
+{
+	unsigned long flags;
+	int i, found = 0;
+
+	/* basic sanity checks */
+	if (!name || !irq_handler)
+		return -EINVAL;
+
+	local_irq_save(flags);
+
+	/* try grabbing a DMA channel with the requested priority */
+	for (i = prio; i < prio + (prio == DMA_PRIO_LOW) ? 8 : 4; i++) {
+		if (!dma_channels[i].name) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		/* requested prio group is full, try hier priorities */
+		for (i = prio - 1; i >= 0; i--) {
+			if (!dma_channels[i].name) {
+				found = 1;
+				break;
+			}
+		}
+	}
+
+	if (found) {
+		DIMR &= ~(1 << i);
+		dma_channels[i].name = name;
+		dma_channels[i].irq_handler = irq_handler;
+		dma_channels[i].err_handler = err_handler;
+		dma_channels[i].data = data;
+	} else {
+		printk(KERN_WARNING "No more available DMA channels for %s\n",
+		       name);
+		i = -ENODEV;
+	}
+
+	local_irq_restore(flags);
+	return i;
+}
+
+void
+imx_free_dma(int dma_ch)
+{
+	unsigned long flags;
+
+	if (!dma_channels[dma_ch].name) {
+		printk(KERN_CRIT
+		       "%s: trying to free channel %d which is already freed\n",
+		       __FUNCTION__, dma_ch);
+		return;
+	}
+
+	local_irq_save(flags);
+	DIMR &= ~(1 << dma_ch);
+	dma_channels[dma_ch].name = NULL;
+	local_irq_restore(flags);
+}
+
+static irqreturn_t
+dma_err_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int i, disr = DISR;
+	struct dma_channel *channel;
+	unsigned int err_mask = DBTOSR | DRTOSR | DSESR | DBOSR;
+
+	DISR = disr;
+	for (i = 0; i < 11; i++) {
+		channel = &dma_channels[i];
+
+		if ( (err_mask & 1<<i) && channel->name && channel->err_handler) {
+			channel->err_handler(i, channel->data, regs);
+			continue;
+		}
+
+		if (DBTOSR & (1 << i)) {
+			printk(KERN_WARNING
+			       "Burst timeout on channel %d (%s)\n",
+			       i, channel->name);
+			DBTOSR |= (1 << i);
+		}
+		if (DRTOSR & (1 << i)) {
+			printk(KERN_WARNING
+			       "Request timeout on channel %d (%s)\n",
+			       i, channel->name);
+			DRTOSR |= (1 << i);
+		}
+		if (DSESR & (1 << i)) {
+			printk(KERN_WARNING
+			       "Transfer timeout on channel %d (%s)\n",
+			       i, channel->name);
+			DSESR |= (1 << i);
+		}
+		if (DBOSR & (1 << i)) {
+			printk(KERN_WARNING
+			       "Buffer overflow timeout on channel %d (%s)\n",
+			       i, channel->name);
+			DBOSR |= (1 << i);
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int i, disr = DISR;
+
+	DISR = disr;
+	for (i = 0; i < 11; i++) {
+		if (disr & (1 << i)) {
+			struct dma_channel *channel = &dma_channels[i];
+			if (channel->name && channel->irq_handler) {
+				channel->irq_handler(i, channel->data, regs);
+			} else {
+				/*
+				 * IRQ for an unregistered DMA channel:
+				 * let's clear the interrupts and disable it.
+				 */
+				printk(KERN_WARNING
+				       "spurious IRQ for DMA channel %d\n", i);
+			}
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+static int __init
+imx_dma_init(void)
+{
+	int ret;
+
+	/* reset DMA module */
+	DCR = DCR_DRST;
+
+	ret = request_irq(DMA_INT, dma_irq_handler, 0, "DMA", NULL);
+	if (ret) {
+		printk(KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
+		return ret;
+	}
+
+	ret = request_irq(DMA_ERR, dma_err_handler, 0, "DMA", NULL);
+	if (ret) {
+		printk(KERN_CRIT "Wow!  Can't register ERRIRQ for DMA\n");
+		free_irq(DMA_INT, NULL);
+	}
+
+	/* enable DMA module */
+	DCR = DCR_DEN;
+
+	/* clear all interrupts */
+	DISR = 0x3ff;
+
+	/* enable interrupts */
+	DIMR = 0;
+
+	return ret;
+}
+
+arch_initcall(imx_dma_init);
+
+EXPORT_SYMBOL(imx_request_dma);
+EXPORT_SYMBOL(imx_free_dma);