1 files changed, 298 insertions, 0 deletions
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
new file mode 100644
index 000000000..e651c4d0a
--- /dev/null
+++ b/arch/arm/kernel/dma.c
@@ -0,0 +1,298 @@
+/*
+ *  linux/arch/arm/kernel/dma.c
+ *
+ *  Copyright (C) 1995-2000 Russell King
+ *
+ * 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.
+ *
+ *  Front-end to the DMA handling.  This handles the allocation/freeing
+ *  of DMA channels, and provides a unified interface to the machines
+ *  DMA facilities.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/scatterlist.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#include <asm/dma.h>
+
+#include <asm/mach/dma.h>
+
+DEFINE_RAW_SPINLOCK(dma_spin_lock);
+EXPORT_SYMBOL(dma_spin_lock);
+
+static dma_t *dma_chan[MAX_DMA_CHANNELS];
+
+static inline dma_t *dma_channel(unsigned int chan)
+{
+	if (chan >= MAX_DMA_CHANNELS)
+		return NULL;
+
+	return dma_chan[chan];
+}
+
+int __init isa_dma_add(unsigned int chan, dma_t *dma)
+{
+	if (!dma->d_ops)
+		return -EINVAL;
+
+	sg_init_table(&dma->buf, 1);
+
+	if (dma_chan[chan])
+		return -EBUSY;
+	dma_chan[chan] = dma;
+	return 0;
+}
+
+/*
+ * Request DMA channel
+ *
+ * On certain platforms, we have to allocate an interrupt as well...
+ */
+int request_dma(unsigned int chan, const char *device_id)
+{
+	dma_t *dma = dma_channel(chan);
+	int ret;
+
+	if (!dma)
+		goto bad_dma;
+
+	if (xchg(&dma->lock, 1) != 0)
+		goto busy;
+
+	dma->device_id = device_id;
+	dma->active    = 0;
+	dma->invalid   = 1;
+
+	ret = 0;
+	if (dma->d_ops->request)
+		ret = dma->d_ops->request(chan, dma);
+
+	if (ret)
+		xchg(&dma->lock, 0);
+
+	return ret;
+
+bad_dma:
+	pr_err("dma: trying to allocate DMA%d\n", chan);
+	return -EINVAL;
+
+busy:
+	return -EBUSY;
+}
+EXPORT_SYMBOL(request_dma);
+
+/*
+ * Free DMA channel
+ *
+ * On certain platforms, we have to free interrupt as well...
+ */
+void free_dma(unsigned int chan)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (!dma)
+		goto bad_dma;
+
+	if (dma->active) {
+		pr_err("dma%d: freeing active DMA\n", chan);
+		dma->d_ops->disable(chan, dma);
+		dma->active = 0;
+	}
+
+	if (xchg(&dma->lock, 0) != 0) {
+		if (dma->d_ops->free)
+			dma->d_ops->free(chan, dma);
+		return;
+	}
+
+	pr_err("dma%d: trying to free free DMA\n", chan);
+	return;
+
+bad_dma:
+	pr_err("dma: trying to free DMA%d\n", chan);
+}
+EXPORT_SYMBOL(free_dma);
+
+/* Set DMA Scatter-Gather list
+ */
+void set_dma_sg (unsigned int chan, struct scatterlist *sg, int nr_sg)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (dma->active)
+		pr_err("dma%d: altering DMA SG while DMA active\n", chan);
+
+	dma->sg = sg;
+	dma->sgcount = nr_sg;
+	dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_sg);
+
+/* Set DMA address
+ *
+ * Copy address to the structure, and set the invalid bit
+ */
+void __set_dma_addr (unsigned int chan, void *addr)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (dma->active)
+		pr_err("dma%d: altering DMA address while DMA active\n", chan);
+
+	dma->sg = NULL;
+	dma->addr = addr;
+	dma->invalid = 1;
+}
+EXPORT_SYMBOL(__set_dma_addr);
+
+/* Set DMA byte count
+ *
+ * Copy address to the structure, and set the invalid bit
+ */
+void set_dma_count (unsigned int chan, unsigned long count)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (dma->active)
+		pr_err("dma%d: altering DMA count while DMA active\n", chan);
+
+	dma->sg = NULL;
+	dma->count = count;
+	dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_count);
+
+/* Set DMA direction mode
+ */
+void set_dma_mode (unsigned int chan, unsigned int mode)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (dma->active)
+		pr_err("dma%d: altering DMA mode while DMA active\n", chan);
+
+	dma->dma_mode = mode;
+	dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_mode);
+
+/* Enable DMA channel
+ */
+void enable_dma (unsigned int chan)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (!dma->lock)
+		goto free_dma;
+
+	if (dma->active == 0) {
+		dma->active = 1;
+		dma->d_ops->enable(chan, dma);
+	}
+	return;
+
+free_dma:
+	pr_err("dma%d: trying to enable free DMA\n", chan);
+	BUG();
+}
+EXPORT_SYMBOL(enable_dma);
+
+/* Disable DMA channel
+ */
+void disable_dma (unsigned int chan)
+{
+	dma_t *dma = dma_channel(chan);
+
+	if (!dma->lock)
+		goto free_dma;
+
+	if (dma->active == 1) {
+		dma->active = 0;
+		dma->d_ops->disable(chan, dma);
+	}
+	return;
+
+free_dma:
+	pr_err("dma%d: trying to disable free DMA\n", chan);
+	BUG();
+}
+EXPORT_SYMBOL(disable_dma);
+
+/*
+ * Is the specified DMA channel active?
+ */
+int dma_channel_active(unsigned int chan)
+{
+	dma_t *dma = dma_channel(chan);
+	return dma->active;
+}
+EXPORT_SYMBOL(dma_channel_active);
+
+void set_dma_page(unsigned int chan, char pagenr)
+{
+	pr_err("dma%d: trying to set_dma_page\n", chan);
+}
+EXPORT_SYMBOL(set_dma_page);
+
+void set_dma_speed(unsigned int chan, int cycle_ns)
+{
+	dma_t *dma = dma_channel(chan);
+	int ret = 0;
+
+	if (dma->d_ops->setspeed)
+		ret = dma->d_ops->setspeed(chan, dma, cycle_ns);
+	dma->speed = ret;
+}
+EXPORT_SYMBOL(set_dma_speed);
+
+int get_dma_residue(unsigned int chan)
+{
+	dma_t *dma = dma_channel(chan);
+	int ret = 0;
+
+	if (dma->d_ops->residue)
+		ret = dma->d_ops->residue(chan, dma);
+
+	return ret;
+}
+EXPORT_SYMBOL(get_dma_residue);
+
+#ifdef CONFIG_PROC_FS
+static int proc_dma_show(struct seq_file *m, void *v)
+{
+	int i;
+
+	for (i = 0 ; i < MAX_DMA_CHANNELS ; i++) {
+		dma_t *dma = dma_channel(i);
+		if (dma && dma->lock)
+			seq_printf(m, "%2d: %s\n", i, dma->device_id);
+	}
+	return 0;
+}
+
+static int proc_dma_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, proc_dma_show, NULL);
+}
+
+static const struct file_operations proc_dma_operations = {
+	.open		= proc_dma_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init proc_dma_init(void)
+{
+	proc_create("dma", 0, NULL, &proc_dma_operations);
+	return 0;
+}
+
+__initcall(proc_dma_init);
+#endif