summaryrefslogtreecommitdiffstats
path: root/arch/unicore32/kernel/dma.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-17 10:11:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-17 10:11:25 -0700
commit7b7adc4a016a1decb806eb71ecab98721fa7f146 (patch)
tree0a6f9a6e5659faa94604fbc575382a18f143c657 /arch/unicore32/kernel/dma.c
parent31598e8713ef501c8f6aad2e2ec8a9457e8877c1 (diff)
parent289d6b0e287e0acd85f3e6b7ea6c2cb5c234909a (diff)
downloadlinux-7b7adc4a016a1decb806eb71ecab98721fa7f146.tar.bz2
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/epip/linux-2.6-unicore32
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/epip/linux-2.6-unicore32: (40 commits) unicore32: rewrite arch-specific tlb.h to use asm-generic version unicore32: modify io_p2v and io_v2p macros, and adjust PKUNITY_mmio_BASEs unicore32: replace unicore32-specific iomap functions with generic lib implementation unicore32 machine related: add frame buffer driver for pkunity-v3 soc unicore32 machine related files: add i2c bus drivers for pkunity-v3 soc unicore32 io: redefine __REG(x) and re-use readl/writel funcs unicore32 i8042 upgrade and bugfix: adjust resource request region type unicore32 upgrade to v2.6.38-rc5: add one more paramter for pte_alloc_map call unicore32 i8042: adjust io funcs of i8042-unicore32io.h unicore32: rename PKUNITY_IOSPACE_BASE to PKUNITY_MMIO_BASE unicore32: modify function names and parameters for irq_chips unicore32: remove unused lines in arch/unicore32/include/asm/irq.h unicore32 time.c: change calculate method for clock_event_device unicore32: ADD MAINTAINER for unicore32 architecture unicore32 machine related files: ps2 driver unicore32 machine related files: pci bus handling unicore32 machine related files: hardware registers unicore32 machine related files: core files unicore32 additional architecture files: boot process unicore32 additional architecture files: low-level lib: misc ... Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32/kernel/dma.c')
-rw-r--r--arch/unicore32/kernel/dma.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/dma.c b/arch/unicore32/kernel/dma.c
new file mode 100644
index 000000000000..ae441bc3122c
--- /dev/null
+++ b/arch/unicore32/kernel/dma.c
@@ -0,0 +1,183 @@
+/*
+ * linux/arch/unicore32/kernel/dma.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ * Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <mach/hardware.h>
+#include <mach/dma.h>
+
+struct dma_channel {
+ char *name;
+ puv3_dma_prio prio;
+ void (*irq_handler)(int, void *);
+ void (*err_handler)(int, void *);
+ void *data;
+};
+
+static struct dma_channel dma_channels[MAX_DMA_CHANNELS];
+
+int puv3_request_dma(char *name, puv3_dma_prio prio,
+ void (*irq_handler)(int, void *),
+ void (*err_handler)(int, void *),
+ void *data)
+{
+ unsigned long flags;
+ int i, found = 0;
+
+ /* basic sanity checks */
+ if (!name)
+ return -EINVAL;
+
+ local_irq_save(flags);
+
+ do {
+ /* try grabbing a DMA channel with the requested priority */
+ for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ if ((dma_channels[i].prio == prio) &&
+ !dma_channels[i].name) {
+ found = 1;
+ break;
+ }
+ }
+ /* if requested prio group is full, try a hier priority */
+ } while (!found && prio--);
+
+ if (found) {
+ 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;
+}
+EXPORT_SYMBOL(puv3_request_dma);
+
+void puv3_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",
+ __func__, dma_ch);
+ return;
+ }
+
+ local_irq_save(flags);
+ dma_channels[dma_ch].name = NULL;
+ dma_channels[dma_ch].err_handler = NULL;
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(puv3_free_dma);
+
+static irqreturn_t dma_irq_handler(int irq, void *dev_id)
+{
+ int i, dint;
+
+ dint = readl(DMAC_ITCSR);
+ for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ if (dint & DMAC_CHANNEL(i)) {
+ struct dma_channel *channel = &dma_channels[i];
+
+ /* Clear TC interrupt of channel i */
+ writel(DMAC_CHANNEL(i), DMAC_ITCCR);
+ writel(0, DMAC_ITCCR);
+
+ if (channel->name && channel->irq_handler) {
+ channel->irq_handler(i, channel->data);
+ } 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 irqreturn_t dma_err_handler(int irq, void *dev_id)
+{
+ int i, dint;
+
+ dint = readl(DMAC_IESR);
+ for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ if (dint & DMAC_CHANNEL(i)) {
+ struct dma_channel *channel = &dma_channels[i];
+
+ /* Clear Err interrupt of channel i */
+ writel(DMAC_CHANNEL(i), DMAC_IECR);
+ writel(0, DMAC_IECR);
+
+ if (channel->name && channel->err_handler) {
+ channel->err_handler(i, channel->data);
+ } 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;
+}
+
+int __init puv3_init_dma(void)
+{
+ int i, ret;
+
+ /* dma channel priorities on v8 processors:
+ * ch 0 - 1 <--> (0) DMA_PRIO_HIGH
+ * ch 2 - 3 <--> (1) DMA_PRIO_MEDIUM
+ * ch 4 - 5 <--> (2) DMA_PRIO_LOW
+ */
+ for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+ puv3_stop_dma(i);
+ dma_channels[i].name = NULL;
+ dma_channels[i].prio = min((i & 0x7) >> 1, DMA_PRIO_LOW);
+ }
+
+ ret = request_irq(IRQ_DMA, dma_irq_handler, 0, "DMA", NULL);
+ if (ret) {
+ printk(KERN_CRIT "Can't register IRQ for DMA\n");
+ return ret;
+ }
+
+ ret = request_irq(IRQ_DMAERR, dma_err_handler, 0, "DMAERR", NULL);
+ if (ret) {
+ printk(KERN_CRIT "Can't register IRQ for DMAERR\n");
+ free_irq(IRQ_DMA, "DMA");
+ return ret;
+ }
+
+ return 0;
+}
+
+postcore_initcall(puv3_init_dma);