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-rw-r--r--arch/sh/drivers/dma/dma-g2.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/arch/sh/drivers/dma/dma-g2.c b/arch/sh/drivers/dma/dma-g2.c
new file mode 100644
index 000000000..52a8ae5e3
--- /dev/null
+++ b/arch/sh/drivers/dma/dma-g2.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/sh/drivers/dma/dma-g2.c
+ *
+ * G2 bus DMA support
+ *
+ * Copyright (C) 2003 - 2006 Paul Mundt
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <asm/cacheflush.h>
+#include <mach/sysasic.h>
+#include <mach/dma.h>
+#include <asm/dma.h>
+
+struct g2_channel {
+ unsigned long g2_addr; /* G2 bus address */
+ unsigned long root_addr; /* Root bus (SH-4) address */
+ unsigned long size; /* Size (in bytes), 32-byte aligned */
+ unsigned long direction; /* Transfer direction */
+ unsigned long ctrl; /* Transfer control */
+ unsigned long chan_enable; /* Channel enable */
+ unsigned long xfer_enable; /* Transfer enable */
+ unsigned long xfer_stat; /* Transfer status */
+} __attribute__ ((aligned(32)));
+
+struct g2_status {
+ unsigned long g2_addr;
+ unsigned long root_addr;
+ unsigned long size;
+ unsigned long status;
+} __attribute__ ((aligned(16)));
+
+struct g2_dma_info {
+ struct g2_channel channel[G2_NR_DMA_CHANNELS];
+ unsigned long pad1[G2_NR_DMA_CHANNELS];
+ unsigned long wait_state;
+ unsigned long pad2[10];
+ unsigned long magic;
+ struct g2_status status[G2_NR_DMA_CHANNELS];
+} __attribute__ ((aligned(256)));
+
+static volatile struct g2_dma_info *g2_dma = (volatile struct g2_dma_info *)0xa05f7800;
+
+#define g2_bytes_remaining(i) \
+ ((g2_dma->channel[i].size - \
+ g2_dma->status[i].size) & 0x0fffffff)
+
+static irqreturn_t g2_dma_interrupt(int irq, void *dev_id)
+{
+ int i;
+
+ for (i = 0; i < G2_NR_DMA_CHANNELS; i++) {
+ if (g2_dma->status[i].status & 0x20000000) {
+ unsigned int bytes = g2_bytes_remaining(i);
+
+ if (likely(bytes == 0)) {
+ struct dma_info *info = dev_id;
+ struct dma_channel *chan = info->channels + i;
+
+ wake_up(&chan->wait_queue);
+
+ return IRQ_HANDLED;
+ }
+ }
+ }
+
+ return IRQ_NONE;
+}
+
+static int g2_enable_dma(struct dma_channel *chan)
+{
+ unsigned int chan_nr = chan->chan;
+
+ g2_dma->channel[chan_nr].chan_enable = 1;
+ g2_dma->channel[chan_nr].xfer_enable = 1;
+
+ return 0;
+}
+
+static int g2_disable_dma(struct dma_channel *chan)
+{
+ unsigned int chan_nr = chan->chan;
+
+ g2_dma->channel[chan_nr].chan_enable = 0;
+ g2_dma->channel[chan_nr].xfer_enable = 0;
+
+ return 0;
+}
+
+static int g2_xfer_dma(struct dma_channel *chan)
+{
+ unsigned int chan_nr = chan->chan;
+
+ if (chan->sar & 31) {
+ printk("g2dma: unaligned source 0x%lx\n", chan->sar);
+ return -EINVAL;
+ }
+
+ if (chan->dar & 31) {
+ printk("g2dma: unaligned dest 0x%lx\n", chan->dar);
+ return -EINVAL;
+ }
+
+ /* Align the count */
+ if (chan->count & 31)
+ chan->count = (chan->count + (32 - 1)) & ~(32 - 1);
+
+ /* Fixup destination */
+ chan->dar += 0xa0800000;
+
+ /* Fixup direction */
+ chan->mode = !chan->mode;
+
+ flush_icache_range((unsigned long)chan->sar, chan->count);
+
+ g2_disable_dma(chan);
+
+ g2_dma->channel[chan_nr].g2_addr = chan->dar & 0x1fffffe0;
+ g2_dma->channel[chan_nr].root_addr = chan->sar & 0x1fffffe0;
+ g2_dma->channel[chan_nr].size = (chan->count & ~31) | 0x80000000;
+ g2_dma->channel[chan_nr].direction = chan->mode;
+
+ /*
+ * bit 0 - ???
+ * bit 1 - if set, generate a hardware event on transfer completion
+ * bit 2 - ??? something to do with suspend?
+ */
+ g2_dma->channel[chan_nr].ctrl = 5; /* ?? */
+
+ g2_enable_dma(chan);
+
+ /* debug cruft */
+ pr_debug("count, sar, dar, mode, ctrl, chan, xfer: %ld, 0x%08lx, "
+ "0x%08lx, %ld, %ld, %ld, %ld\n",
+ g2_dma->channel[chan_nr].size,
+ g2_dma->channel[chan_nr].root_addr,
+ g2_dma->channel[chan_nr].g2_addr,
+ g2_dma->channel[chan_nr].direction,
+ g2_dma->channel[chan_nr].ctrl,
+ g2_dma->channel[chan_nr].chan_enable,
+ g2_dma->channel[chan_nr].xfer_enable);
+
+ return 0;
+}
+
+static int g2_get_residue(struct dma_channel *chan)
+{
+ return g2_bytes_remaining(chan->chan);
+}
+
+static struct dma_ops g2_dma_ops = {
+ .xfer = g2_xfer_dma,
+ .get_residue = g2_get_residue,
+};
+
+static struct dma_info g2_dma_info = {
+ .name = "g2_dmac",
+ .nr_channels = 4,
+ .ops = &g2_dma_ops,
+ .flags = DMAC_CHANNELS_TEI_CAPABLE,
+};
+
+static int __init g2_dma_init(void)
+{
+ int ret;
+
+ ret = request_irq(HW_EVENT_G2_DMA, g2_dma_interrupt, 0,
+ "g2 DMA handler", &g2_dma_info);
+ if (unlikely(ret))
+ return -EINVAL;
+
+ /* Magic */
+ g2_dma->wait_state = 27;
+ g2_dma->magic = 0x4659404f;
+
+ ret = register_dmac(&g2_dma_info);
+ if (unlikely(ret != 0))
+ free_irq(HW_EVENT_G2_DMA, &g2_dma_info);
+
+ return ret;
+}
+
+static void __exit g2_dma_exit(void)
+{
+ free_irq(HW_EVENT_G2_DMA, &g2_dma_info);
+ unregister_dmac(&g2_dma_info);
+}
+
+subsys_initcall(g2_dma_init);
+module_exit(g2_dma_exit);
+
+MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
+MODULE_DESCRIPTION("G2 bus DMA driver");
+MODULE_LICENSE("GPL v2");