1 files changed, 433 insertions, 0 deletions

diff --git a/drivers/dma/dma-jz4740.c b/drivers/dma/dma-jz4740.c
new file mode 100644
index 000000000000..3d424341d8fe
--- /dev/null
+++ b/drivers/dma/dma-jz4740.c
@@ -0,0 +1,433 @@
+/*
+ *  Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 DMAC support
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General	 Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/mach-jz4740/dma.h>
+
+#include "virt-dma.h"
+
+#define JZ_DMA_NR_CHANS 6
+
+struct jz4740_dma_sg {
+	dma_addr_t addr;
+	unsigned int len;
+};
+
+struct jz4740_dma_desc {
+	struct virt_dma_desc vdesc;
+
+	enum dma_transfer_direction direction;
+	bool cyclic;
+
+	unsigned int num_sgs;
+	struct jz4740_dma_sg sg[];
+};
+
+struct jz4740_dmaengine_chan {
+	struct virt_dma_chan vchan;
+	struct jz4740_dma_chan *jz_chan;
+
+	dma_addr_t fifo_addr;
+
+	struct jz4740_dma_desc *desc;
+	unsigned int next_sg;
+};
+
+struct jz4740_dma_dev {
+	struct dma_device ddev;
+
+	struct jz4740_dmaengine_chan chan[JZ_DMA_NR_CHANS];
+};
+
+static struct jz4740_dmaengine_chan *to_jz4740_dma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct jz4740_dmaengine_chan, vchan.chan);
+}
+
+static struct jz4740_dma_desc *to_jz4740_dma_desc(struct virt_dma_desc *vdesc)
+{
+	return container_of(vdesc, struct jz4740_dma_desc, vdesc);
+}
+
+static struct jz4740_dma_desc *jz4740_dma_alloc_desc(unsigned int num_sgs)
+{
+	return kzalloc(sizeof(struct jz4740_dma_desc) +
+		sizeof(struct jz4740_dma_sg) * num_sgs, GFP_ATOMIC);
+}
+
+static enum jz4740_dma_width jz4740_dma_width(enum dma_slave_buswidth width)
+{
+	switch (width) {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		return JZ4740_DMA_WIDTH_8BIT;
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		return JZ4740_DMA_WIDTH_16BIT;
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		return JZ4740_DMA_WIDTH_32BIT;
+	default:
+		return JZ4740_DMA_WIDTH_32BIT;
+	}
+}
+
+static enum jz4740_dma_transfer_size jz4740_dma_maxburst(u32 maxburst)
+{
+	if (maxburst <= 1)
+		return JZ4740_DMA_TRANSFER_SIZE_1BYTE;
+	else if (maxburst <= 3)
+		return JZ4740_DMA_TRANSFER_SIZE_2BYTE;
+	else if (maxburst <= 15)
+		return JZ4740_DMA_TRANSFER_SIZE_4BYTE;
+	else if (maxburst <= 31)
+		return JZ4740_DMA_TRANSFER_SIZE_16BYTE;
+
+	return JZ4740_DMA_TRANSFER_SIZE_32BYTE;
+}
+
+static int jz4740_dma_slave_config(struct dma_chan *c,
+	const struct dma_slave_config *config)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	struct jz4740_dma_config jzcfg;
+
+	switch (config->direction) {
+	case DMA_MEM_TO_DEV:
+		jzcfg.flags = JZ4740_DMA_SRC_AUTOINC;
+		jzcfg.transfer_size = jz4740_dma_maxburst(config->dst_maxburst);
+		chan->fifo_addr = config->dst_addr;
+		break;
+	case DMA_DEV_TO_MEM:
+		jzcfg.flags = JZ4740_DMA_DST_AUTOINC;
+		jzcfg.transfer_size = jz4740_dma_maxburst(config->src_maxburst);
+		chan->fifo_addr = config->src_addr;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+
+	jzcfg.src_width = jz4740_dma_width(config->src_addr_width);
+	jzcfg.dst_width = jz4740_dma_width(config->dst_addr_width);
+	jzcfg.mode = JZ4740_DMA_MODE_SINGLE;
+	jzcfg.request_type = config->slave_id;
+
+	jz4740_dma_configure(chan->jz_chan, &jzcfg);
+
+	return 0;
+}
+
+static int jz4740_dma_terminate_all(struct dma_chan *c)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	jz4740_dma_disable(chan->jz_chan);
+	chan->desc = NULL;
+	vchan_get_all_descriptors(&chan->vchan, &head);
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+	vchan_dma_desc_free_list(&chan->vchan, &head);
+
+	return 0;
+}
+
+static int jz4740_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+	unsigned long arg)
+{
+	struct dma_slave_config *config = (struct dma_slave_config *)arg;
+
+	switch (cmd) {
+	case DMA_SLAVE_CONFIG:
+		return jz4740_dma_slave_config(chan, config);
+	case DMA_TERMINATE_ALL:
+		return jz4740_dma_terminate_all(chan);
+	default:
+		return -ENOSYS;
+	}
+}
+
+static int jz4740_dma_start_transfer(struct jz4740_dmaengine_chan *chan)
+{
+	dma_addr_t src_addr, dst_addr;
+	struct virt_dma_desc *vdesc;
+	struct jz4740_dma_sg *sg;
+
+	jz4740_dma_disable(chan->jz_chan);
+
+	if (!chan->desc) {
+		vdesc = vchan_next_desc(&chan->vchan);
+		if (!vdesc)
+			return 0;
+		chan->desc = to_jz4740_dma_desc(vdesc);
+		chan->next_sg = 0;
+	}
+
+	if (chan->next_sg == chan->desc->num_sgs)
+		chan->next_sg = 0;
+
+	sg = &chan->desc->sg[chan->next_sg];
+
+	if (chan->desc->direction == DMA_MEM_TO_DEV) {
+		src_addr = sg->addr;
+		dst_addr = chan->fifo_addr;
+	} else {
+		src_addr = chan->fifo_addr;
+		dst_addr = sg->addr;
+	}
+	jz4740_dma_set_src_addr(chan->jz_chan, src_addr);
+	jz4740_dma_set_dst_addr(chan->jz_chan, dst_addr);
+	jz4740_dma_set_transfer_count(chan->jz_chan, sg->len);
+
+	chan->next_sg++;
+
+	jz4740_dma_enable(chan->jz_chan);
+
+	return 0;
+}
+
+static void jz4740_dma_complete_cb(struct jz4740_dma_chan *jz_chan, int error,
+	void *devid)
+{
+	struct jz4740_dmaengine_chan *chan = devid;
+
+	spin_lock(&chan->vchan.lock);
+	if (chan->desc) {
+		if (chan->desc && chan->desc->cyclic) {
+			vchan_cyclic_callback(&chan->desc->vdesc);
+		} else {
+			if (chan->next_sg == chan->desc->num_sgs) {
+				chan->desc = NULL;
+				vchan_cookie_complete(&chan->desc->vdesc);
+			}
+		}
+	}
+	jz4740_dma_start_transfer(chan);
+	spin_unlock(&chan->vchan.lock);
+}
+
+static void jz4740_dma_issue_pending(struct dma_chan *c)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	if (vchan_issue_pending(&chan->vchan) && !chan->desc)
+		jz4740_dma_start_transfer(chan);
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static struct dma_async_tx_descriptor *jz4740_dma_prep_slave_sg(
+	struct dma_chan *c, struct scatterlist *sgl,
+	unsigned int sg_len, enum dma_transfer_direction direction,
+	unsigned long flags, void *context)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	struct jz4740_dma_desc *desc;
+	struct scatterlist *sg;
+	unsigned int i;
+
+	desc = jz4740_dma_alloc_desc(sg_len);
+	if (!desc)
+		return NULL;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		desc->sg[i].addr = sg_dma_address(sg);
+		desc->sg[i].len = sg_dma_len(sg);
+	}
+
+	desc->num_sgs = sg_len;
+	desc->direction = direction;
+	desc->cyclic = false;
+
+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *jz4740_dma_prep_dma_cyclic(
+	struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
+	size_t period_len, enum dma_transfer_direction direction,
+	unsigned long flags, void *context)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	struct jz4740_dma_desc *desc;
+	unsigned int num_periods, i;
+
+	if (buf_len % period_len)
+		return NULL;
+
+	num_periods = buf_len / period_len;
+
+	desc = jz4740_dma_alloc_desc(num_periods);
+	if (!desc)
+		return NULL;
+
+	for (i = 0; i < num_periods; i++) {
+		desc->sg[i].addr = buf_addr;
+		desc->sg[i].len = period_len;
+		buf_addr += period_len;
+	}
+
+	desc->num_sgs = num_periods;
+	desc->direction = direction;
+	desc->cyclic = true;
+
+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
+static size_t jz4740_dma_desc_residue(struct jz4740_dmaengine_chan *chan,
+	struct jz4740_dma_desc *desc, unsigned int next_sg)
+{
+	size_t residue = 0;
+	unsigned int i;
+
+	residue = 0;
+
+	for (i = next_sg; i < desc->num_sgs; i++)
+		residue += desc->sg[i].len;
+
+	if (next_sg != 0)
+		residue += jz4740_dma_get_residue(chan->jz_chan);
+
+	return residue;
+}
+
+static enum dma_status jz4740_dma_tx_status(struct dma_chan *c,
+	dma_cookie_t cookie, struct dma_tx_state *state)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+	struct virt_dma_desc *vdesc;
+	enum dma_status status;
+	unsigned long flags;
+
+	status = dma_cookie_status(c, cookie, state);
+	if (status == DMA_SUCCESS || !state)
+		return status;
+
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	vdesc = vchan_find_desc(&chan->vchan, cookie);
+	if (cookie == chan->desc->vdesc.tx.cookie) {
+		state->residue = jz4740_dma_desc_residue(chan, chan->desc,
+				chan->next_sg);
+	} else if (vdesc) {
+		state->residue = jz4740_dma_desc_residue(chan,
+				to_jz4740_dma_desc(vdesc), 0);
+	} else {
+		state->residue = 0;
+	}
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+	return status;
+}
+
+static int jz4740_dma_alloc_chan_resources(struct dma_chan *c)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+
+	chan->jz_chan = jz4740_dma_request(chan, NULL);
+	if (!chan->jz_chan)
+		return -EBUSY;
+
+	jz4740_dma_set_complete_cb(chan->jz_chan, jz4740_dma_complete_cb);
+
+	return 0;
+}
+
+static void jz4740_dma_free_chan_resources(struct dma_chan *c)
+{
+	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
+
+	vchan_free_chan_resources(&chan->vchan);
+	jz4740_dma_free(chan->jz_chan);
+	chan->jz_chan = NULL;
+}
+
+static void jz4740_dma_desc_free(struct virt_dma_desc *vdesc)
+{
+	kfree(container_of(vdesc, struct jz4740_dma_desc, vdesc));
+}
+
+static int jz4740_dma_probe(struct platform_device *pdev)
+{
+	struct jz4740_dmaengine_chan *chan;
+	struct jz4740_dma_dev *dmadev;
+	struct dma_device *dd;
+	unsigned int i;
+	int ret;
+
+	dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
+	if (!dmadev)
+		return -EINVAL;
+
+	dd = &dmadev->ddev;
+
+	dma_cap_set(DMA_SLAVE, dd->cap_mask);
+	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
+	dd->device_alloc_chan_resources = jz4740_dma_alloc_chan_resources;
+	dd->device_free_chan_resources = jz4740_dma_free_chan_resources;
+	dd->device_tx_status = jz4740_dma_tx_status;
+	dd->device_issue_pending = jz4740_dma_issue_pending;
+	dd->device_prep_slave_sg = jz4740_dma_prep_slave_sg;
+	dd->device_prep_dma_cyclic = jz4740_dma_prep_dma_cyclic;
+	dd->device_control = jz4740_dma_control;
+	dd->dev = &pdev->dev;
+	dd->chancnt = JZ_DMA_NR_CHANS;
+	INIT_LIST_HEAD(&dd->channels);
+
+	for (i = 0; i < dd->chancnt; i++) {
+		chan = &dmadev->chan[i];
+		chan->vchan.desc_free = jz4740_dma_desc_free;
+		vchan_init(&chan->vchan, dd);
+	}
+
+	ret = dma_async_device_register(dd);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, dmadev);
+
+	return 0;
+}
+
+static int jz4740_dma_remove(struct platform_device *pdev)
+{
+	struct jz4740_dma_dev *dmadev = platform_get_drvdata(pdev);
+
+	dma_async_device_unregister(&dmadev->ddev);
+
+	return 0;
+}
+
+static struct platform_driver jz4740_dma_driver = {
+	.probe = jz4740_dma_probe,
+	.remove = jz4740_dma_remove,
+	.driver = {
+		.name = "jz4740-dma",
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(jz4740_dma_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("JZ4740 DMA driver");
+MODULE_LICENSE("GPLv2");