1 files changed, 671 insertions, 0 deletions

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
new file mode 100644
index 000000000000..05aea3ce8506
--- /dev/null
+++ b/drivers/dma/edma.c
@@ -0,0 +1,671 @@
+/*
+ * TI EDMA DMA engine driver
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <mach/edma.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+/*
+ * This will go away when the private EDMA API is folded
+ * into this driver and the platform device(s) are
+ * instantiated in the arch code. We can only get away
+ * with this simplification because DA8XX may not be built
+ * in the same kernel image with other DaVinci parts. This
+ * avoids having to sprinkle dmaengine driver platform devices
+ * and data throughout all the existing board files.
+ */
+#ifdef CONFIG_ARCH_DAVINCI_DA8XX
+#define EDMA_CTLRS	2
+#define EDMA_CHANS	32
+#else
+#define EDMA_CTLRS	1
+#define EDMA_CHANS	64
+#endif /* CONFIG_ARCH_DAVINCI_DA8XX */
+
+/* Max of 16 segments per channel to conserve PaRAM slots */
+#define MAX_NR_SG		16
+#define EDMA_MAX_SLOTS		MAX_NR_SG
+#define EDMA_DESCRIPTORS	16
+
+struct edma_desc {
+	struct virt_dma_desc		vdesc;
+	struct list_head		node;
+	int				absync;
+	int				pset_nr;
+	struct edmacc_param		pset[0];
+};
+
+struct edma_cc;
+
+struct edma_chan {
+	struct virt_dma_chan		vchan;
+	struct list_head		node;
+	struct edma_desc		*edesc;
+	struct edma_cc			*ecc;
+	int				ch_num;
+	bool				alloced;
+	int				slot[EDMA_MAX_SLOTS];
+	dma_addr_t			addr;
+	int				addr_width;
+	int				maxburst;
+};
+
+struct edma_cc {
+	int				ctlr;
+	struct dma_device		dma_slave;
+	struct edma_chan		slave_chans[EDMA_CHANS];
+	int				num_slave_chans;
+	int				dummy_slot;
+};
+
+static inline struct edma_cc *to_edma_cc(struct dma_device *d)
+{
+	return container_of(d, struct edma_cc, dma_slave);
+}
+
+static inline struct edma_chan *to_edma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct edma_chan, vchan.chan);
+}
+
+static inline struct edma_desc
+*to_edma_desc(struct dma_async_tx_descriptor *tx)
+{
+	return container_of(tx, struct edma_desc, vdesc.tx);
+}
+
+static void edma_desc_free(struct virt_dma_desc *vdesc)
+{
+	kfree(container_of(vdesc, struct edma_desc, vdesc));
+}
+
+/* Dispatch a queued descriptor to the controller (caller holds lock) */
+static void edma_execute(struct edma_chan *echan)
+{
+	struct virt_dma_desc *vdesc = vchan_next_desc(&echan->vchan);
+	struct edma_desc *edesc;
+	int i;
+
+	if (!vdesc) {
+		echan->edesc = NULL;
+		return;
+	}
+
+	list_del(&vdesc->node);
+
+	echan->edesc = edesc = to_edma_desc(&vdesc->tx);
+
+	/* Write descriptor PaRAM set(s) */
+	for (i = 0; i < edesc->pset_nr; i++) {
+		edma_write_slot(echan->slot[i], &edesc->pset[i]);
+		dev_dbg(echan->vchan.chan.device->dev,
+			"\n pset[%d]:\n"
+			"  chnum\t%d\n"
+			"  slot\t%d\n"
+			"  opt\t%08x\n"
+			"  src\t%08x\n"
+			"  dst\t%08x\n"
+			"  abcnt\t%08x\n"
+			"  ccnt\t%08x\n"
+			"  bidx\t%08x\n"
+			"  cidx\t%08x\n"
+			"  lkrld\t%08x\n",
+			i, echan->ch_num, echan->slot[i],
+			edesc->pset[i].opt,
+			edesc->pset[i].src,
+			edesc->pset[i].dst,
+			edesc->pset[i].a_b_cnt,
+			edesc->pset[i].ccnt,
+			edesc->pset[i].src_dst_bidx,
+			edesc->pset[i].src_dst_cidx,
+			edesc->pset[i].link_bcntrld);
+		/* Link to the previous slot if not the last set */
+		if (i != (edesc->pset_nr - 1))
+			edma_link(echan->slot[i], echan->slot[i+1]);
+		/* Final pset links to the dummy pset */
+		else
+			edma_link(echan->slot[i], echan->ecc->dummy_slot);
+	}
+
+	edma_start(echan->ch_num);
+}
+
+static int edma_terminate_all(struct edma_chan *echan)
+{
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&echan->vchan.lock, flags);
+
+	/*
+	 * Stop DMA activity: we assume the callback will not be called
+	 * after edma_dma() returns (even if it does, it will see
+	 * echan->edesc is NULL and exit.)
+	 */
+	if (echan->edesc) {
+		echan->edesc = NULL;
+		edma_stop(echan->ch_num);
+	}
+
+	vchan_get_all_descriptors(&echan->vchan, &head);
+	spin_unlock_irqrestore(&echan->vchan.lock, flags);
+	vchan_dma_desc_free_list(&echan->vchan, &head);
+
+	return 0;
+}
+
+
+static int edma_slave_config(struct edma_chan *echan,
+	struct dma_slave_config *config)
+{
+	if ((config->src_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES) ||
+	    (config->dst_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
+		return -EINVAL;
+
+	if (config->direction == DMA_MEM_TO_DEV) {
+		if (config->dst_addr)
+			echan->addr = config->dst_addr;
+		if (config->dst_addr_width)
+			echan->addr_width = config->dst_addr_width;
+		if (config->dst_maxburst)
+			echan->maxburst = config->dst_maxburst;
+	} else if (config->direction == DMA_DEV_TO_MEM) {
+		if (config->src_addr)
+			echan->addr = config->src_addr;
+		if (config->src_addr_width)
+			echan->addr_width = config->src_addr_width;
+		if (config->src_maxburst)
+			echan->maxburst = config->src_maxburst;
+	}
+
+	return 0;
+}
+
+static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+			unsigned long arg)
+{
+	int ret = 0;
+	struct dma_slave_config *config;
+	struct edma_chan *echan = to_edma_chan(chan);
+
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		edma_terminate_all(echan);
+		break;
+	case DMA_SLAVE_CONFIG:
+		config = (struct dma_slave_config *)arg;
+		ret = edma_slave_config(echan, config);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	return ret;
+}
+
+static struct dma_async_tx_descriptor *edma_prep_slave_sg(
+	struct dma_chan *chan, struct scatterlist *sgl,
+	unsigned int sg_len, enum dma_transfer_direction direction,
+	unsigned long tx_flags, void *context)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	struct device *dev = chan->device->dev;
+	struct edma_desc *edesc;
+	struct scatterlist *sg;
+	int i;
+	int acnt, bcnt, ccnt, src, dst, cidx;
+	int src_bidx, dst_bidx, src_cidx, dst_cidx;
+
+	if (unlikely(!echan || !sgl || !sg_len))
+		return NULL;
+
+	if (echan->addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
+		dev_err(dev, "Undefined slave buswidth\n");
+		return NULL;
+	}
+
+	if (sg_len > MAX_NR_SG) {
+		dev_err(dev, "Exceeded max SG segments %d > %d\n",
+			sg_len, MAX_NR_SG);
+		return NULL;
+	}
+
+	edesc = kzalloc(sizeof(*edesc) + sg_len *
+		sizeof(edesc->pset[0]), GFP_ATOMIC);
+	if (!edesc) {
+		dev_dbg(dev, "Failed to allocate a descriptor\n");
+		return NULL;
+	}
+
+	edesc->pset_nr = sg_len;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		/* Allocate a PaRAM slot, if needed */
+		if (echan->slot[i] < 0) {
+			echan->slot[i] =
+				edma_alloc_slot(EDMA_CTLR(echan->ch_num),
+						EDMA_SLOT_ANY);
+			if (echan->slot[i] < 0) {
+				dev_err(dev, "Failed to allocate slot\n");
+				return NULL;
+			}
+		}
+
+		acnt = echan->addr_width;
+
+		/*
+		 * If the maxburst is equal to the fifo width, use
+		 * A-synced transfers. This allows for large contiguous
+		 * buffer transfers using only one PaRAM set.
+		 */
+		if (echan->maxburst == 1) {
+			edesc->absync = false;
+			ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
+			bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
+			if (bcnt)
+				ccnt++;
+			else
+				bcnt = SZ_64K - 1;
+			cidx = acnt;
+		/*
+		 * If maxburst is greater than the fifo address_width,
+		 * use AB-synced transfers where A count is the fifo
+		 * address_width and B count is the maxburst. In this
+		 * case, we are limited to transfers of C count frames
+		 * of (address_width * maxburst) where C count is limited
+		 * to SZ_64K-1. This places an upper bound on the length
+		 * of an SG segment that can be handled.
+		 */
+		} else {
+			edesc->absync = true;
+			bcnt = echan->maxburst;
+			ccnt = sg_dma_len(sg) / (acnt * bcnt);
+			if (ccnt > (SZ_64K - 1)) {
+				dev_err(dev, "Exceeded max SG segment size\n");
+				return NULL;
+			}
+			cidx = acnt * bcnt;
+		}
+
+		if (direction == DMA_MEM_TO_DEV) {
+			src = sg_dma_address(sg);
+			dst = echan->addr;
+			src_bidx = acnt;
+			src_cidx = cidx;
+			dst_bidx = 0;
+			dst_cidx = 0;
+		} else {
+			src = echan->addr;
+			dst = sg_dma_address(sg);
+			src_bidx = 0;
+			src_cidx = 0;
+			dst_bidx = acnt;
+			dst_cidx = cidx;
+		}
+
+		edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num));
+		/* Configure A or AB synchronized transfers */
+		if (edesc->absync)
+			edesc->pset[i].opt |= SYNCDIM;
+		/* If this is the last set, enable completion interrupt flag */
+		if (i == sg_len - 1)
+			edesc->pset[i].opt |= TCINTEN;
+
+		edesc->pset[i].src = src;
+		edesc->pset[i].dst = dst;
+
+		edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx;
+		edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx;
+
+		edesc->pset[i].a_b_cnt = bcnt << 16 | acnt;
+		edesc->pset[i].ccnt = ccnt;
+		edesc->pset[i].link_bcntrld = 0xffffffff;
+
+	}
+
+	return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
+}
+
+static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
+{
+	struct edma_chan *echan = data;
+	struct device *dev = echan->vchan.chan.device->dev;
+	struct edma_desc *edesc;
+	unsigned long flags;
+
+	/* Stop the channel */
+	edma_stop(echan->ch_num);
+
+	switch (ch_status) {
+	case DMA_COMPLETE:
+		dev_dbg(dev, "transfer complete on channel %d\n", ch_num);
+
+		spin_lock_irqsave(&echan->vchan.lock, flags);
+
+		edesc = echan->edesc;
+		if (edesc) {
+			edma_execute(echan);
+			vchan_cookie_complete(&edesc->vdesc);
+		}
+
+		spin_unlock_irqrestore(&echan->vchan.lock, flags);
+
+		break;
+	case DMA_CC_ERROR:
+		dev_dbg(dev, "transfer error on channel %d\n", ch_num);
+		break;
+	default:
+		break;
+	}
+}
+
+/* Alloc channel resources */
+static int edma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	struct device *dev = chan->device->dev;
+	int ret;
+	int a_ch_num;
+	LIST_HEAD(descs);
+
+	a_ch_num = edma_alloc_channel(echan->ch_num, edma_callback,
+					chan, EVENTQ_DEFAULT);
+
+	if (a_ch_num < 0) {
+		ret = -ENODEV;
+		goto err_no_chan;
+	}
+
+	if (a_ch_num != echan->ch_num) {
+		dev_err(dev, "failed to allocate requested channel %u:%u\n",
+			EDMA_CTLR(echan->ch_num),
+			EDMA_CHAN_SLOT(echan->ch_num));
+		ret = -ENODEV;
+		goto err_wrong_chan;
+	}
+
+	echan->alloced = true;
+	echan->slot[0] = echan->ch_num;
+
+	dev_info(dev, "allocated channel for %u:%u\n",
+		 EDMA_CTLR(echan->ch_num), EDMA_CHAN_SLOT(echan->ch_num));
+
+	return 0;
+
+err_wrong_chan:
+	edma_free_channel(a_ch_num);
+err_no_chan:
+	return ret;
+}
+
+/* Free channel resources */
+static void edma_free_chan_resources(struct dma_chan *chan)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	struct device *dev = chan->device->dev;
+	int i;
+
+	/* Terminate transfers */
+	edma_stop(echan->ch_num);
+
+	vchan_free_chan_resources(&echan->vchan);
+
+	/* Free EDMA PaRAM slots */
+	for (i = 1; i < EDMA_MAX_SLOTS; i++) {
+		if (echan->slot[i] >= 0) {
+			edma_free_slot(echan->slot[i]);
+			echan->slot[i] = -1;
+		}
+	}
+
+	/* Free EDMA channel */
+	if (echan->alloced) {
+		edma_free_channel(echan->ch_num);
+		echan->alloced = false;
+	}
+
+	dev_info(dev, "freeing channel for %u\n", echan->ch_num);
+}
+
+/* Send pending descriptor to hardware */
+static void edma_issue_pending(struct dma_chan *chan)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&echan->vchan.lock, flags);
+	if (vchan_issue_pending(&echan->vchan) && !echan->edesc)
+		edma_execute(echan);
+	spin_unlock_irqrestore(&echan->vchan.lock, flags);
+}
+
+static size_t edma_desc_size(struct edma_desc *edesc)
+{
+	int i;
+	size_t size;
+
+	if (edesc->absync)
+		for (size = i = 0; i < edesc->pset_nr; i++)
+			size += (edesc->pset[i].a_b_cnt & 0xffff) *
+				(edesc->pset[i].a_b_cnt >> 16) *
+				 edesc->pset[i].ccnt;
+	else
+		size = (edesc->pset[0].a_b_cnt & 0xffff) *
+			(edesc->pset[0].a_b_cnt >> 16) +
+			(edesc->pset[0].a_b_cnt & 0xffff) *
+			(SZ_64K - 1) * edesc->pset[0].ccnt;
+
+	return size;
+}
+
+/* Check request completion status */
+static enum dma_status edma_tx_status(struct dma_chan *chan,
+				      dma_cookie_t cookie,
+				      struct dma_tx_state *txstate)
+{
+	struct edma_chan *echan = to_edma_chan(chan);
+	struct virt_dma_desc *vdesc;
+	enum dma_status ret;
+	unsigned long flags;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (ret == DMA_SUCCESS || !txstate)
+		return ret;
+
+	spin_lock_irqsave(&echan->vchan.lock, flags);
+	vdesc = vchan_find_desc(&echan->vchan, cookie);
+	if (vdesc) {
+		txstate->residue = edma_desc_size(to_edma_desc(&vdesc->tx));
+	} else if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) {
+		struct edma_desc *edesc = echan->edesc;
+		txstate->residue = edma_desc_size(edesc);
+	} else {
+		txstate->residue = 0;
+	}
+	spin_unlock_irqrestore(&echan->vchan.lock, flags);
+
+	return ret;
+}
+
+static void __init edma_chan_init(struct edma_cc *ecc,
+				  struct dma_device *dma,
+				  struct edma_chan *echans)
+{
+	int i, j;
+
+	for (i = 0; i < EDMA_CHANS; i++) {
+		struct edma_chan *echan = &echans[i];
+		echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i);
+		echan->ecc = ecc;
+		echan->vchan.desc_free = edma_desc_free;
+
+		vchan_init(&echan->vchan, dma);
+
+		INIT_LIST_HEAD(&echan->node);
+		for (j = 0; j < EDMA_MAX_SLOTS; j++)
+			echan->slot[j] = -1;
+	}
+}
+
+static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,
+			  struct device *dev)
+{
+	dma->device_prep_slave_sg = edma_prep_slave_sg;
+	dma->device_alloc_chan_resources = edma_alloc_chan_resources;
+	dma->device_free_chan_resources = edma_free_chan_resources;
+	dma->device_issue_pending = edma_issue_pending;
+	dma->device_tx_status = edma_tx_status;
+	dma->device_control = edma_control;
+	dma->dev = dev;
+
+	INIT_LIST_HEAD(&dma->channels);
+}
+
+static int __devinit edma_probe(struct platform_device *pdev)
+{
+	struct edma_cc *ecc;
+	int ret;
+
+	ecc = devm_kzalloc(&pdev->dev, sizeof(*ecc), GFP_KERNEL);
+	if (!ecc) {
+		dev_err(&pdev->dev, "Can't allocate controller\n");
+		return -ENOMEM;
+	}
+
+	ecc->ctlr = pdev->id;
+	ecc->dummy_slot = edma_alloc_slot(ecc->ctlr, EDMA_SLOT_ANY);
+	if (ecc->dummy_slot < 0) {
+		dev_err(&pdev->dev, "Can't allocate PaRAM dummy slot\n");
+		return -EIO;
+	}
+
+	dma_cap_zero(ecc->dma_slave.cap_mask);
+	dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask);
+
+	edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev);
+
+	edma_chan_init(ecc, &ecc->dma_slave, ecc->slave_chans);
+
+	ret = dma_async_device_register(&ecc->dma_slave);
+	if (ret)
+		goto err_reg1;
+
+	platform_set_drvdata(pdev, ecc);
+
+	dev_info(&pdev->dev, "TI EDMA DMA engine driver\n");
+
+	return 0;
+
+err_reg1:
+	edma_free_slot(ecc->dummy_slot);
+	return ret;
+}
+
+static int __devexit edma_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct edma_cc *ecc = dev_get_drvdata(dev);
+
+	dma_async_device_unregister(&ecc->dma_slave);
+	edma_free_slot(ecc->dummy_slot);
+
+	return 0;
+}
+
+static struct platform_driver edma_driver = {
+	.probe		= edma_probe,
+	.remove		= __devexit_p(edma_remove),
+	.driver = {
+		.name = "edma-dma-engine",
+		.owner = THIS_MODULE,
+	},
+};
+
+bool edma_filter_fn(struct dma_chan *chan, void *param)
+{
+	if (chan->device->dev->driver == &edma_driver.driver) {
+		struct edma_chan *echan = to_edma_chan(chan);
+		unsigned ch_req = *(unsigned *)param;
+		return ch_req == echan->ch_num;
+	}
+	return false;
+}
+EXPORT_SYMBOL(edma_filter_fn);
+
+static struct platform_device *pdev0, *pdev1;
+
+static const struct platform_device_info edma_dev_info0 = {
+	.name = "edma-dma-engine",
+	.id = 0,
+	.dma_mask = DMA_BIT_MASK(32),
+};
+
+static const struct platform_device_info edma_dev_info1 = {
+	.name = "edma-dma-engine",
+	.id = 1,
+	.dma_mask = DMA_BIT_MASK(32),
+};
+
+static int edma_init(void)
+{
+	int ret = platform_driver_register(&edma_driver);
+
+	if (ret == 0) {
+		pdev0 = platform_device_register_full(&edma_dev_info0);
+		if (IS_ERR(pdev0)) {
+			platform_driver_unregister(&edma_driver);
+			ret = PTR_ERR(pdev0);
+			goto out;
+		}
+	}
+
+	if (EDMA_CTLRS == 2) {
+		pdev1 = platform_device_register_full(&edma_dev_info1);
+		if (IS_ERR(pdev1)) {
+			platform_driver_unregister(&edma_driver);
+			platform_device_unregister(pdev0);
+			ret = PTR_ERR(pdev1);
+		}
+	}
+
+out:
+	return ret;
+}
+subsys_initcall(edma_init);
+
+static void __exit edma_exit(void)
+{
+	platform_device_unregister(pdev0);
+	if (pdev1)
+		platform_device_unregister(pdev1);
+	platform_driver_unregister(&edma_driver);
+}
+module_exit(edma_exit);
+
+MODULE_AUTHOR("Matt Porter <mporter@ti.com>");
+MODULE_DESCRIPTION("TI EDMA DMA engine driver");
+MODULE_LICENSE("GPL v2");