1 files changed, 424 insertions, 0 deletions

diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
new file mode 100644
index 0000000..f629e49
--- /dev/null
+++ b/drivers/dma/imx-dma.c
@@ -0,0 +1,424 @@
+/*
+ * drivers/dma/imx-dma.c
+ *
+ * This file contains a driver for the Freescale i.MX DMA engine
+ * found on i.MX1/21/27
+ *
+ * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+
+#include <asm/irq.h>
+#include <mach/dma-v1.h>
+#include <mach/hardware.h>
+
+struct imxdma_channel {
+	struct imxdma_engine		*imxdma;
+	unsigned int			channel;
+	unsigned int			imxdma_channel;
+
+	enum dma_slave_buswidth		word_size;
+	dma_addr_t			per_address;
+	u32				watermark_level;
+	struct dma_chan			chan;
+	spinlock_t			lock;
+	struct dma_async_tx_descriptor	desc;
+	dma_cookie_t			last_completed;
+	enum dma_status			status;
+	int				dma_request;
+	struct scatterlist		*sg_list;
+};
+
+#define MAX_DMA_CHANNELS 8
+
+struct imxdma_engine {
+	struct device			*dev;
+	struct dma_device		dma_device;
+	struct imxdma_channel		channel[MAX_DMA_CHANNELS];
+};
+
+static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct imxdma_channel, chan);
+}
+
+static void imxdma_handle(struct imxdma_channel *imxdmac)
+{
+	if (imxdmac->desc.callback)
+		imxdmac->desc.callback(imxdmac->desc.callback_param);
+	imxdmac->last_completed = imxdmac->desc.cookie;
+}
+
+static void imxdma_irq_handler(int channel, void *data)
+{
+	struct imxdma_channel *imxdmac = data;
+
+	imxdmac->status = DMA_SUCCESS;
+	imxdma_handle(imxdmac);
+}
+
+static void imxdma_err_handler(int channel, void *data, int error)
+{
+	struct imxdma_channel *imxdmac = data;
+
+	imxdmac->status = DMA_ERROR;
+	imxdma_handle(imxdmac);
+}
+
+static void imxdma_progression(int channel, void *data,
+		struct scatterlist *sg)
+{
+	struct imxdma_channel *imxdmac = data;
+
+	imxdmac->status = DMA_SUCCESS;
+	imxdma_handle(imxdmac);
+}
+
+static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+		unsigned long arg)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+	struct dma_slave_config *dmaengine_cfg = (void *)arg;
+	int ret;
+	unsigned int mode = 0;
+
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		imxdmac->status = DMA_ERROR;
+		imx_dma_disable(imxdmac->imxdma_channel);
+		return 0;
+	case DMA_SLAVE_CONFIG:
+		if (dmaengine_cfg->direction == DMA_FROM_DEVICE) {
+			imxdmac->per_address = dmaengine_cfg->src_addr;
+			imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
+			imxdmac->word_size = dmaengine_cfg->src_addr_width;
+		} else {
+			imxdmac->per_address = dmaengine_cfg->dst_addr;
+			imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
+			imxdmac->word_size = dmaengine_cfg->dst_addr_width;
+		}
+
+		switch (imxdmac->word_size) {
+		case DMA_SLAVE_BUSWIDTH_1_BYTE:
+			mode = IMX_DMA_MEMSIZE_8;
+			break;
+		case DMA_SLAVE_BUSWIDTH_2_BYTES:
+			mode = IMX_DMA_MEMSIZE_16;
+			break;
+		default:
+		case DMA_SLAVE_BUSWIDTH_4_BYTES:
+			mode = IMX_DMA_MEMSIZE_32;
+			break;
+		}
+		ret = imx_dma_config_channel(imxdmac->imxdma_channel,
+				mode | IMX_DMA_TYPE_FIFO,
+				IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
+				imxdmac->dma_request, 1);
+
+		if (ret)
+			return ret;
+
+		imx_dma_config_burstlen(imxdmac->imxdma_channel, imxdmac->watermark_level);
+
+		return 0;
+	default:
+		return -ENOSYS;
+	}
+
+	return -EINVAL;
+}
+
+static enum dma_status imxdma_tx_status(struct dma_chan *chan,
+					    dma_cookie_t cookie,
+					    struct dma_tx_state *txstate)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+	dma_cookie_t last_used;
+	enum dma_status ret;
+
+	last_used = chan->cookie;
+
+	ret = dma_async_is_complete(cookie, imxdmac->last_completed, last_used);
+	dma_set_tx_state(txstate, imxdmac->last_completed, last_used, 0);
+
+	return ret;
+}
+
+static dma_cookie_t imxdma_assign_cookie(struct imxdma_channel *imxdma)
+{
+	dma_cookie_t cookie = imxdma->chan.cookie;
+
+	if (++cookie < 0)
+		cookie = 1;
+
+	imxdma->chan.cookie = cookie;
+	imxdma->desc.cookie = cookie;
+
+	return cookie;
+}
+
+static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
+	dma_cookie_t cookie;
+
+	spin_lock_irq(&imxdmac->lock);
+
+	cookie = imxdma_assign_cookie(imxdmac);
+
+	imx_dma_enable(imxdmac->imxdma_channel);
+
+	spin_unlock_irq(&imxdmac->lock);
+
+	return cookie;
+}
+
+static int imxdma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+	struct imx_dma_data *data = chan->private;
+
+	imxdmac->dma_request = data->dma_request;
+
+	dma_async_tx_descriptor_init(&imxdmac->desc, chan);
+	imxdmac->desc.tx_submit = imxdma_tx_submit;
+	/* txd.flags will be overwritten in prep funcs */
+	imxdmac->desc.flags = DMA_CTRL_ACK;
+
+	imxdmac->status = DMA_SUCCESS;
+
+	return 0;
+}
+
+static void imxdma_free_chan_resources(struct dma_chan *chan)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+
+	imx_dma_disable(imxdmac->imxdma_channel);
+
+	if (imxdmac->sg_list) {
+		kfree(imxdmac->sg_list);
+		imxdmac->sg_list = NULL;
+	}
+}
+
+static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_data_direction direction,
+		unsigned long flags)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+	struct scatterlist *sg;
+	int i, ret, dma_length = 0;
+	unsigned int dmamode;
+
+	if (imxdmac->status == DMA_IN_PROGRESS)
+		return NULL;
+
+	imxdmac->status = DMA_IN_PROGRESS;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		dma_length += sg->length;
+	}
+
+	if (direction == DMA_FROM_DEVICE)
+		dmamode = DMA_MODE_READ;
+	else
+		dmamode = DMA_MODE_WRITE;
+
+	ret = imx_dma_setup_sg(imxdmac->imxdma_channel, sgl, sg_len,
+		 dma_length, imxdmac->per_address, dmamode);
+	if (ret)
+		return NULL;
+
+	return &imxdmac->desc;
+}
+
+static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
+		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+		size_t period_len, enum dma_data_direction direction)
+{
+	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
+	struct imxdma_engine *imxdma = imxdmac->imxdma;
+	int i, ret;
+	unsigned int periods = buf_len / period_len;
+	unsigned int dmamode;
+
+	dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
+			__func__, imxdmac->channel, buf_len, period_len);
+
+	if (imxdmac->status == DMA_IN_PROGRESS)
+		return NULL;
+	imxdmac->status = DMA_IN_PROGRESS;
+
+	ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
+			imxdma_progression);
+	if (ret) {
+		dev_err(imxdma->dev, "Failed to setup the DMA handler\n");
+		return NULL;
+	}
+
+	if (imxdmac->sg_list)
+		kfree(imxdmac->sg_list);
+
+	imxdmac->sg_list = kcalloc(periods + 1,
+			sizeof(struct scatterlist), GFP_KERNEL);
+	if (!imxdmac->sg_list)
+		return NULL;
+
+	sg_init_table(imxdmac->sg_list, periods);
+
+	for (i = 0; i < periods; i++) {
+		imxdmac->sg_list[i].page_link = 0;
+		imxdmac->sg_list[i].offset = 0;
+		imxdmac->sg_list[i].dma_address = dma_addr;
+		imxdmac->sg_list[i].length = period_len;
+		dma_addr += period_len;
+	}
+
+	/* close the loop */
+	imxdmac->sg_list[periods].offset = 0;
+	imxdmac->sg_list[periods].length = 0;
+	imxdmac->sg_list[periods].page_link =
+		((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;
+
+	if (direction == DMA_FROM_DEVICE)
+		dmamode = DMA_MODE_READ;
+	else
+		dmamode = DMA_MODE_WRITE;
+
+	ret = imx_dma_setup_sg(imxdmac->imxdma_channel, imxdmac->sg_list, periods,
+		 IMX_DMA_LENGTH_LOOP, imxdmac->per_address, dmamode);
+	if (ret)
+		return NULL;
+
+	return &imxdmac->desc;
+}
+
+static void imxdma_issue_pending(struct dma_chan *chan)
+{
+	/*
+	 * Nothing to do. We only have a single descriptor
+	 */
+}
+
+static int __init imxdma_probe(struct platform_device *pdev)
+{
+	struct imxdma_engine *imxdma;
+	int ret, i;
+
+	imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
+	if (!imxdma)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&imxdma->dma_device.channels);
+
+	/* Initialize channel parameters */
+	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+		struct imxdma_channel *imxdmac = &imxdma->channel[i];
+
+		imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine",
+				DMA_PRIO_MEDIUM);
+		if ((int)imxdmac->channel < 0) {
+			ret = -ENODEV;
+			goto err_init;
+		}
+
+		imx_dma_setup_handlers(imxdmac->imxdma_channel,
+		       imxdma_irq_handler, imxdma_err_handler, imxdmac);
+
+		imxdmac->imxdma = imxdma;
+		spin_lock_init(&imxdmac->lock);
+
+		dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
+		dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
+
+		imxdmac->chan.device = &imxdma->dma_device;
+		imxdmac->chan.chan_id = i;
+		imxdmac->channel = i;
+
+		/* Add the channel to the DMAC list */
+		list_add_tail(&imxdmac->chan.device_node, &imxdma->dma_device.channels);
+	}
+
+	imxdma->dev = &pdev->dev;
+	imxdma->dma_device.dev = &pdev->dev;
+
+	imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
+	imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
+	imxdma->dma_device.device_tx_status = imxdma_tx_status;
+	imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
+	imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
+	imxdma->dma_device.device_control = imxdma_control;
+	imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
+
+	platform_set_drvdata(pdev, imxdma);
+
+	ret = dma_async_device_register(&imxdma->dma_device);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to register\n");
+		goto err_init;
+	}
+
+	return 0;
+
+err_init:
+	while (i-- >= 0) {
+		struct imxdma_channel *imxdmac = &imxdma->channel[i];
+		imx_dma_free(imxdmac->imxdma_channel);
+	}
+
+	kfree(imxdma);
+	return ret;
+}
+
+static int __exit imxdma_remove(struct platform_device *pdev)
+{
+	struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
+	int i;
+
+        dma_async_device_unregister(&imxdma->dma_device);
+
+	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+		struct imxdma_channel *imxdmac = &imxdma->channel[i];
+
+		 imx_dma_free(imxdmac->imxdma_channel);
+	}
+
+        kfree(imxdma);
+
+        return 0;
+}
+
+static struct platform_driver imxdma_driver = {
+	.driver		= {
+		.name	= "imx-dma",
+	},
+	.remove		= __exit_p(imxdma_remove),
+};
+
+static int __init imxdma_module_init(void)
+{
+	return platform_driver_probe(&imxdma_driver, imxdma_probe);
+}
+subsys_initcall(imxdma_module_init);
+
+MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("i.MX dma driver");
+MODULE_LICENSE("GPL");