[PATCH 4/4] dmaengine: Add Freescale i.MX1/21/27 DMA driver

[Sascha Hauer]

This driver is currently implemented as a user to the old i.MX
DMA API. This allows us to convert each user of the old API to
the dmaengine API one by one. Once this is done the old DMA
driver can be merged into the i.MX dmaengine driver.

Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
 drivers/dma/Kconfig   |    8 +
 drivers/dma/Makefile  |    1 +
 drivers/dma/imx-dma.c |  426 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 435 insertions(+), 0 deletions(-)
 create mode 100644 drivers/dma/imx-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 3cf1d12..e0e1f40 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -203,6 +203,14 @@ config IMX_SDMA
 	  Support the i.MX SDMA engine. This engine is integrated into
 	  Freescale i.MX25/31/35/51 chips.
 
+config IMX_DMA
+	tristate "i.MX DMA support"
+	depends on ARCH_MX1 || ARCH_MX21 || MACH_MX27
+	select DMA_ENGINE
+	help
+	  Support the i.MX DMA engine. This engine is integrated into
+	  Freescale i.MX1/21/27 chips.
+
 config DMA_ENGINE
 	bool
 
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 14d7a1b..a65801c 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
 obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
+obj-$(CONFIG_IMX_DMA) += imx-dma.o
diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
new file mode 100644
index 0000000..6ef82ba
--- /dev/null
+++ b/drivers/dma/imx-dma.c
@@ -0,0 +1,426 @@
+/*
+ * 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@xxxxxxxxxxxxxx>
+ *
+ * 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_data_direction		direction;
+	enum dma_slave_buswidth		word_size;
+	dma_addr_t			bd_phys;
+	unsigned long			flags;
+	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;
+printk("%s\n", __func__);
+	imxdmac->status = DMA_SUCCESS;
+	imxdma_handle(imxdmac);
+}
+
+static void imxdma_err_handler(int channel, void *data, int error)
+{
+	struct imxdma_channel *imxdmac = data;
+printk("%s 0x%08x\n", __func__, error);
+dump_stack();
+	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 (imxdmac->channel < 0)
+			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@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("i.MX dma driver");
+MODULE_LICENSE("GPL");
-- 
1.7.2.3

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