--- /dev/null
+/*
+ * 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 (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@pengutronix.de>");
+MODULE_DESCRIPTION("i.MX dma driver");
+MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff