[PATCH 3/7] dmaengine: st_fdma: Add STMicroelectronics FDMA engine driver support

[Peter Griffin]

This patch adds support for the Flexible Direct Memory Access (FDMA) core
driver. The FDMA is a slim core CPU with a dedicated firmware.
It is a general purpose DMA controller capable of supporting 16
independent DMA channels. Data moves maybe from memory to memory
or between memory and paced latency critical real time targets and it
is found on al STi based chipsets.

Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
 drivers/dma/Kconfig                       |   15 +
 drivers/dma/Makefile                      |    1 +
 drivers/dma/st_fdma.c                     | 1182 +++++++++++++++++++++++++++++
 drivers/dma/st_fdma.h                     |  234 ++++++
 include/linux/platform_data/dma-st_fdma.h |   70 ++
 5 files changed, 1502 insertions(+)
 create mode 100644 drivers/dma/st_fdma.c
 create mode 100644 drivers/dma/st_fdma.h
 create mode 100644 include/linux/platform_data/dma-st_fdma.h

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 88d474b..7a016e0 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -507,4 +507,19 @@ config QCOM_BAM_DMA
 	  Enable support for the QCOM BAM DMA controller.  This controller
 	  provides DMA capabilities for a variety of on-chip devices.
 
+config ST_FDMA
+	bool "ST FDMA dmaengine support"
+	depends on ARCH_STI
+	select DMA_ENGINE
+	select FW_LOADER
+	select FW_LOADER_USER_HELPER_FALLBACK
+	select LIBELF_32
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for ST FDMA controller.
+	  It supports 16 independent DMA channels, accepts up to 32 DMA requests
+
+	  Say Y here if you have such a chipset.
+	  If unsure, say N.
+
 endif
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 6a4d6f2..f68e6d8 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
 obj-$(CONFIG_FSL_RAID) += fsl_raid.o
 obj-$(CONFIG_FSL_EDMA) += fsl-edma.o
 obj-$(CONFIG_QCOM_BAM_DMA) += qcom_bam_dma.o
+obj-$(CONFIG_ST_FDMA) += st_fdma.o
 obj-y += xilinx/
 obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
 obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
diff --git a/drivers/dma/st_fdma.c b/drivers/dma/st_fdma.c
new file mode 100644
index 0000000..07a6df1
--- /dev/null
+++ b/drivers/dma/st_fdma.c
@@ -0,0 +1,1182 @@
+/*
+ * st_fdma.c
+ *
+ * Copyright (C) 2014 STMicroelectronics
+ * Author: Ludovic Barre <Ludovic.barre@xxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/firmware.h>
+#include <linux/elf.h>
+#include <linux/atomic.h>
+
+#include "st_fdma.h"
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+static char *fdma_clk_name[CLK_MAX_NUM] = {
+	[CLK_SLIM]	= "fdma_slim",
+	[CLK_HI]	= "fdma_hi",
+	[CLK_LOW]	= "fdma_low",
+	[CLK_IC]	= "fdma_ic",
+};
+
+static int st_fdma_clk_get(struct st_fdma_dev *fdev)
+{
+	int i;
+
+	for (i = 0; i < CLK_MAX_NUM; i++) {
+		fdev->clks[i] = devm_clk_get(fdev->dev, fdma_clk_name[i]);
+		if (IS_ERR(fdev->clks[i])) {
+			dev_err(fdev->dev,
+				"failed to get clock: %s\n", fdma_clk_name[i]);
+			return PTR_ERR(fdev->clks[i]);
+		}
+	}
+
+	if (i != CLK_MAX_NUM) {
+		dev_err(fdev->dev, "all clocks are not defined\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int st_fdma_clk_enable(struct st_fdma_dev *fdev)
+{
+	int i, ret;
+
+	for (i = 0; i < CLK_MAX_NUM; i++) {
+		ret = clk_prepare_enable(fdev->clks[i]);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void st_fdma_clk_disable(struct st_fdma_dev *fdev)
+{
+	int i;
+
+	for (i = 0; i < CLK_MAX_NUM; i++)
+		clk_disable_unprepare(fdev->clks[i]);
+}
+
+static inline struct st_fdma_chan *to_st_fdma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct st_fdma_chan, vchan.chan);
+}
+
+static struct st_fdma_desc *to_st_fdma_desc(struct virt_dma_desc *vd)
+{
+	return container_of(vd, struct st_fdma_desc, vdesc);
+}
+
+void *st_fdma_seg_to_mem(struct st_fdma_dev *fdev, u64 da, int len)
+{
+	int i;
+	resource_size_t base = fdev->io_res->start;
+	const struct st_fdma_ram *fdma_mem = fdev->drvdata->fdma_mem;
+	void *ptr = NULL;
+
+	for (i = 0; i < fdev->drvdata->num_mem; i++) {
+		int mem_off = da - (base + fdma_mem[i].offset);
+
+		/* next mem if da is too small */
+		if (mem_off < 0)
+			continue;
+
+		/* next mem if da is too large */
+		if (mem_off + len > fdma_mem[i].size)
+			continue;
+
+		ptr = fdev->io_base + fdma_mem[i].offset + mem_off;
+		break;
+	}
+
+	return ptr;
+}
+
+static int
+st_fdma_elf_sanity_check(struct st_fdma_dev *fdev, const struct firmware *fw)
+{
+	const char *fw_name = fdev->pdata->fw_name;
+	struct elf32_hdr *ehdr;
+	char class;
+
+	if (!fw) {
+		dev_err(fdev->dev, "failed to load %s\n", fw_name);
+		return -EINVAL;
+	}
+
+	if (fw->size < sizeof(struct elf32_hdr)) {
+		dev_err(fdev->dev, "Image is too small\n");
+		return -EINVAL;
+	}
+
+	ehdr = (struct elf32_hdr *)fw->data;
+
+	/* We only support ELF32 at this point */
+	class = ehdr->e_ident[EI_CLASS];
+	if (class != ELFCLASS32) {
+		dev_err(fdev->dev, "Unsupported class: %d\n", class);
+		return -EINVAL;
+	}
+
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
+		dev_err(fdev->dev, "Unsupported firmware endianness\n");
+		return -EINVAL;
+	}
+
+	if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
+		dev_err(fdev->dev, "Image is too small\n");
+		return -EINVAL;
+	}
+
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
+		dev_err(fdev->dev, "Image is corrupted (bad magic)\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_phnum != fdev->drvdata->num_mem) {
+		dev_err(fdev->dev, "spurious nb of segments\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_type != ET_EXEC) {
+		dev_err(fdev->dev, "Unsupported ELF header type\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_machine != EM_SLIM) {
+		dev_err(fdev->dev, "Unsupported ELF header machine\n");
+		return -EINVAL;
+	}
+	if (ehdr->e_phoff > fw->size) {
+		dev_err(fdev->dev, "Firmware size is too small\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+st_fdma_elf_load_segments(struct st_fdma_dev *fdev, const struct firmware *fw)
+{
+	struct device *dev = fdev->dev;
+	struct elf32_hdr *ehdr;
+	struct elf32_phdr *phdr;
+	int i, mem_loaded = 0;
+	const u8 *elf_data = fw->data;
+
+	ehdr = (struct elf32_hdr *)elf_data;
+	phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
+
+	/*
+	 * go through the available ELF segments
+	 * the program header's paddr member to contain device addresses.
+	 * We then go through the physically contiguous memory regions which we
+	 * allocated (and mapped) earlier on the probe,
+	 * and "translate" device address to kernel addresses,
+	 * so we can copy the segments where they are expected.
+	 */
+	for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+		u32 da = phdr->p_paddr;
+		u32 memsz = phdr->p_memsz;
+		u32 filesz = phdr->p_filesz;
+		u32 offset = phdr->p_offset;
+		void *dst;
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		dev_dbg(dev, "phdr: type %d da %#x ofst:%#x memsz %#x filesz %#x\n",
+			phdr->p_type, da, offset, memsz, filesz);
+
+		if (filesz > memsz) {
+			dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
+				filesz, memsz);
+			break;
+		}
+
+		if (offset + filesz > fw->size) {
+			dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
+				offset + filesz, fw->size);
+			break;
+		}
+
+		dst = st_fdma_seg_to_mem(fdev, da, memsz);
+		if (!dst) {
+			dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
+			break;
+		}
+
+		if (phdr->p_filesz)
+			memcpy(dst, elf_data + phdr->p_offset, filesz);
+
+		if (memsz > filesz)
+			memset(dst + filesz, 0, memsz - filesz);
+
+		mem_loaded++;
+	}
+
+	return (mem_loaded != fdev->drvdata->num_mem) ? -EINVAL : 0;
+}
+
+static void st_fdma_enable(struct st_fdma_dev *fdev)
+{
+	unsigned long hw_id, hw_ver, fw_rev;
+	u32 val;
+
+	/* disable CPU pipeline clock & reset cpu pipeline */
+	val = FDMA_CLK_GATE_DIS | FDMA_CLK_GATE_RESET;
+	fdma_write(fdev, val, CLK_GATE);
+	/* disable SLIM core STBus sync */
+	fdma_write(fdev, FDMA_STBUS_SYNC_DIS, STBUS_SYNC);
+	/* enable cpu pipeline clock */
+	fdma_write(fdev, !FDMA_CLK_GATE_DIS, CLK_GATE);
+
+	/* clear int & cmd mailbox */
+	fdma_write(fdev, ~0UL, INT_CLR);
+	fdma_write(fdev, ~0UL, CMD_CLR);
+	/* enable all channels cmd & int */
+	fdma_write(fdev, ~0UL, INT_MASK);
+	fdma_write(fdev, ~0UL, CMD_MASK);
+
+	/* enable cpu */
+	writel(FDMA_EN_RUN, fdev->io_base + FDMA_EN_OFST);
+
+	hw_id = fdma_read(fdev, ID);
+	hw_ver = fdma_read(fdev, VER);
+	fw_rev = fdma_read(fdev, REV_ID);
+
+	dev_info(fdev->dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
+		 FDMA_REV_ID_MAJ(fw_rev), FDMA_REV_ID_MIN(fw_rev),
+		 hw_id, hw_ver);
+}
+
+static int st_fdma_disable(struct st_fdma_dev *fdev)
+{
+	/* mask all (cmd & int) channels */
+	fdma_write(fdev, 0UL, INT_MASK);
+	fdma_write(fdev, 0UL, CMD_MASK);
+
+	/* disable cpu pipeline clock */
+	fdma_write(fdev, FDMA_CLK_GATE_DIS, CLK_GATE);
+	writel(!FDMA_EN_RUN, fdev->io_base + FDMA_EN_OFST);
+
+	return readl(fdev->io_base + FDMA_EN_OFST);
+}
+
+static void st_fdma_fw_cb(const struct firmware *fw, void *context)
+{
+	struct st_fdma_dev *fdev = context;
+	int ret;
+
+	ret = st_fdma_elf_sanity_check(fdev, fw);
+	if (ret)
+		goto out;
+
+	st_fdma_disable(fdev);
+	ret = st_fdma_elf_load_segments(fdev, fw);
+	if (ret)
+		goto out;
+
+	st_fdma_enable(fdev);
+	atomic_set(&fdev->fw_loaded, 1);
+out:
+	release_firmware(fw);
+	complete_all(&fdev->fw_ack);
+}
+
+static int st_fdma_get_fw(struct st_fdma_dev *fdev)
+{
+	int ret;
+
+	init_completion(&fdev->fw_ack);
+	atomic_set(&fdev->fw_loaded, 0);
+
+	ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
+				      fdev->pdata->fw_name, fdev->dev,
+				      GFP_KERNEL, fdev, st_fdma_fw_cb);
+	if (ret) {
+		dev_err(fdev->dev, "request_firmware_nowait err: %d\n", ret);
+		complete_all(&fdev->fw_ack);
+	}
+
+	return ret;
+}
+
+static int st_fdma_dreq_get(struct st_fdma_chan *fchan)
+{
+	struct st_fdma_dev *fdev = fchan->fdev;
+	u32 req_line_cfg = fchan->cfg.req_line;
+	u32 dreq_line;
+	int try = 0;
+
+	/*
+	 * dreq_mask is shared for n channels of fdma, so all accesses must be
+	 * atomic. if the dreq_mask it change between ffz ant set_bit,
+	 * we retry
+	 */
+	do {
+		if (fdev->dreq_mask == ~0L) {
+			dev_err(fdev->dev, "No req lines available\n");
+			return -EINVAL;
+		}
+
+		if (try || req_line_cfg >= ST_FDMA_NR_DREQS) {
+			dev_err(fdev->dev, "Invalid or used req line\n");
+			return -EINVAL;
+		} else {
+			dreq_line = req_line_cfg;
+		}
+
+		try++;
+	} while (test_and_set_bit(dreq_line, &fdev->dreq_mask));
+
+	dev_dbg(fdev->dev, "get dreq_line:%d mask:%#lx\n",
+		dreq_line, fdev->dreq_mask);
+
+	return dreq_line;
+}
+
+static void st_fdma_dreq_put(struct st_fdma_chan *fchan)
+{
+	struct st_fdma_dev *fdev = fchan->fdev;
+
+	dev_dbg(fdev->dev, "put dreq_line:%#x\n", fchan->dreq_line);
+	clear_bit(fchan->dreq_line, &fdev->dreq_mask);
+}
+
+static void st_fdma_xfer_desc(struct st_fdma_chan *fchan)
+{
+	struct virt_dma_desc *vdesc;
+	unsigned long nbytes, ch_cmd, cmd;
+
+	vdesc = vchan_next_desc(&fchan->vchan);
+	if (!vdesc)
+		return;
+
+	fchan->fdesc = to_st_fdma_desc(vdesc);
+	nbytes = fchan->fdesc->node[0].desc->nbytes;
+	cmd = FDMA_CMD_START(fchan->vchan.chan.chan_id);
+	ch_cmd = fchan->fdesc->node[0].pdesc | FDMA_CH_CMD_STA_START;
+
+	/* start the channel for the descriptor */
+	fnode_write(fchan, nbytes, CNTN);
+	fchan_write(fchan, ch_cmd, CH_CMD);
+	writel(cmd, fchan->fdev->io_base + FDMA_CMD_SET_OFST);
+
+	dev_dbg(fchan->fdev->dev, "start chan:%d\n", fchan->vchan.chan.chan_id);
+}
+
+static void st_fdma_ch_sta_update(struct st_fdma_chan *fchan,
+				  unsigned long int_sta)
+{
+	unsigned long ch_sta, ch_err;
+	int ch_id = fchan->vchan.chan.chan_id;
+	struct st_fdma_dev *fdev = fchan->fdev;
+
+	ch_sta = fchan_read(fchan, CH_CMD);
+	ch_err = ch_sta & FDMA_CH_CMD_ERR_MASK;
+	ch_sta &= FDMA_CH_CMD_STA_MASK;
+
+	if (int_sta & FDMA_INT_STA_ERR) {
+		dev_warn(fdev->dev, "chan:%d, error:%ld\n", ch_id, ch_err);
+		fchan->status = DMA_ERROR;
+		return;
+	}
+
+	switch (ch_sta) {
+	case FDMA_CH_CMD_STA_PAUSED:
+		fchan->status = DMA_PAUSED;
+		break;
+	case FDMA_CH_CMD_STA_RUNNING:
+		fchan->status = DMA_IN_PROGRESS;
+		break;
+	}
+}
+
+static irqreturn_t st_fdma_irq_handler(int irq, void *dev_id)
+{
+	struct st_fdma_dev *fdev = dev_id;
+	irqreturn_t ret = IRQ_NONE;
+	struct st_fdma_chan *fchan = &fdev->chans[0];
+	unsigned long int_sta, clr;
+
+	int_sta = fdma_read(fdev, INT_STA);
+	clr = int_sta;
+
+	for (; int_sta != 0 ; int_sta >>= 2, fchan++) {
+		if (!(int_sta & (FDMA_INT_STA_CH | FDMA_INT_STA_ERR)))
+			continue;
+
+		spin_lock(&fchan->vchan.lock);
+		st_fdma_ch_sta_update(fchan, int_sta);
+
+		if (fchan->fdesc) {
+			if (!fchan->fdesc->iscyclic) {
+				list_del(&fchan->fdesc->vdesc.node);
+				vchan_cookie_complete(&fchan->fdesc->vdesc);
+				fchan->fdesc = NULL;
+				fchan->status = DMA_COMPLETE;
+			} else {
+				vchan_cyclic_callback(&fchan->fdesc->vdesc);
+			}
+
+			/* Start the next descriptor (if available) */
+			if (!fchan->fdesc)
+				st_fdma_xfer_desc(fchan);
+		}
+
+		spin_unlock(&fchan->vchan.lock);
+		ret = IRQ_HANDLED;
+	}
+
+	fdma_write(fdev, clr, INT_CLR);
+
+	return ret;
+}
+
+static struct dma_chan *st_fdma_of_xlate(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	struct st_fdma_dev *fdev = ofdma->of_dma_data;
+	struct st_fdma_cfg cfg;
+
+	if (dma_spec->args_count < 1)
+		return NULL;
+
+	cfg.of_node = dma_spec->np;
+	cfg.req_line = dma_spec->args[0];
+	cfg.req_ctrl = 0;
+	cfg.type = ST_FDMA_TYPE_FREE_RUN;
+
+	if (dma_spec->args_count > 1)
+		cfg.req_ctrl = dma_spec->args[1] & REQ_CTRL_CFG_MASK;
+
+	if (dma_spec->args_count > 2)
+		cfg.type = dma_spec->args[2];
+
+	dev_dbg(fdev->dev, "xlate req_line:%d type:%d req_ctrl:%#x\n",
+		cfg.req_line, cfg.type, cfg.req_ctrl);
+
+	return dma_request_channel(fdev->dma_device.cap_mask,
+			st_fdma_filter_fn, &cfg);
+}
+
+static void st_fdma_free_desc(struct virt_dma_desc *vdesc)
+{
+	struct st_fdma_desc *fdesc;
+	int i;
+
+	fdesc = to_st_fdma_desc(vdesc);
+	for (i = 0; i < fdesc->n_nodes; i++)
+			dma_pool_free(fdesc->fchan->node_pool,
+				      fdesc->node[i].desc,
+				      fdesc->node[i].pdesc);
+	kfree(fdesc);
+}
+
+static struct st_fdma_desc *st_fdma_alloc_desc(struct st_fdma_chan *fchan,
+					       int sg_len)
+{
+	struct st_fdma_desc *fdesc;
+	int i;
+
+	fdesc = kzalloc(sizeof(*fdesc) +
+			sizeof(struct st_fdma_sw_node) * sg_len, GFP_NOWAIT);
+	if (!fdesc)
+		return NULL;
+
+	fdesc->fchan = fchan;
+	fdesc->n_nodes = sg_len;
+	for (i = 0; i < sg_len; i++) {
+		fdesc->node[i].desc = dma_pool_alloc(fchan->node_pool,
+				GFP_NOWAIT, &fdesc->node[i].pdesc);
+		if (!fdesc->node[i].desc)
+			goto err;
+	}
+	return fdesc;
+
+err:
+	while (--i >= 0)
+		dma_pool_free(fchan->node_pool, fdesc->node[i].desc,
+			      fdesc->node[i].pdesc);
+	kfree(fdesc);
+	return NULL;
+}
+
+static int st_fdma_alloc_chan_res(struct dma_chan *chan)
+{
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+
+	if (fchan->cfg.type == ST_FDMA_TYPE_FREE_RUN) {
+		fchan->dreq_line = 0;
+	} else {
+		fchan->dreq_line = st_fdma_dreq_get(fchan);
+		if (IS_ERR_VALUE(fchan->dreq_line))
+			return -EINVAL;
+	}
+
+	/* Create the dma pool for descriptor allocation */
+	fchan->node_pool = dmam_pool_create(dev_name(&chan->dev->device),
+					    fchan->fdev->dev,
+					    sizeof(struct st_fdma_hw_node),
+					    __alignof__(struct st_fdma_hw_node),
+					    0);
+
+	if (!fchan->node_pool) {
+		dev_err(fchan->fdev->dev, "unable to allocate desc pool\n");
+		return -ENOMEM;
+	}
+
+	dev_dbg(fchan->fdev->dev, "alloc ch_id:%d type:%d\n",
+		fchan->vchan.chan.chan_id, fchan->cfg.type);
+
+	return 0;
+}
+
+static void st_fdma_free_chan_res(struct dma_chan *chan)
+{
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	dev_dbg(fchan->fdev->dev, "freeing chan:%d\n",
+		fchan->vchan.chan.chan_id);
+
+	if (fchan->cfg.type != ST_FDMA_TYPE_FREE_RUN)
+		st_fdma_dreq_put(fchan);
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+	fchan->fdesc = NULL;
+	vchan_get_all_descriptors(&fchan->vchan, &head);
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+
+	dma_pool_destroy(fchan->node_pool);
+	fchan->node_pool = NULL;
+	memset(&fchan->cfg, 0, sizeof(struct st_fdma_cfg));
+}
+
+static struct dma_async_tx_descriptor *st_fdma_prep_dma_memcpy(
+	struct dma_chan *chan,	dma_addr_t dst, dma_addr_t src,
+	size_t len, unsigned long flags)
+{
+	struct st_fdma_chan *fchan;
+	struct st_fdma_desc *fdesc;
+	struct st_fdma_hw_node *hw_node;
+
+	if (!len)
+		return NULL;
+
+	fchan = to_st_fdma_chan(chan);
+
+	if (!atomic_read(&fchan->fdev->fw_loaded)) {
+		dev_err(fchan->fdev->dev, "%s: fdma fw not loaded\n", __func__);
+		return NULL;
+	}
+
+	/* We only require a single descriptor */
+	fdesc = st_fdma_alloc_desc(fchan, 1);
+	if (!fdesc) {
+		dev_err(fchan->fdev->dev, "no memory for desc\n");
+		return NULL;
+	}
+
+	hw_node = fdesc->node[0].desc;
+	hw_node->next = 0;
+	hw_node->control = NODE_CTRL_REQ_MAP_FREE_RUN;
+	hw_node->control |= NODE_CTRL_SRC_INCR;
+	hw_node->control |= NODE_CTRL_DST_INCR;
+	hw_node->control |= NODE_CTRL_INT_EON;
+	hw_node->nbytes = len;
+	hw_node->saddr = src;
+	hw_node->daddr = dst;
+	hw_node->generic.length = len;
+	hw_node->generic.sstride = 0;
+	hw_node->generic.dstride = 0;
+
+	return vchan_tx_prep(&fchan->vchan, &fdesc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *st_fdma_prep_dma_cyclic(
+		struct dma_chan *chan, dma_addr_t buf_addr, size_t len,
+		size_t period_len, enum dma_transfer_direction direction,
+		unsigned long flags)
+{
+	struct st_fdma_chan *fchan;
+	struct st_fdma_desc *fdesc;
+	int sg_len, i;
+
+	if (!chan || !len || !period_len)
+		return NULL;
+
+	fchan = to_st_fdma_chan(chan);
+
+	if (!atomic_read(&fchan->fdev->fw_loaded)) {
+		dev_err(fchan->fdev->dev, "%s: fdma fw not loaded\n", __func__);
+		return NULL;
+	}
+
+	if (!is_slave_direction(direction)) {
+		dev_err(fchan->fdev->dev, "bad direction?\n");
+		return NULL;
+	}
+
+	/* the buffer length must be a multiple of period_len */
+	if (len % period_len != 0) {
+		dev_err(fchan->fdev->dev, "len is not multiple of period\n");
+		return NULL;
+	}
+
+	sg_len = len / period_len;
+	fdesc = st_fdma_alloc_desc(fchan, sg_len);
+	if (!fdesc) {
+		dev_err(fchan->fdev->dev, "no memory for desc\n");
+		return NULL;
+	}
+
+	fdesc->iscyclic = true;
+
+	for (i = 0; i < sg_len; i++) {
+		struct st_fdma_hw_node *hw_node = fdesc->node[i].desc;
+
+		hw_node->next = fdesc->node[(i + 1) % sg_len].pdesc;
+
+		hw_node->control = NODE_CTRL_REQ_MAP_DREQ(fchan->dreq_line);
+		hw_node->control |= NODE_CTRL_INT_EON;
+
+		if (direction == DMA_MEM_TO_DEV) {
+			hw_node->control |= NODE_CTRL_SRC_INCR;
+			hw_node->control |= NODE_CTRL_DST_STATIC;
+			hw_node->saddr = buf_addr + (i * period_len);
+			hw_node->daddr = fchan->cfg.dev_addr;
+		} else {
+			hw_node->control |= NODE_CTRL_SRC_STATIC;
+			hw_node->control |= NODE_CTRL_DST_INCR;
+			hw_node->saddr = fchan->cfg.dev_addr;
+			hw_node->daddr = buf_addr + (i * period_len);
+		}
+
+		hw_node->nbytes = period_len;
+		hw_node->generic.length = period_len;
+		hw_node->generic.sstride = 0;
+		hw_node->generic.dstride = 0;
+	}
+
+	return vchan_tx_prep(&fchan->vchan, &fdesc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *st_fdma_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
+{
+	struct st_fdma_chan *fchan;
+	struct st_fdma_desc *fdesc;
+	struct st_fdma_hw_node *hw_node;
+	struct scatterlist *sg;
+	int i;
+
+	if (!chan || !sgl || !sg_len)
+		return NULL;
+
+	fchan = to_st_fdma_chan(chan);
+
+	if (!atomic_read(&fchan->fdev->fw_loaded)) {
+		dev_err(fchan->fdev->dev, "%s: fdma fw not loaded\n", __func__);
+		return NULL;
+	}
+
+	if (!is_slave_direction(direction)) {
+		dev_err(fchan->fdev->dev, "bad direction?\n");
+		return NULL;
+	}
+
+	fdesc = st_fdma_alloc_desc(fchan, sg_len);
+	if (!fdesc) {
+		dev_err(fchan->fdev->dev, "no memory for desc\n");
+		return NULL;
+	}
+
+	fdesc->iscyclic = false;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		hw_node = fdesc->node[i].desc;
+
+		hw_node->next = fdesc->node[(i + 1) % sg_len].pdesc;
+		hw_node->control = NODE_CTRL_REQ_MAP_DREQ(fchan->dreq_line);
+
+		if (direction == DMA_MEM_TO_DEV) {
+			hw_node->control |= NODE_CTRL_SRC_INCR;
+			hw_node->control |= NODE_CTRL_DST_STATIC;
+			hw_node->saddr = sg_dma_address(sg);
+			hw_node->daddr = fchan->cfg.dev_addr;
+		} else {
+			hw_node->control |= NODE_CTRL_SRC_STATIC;
+			hw_node->control |= NODE_CTRL_DST_INCR;
+			hw_node->saddr = fchan->cfg.dev_addr;
+			hw_node->daddr = sg_dma_address(sg);
+		}
+
+		hw_node->nbytes = sg_dma_len(sg);
+		hw_node->generic.length = sg_dma_len(sg);
+		hw_node->generic.sstride = 0;
+		hw_node->generic.dstride = 0;
+	}
+	/* interrupt at end of last node */
+	hw_node->control |= NODE_CTRL_INT_EON;
+
+	return vchan_tx_prep(&fchan->vchan, &fdesc->vdesc, flags);
+}
+
+static size_t st_fdma_desc_residue(struct st_fdma_chan *fchan,
+				   struct virt_dma_desc *vdesc,
+				   bool in_progress)
+{
+	struct st_fdma_desc *fdesc = fchan->fdesc;
+	size_t residue = 0;
+	dma_addr_t cur_addr = 0;
+	int i;
+
+	if (in_progress) {
+		cur_addr = fchan_read(fchan, CH_CMD);
+		cur_addr &= FDMA_CH_CMD_DATA_MASK;
+	}
+
+	for (i = fchan->fdesc->n_nodes - 1 ; i >= 0; i--) {
+		if (cur_addr == fdesc->node[i].pdesc) {
+			residue += fnode_read(fchan, CNTN);
+			break;
+		}
+		residue += fdesc->node[i].desc->nbytes;
+	}
+
+	return residue;
+}
+
+static enum dma_status st_fdma_tx_status(struct dma_chan *chan,
+					 dma_cookie_t cookie,
+					 struct dma_tx_state *txstate)
+{
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	struct virt_dma_desc *vd;
+	enum dma_status ret;
+	unsigned long flags;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (ret == DMA_COMPLETE)
+		return ret;
+
+	if (!txstate)
+		return fchan->status;
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+	vd = vchan_find_desc(&fchan->vchan, cookie);
+	if (fchan->fdesc && cookie == fchan->fdesc->vdesc.tx.cookie)
+		txstate->residue = st_fdma_desc_residue(fchan, vd, true);
+	else if (vd)
+		txstate->residue = st_fdma_desc_residue(fchan, vd, false);
+	else
+		txstate->residue = 0;
+
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+
+	return fchan->status;
+}
+
+static void st_fdma_issue_pending(struct dma_chan *chan)
+{
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+
+	if (vchan_issue_pending(&fchan->vchan) && !fchan->fdesc)
+		st_fdma_xfer_desc(fchan);
+
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+}
+
+static int st_fdma_pause(struct dma_chan *chan)
+{
+	unsigned long flags;
+	LIST_HEAD(head);
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	int ch_id = fchan->vchan.chan.chan_id;
+	unsigned long cmd = FDMA_CMD_PAUSE(ch_id);
+
+	dev_dbg(fchan->fdev->dev, "pause chan:%d\n", ch_id);
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+	if (fchan->fdesc)
+		fdma_write(fchan->fdev, cmd, CMD_SET);
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+
+	return 0;
+}
+
+static int st_fdma_resume(struct dma_chan *chan)
+{
+	unsigned long flags;
+	unsigned long val;
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	int ch_id = fchan->vchan.chan.chan_id;
+
+	dev_dbg(fchan->fdev->dev, "resume chan:%d\n", ch_id);
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+	if (fchan->fdesc) {
+		val = fchan_read(fchan, CH_CMD);
+		val &= FDMA_CH_CMD_DATA_MASK;
+		fchan_write(fchan, val, CH_CMD);
+	}
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+
+	return 0;
+}
+
+static int st_fdma_terminate_all(struct dma_chan *chan)
+{
+	unsigned long flags;
+	LIST_HEAD(head);
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	int ch_id = fchan->vchan.chan.chan_id;
+	unsigned long cmd = FDMA_CMD_PAUSE(ch_id);
+
+	dev_dbg(fchan->fdev->dev, "terminate chan:%d\n", ch_id);
+
+	spin_lock_irqsave(&fchan->vchan.lock, flags);
+	fdma_write(fchan->fdev, cmd, CMD_SET);
+	fchan->fdesc = NULL;
+	vchan_get_all_descriptors(&fchan->vchan, &head);
+	spin_unlock_irqrestore(&fchan->vchan.lock, flags);
+	vchan_dma_desc_free_list(&fchan->vchan, &head);
+
+	return 0;
+}
+
+static int st_fdma_slave_config(struct dma_chan *chan,
+				struct dma_slave_config *slave_cfg)
+{
+	u32 maxburst = 0, addr = 0;
+	enum dma_slave_buswidth width;
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+	int ch_id = fchan->vchan.chan.chan_id;
+	struct st_fdma_dev *fdev = fchan->fdev;
+
+	if (slave_cfg->direction == DMA_DEV_TO_MEM) {
+		fchan->cfg.req_ctrl &= ~REQ_CTRL_WNR;
+		maxburst = slave_cfg->src_maxburst;
+		width = slave_cfg->src_addr_width;
+		addr = slave_cfg->src_addr;
+	} else if (slave_cfg->direction == DMA_MEM_TO_DEV) {
+		fchan->cfg.req_ctrl |= REQ_CTRL_WNR;
+		maxburst = slave_cfg->dst_maxburst;
+		width = slave_cfg->dst_addr_width;
+		addr = slave_cfg->dst_addr;
+	} else {
+		return -EINVAL;
+	}
+
+	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
+		fchan->cfg.req_ctrl |= REQ_CTRL_OPCODE_LD_ST1;
+	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
+		fchan->cfg.req_ctrl |= REQ_CTRL_OPCODE_LD_ST2;
+	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
+		fchan->cfg.req_ctrl |= REQ_CTRL_OPCODE_LD_ST4;
+	else if (width == DMA_SLAVE_BUSWIDTH_8_BYTES)
+		fchan->cfg.req_ctrl |= REQ_CTRL_OPCODE_LD_ST8;
+	else
+		return -EINVAL;
+
+	fchan->cfg.req_ctrl |= REQ_CTRL_NUM_OPS(maxburst-1);
+	dreq_write(fchan, fchan->cfg.req_ctrl, REQ_CTRL);
+
+	fchan->cfg.dev_addr = addr;
+	fchan->cfg.dir = slave_cfg->direction;
+
+	dev_dbg(fdev->dev, "chan:%d dma_slave_config addr:%#x req_ctrl:%#x\n",
+		ch_id, addr, fchan->cfg.req_ctrl);
+
+	return 0;
+}
+
+static const struct st_fdma_ram fdma_mpe31_mem[] = {
+	{ .name = "dmem", .offset = 0x10000, .size = 0x3000 },
+	{ .name = "imem", .offset = 0x18000, .size = 0x8000 },
+};
+
+static const struct st_fdma_driverdata fdma_mpe31 = {
+	.fdma_mem = fdma_mpe31_mem,
+	.num_mem = ARRAY_SIZE(fdma_mpe31_mem),
+};
+
+static const struct of_device_id st_fdma_match[] = {
+	{ .compatible = "st,fdma_mpe31", .data = &fdma_mpe31 },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_fdma_match);
+
+static struct st_fdma_platform_data *
+st_fdma_parse_dt(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct st_fdma_platform_data *pdata;
+	int ret;
+
+	if (!np)
+		goto err;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		goto err;
+
+	ret = of_property_read_u32(np, "dma-channels", &pdata->nr_channels);
+	if (ret)
+		goto err;
+
+	ret = of_property_read_string(np, "st,fw-name", &pdata->fw_name);
+	if (ret)
+		goto err;
+
+	return pdata;
+
+err:
+	return NULL;
+}
+#define FDMA_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+				 BIT(DMA_SLAVE_BUSWIDTH_3_BYTES) | \
+				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
+
+
+static int st_fdma_probe(struct platform_device *pdev)
+{
+	struct st_fdma_dev *fdev;
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	const struct st_fdma_driverdata *drvdata;
+	const struct st_fdma_platform_data *pdata;
+	int irq, ret, i;
+
+	match = of_match_device((st_fdma_match), &pdev->dev);
+	if (!match || !match->data) {
+		dev_err(&pdev->dev, "No device match found\n");
+		return -ENODEV;
+	}
+
+	drvdata = match->data;
+
+	pdata = st_fdma_parse_dt(pdev);
+	if (!pdata) {
+		dev_err(&pdev->dev, "unable to find platform data\n");
+		return -EINVAL;
+	}
+
+	fdev = devm_kzalloc(&pdev->dev, sizeof(*fdev), GFP_KERNEL);
+	if (!fdev)
+		return -ENOMEM;
+
+	fdev->chans = devm_kzalloc(&pdev->dev,
+				   pdata->nr_channels
+				   * sizeof(struct st_fdma_chan), GFP_KERNEL);
+	if (!fdev->chans)
+		return -ENOMEM;
+
+	fdev->dev = &pdev->dev;
+	fdev->drvdata = drvdata;
+	fdev->pdata = pdata;
+	platform_set_drvdata(pdev, fdev);
+
+	fdev->io_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fdev->io_base = devm_ioremap_resource(&pdev->dev, fdev->io_res);
+	if (IS_ERR(fdev->io_base))
+		return PTR_ERR(fdev->io_base);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Failed to get irq resource\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, st_fdma_irq_handler, 0,
+			       dev_name(&pdev->dev), fdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq\n");
+		goto err;
+	}
+
+	ret = st_fdma_clk_get(fdev);
+	if (ret)
+		goto err;
+
+	ret = st_fdma_clk_enable(fdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable clocks\n");
+		goto err_clk;
+	}
+
+	/* Initialise list of FDMA channels */
+	INIT_LIST_HEAD(&fdev->dma_device.channels);
+	for (i = 0; i < fdev->pdata->nr_channels; i++) {
+		struct st_fdma_chan *fchan = &fdev->chans[i];
+
+		fchan->fdev = fdev;
+		fchan->vchan.desc_free = st_fdma_free_desc;
+		vchan_init(&fchan->vchan, &fdev->dma_device);
+	}
+
+	ret = st_fdma_get_fw(fdev);
+	if (ret)
+		goto err_clk;
+
+	/* Initialise the FDMA dreq (reserve 0 & 31 for FDMA use) */
+	fdev->dreq_mask = BIT(0) | BIT(31);
+
+	dma_cap_set(DMA_SLAVE, fdev->dma_device.cap_mask);
+	dma_cap_set(DMA_CYCLIC, fdev->dma_device.cap_mask);
+	dma_cap_set(DMA_MEMCPY, fdev->dma_device.cap_mask);
+
+	fdev->dma_device.dev = &pdev->dev;
+	fdev->dma_device.device_alloc_chan_resources = st_fdma_alloc_chan_res;
+	fdev->dma_device.device_free_chan_resources = st_fdma_free_chan_res;
+	fdev->dma_device.device_prep_dma_cyclic	= st_fdma_prep_dma_cyclic;
+	fdev->dma_device.device_prep_slave_sg = st_fdma_prep_slave_sg;
+	fdev->dma_device.device_prep_dma_memcpy = st_fdma_prep_dma_memcpy;
+	fdev->dma_device.device_tx_status = st_fdma_tx_status;
+	fdev->dma_device.device_issue_pending = st_fdma_issue_pending;
+	fdev->dma_device.device_terminate_all = st_fdma_terminate_all;
+	fdev->dma_device.device_config = st_fdma_slave_config;
+	fdev->dma_device.device_pause = st_fdma_pause;
+	fdev->dma_device.device_resume = st_fdma_resume;
+
+	fdev->dma_device.src_addr_widths = FDMA_DMA_BUSWIDTHS;
+	fdev->dma_device.dst_addr_widths = FDMA_DMA_BUSWIDTHS;
+	fdev->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	fdev->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+	ret = dma_async_device_register(&fdev->dma_device);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register DMA device\n");
+		goto err_clk;
+	}
+
+	ret = of_dma_controller_register(np, st_fdma_of_xlate, fdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register controller\n");
+		goto err_dma_dev;
+	}
+
+	dev_info(&pdev->dev, "ST FDMA engine driver, irq:%d\n", irq);
+
+	return 0;
+
+err_dma_dev:
+	dma_async_device_unregister(&fdev->dma_device);
+err_clk:
+	st_fdma_clk_disable(fdev);
+err:
+	return ret;
+}
+
+static int __exit st_fdma_remove(struct platform_device *pdev)
+{
+	struct st_fdma_dev *fdev = platform_get_drvdata(pdev);
+
+	wait_for_completion(&fdev->fw_ack);
+
+	st_fdma_clk_disable(fdev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int st_fdma_pm_suspend(struct device *dev)
+{
+	struct st_fdma_dev *fdev = dev_get_drvdata(dev);
+	int ret;
+
+	if (atomic_read(&fdev->fw_loaded)) {
+		ret = st_fdma_disable(fdev);
+		if (ret & FDMA_EN_RUN) {
+			dev_warn(fdev->dev, "Failed to disable channels");
+			return -EBUSY;
+		}
+	}
+
+	st_fdma_clk_disable(fdev);
+
+	return 0;
+}
+
+static int st_fdma_pm_resume(struct device *dev)
+{
+	struct st_fdma_dev *fdev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = st_fdma_clk_enable(fdev);
+	if (ret) {
+		dev_err(fdev->dev, "Failed to enable clocks\n");
+		goto out;
+	}
+
+	ret = st_fdma_get_fw(fdev);
+out:
+	return ret;
+}
+
+const struct dev_pm_ops st_fdma_pm = {
+	.suspend_late = st_fdma_pm_suspend,
+	.resume_early = st_fdma_pm_resume,
+};
+
+#define ST_FDMA_PM	(&st_fdma_pm)
+#else
+#define ST_FDMA_PM	NULL
+#endif
+
+static struct platform_driver st_fdma_platform_driver = {
+	.driver = {
+		.name = "st-fdma",
+		.of_match_table = st_fdma_match,
+		.pm = ST_FDMA_PM,
+	},
+	.probe = st_fdma_probe,
+	.remove = st_fdma_remove,
+};
+module_platform_driver(st_fdma_platform_driver);
+
+bool st_fdma_filter_fn(struct dma_chan *chan, void *param)
+{
+	struct st_fdma_cfg *config = param;
+	struct st_fdma_chan *fchan = to_st_fdma_chan(chan);
+
+	if (!param)
+		return false;
+
+	if (fchan->fdev->dma_device.dev->of_node != config->of_node)
+		return false;
+
+	fchan->cfg = *config;
+
+	return true;
+}
+EXPORT_SYMBOL(st_fdma_filter_fn);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("STMicroelectronics FDMA engine driver");
+MODULE_AUTHOR("Ludovic.barre <Ludovic.barre@xxxxxx>");
diff --git a/drivers/dma/st_fdma.h b/drivers/dma/st_fdma.h
new file mode 100644
index 0000000..533c811
--- /dev/null
+++ b/drivers/dma/st_fdma.h
@@ -0,0 +1,234 @@
+/*
+ * st_fdma.h
+ *
+ * Copyright (C) 2014 STMicroelectronics
+ * Author: Ludovic Barre <Ludovic.barre@xxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#ifndef __DMA_ST_FDMA_H
+#define __DMA_ST_FDMA_H
+
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/platform_data/dma-st_fdma.h>
+
+#include "virt-dma.h"
+
+#define ST_FDMA_NR_DREQS 32
+#define EM_SLIM	102	/* No official SLIM ELF ID */
+
+enum {
+	CLK_SLIM,
+	CLK_HI,
+	CLK_LOW,
+	CLK_IC,
+	CLK_MAX_NUM,
+};
+
+#define MEM_NAME_SZ 10
+
+struct st_fdma_ram {
+	char name[MEM_NAME_SZ];
+	u32 offset;
+	u32 size;
+};
+
+/**
+ * struct st_fdma_generic_node - Free running/paced generic node
+ *
+ * @length: Length in bytes of a line in a 2D mem to mem
+ * @sstride: Stride, in bytes, between source lines in a 2D data move
+ * @dstride: Stride, in bytes, between destination lines in a 2D data move
+ */
+struct st_fdma_generic_node {
+	u32 length;
+	u32 sstride;
+	u32 dstride;
+};
+
+/**
+ * struct st_fdma_hw_node - Node structure used by fdma hw
+ *
+ * @next: Pointer to next node
+ * @control: Transfer Control Parameters
+ * @nbytes: Number of Bytes to read
+ * @saddr: Source address
+ * @daddr: Destination address
+ *
+ * @generic: generic node for free running/paced transfert type
+ * 2 others transfert type are possible, but not yet implemented
+ *
+ * The NODE structures must be aligned to a 32 byte boundary
+ */
+struct st_fdma_hw_node {
+	u32 next;
+	u32 control;
+	u32 nbytes;
+	u32 saddr;
+	u32 daddr;
+	union {
+		struct st_fdma_generic_node generic;
+	};
+} __aligned(32);
+
+/*
+ * node control parameters
+ */
+#define NODE_CTRL_REQ_MAP_MASK		GENMASK(4, 0)
+#define NODE_CTRL_REQ_MAP_FREE_RUN	0x0
+#define NODE_CTRL_REQ_MAP_DREQ(n)	((n) & NODE_CTRL_REQ_MAP_MASK)
+#define NODE_CTRL_REQ_MAP_EXT		NODE_CTRL_REQ_MAP_MASK
+#define NODE_CTRL_SRC_MASK		GENMASK(6, 5)
+#define NODE_CTRL_SRC_STATIC		BIT(5)
+#define NODE_CTRL_SRC_INCR		BIT(6)
+#define NODE_CTRL_DST_MASK		GENMASK(8, 7)
+#define NODE_CTRL_DST_STATIC		BIT(7)
+#define NODE_CTRL_DST_INCR		BIT(8)
+#define NODE_CTRL_SECURE		BIT(15)
+#define NODE_CTRL_PAUSE_EON		BIT(30)
+#define NODE_CTRL_INT_EON		BIT(31)
+
+/**
+ * struct st_fdma_sw_node - descriptor structure for link list
+ *
+ * @pdesc: Physical address of desc
+ * @node: link used for putting this into a channel queue
+ */
+struct st_fdma_sw_node {
+	dma_addr_t pdesc;
+	struct st_fdma_hw_node *desc;
+};
+
+struct st_fdma_driverdata {
+	const struct st_fdma_ram *fdma_mem;
+	u32 num_mem;
+};
+
+struct st_fdma_desc {
+	struct virt_dma_desc vdesc;
+	struct st_fdma_chan *fchan;
+	bool iscyclic;
+	unsigned int n_nodes;
+	struct st_fdma_sw_node node[];
+};
+
+struct st_fdma_chan {
+	struct st_fdma_dev *fdev;
+	struct dma_pool *node_pool;
+	struct st_fdma_cfg cfg;
+	int dreq_line;
+
+	struct virt_dma_chan vchan;
+	struct st_fdma_desc *fdesc;
+	enum dma_status	status;
+};
+
+struct st_fdma_dev {
+	struct device *dev;
+	const struct st_fdma_driverdata *drvdata;
+	const struct st_fdma_platform_data *pdata;
+	struct dma_device dma_device;
+
+	void __iomem *io_base;
+	struct resource *io_res;
+	struct clk *clks[CLK_MAX_NUM];
+
+	struct st_fdma_chan *chans;
+
+	spinlock_t dreq_lock;
+	unsigned long dreq_mask;
+
+	struct completion fw_ack;
+	atomic_t fw_loaded;
+};
+
+/* Registers*/
+/* FDMA interface */
+#define FDMA_ID_OFST		0x00000
+#define FDMA_VER_OFST		0x00004
+
+#define FDMA_EN_OFST		0x00008
+#define FDMA_EN_RUN			BIT(0)
+
+#define FDMA_CLK_GATE_OFST	0x0000C
+#define FDMA_CLK_GATE_DIS		BIT(0)
+#define FDMA_CLK_GATE_RESET		BIT(2)
+
+#define FDMA_SLIM_PC_OFST	0x00020
+
+#define FDMA_REV_ID_OFST	0x10000
+#define FDMA_REV_ID_MIN_MASK		GENMASK(15, 8)
+#define FDMA_REV_ID_MIN(id)		((id & FDMA_REV_ID_MIN_MASK) >> 8)
+#define FDMA_REV_ID_MAJ_MASK		GENMASK(23, 16)
+#define FDMA_REV_ID_MAJ(id)		((id & FDMA_REV_ID_MAJ_MASK) >> 16)
+
+#define FDMA_STBUS_SYNC_OFST	0x17F88
+#define FDMA_STBUS_SYNC_DIS		BIT(0)
+
+#define FDMA_CMD_STA_OFST	0x17FC0
+#define FDMA_CMD_SET_OFST	0x17FC4
+#define FDMA_CMD_CLR_OFST	0x17FC8
+#define FDMA_CMD_MASK_OFST	0x17FCC
+#define FDMA_CMD_START(ch)		(0x1 << (ch << 1))
+#define FDMA_CMD_PAUSE(ch)		(0x2 << (ch << 1))
+#define FDMA_CMD_FLUSH(ch)		(0x3 << (ch << 1))
+
+#define FDMA_INT_STA_OFST	0x17FD0
+#define FDMA_INT_STA_CH			0x1
+#define FDMA_INT_STA_ERR		0x2
+
+#define FDMA_INT_SET_OFST	0x17FD4
+#define FDMA_INT_CLR_OFST	0x17FD8
+#define FDMA_INT_MASK_OFST	0x17FDC
+
+#define fdma_read(fdev, name) \
+	readl_relaxed((fdev)->io_base + FDMA_##name##_OFST)
+
+#define fdma_write(fdev, val, name) \
+	writel_relaxed((val), (fdev)->io_base + FDMA_##name##_OFST)
+
+/* fchan interface */
+#define FDMA_CH_CMD_OFST	0x10200
+#define FDMA_CH_CMD_STA_MASK		GENMASK(1, 0)
+#define FDMA_CH_CMD_STA_IDLE		(0x0)
+#define FDMA_CH_CMD_STA_START		(0x1)
+#define FDMA_CH_CMD_STA_RUNNING		(0x2)
+#define FDMA_CH_CMD_STA_PAUSED		(0x3)
+#define FDMA_CH_CMD_ERR_MASK		GENMASK(4, 2)
+#define FDMA_CH_CMD_ERR_INT		(0x0 << 2)
+#define FDMA_CH_CMD_ERR_NAND		(0x1 << 2)
+#define FDMA_CH_CMD_ERR_MCHI		(0x2 << 2)
+#define FDMA_CH_CMD_DATA_MASK		GENMASK(31, 5)
+#define fchan_read(fchan, name) \
+	readl_relaxed((fchan)->fdev->io_base \
+			+ (fchan)->vchan.chan.chan_id * 0x4 \
+			+ FDMA_##name##_OFST)
+
+#define fchan_write(fchan, val, name) \
+	writel_relaxed((val), (fchan)->fdev->io_base \
+			+ (fchan)->vchan.chan.chan_id * 0x4 \
+			+ FDMA_##name##_OFST)
+
+/* req interface */
+#define FDMA_REQ_CTRL_OFST	0x10240
+#define dreq_write(fchan, val, name) \
+	writel_relaxed((val), (fchan)->fdev->io_base \
+			+ fchan->dreq_line * 0x04 \
+			+ FDMA_##name##_OFST)
+/* node interface */
+#define FDMA_NODE_SZ 128
+#define FDMA_PTRN_OFST		0x10800
+#define FDMA_CNTN_OFST		0x10808
+#define FDMA_SADDRN_OFST	0x1080c
+#define FDMA_DADDRN_OFST	0x10810
+#define fnode_read(fchan, name) \
+	readl_relaxed((fchan)->fdev->io_base \
+			+ (fchan)->vchan.chan.chan_id * FDMA_NODE_SZ \
+			+ FDMA_##name##_OFST)
+
+#define fnode_write(fchan, val, name) \
+	writel_relaxed((val), (fchan)->fdev->io_base \
+			+ (fchan)->vchan.chan.chan_id * FDMA_NODE_SZ \
+			+ FDMA_##name##_OFST)
+
+#endif	/* __DMA_ST_FDMA_H */
diff --git a/include/linux/platform_data/dma-st_fdma.h b/include/linux/platform_data/dma-st_fdma.h
new file mode 100644
index 0000000..3a1098b
--- /dev/null
+++ b/include/linux/platform_data/dma-st_fdma.h
@@ -0,0 +1,70 @@
+/*
+ * dma-st-fdma.h
+ *
+ * Copyright (C) 2014 STMicroelectronics
+ * Author: Ludovic Barre <Ludovic.barre@xxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#ifndef __PLAT_ST_FDMA_H
+#define __PLAT_ST_FDMA_H
+
+#include <linux/dmaengine.h>
+
+/*
+ * Channel type
+ */
+enum st_fdma_type {
+	ST_FDMA_TYPE_FREE_RUN,
+	ST_FDMA_TYPE_PACED,
+};
+
+struct st_fdma_cfg {
+	struct device_node *of_node;
+	enum st_fdma_type type;
+	dma_addr_t dev_addr;
+	enum dma_transfer_direction dir;
+	int req_line; /* request line */
+	u32 req_ctrl; /* Request control */
+};
+
+/**
+ * struct st_fdma_platform_data - platform specific data for FDMA engine
+ *
+ * @nr_channels:	Number of channels supported by hardware
+ * @fw_name:		The firmware name
+ */
+struct st_fdma_platform_data {
+	u32 nr_channels;
+	const char *fw_name;
+};
+
+/*
+ * request control bits
+ */
+/*replace by genmask >3.13*/
+#define REQ_CTRL_NUM_OPS_MASK		GENMASK(31, 24)
+#define REQ_CTRL_NUM_OPS(n)		(REQ_CTRL_NUM_OPS_MASK & ((n) << 24))
+#define REQ_CTRL_INITIATOR_MASK		BIT(22)
+#define	REQ_CTRL_INIT0			(0x0 << 22)
+#define	REQ_CTRL_INIT1			(0x1 << 22)
+#define REQ_CTRL_INC_ADDR_ON		BIT(21)
+#define REQ_CTRL_DATA_SWAP_ON		BIT(17)
+#define REQ_CTRL_WNR			BIT(14)
+#define REQ_CTRL_OPCODE_MASK		GENMASK(7, 4)
+#define REQ_CTRL_OPCODE_LD_ST1		(0x0 << 4)
+#define REQ_CTRL_OPCODE_LD_ST2		(0x1 << 4)
+#define REQ_CTRL_OPCODE_LD_ST4		(0x2 << 4)
+#define REQ_CTRL_OPCODE_LD_ST8		(0x3 << 4)
+#define REQ_CTRL_OPCODE_LD_ST16		(0x4 << 4)
+#define REQ_CTRL_OPCODE_LD_ST32		(0x5 << 4)
+#define REQ_CTRL_OPCODE_LD_ST64		(0x6 << 4)
+#define REQ_CTRL_HOLDOFF_MASK		GENMASK(2, 0)
+#define REQ_CTRL_HOLDOFF(n)		((n) & REQ_CTRL_HOLDOFF_MASK)
+
+/* bits used by client to configure request control */
+#define REQ_CTRL_CFG_MASK (REQ_CTRL_HOLDOFF_MASK | REQ_CTRL_DATA_SWAP_ON \
+			| REQ_CTRL_INC_ADDR_ON | REQ_CTRL_INITIATOR_MASK)
+
+bool st_fdma_filter_fn(struct dma_chan *chan, void *param);
+
+#endif	/* __PLAT_ST_FDMA_H */
-- 
1.9.1

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