dmaengine: Add STM32 MDMA driver

This patch adds the driver for the STM32 MDMA controller.

Master Direct memory access (MDMA) is used in order to provide high-speed
data transfer between memory and memory or between peripherals and memory.

MDMA controller provides a master AXI interface for main memory and
peripheral registers access (system access port) and a master AHB
interface only for Cortex-M7 TCM memory access (TCM access port).

MDMA works in conjunction with the standard DMA controllers (DMA1 or DMA2).
It offers up to 64 channels, each dedicated to managing memory access
requests from one of the DMA stream memory buffer or other peripherals
(w/ integrated FIFO).

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

3 files changed, 1679 insertions, 0 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 04e381b522b4..73446622ccc9 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -492,6 +492,18 @@ config STM32_DMAMUX
           If you have a board based on such a MCU and wish to use DMAMUX say Y
           here.
 
+config STM32_MDMA
+        bool "STMicroelectronics STM32 master dma support"
+        depends on ARCH_STM32 || COMPILE_TEST
+        select DMA_ENGINE
+        select DMA_OF
+        select DMA_VIRTUAL_CHANNELS
+        help
+          Enable support for the on-chip MDMA controller on STMicroelectronics
+          STM32 platforms.
+          If you have a board based on STM32 SoC and wish to use the master DMA
+          say Y here.
+
 config S3C24XX_DMAC
         bool "Samsung S3C24XX DMA support"
         depends on ARCH_S3C24XX || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index a145ad1426bc..4d2376fdea01 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_STM32_DMA) += stm32-dma.o
 obj-$(CONFIG_STM32_DMAMUX) += stm32-dmamux.o
+obj-$(CONFIG_STM32_MDMA) += stm32-mdma.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
new file mode 100644
index 000000000000..a9cb341c8ee0
--- /dev/null
+++ b/drivers/dma/stm32-mdma.c
@@ -0,0 +1,1666 @@
+/*
+ *
+ * Copyright (C) STMicroelectronics SA 2017
+ * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com>
+ *            Pierre-Yves Mordret <pierre-yves.mordret@st.com>
+ *
+ * License terms: GPL V2.0.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * Driver for STM32 MDMA controller
+ *
+ * Inspired by stm32-dma.c and dma-jz4780.c
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#include "virt-dma.h"
+
+/*  MDMA Generic getter/setter */
+#define STM32_MDMA_SHIFT(n)             (ffs(n) - 1)
+#define STM32_MDMA_SET(n, mask)         (((n) << STM32_MDMA_SHIFT(mask)) & \
+                                         (mask))
+#define STM32_MDMA_GET(n, mask)         (((n) & (mask)) >> \
+                                         STM32_MDMA_SHIFT(mask))
+
+#define STM32_MDMA_GISR0                0x0000 /* MDMA Int Status Reg 1 */
+#define STM32_MDMA_GISR1                0x0004 /* MDMA Int Status Reg 2 */
+
+/* MDMA Channel x interrupt/status register */
+#define STM32_MDMA_CISR(x)              (0x40 + 0x40 * (x)) /* x = 0..62 */
+#define STM32_MDMA_CISR_CRQA            BIT(16)
+#define STM32_MDMA_CISR_TCIF            BIT(4)
+#define STM32_MDMA_CISR_BTIF            BIT(3)
+#define STM32_MDMA_CISR_BRTIF           BIT(2)
+#define STM32_MDMA_CISR_CTCIF           BIT(1)
+#define STM32_MDMA_CISR_TEIF            BIT(0)
+
+/* MDMA Channel x interrupt flag clear register */
+#define STM32_MDMA_CIFCR(x)             (0x44 + 0x40 * (x))
+#define STM32_MDMA_CIFCR_CLTCIF         BIT(4)
+#define STM32_MDMA_CIFCR_CBTIF          BIT(3)
+#define STM32_MDMA_CIFCR_CBRTIF         BIT(2)
+#define STM32_MDMA_CIFCR_CCTCIF         BIT(1)
+#define STM32_MDMA_CIFCR_CTEIF          BIT(0)
+#define STM32_MDMA_CIFCR_CLEAR_ALL      (STM32_MDMA_CIFCR_CLTCIF \
+                                        | STM32_MDMA_CIFCR_CBTIF \
+                                        | STM32_MDMA_CIFCR_CBRTIF \
+                                        | STM32_MDMA_CIFCR_CCTCIF \
+                                        | STM32_MDMA_CIFCR_CTEIF)
+
+/* MDMA Channel x error status register */
+#define STM32_MDMA_CESR(x)              (0x48 + 0x40 * (x))
+#define STM32_MDMA_CESR_BSE             BIT(11)
+#define STM32_MDMA_CESR_ASR             BIT(10)
+#define STM32_MDMA_CESR_TEMD            BIT(9)
+#define STM32_MDMA_CESR_TELD            BIT(8)
+#define STM32_MDMA_CESR_TED             BIT(7)
+#define STM32_MDMA_CESR_TEA_MASK        GENMASK(6, 0)
+
+/* MDMA Channel x control register */
+#define STM32_MDMA_CCR(x)               (0x4C + 0x40 * (x))
+#define STM32_MDMA_CCR_SWRQ             BIT(16)
+#define STM32_MDMA_CCR_WEX              BIT(14)
+#define STM32_MDMA_CCR_HEX              BIT(13)
+#define STM32_MDMA_CCR_BEX              BIT(12)
+#define STM32_MDMA_CCR_PL_MASK          GENMASK(7, 6)
+#define STM32_MDMA_CCR_PL(n)            STM32_MDMA_SET(n, \
+                                                       STM32_MDMA_CCR_PL_MASK)
+#define STM32_MDMA_CCR_TCIE             BIT(5)
+#define STM32_MDMA_CCR_BTIE             BIT(4)
+#define STM32_MDMA_CCR_BRTIE            BIT(3)
+#define STM32_MDMA_CCR_CTCIE            BIT(2)
+#define STM32_MDMA_CCR_TEIE             BIT(1)
+#define STM32_MDMA_CCR_EN               BIT(0)
+#define STM32_MDMA_CCR_IRQ_MASK         (STM32_MDMA_CCR_TCIE \
+                                        | STM32_MDMA_CCR_BTIE \
+                                        | STM32_MDMA_CCR_BRTIE \
+                                        | STM32_MDMA_CCR_CTCIE \
+                                        | STM32_MDMA_CCR_TEIE)
+
+/* MDMA Channel x transfer configuration register */
+#define STM32_MDMA_CTCR(x)              (0x50 + 0x40 * (x))
+#define STM32_MDMA_CTCR_BWM             BIT(31)
+#define STM32_MDMA_CTCR_SWRM            BIT(30)
+#define STM32_MDMA_CTCR_TRGM_MSK        GENMASK(29, 28)
+#define STM32_MDMA_CTCR_TRGM(n)         STM32_MDMA_SET((n), \
+                                                       STM32_MDMA_CTCR_TRGM_MSK)
+#define STM32_MDMA_CTCR_TRGM_GET(n)     STM32_MDMA_GET((n), \
+                                                       STM32_MDMA_CTCR_TRGM_MSK)
+#define STM32_MDMA_CTCR_PAM_MASK        GENMASK(27, 26)
+#define STM32_MDMA_CTCR_PAM(n)          STM32_MDMA_SET(n, \
+                                                       STM32_MDMA_CTCR_PAM_MASK)
+#define STM32_MDMA_CTCR_PKE             BIT(25)
+#define STM32_MDMA_CTCR_TLEN_MSK        GENMASK(24, 18)
+#define STM32_MDMA_CTCR_TLEN(n)         STM32_MDMA_SET((n), \
+                                                       STM32_MDMA_CTCR_TLEN_MSK)
+#define STM32_MDMA_CTCR_TLEN_GET(n)     STM32_MDMA_GET((n), \
+                                                       STM32_MDMA_CTCR_TLEN_MSK)
+#define STM32_MDMA_CTCR_LEN2_MSK        GENMASK(25, 18)
+#define STM32_MDMA_CTCR_LEN2(n)         STM32_MDMA_SET((n), \
+                                                       STM32_MDMA_CTCR_LEN2_MSK)
+#define STM32_MDMA_CTCR_LEN2_GET(n)     STM32_MDMA_GET((n), \
+                                                       STM32_MDMA_CTCR_LEN2_MSK)
+#define STM32_MDMA_CTCR_DBURST_MASK     GENMASK(17, 15)
+#define STM32_MDMA_CTCR_DBURST(n)       STM32_MDMA_SET(n, \
+                                                    STM32_MDMA_CTCR_DBURST_MASK)
+#define STM32_MDMA_CTCR_SBURST_MASK     GENMASK(14, 12)
+#define STM32_MDMA_CTCR_SBURST(n)       STM32_MDMA_SET(n, \
+                                                    STM32_MDMA_CTCR_SBURST_MASK)
+#define STM32_MDMA_CTCR_DINCOS_MASK     GENMASK(11, 10)
+#define STM32_MDMA_CTCR_DINCOS(n)       STM32_MDMA_SET((n), \
+                                                    STM32_MDMA_CTCR_DINCOS_MASK)
+#define STM32_MDMA_CTCR_SINCOS_MASK     GENMASK(9, 8)
+#define STM32_MDMA_CTCR_SINCOS(n)       STM32_MDMA_SET((n), \
+                                                    STM32_MDMA_CTCR_SINCOS_MASK)
+#define STM32_MDMA_CTCR_DSIZE_MASK      GENMASK(7, 6)
+#define STM32_MDMA_CTCR_DSIZE(n)        STM32_MDMA_SET(n, \
+                                                     STM32_MDMA_CTCR_DSIZE_MASK)
+#define STM32_MDMA_CTCR_SSIZE_MASK      GENMASK(5, 4)
+#define STM32_MDMA_CTCR_SSIZE(n)        STM32_MDMA_SET(n, \
+                                                     STM32_MDMA_CTCR_SSIZE_MASK)
+#define STM32_MDMA_CTCR_DINC_MASK       GENMASK(3, 2)
+#define STM32_MDMA_CTCR_DINC(n)         STM32_MDMA_SET((n), \
+                                                      STM32_MDMA_CTCR_DINC_MASK)
+#define STM32_MDMA_CTCR_SINC_MASK       GENMASK(1, 0)
+#define STM32_MDMA_CTCR_SINC(n)         STM32_MDMA_SET((n), \
+                                                      STM32_MDMA_CTCR_SINC_MASK)
+#define STM32_MDMA_CTCR_CFG_MASK        (STM32_MDMA_CTCR_SINC_MASK \
+                                        | STM32_MDMA_CTCR_DINC_MASK \
+                                        | STM32_MDMA_CTCR_SINCOS_MASK \
+                                        | STM32_MDMA_CTCR_DINCOS_MASK \
+                                        | STM32_MDMA_CTCR_LEN2_MSK \
+                                        | STM32_MDMA_CTCR_TRGM_MSK)
+
+/* MDMA Channel x block number of data register */
+#define STM32_MDMA_CBNDTR(x)            (0x54 + 0x40 * (x))
+#define STM32_MDMA_CBNDTR_BRC_MK        GENMASK(31, 20)
+#define STM32_MDMA_CBNDTR_BRC(n)        STM32_MDMA_SET(n, \
+                                                       STM32_MDMA_CBNDTR_BRC_MK)
+#define STM32_MDMA_CBNDTR_BRC_GET(n)    STM32_MDMA_GET((n), \
+                                                       STM32_MDMA_CBNDTR_BRC_MK)
+
+#define STM32_MDMA_CBNDTR_BRDUM         BIT(19)
+#define STM32_MDMA_CBNDTR_BRSUM         BIT(18)
+#define STM32_MDMA_CBNDTR_BNDT_MASK     GENMASK(16, 0)
+#define STM32_MDMA_CBNDTR_BNDT(n)       STM32_MDMA_SET(n, \
+                                                    STM32_MDMA_CBNDTR_BNDT_MASK)
+
+/* MDMA Channel x source address register */
+#define STM32_MDMA_CSAR(x)              (0x58 + 0x40 * (x))
+
+/* MDMA Channel x destination address register */
+#define STM32_MDMA_CDAR(x)              (0x5C + 0x40 * (x))
+
+/* MDMA Channel x block repeat address update register */
+#define STM32_MDMA_CBRUR(x)             (0x60 + 0x40 * (x))
+#define STM32_MDMA_CBRUR_DUV_MASK       GENMASK(31, 16)
+#define STM32_MDMA_CBRUR_DUV(n)         STM32_MDMA_SET(n, \
+                                                      STM32_MDMA_CBRUR_DUV_MASK)
+#define STM32_MDMA_CBRUR_SUV_MASK       GENMASK(15, 0)
+#define STM32_MDMA_CBRUR_SUV(n)         STM32_MDMA_SET(n, \
+                                                      STM32_MDMA_CBRUR_SUV_MASK)
+
+/* MDMA Channel x link address register */
+#define STM32_MDMA_CLAR(x)              (0x64 + 0x40 * (x))
+
+/* MDMA Channel x trigger and bus selection register */
+#define STM32_MDMA_CTBR(x)              (0x68 + 0x40 * (x))
+#define STM32_MDMA_CTBR_DBUS            BIT(17)
+#define STM32_MDMA_CTBR_SBUS            BIT(16)
+#define STM32_MDMA_CTBR_TSEL_MASK       GENMASK(7, 0)
+#define STM32_MDMA_CTBR_TSEL(n)         STM32_MDMA_SET(n, \
+                                                      STM32_MDMA_CTBR_TSEL_MASK)
+
+/* MDMA Channel x mask address register */
+#define STM32_MDMA_CMAR(x)              (0x70 + 0x40 * (x))
+
+/* MDMA Channel x mask data register */
+#define STM32_MDMA_CMDR(x)              (0x74 + 0x40 * (x))
+
+#define STM32_MDMA_MAX_BUF_LEN          128
+#define STM32_MDMA_MAX_BLOCK_LEN        65536
+#define STM32_MDMA_MAX_CHANNELS         63
+#define STM32_MDMA_MAX_REQUESTS         256
+#define STM32_MDMA_MAX_BURST            128
+#define STM32_MDMA_VERY_HIGH_PRIORITY   0x11
+
+enum stm32_mdma_trigger_mode {
+        STM32_MDMA_BUFFER,
+        STM32_MDMA_BLOCK,
+        STM32_MDMA_BLOCK_REP,
+        STM32_MDMA_LINKED_LIST,
+};
+
+enum stm32_mdma_width {
+        STM32_MDMA_BYTE,
+        STM32_MDMA_HALF_WORD,
+        STM32_MDMA_WORD,
+        STM32_MDMA_DOUBLE_WORD,
+};
+
+enum stm32_mdma_inc_mode {
+        STM32_MDMA_FIXED = 0,
+        STM32_MDMA_INC = 2,
+        STM32_MDMA_DEC = 3,
+};
+
+struct stm32_mdma_chan_config {
+        u32 request;
+        u32 priority_level;
+        u32 transfer_config;
+        u32 mask_addr;
+        u32 mask_data;
+};
+
+struct stm32_mdma_hwdesc {
+        u32 ctcr;
+        u32 cbndtr;
+        u32 csar;
+        u32 cdar;
+        u32 cbrur;
+        u32 clar;
+        u32 ctbr;
+        u32 dummy;
+        u32 cmar;
+        u32 cmdr;
+} __aligned(64);
+
+struct stm32_mdma_desc {
+        struct virt_dma_desc vdesc;
+        u32 ccr;
+        struct stm32_mdma_hwdesc *hwdesc;
+        dma_addr_t hwdesc_phys;
+        bool cyclic;
+        u32 count;
+};
+
+struct stm32_mdma_chan {
+        struct virt_dma_chan vchan;
+        struct dma_pool *desc_pool;
+        u32 id;
+        struct stm32_mdma_desc *desc;
+        u32 curr_hwdesc;
+        struct dma_slave_config dma_config;
+        struct stm32_mdma_chan_config chan_config;
+        bool busy;
+        u32 mem_burst;
+        u32 mem_width;
+};
+
+struct stm32_mdma_device {
+        struct dma_device ddev;
+        void __iomem *base;
+        struct clk *clk;
+        int irq;
+        struct reset_control *rst;
+        u32 nr_channels;
+        u32 nr_requests;
+        u32 nr_ahb_addr_masks;
+        struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
+        u32 ahb_addr_masks[];
+};
+
+static struct stm32_mdma_device *stm32_mdma_get_dev(
+        struct stm32_mdma_chan *chan)
+{
+        return container_of(chan->vchan.chan.device, struct stm32_mdma_device,
+                            ddev);
+}
+
+static struct stm32_mdma_chan *to_stm32_mdma_chan(struct dma_chan *c)
+{
+        return container_of(c, struct stm32_mdma_chan, vchan.chan);
+}
+
+static struct stm32_mdma_desc *to_stm32_mdma_desc(struct virt_dma_desc *vdesc)
+{
+        return container_of(vdesc, struct stm32_mdma_desc, vdesc);
+}
+
+static struct device *chan2dev(struct stm32_mdma_chan *chan)
+{
+        return &chan->vchan.chan.dev->device;
+}
+
+static struct device *mdma2dev(struct stm32_mdma_device *mdma_dev)
+{
+        return mdma_dev->ddev.dev;
+}
+
+static u32 stm32_mdma_read(struct stm32_mdma_device *dmadev, u32 reg)
+{
+        return readl_relaxed(dmadev->base + reg);
+}
+
+static void stm32_mdma_write(struct stm32_mdma_device *dmadev, u32 reg, u32 val)
+{
+        writel_relaxed(val, dmadev->base + reg);
+}
+
+static void stm32_mdma_set_bits(struct stm32_mdma_device *dmadev, u32 reg,
+                                u32 mask)
+{
+        void __iomem *addr = dmadev->base + reg;
+
+        writel_relaxed(readl_relaxed(addr) | mask, addr);
+}
+
+static void stm32_mdma_clr_bits(struct stm32_mdma_device *dmadev, u32 reg,
+                                u32 mask)
+{
+        void __iomem *addr = dmadev->base + reg;
+
+        writel_relaxed(readl_relaxed(addr) & ~mask, addr);
+}
+
+static struct stm32_mdma_desc *stm32_mdma_alloc_desc(
+                struct stm32_mdma_chan *chan, u32 count)
+{
+        struct stm32_mdma_desc *desc;
+
+        desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+        if (!desc)
+                return NULL;
+
+        desc->hwdesc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
+                                      &desc->hwdesc_phys);
+        if (!desc->hwdesc) {
+                dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
+                kfree(desc);
+                return NULL;
+        }
+
+        desc->count = count;
+
+        return desc;
+}
+
+static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
+{
+        struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
+
+        dma_pool_free(chan->desc_pool, desc->hwdesc, desc->hwdesc_phys);
+        kfree(desc);
+}
+
+static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
+                                enum dma_slave_buswidth width)
+{
+        switch (width) {
+        case DMA_SLAVE_BUSWIDTH_1_BYTE:
+        case DMA_SLAVE_BUSWIDTH_2_BYTES:
+        case DMA_SLAVE_BUSWIDTH_4_BYTES:
+        case DMA_SLAVE_BUSWIDTH_8_BYTES:
+                return ffs(width) - 1;
+        default:
+                dev_err(chan2dev(chan), "Dma bus width %i not supported\n",
+                        width);
+                return -EINVAL;
+        }
+}
+
+static enum dma_slave_buswidth stm32_mdma_get_max_width(u32 buf_len, u32 tlen)
+{
+        enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
+
+        for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
+             max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
+             max_width >>= 1) {
+                if (((buf_len % max_width) == 0) && (tlen >= max_width))
+                        break;
+        }
+
+        return max_width;
+}
+
+static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
+                                     enum dma_slave_buswidth width)
+{
+        u32 best_burst = max_burst;
+        u32 burst_len = best_burst * width;
+
+        while ((burst_len > 0) && (tlen % burst_len)) {
+                best_burst = best_burst >> 1;
+                burst_len = best_burst * width;
+        }
+
+        return (best_burst > 0) ? best_burst : 1;
+}
+
+static int stm32_mdma_disable_chan(struct stm32_mdma_chan *chan)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        u32 ccr, cisr, id, reg;
+        int ret;
+
+        id = chan->id;
+        reg = STM32_MDMA_CCR(id);
+
+        /* Disable interrupts */
+        stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_IRQ_MASK);
+
+        ccr = stm32_mdma_read(dmadev, reg);
+        if (ccr & STM32_MDMA_CCR_EN) {
+                stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_EN);
+
+                /* Ensure that any ongoing transfer has been completed */
+                ret = readl_relaxed_poll_timeout_atomic(
+                                dmadev->base + STM32_MDMA_CISR(id), cisr,
+                                (cisr & STM32_MDMA_CISR_CTCIF), 10, 1000);
+                if (ret) {
+                        dev_err(chan2dev(chan), "%s: timeout!\n", __func__);
+                        return -EBUSY;
+                }
+        }
+
+        return 0;
+}
+
+static void stm32_mdma_stop(struct stm32_mdma_chan *chan)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        u32 status;
+        int ret;
+
+        /* Disable DMA */
+        ret = stm32_mdma_disable_chan(chan);
+        if (ret < 0)
+                return;
+
+        /* Clear interrupt status if it is there */
+        status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
+        if (status) {
+                dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
+                        __func__, status);
+                stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
+        }
+
+        chan->busy = false;
+}
+
+static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
+                               u32 ctbr_mask, u32 src_addr)
+{
+        u32 mask;
+        int i;
+
+        /* Check if memory device is on AHB or AXI */
+        *ctbr &= ~ctbr_mask;
+        mask = src_addr & 0xF0000000;
+        for (i = 0; i < dmadev->nr_ahb_addr_masks; i++) {
+                if (mask == dmadev->ahb_addr_masks[i]) {
+                        *ctbr |= ctbr_mask;
+                        break;
+                }
+        }
+}
+
+static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
+                                     enum dma_transfer_direction direction,
+                                     u32 *mdma_ccr, u32 *mdma_ctcr,
+                                     u32 *mdma_ctbr, u32 buf_len)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
+        enum dma_slave_buswidth src_addr_width, dst_addr_width;
+        phys_addr_t src_addr, dst_addr;
+        int src_bus_width, dst_bus_width;
+        u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
+        u32 ccr, ctcr, ctbr, tlen;
+
+        src_addr_width = chan->dma_config.src_addr_width;
+        dst_addr_width = chan->dma_config.dst_addr_width;
+        src_maxburst = chan->dma_config.src_maxburst;
+        dst_maxburst = chan->dma_config.dst_maxburst;
+
+        ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
+        ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
+        ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
+
+        /* Enable HW request mode */
+        ctcr &= ~STM32_MDMA_CTCR_SWRM;
+
+        /* Set DINC, SINC, DINCOS, SINCOS, TRGM and TLEN retrieve from DT */
+        ctcr &= ~STM32_MDMA_CTCR_CFG_MASK;
+        ctcr |= chan_config->transfer_config & STM32_MDMA_CTCR_CFG_MASK;
+
+        /*
+         * For buffer transfer length (TLEN) we have to set
+         * the number of bytes - 1 in CTCR register
+         */
+        tlen = STM32_MDMA_CTCR_LEN2_GET(ctcr);
+        ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
+        ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
+
+        /* Check burst size constraints */
+        if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
+            dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
+                dev_err(chan2dev(chan),
+                        "burst size * bus width higher than %d bytes\n",
+                        STM32_MDMA_MAX_BURST);
+                return -EINVAL;
+        }
+
+        if ((!is_power_of_2(src_maxburst) && src_maxburst > 0) ||
+            (!is_power_of_2(dst_maxburst) && dst_maxburst > 0)) {
+                dev_err(chan2dev(chan), "burst size must be a power of 2\n");
+                return -EINVAL;
+        }
+
+        /*
+         * Configure channel control:
+         * - Clear SW request as in this case this is a HW one
+         * - Clear WEX, HEX and BEX bits
+         * - Set priority level
+         */
+        ccr &= ~(STM32_MDMA_CCR_SWRQ | STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
+                 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK);
+        ccr |= STM32_MDMA_CCR_PL(chan_config->priority_level);
+
+        /* Configure Trigger selection */
+        ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
+        ctbr |= STM32_MDMA_CTBR_TSEL(chan_config->request);
+
+        switch (direction) {
+        case DMA_MEM_TO_DEV:
+                /* Set device data size */
+                dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
+                if (dst_bus_width < 0)
+                        return dst_bus_width;
+                ctcr &= ~STM32_MDMA_CTCR_DSIZE_MASK;
+                ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width);
+
+                /* Set device burst value */
+                dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
+                                                           dst_maxburst,
+                                                           dst_addr_width);
+                chan->mem_burst = dst_best_burst;
+                ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
+                ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
+
+                /* Set memory data size */
+                src_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
+                chan->mem_width = src_addr_width;
+                src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
+                if (src_bus_width < 0)
+                        return src_bus_width;
+                ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK |
+                        STM32_MDMA_CTCR_SINCOS_MASK;
+                ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width) |
+                        STM32_MDMA_CTCR_SINCOS(src_bus_width);
+
+                /* Set memory burst value */
+                src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
+                src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
+                                                           src_maxburst,
+                                                           src_addr_width);
+                chan->mem_burst = src_best_burst;
+                ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
+                ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
+
+                /* Select bus */
+                dst_addr = chan->dma_config.dst_addr;
+                stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
+                                   dst_addr);
+
+                /* Set destination address */
+                stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
+                break;
+
+        case DMA_DEV_TO_MEM:
+                /* Set device data size */
+                src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
+                if (src_bus_width < 0)
+                        return src_bus_width;
+                ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK;
+                ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width);
+
+                /* Set device burst value */
+                src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
+                                                           src_maxburst,
+                                                           src_addr_width);
+                ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
+                ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
+
+                /* Set memory data size */
+                dst_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
+                chan->mem_width = dst_addr_width;
+                dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
+                if (dst_bus_width < 0)
+                        return dst_bus_width;
+                ctcr &= ~(STM32_MDMA_CTCR_DSIZE_MASK |
+                        STM32_MDMA_CTCR_DINCOS_MASK);
+                ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
+                        STM32_MDMA_CTCR_DINCOS(dst_bus_width);
+
+                /* Set memory burst value */
+                dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
+                dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
+                                                           dst_maxburst,
+                                                           dst_addr_width);
+                ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
+                ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
+
+                /* Select bus */
+                src_addr = chan->dma_config.src_addr;
+                stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
+                                   src_addr);
+
+                /* Set source address */
+                stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
+                break;
+
+        default:
+                dev_err(chan2dev(chan), "Dma direction is not supported\n");
+                return -EINVAL;
+        }
+
+        *mdma_ccr = ccr;
+        *mdma_ctcr = ctcr;
+        *mdma_ctbr = ctbr;
+
+        return 0;
+}
+
+static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
+                                   struct stm32_mdma_hwdesc *hwdesc)
+{
+        dev_dbg(chan2dev(chan), "hwdesc:  0x%08x\n", (unsigned int)hwdesc);
+        dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n", hwdesc->ctcr);
+        dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n", hwdesc->cbndtr);
+        dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n", hwdesc->csar);
+        dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n", hwdesc->cdar);
+        dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n", hwdesc->cbrur);
+        dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n", hwdesc->clar);
+        dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n", hwdesc->ctbr);
+        dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n", hwdesc->cmar);
+        dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n\n", hwdesc->cmdr);
+}
+
+static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
+                                    struct stm32_mdma_desc *desc,
+                                    enum dma_transfer_direction dir, u32 count,
+                                    dma_addr_t src_addr, dma_addr_t dst_addr,
+                                    u32 len, u32 ctcr, u32 ctbr, bool is_last,
+                                    bool is_first, bool is_cyclic)
+{
+        struct stm32_mdma_chan_config *config = &chan->chan_config;
+        struct stm32_mdma_hwdesc *hwdesc;
+        u32 next = count + 1;
+
+        hwdesc = &desc->hwdesc[count];
+        hwdesc->ctcr = ctcr;
+        hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
+                        STM32_MDMA_CBNDTR_BRDUM |
+                        STM32_MDMA_CBNDTR_BRSUM |
+                        STM32_MDMA_CBNDTR_BNDT_MASK);
+        hwdesc->cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
+        hwdesc->csar = src_addr;
+        hwdesc->cdar = dst_addr;
+        hwdesc->cbrur = 0;
+        hwdesc->clar = desc->hwdesc_phys + next * sizeof(*hwdesc);
+        hwdesc->ctbr = ctbr;
+        hwdesc->cmar = config->mask_addr;
+        hwdesc->cmdr = config->mask_data;
+
+        if (is_last) {
+                if (is_cyclic)
+                        hwdesc->clar = desc->hwdesc_phys;
+                else
+                        hwdesc->clar = 0;
+        }
+
+        stm32_mdma_dump_hwdesc(chan, hwdesc);
+}
+
+static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
+                                 struct stm32_mdma_desc *desc,
+                                 struct scatterlist *sgl, u32 sg_len,
+                                 enum dma_transfer_direction direction)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct dma_slave_config *dma_config = &chan->dma_config;
+        struct scatterlist *sg;
+        dma_addr_t src_addr, dst_addr;
+        u32 ccr, ctcr, ctbr;
+        int i, ret = 0;
+
+        for_each_sg(sgl, sg, sg_len, i) {
+                if (sg_dma_len(sg) > STM32_MDMA_MAX_BLOCK_LEN) {
+                        dev_err(chan2dev(chan), "Invalid block len\n");
+                        return -EINVAL;
+                }
+
+                ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
+                                                &ctbr, sg_dma_len(sg));
+                if (ret < 0)
+                        return ret;
+
+                if (direction == DMA_MEM_TO_DEV) {
+                        src_addr = sg_dma_address(sg);
+                        dst_addr = dma_config->dst_addr;
+                        stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
+                                           src_addr);
+                } else {
+                        src_addr = dma_config->src_addr;
+                        dst_addr = sg_dma_address(sg);
+                        stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
+                                           dst_addr);
+                }
+
+                stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
+                                        dst_addr, sg_dma_len(sg), ctcr, ctbr,
+                                        i == sg_len - 1, i == 0, false);
+        }
+
+        /* Enable interrupts */
+        ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
+        ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE;
+        if (sg_len > 1)
+                ccr |= STM32_MDMA_CCR_BTIE;
+        desc->ccr = ccr;
+
+        return 0;
+}
+
+static struct dma_async_tx_descriptor *
+stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
+                         u32 sg_len, enum dma_transfer_direction direction,
+                         unsigned long flags, void *context)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_desc *desc;
+        int ret;
+
+        /*
+         * Once DMA is in setup cyclic mode the channel we cannot assign this
+         * channel anymore. The DMA channel needs to be aborted or terminated
+         * for allowing another request.
+         */
+        if (chan->desc && chan->desc->cyclic) {
+                dev_err(chan2dev(chan),
+                        "Request not allowed when dma in cyclic mode\n");
+                return NULL;
+        }
+
+        desc = stm32_mdma_alloc_desc(chan, sg_len);
+        if (!desc)
+                return NULL;
+
+        ret = stm32_mdma_setup_xfer(chan, desc, sgl, sg_len, direction);
+        if (ret < 0)
+                goto xfer_setup_err;
+
+        desc->cyclic = false;
+
+        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+
+xfer_setup_err:
+        dma_pool_free(chan->desc_pool, &desc->hwdesc, desc->hwdesc_phys);
+        kfree(desc);
+        return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
+                           size_t buf_len, size_t period_len,
+                           enum dma_transfer_direction direction,
+                           unsigned long flags)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct dma_slave_config *dma_config = &chan->dma_config;
+        struct stm32_mdma_desc *desc;
+        dma_addr_t src_addr, dst_addr;
+        u32 ccr, ctcr, ctbr, count;
+        int i, ret;
+
+        /*
+         * Once DMA is in setup cyclic mode the channel we cannot assign this
+         * channel anymore. The DMA channel needs to be aborted or terminated
+         * for allowing another request.
+         */
+        if (chan->desc && chan->desc->cyclic) {
+                dev_err(chan2dev(chan),
+                        "Request not allowed when dma in cyclic mode\n");
+                return NULL;
+        }
+
+        if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
+                dev_err(chan2dev(chan), "Invalid buffer/period len\n");
+                return NULL;
+        }
+
+        if (buf_len % period_len) {
+                dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
+                return NULL;
+        }
+
+        count = buf_len / period_len;
+
+        desc = stm32_mdma_alloc_desc(chan, count);
+        if (!desc)
+                return NULL;
+
+        ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr, &ctbr,
+                                        period_len);
+        if (ret < 0)
+                goto xfer_setup_err;
+
+        /* Enable interrupts */
+        ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
+        ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
+        desc->ccr = ccr;
+
+        /* Select bus */
+        if (direction == DMA_MEM_TO_DEV) {
+                src_addr = buf_addr;
+                stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
+                                   src_addr);
+        } else {
+                dst_addr = buf_addr;
+                stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
+                                   dst_addr);
+        }
+
+        /* Configure hwdesc list */
+        for (i = 0; i < count; i++) {
+                if (direction == DMA_MEM_TO_DEV) {
+                        src_addr = buf_addr + i * period_len;
+                        dst_addr = dma_config->dst_addr;
+                } else {
+                        src_addr = dma_config->src_addr;
+                        dst_addr = buf_addr + i * period_len;
+                }
+
+                stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
+                                        dst_addr, period_len, ctcr, ctbr,
+                                        i == count - 1, i == 0, true);
+        }
+
+        desc->cyclic = true;
+
+        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+
+xfer_setup_err:
+        dma_pool_free(chan->desc_pool, &desc->hwdesc, desc->hwdesc_phys);
+        kfree(desc);
+        return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
+                           size_t len, unsigned long flags)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        enum dma_slave_buswidth max_width;
+        struct stm32_mdma_desc *desc;
+        struct stm32_mdma_hwdesc *hwdesc;
+        u32 ccr, ctcr, ctbr, cbndtr, count, max_burst, mdma_burst;
+        u32 best_burst, tlen;
+        size_t xfer_count, offset;
+        int src_bus_width, dst_bus_width;
+        int i;
+
+        /*
+         * Once DMA is in setup cyclic mode the channel we cannot assign this
+         * channel anymore. The DMA channel needs to be aborted or terminated
+         * to allow another request
+         */
+        if (chan->desc && chan->desc->cyclic) {
+                dev_err(chan2dev(chan),
+                        "Request not allowed when dma in cyclic mode\n");
+                return NULL;
+        }
+
+        count = DIV_ROUND_UP(len, STM32_MDMA_MAX_BLOCK_LEN);
+        desc = stm32_mdma_alloc_desc(chan, count);
+        if (!desc)
+                return NULL;
+
+        ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
+        ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
+        ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
+        cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
+
+        /* Enable sw req, some interrupts and clear other bits */
+        ccr &= ~(STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
+                 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK |
+                 STM32_MDMA_CCR_IRQ_MASK);
+        ccr |= STM32_MDMA_CCR_TEIE;
+
+        /* Enable SW request mode, dest/src inc and clear other bits */
+        ctcr &= ~(STM32_MDMA_CTCR_BWM | STM32_MDMA_CTCR_TRGM_MSK |
+                  STM32_MDMA_CTCR_PAM_MASK | STM32_MDMA_CTCR_PKE |
+                  STM32_MDMA_CTCR_TLEN_MSK | STM32_MDMA_CTCR_DBURST_MASK |
+                  STM32_MDMA_CTCR_SBURST_MASK | STM32_MDMA_CTCR_DINCOS_MASK |
+                  STM32_MDMA_CTCR_SINCOS_MASK | STM32_MDMA_CTCR_DSIZE_MASK |
+                  STM32_MDMA_CTCR_SSIZE_MASK | STM32_MDMA_CTCR_DINC_MASK |
+                  STM32_MDMA_CTCR_SINC_MASK);
+        ctcr |= STM32_MDMA_CTCR_SWRM | STM32_MDMA_CTCR_SINC(STM32_MDMA_INC) |
+                STM32_MDMA_CTCR_DINC(STM32_MDMA_INC);
+
+        /* Reset HW request */
+        ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
+
+        /* Select bus */
+        stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS, src);
+        stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS, dest);
+
+        /* Clear CBNDTR registers */
+        cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK | STM32_MDMA_CBNDTR_BRDUM |
+                        STM32_MDMA_CBNDTR_BRSUM | STM32_MDMA_CBNDTR_BNDT_MASK);
+
+        if (len <= STM32_MDMA_MAX_BLOCK_LEN) {
+                cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
+                if (len <= STM32_MDMA_MAX_BUF_LEN) {
+                        /* Setup a buffer transfer */
+                        ccr |= STM32_MDMA_CCR_TCIE | STM32_MDMA_CCR_CTCIE;
+                        ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BUFFER);
+                } else {
+                        /* Setup a block transfer */
+                        ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
+                        ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BLOCK);
+                }
+
+                tlen = STM32_MDMA_MAX_BUF_LEN;
+                ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
+
+                /* Set source best burst size */
+                max_width = stm32_mdma_get_max_width(len, tlen);
+                if (src % max_width)
+                        max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+                src_bus_width = stm32_mdma_get_width(chan, max_width);
+
+                max_burst = tlen / max_width;
+                best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
+                                                       max_width);
+                mdma_burst = ilog2(best_burst);
+
+                ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
+                        STM32_MDMA_CTCR_SSIZE(src_bus_width) |
+                        STM32_MDMA_CTCR_SINCOS(src_bus_width);
+
+                /* Set destination best burst size */
+                max_width = stm32_mdma_get_max_width(len, tlen);
+                if (dest % max_width)
+                        max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+                dst_bus_width = stm32_mdma_get_width(chan, max_width);
+
+                max_burst = tlen / max_width;
+                best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
+                                                       max_width);
+                mdma_burst = ilog2(best_burst);
+
+                ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
+                        STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
+                        STM32_MDMA_CTCR_DINCOS(dst_bus_width);
+
+                if (dst_bus_width != src_bus_width)
+                        ctcr |= STM32_MDMA_CTCR_PKE;
+
+                /* Prepare hardware descriptor */
+                hwdesc = desc->hwdesc;
+                hwdesc->ctcr = ctcr;
+                hwdesc->cbndtr = cbndtr;
+                hwdesc->csar = src;
+                hwdesc->cdar = dest;
+                hwdesc->cbrur = 0;
+                hwdesc->clar = 0;
+                hwdesc->ctbr = ctbr;
+                hwdesc->cmar = 0;
+                hwdesc->cmdr = 0;
+
+                stm32_mdma_dump_hwdesc(chan, hwdesc);
+        } else {
+                /* Setup a LLI transfer */
+                ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
+                        STM32_MDMA_CTCR_TLEN((STM32_MDMA_MAX_BUF_LEN - 1));
+                ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
+                tlen = STM32_MDMA_MAX_BUF_LEN;
+
+                for (i = 0, offset = 0; offset < len;
+                     i++, offset += xfer_count) {
+                        xfer_count = min_t(size_t, len - offset,
+                                           STM32_MDMA_MAX_BLOCK_LEN);
+
+                        /* Set source best burst size */
+                        max_width = stm32_mdma_get_max_width(len, tlen);
+                        if (src % max_width)
+                                max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+                        src_bus_width = stm32_mdma_get_width(chan, max_width);
+
+                        max_burst = tlen / max_width;
+                        best_burst = stm32_mdma_get_best_burst(len, tlen,
+                                                               max_burst,
+                                                               max_width);
+                        mdma_burst = ilog2(best_burst);
+
+                        ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
+                                STM32_MDMA_CTCR_SSIZE(src_bus_width) |
+                                STM32_MDMA_CTCR_SINCOS(src_bus_width);
+
+                        /* Set destination best burst size */
+                        max_width = stm32_mdma_get_max_width(len, tlen);
+                        if (dest % max_width)
+                                max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+                        dst_bus_width = stm32_mdma_get_width(chan, max_width);
+
+                        max_burst = tlen / max_width;
+                        best_burst = stm32_mdma_get_best_burst(len, tlen,
+                                                               max_burst,
+                                                               max_width);
+                        mdma_burst = ilog2(best_burst);
+
+                        ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
+                                STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
+                                STM32_MDMA_CTCR_DINCOS(dst_bus_width);
+
+                        if (dst_bus_width != src_bus_width)
+                                ctcr |= STM32_MDMA_CTCR_PKE;
+
+                        /* Prepare hardware descriptor */
+                        stm32_mdma_setup_hwdesc(chan, desc, DMA_MEM_TO_MEM, i,
+                                                src + offset, dest + offset,
+                                                xfer_count, ctcr, ctbr,
+                                                i == count - 1, i == 0, false);
+                }
+        }
+
+        desc->ccr = ccr;
+
+        desc->cyclic = false;
+
+        return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
+static void stm32_mdma_dump_reg(struct stm32_mdma_chan *chan)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+
+        dev_dbg(chan2dev(chan), "CCR:     0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)));
+        dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)));
+        dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)));
+        dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CSAR(chan->id)));
+        dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CDAR(chan->id)));
+        dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CBRUR(chan->id)));
+        dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)));
+        dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)));
+        dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CMAR(chan->id)));
+        dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n",
+                stm32_mdma_read(dmadev, STM32_MDMA_CMDR(chan->id)));
+}
+
+static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct virt_dma_desc *vdesc;
+        struct stm32_mdma_hwdesc *hwdesc;
+        u32 id = chan->id;
+        u32 status, reg;
+
+        vdesc = vchan_next_desc(&chan->vchan);
+        if (!vdesc) {
+                chan->desc = NULL;
+                return;
+        }
+
+        chan->desc = to_stm32_mdma_desc(vdesc);
+        hwdesc = chan->desc->hwdesc;
+        chan->curr_hwdesc = 0;
+
+        stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
+        stm32_mdma_write(dmadev, STM32_MDMA_CTCR(id), hwdesc->ctcr);
+        stm32_mdma_write(dmadev, STM32_MDMA_CBNDTR(id), hwdesc->cbndtr);
+        stm32_mdma_write(dmadev, STM32_MDMA_CSAR(id), hwdesc->csar);
+        stm32_mdma_write(dmadev, STM32_MDMA_CDAR(id), hwdesc->cdar);
+        stm32_mdma_write(dmadev, STM32_MDMA_CBRUR(id), hwdesc->cbrur);
+        stm32_mdma_write(dmadev, STM32_MDMA_CLAR(id), hwdesc->clar);
+        stm32_mdma_write(dmadev, STM32_MDMA_CTBR(id), hwdesc->ctbr);
+        stm32_mdma_write(dmadev, STM32_MDMA_CMAR(id), hwdesc->cmar);
+        stm32_mdma_write(dmadev, STM32_MDMA_CMDR(id), hwdesc->cmdr);
+
+        /* Clear interrupt status if it is there */
+        status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
+        if (status)
+                stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(id), status);
+
+        stm32_mdma_dump_reg(chan);
+
+        /* Start DMA */
+        stm32_mdma_set_bits(dmadev, STM32_MDMA_CCR(id), STM32_MDMA_CCR_EN);
+
+        /* Set SW request in case of MEM2MEM transfer */
+        if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM) {
+                reg = STM32_MDMA_CCR(id);
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
+        }
+
+        chan->busy = true;
+
+        dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
+}
+
+static void stm32_mdma_issue_pending(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        unsigned long flags;
+
+        spin_lock_irqsave(&chan->vchan.lock, flags);
+
+        if (!vchan_issue_pending(&chan->vchan))
+                goto end;
+
+        dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
+
+        if (!chan->desc && !chan->busy)
+                stm32_mdma_start_transfer(chan);
+
+end:
+        spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static int stm32_mdma_pause(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&chan->vchan.lock, flags);
+        ret = stm32_mdma_disable_chan(chan);
+        spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+        if (!ret)
+                dev_dbg(chan2dev(chan), "vchan %p: pause\n", &chan->vchan);
+
+        return ret;
+}
+
+static int stm32_mdma_resume(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct stm32_mdma_hwdesc *hwdesc;
+        unsigned long flags;
+        u32 status, reg;
+
+        hwdesc = &chan->desc->hwdesc[chan->curr_hwdesc];
+
+        spin_lock_irqsave(&chan->vchan.lock, flags);
+
+        /* Re-configure control register */
+        stm32_mdma_write(dmadev, STM32_MDMA_CCR(chan->id), chan->desc->ccr);
+
+        /* Clear interrupt status if it is there */
+        status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
+        if (status)
+                stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
+
+        stm32_mdma_dump_reg(chan);
+
+        /* Re-start DMA */
+        reg = STM32_MDMA_CCR(chan->id);
+        stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_EN);
+
+        /* Set SW request in case of MEM2MEM transfer */
+        if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM)
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
+
+        spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+        dev_dbg(chan2dev(chan), "vchan %p: resume\n", &chan->vchan);
+
+        return 0;
+}
+
+static int stm32_mdma_terminate_all(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        unsigned long flags;
+        LIST_HEAD(head);
+
+        spin_lock_irqsave(&chan->vchan.lock, flags);
+        if (chan->busy) {
+                stm32_mdma_stop(chan);
+                chan->desc = NULL;
+        }
+        vchan_get_all_descriptors(&chan->vchan, &head);
+        spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+        vchan_dma_desc_free_list(&chan->vchan, &head);
+
+        return 0;
+}
+
+static void stm32_mdma_synchronize(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+
+        vchan_synchronize(&chan->vchan);
+}
+
+static int stm32_mdma_slave_config(struct dma_chan *c,
+                                   struct dma_slave_config *config)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+
+        memcpy(&chan->dma_config, config, sizeof(*config));
+
+        return 0;
+}
+
+static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
+                                      struct stm32_mdma_desc *desc,
+                                      u32 curr_hwdesc)
+{
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        struct stm32_mdma_hwdesc *hwdesc = desc->hwdesc;
+        u32 cbndtr, residue, modulo, burst_size;
+        int i;
+
+        residue = 0;
+        for (i = curr_hwdesc + 1; i < desc->count; i++) {
+                hwdesc = &desc->hwdesc[i];
+                residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
+        }
+        cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
+        residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
+
+        if (!chan->mem_burst)
+                return residue;
+
+        burst_size = chan->mem_burst * chan->mem_width;
+        modulo = residue % burst_size;
+        if (modulo)
+                residue = residue - modulo + burst_size;
+
+        return residue;
+}
+
+static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
+                                            dma_cookie_t cookie,
+                                            struct dma_tx_state *state)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct virt_dma_desc *vdesc;
+        enum dma_status status;
+        unsigned long flags;
+        u32 residue = 0;
+
+        status = dma_cookie_status(c, cookie, state);
+        if ((status == DMA_COMPLETE) || (!state))
+                return status;
+
+        spin_lock_irqsave(&chan->vchan.lock, flags);
+
+        vdesc = vchan_find_desc(&chan->vchan, cookie);
+        if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
+                residue = stm32_mdma_desc_residue(chan, chan->desc,
+                                                  chan->curr_hwdesc);
+        else if (vdesc)
+                residue = stm32_mdma_desc_residue(chan,
+                                                  to_stm32_mdma_desc(vdesc), 0);
+        dma_set_residue(state, residue);
+
+        spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+        return status;
+}
+
+static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
+{
+        list_del(&chan->desc->vdesc.node);
+        vchan_cookie_complete(&chan->desc->vdesc);
+        chan->desc = NULL;
+        chan->busy = false;
+
+        /* Start the next transfer if this driver has a next desc */
+        stm32_mdma_start_transfer(chan);
+}
+
+static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
+{
+        struct stm32_mdma_device *dmadev = devid;
+        struct stm32_mdma_chan *chan = devid;
+        u32 reg, id, ien, status, flag;
+
+        /* Find out which channel generates the interrupt */
+        status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
+        if (status) {
+                id = __ffs(status);
+        } else {
+                status = readl_relaxed(dmadev->base + STM32_MDMA_GISR1);
+                if (!status) {
+                        dev_dbg(mdma2dev(dmadev), "spurious it\n");
+                        return IRQ_NONE;
+                }
+                id = __ffs(status);
+                /*
+                 * As GISR0 provides status for channel id from 0 to 31,
+                 * so GISR1 provides status for channel id from 32 to 62
+                 */
+                id += 32;
+        }
+
+        chan = &dmadev->chan[id];
+        if (!chan) {
+                dev_err(chan2dev(chan), "MDMA channel not initialized\n");
+                goto exit;
+        }
+
+        /* Handle interrupt for the channel */
+        spin_lock(&chan->vchan.lock);
+        status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
+        ien = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
+        ien &= STM32_MDMA_CCR_IRQ_MASK;
+        ien >>= 1;
+
+        if (!(status & ien)) {
+                spin_unlock(&chan->vchan.lock);
+                dev_dbg(chan2dev(chan),
+                        "spurious it (status=0x%04x, ien=0x%04x)\n",
+                        status, ien);
+                return IRQ_NONE;
+        }
+
+        flag = __ffs(status & ien);
+        reg = STM32_MDMA_CIFCR(chan->id);
+
+        switch (1 << flag) {
+        case STM32_MDMA_CISR_TEIF:
+                id = chan->id;
+                status = readl_relaxed(dmadev->base + STM32_MDMA_CESR(id));
+                dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n", status);
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
+                break;
+
+        case STM32_MDMA_CISR_CTCIF:
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
+                stm32_mdma_xfer_end(chan);
+                break;
+
+        case STM32_MDMA_CISR_BRTIF:
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
+                break;
+
+        case STM32_MDMA_CISR_BTIF:
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
+                chan->curr_hwdesc++;
+                if (chan->desc && chan->desc->cyclic) {
+                        if (chan->curr_hwdesc == chan->desc->count)
+                                chan->curr_hwdesc = 0;
+                        vchan_cyclic_callback(&chan->desc->vdesc);
+                }
+                break;
+
+        case STM32_MDMA_CISR_TCIF:
+                stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
+                break;
+
+        default:
+                dev_err(chan2dev(chan), "it %d unhandled (status=0x%04x)\n",
+                        1 << flag, status);
+        }
+
+        spin_unlock(&chan->vchan.lock);
+
+exit:
+        return IRQ_HANDLED;
+}
+
+static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        int ret;
+
+        chan->desc_pool = dmam_pool_create(dev_name(&c->dev->device),
+                                           c->device->dev,
+                                           sizeof(struct stm32_mdma_hwdesc),
+                                          __alignof__(struct stm32_mdma_hwdesc),
+                                           0);
+        if (!chan->desc_pool) {
+                dev_err(chan2dev(chan), "failed to allocate descriptor pool\n");
+                return -ENOMEM;
+        }
+
+        ret = clk_prepare_enable(dmadev->clk);
+        if (ret < 0) {
+                dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
+                return ret;
+        }
+
+        ret = stm32_mdma_disable_chan(chan);
+        if (ret < 0)
+                clk_disable_unprepare(dmadev->clk);
+
+        return ret;
+}
+
+static void stm32_mdma_free_chan_resources(struct dma_chan *c)
+{
+        struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
+        struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
+        unsigned long flags;
+
+        dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
+
+        if (chan->busy) {
+                spin_lock_irqsave(&chan->vchan.lock, flags);
+                stm32_mdma_stop(chan);
+                chan->desc = NULL;
+                spin_unlock_irqrestore(&chan->vchan.lock, flags);
+        }
+
+        clk_disable_unprepare(dmadev->clk);
+        vchan_free_chan_resources(to_virt_chan(c));
+        dmam_pool_destroy(chan->desc_pool);
+        chan->desc_pool = NULL;
+}
+
+static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
+                                            struct of_dma *ofdma)
+{
+        struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
+        struct stm32_mdma_chan *chan;
+        struct dma_chan *c;
+        struct stm32_mdma_chan_config config;
+
+        if (dma_spec->args_count < 5) {
+                dev_err(mdma2dev(dmadev), "Bad number of args\n");
+                return NULL;
+        }
+
+        config.request = dma_spec->args[0];
+        config.priority_level = dma_spec->args[1];
+        config.transfer_config = dma_spec->args[2];
+        config.mask_addr = dma_spec->args[3];
+        config.mask_data = dma_spec->args[4];
+
+        if (config.request >= dmadev->nr_requests) {
+                dev_err(mdma2dev(dmadev), "Bad request line\n");
+                return NULL;
+        }
+
+        if (config.priority_level > STM32_MDMA_VERY_HIGH_PRIORITY) {
+                dev_err(mdma2dev(dmadev), "Priority level not supported\n");
+                return NULL;
+        }
+
+        c = dma_get_any_slave_channel(&dmadev->ddev);
+        if (!c) {
+                dev_err(mdma2dev(dmadev), "No more channel avalaible\n");
+                return NULL;
+        }
+
+        chan = to_stm32_mdma_chan(c);
+        chan->chan_config = config;
+
+        return c;
+}
+
+static const struct of_device_id stm32_mdma_of_match[] = {
+        { .compatible = "st,stm32h7-mdma", },
+        { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_mdma_of_match);
+
+static int stm32_mdma_probe(struct platform_device *pdev)
+{
+        struct stm32_mdma_chan *chan;
+        struct stm32_mdma_device *dmadev;
+        struct dma_device *dd;
+        struct device_node *of_node;
+        struct resource *res;
+        u32 nr_channels, nr_requests;
+        int i, count, ret;
+
+        of_node = pdev->dev.of_node;
+        if (!of_node)
+                return -ENODEV;
+
+        ret = device_property_read_u32(&pdev->dev, "dma-channels",
+                                       &nr_channels);
+        if (ret) {
+                nr_channels = STM32_MDMA_MAX_CHANNELS;
+                dev_warn(&pdev->dev, "MDMA defaulting on %i channels\n",
+                         nr_channels);
+        }
+
+        ret = device_property_read_u32(&pdev->dev, "dma-requests",
+                                       &nr_requests);
+        if (ret) {
+                nr_requests = STM32_MDMA_MAX_REQUESTS;
+                dev_warn(&pdev->dev, "MDMA defaulting on %i request lines\n",
+                         nr_requests);
+        }
+
+        count = device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
+                                               NULL, 0);
+        if (count < 0)
+                count = 0;
+
+        dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev) + sizeof(u32) * count,
+                              GFP_KERNEL);
+        if (!dmadev)
+                return -ENOMEM;
+
+        dmadev->nr_channels = nr_channels;
+        dmadev->nr_requests = nr_requests;
+        device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
+                                       dmadev->ahb_addr_masks,
+                                       count);
+        dmadev->nr_ahb_addr_masks = count;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        dmadev->base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(dmadev->base))
+                return PTR_ERR(dmadev->base);
+
+        dmadev->clk = devm_clk_get(&pdev->dev, NULL);
+        if (IS_ERR(dmadev->clk)) {
+                ret = PTR_ERR(dmadev->clk);
+                if (ret == -EPROBE_DEFER)
+                        dev_info(&pdev->dev, "Missing controller clock\n");
+                return ret;
+        }
+
+        dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
+        if (!IS_ERR(dmadev->rst)) {
+                reset_control_assert(dmadev->rst);
+                udelay(2);
+                reset_control_deassert(dmadev->rst);
+        }
+
+        dd = &dmadev->ddev;
+        dma_cap_set(DMA_SLAVE, dd->cap_mask);
+        dma_cap_set(DMA_PRIVATE, dd->cap_mask);
+        dma_cap_set(DMA_CYCLIC, dd->cap_mask);
+        dma_cap_set(DMA_MEMCPY, dd->cap_mask);
+        dd->device_alloc_chan_resources = stm32_mdma_alloc_chan_resources;
+        dd->device_free_chan_resources = stm32_mdma_free_chan_resources;
+        dd->device_tx_status = stm32_mdma_tx_status;
+        dd->device_issue_pending = stm32_mdma_issue_pending;
+        dd->device_prep_slave_sg = stm32_mdma_prep_slave_sg;
+        dd->device_prep_dma_cyclic = stm32_mdma_prep_dma_cyclic;
+        dd->device_prep_dma_memcpy = stm32_mdma_prep_dma_memcpy;
+        dd->device_config = stm32_mdma_slave_config;
+        dd->device_pause = stm32_mdma_pause;
+        dd->device_resume = stm32_mdma_resume;
+        dd->device_terminate_all = stm32_mdma_terminate_all;
+        dd->device_synchronize = stm32_mdma_synchronize;
+        dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+                BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+                BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
+                BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
+        dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+                BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+                BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
+                BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
+        dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
+                BIT(DMA_MEM_TO_MEM);
+        dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+        dd->max_burst = STM32_MDMA_MAX_BURST;
+        dd->dev = &pdev->dev;
+        INIT_LIST_HEAD(&dd->channels);
+
+        for (i = 0; i < dmadev->nr_channels; i++) {
+                chan = &dmadev->chan[i];
+                chan->id = i;
+                chan->vchan.desc_free = stm32_mdma_desc_free;
+                vchan_init(&chan->vchan, dd);
+        }
+
+        dmadev->irq = platform_get_irq(pdev, 0);
+        if (dmadev->irq < 0) {
+                dev_err(&pdev->dev, "failed to get IRQ\n");
+                return dmadev->irq;
+        }
+
+        ret = devm_request_irq(&pdev->dev, dmadev->irq, stm32_mdma_irq_handler,
+                               0, dev_name(&pdev->dev), dmadev);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to request IRQ\n");
+                return ret;
+        }
+
+        ret = dma_async_device_register(dd);
+        if (ret)
+                return ret;
+
+        ret = of_dma_controller_register(of_node, stm32_mdma_of_xlate, dmadev);
+        if (ret < 0) {
+                dev_err(&pdev->dev,
+                        "STM32 MDMA DMA OF registration failed %d\n", ret);
+                goto err_unregister;
+        }
+
+        platform_set_drvdata(pdev, dmadev);
+
+        dev_info(&pdev->dev, "STM32 MDMA driver registered\n");
+
+        return 0;
+
+err_unregister:
+        dma_async_device_unregister(dd);
+
+        return ret;
+}
+
+static struct platform_driver stm32_mdma_driver = {
+        .probe = stm32_mdma_probe,
+        .driver = {
+                .name = "stm32-mdma",
+                .of_match_table = stm32_mdma_of_match,
+        },
+};
+
+static int __init stm32_mdma_init(void)
+{
+        return platform_driver_register(&stm32_mdma_driver);
+}
+
+subsys_initcall(stm32_mdma_init);
+
+MODULE_DESCRIPTION("Driver for STM32 MDMA controller");
+MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
+MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
+MODULE_LICENSE("GPL v2");