This V4L2 subdev driver enables Digital Camera Memory Interface (DCMI)
of STMicroelectronics STM32 SoC series.

Signed-off-by: Yannick Fertre <yannick.fer...@st.com>
Signed-off-by: Hugues Fruchet <hugues.fruc...@st.com>
---
 drivers/media/platform/Kconfig            |   12 +
 drivers/media/platform/Makefile           |    2 +
 drivers/media/platform/stm32/Makefile     |    1 +
 drivers/media/platform/stm32/stm32-dcmi.c | 1417 +++++++++++++++++++++++++++++
 4 files changed, 1432 insertions(+)
 create mode 100644 drivers/media/platform/stm32/Makefile
 create mode 100644 drivers/media/platform/stm32/stm32-dcmi.c

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index ab0bb48..3421965 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -114,6 +114,18 @@ config VIDEO_S3C_CAMIF
          To compile this driver as a module, choose M here: the module
          will be called s3c-camif.
 
+config VIDEO_STM32_DCMI
+       tristate "Digital Camera Memory Interface (DCMI) support"
+       depends on VIDEO_V4L2 && OF && HAS_DMA
+       depends on ARCH_STM32 || COMPILE_TEST
+       select VIDEOBUF2_DMA_CONTIG
+       ---help---
+         This module makes the STM32 Digital Camera Memory Interface (DCMI)
+         available as a v4l2 device.
+
+         To compile this driver as a module, choose M here: the module
+         will be called stm32-dcmi.
+
 source "drivers/media/platform/soc_camera/Kconfig"
 source "drivers/media/platform/exynos4-is/Kconfig"
 source "drivers/media/platform/am437x/Kconfig"
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 8959f6e..d747715 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -64,6 +64,8 @@ obj-$(CONFIG_VIDEO_RCAR_VIN)          += rcar-vin/
 
 obj-$(CONFIG_VIDEO_ATMEL_ISC)          += atmel/
 
+obj-$(CONFIG_VIDEO_STM32_DCMI)         += stm32/
+
 ccflags-y += -I$(srctree)/drivers/media/i2c
 
 obj-$(CONFIG_VIDEO_MEDIATEK_VPU)       += mtk-vpu/
diff --git a/drivers/media/platform/stm32/Makefile 
b/drivers/media/platform/stm32/Makefile
new file mode 100644
index 0000000..9b606a7
--- /dev/null
+++ b/drivers/media/platform/stm32/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_VIDEO_STM32_DCMI) += stm32-dcmi.o
diff --git a/drivers/media/platform/stm32/stm32-dcmi.c 
b/drivers/media/platform/stm32/stm32-dcmi.c
new file mode 100644
index 0000000..2f0286b
--- /dev/null
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -0,0 +1,1417 @@
+/*
+ * Driver for STM32 Digital Camera Memory Interface
+ *
+ * Copyright (C) STMicroelectronics SA 2017
+ * Authors: Yannick Fertre <yannick.fer...@st.com>
+ *          Hugues Fruchet <hugues.fruc...@st.com>
+ *          for STMicroelectronics.
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * This driver is based on atmel_isi.c
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-image-sizes.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-of.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define DRV_NAME "stm32-dcmi"
+
+/* Registers offset for DCMI */
+#define DCMI_CR                0x00 /* Control Register */
+#define DCMI_SR                0x04 /* Status Register */
+#define DCMI_RIS       0x08 /* Raw Interrupt Status register */
+#define DCMI_IER       0x0C /* Interrupt Enable Register */
+#define DCMI_MIS       0x10 /* Masked Interrupt Status register */
+#define DCMI_ICR       0x14 /* Interrupt Clear Register */
+#define DCMI_ESCR      0x18 /* Embedded Synchronization Code Register */
+#define DCMI_ESUR      0x1C /* Embedded Synchronization Unmask Register */
+#define DCMI_CWSTRT    0x20 /* Crop Window STaRT */
+#define DCMI_CWSIZE    0x24 /* Crop Window SIZE */
+#define DCMI_DR                0x28 /* Data Register */
+#define DCMI_IDR       0x2c /* IDentifier Register */
+
+/* Bits definition for control register (DCMI_CR) */
+#define CR_CAPTURE     BIT(0)
+#define CR_CM          BIT(1)
+#define CR_CROP                BIT(2)
+#define CR_JPEG                BIT(3)
+#define CR_ESS         BIT(4)
+#define CR_PCKPOL      BIT(5)
+#define CR_HSPOL       BIT(6)
+#define CR_VSPOL       BIT(7)
+#define CR_FCRC_0      BIT(8)
+#define CR_FCRC_1      BIT(9)
+#define CR_EDM_0       BIT(10)
+#define CR_EDM_1       BIT(11)
+#define CR_ENABLE      BIT(14)
+
+/* Bits definition for status register (DCMI_SR) */
+#define SR_HSYNC       BIT(0)
+#define SR_VSYNC       BIT(1)
+#define SR_FNE         BIT(2)
+
+/*
+ * Bits definition for interrupt registers
+ * (DCMI_RIS, DCMI_IER, DCMI_MIS, DCMI_ICR)
+ */
+#define IT_FRAME       BIT(0)
+#define IT_OVR         BIT(1)
+#define IT_ERR         BIT(2)
+#define IT_VSYNC       BIT(3)
+#define IT_LINE                BIT(4)
+
+enum state {
+       STOPPED = 0,
+       RUNNING,
+       STOPPING,
+};
+
+#define MAX_BUS_WIDTH          14
+#define MAX_SUPPORT_WIDTH      2048
+#define MAX_SUPPORT_HEIGHT     2048
+#define MIN_SUPPORT_WIDTH      16
+#define MIN_SUPPORT_HEIGHT     16
+#define TIMEOUT_MS             1000
+
+struct dcmi_graph_entity {
+       struct device_node *node;
+
+       struct v4l2_async_subdev asd;
+       struct v4l2_subdev *subdev;
+};
+
+struct dcmi_format {
+       u32     fourcc;
+       u32     mbus_code;
+       u8      bpp;
+};
+
+struct dcmi_buf {
+       struct vb2_v4l2_buffer  vb;
+       bool                    prepared;
+       dma_addr_t              paddr;
+       size_t                  size;
+       struct list_head        list;
+};
+
+struct stm32_dcmi {
+       spinlock_t                      irqlock;
+       struct device                   *dev;
+       void __iomem                    *regs;
+       struct resource                 *res;
+       struct reset_control            *rstc;
+       int                             sequence;
+       struct list_head                buffers;
+       struct dcmi_buf                 *active;
+
+       struct v4l2_device              v4l2_dev;
+       struct video_device             *vdev;
+       struct v4l2_async_notifier      notifier;
+       struct dcmi_graph_entity        entity;
+       struct v4l2_format              fmt;
+
+       const struct dcmi_format        **user_formats;
+       unsigned int                    num_user_formats;
+       const struct dcmi_format        *current_fmt;
+
+       struct mutex                    lock;
+       struct vb2_queue                queue;
+
+       struct v4l2_of_bus_parallel     bus;
+       struct completion               complete;
+       struct clk                      *mclk;
+       enum state                      state;
+       struct dma_chan                 *dma_chan;
+       dma_cookie_t                    dma_cookie;
+       u32                             misr;
+       int                             errors_count;
+       int                             buffers_count;
+};
+
+static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier 
*n)
+{
+       return container_of(n, struct stm32_dcmi, notifier);
+}
+
+static inline u32 reg_read(void __iomem *base, u32 reg)
+{
+       return readl_relaxed(base + reg);
+}
+
+static inline void reg_write(void __iomem *base, u32 reg, u32 val)
+{
+       writel_relaxed(val, base + reg);
+}
+
+static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
+{
+       reg_write(base, reg, reg_read(base, reg) | mask);
+}
+
+static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
+{
+       reg_write(base, reg, reg_read(base, reg) & ~mask);
+}
+
+static int dcmi_start_capture(struct stm32_dcmi *dcmi);
+
+static void dcmi_dma_callback(void *param)
+{
+       struct stm32_dcmi *dcmi = (struct stm32_dcmi *)param;
+       struct dma_chan *chan = dcmi->dma_chan;
+       struct dma_tx_state state;
+       enum dma_status status;
+
+       spin_lock(&dcmi->irqlock);
+
+       /* Check DMA status */
+       status = dmaengine_tx_status(chan, dcmi->dma_cookie, &state);
+
+       switch (status) {
+       case DMA_IN_PROGRESS:
+               dev_dbg(dcmi->dev, "%s: Received DMA_IN_PROGRESS\n", __func__);
+               break;
+       case DMA_PAUSED:
+               dev_err(dcmi->dev, "%s: Received DMA_PAUSED\n", __func__);
+               break;
+       case DMA_ERROR:
+               dev_err(dcmi->dev, "%s: Received DMA_ERROR\n", __func__);
+               break;
+       case DMA_COMPLETE:
+               dev_dbg(dcmi->dev, "%s: Received DMA_COMPLETE\n", __func__);
+
+               if (dcmi->active) {
+                       struct dcmi_buf *buf = dcmi->active;
+                       struct vb2_v4l2_buffer *vbuf = &dcmi->active->vb;
+
+                       vbuf->sequence = dcmi->sequence++;
+                       vbuf->field = V4L2_FIELD_NONE;
+                       vbuf->vb2_buf.timestamp = ktime_get_ns();
+                       vb2_set_plane_payload(&vbuf->vb2_buf, 0, buf->size);
+                       vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
+                       dev_dbg(dcmi->dev, "buffer[%d] done seq=%d\n",
+                               vbuf->vb2_buf.index, vbuf->sequence);
+
+                       dcmi->buffers_count++;
+                       dcmi->active = NULL;
+               }
+
+               /* Restart a new DMA transfer with next buffer */
+               if (dcmi->state == RUNNING) {
+                       int ret;
+
+                       if (list_empty(&dcmi->buffers)) {
+                               dev_err(dcmi->dev, "%s: No more buffer queued, 
cannot capture buffer",
+                                       __func__);
+                               dcmi->errors_count++;
+                               dcmi->active = NULL;
+
+                               spin_unlock(&dcmi->irqlock);
+                               return;
+                       }
+
+                       dcmi->active = list_entry(dcmi->buffers.next,
+                                                 struct dcmi_buf, list);
+
+                       list_del_init(&dcmi->active->list);
+
+                       ret = dcmi_start_capture(dcmi);
+                       if (ret) {
+                               dev_err(dcmi->dev, "%s: Cannot restart capture 
on DMA complete",
+                                       __func__);
+
+                               spin_unlock(&dcmi->irqlock);
+                               return;
+                       }
+
+                       /* Enable capture */
+                       reg_set(dcmi->regs, DCMI_CR, CR_CAPTURE);
+               }
+
+               break;
+       default:
+               dev_err(dcmi->dev, "%s: Received unknown status\n", __func__);
+               break;
+       }
+
+       spin_unlock(&dcmi->irqlock);
+}
+
+static int dcmi_start_dma(struct stm32_dcmi *dcmi,
+                         struct dcmi_buf *buf)
+{
+       struct dma_async_tx_descriptor *desc = NULL;
+       struct dma_slave_config config;
+       int ret;
+
+       memset(&config, 0, sizeof(config));
+
+       config.src_addr = (dma_addr_t)dcmi->res->start + DCMI_DR;
+       config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+       config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+       config.dst_maxburst = 4;
+
+       /* Configure DMA channel */
+       ret = dmaengine_slave_config(dcmi->dma_chan, &config);
+       if (ret < 0) {
+               dev_err(dcmi->dev, "%s: DMA channel config failed (%d)\n",
+                       __func__, ret);
+               return ret;
+       }
+
+       /* Prepare a DMA transaction */
+       desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr,
+                                          buf->size,
+                                          DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
+       if (!desc) {
+               dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed 
for buffer size %zu\n",
+                       __func__, buf->size);
+               return -EINVAL;
+       }
+
+       /* Set completion callback routine for notification */
+       desc->callback = dcmi_dma_callback;
+       desc->callback_param = dcmi;
+
+       /* Push current DMA transaction in the pending queue */
+       dcmi->dma_cookie = dmaengine_submit(desc);
+
+       dma_async_issue_pending(dcmi->dma_chan);
+
+       return 0;
+}
+
+static int dcmi_start_capture(struct stm32_dcmi *dcmi)
+{
+       int ret;
+       struct dcmi_buf *buf = dcmi->active;
+
+       if (!buf)
+               return -EINVAL;
+
+       ret = dcmi_start_dma(dcmi, buf);
+       if (ret) {
+               vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+               dcmi->errors_count++;
+               dcmi->active = NULL;
+
+               return ret;
+       }
+
+       /* Enable capture */
+       reg_set(dcmi->regs, DCMI_CR, CR_CAPTURE);
+
+       return 0;
+}
+
+static irqreturn_t dcmi_irq_thread(int irq, void *arg)
+{
+       struct stm32_dcmi *dcmi = arg;
+       int ret;
+
+       spin_lock(&dcmi->irqlock);
+
+       /* Stop capture is required */
+       if (dcmi->state == STOPPING) {
+               reg_clear(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
+
+               dcmi->state = STOPPED;
+
+               complete(&dcmi->complete);
+
+               spin_unlock(&dcmi->irqlock);
+               return IRQ_HANDLED;
+       }
+
+       if ((dcmi->misr & IT_OVR) || (dcmi->misr & IT_ERR)) {
+               /*
+                * An overflow or an error has been detected,
+                * stop current DMA transfert & restart it
+                */
+               dev_warn(dcmi->dev, "%s: Overflow or error detected\n",
+                        __func__);
+
+               dcmi->errors_count++;
+               dmaengine_terminate_all(dcmi->dma_chan);
+
+               reg_set(dcmi->regs, DCMI_ICR, IT_FRAME | IT_OVR | IT_ERR);
+
+               dev_dbg(dcmi->dev, "Restarting capture after DCMI error\n");
+
+               ret = dcmi_start_capture(dcmi);
+               if (ret) {
+                       dev_err(dcmi->dev, "%s: Cannot restart capture on 
overflow or error\n",
+                               __func__);
+
+                       spin_unlock(&dcmi->irqlock);
+                       return IRQ_HANDLED;
+               }
+       }
+
+       spin_unlock(&dcmi->irqlock);
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t dcmi_irq_callback(int irq, void *arg)
+{
+       struct stm32_dcmi *dcmi = arg;
+
+       spin_lock(&dcmi->irqlock);
+
+       dcmi->misr = reg_read(dcmi->regs, DCMI_MIS);
+
+       /* Clear interrupt */
+       reg_set(dcmi->regs, DCMI_ICR, IT_FRAME | IT_OVR | IT_ERR);
+
+       spin_unlock(&dcmi->irqlock);
+
+       return IRQ_WAKE_THREAD;
+}
+
+static int dcmi_queue_setup(struct vb2_queue *vq,
+                           unsigned int *nbuffers,
+                           unsigned int *nplanes,
+                           unsigned int sizes[],
+                           struct device *alloc_devs[])
+{
+       struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
+       unsigned long size;
+
+       size = dcmi->fmt.fmt.pix.sizeimage;
+
+       /* Make sure the image size is large enough */
+       if (*nplanes)
+               return sizes[0] < size ? -EINVAL : 0;
+
+       *nplanes = 1;
+       sizes[0] = size;
+
+       dcmi->active = NULL;
+
+       dev_dbg(dcmi->dev, "Setup queue, count=%d, size=%ld\n",
+               *nbuffers, size);
+
+       return 0;
+}
+
+static int dcmi_buf_init(struct vb2_buffer *vb)
+{
+       struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+       struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
+
+       INIT_LIST_HEAD(&buf->list);
+
+       return 0;
+}
+
+static int dcmi_buf_prepare(struct vb2_buffer *vb)
+{
+       struct stm32_dcmi *dcmi =  vb2_get_drv_priv(vb->vb2_queue);
+       struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+       struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
+       unsigned long size;
+
+       size = dcmi->fmt.fmt.pix.sizeimage;
+
+       if (vb2_plane_size(vb, 0) < size) {
+               dev_err(dcmi->dev, "%s data will not fit into plane (%lu < 
%lu)\n",
+                       __func__, vb2_plane_size(vb, 0), size);
+               return -EINVAL;
+       }
+
+       vb2_set_plane_payload(vb, 0, size);
+
+       if (!buf->prepared) {
+               /* Get memory addresses */
+               buf->paddr =
+                       vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
+               buf->size = vb2_plane_size(&buf->vb.vb2_buf, 0);
+               buf->prepared = true;
+
+               vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->size);
+
+               dev_dbg(dcmi->dev, "buffer[%d] phy=0x%pad size=%zu\n",
+                       vb->index, &buf->paddr, buf->size);
+       }
+
+       return 0;
+}
+
+static void dcmi_buf_queue(struct vb2_buffer *vb)
+{
+       struct stm32_dcmi *dcmi =  vb2_get_drv_priv(vb->vb2_queue);
+       struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+       struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
+       unsigned long flags = 0;
+
+       spin_lock_irqsave(&dcmi->irqlock, flags);
+
+       if ((dcmi->state == RUNNING) && (!dcmi->active)) {
+               int ret;
+
+               dcmi->active = buf;
+
+               dev_dbg(dcmi->dev, "Starting capture on buffer[%d] queued\n",
+                       buf->vb.vb2_buf.index);
+
+               ret = dcmi_start_capture(dcmi);
+               if (ret) {
+                       dev_err(dcmi->dev, "%s: Cannot restart capture on 
overflow or error\n",
+                               __func__);
+
+                       spin_unlock_irqrestore(&dcmi->irqlock, flags);
+                       return;
+               }
+       } else {
+               /* Enqueue to video buffers list */
+               list_add_tail(&buf->list, &dcmi->buffers);
+       }
+
+       spin_unlock_irqrestore(&dcmi->irqlock, flags);
+}
+
+static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+       struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
+       struct dcmi_buf *buf, *node;
+       u32 val;
+       int ret;
+
+       /* Enable stream on the sub device */
+       ret = v4l2_subdev_call(dcmi->entity.subdev, video, s_stream, 1);
+       if (ret && ret != -ENOIOCTLCMD) {
+               dev_err(dcmi->dev, "%s: Failed to start streaming, subdev 
streamon error",
+                       __func__);
+               goto err_release_buffers;
+       }
+
+       if (clk_enable(dcmi->mclk)) {
+               dev_err(dcmi->dev, "%s: Failed to start streaming, cannot 
enable clock",
+                       __func__);
+               goto err_subdev_streamoff;
+       }
+
+       spin_lock_irq(&dcmi->irqlock);
+
+       val = reg_read(dcmi->regs, DCMI_CR);
+
+       val &= ~(CR_PCKPOL | CR_HSPOL | CR_VSPOL |
+                CR_EDM_0 | CR_EDM_1 | CR_FCRC_0 |
+                CR_FCRC_1 | CR_JPEG | CR_ESS);
+
+       /* Set bus width */
+       switch (dcmi->bus.bus_width) {
+       case 14:
+               val &= CR_EDM_0 + CR_EDM_1;
+               break;
+       case 12:
+               val &= CR_EDM_1;
+               break;
+       case 10:
+               val &= CR_EDM_0;
+               break;
+       default:
+               /* Set bus width to 8 bits by default */
+               break;
+       }
+
+       /* Set vertical synchronization polarity */
+       if (dcmi->bus.flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
+               val |= CR_VSPOL;
+
+       /* Set horizontal synchronization polarity */
+       if (dcmi->bus.flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
+               val |= CR_HSPOL;
+
+       /* Set pixel clock polarity */
+       if (dcmi->bus.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
+               val |= CR_PCKPOL;
+
+       reg_write(dcmi->regs, DCMI_CR, val);
+
+       /* Enable dcmi */
+       reg_set(dcmi->regs, DCMI_CR, CR_ENABLE);
+
+       dcmi->state = RUNNING;
+
+       dcmi->sequence = 0;
+       dcmi->errors_count = 0;
+       dcmi->buffers_count = 0;
+       dcmi->active = NULL;
+
+       /*
+        * Start transfer if at least one buffer has been queued,
+        * otherwise transfer is defered at buffer queueing
+        */
+       if (list_empty(&dcmi->buffers)) {
+               dev_dbg(dcmi->dev, "Start streaming is defered to next buffer 
queueing\n");
+               spin_unlock_irq(&dcmi->irqlock);
+               return 0;
+       }
+
+       dcmi->active = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
+       list_del_init(&dcmi->active->list);
+
+       /* Enable interruptions */
+       reg_set(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
+
+       dev_dbg(dcmi->dev, "Start streaming, starting capture\n");
+
+       ret = dcmi_start_capture(dcmi);
+       if (ret) {
+               dev_err(dcmi->dev, "%s: Start streaming failed, cannot start 
capture",
+                       __func__);
+
+               spin_unlock_irq(&dcmi->irqlock);
+               goto err_subdev_streamoff;
+       }
+
+       spin_unlock_irq(&dcmi->irqlock);
+
+       return 0;
+
+err_subdev_streamoff:
+       v4l2_subdev_call(dcmi->entity.subdev, video, s_stream, 0);
+
+err_release_buffers:
+       spin_lock_irq(&dcmi->irqlock);
+       dcmi->active = NULL;
+       /*
+        * return all buffers to vb2 in QUEUED state.
+        * This will give ownership back to userspace
+        */
+       list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
+               list_del_init(&buf->list);
+               vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
+       }
+       spin_unlock_irq(&dcmi->irqlock);
+
+       return ret;
+}
+
+static void dcmi_stop_streaming(struct vb2_queue *vq)
+{
+       struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
+       struct dcmi_buf *buf, *node;
+       unsigned long time_ms = msecs_to_jiffies(TIMEOUT_MS);
+       long timeout;
+       int ret;
+
+       /* Disable stream on the sub device */
+       ret = v4l2_subdev_call(dcmi->entity.subdev, video, s_stream, 0);
+       if (ret && ret != -ENOIOCTLCMD)
+               dev_err(dcmi->dev, "stream off failed in subdev\n");
+
+       dcmi->state = STOPPING;
+
+       timeout = wait_for_completion_interruptible_timeout(&dcmi->complete,
+                                                           time_ms);
+
+       spin_lock_irq(&dcmi->irqlock);
+
+       /* Disable interruptions */
+       reg_clear(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
+
+       /* Disable DCMI */
+       reg_clear(dcmi->regs, DCMI_CR, CR_ENABLE);
+
+       if (!timeout) {
+               dev_err(dcmi->dev, "Timeout during stop streaming\n");
+               dcmi->state = STOPPED;
+       }
+
+       if (dcmi->active) {
+               buf = dcmi->active;
+               vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+               dcmi->active = NULL;
+       }
+
+       /* Release all queued buffers */
+       list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
+               list_del_init(&buf->list);
+               vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+       }
+
+       spin_unlock_irq(&dcmi->irqlock);
+
+       /* Stop all pending DMA operations */
+       dmaengine_terminate_all(dcmi->dma_chan);
+
+       clk_disable(dcmi->mclk);
+
+       dev_dbg(dcmi->dev, "Stop streaming, errors=%d buffers=%d\n",
+               dcmi->errors_count, dcmi->buffers_count);
+}
+
+static struct vb2_ops dcmi_video_qops = {
+       .queue_setup            = dcmi_queue_setup,
+       .buf_init               = dcmi_buf_init,
+       .buf_prepare            = dcmi_buf_prepare,
+       .buf_queue              = dcmi_buf_queue,
+       .start_streaming        = dcmi_start_streaming,
+       .stop_streaming         = dcmi_stop_streaming,
+       .wait_prepare           = vb2_ops_wait_prepare,
+       .wait_finish            = vb2_ops_wait_finish,
+};
+
+static int dcmi_g_fmt_vid_cap(struct file *file, void *priv,
+                             struct v4l2_format *fmt)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+
+       *fmt = dcmi->fmt;
+
+       return 0;
+}
+
+static const struct dcmi_format *find_format_by_fourcc(struct stm32_dcmi *dcmi,
+                                                      unsigned int fourcc)
+{
+       unsigned int num_formats = dcmi->num_user_formats;
+       const struct dcmi_format *fmt;
+       unsigned int i;
+
+       for (i = 0; i < num_formats; i++) {
+               fmt = dcmi->user_formats[i];
+               if (fmt->fourcc == fourcc)
+                       return fmt;
+       }
+
+       return NULL;
+}
+
+static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
+                       const struct dcmi_format **current_fmt)
+{
+       const struct dcmi_format *dcmi_fmt;
+       struct v4l2_pix_format *pixfmt = &f->fmt.pix;
+       struct v4l2_subdev_pad_config pad_cfg;
+       struct v4l2_subdev_format format = {
+               .which = V4L2_SUBDEV_FORMAT_TRY,
+       };
+       int ret;
+
+       if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+
+       dcmi_fmt = find_format_by_fourcc(dcmi, pixfmt->pixelformat);
+       if (!dcmi_fmt) {
+               dcmi_fmt = dcmi->user_formats[dcmi->num_user_formats - 1];
+               pixfmt->pixelformat = dcmi_fmt->fourcc;
+       }
+
+       /* Limit to hardware capabilities */
+       if (pixfmt->width > MAX_SUPPORT_WIDTH)
+               pixfmt->width = MAX_SUPPORT_WIDTH;
+       if (pixfmt->height > MAX_SUPPORT_HEIGHT)
+               pixfmt->height = MAX_SUPPORT_HEIGHT;
+       if (pixfmt->width < MIN_SUPPORT_WIDTH)
+               pixfmt->width = MIN_SUPPORT_WIDTH;
+       if (pixfmt->height < MIN_SUPPORT_HEIGHT)
+               pixfmt->height = MIN_SUPPORT_HEIGHT;
+
+       v4l2_fill_mbus_format(&format.format, pixfmt, dcmi_fmt->mbus_code);
+       ret = v4l2_subdev_call(dcmi->entity.subdev, pad, set_fmt,
+                              &pad_cfg, &format);
+       if (ret < 0)
+               return ret;
+
+       v4l2_fill_pix_format(pixfmt, &format.format);
+
+       pixfmt->field = V4L2_FIELD_NONE;
+       pixfmt->bytesperline = pixfmt->width * dcmi_fmt->bpp;
+       pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
+
+       if (current_fmt)
+               *current_fmt = dcmi_fmt;
+
+       return 0;
+}
+
+static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f)
+{
+       struct v4l2_subdev_format format = {
+               .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+       };
+       const struct dcmi_format *current_fmt;
+       int ret;
+
+       ret = dcmi_try_fmt(dcmi, f, &current_fmt);
+       if (ret)
+               return ret;
+
+       v4l2_fill_mbus_format(&format.format, &f->fmt.pix,
+                             current_fmt->mbus_code);
+       ret = v4l2_subdev_call(dcmi->entity.subdev, pad,
+                              set_fmt, NULL, &format);
+       if (ret < 0)
+               return ret;
+
+       dcmi->fmt = *f;
+       dcmi->current_fmt = current_fmt;
+
+       return 0;
+}
+
+static int dcmi_s_fmt_vid_cap(struct file *file, void *priv,
+                             struct v4l2_format *f)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+
+       if (vb2_is_streaming(&dcmi->queue))
+               return -EBUSY;
+
+       return dcmi_set_fmt(dcmi, f);
+}
+
+static int dcmi_try_fmt_vid_cap(struct file *file, void *priv,
+                               struct v4l2_format *f)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+
+       return dcmi_try_fmt(dcmi, f, NULL);
+}
+
+static int dcmi_enum_fmt_vid_cap(struct file *file, void  *priv,
+                                struct v4l2_fmtdesc *f)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+
+       if (f->index >= dcmi->num_user_formats)
+               return -EINVAL;
+
+       f->pixelformat = dcmi->user_formats[f->index]->fourcc;
+       return 0;
+}
+
+static int dcmi_querycap(struct file *file, void *priv,
+                        struct v4l2_capability *cap)
+{
+       strlcpy(cap->driver, DRV_NAME, sizeof(cap->driver));
+       strlcpy(cap->card, "STM32 Digital Camera Memory Interface",
+               sizeof(cap->card));
+       strlcpy(cap->bus_info, "platform:dcmi", sizeof(cap->bus_info));
+       return 0;
+}
+
+static int dcmi_enum_input(struct file *file, void *priv,
+                          struct v4l2_input *i)
+{
+       if (i->index != 0)
+               return -EINVAL;
+
+       i->type = V4L2_INPUT_TYPE_CAMERA;
+       strlcpy(i->name, "Camera", sizeof(i->name));
+       return 0;
+}
+
+static int dcmi_g_input(struct file *file, void *priv, unsigned int *i)
+{
+       *i = 0;
+       return 0;
+}
+
+static int dcmi_s_input(struct file *file, void *priv, unsigned int i)
+{
+       if (i > 0)
+               return -EINVAL;
+       return 0;
+}
+
+static int dcmi_enum_framesizes(struct file *file, void *fh,
+                               struct v4l2_frmsizeenum *fsize)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+       const struct dcmi_format *dcmi_fmt;
+       struct v4l2_subdev_frame_size_enum fse = {
+               .index = fsize->index,
+               .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+       };
+       int ret;
+
+       dcmi_fmt = find_format_by_fourcc(dcmi, fsize->pixel_format);
+       if (!dcmi_fmt)
+               return -EINVAL;
+
+       fse.code = dcmi_fmt->mbus_code;
+
+       ret = v4l2_subdev_call(dcmi->entity.subdev, pad, enum_frame_size,
+                              NULL, &fse);
+       if (ret)
+               return ret;
+
+       fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+       fsize->discrete.width = fse.max_width;
+       fsize->discrete.height = fse.max_height;
+
+       return 0;
+}
+
+static int dcmi_enum_frameintervals(struct file *file, void *fh,
+                                   struct v4l2_frmivalenum *fival)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+       const struct dcmi_format *dcmi_fmt;
+       struct v4l2_subdev_frame_interval_enum fie = {
+               .index = fival->index,
+               .width = fival->width,
+               .height = fival->height,
+               .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+       };
+       int ret;
+
+       dcmi_fmt = find_format_by_fourcc(dcmi, fival->pixel_format);
+       if (!dcmi_fmt)
+               return -EINVAL;
+
+       fie.code = dcmi_fmt->mbus_code;
+
+       ret = v4l2_subdev_call(dcmi->entity.subdev, pad,
+                              enum_frame_interval, NULL, &fie);
+       if (ret)
+               return ret;
+
+       fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+       fival->discrete = fie.interval;
+
+       return 0;
+}
+
+static const struct of_device_id stm32_dcmi_of_match[] = {
+       { .compatible = "st,stm32-dcmi"},
+       { /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_dcmi_of_match);
+
+static int dcmi_open(struct file *file)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+       struct v4l2_subdev *sd = dcmi->entity.subdev;
+       int ret;
+
+       if (mutex_lock_interruptible(&dcmi->lock))
+               return -ERESTARTSYS;
+
+       ret = v4l2_fh_open(file);
+       if (ret < 0)
+               goto unlock;
+
+       if (!v4l2_fh_is_singular_file(file))
+               goto fh_rel;
+
+       ret = v4l2_subdev_call(sd, core, s_power, 1);
+       if (ret < 0 && ret != -ENOIOCTLCMD)
+               goto fh_rel;
+
+       ret = dcmi_set_fmt(dcmi, &dcmi->fmt);
+       if (ret)
+               v4l2_subdev_call(sd, core, s_power, 0);
+fh_rel:
+       if (ret)
+               v4l2_fh_release(file);
+unlock:
+       mutex_unlock(&dcmi->lock);
+       return ret;
+}
+
+static int dcmi_release(struct file *file)
+{
+       struct stm32_dcmi *dcmi = video_drvdata(file);
+       struct v4l2_subdev *sd = dcmi->entity.subdev;
+       bool fh_singular;
+       int ret;
+
+       mutex_lock(&dcmi->lock);
+
+       fh_singular = v4l2_fh_is_singular_file(file);
+
+       ret = _vb2_fop_release(file, NULL);
+
+       if (fh_singular)
+               v4l2_subdev_call(sd, core, s_power, 0);
+
+       mutex_unlock(&dcmi->lock);
+
+       return ret;
+}
+
+static const struct v4l2_ioctl_ops dcmi_ioctl_ops = {
+       .vidioc_querycap                = dcmi_querycap,
+
+       .vidioc_try_fmt_vid_cap         = dcmi_try_fmt_vid_cap,
+       .vidioc_g_fmt_vid_cap           = dcmi_g_fmt_vid_cap,
+       .vidioc_s_fmt_vid_cap           = dcmi_s_fmt_vid_cap,
+       .vidioc_enum_fmt_vid_cap        = dcmi_enum_fmt_vid_cap,
+
+       .vidioc_enum_input              = dcmi_enum_input,
+       .vidioc_g_input                 = dcmi_g_input,
+       .vidioc_s_input                 = dcmi_s_input,
+
+       .vidioc_enum_framesizes         = dcmi_enum_framesizes,
+       .vidioc_enum_frameintervals     = dcmi_enum_frameintervals,
+
+       .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
+       .vidioc_create_bufs             = vb2_ioctl_create_bufs,
+       .vidioc_querybuf                = vb2_ioctl_querybuf,
+       .vidioc_qbuf                    = vb2_ioctl_qbuf,
+       .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
+       .vidioc_expbuf                  = vb2_ioctl_expbuf,
+       .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
+       .vidioc_streamon                = vb2_ioctl_streamon,
+       .vidioc_streamoff               = vb2_ioctl_streamoff,
+
+       .vidioc_log_status              = v4l2_ctrl_log_status,
+       .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
+       .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
+};
+
+static const struct v4l2_file_operations dcmi_fops = {
+       .owner          = THIS_MODULE,
+       .unlocked_ioctl = video_ioctl2,
+       .open           = dcmi_open,
+       .release        = dcmi_release,
+       .poll           = vb2_fop_poll,
+       .mmap           = vb2_fop_mmap,
+#ifndef CONFIG_MMU
+       .get_unmapped_area = vb2_fop_get_unmapped_area,
+#endif
+       .read           = vb2_fop_read,
+};
+
+static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
+{
+       struct v4l2_format f = {
+               .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
+               .fmt.pix = {
+                       .width          = CIF_WIDTH,
+                       .height         = CIF_HEIGHT,
+                       .field          = V4L2_FIELD_NONE,
+                       .pixelformat    = dcmi->user_formats[0]->fourcc,
+               },
+       };
+       int ret;
+
+       ret = dcmi_try_fmt(dcmi, &f, NULL);
+       if (ret)
+               return ret;
+       dcmi->current_fmt = dcmi->user_formats[0];
+       dcmi->fmt = f;
+       return 0;
+}
+
+static const struct dcmi_format dcmi_formats[] = {
+       {
+               .fourcc = V4L2_PIX_FMT_RGB565,
+               .mbus_code = MEDIA_BUS_FMT_RGB565_2X8_LE,
+               .bpp = 2,
+       }, {
+               .fourcc = V4L2_PIX_FMT_YUYV,
+               .mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
+               .bpp = 2,
+       }, {
+               .fourcc = V4L2_PIX_FMT_UYVY,
+               .mbus_code = MEDIA_BUS_FMT_UYVY8_2X8,
+               .bpp = 2,
+       },
+};
+
+static int dcmi_formats_init(struct stm32_dcmi *dcmi)
+{
+       const struct dcmi_format *dcmi_fmts[ARRAY_SIZE(dcmi_formats)];
+       unsigned int num_fmts = 0, i, j;
+       struct v4l2_subdev *subdev = dcmi->entity.subdev;
+       struct v4l2_subdev_mbus_code_enum mbus_code = {
+               .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+       };
+
+       while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
+                                NULL, &mbus_code)) {
+               for (i = 0; i < ARRAY_SIZE(dcmi_formats); i++) {
+                       if (dcmi_formats[i].mbus_code != mbus_code.code)
+                               continue;
+
+                       /* Code supported, have we got this fourcc yet? */
+                       for (j = 0; j < num_fmts; j++)
+                               if (dcmi_fmts[j]->fourcc ==
+                                               dcmi_formats[i].fourcc)
+                                       /* Already available */
+                                       break;
+                       if (j == num_fmts)
+                               /* New */
+                               dcmi_fmts[num_fmts++] = dcmi_formats + i;
+               }
+               mbus_code.index++;
+       }
+
+       if (!num_fmts)
+               return -ENXIO;
+
+       dcmi->num_user_formats = num_fmts;
+       dcmi->user_formats = devm_kcalloc(dcmi->dev,
+                                        num_fmts, sizeof(struct dcmi_format *),
+                                        GFP_KERNEL);
+       if (!dcmi->user_formats) {
+               dev_err(dcmi->dev, "could not allocate memory\n");
+               return -ENOMEM;
+       }
+
+       memcpy(dcmi->user_formats, dcmi_fmts,
+              num_fmts * sizeof(struct dcmi_format *));
+       dcmi->current_fmt = dcmi->user_formats[0];
+
+       return 0;
+}
+
+static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier)
+{
+       struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
+       int ret;
+
+       dcmi->vdev->ctrl_handler        = dcmi->entity.subdev->ctrl_handler;
+       ret = dcmi_formats_init(dcmi);
+       if (ret) {
+               dev_err(dcmi->dev, "No supported mediabus format found\n");
+               return ret;
+       }
+
+       ret = dcmi_set_default_fmt(dcmi);
+       if (ret) {
+               dev_err(dcmi->dev, "Could not set default format\n");
+               return ret;
+       }
+
+       ret = video_register_device(dcmi->vdev, VFL_TYPE_GRABBER, -1);
+       if (ret) {
+               dev_err(dcmi->dev, "Failed to register video device\n");
+               return ret;
+       }
+
+       dev_dbg(dcmi->dev, "Device registered as %s\n",
+               video_device_node_name(dcmi->vdev));
+       return 0;
+}
+
+static void dcmi_graph_notify_unbind(struct v4l2_async_notifier *notifier,
+                                    struct v4l2_subdev *sd,
+                                    struct v4l2_async_subdev *asd)
+{
+       struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
+
+       dev_dbg(dcmi->dev, "Removing %s\n", video_device_node_name(dcmi->vdev));
+
+       /* Checks internaly if vdev has been init or not */
+       video_unregister_device(dcmi->vdev);
+}
+
+static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier,
+                                  struct v4l2_subdev *subdev,
+                                  struct v4l2_async_subdev *asd)
+{
+       struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
+
+       dev_dbg(dcmi->dev, "Subdev %s bound\n", subdev->name);
+
+       dcmi->entity.subdev = subdev;
+
+       return 0;
+}
+
+static int dcmi_graph_parse(struct stm32_dcmi *dcmi, struct device_node *node)
+{
+       struct device_node *ep = NULL;
+       struct device_node *remote;
+
+       while (1) {
+               ep = of_graph_get_next_endpoint(node, ep);
+               if (!ep)
+                       return -EINVAL;
+
+               remote = of_graph_get_remote_port_parent(ep);
+               if (!remote) {
+                       of_node_put(ep);
+                       return -EINVAL;
+               }
+
+               /* Remote node to connect */
+               dcmi->entity.node = remote;
+               dcmi->entity.asd.match_type = V4L2_ASYNC_MATCH_OF;
+               dcmi->entity.asd.match.of.node = remote;
+               return 0;
+       }
+}
+
+static int dcmi_graph_init(struct stm32_dcmi *dcmi)
+{
+       struct v4l2_async_subdev **subdevs = NULL;
+       int ret;
+
+       /* Parse the graph to extract a list of subdevice DT nodes. */
+       ret = dcmi_graph_parse(dcmi, dcmi->dev->of_node);
+       if (ret < 0) {
+               dev_err(dcmi->dev, "Graph parsing failed\n");
+               return ret;
+       }
+
+       /* Register the subdevices notifier. */
+       subdevs = devm_kzalloc(dcmi->dev, sizeof(*subdevs), GFP_KERNEL);
+       if (!subdevs) {
+               of_node_put(dcmi->entity.node);
+               return -ENOMEM;
+       }
+
+       subdevs[0] = &dcmi->entity.asd;
+
+       dcmi->notifier.subdevs = subdevs;
+       dcmi->notifier.num_subdevs = 1;
+       dcmi->notifier.bound = dcmi_graph_notify_bound;
+       dcmi->notifier.unbind = dcmi_graph_notify_unbind;
+       dcmi->notifier.complete = dcmi_graph_notify_complete;
+
+       ret = v4l2_async_notifier_register(&dcmi->v4l2_dev, &dcmi->notifier);
+       if (ret < 0) {
+               dev_err(dcmi->dev, "Notifier registration failed\n");
+               of_node_put(dcmi->entity.node);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int dcmi_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       const struct of_device_id *match = NULL;
+       struct v4l2_of_endpoint ep;
+       struct stm32_dcmi *dcmi;
+       struct vb2_queue *q;
+       struct dma_chan *chan;
+       struct clk *mclk;
+       int irq;
+       int ret;
+
+       match = of_match_device(of_match_ptr(stm32_dcmi_of_match), &pdev->dev);
+       if (!match) {
+               dev_err(&pdev->dev, "Could not find a match in devicetree\n");
+               return -ENODEV;
+       }
+
+       dcmi = devm_kzalloc(&pdev->dev, sizeof(struct stm32_dcmi), GFP_KERNEL);
+       if (!dcmi)
+               return -ENOMEM;
+
+       dcmi->rstc = of_reset_control_get(np, NULL);
+       if (IS_ERR(dcmi->rstc)) {
+               dev_err(&pdev->dev, "Could not get reset control\n");
+               return -ENODEV;
+       }
+
+       /* Get bus characteristics from devicetree */
+       np = of_graph_get_next_endpoint(np, NULL);
+       if (!np) {
+               dev_err(&pdev->dev, "Could not find the endpoint\n");
+               of_node_put(np);
+               goto err_reset_control_put;
+       }
+
+       ret = v4l2_of_parse_endpoint(np, &ep);
+       if (ret) {
+               dev_err(&pdev->dev, "Could not parse the endpoint\n");
+               of_node_put(np);
+               goto err_reset_control_put;
+       }
+
+       if (ep.bus_type == V4L2_MBUS_CSI2) {
+               dev_err(&pdev->dev, "CSI bus not supported\n");
+               of_node_put(np);
+               goto err_reset_control_put;
+       }
+       dcmi->bus.flags = ep.bus.parallel.flags;
+       dcmi->bus.bus_width = ep.bus.parallel.bus_width;
+       dcmi->bus.data_shift = ep.bus.parallel.data_shift;
+
+       of_node_put(np);
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq <= 0) {
+               dev_err(&pdev->dev, "Could not get irq\n");
+               return -ENODEV;
+       }
+
+       dcmi->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!dcmi->res) {
+               dev_err(&pdev->dev, "Could not get resource\n");
+               return -ENODEV;
+       }
+
+       dcmi->regs = devm_ioremap_resource(&pdev->dev, dcmi->res);
+       if (IS_ERR(dcmi->regs)) {
+               dev_err(&pdev->dev, "Could not map registers\n");
+               return PTR_ERR(dcmi->regs);
+       }
+
+       ret = devm_request_threaded_irq(&pdev->dev, irq, dcmi_irq_callback,
+                                       dcmi_irq_thread, IRQF_ONESHOT,
+                                       dev_name(&pdev->dev), dcmi);
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to request irq %d\n", irq);
+               return -ENODEV;
+       }
+
+       mclk = devm_clk_get(&pdev->dev, "mclk");
+       if (IS_ERR(mclk)) {
+               dev_err(&pdev->dev, "Unable to get mclk\n");
+               return PTR_ERR(mclk);
+       }
+
+       chan = dma_request_slave_channel(&pdev->dev, "tx");
+       if (!chan) {
+               dev_info(&pdev->dev, "Unable to request DMA channel, defer 
probing\n");
+               return -EPROBE_DEFER;
+       }
+
+       ret = clk_prepare(mclk);
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to prepare mclk %p\n", mclk);
+               goto err_dma_release;
+       }
+
+       spin_lock_init(&dcmi->irqlock);
+       mutex_init(&dcmi->lock);
+       init_completion(&dcmi->complete);
+       INIT_LIST_HEAD(&dcmi->buffers);
+
+       dcmi->dev = &pdev->dev;
+       dcmi->mclk = mclk;
+       dcmi->state = STOPPED;
+       dcmi->dma_chan = chan;
+
+       q = &dcmi->queue;
+
+       /* Initialize the top-level structure */
+       ret = v4l2_device_register(&pdev->dev, &dcmi->v4l2_dev);
+       if (ret)
+               goto err_clk_unprepare;
+
+       dcmi->vdev = video_device_alloc();
+       if (!dcmi->vdev) {
+               ret = -ENOMEM;
+               goto err_device_unregister;
+       }
+
+       /* Video node */
+       dcmi->vdev->fops = &dcmi_fops;
+       dcmi->vdev->v4l2_dev = &dcmi->v4l2_dev;
+       dcmi->vdev->queue = &dcmi->queue;
+       strlcpy(dcmi->vdev->name, KBUILD_MODNAME, sizeof(dcmi->vdev->name));
+       dcmi->vdev->release = video_device_release;
+       dcmi->vdev->ioctl_ops = &dcmi_ioctl_ops;
+       dcmi->vdev->lock = &dcmi->lock;
+       dcmi->vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
+                                 V4L2_CAP_READWRITE;
+       video_set_drvdata(dcmi->vdev, dcmi);
+
+       /* Buffer queue */
+       q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+       q->io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF;
+       q->lock = &dcmi->lock;
+       q->drv_priv = dcmi;
+       q->buf_struct_size = sizeof(struct dcmi_buf);
+       q->ops = &dcmi_video_qops;
+       q->mem_ops = &vb2_dma_contig_memops;
+       q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+       q->min_buffers_needed = 2;
+       q->dev = &pdev->dev;
+
+       ret = vb2_queue_init(q);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "Failed to initialize vb2 queue\n");
+               goto err_device_release;
+       }
+
+       ret = dcmi_graph_init(dcmi);
+       if (ret < 0)
+               goto err_device_release;
+
+       /* Reset device */
+       ret = reset_control_assert(dcmi->rstc);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to assert the reset line\n");
+               goto err_device_release;
+       }
+
+       usleep_range(3000, 5000);
+
+       ret = reset_control_deassert(dcmi->rstc);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to deassert the reset line\n");
+               goto err_device_release;
+       }
+
+       dev_info(&pdev->dev, "Probe done\n");
+
+       platform_set_drvdata(pdev, dcmi);
+       return 0;
+
+err_reset_control_put:
+       reset_control_put(dcmi->rstc);
+err_device_release:
+       video_device_release(dcmi->vdev);
+err_device_unregister:
+       v4l2_device_unregister(&dcmi->v4l2_dev);
+err_clk_unprepare:
+       clk_unprepare(dcmi->mclk);
+err_dma_release:
+       dma_release_channel(dcmi->dma_chan);
+
+       return ret;
+}
+
+static int dcmi_remove(struct platform_device *pdev)
+{
+       struct stm32_dcmi *dcmi = platform_get_drvdata(pdev);
+
+       v4l2_async_notifier_unregister(&dcmi->notifier);
+       v4l2_device_unregister(&dcmi->v4l2_dev);
+       clk_unprepare(dcmi->mclk);
+       dma_release_channel(dcmi->dma_chan);
+       reset_control_put(dcmi->rstc);
+
+       return 0;
+}
+
+static struct platform_driver stm32_dcmi_driver = {
+       .probe          = dcmi_probe,
+       .remove         = dcmi_remove,
+       .driver         = {
+               .name = DRV_NAME,
+               .of_match_table = of_match_ptr(stm32_dcmi_of_match),
+       },
+};
+
+module_platform_driver(stm32_dcmi_driver);
+
+MODULE_AUTHOR("Yannick Fertre <yannick.fer...@st.com>");
+MODULE_AUTHOR("Hugues Fruchet <hugues.fruc...@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Digital Camera Memory Interface 
driver");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("video");
-- 
1.9.1

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