V4L/DVB (11350): Add camera (CSI) driver for MX1

Add support for CMOS Sensor Interface on i.MX1 and i.MXL SoCs.

 create mode 100644 arch/arm/mach-mx1/ksym_mx1.c
 create mode 100644 arch/arm/mach-mx1/mx1_camera_fiq.S
 create mode 100644 arch/arm/plat-mxc/include/mach/mx1_camera.h
 create mode 100644 drivers/media/video/mx1_camera.c

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
Signed-off-by: Darius Augulis <augulis.darius@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 840 insertions, 1 deletions

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 76bad5819592..159229fc838d 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -746,6 +746,18 @@ config SOC_CAMERA_OV772X
         help
           This is a ov772x camera driver
 
+config MX1_VIDEO
+        bool
+
+config VIDEO_MX1
+        tristate "i.MX1/i.MXL CMOS Sensor Interface driver"
+        depends on VIDEO_DEV && ARCH_MX1 && SOC_CAMERA
+        select FIQ
+        select VIDEOBUF_DMA_CONTIG
+        select MX1_VIDEO
+        ---help---
+          This is a v4l2 driver for the i.MX1/i.MXL CMOS Sensor Interface
+
 config VIDEO_MX3
         tristate "i.MX3x Camera Sensor Interface driver"
         depends on VIDEO_DEV && MX3_IPU && SOC_CAMERA
@@ -904,5 +916,4 @@ config USB_S2255
           This driver can be compiled as a module, called s2255drv.
 
 endif # V4L_USB_DRIVERS
-
 endif # VIDEO_CAPTURE_DRIVERS
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index b9046744463b..ba02977adf10 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -133,6 +133,7 @@ obj-$(CONFIG_VIDEO_CX18) += cx18/
 obj-$(CONFIG_VIDEO_VIVI) += vivi.o
 obj-$(CONFIG_VIDEO_CX23885) += cx23885/
 
+obj-$(CONFIG_VIDEO_MX1)                 += mx1_camera.o
 obj-$(CONFIG_VIDEO_MX3)                 += mx3_camera.o
 obj-$(CONFIG_VIDEO_PXA27x)              += pxa_camera.o
 obj-$(CONFIG_VIDEO_SH_MOBILE_CEU)       += sh_mobile_ceu_camera.o
diff --git a/drivers/media/video/mx1_camera.c b/drivers/media/video/mx1_camera.c
new file mode 100644
index 000000000000..86fab56c5a20
--- /dev/null
+++ b/drivers/media/video/mx1_camera.c
@@ -0,0 +1,827 @@
+/*
+ * V4L2 Driver for i.MXL/i.MXL camera (CSI) host
+ *
+ * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ * Copyright (C) 2009, Darius Augulis <augulis.darius@gmail.com>
+ *
+ * Based on PXA SoC camera driver
+ * Copyright (C) 2006, Sascha Hauer, Pengutronix
+ * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/version.h>
+#include <linux/videodev2.h>
+
+#include <media/soc_camera.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-dev.h>
+#include <media/videobuf-dma-contig.h>
+
+#include <asm/dma.h>
+#include <asm/fiq.h>
+#include <mach/dma-mx1-mx2.h>
+#include <mach/hardware.h>
+#include <mach/mx1_camera.h>
+
+/*
+ * CSI registers
+ */
+#define DMA_CCR(x)      (0x8c + ((x) << 6))     /* Control Registers */
+#define DMA_DIMR        0x08                    /* Interrupt mask Register */
+#define CSICR1          0x00                    /* CSI Control Register 1 */
+#define CSISR           0x08                    /* CSI Status Register */
+#define CSIRXR          0x10                    /* CSI RxFIFO Register */
+
+#define CSICR1_RXFF_LEVEL(x)    (((x) & 0x3) << 19)
+#define CSICR1_SOF_POL          (1 << 17)
+#define CSICR1_SOF_INTEN        (1 << 16)
+#define CSICR1_MCLKDIV(x)       (((x) & 0xf) << 12)
+#define CSICR1_MCLKEN           (1 << 9)
+#define CSICR1_FCC              (1 << 8)
+#define CSICR1_BIG_ENDIAN       (1 << 7)
+#define CSICR1_CLR_RXFIFO       (1 << 5)
+#define CSICR1_GCLK_MODE        (1 << 4)
+#define CSICR1_DATA_POL         (1 << 2)
+#define CSICR1_REDGE            (1 << 1)
+#define CSICR1_EN               (1 << 0)
+
+#define CSISR_SFF_OR_INT        (1 << 25)
+#define CSISR_RFF_OR_INT        (1 << 24)
+#define CSISR_STATFF_INT        (1 << 21)
+#define CSISR_RXFF_INT          (1 << 18)
+#define CSISR_SOF_INT           (1 << 16)
+#define CSISR_DRDY              (1 << 0)
+
+#define VERSION_CODE KERNEL_VERSION(0, 0, 1)
+#define DRIVER_NAME "mx1-camera"
+
+#define CSI_IRQ_MASK    (CSISR_SFF_OR_INT | CSISR_RFF_OR_INT | \
+                        CSISR_STATFF_INT | CSISR_RXFF_INT | CSISR_SOF_INT)
+
+#define CSI_BUS_FLAGS   (SOCAM_MASTER | SOCAM_HSYNC_ACTIVE_HIGH | \
+                        SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_VSYNC_ACTIVE_LOW | \
+                        SOCAM_PCLK_SAMPLE_RISING | SOCAM_PCLK_SAMPLE_FALLING | \
+                        SOCAM_DATA_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_LOW | \
+                        SOCAM_DATAWIDTH_8)
+
+#define MAX_VIDEO_MEM 16        /* Video memory limit in megabytes */
+
+/*
+ * Structures
+ */
+
+/* buffer for one video frame */
+struct mx1_buffer {
+        /* common v4l buffer stuff -- must be first */
+        struct videobuf_buffer vb;
+        const struct soc_camera_data_format *fmt;
+        int inwork;
+};
+
+/* i.MX1/i.MXL is only supposed to handle one camera on its Camera Sensor
+ * Interface. If anyone ever builds hardware to enable more than
+ * one camera, they will have to modify this driver too */
+struct mx1_camera_dev {
+        struct soc_camera_device        *icd;
+        struct mx1_camera_pdata         *pdata;
+        struct mx1_buffer               *active;
+        struct device                   *dev;
+        struct resource                 *res;
+        struct clk                      *clk;
+        struct list_head                capture;
+
+        void __iomem                    *base;
+        int                             dma_chan;
+        unsigned int                    irq;
+        unsigned long                   mclk;
+
+        spinlock_t                      lock;
+};
+
+/*
+ *  Videobuf operations
+ */
+static int mx1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
+                              unsigned int *size)
+{
+        struct soc_camera_device *icd = vq->priv_data;
+
+        *size = icd->width * icd->height *
+                ((icd->current_fmt->depth + 7) >> 3);
+
+        if (!*count)
+                *count = 32;
+
+        while (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
+                (*count)--;
+
+        dev_dbg(&icd->dev, "count=%d, size=%d\n", *count, *size);
+
+        return 0;
+}
+
+static void free_buffer(struct videobuf_queue *vq, struct mx1_buffer *buf)
+{
+        struct soc_camera_device *icd = vq->priv_data;
+        struct videobuf_buffer *vb = &buf->vb;
+
+        BUG_ON(in_interrupt());
+
+        dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
+                vb, vb->baddr, vb->bsize);
+
+        /* This waits until this buffer is out of danger, i.e., until it is no
+         * longer in STATE_QUEUED or STATE_ACTIVE */
+        videobuf_waiton(vb, 0, 0);
+        videobuf_dma_contig_free(vq, vb);
+
+        vb->state = VIDEOBUF_NEEDS_INIT;
+}
+
+static int mx1_videobuf_prepare(struct videobuf_queue *vq,
+                struct videobuf_buffer *vb, enum v4l2_field field)
+{
+        struct soc_camera_device *icd = vq->priv_data;
+        struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
+        int ret;
+
+        dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
+                vb, vb->baddr, vb->bsize);
+
+        /* Added list head initialization on alloc */
+        WARN_ON(!list_empty(&vb->queue));
+
+        BUG_ON(NULL == icd->current_fmt);
+
+        /* I think, in buf_prepare you only have to protect global data,
+         * the actual buffer is yours */
+        buf->inwork = 1;
+
+        if (buf->fmt    != icd->current_fmt ||
+            vb->width   != icd->width ||
+            vb->height  != icd->height ||
+            vb->field   != field) {
+                buf->fmt        = icd->current_fmt;
+                vb->width       = icd->width;
+                vb->height      = icd->height;
+                vb->field       = field;
+                vb->state       = VIDEOBUF_NEEDS_INIT;
+        }
+
+        vb->size = vb->width * vb->height * ((buf->fmt->depth + 7) >> 3);
+        if (0 != vb->baddr && vb->bsize < vb->size) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        if (vb->state == VIDEOBUF_NEEDS_INIT) {
+                ret = videobuf_iolock(vq, vb, NULL);
+                if (ret)
+                        goto fail;
+
+                vb->state = VIDEOBUF_PREPARED;
+        }
+
+        buf->inwork = 0;
+
+        return 0;
+
+fail:
+        free_buffer(vq, buf);
+out:
+        buf->inwork = 0;
+        return ret;
+}
+
+static int mx1_camera_setup_dma(struct mx1_camera_dev *pcdev)
+{
+        struct videobuf_buffer *vbuf = &pcdev->active->vb;
+        int ret;
+
+        if (unlikely(!pcdev->active)) {
+                dev_err(pcdev->dev, "DMA End IRQ with no active buffer\n");
+                return -EFAULT;
+        }
+
+        /* setup sg list for future DMA */
+        ret = imx_dma_setup_single(pcdev->dma_chan,
+                videobuf_to_dma_contig(vbuf),
+                vbuf->size, pcdev->res->start +
+                CSIRXR, DMA_MODE_READ);
+        if (unlikely(ret))
+                dev_err(pcdev->dev, "Failed to setup DMA sg list\n");
+
+        return ret;
+}
+
+static void mx1_videobuf_queue(struct videobuf_queue *vq,
+                                                struct videobuf_buffer *vb)
+{
+        struct soc_camera_device *icd = vq->priv_data;
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        struct mx1_camera_dev *pcdev = ici->priv;
+        struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
+        unsigned long flags;
+
+        dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
+                vb, vb->baddr, vb->bsize);
+
+        spin_lock_irqsave(&pcdev->lock, flags);
+
+        list_add_tail(&vb->queue, &pcdev->capture);
+
+        vb->state = VIDEOBUF_ACTIVE;
+
+        if (!pcdev->active) {
+                pcdev->active = buf;
+
+                /* setup sg list for future DMA */
+                if (!mx1_camera_setup_dma(pcdev)) {
+                        unsigned int temp;
+                        /* enable SOF irq */
+                        temp = __raw_readl(pcdev->base + CSICR1) |
+                                                        CSICR1_SOF_INTEN;
+                        __raw_writel(temp, pcdev->base + CSICR1);
+                }
+        }
+
+        spin_unlock_irqrestore(&pcdev->lock, flags);
+}
+
+static void mx1_videobuf_release(struct videobuf_queue *vq,
+                                 struct videobuf_buffer *vb)
+{
+        struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
+#ifdef DEBUG
+        struct soc_camera_device *icd = vq->priv_data;
+
+        dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
+                vb, vb->baddr, vb->bsize);
+
+        switch (vb->state) {
+        case VIDEOBUF_ACTIVE:
+                dev_dbg(&icd->dev, "%s (active)\n", __func__);
+                break;
+        case VIDEOBUF_QUEUED:
+                dev_dbg(&icd->dev, "%s (queued)\n", __func__);
+                break;
+        case VIDEOBUF_PREPARED:
+                dev_dbg(&icd->dev, "%s (prepared)\n", __func__);
+                break;
+        default:
+                dev_dbg(&icd->dev, "%s (unknown)\n", __func__);
+                break;
+        }
+#endif
+
+        free_buffer(vq, buf);
+}
+
+static void mx1_camera_wakeup(struct mx1_camera_dev *pcdev,
+                              struct videobuf_buffer *vb,
+                              struct mx1_buffer *buf)
+{
+        /* _init is used to debug races, see comment in mx1_camera_reqbufs() */
+        list_del_init(&vb->queue);
+        vb->state = VIDEOBUF_DONE;
+        do_gettimeofday(&vb->ts);
+        vb->field_count++;
+        wake_up(&vb->done);
+
+        if (list_empty(&pcdev->capture)) {
+                pcdev->active = NULL;
+                return;
+        }
+
+        pcdev->active = list_entry(pcdev->capture.next,
+                                   struct mx1_buffer, vb.queue);
+
+        /* setup sg list for future DMA */
+        if (likely(!mx1_camera_setup_dma(pcdev))) {
+                unsigned int temp;
+
+                /* enable SOF irq */
+                temp = __raw_readl(pcdev->base + CSICR1) | CSICR1_SOF_INTEN;
+                __raw_writel(temp, pcdev->base + CSICR1);
+        }
+}
+
+static void mx1_camera_dma_irq(int channel, void *data)
+{
+        struct mx1_camera_dev *pcdev = data;
+        struct mx1_buffer *buf;
+        struct videobuf_buffer *vb;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pcdev->lock, flags);
+
+        imx_dma_disable(channel);
+
+        if (unlikely(!pcdev->active)) {
+                dev_err(pcdev->dev, "DMA End IRQ with no active buffer\n");
+                goto out;
+        }
+
+        vb = &pcdev->active->vb;
+        buf = container_of(vb, struct mx1_buffer, vb);
+        WARN_ON(buf->inwork || list_empty(&vb->queue));
+        dev_dbg(pcdev->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
+                vb, vb->baddr, vb->bsize);
+
+        mx1_camera_wakeup(pcdev, vb, buf);
+out:
+        spin_unlock_irqrestore(&pcdev->lock, flags);
+}
+
+static struct videobuf_queue_ops mx1_videobuf_ops = {
+        .buf_setup      = mx1_videobuf_setup,
+        .buf_prepare    = mx1_videobuf_prepare,
+        .buf_queue      = mx1_videobuf_queue,
+        .buf_release    = mx1_videobuf_release,
+};
+
+static void mx1_camera_init_videobuf(struct videobuf_queue *q,
+                                     struct soc_camera_device *icd)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        struct mx1_camera_dev *pcdev = ici->priv;
+
+        videobuf_queue_dma_contig_init(q, &mx1_videobuf_ops, pcdev->dev,
+                                        &pcdev->lock,
+                                        V4L2_BUF_TYPE_VIDEO_CAPTURE,
+                                        V4L2_FIELD_NONE,
+                                        sizeof(struct mx1_buffer), icd);
+}
+
+static int mclk_get_divisor(struct mx1_camera_dev *pcdev)
+{
+        unsigned int mclk = pcdev->mclk;
+        unsigned long div;
+        unsigned long lcdclk;
+
+        lcdclk = clk_get_rate(pcdev->clk);
+
+        /* We verify platform_mclk_10khz != 0, so if anyone breaks it, here
+         * they get a nice Oops */
+        div = (lcdclk + 2 * mclk - 1) / (2 * mclk) - 1;
+
+        dev_dbg(pcdev->dev, "System clock %lukHz, target freq %dkHz, "
+                "divisor %lu\n", lcdclk / 1000, mclk / 1000, div);
+
+        return div;
+}
+
+static void mx1_camera_activate(struct mx1_camera_dev *pcdev)
+{
+        unsigned int csicr1 = CSICR1_EN;
+
+        dev_dbg(pcdev->dev, "Activate device\n");
+
+        clk_enable(pcdev->clk);
+
+        /* enable CSI before doing anything else */
+        __raw_writel(csicr1, pcdev->base + CSICR1);
+
+        csicr1 |= CSICR1_MCLKEN | CSICR1_FCC | CSICR1_GCLK_MODE;
+        csicr1 |= CSICR1_MCLKDIV(mclk_get_divisor(pcdev));
+        csicr1 |= CSICR1_RXFF_LEVEL(2); /* 16 words */
+
+        __raw_writel(csicr1, pcdev->base + CSICR1);
+}
+
+static void mx1_camera_deactivate(struct mx1_camera_dev *pcdev)
+{
+        dev_dbg(pcdev->dev, "Deactivate device\n");
+
+        /* Disable all CSI interface */
+        __raw_writel(0x00, pcdev->base + CSICR1);
+
+        clk_disable(pcdev->clk);
+}
+
+/* The following two functions absolutely depend on the fact, that
+ * there can be only one camera on i.MX1/i.MXL camera sensor interface */
+static int mx1_camera_add_device(struct soc_camera_device *icd)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        struct mx1_camera_dev *pcdev = ici->priv;
+        int ret;
+
+        if (pcdev->icd) {
+                ret = -EBUSY;
+                goto ebusy;
+        }
+
+        dev_info(&icd->dev, "MX1 Camera driver attached to camera %d\n",
+                 icd->devnum);
+
+        mx1_camera_activate(pcdev);
+        ret = icd->ops->init(icd);
+
+        if (!ret)
+                pcdev->icd = icd;
+
+ebusy:
+        return ret;
+}
+
+static void mx1_camera_remove_device(struct soc_camera_device *icd)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        struct mx1_camera_dev *pcdev = ici->priv;
+        unsigned int csicr1;
+
+        BUG_ON(icd != pcdev->icd);
+
+        /* disable interrupts */
+        csicr1 = __raw_readl(pcdev->base + CSICR1) & ~CSI_IRQ_MASK;
+        __raw_writel(csicr1, pcdev->base + CSICR1);
+
+        /* Stop DMA engine */
+        imx_dma_disable(pcdev->dma_chan);
+
+        dev_info(&icd->dev, "MX1 Camera driver detached from camera %d\n",
+                 icd->devnum);
+
+        icd->ops->release(icd);
+
+        mx1_camera_deactivate(pcdev);
+
+        pcdev->icd = NULL;
+}
+
+static int mx1_camera_set_crop(struct soc_camera_device *icd,
+                               struct v4l2_rect *rect)
+{
+        return icd->ops->set_crop(icd, rect);
+}
+
+static int mx1_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        struct mx1_camera_dev *pcdev = ici->priv;
+        unsigned long camera_flags, common_flags;
+        unsigned int csicr1;
+        int ret;
+
+        camera_flags = icd->ops->query_bus_param(icd);
+
+        /* MX1 supports only 8bit buswidth */
+        common_flags = soc_camera_bus_param_compatible(camera_flags,
+                                                               CSI_BUS_FLAGS);
+        if (!common_flags)
+                return -EINVAL;
+
+        icd->buswidth = 8;
+
+        /* Make choises, based on platform choice */
+        if ((common_flags & SOCAM_VSYNC_ACTIVE_HIGH) &&
+                (common_flags & SOCAM_VSYNC_ACTIVE_LOW)) {
+                        if (!pcdev->pdata ||
+                             pcdev->pdata->flags & MX1_CAMERA_VSYNC_HIGH)
+                                common_flags &= ~SOCAM_VSYNC_ACTIVE_LOW;
+                        else
+                                common_flags &= ~SOCAM_VSYNC_ACTIVE_HIGH;
+        }
+
+        if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
+                (common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
+                        if (!pcdev->pdata ||
+                             pcdev->pdata->flags & MX1_CAMERA_PCLK_RISING)
+                                common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
+                        else
+                                common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
+        }
+
+        if ((common_flags & SOCAM_DATA_ACTIVE_HIGH) &&
+                (common_flags & SOCAM_DATA_ACTIVE_LOW)) {
+                        if (!pcdev->pdata ||
+                             pcdev->pdata->flags & MX1_CAMERA_DATA_HIGH)
+                                common_flags &= ~SOCAM_DATA_ACTIVE_LOW;
+                        else
+                                common_flags &= ~SOCAM_DATA_ACTIVE_HIGH;
+        }
+
+        ret = icd->ops->set_bus_param(icd, common_flags);
+        if (ret < 0)
+                return ret;
+
+        csicr1 = __raw_readl(pcdev->base + CSICR1);
+
+        if (common_flags & SOCAM_PCLK_SAMPLE_RISING)
+                csicr1 |= CSICR1_REDGE;
+        if (common_flags & SOCAM_VSYNC_ACTIVE_HIGH)
+                csicr1 |= CSICR1_SOF_POL;
+        if (common_flags & SOCAM_DATA_ACTIVE_LOW)
+                csicr1 |= CSICR1_DATA_POL;
+
+        __raw_writel(csicr1, pcdev->base + CSICR1);
+
+        return 0;
+}
+
+static int mx1_camera_set_fmt(struct soc_camera_device *icd,
+                              struct v4l2_format *f)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        const struct soc_camera_format_xlate *xlate;
+        struct v4l2_pix_format *pix = &f->fmt.pix;
+        int ret;
+
+        xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
+        if (!xlate) {
+                dev_warn(&ici->dev, "Format %x not found\n", pix->pixelformat);
+                return -EINVAL;
+        }
+
+        ret = icd->ops->set_fmt(icd, f);
+        if (!ret) {
+                icd->buswidth = xlate->buswidth;
+                icd->current_fmt = xlate->host_fmt;
+        }
+
+        return ret;
+}
+
+static int mx1_camera_try_fmt(struct soc_camera_device *icd,
+                              struct v4l2_format *f)
+{
+        /* TODO: limit to mx1 hardware capabilities */
+
+        /* limit to sensor capabilities */
+        return icd->ops->try_fmt(icd, f);
+}
+
+static int mx1_camera_reqbufs(struct soc_camera_file *icf,
+                              struct v4l2_requestbuffers *p)
+{
+        int i;
+
+        /* This is for locking debugging only. I removed spinlocks and now I
+         * check whether .prepare is ever called on a linked buffer, or whether
+         * a dma IRQ can occur for an in-work or unlinked buffer. Until now
+         * it hadn't triggered */
+        for (i = 0; i < p->count; i++) {
+                struct mx1_buffer *buf = container_of(icf->vb_vidq.bufs[i],
+                                                      struct mx1_buffer, vb);
+                buf->inwork = 0;
+                INIT_LIST_HEAD(&buf->vb.queue);
+        }
+
+        return 0;
+}
+
+static unsigned int mx1_camera_poll(struct file *file, poll_table *pt)
+{
+        struct soc_camera_file *icf = file->private_data;
+        struct mx1_buffer *buf;
+
+        buf = list_entry(icf->vb_vidq.stream.next, struct mx1_buffer,
+                         vb.stream);
+
+        poll_wait(file, &buf->vb.done, pt);
+
+        if (buf->vb.state == VIDEOBUF_DONE ||
+            buf->vb.state == VIDEOBUF_ERROR)
+                return POLLIN | POLLRDNORM;
+
+        return 0;
+}
+
+static int mx1_camera_querycap(struct soc_camera_host *ici,
+                               struct v4l2_capability *cap)
+{
+        /* cap->name is set by the friendly caller:-> */
+        strlcpy(cap->card, "i.MX1/i.MXL Camera", sizeof(cap->card));
+        cap->version = VERSION_CODE;
+        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+
+        return 0;
+}
+
+static struct soc_camera_host_ops mx1_soc_camera_host_ops = {
+        .owner          = THIS_MODULE,
+        .add            = mx1_camera_add_device,
+        .remove         = mx1_camera_remove_device,
+        .set_bus_param  = mx1_camera_set_bus_param,
+        .set_crop       = mx1_camera_set_crop,
+        .set_fmt        = mx1_camera_set_fmt,
+        .try_fmt        = mx1_camera_try_fmt,
+        .init_videobuf  = mx1_camera_init_videobuf,
+        .reqbufs        = mx1_camera_reqbufs,
+        .poll           = mx1_camera_poll,
+        .querycap       = mx1_camera_querycap,
+};
+
+/* Should be allocated dynamically too, but we have only one. */
+static struct soc_camera_host mx1_soc_camera_host = {
+        .drv_name       = DRIVER_NAME,
+        .ops            = &mx1_soc_camera_host_ops,
+};
+
+static struct fiq_handler fh = {
+        .name           = "csi_sof"
+};
+
+static int __init mx1_camera_probe(struct platform_device *pdev)
+{
+        struct mx1_camera_dev *pcdev;
+        struct resource *res;
+        struct pt_regs regs;
+        struct clk *clk;
+        void __iomem *base;
+        unsigned int irq;
+        int err = 0;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        irq = platform_get_irq(pdev, 0);
+        if (!res || !irq) {
+                err = -ENODEV;
+                goto exit;
+        }
+
+        clk = clk_get(&pdev->dev, "csi_clk");
+        if (IS_ERR(clk)) {
+                err = PTR_ERR(clk);
+                goto exit;
+        }
+
+        pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
+        if (!pcdev) {
+                dev_err(&pdev->dev, "Could not allocate pcdev\n");
+                err = -ENOMEM;
+                goto exit_put_clk;
+        }
+
+        dev_set_drvdata(&pdev->dev, pcdev);
+        pcdev->res = res;
+        pcdev->clk = clk;
+
+        pcdev->pdata = pdev->dev.platform_data;
+
+        if (pcdev->pdata)
+                pcdev->mclk = pcdev->pdata->mclk_10khz * 10000;
+
+        if (!pcdev->mclk) {
+                dev_warn(&pdev->dev,
+                         "mclk_10khz == 0! Please, fix your platform data. "
+                         "Using default 20MHz\n");
+                pcdev->mclk = 20000000;
+        }
+
+        INIT_LIST_HEAD(&pcdev->capture);
+        spin_lock_init(&pcdev->lock);
+
+        /*
+         * Request the regions.
+         */
+        if (!request_mem_region(res->start, resource_size(res), DRIVER_NAME)) {
+                err = -EBUSY;
+                goto exit_kfree;
+        }
+
+        base = ioremap(res->start, resource_size(res));
+        if (!base) {
+                err = -ENOMEM;
+                goto exit_release;
+        }
+        pcdev->irq = irq;
+        pcdev->base = base;
+        pcdev->dev = &pdev->dev;
+
+        /* request dma */
+        pcdev->dma_chan = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_HIGH);
+        if (pcdev->dma_chan < 0) {
+                dev_err(pcdev->dev, "Can't request DMA for MX1 CSI\n");
+                err = -EBUSY;
+                goto exit_iounmap;
+        }
+        dev_dbg(pcdev->dev, "got DMA channel %d\n", pcdev->dma_chan);
+
+        imx_dma_setup_handlers(pcdev->dma_chan, mx1_camera_dma_irq, NULL,
+                               pcdev);
+
+        imx_dma_config_channel(pcdev->dma_chan, IMX_DMA_TYPE_FIFO,
+                               IMX_DMA_MEMSIZE_32, DMA_REQ_CSI_R, 0);
+        /* burst length : 16 words = 64 bytes */
+        imx_dma_config_burstlen(pcdev->dma_chan, 0);
+
+        /* request irq */
+        err = claim_fiq(&fh);
+        if (err) {
+                dev_err(pcdev->dev, "Camera interrupt register failed \n");
+                goto exit_free_dma;
+        }
+
+        set_fiq_handler(&mx1_camera_sof_fiq_start, &mx1_camera_sof_fiq_end -
+                                                   &mx1_camera_sof_fiq_start);
+
+        regs.ARM_r8 = DMA_BASE + DMA_DIMR;
+        regs.ARM_r9 = DMA_BASE + DMA_CCR(pcdev->dma_chan);
+        regs.ARM_r10 = (long)pcdev->base + CSICR1;
+        regs.ARM_fp = (long)pcdev->base + CSISR;
+        regs.ARM_sp = 1 << pcdev->dma_chan;
+        set_fiq_regs(&regs);
+
+        mxc_set_irq_fiq(irq, 1);
+        enable_fiq(irq);
+
+        mx1_soc_camera_host.priv        = pcdev;
+        mx1_soc_camera_host.dev.parent  = &pdev->dev;
+        mx1_soc_camera_host.nr          = pdev->id;
+        err = soc_camera_host_register(&mx1_soc_camera_host);
+        if (err)
+                goto exit_free_irq;
+
+        dev_info(&pdev->dev, "MX1 Camera driver loaded\n");
+
+        return 0;
+
+exit_free_irq:
+        disable_fiq(irq);
+        mxc_set_irq_fiq(irq, 0);
+        release_fiq(&fh);
+exit_free_dma:
+        imx_dma_free(pcdev->dma_chan);
+exit_iounmap:
+        iounmap(base);
+exit_release:
+        release_mem_region(res->start, resource_size(res));
+exit_kfree:
+        kfree(pcdev);
+exit_put_clk:
+        clk_put(clk);
+exit:
+        return err;
+}
+
+static int __exit mx1_camera_remove(struct platform_device *pdev)
+{
+        struct mx1_camera_dev *pcdev = platform_get_drvdata(pdev);
+        struct resource *res;
+
+        imx_dma_free(pcdev->dma_chan);
+        disable_fiq(pcdev->irq);
+        mxc_set_irq_fiq(pcdev->irq, 0);
+        release_fiq(&fh);
+
+        clk_put(pcdev->clk);
+
+        soc_camera_host_unregister(&mx1_soc_camera_host);
+
+        iounmap(pcdev->base);
+
+        res = pcdev->res;
+        release_mem_region(res->start, resource_size(res));
+
+        kfree(pcdev);
+
+        dev_info(&pdev->dev, "MX1 Camera driver unloaded\n");
+
+        return 0;
+}
+
+static struct platform_driver mx1_camera_driver = {
+        .driver         = {
+                .name   = DRIVER_NAME,
+        },
+        .remove         = __exit_p(mx1_camera_remove),
+};
+
+static int __init mx1_camera_init(void)
+{
+        return platform_driver_probe(&mx1_camera_driver, mx1_camera_probe);
+}
+
+static void __exit mx1_camera_exit(void)
+{
+        return platform_driver_unregister(&mx1_camera_driver);
+}
+
+module_init(mx1_camera_init);
+module_exit(mx1_camera_exit);
+
+MODULE_DESCRIPTION("i.MX1/i.MXL SoC Camera Host driver");
+MODULE_AUTHOR("Paulius Zaleckas <paulius.zaleckas@teltonika.lt>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);