[PATCH v2 1/3] mx2_camera: Add soc_camera support for i.MX25/i.MX27

Guennadi Liakhovetski g.liakhovetski at gmx.de
Tue May 25 11:34:52 EDT 2010


On Mon, 24 May 2010, Baruch Siach wrote:

> This is the soc_camera support developed by Sascha Hauer for the i.MX27.  Alan
> Carvalho de Assis modified the original driver to get it working on more recent
> kernels. I modified it further to add support for i.MX25. This driver has been
> tested on i.MX25 and i.MX27 based platforms.
> 
> Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> ---
>  arch/arm/plat-mxc/include/mach/memory.h  |    4 +-
>  arch/arm/plat-mxc/include/mach/mx2_cam.h |   46 +
>  drivers/media/video/Kconfig              |   13 +
>  drivers/media/video/Makefile             |    1 +
>  drivers/media/video/mx2_camera.c         | 1471 ++++++++++++++++++++++++++++++
>  5 files changed, 1533 insertions(+), 2 deletions(-)
>  create mode 100644 arch/arm/plat-mxc/include/mach/mx2_cam.h
>  create mode 100644 drivers/media/video/mx2_camera.c
> 
> diff --git a/arch/arm/plat-mxc/include/mach/memory.h b/arch/arm/plat-mxc/include/mach/memory.h
> index c4b40c3..5803836 100644
> --- a/arch/arm/plat-mxc/include/mach/memory.h
> +++ b/arch/arm/plat-mxc/include/mach/memory.h
> @@ -44,12 +44,12 @@
>   */
>  #define CONSISTENT_DMA_SIZE SZ_8M
>  
> -#elif defined(CONFIG_MX1_VIDEO)
> +#elif defined(CONFIG_MX1_VIDEO) || defined(CONFIG_MX2_VIDEO)
>  /*
>   * Increase size of DMA-consistent memory region.
>   * This is required for i.MX camera driver to capture at least four VGA frames.
>   */
>  #define CONSISTENT_DMA_SIZE SZ_4M
> -#endif /* CONFIG_MX1_VIDEO */
> +#endif /* CONFIG_MX1_VIDEO || CONFIG_MX2_VIDEO */
>  
>  #endif /* __ASM_ARCH_MXC_MEMORY_H__ */
> diff --git a/arch/arm/plat-mxc/include/mach/mx2_cam.h b/arch/arm/plat-mxc/include/mach/mx2_cam.h
> new file mode 100644
> index 0000000..3c080a3
> --- /dev/null
> +++ b/arch/arm/plat-mxc/include/mach/mx2_cam.h
> @@ -0,0 +1,46 @@
> +/*
> + * mx2-cam.h - i.MX27/i.MX25 camera driver header file
> + *
> + * Copyright (C) 2003, Intel Corporation
> + * Copyright (C) 2008, Sascha Hauer <s.hauer at pengutronix.de>
> + * Copyright (C) 2010, Baruch Siach <baruch at tkos.co.il>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#ifndef __MACH_MX2_CAM_H_
> +#define __MACH_MX2_CAM_H_
> +
> +#define MX2_CAMERA_SWAP16		(1 << 0)
> +#define MX2_CAMERA_EXT_VSYNC		(1 << 1)
> +#define MX2_CAMERA_CCIR			(1 << 2)
> +#define MX2_CAMERA_CCIR_INTERLACE	(1 << 3)
> +#define MX2_CAMERA_HSYNC_HIGH		(1 << 4)
> +#define MX2_CAMERA_GATED_CLOCK		(1 << 5)
> +#define MX2_CAMERA_INV_DATA		(1 << 6)
> +#define MX2_CAMERA_PCLK_SAMPLE_RISING	(1 << 7)
> +#define MX2_CAMERA_PACK_DIR_MSB		(1 << 8)
> +
> +/**
> + * struct mx2_camera_platform_data - optional platform data for mx2_camera
> + * @flags: any combination of MX2_CAMERA_*
> + * @clk: clock rate of the csi block / 2
> + */
> +struct mx2_camera_platform_data {
> +	unsigned long flags;
> +	unsigned long clk;
> +};
> +
> +#endif /* __MACH_MX2_CAM_H_ */
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index 9644cf7..73b87a9 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -949,6 +949,19 @@ config VIDEO_OMAP2
>  	---help---
>  	  This is a v4l2 driver for the TI OMAP2 camera capture interface
>  
> +config MX2_VIDEO
> +        bool
> +
> +config VIDEO_MX2
> +	tristate "i.MX27/i.MX25 Camera Sensor Interface driver"
> +	depends on VIDEO_DEV && SOC_CAMERA && (MACH_MX27 || ARCH_MX25)
> +	select VIDEOBUF_DMA_CONTIG
> +	select MX2_VIDEO
> +	---help---
> +	  This is a v4l2 driver for the i.MX27 and the i.MX25 Camera Sensor
> +	  Interface
> +
> +
>  #
>  # USB Multimedia device configuration
>  #
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index c51c386..72615fd 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -156,6 +156,7 @@ obj-$(CONFIG_SOC_CAMERA)		+= soc_camera.o soc_mediabus.o
>  obj-$(CONFIG_SOC_CAMERA_PLATFORM)	+= soc_camera_platform.o
>  # soc-camera host drivers have to be linked after camera drivers
>  obj-$(CONFIG_VIDEO_MX1)			+= mx1_camera.o
> +obj-$(CONFIG_VIDEO_MX2)			+= mx2_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/mx2_camera.c b/drivers/media/video/mx2_camera.c
> new file mode 100644
> index 0000000..d0a3950
> --- /dev/null
> +++ b/drivers/media/video/mx2_camera.c
> @@ -0,0 +1,1471 @@
> +/*
> + * V4L2 Driver for i.MX27/i.MX25 camera host
> + *
> + * Copyright (C) 2008, Sascha Hauer, Pengutronix
> + * Copyright (C) 2010, Baruch Siach, Orex Computed Radiography
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/moduleparam.h>
> +#include <linux/time.h>
> +#include <linux/version.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/mutex.h>
> +#include <linux/clk.h>
> +
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-dev.h>
> +#include <media/videobuf-dma-contig.h>
> +#include <media/soc_camera.h>
> +#include <media/soc_mediabus.h>
> +
> +#include <linux/videodev2.h>
> +
> +#include <mach/mx2_cam.h>
> +#include <mach/dma-mx1-mx2.h>
> +#include <mach/hardware.h>
> +
> +#include <asm/dma.h>
> +
> +#define MX2_CAM_DRV_NAME "mx2-camera"
> +#define MX2_CAM_VERSION_CODE KERNEL_VERSION(0, 0, 5)
> +#define MX2_CAM_DRIVER_DESCRIPTION "i.MX2x_Camera"
> +
> +/* reset values */
> +#define CSICR1_RESET_VAL	0x40000800
> +#define CSICR2_RESET_VAL	0x0
> +#define CSICR3_RESET_VAL	0x0
> +
> +/* csi control reg 1 */
> +#define CSICR1_SWAP16_EN	(1 << 31)
> +#define CSICR1_EXT_VSYNC	(1 << 30)
> +#define CSICR1_EOF_INTEN	(1 << 29)
> +#define CSICR1_PRP_IF_EN	(1 << 28)
> +#define CSICR1_CCIR_MODE	(1 << 27)
> +#define CSICR1_COF_INTEN	(1 << 26)
> +#define CSICR1_SF_OR_INTEN	(1 << 25)
> +#define CSICR1_RF_OR_INTEN	(1 << 24)
> +#define CSICR1_STATFF_LEVEL	(3 << 22)
> +#define CSICR1_STATFF_INTEN	(1 << 21)
> +#define CSICR1_RXFF_LEVEL(l)	(((l) & 3) << 19)	/* MX27 */
> +#define CSICR1_FB2_DMA_INTEN	(1 << 20)		/* MX25 */
> +#define CSICR1_FB1_DMA_INTEN	(1 << 19)		/* MX25 */
> +#define CSICR1_RXFF_INTEN	(1 << 18)
> +#define CSICR1_SOF_POL		(1 << 17)
> +#define CSICR1_SOF_INTEN	(1 << 16)
> +#define CSICR1_MCLKDIV(d)	(((d) & 0xF) << 12)
> +#define CSICR1_HSYNC_POL	(1 << 11)
> +#define CSICR1_CCIR_EN		(1 << 10)
> +#define CSICR1_MCLKEN		(1 << 9)
> +#define CSICR1_FCC		(1 << 8)
> +#define CSICR1_PACK_DIR		(1 << 7)
> +#define CSICR1_CLR_STATFIFO	(1 << 6)
> +#define CSICR1_CLR_RXFIFO	(1 << 5)
> +#define CSICR1_GCLK_MODE	(1 << 4)
> +#define CSICR1_INV_DATA		(1 << 3)
> +#define CSICR1_INV_PCLK		(1 << 2)
> +#define CSICR1_REDGE		(1 << 1)
> +
> +#define SHIFT_STATFF_LEVEL	22
> +#define SHIFT_RXFF_LEVEL	19
> +#define SHIFT_MCLKDIV		12
> +
> +/* control reg 3 */
> +#define CSICR3_FRMCNT		(0xFFFF << 16)
> +#define CSICR3_FRMCNT_RST	(1 << 15)
> +#define CSICR3_DMA_REFLASH_RFF	(1 << 14)
> +#define CSICR3_DMA_REFLASH_SFF	(1 << 13)
> +#define CSICR3_DMA_REQ_EN_RFF	(1 << 12)
> +#define CSICR3_DMA_REQ_EN_SFF	(1 << 11)
> +#define CSICR3_RXFF_LEVEL(l)	(((l) & 7) << 4)	/* MX25 */
> +#define CSICR3_CSI_SUP		(1 << 3)
> +#define CSICR3_ZERO_PACK_EN	(1 << 2)
> +#define CSICR3_ECC_INT_EN	(1 << 1)
> +#define CSICR3_ECC_AUTO_EN	(1 << 0)
> +
> +#define SHIFT_FRMCNT		16
> +
> +/* csi status reg */
> +#define CSISR_SFF_OR_INT	(1 << 25)
> +#define CSISR_RFF_OR_INT	(1 << 24)
> +#define CSISR_STATFF_INT	(1 << 21)
> +#define CSISR_DMA_TSF_FB2_INT	(1 << 20)	/* MX25 */
> +#define CSISR_DMA_TSF_FB1_INT	(1 << 19)	/* MX25 */
> +#define CSISR_RXFF_INT		(1 << 18)
> +#define CSISR_EOF_INT		(1 << 17)
> +#define CSISR_SOF_INT		(1 << 16)
> +#define CSISR_F2_INT		(1 << 15)
> +#define CSISR_F1_INT		(1 << 14)
> +#define CSISR_COF_INT		(1 << 13)
> +#define CSISR_ECC_INT		(1 << 1)
> +#define CSISR_DRDY		(1 << 0)
> +
> +#define CSICR1			0x00
> +#define CSICR2			0x04
> +#define CSISR			(cpu_is_mx27() ? 0x08 : 0x18)
> +#define CSISTATFIFO		0x0c
> +#define CSIRFIFO		0x10
> +#define CSIRXCNT		0x14
> +#define CSICR3			(cpu_is_mx27() ? 0x1C : 0x08)
> +#define CSIDMASA_STATFIFO	0x20
> +#define CSIDMATA_STATFIFO	0x24
> +#define CSIDMASA_FB1		0x28
> +#define CSIDMASA_FB2		0x2c
> +#define CSIFBUF_PARA		0x30
> +#define CSIIMAG_PARA		0x34
> +
> +/* EMMA PrP */
> +#define PRP_CNTL			0x00
> +#define PRP_INTR_CNTL			0x04
> +#define PRP_INTRSTATUS			0x08
> +#define PRP_SOURCE_Y_PTR		0x0c
> +#define PRP_SOURCE_CB_PTR		0x10
> +#define PRP_SOURCE_CR_PTR		0x14
> +#define PRP_DEST_RGB1_PTR		0x18
> +#define PRP_DEST_RGB2_PTR		0x1c
> +#define PRP_DEST_Y_PTR			0x20
> +#define PRP_DEST_CB_PTR			0x24
> +#define PRP_DEST_CR_PTR			0x28
> +#define PRP_SRC_FRAME_SIZE		0x2c
> +#define PRP_DEST_CH1_LINE_STRIDE	0x30
> +#define PRP_SRC_PIXEL_FORMAT_CNTL	0x34
> +#define PRP_CH1_PIXEL_FORMAT_CNTL	0x38
> +#define PRP_CH1_OUT_IMAGE_SIZE		0x3c
> +#define PRP_CH2_OUT_IMAGE_SIZE		0x40
> +#define PRP_SRC_LINE_STRIDE		0x44
> +#define PRP_CSC_COEF_012		0x48
> +#define PRP_CSC_COEF_345		0x4c
> +#define PRP_CSC_COEF_678		0x50
> +#define PRP_CH1_RZ_HORI_COEF1		0x54
> +#define PRP_CH1_RZ_HORI_COEF2		0x58
> +#define PRP_CH1_RZ_HORI_VALID		0x5c
> +#define PRP_CH1_RZ_VERT_COEF1		0x60
> +#define PRP_CH1_RZ_VERT_COEF2		0x64
> +#define PRP_CH1_RZ_VERT_VALID		0x68
> +#define PRP_CH2_RZ_HORI_COEF1		0x6c
> +#define PRP_CH2_RZ_HORI_COEF2		0x70
> +#define PRP_CH2_RZ_HORI_VALID		0x74
> +#define PRP_CH2_RZ_VERT_COEF1		0x78
> +#define PRP_CH2_RZ_VERT_COEF2		0x7c
> +#define PRP_CH2_RZ_VERT_VALID		0x80
> +
> +#define PRP_CNTL_CH1EN		(1 << 0)
> +#define PRP_CNTL_CH2EN		(1 << 1)
> +#define PRP_CNTL_CSIEN		(1 << 2)
> +#define PRP_CNTL_DATA_IN_YUV420	(0 << 3)
> +#define PRP_CNTL_DATA_IN_YUV422	(1 << 3)
> +#define PRP_CNTL_DATA_IN_RGB16	(2 << 3)
> +#define PRP_CNTL_DATA_IN_RGB32	(3 << 3)
> +#define PRP_CNTL_CH1_OUT_RGB8	(0 << 5)
> +#define PRP_CNTL_CH1_OUT_RGB16	(1 << 5)
> +#define PRP_CNTL_CH1_OUT_RGB32	(2 << 5)
> +#define PRP_CNTL_CH1_OUT_YUV422	(3 << 5)
> +#define PRP_CNTL_CH2_OUT_YUV420	(0 << 7)
> +#define PRP_CNTL_CH2_OUT_YUV422 (1 << 7)
> +#define PRP_CNTL_CH2_OUT_YUV444	(2 << 7)
> +#define PRP_CNTL_CH1_LEN	(1 << 9)
> +#define PRP_CNTL_CH2_LEN	(1 << 10)
> +#define PRP_CNTL_SKIP_FRAME	(1 << 11)
> +#define PRP_CNTL_SWRST		(1 << 12)
> +#define PRP_CNTL_CLKEN		(1 << 13)
> +#define PRP_CNTL_WEN		(1 << 14)
> +#define PRP_CNTL_CH1BYP		(1 << 15)
> +#define PRP_CNTL_IN_TSKIP(x)	((x) << 16)
> +#define PRP_CNTL_CH1_TSKIP(x)	((x) << 19)
> +#define PRP_CNTL_CH2_TSKIP(x)	((x) << 22)
> +#define PRP_CNTL_INPUT_FIFO_LEVEL(x)	((x) << 25)
> +#define PRP_CNTL_RZ_FIFO_LEVEL(x)	((x) << 27)
> +#define PRP_CNTL_CH2B1EN	(1 << 29)
> +#define PRP_CNTL_CH2B2EN	(1 << 30)
> +#define PRP_CNTL_CH2FEN		(1 << 31)
> +
> +/* IRQ Enable and status register */
> +#define PRP_INTR_RDERR		(1 << 0)
> +#define PRP_INTR_CH1WERR	(1 << 1)
> +#define PRP_INTR_CH2WERR	(1 << 2)
> +#define PRP_INTR_CH1FC		(1 << 3)
> +#define PRP_INTR_CH2FC		(1 << 5)
> +#define PRP_INTR_LBOVF		(1 << 7)
> +#define PRP_INTR_CH2OVF		(1 << 8)
> +
> +#define mx27_camera_emma(pcdev)	(cpu_is_mx27() && pcdev->use_emma)
> +
> +#define MAX_VIDEO_MEM	16
> +
> +struct mx2_camera_dev {
> +	struct device		*dev;
> +	struct soc_camera_host	soc_host;
> +	struct soc_camera_device *icd;
> +	struct clk		*clk_csi, *clk_emma;
> +
> +	unsigned int		irq_csi, irq_emma;
> +	void __iomem		*base_csi, *base_emma;
> +	unsigned long		base_dma;
> +
> +	struct mx2_camera_platform_data *pdata;
> +	struct resource		*res_csi, *res_emma;
> +	unsigned long		platform_flags;
> +
> +	struct list_head	capture;
> +	struct list_head	active_bufs;
> +
> +	spinlock_t		lock;
> +
> +	int			dma;
> +	struct mx2_buffer	*active;
> +	struct mx2_buffer	*fb1_active;
> +	struct mx2_buffer	*fb2_active;
> +
> +	int			use_emma;
> +
> +	u32			csicr1;
> +
> +	void __iomem		*discard_buffer;
> +	dma_addr_t		discard_buffer_dma;
> +	size_t			discard_size;
> +};
> +
> +/* buffer for one video frame */
> +struct mx2_buffer {
> +	/* common v4l buffer stuff -- must be first */
> +	struct videobuf_buffer		vb;
> +
> +	enum v4l2_mbus_pixelcode	code;
> +
> +	int bufnum;
> +};
> +
> +static int mclk_get_divisor(struct mx2_camera_dev *pcdev)
> +{
> +	dev_info(pcdev->dev, "%s not implemented. Running at max speed\n",
> +			__func__);
> +

Ok, this will disappear.

> +#if 0
> +	unsigned int mclk = pcdev->pdata->clk_csi;
> +	unsigned int pclk = clk_get_rate(pcdev->clk_csi);
> +	int i;
> +
> +	dev_dbg(pcdev->dev, "%s: %ld %ld\n", __func__, mclk, pclk);
> +
> +	for (i = 0; i < 0xf; i++)
> +		if ((i + 1) * 2 * mclk <= pclk)
> +			break;

I know, you have it from the previous review, I'll just put it here again 
as a reminder for myself for the next time - verify, that this is gone, 
otherwise calculations are wrong.

> +	return i;
> +#endif
> +	return 0;
> +}
> +
> +static void mx2_camera_deactivate(struct mx2_camera_dev *pcdev)
> +{
> +	unsigned long flags;
> +
> +	clk_disable(pcdev->clk_csi);
> +	writel(0, pcdev->base_csi + CSICR1);
> +	if (mx27_camera_emma(pcdev))
> +		writel(0, pcdev->base_emma + PRP_CNTL);
> +	else if (cpu_is_mx25()) {

Missing braces in the "if" case.

> +		spin_lock_irqsave(&pcdev->lock, flags);
> +		pcdev->fb1_active = NULL;
> +		pcdev->fb2_active = NULL;
> +		writel(0, pcdev->base_csi + CSIDMASA_FB1);
> +		writel(0, pcdev->base_csi + CSIDMASA_FB2);
> +		spin_unlock_irqrestore(&pcdev->lock, flags);
> +	}
> +}
> +
> +/*
> + * The following two functions absolutely depend on the fact, that
> + * there can be only one camera on mx2 camera sensor interface
> + */
> +static int mx2_camera_add_device(struct soc_camera_device *icd)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct mx2_camera_dev *pcdev = ici->priv;
> +	int ret;
> +	u32 csicr1;
> +
> +	if (pcdev->icd)
> +		return -EBUSY;
> +
> +	ret = clk_enable(pcdev->clk_csi);
> +	if (ret < 0)
> +		return ret;
> +
> +	csicr1 = CSICR1_MCLKDIV(mclk_get_divisor(pcdev)) |
> +			CSICR1_MCLKEN;
> +
> +	if (mx27_camera_emma(pcdev)) {
> +		csicr1 |= CSICR1_PRP_IF_EN | CSICR1_FCC |
> +			CSICR1_RXFF_LEVEL(0);
> +	} else if (cpu_is_mx27())
> +		csicr1 |= CSICR1_SOF_INTEN | CSICR1_RXFF_LEVEL(2);
> +
> +	pcdev->csicr1 = csicr1;
> +	writel(pcdev->csicr1, pcdev->base_csi + CSICR1);
> +
> +	pcdev->icd = icd;
> +
> +	dev_info(icd->dev.parent, "Camera driver attached to camera %d\n",
> +		 icd->devnum);
> +
> +	return 0;
> +}
> +
> +static void mx2_camera_remove_device(struct soc_camera_device *icd)
> +{
> +	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
> +	struct mx2_camera_dev *pcdev = ici->priv;
> +
> +	BUG_ON(icd != pcdev->icd);
> +
> +	dev_info(icd->dev.parent, "Camera driver detached from camera %d\n",
> +		 icd->devnum);
> +
> +	mx2_camera_deactivate(pcdev);
> +
> +	if (pcdev->discard_buffer) {
> +		dma_free_coherent(ici->v4l2_dev.dev, pcdev->discard_size,
> +				pcdev->discard_buffer,
> +				pcdev->discard_buffer_dma);
> +		pcdev->discard_buffer = NULL;
> +	}
> +
> +	pcdev->icd = NULL;
> +}
> +
> +static void mx27_camera_dma_enable(struct mx2_camera_dev *pcdev)
> +{
> +	u32 tmp;
> +
> +	imx_dma_enable(pcdev->dma);
> +
> +	tmp = readl(pcdev->base_csi + CSICR1);
> +	tmp |= CSICR1_RF_OR_INTEN;
> +	writel(tmp, pcdev->base_csi + CSICR1);
> +}
> +
> +static irqreturn_t mx27_camera_irq(int irq_csi, void *data)
> +{
> +	struct mx2_camera_dev *pcdev = data;
> +	u32 status = readl(pcdev->base_csi + CSISR);
> +
> +	if (status & CSISR_SOF_INT && pcdev->active) {
> +		u32 tmp;
> +
> +		tmp = readl(pcdev->base_csi + CSICR1);
> +		writel(tmp | CSICR1_CLR_RXFIFO, pcdev->base_csi + CSICR1);
> +		mx27_camera_dma_enable(pcdev);
> +	}
> +
> +	writel(CSISR_SOF_INT | CSISR_RFF_OR_INT, pcdev->base_csi + CSISR);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void mx25_camera_frame_done(struct mx2_camera_dev *pcdev, int fb,
> +		int state)
> +{
> +	struct videobuf_buffer *vb;
> +	struct mx2_buffer *buf;
> +	struct mx2_buffer **fb_active = fb == 1 ? &pcdev->fb1_active :
> +		&pcdev->fb2_active;
> +	u32 fb_reg = fb == 1 ? CSIDMASA_FB1 : CSIDMASA_FB2;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +
> +	vb = &(*fb_active)->vb;
> +	dev_dbg(pcdev->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
> +		vb, vb->baddr, vb->bsize);
> +
> +	vb->state = state;
> +	do_gettimeofday(&vb->ts);
> +	vb->field_count++;
> +
> +	wake_up(&vb->done);
> +
> +	if (list_empty(&pcdev->capture)) {
> +		buf = NULL;
> +		writel(0, pcdev->base_csi + fb_reg);
> +	} else {
> +		buf = list_entry(pcdev->capture.next, struct mx2_buffer,
> +				vb.queue);
> +		vb = &buf->vb;
> +		list_del(&vb->queue);
> +		vb->state = VIDEOBUF_ACTIVE;
> +		writel(videobuf_to_dma_contig(vb), pcdev->base_csi + fb_reg);
> +	}
> +
> +	*fb_active = buf;
> +
> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +}
> +
> +static irqreturn_t mx25_camera_irq(int irq_csi, void *data)
> +{
> +	struct mx2_camera_dev *pcdev = data;
> +	u32 status = readl(pcdev->base_csi + CSISR);
> +
> +	if (status & CSISR_DMA_TSF_FB1_INT)
> +		mx25_camera_frame_done(pcdev, 1, VIDEOBUF_DONE);
> +	else if (status & CSISR_DMA_TSF_FB2_INT)
> +		mx25_camera_frame_done(pcdev, 2, VIDEOBUF_DONE);
> +
> +	/* FIXME: handle CSISR_RFF_OR_INT */
> +
> +	writel(status, pcdev->base_csi + CSISR);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*
> + *  Videobuf operations
> + */
> +static int mx2_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
> +			      unsigned int *size)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
> +			icd->current_fmt->host_fmt);
> +
> +	dev_dbg(&icd->dev, "count=%d, size=%d\n", *count, *size);
> +
> +	if (bytes_per_line < 0)
> +		return bytes_per_line;
> +
> +	*size = bytes_per_line * icd->user_height;
> +
> +	if (0 == *count)
> +		*count = 32;
> +	if (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
> +		*count = (MAX_VIDEO_MEM * 1024 * 1024) / *size;
> +
> +	return 0;
> +}
> +
> +static void free_buffer(struct videobuf_queue *vq, struct mx2_buffer *buf)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	struct videobuf_buffer *vb = &buf->vb;
> +
> +	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, 1);

No, you should be careful with this. You changed from uninterruptible wait 
to interruptible wait. In this case you have to check the return code and 
process the interrupted wait accordingly.

> +
> +	videobuf_dma_contig_free(vq, vb);
> +	dev_dbg(&icd->dev, "%s freed\n", __func__);
> +
> +	vb->state = VIDEOBUF_NEEDS_INIT;
> +}
> +
> +static int mx2_videobuf_prepare(struct videobuf_queue *vq,
> +		struct videobuf_buffer *vb, enum v4l2_field field)
> +{
> +	struct soc_camera_device *icd = vq->priv_data;
> +	struct mx2_buffer *buf = container_of(vb, struct mx2_buffer, vb);
> +	int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
> +			icd->current_fmt->host_fmt);
> +	int ret = 0;
> +
> +	dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
> +		vb, vb->baddr, vb->bsize);
> +
> +	if (bytes_per_line < 0)
> +		return bytes_per_line;
> +
> +#ifdef DEBUG
> +	/*
> +	 * This can be useful if you want to see if we actually fill
> +	 * the buffer with something
> +	 */
> +	memset((void *)vb->baddr, 0xaa, vb->bsize);
> +#endif
> +
> +	if (buf->code	!= icd->current_fmt->code ||
> +	    vb->width	!= icd->user_width ||
> +	    vb->height	!= icd->user_height ||
> +	    vb->field	!= field) {
> +		buf->code	= icd->current_fmt->code;
> +		vb->width	= icd->user_width;
> +		vb->height	= icd->user_height;
> +		vb->field	= field;
> +		vb->state	= VIDEOBUF_NEEDS_INIT;
> +	}
> +
> +	vb->size = bytes_per_line * vb->height;
> +	if (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;
> +	}
> +
> +	return 0;
> +
> +fail:
> +	free_buffer(vq, buf);
> +out:
> +	return ret;
> +}
> +
> +static void mx2_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 mx2_camera_dev *pcdev = ici->priv;
> +	struct mx2_buffer *buf = container_of(vb, struct mx2_buffer, vb);
> +	unsigned long flags;
> +	int ret;
> +
> +	dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
> +		vb, vb->baddr, vb->bsize);
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +
> +	vb->state = VIDEOBUF_QUEUED;
> +	list_add_tail(&vb->queue, &pcdev->capture);
> +
> +	if (mx27_camera_emma(pcdev))
> +		goto out;
> +	else if (cpu_is_mx27()) {
> +		if (pcdev->active != NULL) {

In v1 you had

> +		if (!pcdev->active) {

i.e., opposite logic. v2 seems to be wrong.

> +			ret = imx_dma_setup_single(pcdev->dma,
> +					videobuf_to_dma_contig(vb), vb->size,
> +					(u32)pcdev->base_dma + 0x10,
> +					DMA_MODE_READ);
> +			if (ret) {
> +				vb->state = VIDEOBUF_ERROR;
> +				wake_up(&vb->done);
> +				goto out;
> +			}
> +
> +			vb->state = VIDEOBUF_ACTIVE;

This is different from v1 of your patch. I meant not below this if, but 3 
lines down:

> +			pcdev->active = buf;
> +		}

...here. Otherwise, if you don't enter the "active == NULL" if, your state 
remains at "QUEUED." OTOH, maybe this is deliberate and you want to only 
set the buffer to "ACTIVE" if it's really becomming active?

> +	} else { /* cpu_is_mx25() */
> +		u32 csicr3, dma_inten = 0;
> +
> +		if (pcdev->fb1_active == NULL) {
> +			writel(videobuf_to_dma_contig(vb),
> +					pcdev->base_csi + CSIDMASA_FB1);
> +			pcdev->fb1_active = buf;
> +			dma_inten = CSICR1_FB1_DMA_INTEN;
> +		} else if (pcdev->fb2_active == NULL) {
> +			writel(videobuf_to_dma_contig(vb),
> +					pcdev->base_csi + CSIDMASA_FB2);
> +			pcdev->fb2_active = buf;
> +			dma_inten = CSICR1_FB2_DMA_INTEN;
> +		}
> +
> +		if (dma_inten) {
> +			list_del(&vb->queue);
> +			vb->state = VIDEOBUF_ACTIVE;
> +
> +			csicr3 = readl(pcdev->base_csi + CSICR3);
> +
> +			/* Reflash DMA */
> +			writel(csicr3 | CSICR3_DMA_REFLASH_RFF,
> +					pcdev->base_csi + CSICR3);
> +
> +			/* clear & enable interrupts */
> +			writel(dma_inten, pcdev->base_csi + CSISR);
> +			pcdev->csicr1 |= dma_inten;
> +			writel(pcdev->csicr1, pcdev->base_csi + CSICR1);
> +
> +			/* enable DMA */
> +			csicr3 |= CSICR3_DMA_REQ_EN_RFF | CSICR3_RXFF_LEVEL(1);
> +			writel(csicr3, pcdev->base_csi + CSICR3);
> +		}
> +	}
> +
> +out:
> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +}
> +
> +static void mx2_videobuf_release(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 mx2_camera_dev *pcdev = ici->priv;
> +	struct mx2_buffer *buf = container_of(vb, struct mx2_buffer, vb);
> +	unsigned long flags;
> +
> +#ifdef DEBUG
> +	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_info(&icd->dev, "%s (active)\n", __func__);
> +		break;
> +	case VIDEOBUF_QUEUED:
> +		dev_info(&icd->dev, "%s (queued)\n", __func__);
> +		break;
> +	case VIDEOBUF_PREPARED:
> +		dev_info(&icd->dev, "%s (prepared)\n", __func__);
> +		break;
> +	default:
> +		dev_info(&icd->dev, "%s (unknown) %d\n", __func__,
> +				vb->state);
> +		break;
> +	}
> +#endif
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +	if (cpu_is_mx25() && vb->state == VIDEOBUF_QUEUED) {
> +		list_del(&vb->queue);
> +		vb->state = VIDEOBUF_ERROR;
> +	}

This is something quite different from v1 and from what I suggested. Now 
you do not dequeue buffers in this function on mx27 at all?

In this function you can select one of the two approaches: either you 
terminate all buffers, including currently active ones, for which you 
also have to stop DMA, immediately and return them to the user with an 
error, or you wait for active buffers to complete naturally and only 
forcedly terminate queued but inactive buffers. The former is, probably, 
more like what the user expects and should complete immediately, whereas 
the latter can be easier to implement, but can put the user to sleep until 
the buffer is complete. But it either case it is, probably, better to be 
consistent across hardware types.

And then, given the error in the datasheet, all the more a comment will be 
required.

> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +
> +	free_buffer(vq, buf);
> +}
> +
> +static struct videobuf_queue_ops mx2_videobuf_ops = {
> +	.buf_setup      = mx2_videobuf_setup,
> +	.buf_prepare    = mx2_videobuf_prepare,
> +	.buf_queue      = mx2_videobuf_queue,
> +	.buf_release    = mx2_videobuf_release,
> +};
> +
> +static void mx2_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 mx2_camera_dev *pcdev = ici->priv;
> +
> +	videobuf_queue_dma_contig_init(q, &mx2_videobuf_ops, pcdev->dev,
> +			&pcdev->lock, V4L2_BUF_TYPE_VIDEO_CAPTURE,
> +			V4L2_FIELD_NONE, sizeof(struct mx2_buffer), icd);
> +}
> +
> +#define MX2_BUS_FLAGS	(SOCAM_DATAWIDTH_8 | \
> +			SOCAM_MASTER | \
> +			SOCAM_VSYNC_ACTIVE_HIGH | \
> +			SOCAM_VSYNC_ACTIVE_LOW | \
> +			SOCAM_HSYNC_ACTIVE_HIGH | \
> +			SOCAM_HSYNC_ACTIVE_LOW | \
> +			SOCAM_PCLK_SAMPLE_RISING | \
> +			SOCAM_PCLK_SAMPLE_FALLING | \
> +			SOCAM_DATA_ACTIVE_HIGH | \
> +			SOCAM_DATA_ACTIVE_LOW)
> +
> +static int mx27_camera_emma_prp_reset(struct mx2_camera_dev *pcdev)
> +{
> +	u32 cntl;
> +	int count = 0;
> +
> +	cntl = readl(pcdev->base_emma + PRP_CNTL);
> +	writel(PRP_CNTL_SWRST, pcdev->base_emma + PRP_CNTL);
> +	while (count++ < 100) {
> +		if (!(readl(pcdev->base_emma + PRP_CNTL) & PRP_CNTL_SWRST))
> +			return 0;
> +		barrier();
> +		udelay(1);
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static void mx27_camera_emma_buf_init(struct soc_camera_device *icd,
> +		int bytesperline)
> +{
> +	struct soc_camera_host *ici =
> +		to_soc_camera_host(icd->dev.parent);
> +	struct mx2_camera_dev *pcdev = ici->priv;
> +
> +	writel(pcdev->discard_buffer_dma,
> +			pcdev->base_emma + PRP_DEST_RGB1_PTR);
> +	writel(pcdev->discard_buffer_dma,
> +			pcdev->base_emma + PRP_DEST_RGB2_PTR);
> +
> +	/*
> +	 * We only use the EMMA engine to get rid of the broken
> +	 * DMA Engine. No color space consversion at the moment.
> +	 * We adjust incoming and outgoing pixelformat to rgb16
> +	 * and adjust the bytesperline accordingly.
> +	 */
> +	writel(PRP_CNTL_CH1EN |
> +			PRP_CNTL_CSIEN |
> +			PRP_CNTL_DATA_IN_RGB16 |
> +			PRP_CNTL_CH1_OUT_RGB16 |
> +			PRP_CNTL_CH1_LEN |
> +			PRP_CNTL_CH1BYP |
> +			PRP_CNTL_CH1_TSKIP(0) |
> +			PRP_CNTL_IN_TSKIP(0),

Ok, already this hard-codes 16 bit RGB in and out... If there's no 
sufficient man-power resp. financing for a proper implementation of a 
dynamic eMMA configuration, how about checking for 16bpp in try_fmt / 
set_fmt?

> +			pcdev->base_emma + PRP_CNTL);
> +
> +	writel(((bytesperline >> 1) << 16) | icd->user_height,
> +			pcdev->base_emma + PRP_SRC_FRAME_SIZE);
> +	writel(((bytesperline >> 1) << 16) | icd->user_height,
> +			pcdev->base_emma + PRP_CH1_OUT_IMAGE_SIZE);
> +	writel(bytesperline,
> +			pcdev->base_emma + PRP_DEST_CH1_LINE_STRIDE);
> +	writel(0x2ca00565,
> +			pcdev->base_emma + PRP_SRC_PIXEL_FORMAT_CNTL);
> +	writel(0x2ca00565,
> +			pcdev->base_emma + PRP_CH1_PIXEL_FORMAT_CNTL);

"565" means 5 bits for red and blue, 6 bits for green. but 0x2ca0 I cannot 
understand either. This seems to mean: 44 bits offset to the red or Y 
component in the pixel, 10 bits to green / U (Cb) component, and 0 bits to 
the V (Cr) component... Ah, I see, error in the Figure:( So, it's 11 bits 
offset to red, 5 bits to green, 0 to blue, so, it's RGB565. This means, 
also this register has to be adjusted for other pixel formats, or at least 
other bits-per-pixel values, if no pixel format specific processing is 
performed.

> +
> +	/* Enable interrupts */
> +	writel(PRP_INTR_RDERR |
> +			PRP_INTR_CH1WERR |
> +			PRP_INTR_CH2WERR |
> +			PRP_INTR_CH1FC |
> +			PRP_INTR_CH2FC |
> +			PRP_INTR_LBOVF |
> +			PRP_INTR_CH2OVF,
> +			pcdev->base_emma + PRP_INTR_CNTL);
> +}
> +
> +static int mx2_camera_set_bus_param(struct soc_camera_device *icd,
> +		__u32 pixfmt)
> +{
> +	struct soc_camera_host *ici =
> +		to_soc_camera_host(icd->dev.parent);
> +	struct mx2_camera_dev *pcdev = ici->priv;
> +	unsigned long camera_flags, common_flags;
> +	int ret = 0;
> +	int bytesperline;
> +	u32 csicr1 = pcdev->csicr1;
> +
> +	camera_flags = icd->ops->query_bus_param(icd);
> +
> +	common_flags = soc_camera_bus_param_compatible(camera_flags,
> +				MX2_BUS_FLAGS);
> +	if (!common_flags)
> +		return -EINVAL;
> +
> +	if ((common_flags & SOCAM_HSYNC_ACTIVE_HIGH) &&
> +	    (common_flags & SOCAM_HSYNC_ACTIVE_LOW)) {
> +		if (pcdev->platform_flags & MX2_CAMERA_HSYNC_HIGH)
> +			common_flags &= ~SOCAM_HSYNC_ACTIVE_LOW;
> +		else
> +			common_flags &= ~SOCAM_HSYNC_ACTIVE_HIGH;
> +	}
> +
> +	if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
> +	    (common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
> +		if (pcdev->platform_flags & MX2_CAMERA_PCLK_SAMPLE_RISING)
> +			common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
> +		else
> +			common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
> +	}
> +
> +	ret = icd->ops->set_bus_param(icd, common_flags);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (common_flags & SOCAM_PCLK_SAMPLE_FALLING)
> +		csicr1 |= CSICR1_INV_PCLK;
> +	if (common_flags & SOCAM_VSYNC_ACTIVE_HIGH)
> +		csicr1 |= CSICR1_SOF_POL;
> +	if (common_flags & SOCAM_HSYNC_ACTIVE_HIGH)
> +		csicr1 |= CSICR1_HSYNC_POL;
> +	if (pcdev->platform_flags & MX2_CAMERA_SWAP16)
> +		csicr1 |= CSICR1_SWAP16_EN;
> +	if (pcdev->platform_flags & MX2_CAMERA_EXT_VSYNC)
> +		csicr1 |= CSICR1_EXT_VSYNC;
> +	if (pcdev->platform_flags & MX2_CAMERA_CCIR)
> +		csicr1 |= CSICR1_CCIR_EN;
> +	if (pcdev->platform_flags & MX2_CAMERA_CCIR_INTERLACE)
> +		csicr1 |= CSICR1_CCIR_MODE;
> +	if (pcdev->platform_flags & MX2_CAMERA_GATED_CLOCK)
> +		csicr1 |= CSICR1_GCLK_MODE;
> +	if (pcdev->platform_flags & MX2_CAMERA_INV_DATA)
> +		csicr1 |= CSICR1_INV_DATA;
> +	if (pcdev->platform_flags & MX2_CAMERA_PACK_DIR_MSB)
> +		csicr1 |= CSICR1_PACK_DIR;
> +
> +	pcdev->csicr1 = csicr1;
> +
> +	bytesperline = soc_mbus_bytes_per_line(icd->user_width,
> +			icd->current_fmt->host_fmt);
> +	if (bytesperline < 0)
> +		return bytesperline;
> +
> +	if (mx27_camera_emma(pcdev)) {
> +		ret = mx27_camera_emma_prp_reset(pcdev);
> +		if (ret)
> +			return ret;
> +
> +		if (pcdev->discard_buffer)
> +			dma_free_coherent(ici->v4l2_dev.dev,
> +				pcdev->discard_size, pcdev->discard_buffer,
> +				pcdev->discard_buffer_dma);
> +
> +		/*
> +		 * I didn't manage to properly enable/disable the prp
> +		 * on a per frame basis during running transfers,
> +		 * thus we allocate a buffer here and use it to
> +		 * discard frames when no buffer is available.
> +		 * Feel free to work on this ;)
> +		 */
> +		pcdev->discard_size = icd->user_height * bytesperline;
> +		pcdev->discard_buffer = dma_alloc_coherent(ici->v4l2_dev.dev,
> +				pcdev->discard_size, &pcdev->discard_buffer_dma,
> +				GFP_KERNEL);
> +		if (!pcdev->discard_buffer)
> +			return -ENOMEM;
> +
> +		mx27_camera_emma_buf_init(icd, bytesperline);
> +	} else if (cpu_is_mx25()) {
> +		writel((bytesperline * icd->user_height) >> 2,
> +				pcdev->base_csi + CSIRXCNT);
> +		writel((bytesperline << 16) | icd->user_height,
> +				pcdev->base_csi + CSIIMAG_PARA);
> +	}
> +
> +	writel(pcdev->csicr1, pcdev->base_csi + CSICR1);
> +
> +	return 0;
> +}
> +
> +static int mx2_camera_set_crop(struct soc_camera_device *icd,
> +				struct v4l2_crop *a)
> +{
> +	struct v4l2_rect *rect = &a->c;
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	struct v4l2_mbus_framefmt mf;
> +	int ret;
> +
> +	soc_camera_limit_side(&rect->left, &rect->width, 0, 2, 4096);
> +	soc_camera_limit_side(&rect->top, &rect->height, 0, 2, 4096);
> +
> +	ret = v4l2_subdev_call(sd, video, s_crop, a);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* The capture device might have changed its output  */
> +	ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_dbg(icd->dev.parent, "Sensor cropped %dx%d\n",
> +		mf.width, mf.height);
> +
> +	icd->user_width		= mf.width;
> +	icd->user_height	= mf.height;
> +
> +	return ret;
> +}
> +
> +static int mx2_camera_set_fmt(struct soc_camera_device *icd,
> +			       struct v4l2_format *f)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	const struct soc_camera_format_xlate *xlate;
> +	struct v4l2_pix_format *pix = &f->fmt.pix;
> +	struct v4l2_mbus_framefmt mf;
> +	int ret;
> +
> +	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> +	if (!xlate) {
> +		dev_warn(icd->dev.parent, "Format %x not found\n",
> +				pix->pixelformat);
> +		return -EINVAL;
> +	}
> +
> +	mf.width	= pix->width;
> +	mf.height	= pix->height;
> +	mf.field	= pix->field;
> +	mf.colorspace	= pix->colorspace;
> +	mf.code		= xlate->code;
> +
> +	ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
> +	if (ret < 0 && ret != -ENOIOCTLCMD)
> +		return ret;
> +
> +	if (mf.code != xlate->code)
> +		return -EINVAL;
> +
> +	pix->width		= mf.width;
> +	pix->height		= mf.height;
> +	pix->field		= mf.field;
> +	pix->colorspace		= mf.colorspace;
> +	icd->current_fmt	= xlate;
> +
> +	return 0;
> +}
> +
> +static int mx2_camera_try_fmt(struct soc_camera_device *icd,
> +				  struct v4l2_format *f)
> +{
> +	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
> +	const struct soc_camera_format_xlate *xlate;
> +	struct v4l2_pix_format *pix = &f->fmt.pix;
> +	struct v4l2_mbus_framefmt mf;
> +	__u32 pixfmt = pix->pixelformat;
> +	unsigned int width_limit;
> +	int ret;
> +
> +	xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
> +	if (pixfmt && !xlate) {
> +		dev_warn(icd->dev.parent, "Format %x not found\n", pixfmt);
> +		return -EINVAL;
> +	}
> +
> +	/* FIXME: implement MX27 limits */
> +
> +	/* limit to MX25 hardware capabilities */
> +	if (cpu_is_mx25()) {
> +		if (xlate->host_fmt->bits_per_sample <= 8)
> +			width_limit = 0xffff * 4;
> +		else
> +			width_limit = 0xffff * 2;
> +		/* CSIIMAG_PARA limit */
> +		if (pix->width > width_limit)
> +			pix->width = width_limit;
> +		if (pix->height > 0xffff)
> +			pix->height = 0xffff;
> +
> +		pix->bytesperline = soc_mbus_bytes_per_line(pix->width,
> +				xlate->host_fmt);
> +		if (pix->bytesperline < 0)
> +			return pix->bytesperline;
> +		pix->sizeimage = pix->height * pix->bytesperline;
> +		if (pix->sizeimage > (4 * 0x3ffff)) { /* CSIRXCNT limit */
> +			dev_warn(icd->dev.parent,
> +					"Image size (%u) above limit\n",
> +					pix->sizeimage);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	/* limit to sensor capabilities */
> +	mf.width	= pix->width;
> +	mf.height	= pix->height;
> +	mf.field	= pix->field;
> +	mf.colorspace	= pix->colorspace;
> +	mf.code		= xlate->code;
> +
> +	ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
> +	if (ret < 0)
> +		return ret;
> +
> +	pix->width	= mf.width;
> +	pix->height	= mf.height;
> +	pix->colorspace	= mf.colorspace;
> +
> +	if (mf.field == V4L2_FIELD_ANY)
> +		mf.field = V4L2_FIELD_NONE;
> +	if (mf.field != V4L2_FIELD_NONE) {
> +		dev_err(icd->dev.parent, "Field type %d unsupported.\n",
> +				mf.field);
> +		return -EINVAL;
> +	}

You have to set pix->field, just setting mf.field doesn't bring much. 
Actually, I think, you have to set pix->field always after the respective 
call to the subdev, other soc-camera drivers could be improved in this 
respect.

> +
> +	return 0;
> +}
> +
> +static int mx2_camera_querycap(struct soc_camera_host *ici,
> +			       struct v4l2_capability *cap)
> +{
> +	/* cap->name is set by the friendly caller:-> */
> +	strlcpy(cap->card, MX2_CAM_DRIVER_DESCRIPTION, sizeof(cap->card));
> +	cap->version = MX2_CAM_VERSION_CODE;
> +	cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
> +
> +	return 0;
> +}
> +
> +static int mx2_camera_reqbufs(struct soc_camera_file *icf,
> +			      struct v4l2_requestbuffers *p)
> +{
> +	int i;
> +
> +	for (i = 0; i < p->count; i++) {
> +		struct mx2_buffer *buf = container_of(icf->vb_vidq.bufs[i],
> +						      struct mx2_buffer, vb);
> +		INIT_LIST_HEAD(&buf->vb.queue);
> +	}
> +
> +	return 0;
> +}
> +
> +static void mx27_camera_frame_done(struct mx2_camera_dev *pcdev, int state)
> +{
> +	struct videobuf_buffer *vb;
> +	struct mx2_buffer *buf;
> +	unsigned long flags;
> +	int ret;
> +
> +	spin_lock_irqsave(&pcdev->lock, flags);
> +
> +	if (!pcdev->active) {
> +		dev_err(pcdev->dev, "%s called with no active buffer!\n",
> +				__func__);
> +		goto out;
> +	}
> +
> +	vb = &pcdev->active->vb;
> +	buf = container_of(vb, struct mx2_buffer, vb);
> +	WARN_ON(list_empty(&vb->queue));
> +	dev_dbg(pcdev->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
> +		vb, vb->baddr, vb->bsize);
> +
> +	/* _init is used to debug races, see comment in pxa_camera_reqbufs() */
> +	list_del_init(&vb->queue);
> +	vb->state = state;
> +	do_gettimeofday(&vb->ts);
> +	vb->field_count++;
> +
> +	wake_up(&vb->done);
> +
> +	if (list_empty(&pcdev->capture)) {
> +		pcdev->active = NULL;
> +		goto out;
> +	}
> +
> +	pcdev->active = list_entry(pcdev->capture.next,
> +			struct mx2_buffer, vb.queue);
> +
> +	vb = &pcdev->active->vb;
> +	vb->state = VIDEOBUF_ACTIVE;
> +
> +	ret = imx_dma_setup_single(pcdev->dma, videobuf_to_dma_contig(vb),
> +			vb->size, (u32)pcdev->base_csi + 0x10, DMA_MODE_READ);

You missed this location from Sascha's patch, this wasn't on purpose, was 
it?

> +	if (ret) {
> +		vb->state = VIDEOBUF_ERROR;
> +		pcdev->active = NULL;
> +		wake_up(&vb->done);
> +	}
> +
> +out:
> +	spin_unlock_irqrestore(&pcdev->lock, flags);
> +}
> +
> +static void mx27_camera_dma_err_callback(int channel, void *data, int err)
> +{
> +	struct mx2_camera_dev *pcdev = data;
> +
> +	mx27_camera_frame_done(pcdev, VIDEOBUF_ERROR);
> +}
> +
> +static void mx27_camera_dma_callback(int channel, void *data)
> +{
> +	struct mx2_camera_dev *pcdev = data;
> +
> +	mx27_camera_frame_done(pcdev, VIDEOBUF_DONE);
> +}
> +
> +#define DMA_REQ_CSI_RX          31 /* FIXME: Add this to a resource */
> +
> +static int __devinit mx27_camera_dma_init(struct platform_device *pdev,
> +		struct mx2_camera_dev *pcdev)
> +{
> +	int err;
> +
> +	pcdev->dma = imx_dma_request_by_prio("CSI RX DMA", DMA_PRIO_HIGH);
> +	if (pcdev->dma < 0) {
> +		dev_err(&pdev->dev, "%s failed to request DMA channel\n",
> +				__func__);
> +		return pcdev->dma;
> +	}
> +
> +	err = imx_dma_setup_handlers(pcdev->dma, mx27_camera_dma_callback,
> +					mx27_camera_dma_err_callback, pcdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "%s failed to set DMA callback\n",
> +				__func__);
> +		goto err_out;
> +	}
> +
> +	err = imx_dma_config_channel(pcdev->dma,
> +			IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_FIFO,
> +			IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
> +			DMA_REQ_CSI_RX, 1);
> +	if (err) {
> +		dev_err(&pdev->dev, "%s failed to config DMA channel\n",
> +				__func__);
> +		goto err_out;
> +	}
> +
> +	imx_dma_config_burstlen(pcdev->dma, 64);
> +
> +	return 0;
> +
> +err_out:
> +	imx_dma_free(pcdev->dma);
> +
> +	return err;
> +}
> +
> +static unsigned int mx2_camera_poll(struct file *file, poll_table *pt)
> +{
> +	struct soc_camera_file *icf = file->private_data;
> +
> +	return videobuf_poll_stream(file, &icf->vb_vidq, pt);
> +}
> +
> +static struct soc_camera_host_ops mx2_soc_camera_host_ops = {
> +	.owner		= THIS_MODULE,
> +	.add		= mx2_camera_add_device,
> +	.remove		= mx2_camera_remove_device,
> +	.set_fmt	= mx2_camera_set_fmt,
> +	.set_crop	= mx2_camera_set_crop,
> +	.try_fmt	= mx2_camera_try_fmt,
> +	.init_videobuf	= mx2_camera_init_videobuf,
> +	.reqbufs	= mx2_camera_reqbufs,
> +	.poll		= mx2_camera_poll,
> +	.querycap	= mx2_camera_querycap,
> +	.set_bus_param	= mx2_camera_set_bus_param,
> +};
> +
> +static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
> +		int bufnum, int state)
> +{
> +	struct mx2_buffer *buf;
> +	struct videobuf_buffer *vb;
> +	unsigned long phys;
> +
> +	if (!list_empty(&pcdev->active_bufs)) {
> +		buf = list_entry(pcdev->active_bufs.next,
> +			struct mx2_buffer, vb.queue);
> +
> +		if (buf->bufnum == bufnum) {

You didn't address this issue.

> +			vb = &buf->vb;
> +#ifdef DEBUG
> +			phys = videobuf_to_dma_contig(vb);
> +			if (readl(pcdev->base_emma + PRP_DEST_RGB1_PTR +
> +						4 * bufnum) != phys) {
> +				dev_err(pcdev->dev, "%p != %p\n", phys,
> +						readl(pcdev->base_emma +
> +						PRP_DEST_RGB1_PTR +
> +						4 * bufnum));
> +			}
> +#endif
> +			dev_dbg(pcdev->dev, "%s (vb=0x%p) 0x%08lx %d\n",
> +					__func__, vb, vb->baddr, vb->bsize);
> +
> +			list_del(&vb->queue);
> +			vb->state = state;
> +			do_gettimeofday(&vb->ts);
> +			vb->field_count++;
> +
> +			wake_up(&vb->done);
> +		}
> +	}
> +
> +	if (list_empty(&pcdev->capture)) {
> +		writel(pcdev->discard_buffer_dma, pcdev->base_emma +
> +				PRP_DEST_RGB1_PTR + 4 * bufnum);
> +		return;
> +	}
> +
> +	buf = list_entry(pcdev->capture.next,
> +			struct mx2_buffer, vb.queue);
> +
> +	buf->bufnum = bufnum;
> +
> +	list_move_tail(pcdev->capture.next, &pcdev->active_bufs);
> +
> +	vb = &buf->vb;
> +	vb->state = VIDEOBUF_ACTIVE;
> +
> +	phys = videobuf_to_dma_contig(vb);
> +	writel(phys, pcdev->base_emma + PRP_DEST_RGB1_PTR + 4 * bufnum);
> +}
> +
> +static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
> +{
> +	struct mx2_camera_dev *pcdev = data;
> +	unsigned int status = readl(pcdev->base_emma + PRP_INTRSTATUS);
> +
> +	if (status & (1 << 6))
> +		mx27_camera_frame_done_emma(pcdev, 0, VIDEOBUF_DONE);
> +	if (status & (1 << 5))
> +		mx27_camera_frame_done_emma(pcdev, 1, VIDEOBUF_DONE);
> +	if (status & (1 << 7)) {
> +		u32 cntl;
> +		cntl = readl(pcdev->base_emma + PRP_CNTL);
> +		writel(cntl & ~PRP_CNTL_CH1EN, pcdev->base_emma + PRP_CNTL);
> +		writel(cntl, pcdev->base_emma + PRP_CNTL);

Given Sascha's explanation, please, at least provide an explanatory 
comment, maybe as a "TODO."

> +	}
> +
> +	writel(status, pcdev->base_emma + PRP_INTRSTATUS);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __devinit mx27_camera_emma_init(struct mx2_camera_dev *pcdev)
> +{
> +	struct resource *res_emma = pcdev->res_emma;
> +	int err = 0;
> +
> +	if (!request_mem_region(res_emma->start, resource_size(res_emma),
> +				MX2_CAM_DRV_NAME)) {
> +		err = -EBUSY;
> +		goto out;
> +	}
> +
> +	pcdev->base_emma = ioremap(res_emma->start, resource_size(res_emma));
> +	if (!pcdev->base_emma) {
> +		err = -ENOMEM;
> +		goto exit_release;
> +	}
> +
> +	err = request_irq(pcdev->irq_emma, mx27_camera_emma_irq, 0,
> +			MX2_CAM_DRV_NAME, pcdev);
> +	if (err) {
> +		dev_err(pcdev->dev, "Camera EMMA interrupt register failed \n");
> +		goto exit_iounmap;
> +	}
> +
> +	pcdev->clk_emma = clk_get(NULL, "emma");
> +	if (IS_ERR(pcdev->clk_emma)) {
> +		err = PTR_ERR(pcdev->clk_emma);
> +		goto exit_free_irq;
> +	}
> +
> +	clk_enable(pcdev->clk_emma);
> +
> +	err = mx27_camera_emma_prp_reset(pcdev);
> +	if (err)
> +		goto exit_clk_emma_put;
> +
> +	return err;
> +
> +exit_clk_emma_put:
> +	clk_disable(pcdev->clk_emma);
> +	clk_put(pcdev->clk_emma);
> +exit_free_irq:
> +	free_irq(pcdev->irq_emma, pcdev);
> +exit_iounmap:
> +	iounmap(pcdev->base_emma);
> +exit_release:
> +	release_mem_region(res_emma->start, resource_size(res_emma));
> +out:
> +	return err;
> +}
> +
> +static int __devinit mx2_camera_probe(struct platform_device *pdev)
> +{
> +	struct mx2_camera_dev *pcdev;
> +	struct resource *res_csi, *res_emma;
> +	void __iomem *base_csi;
> +	int irq_csi, irq_emma;
> +	irq_handler_t mx2_cam_irq_handler = cpu_is_mx25() ? mx25_camera_irq
> +		: mx27_camera_irq;
> +	int err = 0;
> +
> +	dev_dbg(&pdev->dev, "initialising\n");
> +
> +	res_csi = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	irq_csi = platform_get_irq(pdev, 0);
> +	if (res_csi == NULL || irq_csi < 0) {
> +		dev_err(&pdev->dev, "Missing platform resources data\n");
> +		err = -ENODEV;
> +		goto exit;
> +	}
> +
> +	pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
> +	if (!pcdev) {
> +		dev_err(&pdev->dev, "Could not allocate pcdev\n");
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	pcdev->clk_csi = clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(pcdev->clk_csi)) {
> +		err = PTR_ERR(pcdev->clk_csi);
> +		goto exit_kfree;
> +	}
> +
> +	dev_dbg(&pdev->dev, "Camera clock frequency: %ld\n",
> +			clk_get_rate(pcdev->clk_csi));
> +
> +	/* Initialize DMA */
> +	if (cpu_is_mx27()) {
> +		err = mx27_camera_dma_init(pdev, pcdev);
> +		if (err)
> +			goto exit_clk_put;
> +	}
> +
> +	pcdev->res_csi = res_csi;
> +	pcdev->pdata = pdev->dev.platform_data;
> +	if (pcdev->pdata) {
> +		long rate;
> +
> +		pcdev->platform_flags = pcdev->pdata->flags;
> +
> +		rate = clk_round_rate(pcdev->clk_csi, pcdev->pdata->clk * 2);
> +		if (rate <= 0) {
> +			err = -ENODEV;
> +			goto exit_dma_free;
> +		}
> +		err = clk_set_rate(pcdev->clk_csi, rate);
> +		if (err < 0)
> +			goto exit_dma_free;
> +	}
> +
> +	INIT_LIST_HEAD(&pcdev->capture);
> +	INIT_LIST_HEAD(&pcdev->active_bufs);
> +	spin_lock_init(&pcdev->lock);
> +
> +	/*
> +	 * Request the regions.
> +	 */
> +	if (!request_mem_region(res_csi->start, resource_size(res_csi),
> +				MX2_CAM_DRV_NAME)) {
> +		err = -EBUSY;
> +		goto exit_dma_free;
> +	}
> +
> +	base_csi = ioremap(res_csi->start, resource_size(res_csi));
> +	if (!base_csi) {
> +		err = -ENOMEM;
> +		goto exit_release;
> +	}
> +	pcdev->irq_csi = irq_csi;
> +	pcdev->base_csi = base_csi;
> +	pcdev->base_dma = res_csi->start;
> +	pcdev->dev = &pdev->dev;
> +
> +	err = request_irq(pcdev->irq_csi, mx2_cam_irq_handler, 0,
> +			MX2_CAM_DRV_NAME, pcdev);
> +	if (err) {
> +		dev_err(pcdev->dev, "Camera interrupt register failed \n");
> +		goto exit_iounmap;
> +	}
> +
> +	if (cpu_is_mx27()) {
> +		/* EMMA support */
> +		res_emma = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +		irq_emma = platform_get_irq(pdev, 1);
> +
> +		if (res_emma && irq_emma >= 0) {
> +			dev_info(&pdev->dev, "Using EMMA\n");
> +			pcdev->use_emma = 1;
> +			pcdev->res_emma = res_emma;
> +			pcdev->irq_emma = irq_emma;
> +			if (mx27_camera_emma_init(pcdev))
> +				goto exit_free_irq;
> +		}
> +	}
> +
> +	pcdev->soc_host.drv_name	= MX2_CAM_DRV_NAME,
> +	pcdev->soc_host.ops		= &mx2_soc_camera_host_ops,
> +	pcdev->soc_host.priv		= pcdev;
> +	pcdev->soc_host.v4l2_dev.dev	= &pdev->dev;
> +	pcdev->soc_host.nr		= pdev->id;
> +	err = soc_camera_host_register(&pcdev->soc_host);
> +	if (err)
> +		goto exit_free_emma;
> +
> +	return 0;
> +
> +exit_free_emma:
> +	if (mx27_camera_emma(pcdev)) {
> +		free_irq(pcdev->irq_emma, pcdev);
> +		clk_disable(pcdev->clk_emma);
> +		clk_put(pcdev->clk_emma);
> +		iounmap(pcdev->base_emma);
> +		release_mem_region(res_emma->start, resource_size(res_emma));
> +	}
> +exit_free_irq:
> +	free_irq(pcdev->irq_csi, pcdev);
> +exit_iounmap:
> +	iounmap(base_csi);
> +exit_release:
> +	release_mem_region(res_csi->start, resource_size(res_csi));
> +exit_dma_free:
> +	if (cpu_is_mx27())
> +		imx_dma_free(pcdev->dma);
> +exit_clk_put:
> +	clk_put(pcdev->clk_csi);
> +exit_kfree:
> +	kfree(pcdev);
> +exit:
> +	return err;
> +}
> +
> +static int __devexit mx2_camera_remove(struct platform_device *pdev)
> +{
> +	struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
> +	struct mx2_camera_dev *pcdev = container_of(soc_host,
> +			struct mx2_camera_dev, soc_host);
> +	struct resource *res;
> +
> +	clk_put(pcdev->clk_csi);
> +	if (cpu_is_mx27())
> +		imx_dma_free(pcdev->dma);
> +	free_irq(pcdev->irq_csi, pcdev);
> +	if (mx27_camera_emma(pcdev))
> +		free_irq(pcdev->irq_emma, pcdev);
> +
> +	soc_camera_host_unregister(&pcdev->soc_host);
> +
> +	iounmap(pcdev->base_csi);
> +
> +	if (mx27_camera_emma(pcdev)) {
> +		clk_disable(pcdev->clk_emma);
> +		clk_put(pcdev->clk_emma);
> +		iounmap(pcdev->base_emma);
> +		res = pcdev->res_emma;
> +		release_mem_region(res->start, resource_size(res));
> +	}
> +
> +	res = pcdev->res_csi;
> +	release_mem_region(res->start, resource_size(res));
> +
> +	kfree(pcdev);
> +
> +	dev_info(&pdev->dev, "MX2 Camera driver unloaded\n");
> +
> +	return 0;
> +}
> +
> +static struct platform_driver mx2_camera_driver = {
> +	.driver 	= {
> +		.name	= MX2_CAM_DRV_NAME,
> +	},
> +	.remove		= __devexit_p(mx2_camera_remove),
> +};
> +
> +
> +static int __init mx2_camera_init(void)
> +{
> +	return platform_driver_probe(&mx2_camera_driver, &mx2_camera_probe);
> +}
> +
> +static void __exit mx2_camera_exit(void)
> +{
> +	return platform_driver_unregister(&mx2_camera_driver);
> +}
> +
> +module_init(mx2_camera_init);
> +module_exit(mx2_camera_exit);
> +
> +MODULE_DESCRIPTION("i.MX27/i.MX25 SoC Camera Host driver");
> +MODULE_AUTHOR("Sascha Hauer <sha at pengutronix.de>");
> +MODULE_LICENSE("GPL");
> -- 
> 1.7.1
> 

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/



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