/*
 * Author: Mikhail Ulyanov
 * Copyright (C) 2014-2015 Cogent Embedded, Inc.  <source@cogentembedded.com>
 * Copyright (C) 2014-2015 Renesas Electronics Corporation
 *
 * This is based on the drivers/media/platform/s5p-jpeg driver by
 * Andrzej Pietrasiewicz and Jacek Anaszewski.
 * Some portions of code inspired by VSP1 driver by Laurent Pinchart.
 *
 * TODO in order of priority:
 *      1) Rotation
 *      2) Cropping
 *      3) V4L2_CID_JPEG_ACTIVE_MARKER
 *
 * 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 <asm/unaligned.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.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/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/videodev2.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-contig.h>


#define DRV_NAME "rcar_jpu"

/*
 * Align JPEG header end to cache line to make sure we will not have any issues
 * with cache; additionally to requerment (33.3.27 R01UH0501EJ0100 Rev.1.00)
 */
#define JPU_JPEG_HDR_SIZE		(ALIGN(0x258, L1_CACHE_BYTES))
#define JPU_JPEG_MAX_BYTES_PER_PIXEL	2	/* 16 bit precision format */
#define JPU_JPEG_MIN_SIZE		25	/* SOI + SOF + EOI */
#define JPU_JPEG_QTBL_SIZE		0x40
#define JPU_JPEG_HDCTBL_SIZE		0x1c
#define JPU_JPEG_HACTBL_SIZE		0xb2
#define JPU_JPEG_HEIGHT_OFFSET		0x91
#define JPU_JPEG_WIDTH_OFFSET		0x93
#define JPU_JPEG_SUBS_OFFSET		0x97
#define JPU_JPEG_QTBL_LUM_OFFSET	0x07
#define JPU_JPEG_QTBL_CHR_OFFSET	0x4c
#define JPU_JPEG_HDCTBL_LUM_OFFSET	0xa4
#define JPU_JPEG_HACTBL_LUM_OFFSET	0xc5
#define JPU_JPEG_HDCTBL_CHR_OFFSET	0x17c
#define JPU_JPEG_HACTBL_CHR_OFFSET	0x19d
#define JPU_JPEG_PADDING_OFFSET		0x24f
#define JPU_JPEG_LUM 0x00
#define JPU_JPEG_CHR 0x01
#define JPU_JPEG_DC  0x00
#define JPU_JPEG_AC  0x10

#define JPU_JPEG_422 0x21
#define JPU_JPEG_420 0x22

#define JPU_JPEG_DEFAULT_422_PIX_FMT V4L2_PIX_FMT_NV16M
#define JPU_JPEG_DEFAULT_420_PIX_FMT V4L2_PIX_FMT_NV12M

/* JPEG markers */
#define TEM	0x01
#define SOF0	0xc0
#define RST	0xd0
#define SOI	0xd8
#define EOI	0xd9
#define DHP	0xde
#define DHT	0xc4
#define COM	0xfe
#define DQT	0xdb
#define DRI	0xdd
#define APP0	0xe0

#define JPU_RESET_TIMEOUT	100 /* ms */
#define JPU_JOB_TIMEOUT		300 /* ms */
#define JPU_MAX_QUALITY		4
#define JPU_WIDTH_MIN		16
#define JPU_HEIGHT_MIN		16
#define JPU_WIDTH_MAX		4096
#define JPU_HEIGHT_MAX		4096
#define JPU_MEMALIGN		8

/* Flags that indicate a format can be used for capture/output */
#define JPU_FMT_TYPE_OUTPUT	0
#define JPU_FMT_TYPE_CAPTURE	1
#define JPU_ENC_CAPTURE		(1 << 0)
#define JPU_ENC_OUTPUT		(1 << 1)
#define JPU_DEC_CAPTURE		(1 << 2)
#define JPU_DEC_OUTPUT		(1 << 3)

/*
 * JPEG registers and bits
 */

/* JPEG code mode register */
#define JCMOD	0x00
#define JCMOD_PCTR		(1 << 7)
#define JCMOD_MSKIP_ENABLE	(1 << 5)
#define JCMOD_DSP_ENC		(0 << 3)
#define JCMOD_DSP_DEC		(1 << 3)
#define JCMOD_REDU		(7 << 0)
#define JCMOD_REDU_422		(1 << 0)
#define JCMOD_REDU_420		(2 << 0)

/* JPEG code command register */
#define JCCMD	0x04
#define JCCMD_SRST	(1 << 12)
#define JCCMD_JEND	(1 << 2)
#define JCCMD_JSRT	(1 << 0)

/* JPEG code quantanization table number register */
#define JCQTN	0x0c
#define JCQTN_SHIFT(t)		(((t) - 1) << 1)

/* JPEG code Huffman table number register */
#define JCHTN	0x10
#define JCHTN_AC_SHIFT(t)	(((t) << 1) - 1)
#define JCHTN_DC_SHIFT(t)	(((t) - 1) << 1)

#define JCVSZU	0x1c /* JPEG code vertical size upper register */
#define JCVSZD	0x20 /* JPEG code vertical size lower register */
#define JCHSZU	0x24 /* JPEG code horizontal size upper register */
#define JCHSZD	0x28 /* JPEG code horizontal size lower register */
#define JCSZ_MASK 0xff /* JPEG code h/v size register contains only 1 byte*/

#define JCDTCU	0x2c /* JPEG code data count upper register */
#define JCDTCM	0x30 /* JPEG code data count middle register */
#define JCDTCD	0x34 /* JPEG code data count lower register */

/* JPEG interrupt enable register */
#define JINTE	0x38
#define JINTE_ERR		(7 << 5) /* INT5 + INT6 + INT7 */
#define JINTE_TRANSF_COMPL	(1 << 10)

/* JPEG interrupt status register */
#define JINTS	0x3c
#define JINTS_MASK	0x7c68
#define JINTS_ERR		(1 << 5)
#define JINTS_PROCESS_COMPL	(1 << 6)
#define JINTS_TRANSF_COMPL	(1 << 10)

#define JCDERR	0x40 /* JPEG code decode error register */
#define JCDERR_MASK	0xf /* JPEG code decode error register mask*/

/* JPEG interface encoding */
#define JIFECNT	0x70
#define JIFECNT_INFT_422	0
#define JIFECNT_INFT_420	1
#define JIFECNT_SWAP_WB		(3 << 4) /* to JPU */

#define JIFESYA1	0x74	/* encode source Y address register 1 */
#define JIFESCA1	0x78	/* encode source C address register 1 */
#define JIFESYA2	0x7c	/* encode source Y address register 2 */
#define JIFESCA2	0x80	/* encode source C address register 2 */
#define JIFESMW		0x84	/* encode source memory width register */
#define JIFESVSZ	0x88	/* encode source vertical size register */
#define JIFESHSZ	0x8c	/* encode source horizontal size register */
#define JIFEDA1		0x90	/* encode destination address register 1 */
#define JIFEDA2		0x94	/* encode destination address register 2 */

/* JPEG decoding control register */
#define JIFDCNT	0xa0
#define JIFDCNT_SWAP_WB		(3 << 1) /* from JPU */

#define JIFDSA1		0xa4	/* decode source address register 1 */
#define JIFDDMW		0xb0	/* decode destination  memory width register */
#define JIFDDVSZ	0xb4	/* decode destination  vert. size register */
#define JIFDDHSZ	0xb8	/* decode destination  horiz. size register */
#define JIFDDYA1	0xbc	/* decode destination  Y address register 1 */
#define JIFDDCA1	0xc0	/* decode destination  C address register 1 */

#define JCQTBL(n)	(0x10000 + (n) * 0x40)	/* quantization tables regs */
#define JCHTBD(n)	(0x10100 + (n) * 0x100)	/* Huffman table DC regs */
#define JCHTBA(n)	(0x10120 + (n) * 0x100)	/* Huffman table AC regs */

/**
 * struct jpu - JPEG IP abstraction
 * @mutex: the mutex protecting this structure
 * @lock: spinlock protecting the device contexts
 * @v4l2_dev: v4l2 device for mem2mem mode
 * @vfd_encoder: video device node for encoder mem2mem mode
 * @vfd_decoder: video device node for decoder mem2mem mode
 * @m2m_dev: v4l2 mem2mem device data
 * @curr: pointer to current context
 * @irq_queue:	interrupt handler waitqueue
 * @regs: JPEG IP registers mapping
 * @irq: JPEG IP irq
 * @clk: JPEG IP clock
 * @dev: JPEG IP struct device
 * @alloc_ctx: videobuf2 memory allocator's context
 * @ref_count: reference counter
 */
struct jpu {
	struct mutex	mutex;
	spinlock_t	lock;
	struct v4l2_device	v4l2_dev;
	struct video_device	vfd_encoder;
	struct video_device	vfd_decoder;
	struct v4l2_m2m_dev	*m2m_dev;
	struct jpu_ctx		*curr;
	wait_queue_head_t	irq_queue;

	void __iomem		*regs;
	unsigned int		irq;
	struct clk		*clk;
	struct device		*dev;
	void			*alloc_ctx;
	int			ref_count;
};

/**
 * struct jpu_buffer - driver's specific video buffer
 * @buf: m2m buffer
 * @compr_quality: destination image quality in compression mode
 * @subsampling: source image subsampling in decompression mode
 */
struct jpu_buffer {
	struct v4l2_m2m_buffer buf;
	unsigned short	compr_quality;
	unsigned char	subsampling;
};

/**
 * struct jpu_fmt - driver's internal format data
 * @fourcc: the fourcc code, 0 if not applicable
 * @colorspace: the colorspace specifier
 * @bpp: number of bits per pixel per plane
 * @h_align: horizontal alignment order (align to 2^h_align)
 * @v_align: vertical alignment order (align to 2^v_align)
 * @subsampling: (horizontal:4 | vertical:4) subsampling factor
 * @num_planes: number of planes
 * @types: types of queue this format is applicable to
 */
struct jpu_fmt {
	u32 fourcc;
	u32 colorspace;
	u8 bpp[2];
	u8 h_align;
	u8 v_align;
	u8 subsampling;
	u8 num_planes;
	u16 types;
};

/**
 * jpu_q_data - parameters of one queue
 * @fmtinfo: driver-specific format of this queue
 * @format: multiplanar format of this queue
 * @sequence: sequence number
 */
struct jpu_q_data {
	struct jpu_fmt *fmtinfo;
	struct v4l2_pix_format_mplane format;
	unsigned int sequence;
};

/**
 * jpu_ctx - the device context data
 * @jpu: JPEG IP device for this context
 * @encoder: compression (encode) operation or decompression (decode)
 * @compr_quality: destination image quality in compression (encode) mode
 * @out_q: source (output) queue information
 * @cap_q: destination (capture) queue information
 * @fh: file handler
 * @ctrl_handler: controls handler
 */
struct jpu_ctx {
	struct jpu		*jpu;
	bool			encoder;
	unsigned short		compr_quality;
	struct jpu_q_data	out_q;
	struct jpu_q_data	cap_q;
	struct v4l2_fh		fh;
	struct v4l2_ctrl_handler ctrl_handler;
};

 /**
 * jpeg_buffer - description of memory containing input JPEG data
 * @end: end position in the buffer
 * @curr: current position in the buffer
 */
struct jpeg_buffer {
	void *end;
	void *curr;
};

static struct jpu_fmt jpu_formats[] = {
	{ V4L2_PIX_FMT_JPEG, V4L2_COLORSPACE_JPEG,
	  {0, 0}, 0, 0, 0, 1, JPU_ENC_CAPTURE | JPU_DEC_OUTPUT },
	{ V4L2_PIX_FMT_NV16M, V4L2_COLORSPACE_SRGB,
	  {8, 8}, 2, 2, JPU_JPEG_422, 2, JPU_ENC_OUTPUT | JPU_DEC_CAPTURE },
	{ V4L2_PIX_FMT_NV12M, V4L2_COLORSPACE_SRGB,
	  {8, 4}, 2, 2, JPU_JPEG_420, 2, JPU_ENC_OUTPUT | JPU_DEC_CAPTURE },
	{ V4L2_PIX_FMT_NV16, V4L2_COLORSPACE_SRGB,
	  {16, 0}, 2, 2, JPU_JPEG_422, 1, JPU_ENC_OUTPUT | JPU_DEC_CAPTURE },
	{ V4L2_PIX_FMT_NV12, V4L2_COLORSPACE_SRGB,
	  {12, 0}, 2, 2, JPU_JPEG_420, 1, JPU_ENC_OUTPUT | JPU_DEC_CAPTURE },
};

static const u8 zigzag[] = {
	0x03, 0x02, 0x0b, 0x13, 0x0a, 0x01, 0x00, 0x09,
	0x12, 0x1b, 0x23, 0x1a, 0x11, 0x08, 0x07, 0x06,
	0x0f, 0x10, 0x19, 0x22, 0x2b, 0x33, 0x2a, 0x21,
	0x18, 0x17, 0x0e, 0x05, 0x04, 0x0d, 0x16, 0x1f,
	0x20, 0x29, 0x32, 0x3b, 0x3a, 0x31, 0x28, 0x27,
	0x1e, 0x15, 0x0e, 0x14, 0x10, 0x26, 0x2f, 0x30,
	0x39, 0x38, 0x37, 0x2e, 0x25, 0x1c, 0x24, 0x2b,
	0x36, 0x3f, 0x3e, 0x35, 0x2c, 0x34, 0x3d, 0x3c
};

#define QTBL_SIZE (ALIGN(JPU_JPEG_QTBL_SIZE, \
			  sizeof(unsigned int)) / sizeof(unsigned int))
#define HDCTBL_SIZE (ALIGN(JPU_JPEG_HDCTBL_SIZE, \
			  sizeof(unsigned int)) / sizeof(unsigned int))
#define HACTBL_SIZE (ALIGN(JPU_JPEG_HACTBL_SIZE, \
			  sizeof(unsigned int)) / sizeof(unsigned int))
/*
 * Start of image; Quantization tables
 * SOF0 (17 bytes payload) is Baseline DCT - Sample precision, height, width,
 * Number of image components, (Ci:8 - Hi:4 - Vi:4 - Tq:8) * 3 - Y,Cb,Cr;
 * Huffman tables; Padding with 0xff (33.3.27 R01UH0501EJ0100 Rev.1.00)
 */
#define JPU_JPEG_HDR_BLOB {                                                    \
	0xff, SOI, 0xff, DQT, 0x00, JPU_JPEG_QTBL_SIZE + 0x3, JPU_JPEG_LUM,    \
	[JPU_JPEG_QTBL_LUM_OFFSET ...                                          \
		JPU_JPEG_QTBL_LUM_OFFSET + JPU_JPEG_QTBL_SIZE - 1] = 0x00,     \
	0xff, DQT, 0x00, JPU_JPEG_QTBL_SIZE + 0x3, JPU_JPEG_CHR,               \
	[JPU_JPEG_QTBL_CHR_OFFSET ... JPU_JPEG_QTBL_CHR_OFFSET +               \
		JPU_JPEG_QTBL_SIZE - 1] = 0x00, 0xff, SOF0, 0x00, 0x11, 0x08,  \
	[JPU_JPEG_HEIGHT_OFFSET ... JPU_JPEG_HEIGHT_OFFSET + 1] = 0x00,        \
	[JPU_JPEG_WIDTH_OFFSET ... JPU_JPEG_WIDTH_OFFSET + 1] = 0x00,          \
	0x03, 0x01, [JPU_JPEG_SUBS_OFFSET] = 0x00, JPU_JPEG_LUM,               \
	0x02, 0x11, JPU_JPEG_CHR, 0x03, 0x11, JPU_JPEG_CHR,                    \
	0xff, DHT, 0x00, JPU_JPEG_HDCTBL_SIZE + 0x3, JPU_JPEG_LUM|JPU_JPEG_DC, \
	[JPU_JPEG_HDCTBL_LUM_OFFSET ...                                        \
		JPU_JPEG_HDCTBL_LUM_OFFSET + JPU_JPEG_HDCTBL_SIZE - 1] = 0x00, \
	0xff, DHT, 0x00, JPU_JPEG_HACTBL_SIZE + 0x3, JPU_JPEG_LUM|JPU_JPEG_AC, \
	[JPU_JPEG_HACTBL_LUM_OFFSET ...                                        \
		JPU_JPEG_HACTBL_LUM_OFFSET + JPU_JPEG_HACTBL_SIZE - 1] = 0x00, \
	0xff, DHT, 0x00, JPU_JPEG_HDCTBL_SIZE + 0x3, JPU_JPEG_CHR|JPU_JPEG_DC, \
	[JPU_JPEG_HDCTBL_CHR_OFFSET ...                                        \
		JPU_JPEG_HDCTBL_CHR_OFFSET + JPU_JPEG_HDCTBL_SIZE - 1] = 0x00, \
	0xff, DHT, 0x00, JPU_JPEG_HACTBL_SIZE + 0x3, JPU_JPEG_CHR|JPU_JPEG_AC, \
	[JPU_JPEG_HACTBL_CHR_OFFSET ...                                        \
		JPU_JPEG_HACTBL_CHR_OFFSET + JPU_JPEG_HACTBL_SIZE - 1] = 0x00, \
	[JPU_JPEG_PADDING_OFFSET ... JPU_JPEG_HDR_SIZE - 1] = 0xff             \
}

static unsigned char jpeg_hdrs[JPU_MAX_QUALITY][JPU_JPEG_HDR_SIZE] = {
	[0 ... JPU_MAX_QUALITY - 1] = JPU_JPEG_HDR_BLOB
};

static const unsigned int qtbl_lum[JPU_MAX_QUALITY][QTBL_SIZE] = {
	{
		0x14101927, 0x322e3e44, 0x10121726, 0x26354144,
		0x19171f26, 0x35414444, 0x27262635, 0x41444444,
		0x32263541, 0x44444444, 0x2e354144, 0x44444444,
		0x3e414444, 0x44444444, 0x44444444, 0x44444444
	},
	{
		0x100b0b10, 0x171b1f1e, 0x0b0c0c0f, 0x1417171e,
		0x0b0c0d10, 0x171a232f, 0x100f1017, 0x1a252f40,
		0x1714171a, 0x27334040, 0x1b171a25, 0x33404040,
		0x1f17232f, 0x40404040, 0x1e1e2f40, 0x40404040
	},
	{
		0x0c08080c, 0x11151817, 0x0809090b, 0x0f131217,
		0x08090a0c, 0x13141b24, 0x0c0b0c15, 0x141c2435,
		0x110f1314, 0x1e27333b, 0x1513141c, 0x27333b3b,
		0x18121b24, 0x333b3b3b, 0x17172435, 0x3b3b3b3b
	},
	{
		0x08060608, 0x0c0e1011, 0x06060608, 0x0a0d0c0f,
		0x06060708, 0x0d0e1218, 0x0808080e, 0x0d131823,
		0x0c0a0d0d, 0x141a2227, 0x0e0d0e13, 0x1a222727,
		0x100c1318, 0x22272727, 0x110f1823, 0x27272727
	}
};

static const unsigned int qtbl_chr[JPU_MAX_QUALITY][QTBL_SIZE] = {
	{
		0x15192026, 0x36444444, 0x191c1826, 0x36444444,
		0x2018202b, 0x42444444, 0x26262b35, 0x44444444,
		0x36424444, 0x44444444, 0x44444444, 0x44444444,
		0x44444444, 0x44444444, 0x44444444, 0x44444444
	},
	{
		0x110f1115, 0x141a2630, 0x0f131211, 0x141a232b,
		0x11121416, 0x1a1e2e35, 0x1511161c, 0x1e273540,
		0x14141a1e, 0x27304040, 0x1a1a1e27, 0x303f4040,
		0x26232e35, 0x40404040, 0x302b3540, 0x40404040
	},
	{
		0x0d0b0d10, 0x14141d25, 0x0b0e0e0e, 0x10141a20,
		0x0d0e0f11, 0x14172328, 0x100e1115, 0x171e2832,
		0x14101417, 0x1e25323b, 0x1414171e, 0x25303b3b,
		0x1d1a2328, 0x323b3b3b, 0x25202832, 0x3b3b3b3b
	},
	{
		0x0908090b, 0x0e111318, 0x080a090b, 0x0e0d1116,
		0x09090d0e, 0x0d0f171a, 0x0b0b0e0e, 0x0f141a21,
		0x0e0e0d0f, 0x14182127, 0x110d0f14, 0x18202727,
		0x1311171a, 0x21272727, 0x18161a21, 0x27272727
	}
};

static const unsigned int hdctbl_lum[HDCTBL_SIZE] = {
	0x00010501, 0x01010101, 0x01000000, 0x00000000,
	0x00010203, 0x04050607, 0x08090a0b
};

static const unsigned int hdctbl_chr[HDCTBL_SIZE] = {
	0x00010501, 0x01010101, 0x01000000, 0x00000000,
	0x00010203, 0x04050607, 0x08090a0b
};

static const unsigned int hactbl_lum[HACTBL_SIZE] = {
	0x00020103, 0x03020403, 0x05050404, 0x0000017d, 0x01020300, 0x04110512,
	0x21314106, 0x13516107,	0x22711432, 0x8191a108, 0x2342b1c1, 0x1552d1f0,
	0x24336272, 0x82090a16, 0x1718191a, 0x25262728, 0x292a3435, 0x36373839,
	0x3a434445, 0x46474849, 0x4a535455, 0x56575859, 0x5a636465, 0x66676869,
	0x6a737475, 0x76777879, 0x7a838485, 0x86878889, 0x8a929394, 0x95969798,
	0x999aa2a3, 0xa4a5a6a7, 0xa8a9aab2, 0xb3b4b5b6, 0xb7b8b9ba, 0xc2c3c4c5,
	0xc6c7c8c9, 0xcad2d3d4, 0xd5d6d7d8, 0xd9dae1e2, 0xe3e4e5e6, 0xe7e8e9ea,
	0xf1f2f3f4, 0xf5f6f7f8, 0xf9fa0000
};

static const unsigned int hactbl_chr[HACTBL_SIZE] = {
	0x00020103, 0x03020403, 0x05050404, 0x0000017d, 0x01020300, 0x04110512,
	0x21314106, 0x13516107,	0x22711432, 0x8191a108, 0x2342b1c1, 0x1552d1f0,
	0x24336272, 0x82090a16, 0x1718191a, 0x25262728, 0x292a3435, 0x36373839,
	0x3a434445, 0x46474849, 0x4a535455, 0x56575859, 0x5a636465, 0x66676869,
	0x6a737475, 0x76777879, 0x7a838485, 0x86878889, 0x8a929394, 0x95969798,
	0x999aa2a3, 0xa4a5a6a7, 0xa8a9aab2, 0xb3b4b5b6, 0xb7b8b9ba, 0xc2c3c4c5,
	0xc6c7c8c9, 0xcad2d3d4, 0xd5d6d7d8, 0xd9dae1e2, 0xe3e4e5e6, 0xe7e8e9ea,
	0xf1f2f3f4, 0xf5f6f7f8, 0xf9fa0000
};

static const char *error_to_text[16] = {
	"Normal",
	"SOI not detected",
	"SOF1 to SOFF detected",
	"Subsampling not detected",
	"SOF accuracy error",
	"DQT accuracy error",
	"Component error 1",
	"Component error 2",
	"SOF0, DQT, and DHT not detected when SOS detected",
	"SOS not detected",
	"EOI not detected",
	"Restart interval data number error detected",
	"Image size error",
	"Last MCU data number error",
	"Block data number error",
	"Unknown"
};

static struct jpu_buffer *vb2_to_jpu_buffer(struct vb2_v4l2_buffer *vb)
{
	struct v4l2_m2m_buffer *b =
		container_of(vb, struct v4l2_m2m_buffer, vb);

	return container_of(b, struct jpu_buffer, buf);
}

static u32 jpu_read(struct jpu *jpu, unsigned int reg)
{
	return ioread32(jpu->regs + reg);
}

static void jpu_write(struct jpu *jpu, u32 val, unsigned int reg)
{
	iowrite32(val, jpu->regs + reg);
}

static struct jpu_ctx *ctrl_to_ctx(struct v4l2_ctrl *c)
{
	return container_of(c->handler, struct jpu_ctx, ctrl_handler);
}

static struct jpu_ctx *fh_to_ctx(struct v4l2_fh *fh)
{
	return container_of(fh, struct jpu_ctx, fh);
}

static void jpu_set_tbl(struct jpu *jpu, u32 reg, const unsigned int *tbl,
			unsigned int len) {
	unsigned int i;

	for (i = 0; i < len; i++)
		jpu_write(jpu, tbl[i], reg + (i << 2));
}

static void jpu_set_qtbl(struct jpu *jpu, unsigned short quality)
{
	jpu_set_tbl(jpu, JCQTBL(0), qtbl_lum[quality], QTBL_SIZE);
	jpu_set_tbl(jpu, JCQTBL(1), qtbl_chr[quality], QTBL_SIZE);
}

static void jpu_set_htbl(struct jpu *jpu)
{
	jpu_set_tbl(jpu, JCHTBD(0), hdctbl_lum, HDCTBL_SIZE);
	jpu_set_tbl(jpu, JCHTBA(0), hactbl_lum, HACTBL_SIZE);
	jpu_set_tbl(jpu, JCHTBD(1), hdctbl_chr, HDCTBL_SIZE);
	jpu_set_tbl(jpu, JCHTBA(1), hactbl_chr, HACTBL_SIZE);
}

static int jpu_wait_reset(struct jpu *jpu)
{
	unsigned long timeout;

	timeout = jiffies + msecs_to_jiffies(JPU_RESET_TIMEOUT);

	while (jpu_read(jpu, JCCMD) & JCCMD_SRST) {
		if (time_after(jiffies, timeout)) {
			dev_err(jpu->dev, "timed out in reset\n");
			return -ETIMEDOUT;
		}
		schedule();
	}

	return 0;
}

static int jpu_reset(struct jpu *jpu)
{
	jpu_write(jpu, JCCMD_SRST, JCCMD);
	return jpu_wait_reset(jpu);
}

/*
 * ============================================================================
 * video ioctl operations
 * ============================================================================
 */
static void put_qtbl(u8 *p, const u8 *qtbl)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(zigzag); i++)
		p[i] = *(qtbl + zigzag[i]);
}

static void put_htbl(u8 *p, const u8 *htbl, unsigned int len)
{
	unsigned int i, j;

	for (i = 0; i < len; i += 4)
		for (j = 0; j < 4 && (i + j) < len; ++j)
			p[i + j] = htbl[i + 3 - j];
}

static void jpu_generate_hdr(unsigned short quality, unsigned char *p)
{
	put_qtbl(p + JPU_JPEG_QTBL_LUM_OFFSET, (const u8 *)qtbl_lum[quality]);
	put_qtbl(p + JPU_JPEG_QTBL_CHR_OFFSET, (const u8 *)qtbl_chr[quality]);

	put_htbl(p + JPU_JPEG_HDCTBL_LUM_OFFSET, (const u8 *)hdctbl_lum,
		 JPU_JPEG_HDCTBL_SIZE);
	put_htbl(p + JPU_JPEG_HACTBL_LUM_OFFSET, (const u8 *)hactbl_lum,
		 JPU_JPEG_HACTBL_SIZE);

	put_htbl(p + JPU_JPEG_HDCTBL_CHR_OFFSET, (const u8 *)hdctbl_chr,
		 JPU_JPEG_HDCTBL_SIZE);
	put_htbl(p + JPU_JPEG_HACTBL_CHR_OFFSET, (const u8 *)hactbl_chr,
		 JPU_JPEG_HACTBL_SIZE);
}

static int get_byte(struct jpeg_buffer *buf)
{
	if (buf->curr >= buf->end)
		return -1;

	return *(u8 *)buf->curr++;
}

static int get_word_be(struct jpeg_buffer *buf, unsigned int *word)
{
	if (buf->end - buf->curr < 2)
		return -1;

	*word = get_unaligned_be16(buf->curr);
	buf->curr += 2;

	return 0;
}

static void skip(struct jpeg_buffer *buf, unsigned long len)
{
	buf->curr += min((unsigned long)(buf->end - buf->curr), len);
}

static u8 jpu_parse_hdr(void *buffer, unsigned long size, unsigned int *width,
			  unsigned int *height)
{
	struct jpeg_buffer jpeg_buffer;
	unsigned int word;
	bool soi = false;

	jpeg_buffer.end = buffer + size;
	jpeg_buffer.curr = buffer;

	/*
	 * basic size check and EOI - we don't want to let JPU cross
	 * buffer bounds in any case. Hope it's stopping by EOI.
	 */
	if (size < JPU_JPEG_MIN_SIZE || *(u8 *)(buffer + size - 1) != EOI)
		return 0;

	for (;;) {
		int c;

		/* skip preceding filler bytes */
		do
			c = get_byte(&jpeg_buffer);
		while (c == 0xff || c == 0);

		if (!soi && c == SOI) {
			soi = true;
			continue;
		} else if (soi != (c != SOI))
			return 0;

		switch (c) {
		case SOF0: /* SOF0: baseline JPEG */
			skip(&jpeg_buffer, 3); /* segment length and bpp */
			if (get_word_be(&jpeg_buffer, height) ||
			    get_word_be(&jpeg_buffer, width) ||
			    get_byte(&jpeg_buffer) != 3) /* YCbCr only */
				return 0;

			skip(&jpeg_buffer, 1);
			return get_byte(&jpeg_buffer);
		case DHT:
		case DQT:
		case COM:
		case DRI:
		case APP0 ... APP0 + 0x0f:
			if (get_word_be(&jpeg_buffer, &word))
				return 0;
			skip(&jpeg_buffer, (long)word - 2);
		case 0:
			break;
		default:
			return 0;
		}
	}

	return 0;
}

static int jpu_querycap(struct file *file, void *priv,
			struct v4l2_capability *cap)
{
	struct jpu_ctx *ctx = fh_to_ctx(priv);

	if (ctx->encoder)
		strlcpy(cap->card, DRV_NAME " encoder", sizeof(cap->card));
	else
		strlcpy(cap->card, DRV_NAME " decoder", sizeof(cap->card));

	strlcpy(cap->driver, DRV_NAME, sizeof(cap->driver));
	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
		 dev_name(ctx->jpu->dev));
	cap->device_caps |= V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_M2M_MPLANE;
	cap->capabilities = V4L2_CAP_DEVICE_CAPS | cap->device_caps;
	memset(cap->reserved, 0, sizeof(cap->reserved));

	return 0;
}

static struct jpu_fmt *jpu_find_format(bool encoder, u32 pixelformat,
				       unsigned int fmt_type)
{
	unsigned int i, fmt_flag;

	if (encoder)
		fmt_flag = fmt_type == JPU_FMT_TYPE_OUTPUT ? JPU_ENC_OUTPUT :
							     JPU_ENC_CAPTURE;
	else
		fmt_flag = fmt_type == JPU_FMT_TYPE_OUTPUT ? JPU_DEC_OUTPUT :
							     JPU_DEC_CAPTURE;

	for (i = 0; i < ARRAY_SIZE(jpu_formats); i++) {
		struct jpu_fmt *fmt = &jpu_formats[i];

		if (fmt->fourcc == pixelformat && fmt->types & fmt_flag)
			return fmt;
	}

	return NULL;
}

static int jpu_enum_fmt(struct v4l2_fmtdesc *f, u32 type)
{
	unsigned int i, num = 0;

	for (i = 0; i < ARRAY_SIZE(jpu_formats); ++i) {
		if (jpu_formats[i].types & type) {
			if (num == f->index)
				break;
			++num;
		}
	}

	if (i >= ARRAY_SIZE(jpu_formats))
		return -EINVAL;

	f->pixelformat = jpu_formats[i].fourcc;

	return 0;
}

static int jpu_enum_fmt_cap(struct file *file, void *priv,
			    struct v4l2_fmtdesc *f)
{
	struct jpu_ctx *ctx = fh_to_ctx(priv);

	return jpu_enum_fmt(f, ctx->encoder ? JPU_ENC_CAPTURE :
			    JPU_DEC_CAPTURE);
}

static int jpu_enum_fmt_out(struct file *file, void *priv,
			    struct v4l2_fmtdesc *f)
{
	struct jpu_ctx *ctx = fh_to_ctx(priv);

	return jpu_enum_fmt(f, ctx->encoder ? JPU_ENC_OUTPUT : JPU_DEC_OUTPUT);
}

static struct jpu_q_data *jpu_get_q_data(struct jpu_ctx *ctx,
					 enum v4l2_buf_type type)
{
	if (V4L2_TYPE_IS_OUTPUT(type))
		return &ctx->out_q;
	else
		return &ctx->cap_q;
}

static void jpu_bound_align_image(u32 *w, unsigned int w_min,
				  unsigned int w_max, unsigned int w_align,
				  u32 *h, unsigned int h_min,
				  unsigned int h_max, unsigned int h_align)
{
	unsigned int width, height, w_step, h_step;

	width = *w;
	height = *h;

	w_step = 1U << w_align;
	h_step = 1U << h_align;
	v4l_bound_align_image(w, w_min, w_max, w_align, h, h_min, h_max,
			      h_align, 3);

	if (*w < width && *w + w_step < w_max)
		*w += w_step;
	if (*h < height && *h + h_step < h_max)
		*h += h_step;
}

static int __jpu_try_fmt(struct jpu_ctx *ctx, struct jpu_fmt **fmtinfo,
			 struct v4l2_pix_format_mplane *pix,
			 enum v4l2_buf_type type)
{
	struct jpu_fmt *fmt;
	unsigned int f_type, w, h;

	f_type = V4L2_TYPE_IS_OUTPUT(type) ? JPU_FMT_TYPE_OUTPUT :
						JPU_FMT_TYPE_CAPTURE;

	fmt = jpu_find_format(ctx->encoder, pix->pixelformat, f_type);
	if (!fmt) {
		unsigned int pixelformat;

		dev_dbg(ctx->jpu->dev, "unknown format; set default format\n");
		if (ctx->encoder)
			pixelformat = f_type == JPU_FMT_TYPE_OUTPUT ?
				V4L2_PIX_FMT_NV16M : V4L2_PIX_FMT_JPEG;
		else
			pixelformat = f_type == JPU_FMT_TYPE_CAPTURE ?
				V4L2_PIX_FMT_NV16M : V4L2_PIX_FMT_JPEG;
		fmt = jpu_find_format(ctx->encoder, pixelformat, f_type);
	}

	pix->pixelformat = fmt->fourcc;
	pix->colorspace = fmt->colorspace;
	pix->field = V4L2_FIELD_NONE;
	pix->num_planes = fmt->num_planes;
	memset(pix->reserved, 0, sizeof(pix->reserved));

	jpu_bound_align_image(&pix->width, JPU_WIDTH_MIN, JPU_WIDTH_MAX,
			      fmt->h_align, &pix->height, JPU_HEIGHT_MIN,
			      JPU_HEIGHT_MAX, fmt->v_align);

	w = pix->width;
	h = pix->height;

	if (fmt->fourcc == V4L2_PIX_FMT_JPEG) {
		/* ignore userspaces's sizeimage for encoding */
		if (pix->plane_fmt[0].sizeimage <= 0 || ctx->encoder)
			pix->plane_fmt[0].sizeimage = JPU_JPEG_HDR_SIZE +
				(JPU_JPEG_MAX_BYTES_PER_PIXEL * w * h);
		pix->plane_fmt[0].bytesperline = 0;
		memset(pix->plane_fmt[0].reserved, 0,
		       sizeof(pix->plane_fmt[0].reserved));
	} else {
		unsigned int i, bpl = 0;

		for (i = 0; i < pix->num_planes; ++i)
			bpl = max(bpl, pix->plane_fmt[i].bytesperline);

		bpl = clamp_t(unsigned int, bpl, w, JPU_WIDTH_MAX);
		bpl = round_up(bpl, JPU_MEMALIGN);

		for (i = 0; i < pix->num_planes; ++i) {
			pix->plane_fmt[i].bytesperline = bpl;
			pix->plane_fmt[i].sizeimage = bpl * h * fmt->bpp[i] / 8;
			memset(pix->plane_fmt[i].reserved, 0,
			       sizeof(pix->plane_fmt[i].reserved));
		}
	}

	if (fmtinfo)
		*fmtinfo = fmt;

	return 0;
}

static int jpu_try_fmt(struct file *file, void *priv, struct v4l2_format *f)
{
	struct jpu_ctx *ctx = fh_to_ctx(priv);

	if (!v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type))
		return -EINVAL;

	return __jpu_try_fmt(ctx, NULL, &f->fmt.pix_mp, f->type);
}

static int jpu_s_fmt(struct file *file, void *priv, struct v4l2_format *f)
{
	struct vb2_queue *vq;
	struct jpu_ctx *ctx = fh_to_ctx(priv);
	struct v4l2_m2m_ctx *m2m_ctx = ctx->fh.m2m_ctx;
	struct jpu_fmt *fmtinfo;
	struct jpu_q_data *q_data;
	int ret;

	vq = v4l2_m2m_get_vq(m2m_ctx, f->type);
	if (!vq)
		return -EINVAL;

	if (vb2_is_busy(vq)) {
		v4l2_err(&ctx->jpu->v4l2_dev, "%s queue busy\n", __func__);
		return -EBUSY;
	}

	ret = __jpu_try_fmt(ctx, &fmtinfo, &f->fmt.pix_mp, f->type);
	if (ret < 0)
		return ret;

	q_data = jpu_get_q_data(ctx, f->type);

	q_data->format = f->fmt.pix_mp;
	q_data->fmtinfo = fmtinfo;

	return 0;
}

static int jpu_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
{
	struct jpu_q_data *q_data;
	struct jpu_ctx *ctx = fh_to_ctx(priv);

	if (!v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type))
		return -EINVAL;

	q_data = jpu_get_q_data(ctx, f->type);
	f->fmt.pix_mp = q_data->format;

	return 0;
}

/*
 * V4L2 controls
 */
static int jpu_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct jpu_ctx *ctx = ctrl_to_ctx(ctrl);
	unsigned long flags;

	spin_lock_irqsave(&ctx->jpu->lock, flags);
	if (ctrl->id == V4L2_CID_JPEG_COMPRESSION_QUALITY)
		ctx->compr_quality = ctrl->val;
	spin_unlock_irqrestore(&ctx->jpu->lock, flags);

	return 0;
}

static const struct v4l2_ctrl_ops jpu_ctrl_ops = {
	.s_ctrl		= jpu_s_ctrl,
};

static int jpu_streamon(struct file *file, void *priv, enum v4l2_buf_type type)
{
	struct jpu_ctx *ctx = fh_to_ctx(priv);
	struct jpu_q_data *src_q_data, *dst_q_data, *orig, adj, *ref;
	enum v4l2_buf_type adj_type;

	src_q_data = jpu_get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
	dst_q_data = jpu_get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);

	if (ctx->encoder) {
		adj = *src_q_data;
		orig = src_q_data;
		ref = dst_q_data;
		adj_type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
	} else {
		adj = *dst_q_data;
		orig = dst_q_data;
		ref = src_q_data;
		adj_type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
	}

	adj.format.width = ref->format.width;
	adj.format.height = ref->format.height;

	__jpu_try_fmt(ctx, NULL, &adj.format, adj_type);

	if (adj.format.width != orig->format.width ||
	    adj.format.height != orig->format.height) {
		dev_err(ctx->jpu->dev, "src and dst formats do not match.\n");
		/* maybe we can return -EPIPE here? */
		return -EINVAL;
	}

	return v4l2_m2m_streamon(file, ctx->fh.m2m_ctx, type);
}

static const struct v4l2_ioctl_ops jpu_ioctl_ops = {
	.vidioc_querycap		= jpu_querycap,

	.vidioc_enum_fmt_vid_cap_mplane = jpu_enum_fmt_cap,
	.vidioc_enum_fmt_vid_out_mplane = jpu_enum_fmt_out,
	.vidioc_g_fmt_vid_cap_mplane	= jpu_g_fmt,
	.vidioc_g_fmt_vid_out_mplane	= jpu_g_fmt,
	.vidioc_try_fmt_vid_cap_mplane	= jpu_try_fmt,
	.vidioc_try_fmt_vid_out_mplane	= jpu_try_fmt,
	.vidioc_s_fmt_vid_cap_mplane	= jpu_s_fmt,
	.vidioc_s_fmt_vid_out_mplane	= jpu_s_fmt,

	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
	.vidioc_create_bufs             = v4l2_m2m_ioctl_create_bufs,
	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
	.vidioc_qbuf			= v4l2_m2m_ioctl_qbuf,
	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
#endif

	.vidioc_streamon		= jpu_streamon,
	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,

	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe
};

static int jpu_controls_create(struct jpu_ctx *ctx)
{
	struct v4l2_ctrl *ctrl;
	int ret;

	v4l2_ctrl_handler_init(&ctx->ctrl_handler, 1);

	ctrl = v4l2_ctrl_new_std(&ctx->ctrl_handler, &jpu_ctrl_ops,
				 V4L2_CID_JPEG_COMPRESSION_QUALITY,
				 0, JPU_MAX_QUALITY - 1, 1, 0);

	if (ctx->ctrl_handler.error) {
		ret = ctx->ctrl_handler.error;
		goto error_free;
	}

	if (!ctx->encoder)
		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE |
				V4L2_CTRL_FLAG_READ_ONLY;

	ret = v4l2_ctrl_handler_setup(&ctx->ctrl_handler);
	if (ret < 0)
		goto error_free;

	return 0;

error_free:
	v4l2_ctrl_handler_free(&ctx->ctrl_handler);
	return ret;
}

/*
 * ============================================================================
 * Queue operations
 * ============================================================================
 */
static int jpu_queue_setup(struct vb2_queue *vq,
			   unsigned int *nbuffers, unsigned int *nplanes,
			   unsigned int sizes[], void *alloc_ctxs[])
{
	struct jpu_ctx *ctx = vb2_get_drv_priv(vq);
	struct jpu_q_data *q_data;
	unsigned int i;

	q_data = jpu_get_q_data(ctx, vq->type);

	if (*nplanes) {
		if (*nplanes != q_data->format.num_planes)
			return -EINVAL;

		for (i = 0; i < *nplanes; i++) {
			unsigned int q_size = q_data->format.plane_fmt[i].sizeimage;

			if (sizes[i] < q_size)
				return -EINVAL;
			alloc_ctxs[i] = ctx->jpu->alloc_ctx;
		}
		return 0;
	}

	*nplanes = q_data->format.num_planes;

	for (i = 0; i < *nplanes; i++) {
		sizes[i] = q_data->format.plane_fmt[i].sizeimage;
		alloc_ctxs[i] = ctx->jpu->alloc_ctx;
	}

	return 0;
}

static int jpu_buf_prepare(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct jpu_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
	struct jpu_q_data *q_data;
	unsigned int i;

	q_data = jpu_get_q_data(ctx, vb->vb2_queue->type);

	if (V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type)) {
		if (vbuf->field == V4L2_FIELD_ANY)
			vbuf->field = V4L2_FIELD_NONE;
		if (vbuf->field != V4L2_FIELD_NONE) {
			dev_err(ctx->jpu->dev, "%s field isn't supported\n",
					__func__);
			return -EINVAL;
		}
	}

	for (i = 0; i < q_data->format.num_planes; i++) {
		unsigned long size = q_data->format.plane_fmt[i].sizeimage;

		if (vb2_plane_size(vb, i) < size) {
			dev_err(ctx->jpu->dev,
				"%s: data will not fit into plane (%lu < %lu)\n",
			       __func__, vb2_plane_size(vb, i), size);
			return -EINVAL;
		}

		/* decoder capture queue */
		if (!ctx->encoder && !V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
			vb2_set_plane_payload(vb, i, size);
	}

	return 0;
}

static void jpu_buf_queue(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct jpu_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);

	if (!ctx->encoder && V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type)) {
		struct jpu_buffer *jpu_buf = vb2_to_jpu_buffer(vbuf);
		struct jpu_q_data *q_data, adjust;
		void *buffer = vb2_plane_vaddr(vb, 0);
		unsigned long buf_size = vb2_get_plane_payload(vb, 0);
		unsigned int width, height;

		u8 subsampling = jpu_parse_hdr(buffer, buf_size, &width,
						 &height);

		/* check if JPEG data basic parsing was successful */
		if (subsampling != JPU_JPEG_422 && subsampling != JPU_JPEG_420)
			goto format_error;

		q_data = &ctx->out_q;

		adjust = *q_data;
		adjust.format.width = width;
		adjust.format.height = height;

		__jpu_try_fmt(ctx, &adjust.fmtinfo, &adjust.format,
			      V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);

		if (adjust.format.width != q_data->format.width ||
		    adjust.format.height != q_data->format.height)
			goto format_error;

		/*
		 * keep subsampling in buffer to check it
		 * for compatibility in device_run
		 */
		jpu_buf->subsampling = subsampling;
	}

	if (ctx->fh.m2m_ctx)
		v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);

	return;

format_error:
	dev_err(ctx->jpu->dev, "incompatible or corrupted JPEG data\n");
	vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
}

static void jpu_buf_finish(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct jpu_buffer *jpu_buf = vb2_to_jpu_buffer(vbuf);
	struct jpu_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
	struct jpu_q_data *q_data = &ctx->out_q;
	enum v4l2_buf_type type = vb->vb2_queue->type;
	u8 *buffer;

	if (vb->state == VB2_BUF_STATE_DONE)
		vbuf->sequence = jpu_get_q_data(ctx, type)->sequence++;

	if (!ctx->encoder || vb->state != VB2_BUF_STATE_DONE ||
	    V4L2_TYPE_IS_OUTPUT(type))
		return;

	buffer = vb2_plane_vaddr(vb, 0);

	memcpy(buffer, jpeg_hdrs[jpu_buf->compr_quality], JPU_JPEG_HDR_SIZE);
	*(__be16 *)(buffer + JPU_JPEG_HEIGHT_OFFSET) =
					cpu_to_be16(q_data->format.height);
	*(__be16 *)(buffer + JPU_JPEG_WIDTH_OFFSET) =
					cpu_to_be16(q_data->format.width);
	*(buffer + JPU_JPEG_SUBS_OFFSET) = q_data->fmtinfo->subsampling;
}

static int jpu_start_streaming(struct vb2_queue *vq, unsigned count)
{
	struct jpu_ctx *ctx = vb2_get_drv_priv(vq);
	struct jpu_q_data *q_data = jpu_get_q_data(ctx, vq->type);

	q_data->sequence = 0;
	return 0;
}

static void jpu_stop_streaming(struct vb2_queue *vq)
{
	struct jpu_ctx *ctx = vb2_get_drv_priv(vq);
	struct vb2_v4l2_buffer *vb;
	unsigned long flags;

	for (;;) {
		if (V4L2_TYPE_IS_OUTPUT(vq->type))
			vb = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
		else
			vb = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
		if (vb == NULL)
			return;
		spin_lock_irqsave(&ctx->jpu->lock, flags);
		v4l2_m2m_buf_done(vb, VB2_BUF_STATE_ERROR);
		spin_unlock_irqrestore(&ctx->jpu->lock, flags);
	}
}

static struct vb2_ops jpu_qops = {
	.queue_setup		= jpu_queue_setup,
	.buf_prepare		= jpu_buf_prepare,
	.buf_queue		= jpu_buf_queue,
	.buf_finish		= jpu_buf_finish,
	.start_streaming	= jpu_start_streaming,
	.stop_streaming		= jpu_stop_streaming,
	.wait_prepare		= vb2_ops_wait_prepare,
	.wait_finish		= vb2_ops_wait_finish,
};

static int jpu_queue_init(void *priv, struct vb2_queue *src_vq,
			  struct vb2_queue *dst_vq)
{
	struct jpu_ctx *ctx = priv;
	int ret;

	memset(src_vq, 0, sizeof(*src_vq));
	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	src_vq->drv_priv = ctx;
	src_vq->buf_struct_size = sizeof(struct jpu_buffer);
	src_vq->ops = &jpu_qops;
	src_vq->mem_ops = &vb2_dma_contig_memops;
	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	src_vq->lock = &ctx->jpu->mutex;

	ret = vb2_queue_init(src_vq);
	if (ret)
		return ret;

	memset(dst_vq, 0, sizeof(*dst_vq));
	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	dst_vq->drv_priv = ctx;
	dst_vq->buf_struct_size = sizeof(struct jpu_buffer);
	dst_vq->ops = &jpu_qops;
	dst_vq->mem_ops = &vb2_dma_contig_memops;
	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	dst_vq->lock = &ctx->jpu->mutex;

	return vb2_queue_init(dst_vq);
}

/*
 * ============================================================================
 * Device file operations
 * ============================================================================
 */
static int jpu_open(struct file *file)
{
	struct jpu *jpu = video_drvdata(file);
	struct video_device *vfd = video_devdata(file);
	struct jpu_ctx *ctx;
	int ret;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	v4l2_fh_init(&ctx->fh, vfd);
	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
	file->private_data = &ctx->fh;
	v4l2_fh_add(&ctx->fh);

	ctx->jpu = jpu;
	ctx->encoder = vfd == &jpu->vfd_encoder;

	__jpu_try_fmt(ctx, &ctx->out_q.fmtinfo, &ctx->out_q.format,
		      V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
	__jpu_try_fmt(ctx, &ctx->cap_q.fmtinfo, &ctx->cap_q.format,
		      V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);

	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(jpu->m2m_dev, ctx, jpu_queue_init);
	if (IS_ERR(ctx->fh.m2m_ctx)) {
		ret = PTR_ERR(ctx->fh.m2m_ctx);
		goto v4l_prepare_rollback;
	}

	ret = jpu_controls_create(ctx);
	if (ret < 0)
		goto v4l_prepare_rollback;

	if (mutex_lock_interruptible(&jpu->mutex)) {
		ret = -ERESTARTSYS;
		goto v4l_prepare_rollback;
	}

	if (jpu->ref_count == 0) {
		ret = clk_prepare_enable(jpu->clk);
		if (ret < 0)
			goto device_prepare_rollback;
		/* ...issue software reset */
		ret = jpu_reset(jpu);
		if (ret)
			goto device_prepare_rollback;
	}

	jpu->ref_count++;

	mutex_unlock(&jpu->mutex);
	return 0;

device_prepare_rollback:
	mutex_unlock(&jpu->mutex);
v4l_prepare_rollback:
	v4l2_fh_del(&ctx->fh);
	v4l2_fh_exit(&ctx->fh);
	kfree(ctx);
	return ret;
}

static int jpu_release(struct file *file)
{
	struct jpu *jpu = video_drvdata(file);
	struct jpu_ctx *ctx = fh_to_ctx(file->private_data);

	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
	v4l2_ctrl_handler_free(&ctx->ctrl_handler);
	v4l2_fh_del(&ctx->fh);
	v4l2_fh_exit(&ctx->fh);
	kfree(ctx);

	mutex_lock(&jpu->mutex);
	if (--jpu->ref_count == 0)
		clk_disable_unprepare(jpu->clk);
	mutex_unlock(&jpu->mutex);

	return 0;
}

static const struct v4l2_file_operations jpu_fops = {
	.owner		= THIS_MODULE,
	.open		= jpu_open,
	.release	= jpu_release,
	.unlocked_ioctl	= video_ioctl2,
	.poll		= v4l2_m2m_fop_poll,
	.mmap		= v4l2_m2m_fop_mmap,
};

/*
 * ============================================================================
 * mem2mem callbacks
 * ============================================================================
 */
static void jpu_cleanup(struct jpu_ctx *ctx, bool reset)
{
	/* remove current buffers and finish job */
	struct vb2_v4l2_buffer *src_buf, *dst_buf;
	unsigned long flags;

	spin_lock_irqsave(&ctx->jpu->lock, flags);

	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);

	v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
	v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);

	/* ...and give it a chance on next run */
	if (reset)
		jpu_write(ctx->jpu, JCCMD_SRST, JCCMD);

	spin_unlock_irqrestore(&ctx->jpu->lock, flags);

	v4l2_m2m_job_finish(ctx->jpu->m2m_dev, ctx->fh.m2m_ctx);
}

static void jpu_device_run(void *priv)
{
	struct jpu_ctx *ctx = priv;
	struct jpu *jpu = ctx->jpu;
	struct jpu_buffer *jpu_buf;
	struct jpu_q_data *q_data;
	struct vb2_v4l2_buffer *src_buf, *dst_buf;
	unsigned int w, h, bpl;
	unsigned char num_planes, subsampling;
	unsigned long flags;

	/* ...wait until module reset completes; we have mutex locked here */
	if (jpu_wait_reset(jpu)) {
		jpu_cleanup(ctx, true);
		return;
	}

	spin_lock_irqsave(&ctx->jpu->lock, flags);

	jpu->curr = ctx;

	src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
	dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);

	if (ctx->encoder) {
		jpu_buf = vb2_to_jpu_buffer(dst_buf);
		q_data = &ctx->out_q;
	} else {
		jpu_buf = vb2_to_jpu_buffer(src_buf);
		q_data = &ctx->cap_q;
	}

	w = q_data->format.width;
	h = q_data->format.height;
	bpl = q_data->format.plane_fmt[0].bytesperline;
	num_planes = q_data->fmtinfo->num_planes;
	subsampling = q_data->fmtinfo->subsampling;

	if (ctx->encoder) {
		unsigned long src_1_addr, src_2_addr, dst_addr;
		unsigned int redu, inft;

		dst_addr = vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0);
		src_1_addr =
			vb2_dma_contig_plane_dma_addr(&src_buf->vb2_buf, 0);
		if (num_planes > 1)
			src_2_addr = vb2_dma_contig_plane_dma_addr(
					&src_buf->vb2_buf, 1);
		else
			src_2_addr = src_1_addr + w * h;

		jpu_buf->compr_quality = ctx->compr_quality;

		if (subsampling == JPU_JPEG_420) {
			redu = JCMOD_REDU_420;
			inft = JIFECNT_INFT_420;
		} else {
			redu = JCMOD_REDU_422;
			inft = JIFECNT_INFT_422;
		}

		/* only no marker mode works for encoding */
		jpu_write(jpu, JCMOD_DSP_ENC | JCMOD_PCTR | redu |
			  JCMOD_MSKIP_ENABLE, JCMOD);

		jpu_write(jpu, JIFECNT_SWAP_WB | inft, JIFECNT);
		jpu_write(jpu, JIFDCNT_SWAP_WB, JIFDCNT);
		jpu_write(jpu, JINTE_TRANSF_COMPL, JINTE);

		/* Y and C components source addresses */
		jpu_write(jpu, src_1_addr, JIFESYA1);
		jpu_write(jpu, src_2_addr, JIFESCA1);

		/* memory width */
		jpu_write(jpu, bpl, JIFESMW);

		jpu_write(jpu, (w >> 8) & JCSZ_MASK, JCHSZU);
		jpu_write(jpu, w & JCSZ_MASK, JCHSZD);

		jpu_write(jpu, (h >> 8) & JCSZ_MASK, JCVSZU);
		jpu_write(jpu, h & JCSZ_MASK, JCVSZD);

		jpu_write(jpu, w, JIFESHSZ);
		jpu_write(jpu, h, JIFESVSZ);

		jpu_write(jpu, dst_addr + JPU_JPEG_HDR_SIZE, JIFEDA1);

		jpu_write(jpu, 0 << JCQTN_SHIFT(1) | 1 << JCQTN_SHIFT(2) |
			  1 << JCQTN_SHIFT(3), JCQTN);

		jpu_write(jpu, 0 << JCHTN_AC_SHIFT(1) | 0 << JCHTN_DC_SHIFT(1) |
			  1 << JCHTN_AC_SHIFT(2) | 1 << JCHTN_DC_SHIFT(2) |
			  1 << JCHTN_AC_SHIFT(3) | 1 << JCHTN_DC_SHIFT(3),
			  JCHTN);

		jpu_set_qtbl(jpu, ctx->compr_quality);
		jpu_set_htbl(jpu);
	} else {
		unsigned long src_addr, dst_1_addr, dst_2_addr;

		if (jpu_buf->subsampling != subsampling) {
			dev_err(ctx->jpu->dev,
				"src and dst formats do not match.\n");
			spin_unlock_irqrestore(&ctx->jpu->lock, flags);
			jpu_cleanup(ctx, false);
			return;
		}

		src_addr = vb2_dma_contig_plane_dma_addr(&src_buf->vb2_buf, 0);
		dst_1_addr =
			vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0);
		if (q_data->fmtinfo->num_planes > 1)
			dst_2_addr = vb2_dma_contig_plane_dma_addr(
					&dst_buf->vb2_buf, 1);
		else
			dst_2_addr = dst_1_addr + w * h;

		/* ...set up decoder operation */
		jpu_write(jpu, JCMOD_DSP_DEC | JCMOD_PCTR, JCMOD);
		jpu_write(jpu, JIFECNT_SWAP_WB, JIFECNT);
		jpu_write(jpu, JIFDCNT_SWAP_WB, JIFDCNT);

		/* ...enable interrupts on transfer completion and d-g error */
		jpu_write(jpu, JINTE_TRANSF_COMPL | JINTE_ERR, JINTE);

		/* ...set source/destination addresses of encoded data */
		jpu_write(jpu, src_addr, JIFDSA1);
		jpu_write(jpu, dst_1_addr, JIFDDYA1);
		jpu_write(jpu, dst_2_addr, JIFDDCA1);

		jpu_write(jpu, bpl, JIFDDMW);
	}

	/* ...start encoder/decoder operation */
	jpu_write(jpu, JCCMD_JSRT, JCCMD);

	spin_unlock_irqrestore(&ctx->jpu->lock, flags);
}

static int jpu_job_ready(void *priv)
{
	return 1;
}

static void jpu_job_abort(void *priv)
{
	struct jpu_ctx *ctx = priv;

	if (!wait_event_timeout(ctx->jpu->irq_queue, !ctx->jpu->curr,
				msecs_to_jiffies(JPU_JOB_TIMEOUT)))
		jpu_cleanup(ctx, true);
}

static struct v4l2_m2m_ops jpu_m2m_ops = {
	.device_run	= jpu_device_run,
	.job_ready	= jpu_job_ready,
	.job_abort	= jpu_job_abort,
};

/*
 * ============================================================================
 * IRQ handler
 * ============================================================================
 */
static irqreturn_t jpu_irq_handler(int irq, void *dev_id)
{
	struct jpu *jpu = dev_id;
	struct jpu_ctx *curr_ctx;
	struct vb2_v4l2_buffer *src_buf, *dst_buf;
	unsigned int int_status;

	int_status = jpu_read(jpu, JINTS);

	/* ...spurious interrupt */
	if (!((JINTS_TRANSF_COMPL | JINTS_PROCESS_COMPL | JINTS_ERR) &
	    int_status))
		return IRQ_NONE;

	/* ...clear interrupts */
	jpu_write(jpu, ~(int_status & JINTS_MASK), JINTS);
	if (int_status & (JINTS_ERR | JINTS_PROCESS_COMPL))
		jpu_write(jpu, JCCMD_JEND, JCCMD);

	spin_lock(&jpu->lock);

	if ((int_status & JINTS_PROCESS_COMPL) &&
	   !(int_status & JINTS_TRANSF_COMPL))
		goto handled;

	curr_ctx = v4l2_m2m_get_curr_priv(jpu->m2m_dev);
	if (!curr_ctx) {
		/* ...instance is not running */
		dev_err(jpu->dev, "no active context for m2m\n");
		goto handled;
	}

	src_buf = v4l2_m2m_src_buf_remove(curr_ctx->fh.m2m_ctx);
	dst_buf = v4l2_m2m_dst_buf_remove(curr_ctx->fh.m2m_ctx);

	if (int_status & JINTS_TRANSF_COMPL) {
		if (curr_ctx->encoder) {
			unsigned long payload_size = jpu_read(jpu, JCDTCU) << 16
						   | jpu_read(jpu, JCDTCM) << 8
						   | jpu_read(jpu, JCDTCD);
			vb2_set_plane_payload(&dst_buf->vb2_buf, 0,
				payload_size + JPU_JPEG_HDR_SIZE);
		}

		dst_buf->field = src_buf->field;
		dst_buf->vb2_buf.timestamp = src_buf->vb2_buf.timestamp;
		if (src_buf->flags & V4L2_BUF_FLAG_TIMECODE)
			dst_buf->timecode = src_buf->timecode;
		dst_buf->flags = src_buf->flags &
			(V4L2_BUF_FLAG_TIMECODE | V4L2_BUF_FLAG_KEYFRAME |
			 V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME |
			 V4L2_BUF_FLAG_TSTAMP_SRC_MASK);

		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_DONE);
		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_DONE);
	} else if (int_status & JINTS_ERR) {
		unsigned char error = jpu_read(jpu, JCDERR) & JCDERR_MASK;

		dev_dbg(jpu->dev, "processing error: %#X: %s\n", error,
			error_to_text[error]);

		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
		v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);
	}

	jpu->curr = NULL;

	/* ...reset JPU after completion */
	jpu_write(jpu, JCCMD_SRST, JCCMD);
	spin_unlock(&jpu->lock);

	v4l2_m2m_job_finish(jpu->m2m_dev, curr_ctx->fh.m2m_ctx);

	/* ...wakeup abort routine if needed */
	wake_up(&jpu->irq_queue);

	return IRQ_HANDLED;

handled:
	spin_unlock(&jpu->lock);
	return IRQ_HANDLED;
}

/*
 * ============================================================================
 * Driver basic infrastructure
 * ============================================================================
 */
static const struct of_device_id jpu_dt_ids[] = {
	{ .compatible = "renesas,jpu-r8a7790" }, /* H2 */
	{ .compatible = "renesas,jpu-r8a7791" }, /* M2-W */
	{ .compatible = "renesas,jpu-r8a7792" }, /* V2H */
	{ .compatible = "renesas,jpu-r8a7793" }, /* M2-N */
	{ },
};
MODULE_DEVICE_TABLE(of, jpu_dt_ids);

static int jpu_probe(struct platform_device *pdev)
{
	struct jpu *jpu;
	struct resource *res;
	int ret;
	unsigned int i;

	jpu = devm_kzalloc(&pdev->dev, sizeof(*jpu), GFP_KERNEL);
	if (!jpu)
		return -ENOMEM;

	init_waitqueue_head(&jpu->irq_queue);
	mutex_init(&jpu->mutex);
	spin_lock_init(&jpu->lock);
	jpu->dev = &pdev->dev;

	/* memory-mapped registers */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	jpu->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(jpu->regs))
		return PTR_ERR(jpu->regs);

	/* interrupt service routine registration */
	jpu->irq = ret = platform_get_irq(pdev, 0);
	if (ret < 0) {
		dev_err(&pdev->dev, "cannot find IRQ\n");
		return ret;
	}

	ret = devm_request_irq(&pdev->dev, jpu->irq, jpu_irq_handler, 0,
			       dev_name(&pdev->dev), jpu);
	if (ret) {
		dev_err(&pdev->dev, "cannot claim IRQ %d\n", jpu->irq);
		return ret;
	}

	/* clocks */
	jpu->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(jpu->clk)) {
		dev_err(&pdev->dev, "cannot get clock\n");
		return PTR_ERR(jpu->clk);
	}

	/* v4l2 device */
	ret = v4l2_device_register(&pdev->dev, &jpu->v4l2_dev);
	if (ret) {
		dev_err(&pdev->dev, "Failed to register v4l2 device\n");
		return ret;
	}

	/* mem2mem device */
	jpu->m2m_dev = v4l2_m2m_init(&jpu_m2m_ops);
	if (IS_ERR(jpu->m2m_dev)) {
		v4l2_err(&jpu->v4l2_dev, "Failed to init mem2mem device\n");
		ret = PTR_ERR(jpu->m2m_dev);
		goto device_register_rollback;
	}

	jpu->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
	if (IS_ERR(jpu->alloc_ctx)) {
		v4l2_err(&jpu->v4l2_dev, "Failed to init memory allocator\n");
		ret = PTR_ERR(jpu->alloc_ctx);
		goto m2m_init_rollback;
	}

	/* fill in qantization and Huffman tables for encoder */
	for (i = 0; i < JPU_MAX_QUALITY; i++)
		jpu_generate_hdr(i, (unsigned char *)jpeg_hdrs[i]);

	strlcpy(jpu->vfd_encoder.name, DRV_NAME, sizeof(jpu->vfd_encoder.name));
	jpu->vfd_encoder.fops		= &jpu_fops;
	jpu->vfd_encoder.ioctl_ops	= &jpu_ioctl_ops;
	jpu->vfd_encoder.minor		= -1;
	jpu->vfd_encoder.release	= video_device_release_empty;
	jpu->vfd_encoder.lock		= &jpu->mutex;
	jpu->vfd_encoder.v4l2_dev	= &jpu->v4l2_dev;
	jpu->vfd_encoder.vfl_dir	= VFL_DIR_M2M;

	ret = video_register_device(&jpu->vfd_encoder, VFL_TYPE_GRABBER, -1);
	if (ret) {
		v4l2_err(&jpu->v4l2_dev, "Failed to register video device\n");
		goto vb2_allocator_rollback;
	}

	video_set_drvdata(&jpu->vfd_encoder, jpu);

	strlcpy(jpu->vfd_decoder.name, DRV_NAME, sizeof(jpu->vfd_decoder.name));
	jpu->vfd_decoder.fops		= &jpu_fops;
	jpu->vfd_decoder.ioctl_ops	= &jpu_ioctl_ops;
	jpu->vfd_decoder.minor		= -1;
	jpu->vfd_decoder.release	= video_device_release_empty;
	jpu->vfd_decoder.lock		= &jpu->mutex;
	jpu->vfd_decoder.v4l2_dev	= &jpu->v4l2_dev;
	jpu->vfd_decoder.vfl_dir	= VFL_DIR_M2M;

	ret = video_register_device(&jpu->vfd_decoder, VFL_TYPE_GRABBER, -1);
	if (ret) {
		v4l2_err(&jpu->v4l2_dev, "Failed to register video device\n");
		goto enc_vdev_register_rollback;
	}

	video_set_drvdata(&jpu->vfd_decoder, jpu);
	platform_set_drvdata(pdev, jpu);

	v4l2_info(&jpu->v4l2_dev, "encoder device registered as /dev/video%d\n",
		  jpu->vfd_encoder.num);
	v4l2_info(&jpu->v4l2_dev, "decoder device registered as /dev/video%d\n",
		  jpu->vfd_decoder.num);

	return 0;

enc_vdev_register_rollback:
	video_unregister_device(&jpu->vfd_encoder);

vb2_allocator_rollback:
	vb2_dma_contig_cleanup_ctx(jpu->alloc_ctx);

m2m_init_rollback:
	v4l2_m2m_release(jpu->m2m_dev);

device_register_rollback:
	v4l2_device_unregister(&jpu->v4l2_dev);

	return ret;
}

static int jpu_remove(struct platform_device *pdev)
{
	struct jpu *jpu = platform_get_drvdata(pdev);

	video_unregister_device(&jpu->vfd_decoder);
	video_unregister_device(&jpu->vfd_encoder);
	vb2_dma_contig_cleanup_ctx(jpu->alloc_ctx);
	v4l2_m2m_release(jpu->m2m_dev);
	v4l2_device_unregister(&jpu->v4l2_dev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int jpu_suspend(struct device *dev)
{
	struct jpu *jpu = dev_get_drvdata(dev);

	if (jpu->ref_count == 0)
		return 0;

	clk_disable_unprepare(jpu->clk);

	return 0;
}

static int jpu_resume(struct device *dev)
{
	struct jpu *jpu = dev_get_drvdata(dev);

	if (jpu->ref_count == 0)
		return 0;

	clk_prepare_enable(jpu->clk);

	return 0;
}
#endif

static const struct dev_pm_ops jpu_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(jpu_suspend, jpu_resume)
};

static struct platform_driver jpu_driver = {
	.probe = jpu_probe,
	.remove = jpu_remove,
	.driver = {
		.of_match_table = jpu_dt_ids,
		.name = DRV_NAME,
		.pm = &jpu_pm_ops,
	},
};

module_platform_driver(jpu_driver);

MODULE_ALIAS("platform:" DRV_NAME);
MODULE_AUTHOR("Mikhail Ulianov <mikhail.ulyanov@cogentembedded.com>");
MODULE_DESCRIPTION("Renesas R-Car JPEG processing unit driver");
MODULE_LICENSE("GPL v2");