自己写coms_ov7740驱动

/* 作者：[e-mail] * 该驱动函数是基于linux3.4.2 * 该驱动程序是参考自己写的uvc驱动 * */cmos_ov7740_dev.c#include <linux kernel="" h="">#include <linux module="" h="">#include <linux platform_device="" h="">#include <linux i2c="" h="">#include <linux err="" h="">#include <linux regmap="" h="">#include <linux slab="" h="">/* 第一个参数名字用于匹配，第二个参数是摄像头地址 */static struct i2c_board_info cmos_ov7740_info = {/* 由芯片手册可知，写 -- 0x42(01000010)，读 -- 0x43(01000011) * 将读地址或者写地址，向右移动一位即可。 */I2C_BOARD_INFO("cmos_ov7740", 0x21),};static struct i2c_client *cmos_ov7740_client;static int cmos_ov7740_dev_init(void){struct i2c_adapter *i2c_adap;/* 获得适配器，由2440原理图可知，2440只有一个iic控制器，所以iic控制器为适配器0， * 也就是0号iic总线上 */i2c_adap = i2c_get_adapter(0);cmos_ov7740_client = i2c_new_device(i2c_adap, &cmos_ov7740_info);/* 适配器使用完后要释放他 */i2c_put_adapter(i2c_adap);return 0;}static void cmos_ov7740_dev_exit(void){i2c_unregister_device(cmos_ov7740_client);}module_init(cmos_ov7740_dev_init);module_exit(cmos_ov7740_dev_exit);MODULE_LICENSE("GPL");cmos_ov7740_drv.c</linux></linux></linux></linux></linux></linux></linux>/* 该驱动函数是基于linux3.4.2 * 该驱动程序是参考自己写的uvc驱动 * */#include <linux kernel="" h="">#include <linux module="" h="">#include <linux platform_device="" h="">#include <linux i2c="" h="">#include <linux err="" h="">#include <linux regmap="" h="">#include <linux slab="" h="">#include <linux kernel="" h="">#include <linux list="" h="">#include <linux module="" h="">#include <linux usb="" h="">#include <linux videodev2="" h="">#include <linux vmalloc="" h="">#include <linux wait="" h="">#include <linux mm="" h="">#include #include #include <media v4l2-common="" h="">#include <media v4l2-ioctl="" h="">#include <media videobuf-core="" h="">#include <linux clk="" h="">#include #define OV7740_INIT_REGS_SIZE (sizeof(ov7740_setting_30fps_VGA_640_480)/sizeof(ov7740_setting_30fps_VGA_640_480[0]))#define CAM_SRC_HSIZE(640)#define CAM_SRC_VSIZE(480)#define CAM_ORDER_YCbYCr (0)#define CAM_ORDER_YCrYCb (1)#define CAM_ORDER_CbYCrY (2)#define CAM_ORDER_CrYCbY (3)#define WinHorOfst(0)#define WinVerOfst(0)struct cmos_ov7740_scaler {unsigned int PreHorRatio;//水平变比unsigned int PreVerRatio;//垂直变比unsigned int H_Shift;//水平比unsigned int V_Shift;//垂直比unsigned int PreDstWidth;//目标宽度unsigned int PreDstHeight;//目标高度unsigned int MainHorRatio;//预览主缩放的水平比unsigned int MainVerRatio;//预览主缩放的垂直比unsigned int SHfactor;//缩放变比unsigned int ScaleUpDown;//放大缩小标志};static struct cmos_ov7740_scaler sc;typedef struct cmos_ov7740_i2c_value {unsigned char regaddr;unsigned char value;}ov7740_t;/* init: 640x480,30fps的,YUV422输出格式 */ov7740_t ov7740_setting_30fps_VGA_640_480[] ={{0x12, 0x80},{0x47, 0x02},{0x17, 0x27},{0x04, 0x40},{0x1B, 0x81},{0x29, 0x17},{0x5F, 0x03},{0x3A, 0x09},{0x33, 0x44},{0x68, 0x1A},{0x14, 0x38},{0x5F, 0x04},{0x64, 0x00},{0x67, 0x90},{0x27, 0x80},{0x45, 0x41},{0x4B, 0x40},{0x36, 0x2f},{0x11, 0x01},{0x36, 0x3f},{0x0c, 0x12},{0x12, 0x00},{0x17, 0x25},{0x18, 0xa0},{0x1a, 0xf0},{0x31, 0xa0},{0x32, 0xf0},{0x85, 0x08},{0x86, 0x02},{0x87, 0x01},{0xd5, 0x10},{0x0d, 0x34},{0x19, 0x03},{0x2b, 0xf8},{0x2c, 0x01},{0x53, 0x00},{0x89, 0x30},{0x8d, 0x30},{0x8f, 0x85},{0x93, 0x30},{0x95, 0x85},{0x99, 0x30},{0x9b, 0x85},{0xac, 0x6E},{0xbe, 0xff},{0xbf, 0x00},{0x38, 0x14},{0xe9, 0x00},{0x3D, 0x08},{0x3E, 0x80},{0x3F, 0x40},{0x40, 0x7F},{0x41, 0x6A},{0x42, 0x29},{0x49, 0x64},{0x4A, 0xA1},{0x4E, 0x13},{0x4D, 0x50},{0x44, 0x58},{0x4C, 0x1A},{0x4E, 0x14},{0x38, 0x11},{0x84, 0x70}};struct cmos_ov7740_fmt {char *name;u32 fourcc; /* v4l2 format id */int depth;};/* 这两个格式仅仅是预览通道支持的格式，由控制器的芯片手册可知 */static struct cmos_ov7740_fmt formats[] = {{.name = "RGB565",.fourcc = V4L2_PIX_FMT_RGB565,.depth = 16,},{.name = "PACKED_RGB_888",.fourcc = V4L2_PIX_FMT_RGB24,.depth = 24,},};struct camif_buffer{unsigned int order;unsigned long virt_base;unsigned long phy_base;};struct camif_buffer img_buff[] ={{.order = 0,.virt_base = (unsigned long)NULL,.phy_base = (unsigned long)NULL},{.order = 0,.virt_base = (unsigned long)NULL,.phy_base = (unsigned long)NULL},{.order = 0,.virt_base = (unsigned long)NULL,.phy_base = (unsigned long)NULL},{.order = 0,.virt_base = (unsigned long)NULL,.phy_base = (unsigned long)NULL}};static struct i2c_client *cmos_ov7740_client;// CAMIF GPIOstatic unsigned long *GPJCON;static unsigned long *GPJDAT;static unsigned long *GPJUP;// CAMIFstatic unsigned long *CISRCFMT;static unsigned long *CIWDOFST;static unsigned long *CIGCTRL;static unsigned long *CIPRCLRSA1;static unsigned long *CIPRCLRSA2;static unsigned long *CIPRCLRSA3;static unsigned long *CIPRCLRSA4;static unsigned long *CIPRTRGFMT;static unsigned long *CIPRCTRL;static unsigned long *CIPRSCPRERATIO;static unsigned long *CIPRSCPREDST;static unsigned long *CIPRSCCTRL;static unsigned long *CIPRTAREA;static unsigned long *CIIMGCPT;// IRQstatic unsigned long *SRCPND;static unsigned long *INTPND;static unsigned long *SUBSRCPND;static unsigned int SRC_Width, SRC_Height;static unsigned int TargetHsize_Pr, TargetVsize_Pr;static unsigned long buf_size;static unsigned int bytesperline;static DECLARE_WAIT_QUEUE_HEAD(cam_wait_queue);/* 中断标志 */static volatile int ev_cam = 0;static irqreturn_t cmos_ov7740_camif_irq_c(int irq, void *dev_id) {return IRQ_HANDLED;}static irqreturn_t cmos_ov7740_camif_irq_p(int irq, void *dev_id) {/* 清中断，因为不是使用上升沿或者下降沿触发，所以我们要清楚中断标志位 * 确保下次能继续产生中断。由中断控制器的手册394页可知，向相应的寄存器写入1 * 就是清除相应的中断标识，写入0表示保持原来的标志不变。 */*SRCPND = 1<<6;*INTPND = 1<<6;*SUBSRCPND = 1<<12 ev_cam="1;" wake_up_interruptible="" cam_wait_queue="" return="" irq_handled="" a2="" uvc_v4l2_do_ioctl="" static="" int="" cmos_ov7740_vidioc_querycap="" struct="" file="" file="" void="" priv="" struct="" v4l2_capability="" cap="" memset="" cap="" 0="" sizeof="" cap="" strcpy="" cap-="">driver, "cmos_ov7740");strcpy(cap->card, "cmos_ov7740");cap->version = 2;/* V4L2_CAP_READWRITE表示获取摄像头数据使用过读写操作，不是通过流操作 * 所谓流操作就是通过qbuf,dqbuf,mmap,poll等函数来获得数据的 */cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE;return 0;}/* A3 列举支持哪种格式 * 参考: uvc_fmts 数组 */static int cmos_ov7740_vidioc_enum_fmt_vid_cap(struct file *file, void *priv,struct v4l2_fmtdesc *f){struct cmos_ov7740_fmt *fmt;if (f->index >= ARRAY_SIZE(formats))return -EINVAL;fmt = &formats[f->index];strlcpy(f->description, fmt->name, sizeof(f->description));f->pixelformat = fmt->fourcc;return 0;}/* A4 返回当前所使用的格式 */static int cmos_ov7740_vidioc_g_fmt_vid_cap(struct file *file, void *priv,struct v4l2_format *f){return 0;}/* A5 测试驱动程序是否支持某种格式, 强制设置该格式 * 参考: uvc_v4l2_try_format * myvivi_vidioc_try_fmt_vid_cap */static int cmos_ov7740_vidioc_try_fmt_vid_cap(struct file *file, void *priv,struct v4l2_format *f){/* 判断是否为摄像头设备 */if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE){return -EINVAL;}/* 在coms中的CICOSCCTRL寄存器中可知，在预览通道只支持RGB16/RGB24 */if ((f->fmt.pix.pixelformat != V4L2_PIX_FMT_RGB565) && (f->fmt.pix.pixelformat != V4L2_PIX_FMT_RGB24))return -EINVAL;return 0;}/* A6 参考 myvivi_vidioc_s_fmt_vid_cap * 设置摄像头数据格式 */static int cmos_ov7740_vidioc_s_fmt_vid_cap(struct file *file, void *priv,struct v4l2_format *f){int ret = cmos_ov7740_vidioc_try_fmt_vid_cap(file, NULL, f);if (ret < 0)return ret;/* 目标图像的水平像素大小 */TargetHsize_Pr = f->fmt.pix.width;/* 目标图像的垂直像素大小 */TargetVsize_Pr = f->fmt.pix.height;if(f->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565){/* bit[30]: 设置图像输出格式是RGB16、RGB24 */*CIPRSCCTRL &= ~(1<<30 f-="">fmt.pix.bytesperline = (f->fmt.pix.width * 16) >> 3;f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;buf_size = f->fmt.pix.sizeimage;bytesperline = f->fmt.pix.bytesperline;}else if(f->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB24){/* bit[30]: 设置图像输出格式是RGB16、RGB24 */*CIPRSCCTRL |= (1<<30 rgb24="" 32="" s3c2440="" 515="" f-="">fmt.pix.bytesperline = (f->fmt.pix.width * 32) >> 3;f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;buf_size = f->fmt.pix.sizeimage;bytesperline = f->fmt.pix.bytesperline;}/*CIPRTRGFMT:bit[28:16] -- 表示目标图片的水平像素大小(TargetHsize_Pr)bit[15:14] -- 是否旋转，我们这个驱动就不选择了bit[12:0] -- 表示目标图片的垂直像素大小(TargetVsize_Pr)*/*CIPRTRGFMT = (TargetHsize_Pr<<16)|(0x0<<14)|(TargetVsize_Pr<<0 return="" 0="" ciprclrsa1="" static="" int="" cmos_ov7740_vidioc_reqbufs="" struct="" file="" file="" void="" priv="" struct="" v4l2_requestbuffers="" p="" unsigned="" int="" order="" __get_free_pages="" get_order="" order="get_order(buf_size);" img_buff="" 0="" order="order;" __get_free_pages="" 4m="" kmalloc="" 128k="" img_buff="" 0="" virt_base="__get_free_pages(GFP_KERNEL|__GFP_DMA," img_buff="" 0="" order="" if="" img_buff="" 0="" virt_base="=" unsigned="" long="" null="" printk="" error0="" n="" goto="" error0="" ciprclrsa1="" img_buff="" 0="" phy_base="__virt_to_phys(img_buff[0].virt_base);" img_buff="" 1="" order="order;" img_buff="" 1="" virt_base="__get_free_pages(GFP_KERNEL|__GFP_DMA," img_buff="" 1="" order="" if="" img_buff="" 1="" virt_base="=" unsigned="" long="" null="" printk="" error1="" n="" goto="" error1="" img_buff="" 1="" phy_base="__virt_to_phys(img_buff[1].virt_base);" img_buff="" 2="" order="order;" img_buff="" 2="" virt_base="__get_free_pages(GFP_KERNEL|__GFP_DMA," img_buff="" 2="" order="" if="" img_buff="" 2="" virt_base="=" unsigned="" long="" null="" printk="" error2="" n="" goto="" error2="" img_buff="" 2="" phy_base="__virt_to_phys(img_buff[2].virt_base);" img_buff="" 3="" order="order;" img_buff="" 3="" virt_base="__get_free_pages(GFP_KERNEL|__GFP_DMA," img_buff="" 3="" order="" if="" img_buff="" 3="" virt_base="=" unsigned="" long="" null="" printk="" error3="" n="" goto="" error3="" img_buff="" 3="" phy_base="__virt_to_phys(img_buff[3].virt_base);" ciprclrsa1="" ciprclrsa1="img_buff[0].phy_base;" ciprclrsa2="img_buff[1].phy_base;" ciprclrsa3="img_buff[2].phy_base;" ciprclrsa4="img_buff[3].phy_base;" return="" 0="" error3:="" free_pages="" img_buff="" 2="" virt_base="" order="" img_buff="" 2="" phy_base="(unsigned" long="" null="" error2:="" free_pages="" img_buff="" 1="" virt_base="" order="" img_buff="" 1="" phy_base="(unsigned" long="" null="" error1:="" free_pages="" img_buff="" 0="" virt_base="" order="" img_buff="" 0="" phy_base="(unsigned" long="" null="" error0:="" return="" -enomem="" 2440="" 532="" static="" void="" calculateburstsize="" unsigned="" int="" hsize="" unsigned="" int="" mainbusrtsize="" unsigned="" int="" remainedbustsize="" unsigned="" int="" tmp="" 2="" 4="" 8="" 16="" 16="" tmp="(hSize/4)%16;" switch="" tmp="" case="" 0:="" mainbusrtsize="16;" remainedbustsize="16;" break="" case="" 4:="" mainbusrtsize="16;" remainedbustsize="4;" break="" case="" 8:="" mainbusrtsize="16;" remainedbustsize="8;" break="" 16="" 8="" default:="" tmp="(hSize/4)%8;" switch="" tmp="" case="" 0:="" mainbusrtsize="8;" remainedbustsize="8;" break="" case="" 4:="" mainbusrtsize="8;" remainedbustsize="4;" break="" 8="" 4="" default:="" mainbusrtsize="4;" tmp="(hSize/4)%4;" remainedbustsize="(tmp)?tmp:4;" break="" break="" jz2440="" 527="" static="" void="" camif_get_scaler_factor="" u32="" src="" u32="" tar="" u32="" ratio="" u32="" shift="" if="" src="">= 64*tar) {return;}else if(src >= 32*tar) {*ratio = 32; *shift = 5;}else if(src >= 16*tar) {*ratio = 16; *shift = 4;}else if(src >= 8*tar) {*ratio = 8; *shift = 3;}else if(src >= 4*tar) {*ratio = 4; *shift = 2;}else if(src >= 2*tar) {*ratio = 2; *shift = 1;}else {*ratio = 1; *shift = 0;}}/* 计算公式在2440用户手册的527页 */static void cmos_ov7740_calculate_scaler_info(void){unsigned int sx, sy, tx, ty;/* 这里的源宽度和源高度是经过窗口剪切的图像数据 * 这里的目标宽度和高度是应用程序在cmos_ov7740_vidioc_s_fmt_vid_cap函数 * 设置数据格式时传入的，表示应用程序想要获得的图像分辨率 */sx = SRC_Width;sy = SRC_Height;tx = TargetHsize_Pr;ty = TargetVsize_Pr;printk("%s: SRC_in(%d, %d), Target_out(%d, %d)\n", __func__, sx, sy, tx, ty);camif_get_scaler_factor(sx, tx, &sc.PreHorRatio, &sc.H_Shift);camif_get_scaler_factor(sy, ty, &sc.PreVerRatio, &sc.V_Shift);sc.PreDstWidth = sx / sc.PreHorRatio;sc.PreDstHeight = sy / sc.PreVerRatio;sc.MainHorRatio = (sx << 8) / (tx << sc.H_Shift);sc.MainVerRatio = (sy << 8) / (ty << sc.V_Shift);sc.SHfactor = 10 - (sc.H_Shift + sc.V_Shift);sc.ScaleUpDown = (tx>=sx)?1:0;}/* A11 启动传输 * 参考: uvc_video_enable(video, 1): * uvc_commit_video * uvc_init_video */static int cmos_ov7740_vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i){unsigned int Main_burst, Remained_burst;/*CISRCFMT:bit[31]-- 选择传输方式为BT601或者BT656bit[30]-- 设置偏移值(0 = +0 (正常情况下) - for YCbCr)bit[29]-- 保留位,必须设置为0bit[28:16]-- 设置源图片的水平像素值(640)bit[15:14]-- 设置源图片的颜色顺序(0x0c --> 0x2),由摄像头地址为0xc的寄存器可知，输出的顺序为UYVYUYVY------>CbYCrYCbYCrY,bit[12:0]-- 设置源图片的垂直像素值(480)水平和垂直的像素值是摄像头模块输入的，查看摄像头模块输出水平和垂直的像素值即可*/*CISRCFMT |= (0<<30)|(0<<29)|(CAM_SRC_HSIZE<<16)|(CAM_ORDER_CbYCrY<<14)|(CAM_SRC_VSIZE<<0);/*CIWDOFST:bit[31]-- 1 = 使能窗口功能、0 = 不使用窗口功能bit[30、15:12]-- 清除溢出标志位bit[26:16]-- 水平方向的裁剪的大小bit[10:0]-- 垂直方向的裁剪的大小*/*CIWDOFST |=(1<<30)|(0xf<<12);*CIWDOFST |= (1<<31)|(WinHorOfst<<16)|(WinVerOfst<<0);/* 裁剪后的图像宽度 = 原始图像宽度 - 2*水平窗口宽度 */SRC_Width = CAM_SRC_HSIZE - 2*WinHorOfst;/* 裁剪后的图像高度 = 原始图像高度 - 2*水平窗口高度 */SRC_Height = CAM_SRC_VSIZE - 2*WinVerOfst;/*CIGCTRL:bit[31]-- 软件复位CAMIF控制器bit[30]-- 用于复位外部摄像头模块bit[29]-- 保留位，必须设置为1bit[28:27]-- 用于选择信号源(00 = 输入源来自摄像头模块)bit[26]-- 设置像素时钟的极性(猜0)bit[25]-- 设置VSYNC的极性(0)bit[24]-- 设置HREF的极性(0)，行同步信号*/*CIGCTRL |= (1<<29)|(0<<27)|(0<<26)|(0<<25)|(0<<24);/*CIPRCTRL:bit[23:19] -- 主突发长度(Main_burst)bit[18:14] -- 剩余突发长度(Remained_burst)bit[2] -- 是否使能LastIRQ功能(不使能)*/CalculateBurstSize(bytesperline, &Main_burst, &Remained_burst);*CIPRCTRL = (Main_burst<<19)|(Remained_burst<<14)|(0<<2);/*CIPRSCPRERATIO:bit[31:28]: 预览缩放的变化系数(SHfactor_Pr)bit[22:16]: 预览缩放的水平比(PreHorRatio_Pr)bit[6:0]: 预览缩放的垂直比(PreVerRatio_Pr)CIPRSCPREDST:bit[27:16]: 预览缩放的目标宽度(PreDstWidth_Pr)bit[11:0]: 预览缩放的目标高度(PreDstHeight_Pr)CIPRSCCTRL:bit[29:28]: 告诉摄像头控制器(图片是缩小、放大)(ScaleUpDown_Pr)bit[24:16]: 预览主缩放的水平比(MainHorRatio_Pr)bit[8:0]: 预览主缩放的垂直比(MainVerRatio_Pr)bit[31]: 必须固定设置为1bit[30]: 设置图像输出格式是RGB16、RGB24bit[15]: 预览缩放开始//bit[30]在cmos_ov7740_vidioc_s_fmt_vid_cap函数中设置*/cmos_ov7740_calculate_scaler_info();*CIPRSCPRERATIO = (sc.SHfactor<<28)|(sc.PreHorRatio<<16)|(sc.PreVerRatio<<0);*CIPRSCPREDST = (sc.PreDstWidth<<16)|(sc.PreDstHeight<<0);*CIPRSCCTRL |= (1<<31)|(sc.ScaleUpDown<<28)|(sc.MainHorRatio<<16)|(sc.MainVerRatio<<0);/*CIPRTAREA:表示预览通道的目标区域*/*CIPRTAREA = TargetHsize_Pr * TargetVsize_Pr;/*CIIMGCPT:bit[31]: 用来使能摄像头控制器bit[30]: 使能编码通道bit[29]: 使能预览通道*/*CIIMGCPT = (1<<31)|(1<<29);*CIPRSCCTRL |= (1<<15);return 0;}/* A17 停止 * 参考 : uvc_video_enable(video, 0) */static int cmos_ov7740_vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type t){*CIPRSCCTRL &= ~(1<<15);*CIIMGCPT &= ~((1<<31)|(1<<29));return 0;}static const struct v4l2_ioctl_ops cmos_ov7740_ioctl_ops = { // 表示它是一个摄像头设备 .vidioc_querycap = cmos_ov7740_vidioc_querycap, /* 用于列举、获得、测试、设置摄像头的数据的格式 */ .vidioc_enum_fmt_vid_cap = cmos_ov7740_vidioc_enum_fmt_vid_cap, .vidioc_g_fmt_vid_cap = cmos_ov7740_vidioc_g_fmt_vid_cap, .vidioc_try_fmt_vid_cap = cmos_ov7740_vidioc_try_fmt_vid_cap, .vidioc_s_fmt_vid_cap = cmos_ov7740_vidioc_s_fmt_vid_cap, /* 缓冲区操作: 申请/查询/放入队列/取出队列 */ .vidioc_reqbufs = cmos_ov7740_vidioc_reqbufs,/* 说明: 因为我们是通过读的方式来获得摄像头数据,因此查询/放入队列/取出队列这些操作函数将不在需要 */#if 0 .vidioc_querybuf = myuvc_vidioc_querybuf, .vidioc_qbuf = myuvc_vidioc_qbuf, .vidioc_dqbuf = myuvc_vidioc_dqbuf,#endif // 启动/停止 .vidioc_streamon = cmos_ov7740_vidioc_streamon, .vidioc_streamoff = cmos_ov7740_vidioc_streamoff, };/* A1 */static int cmos_ov7740_open(struct file *file){return 0;}/* A18 关闭 */static int cmos_ov7740_close(struct file *file){ return 0;}/* 应用程序通过读的方式读取摄像头的数据 */static ssize_t cmos_ov7740_read(struct file *filep, char __user *buf, size_t count, loff_t *pos){size_t end;int i;/* 取一帧数据的大小和用户想要读取数据的大小的最小值 */end = min_t(size_t, buf_size, count);wait_event_interruptible(cam_wait_queue, ev_cam);for(i=0; i<4; i++){if(copy_to_user(buf, (void *)img_buff[i].virt_base, end))return -EFAULT;}ev_cam = 0;return end;}/* 应用程序使用read函数来获取摄像头数据，所以不再需要mmap，poll函数。 */static const struct v4l2_file_operations cmos_ov7740_fops = {.owner= THIS_MODULE,.open = cmos_ov7740_open,.release = cmos_ov7740_close,/* video_ioctl2是内核提供的函数，只是起到中转的作用，最后会调用video_device中的ioctl_ops */.unlocked_ioctl = video_ioctl2,.read= cmos_ov7740_read,};/*注意:该函数是必须的,否则在insmod的时候，会出错*/static void cmos_ov7740_release(struct video_device *vdev){unsigned int order;order = get_order(buf_size);free_pages(img_buff[0].virt_base, order);img_buff[0].phy_base = (unsigned long)NULL;free_pages(img_buff[1].virt_base, order);img_buff[1].phy_base = (unsigned long)NULL;free_pages(img_buff[2].virt_base, order);img_buff[2].phy_base = (unsigned long)NULL;free_pages(img_buff[3].virt_base, order);img_buff[3].phy_base = (unsigned long)NULL;}/* 2.1. 分配、设置一个video_device结构体 * 这里采用的是静态分配结构体，使用video_device_alloc()是动态分配摄像头结构体 */static struct video_device cmos_ov7740_vdev = {.fops= &cmos_ov7740_fops,.ioctl_ops= &cmos_ov7740_ioctl_ops,.release= cmos_ov7740_release,.name= "cmos_ov7740",};static void cmos_ov7740_gpio_cfg(void){/* 设置相应的GPIO用于CAMIF */*GPJCON = 0x2aaaaaa;/* 将数据位清0 */*GPJDAT = 0;/* 为了让信号稳定，使能上拉电阻 */*GPJUP = 0;}static void cmos_ov7740_camif_reset(void){/* 传输方式为BT601 */*CISRCFMT |= (1<<31);/* 复位CAMIF控制器 */*CIGCTRL |= (1<<31);/* 稍微延迟一下 */mdelay(10);/* 使摄像头恢复正常状态 */*CIGCTRL &= ~(1<<31 mdelay="" 10="" static="" void="" cmos_ov7740_clk_cfg="" void="" struct="" clk="" camif_clk="" struct="" clk="" camif_upll_clk="" camif="" clk_get="" soc="" source="" insight="" camif="" s3c2440="" camif_clk="clk_get(NULL," camif="" if="" camif_clk="" is_err="" camif_clk="" printk="" kern_info="" failed="" to="" get="" camif="" clock="" source="" n="" clk_enable="" camif_clk="" camclk="24MHz，设置外部摄像头的时钟" camif-upll="" usb="" soc="" usb="" soc="" camif_upll_clk="clk_get(NULL," camif-upll="" clk_set_rate="" camif_upll_clk="" 24000000="" mdelay="" 100="" :="" 1="" s3c2440="" camrst="" :0-="">1->0(0:表示正常工作的电平、1:表示复位电平) 但是，实验证明，该复位时序与我们的OV7740需要的复位时序(1->0->1)不符合。2.因此，我们就应该结合OV7740的具体复位时序，来设置相应的寄存器。*/static void cmos_ov7740_reset(void){*CIGCTRL |= (1<<30);mdelay(30);*CIGCTRL &= ~(1<<30);mdelay(30);*CIGCTRL |= (1<<30);mdelay(30);}static void cmos_ov7740_init(void){unsigned int mid;int i;/* 读 * 0xa是摄像头模块的厂家id的高8位，0xb是厂家id的低8位 * i2c_smbus_read_byte_data函数是内核提供的函数，也可是使用i2c_transfer函数 */mid = i2c_smbus_read_byte_data(cmos_ov7740_client, 0x0a)<<8;mid |= i2c_smbus_read_byte_data(cmos_ov7740_client, 0x0b);printk("manufacture ID = 0x%4x\n", mid);/* 写 * 初始化摄像头模块 */for(i = 0; i < OV7740_INIT_REGS_SIZE; i++){i2c_smbus_write_byte_data(cmos_ov7740_client, ov7740_setting_30fps_VGA_640_480[i].regaddr, ov7740_setting_30fps_VGA_640_480[i].value);mdelay(2);}}static int __devinit cmos_ov7740_probe(struct i2c_client *client, const struct i2c_device_id *id){printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);/* 2.3 硬件相关 *//* 2.3.1 映射相应的寄存器 */GPJCON = ioremap(0x560000d0, 4);GPJDAT = ioremap(0x560000d4, 4);/* 上拉电阻相关的寄存器 */ GPJUP = ioremap(0x560000d8, 4);/* 以下是摄像头控制器的寄存器 */CISRCFMT = ioremap(0x4F000000, 4);CIWDOFST = ioremap(0x4F000004, 4);CIGCTRL = ioremap(0x4F000008, 4);CIPRCLRSA1 = ioremap(0x4F00006C, 4);CIPRCLRSA2 = ioremap(0x4F000070, 4);CIPRCLRSA3 = ioremap(0x4F000074, 4);CIPRCLRSA4 = ioremap(0x4F000078, 4);CIPRTRGFMT = ioremap(0x4F00007C, 4);CIPRCTRL = ioremap(0x4F000080, 4);CIPRSCPRERATIO = ioremap(0x4F000084, 4);CIPRSCPREDST = ioremap(0x4F000088, 4);CIPRSCCTRL = ioremap(0x4F00008C, 4);CIPRTAREA = ioremap(0x4F000090, 4);CIIMGCPT = ioremap(0x4F0000A0, 4);SRCPND = ioremap(0X4A000000, 4);INTPND = ioremap(0X4A000010, 4);SUBSRCPND = ioremap(0X4A000018, 4);/* 2.3.2 设置相应的GPIO用于CAMIF */cmos_ov7740_gpio_cfg();/* 2.3.3 复位一下CAMIF控制器 * 接下来要操作摄像头控制器，因此要先复位一下控制器 */cmos_ov7740_camif_reset();/* 2.3.4 设置、使能时钟(使能HCLK用于摄像头控制器、使能并设置CAMCLK = 24MHz用于外部摄像头) */cmos_ov7740_clk_cfg();/* 2.3.5 复位一下摄像头模块 */cmos_ov7740_reset();/* 2.3.6 通过IIC总线,初始化摄像头模块 */cmos_ov7740_client = client;cmos_ov7740_init();/* 2.3.7 注册中断 * IRQF_DISABLED - keep irqs disabled when calling the action handler */if (request_irq(IRQ_S3C2440_CAM_C, cmos_ov7740_camif_irq_c, IRQF_DISABLED , "CAM_C", NULL))printk("%s:request_irq failed\n", __func__);if (request_irq(IRQ_S3C2440_CAM_P, cmos_ov7740_camif_irq_p, IRQF_DISABLED , "CAM_P", NULL))printk("%s:request_irq failed\n", __func__);/* 3. 注册 ,以下信息是通过追踪源代码得到的结论 * 参数-1表示分配第一个可用的号 * which device node number (0 == /dev/video0, 1 == /dev/video1, ... * -1 == first free) */ if(video_register_device(&cmos_ov7740_vdev, VFL_TYPE_GRABBER, -1)){printk("unable to register video device\n");}return 0;}static int __devexit cmos_ov7740_remove(struct i2c_client *client){printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);iounmap(GPJCON);iounmap(GPJDAT);iounmap(GPJUP);iounmap(CISRCFMT);iounmap(CIWDOFST);iounmap(CIGCTRL);iounmap(CIPRCLRSA1);iounmap(CIPRCLRSA2);iounmap(CIPRCLRSA3);iounmap(CIPRCLRSA4);iounmap(CIPRTRGFMT);iounmap(CIPRCTRL);iounmap(CIPRSCPRERATIO);iounmap(CIPRSCPREDST);iounmap(CIPRSCCTRL);iounmap(CIPRTAREA);iounmap(CIIMGCPT);iounmap(SRCPND);iounmap(INTPND);iounmap(SUBSRCPND);free_irq(IRQ_S3C2440_CAM_C, NULL);free_irq(IRQ_S3C2440_CAM_P, NULL);video_unregister_device(&cmos_ov7740_vdev);return 0;}static const struct i2c_device_id cmos_ov7740_id_table[] = {{ "cmos_ov7740", 0 },{}};/* 1.1. 分配、设置一个i2c_driver */static struct i2c_driver cmos_ov7740_driver = {.driver= {/* 用于和iic设备进行匹配，必须和iic_dev中的名字一样，否则匹配不成功 */.name= "cmos_ov7740",.owner= THIS_MODULE,},.probe= cmos_ov7740_probe,.remove= __devexit_p(cmos_ov7740_remove),.id_table= cmos_ov7740_id_table,};static int cmos_ov7740_drv_init(void){/* 1.2.注册 */i2c_add_driver(&cmos_ov7740_driver);return 0;}static void cmos_ov7740_drv_exit(void){i2c_del_driver(&cmos_ov7740_driver);}module_init(cmos_ov7740_drv_init);module_exit(cmos_ov7740_drv_exit);MODULE_LICENSE("GPL");</31></0></30></30></12></asm></linux></media></media></media></asm></asm></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux></linux>