added buffer info ioctl

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index d843508eaaf7e9f180fc6a6b9f3c86ffd6ad580f..7df2b3eccc06f6dfbb68b559fc4e5b97e85cefab 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -52,6 +52,7 @@ static int do_bufconfig_ioctl(comedi_device *dev,void *arg);
 static int do_devinfo_ioctl(comedi_device *dev,comedi_devinfo *arg);
 static int do_subdinfo_ioctl(comedi_device *dev,comedi_subdinfo *arg,void *file);
 static int do_chaninfo_ioctl(comedi_device *dev,comedi_chaninfo *arg);
+static int do_bufinfo_ioctl(comedi_device *dev,void *arg);
 #ifdef CONFIG_COMEDI_MODE_CORE
 static int do_trig_ioctl(comedi_device *dev,void *arg,void *file);
 #endif
@@ -71,7 +72,7 @@ static int comedi_ioctl(struct inode * inode,struct file * file,unsigned int cmd
 {
        kdev_t minor=MINOR(inode->i_rdev);
        comedi_device *dev=comedi_get_device_by_minor(minor);
-       
+
        switch(cmd)
        {
        case COMEDI_DEVCONFIG:
@@ -86,6 +87,8 @@ static int comedi_ioctl(struct inode * inode,struct file * file,unsigned int cmd
                return do_chaninfo_ioctl(dev,(void *)arg);
        case COMEDI_RANGEINFO:
                return do_rangeinfo_ioctl(dev,(void *)arg);
+       case COMEDI_BUFINFO:
+               return do_bufinfo_ioctl(dev,(void*)arg);
 #ifdef CONFIG_COMEDI_MODE_CORE
        case COMEDI_TRIG:
                return do_trig_ioctl(dev,(void *)arg,file);
@@ -111,20 +114,20 @@ static int comedi_ioctl(struct inode * inode,struct file * file,unsigned int cmd
 /*
        COMEDI_DEVCONFIG
        device config ioctl
-       
+
        arg:
                pointer to devconfig structure
-       
+
        reads:
                devconfig structure at arg
-       
+
        writes:
                none
 */
 static int do_devconfig_ioctl(comedi_device *dev,comedi_devconfig *arg,kdev_t minor)
 {
        comedi_devconfig it;
-       
+
        if(!suser())
                return -EPERM;
 
@@ -134,7 +137,7 @@ static int do_devconfig_ioctl(comedi_device *dev,comedi_devconfig *arg,kdev_t mi
 
        if(copy_from_user(&it,arg,sizeof(comedi_devconfig)))
                return -EFAULT;
-       
+
        it.board_name[COMEDI_NAMELEN-1]=0;
 
        return comedi_device_attach(dev,&it);
@@ -173,7 +176,7 @@ static int do_bufconfig_ioctl(comedi_device *dev,void *arg)
 
        if(bc.subdevice>=dev->n_subdevices || bc.subdevice<0)
                return -EINVAL;
-       
+
        s=dev->subdevices+bc.subdevice;
        async=s->async;
 
@@ -260,20 +263,20 @@ int resize_buf(comedi_device *dev, comedi_async *async, unsigned int size)
 
        arg:
                pointer to devinfo structure
-       
+
        reads:
                none
-       
+
        writes:
                devinfo structure
-               
+
 */
 static int do_devinfo_ioctl(comedi_device *dev,comedi_devinfo *arg)
 {
        comedi_devinfo devinfo;
-       
+
        memset(&devinfo,0,sizeof(devinfo));
-       
+
        /* fill devinfo structure */
        devinfo.version_code=COMEDI_VERSION_CODE;
        devinfo.n_subdevs=dev->n_subdevices;
@@ -319,19 +322,19 @@ static int do_subdinfo_ioctl(comedi_device *dev,comedi_subdinfo *arg,void *file)
        int ret,i;
        comedi_subdinfo *tmp,*us;
        comedi_subdevice *s;
-       
+
 
        tmp=kmalloc(dev->n_subdevices*sizeof(comedi_subdinfo),GFP_KERNEL);
        if(!tmp)
                return -ENOMEM;
-       
+
        memset(tmp,0,sizeof(comedi_subdinfo)*dev->n_subdevices);
 
        /* fill subdinfo structs */
        for(i=0;i<dev->n_subdevices;i++){
                s=dev->subdevices+i;
                us=tmp+i;
-               
+
                us->type                = s->type;
                us->n_chan              = s->n_chan;
                us->subd_flags          = s->subdev_flags;
@@ -394,23 +397,23 @@ static int do_subdinfo_ioctl(comedi_device *dev,comedi_subdinfo *arg,void *file)
        
        reads:
                chaninfo structure at arg
-       
+
        writes:
                arrays at elements of chaninfo structure
-       
+
 */
 static int do_chaninfo_ioctl(comedi_device *dev,comedi_chaninfo *arg)
 {
        comedi_subdevice *s;
        comedi_chaninfo it;
-       
+
        if(copy_from_user(&it,arg,sizeof(comedi_chaninfo)))
                return -EFAULT;
-       
+
        if(it.subdev>=dev->n_subdevices)
                return -EINVAL;
        s=dev->subdevices+it.subdev;
-       
+
        if(it.maxdata_list){
                if(s->maxdata || !s->maxdata_list)
                        return -EINVAL;
@@ -438,10 +441,85 @@ static int do_chaninfo_ioctl(comedi_device *dev,comedi_chaninfo *arg)
                //if(copy_to_user(it.rangelist,s->range_type_list,s->n_chan*sizeof(unsigned int)))
                //      return -EFAULT;
        }
-       
+
        return 0;
 }
 
+ /*
+       COMEDI_BUFINFO
+       buffer information ioctl
+
+       arg:
+               pointer to bufinfo structure
+
+       reads:
+               bufinfo at arg
+
+       writes:
+               modified bufinfo at arg
+
+*/
+static int do_bufinfo_ioctl(comedi_device *dev,void *arg)
+{
+       comedi_bufinfo bi;
+       comedi_subdevice *s;
+       comedi_async *async;
+       spinlock_t bufinfo_lock = SPIN_LOCK_UNLOCKED;
+       unsigned long irq_flags;
+       int m;
+
+       // perform sanity checks
+       if(!dev->attached)
+       {
+               DPRINTK("no driver configured on comedi%i\n", dev->minor);
+               return -ENODEV;
+       }
+
+       if(copy_from_user(&bi,arg, sizeof(comedi_bufinfo)))
+               return -EFAULT;
+
+       if(bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
+               return -EINVAL;
+
+       s=dev->subdevices + bi.subdevice;
+       async=s->async;
+
+       if(!async){
+               DPRINTK("subdevice does not have async capability\n");
+               bi.buf_int_ptr = 0;
+               bi.buf_user_ptr = 0;
+               bi.buf_int_count = 0;
+               bi.buf_user_count = 0;
+               goto copyback;
+       }
+
+       if(bi.bytes_read){
+
+               // check for buffer underflow
+               m = async->buf_int_count - async->buf_user_count;
+               if(bi.bytes_read > m)
+               {
+                       DPRINTK("buffer underflow\n");
+                       return -EIO;
+               }
+
+               async->buf_user_ptr += bi.bytes_read;
+               async->buf_user_count += bi.bytes_read;
+       }
+
+       comedi_spin_lock_irqsave(&bufinfo_lock, irq_flags);
+       bi.buf_int_count = async->buf_int_count;
+       bi.buf_int_ptr = async->buf_int_ptr;
+       comedi_spin_unlock_irqrestore(&bufinfo_lock, irq_flags);
+       bi.buf_user_count = async->buf_user_count;
+       bi.buf_user_ptr = async->buf_user_ptr;
+
+copyback:
+       if(copy_to_user(arg, &bi, sizeof(comedi_bufinfo)))
+               return -EFAULT;
+
+       return 0;
+}
 
 #ifdef CONFIG_COMEDI_MODE_CORE
 /*
@@ -1172,7 +1250,7 @@ static int do_lock_ioctl(comedi_device *dev,unsigned int arg,void * file)
 {
        int ret=0;
        comedi_subdevice *s;
-       
+
        if(!dev->attached)
        {
                DPRINTK("no driver configured on comedi%i\n", dev->minor);
@@ -1211,7 +1289,7 @@ static int do_lock_ioctl(comedi_device *dev,unsigned int arg,void * file)
 /*
        COMEDI_UNLOCK
        unlock subdevice
-       
+
        arg:
                subdevice number
 

diff --git a/include/linux/comedi.h b/include/linux/comedi.h
index a4e1915fae5250e1ca27a3b9edb8c85e023b6dc3..81f51bfbf81967af6bb94ac12f3773f7c458efe7 100644 (file)
--- a/include/linux/comedi.h
+++ b/include/linux/comedi.h
@@ -171,6 +171,7 @@ typedef unsigned short sampl_t;
 #define COMEDI_INSNLIST _IOR(CIO,11,comedi_insnlist)
 #define COMEDI_INSN _IOR(CIO,12,comedi_insn)
 #define COMEDI_BUFCONFIG _IOR(CIO,13,comedi_bufconfig)
+#define COMEDI_BUFINFO _IOWR(CIO,14,comedi_bufinfo)
 
 
 /* structures */
@@ -186,6 +187,7 @@ typedef struct comedi_devconfig_struct comedi_devconfig;
 typedef struct comedi_rangeinfo_struct comedi_rangeinfo;
 typedef struct comedi_krange_struct comedi_krange;
 typedef struct comedi_bufconfig_struct comedi_bufconfig;
+typedef struct comedi_bufinfo_struct comedi_bufinfo;
 
 struct comedi_trig_struct{
        unsigned int subdev;            /* subdevice */
@@ -298,6 +300,18 @@ struct comedi_bufconfig_struct{
        unsigned int unused[4];
 };
 
+struct comedi_bufinfo_struct{
+       unsigned int subdevice;
+       unsigned int bytes_read;
+
+       unsigned int buf_int_ptr;
+       unsigned int buf_user_ptr;
+       unsigned int buf_int_count;
+       unsigned int buf_user_count;
+
+       unsigned int unused[5];
+};
+
 /* range stuff */
 
 #define __RANGE(a,b)   ((((a)&0xffff)<<16)|((b)&0xffff))