From ab121f379a3cff458c90e6f480ba4bb68c8733dd Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Sat, 27 Nov 2010 07:49:17 +0100 Subject: Linux Device Drivers 3 examples --- scullv/scullv.h | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 scullv/scullv.h (limited to 'scullv/scullv.h') diff --git a/scullv/scullv.h b/scullv/scullv.h new file mode 100644 index 0000000..8ba2595 --- /dev/null +++ b/scullv/scullv.h @@ -0,0 +1,122 @@ +/* -*- C -*- + * scullv.h -- definitions for the scullv char module + * + * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet + * Copyright (C) 2001 O'Reilly & Associates + * + * The source code in this file can be freely used, adapted, + * and redistributed in source or binary form, so long as an + * acknowledgment appears in derived source files. The citation + * should list that the code comes from the book "Linux Device + * Drivers" by Alessandro Rubini and Jonathan Corbet, published + * by O'Reilly & Associates. No warranty is attached; + * we cannot take responsibility for errors or fitness for use. + */ + +#include +#include + +/* + * Macros to help debugging + */ + +#undef PDEBUG /* undef it, just in case */ +#ifdef SCULLV_DEBUG +# ifdef __KERNEL__ + /* This one if debugging is on, and kernel space */ +# define PDEBUG(fmt, args...) printk( KERN_DEBUG "scullv: " fmt, ## args) +# else + /* This one for user space */ +# define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args) +# endif +#else +# define PDEBUG(fmt, args...) /* not debugging: nothing */ +#endif + +#undef PDEBUGG +#define PDEBUGG(fmt, args...) /* nothing: it's a placeholder */ + +#define SCULLV_MAJOR 0 /* dynamic major by default */ + +#define SCULLV_DEVS 4 /* scullv0 through scullv3 */ + +/* + * The bare device is a variable-length region of memory. + * Use a linked list of indirect blocks. + * + * "scullv_dev->data" points to an array of pointers, each + * pointer refers to a memory page. + * + * The array (quantum-set) is SCULLV_QSET long. + */ +#define SCULLV_ORDER 4 /* 16 pages at a time */ +#define SCULLV_QSET 500 + +struct scullv_dev { + void **data; + struct scullv_dev *next; /* next listitem */ + int vmas; /* active mappings */ + int order; /* the current allocation order */ + int qset; /* the current array size */ + size_t size; /* 32-bit will suffice */ + struct semaphore sem; /* Mutual exclusion */ + struct cdev cdev; +}; + +extern struct scullv_dev *scullv_devices; + +extern struct file_operations scullv_fops; + +/* + * The different configurable parameters + */ +extern int scullv_major; /* main.c */ +extern int scullv_devs; +extern int scullv_order; +extern int scullv_qset; + +/* + * Prototypes for shared functions + */ +int scullv_trim(struct scullv_dev *dev); +struct scullv_dev *scullv_follow(struct scullv_dev *dev, int n); + + +#ifdef SCULLV_DEBUG +# define SCULLV_USE_PROC +#endif + +/* + * Ioctl definitions + */ + +/* Use 'K' as magic number */ +#define SCULLV_IOC_MAGIC 'K' + +#define SCULLV_IOCRESET _IO(SCULLV_IOC_MAGIC, 0) + +/* + * S means "Set" through a ptr, + * T means "Tell" directly + * G means "Get" (to a pointed var) + * Q means "Query", response is on the return value + * X means "eXchange": G and S atomically + * H means "sHift": T and Q atomically + */ +#define SCULLV_IOCSORDER _IOW(SCULLV_IOC_MAGIC, 1, int) +#define SCULLV_IOCTORDER _IO(SCULLV_IOC_MAGIC, 2) +#define SCULLV_IOCGORDER _IOR(SCULLV_IOC_MAGIC, 3, int) +#define SCULLV_IOCQORDER _IO(SCULLV_IOC_MAGIC, 4) +#define SCULLV_IOCXORDER _IOWR(SCULLV_IOC_MAGIC, 5, int) +#define SCULLV_IOCHORDER _IO(SCULLV_IOC_MAGIC, 6) +#define SCULLV_IOCSQSET _IOW(SCULLV_IOC_MAGIC, 7, int) +#define SCULLV_IOCTQSET _IO(SCULLV_IOC_MAGIC, 8) +#define SCULLV_IOCGQSET _IOR(SCULLV_IOC_MAGIC, 9, int) +#define SCULLV_IOCQQSET _IO(SCULLV_IOC_MAGIC, 10) +#define SCULLV_IOCXQSET _IOWR(SCULLV_IOC_MAGIC,11, int) +#define SCULLV_IOCHQSET _IO(SCULLV_IOC_MAGIC, 12) + +#define SCULLV_IOC_MAXNR 12 + + + -- cgit v1.2.1-18-gbd029