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 --- sbull/sbull.h | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 sbull/sbull.h (limited to 'sbull/sbull.h') diff --git a/sbull/sbull.h b/sbull/sbull.h new file mode 100644 index 0000000..c443d70 --- /dev/null +++ b/sbull/sbull.h @@ -0,0 +1,71 @@ + +/* + * sbull.h -- definitions for the 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 + +/* Multiqueue only works on 2.4 */ +#ifdef SBULL_MULTIQUEUE +# warning "Multiqueue only works on 2.4 kernels" +#endif + +/* + * Macros to help debugging + */ + +#undef PDEBUG /* undef it, just in case */ +#ifdef SBULL_DEBUG +# ifdef __KERNEL__ + /* This one if debugging is on, and kernel space */ +# define PDEBUG(fmt, args...) printk( KERN_DEBUG "sbull: " 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 SBULL_MAJOR 0 /* dynamic major by default */ +#define SBULL_DEVS 2 /* two disks */ +#define SBULL_RAHEAD 2 /* two sectors */ +#define SBULL_SIZE 2048 /* two megs each */ +#define SBULL_BLKSIZE 1024 /* 1k blocks */ +#define SBULL_HARDSECT 512 /* 2.2 and 2.4 can used different values */ + +#define SBULLR_MAJOR 0 /* Dynamic major for raw device */ +/* + * The sbull device is removable: if it is left closed for more than + * half a minute, it is removed. Thus use a usage count and a + * kernel timer + */ + +typedef struct Sbull_Dev { + int size; + int usage; + struct timer_list timer; + spinlock_t lock; + u8 *data; +#ifdef SBULL_MULTIQUEUE + request_queue_t *queue; + int busy; +#endif +} Sbull_Dev; -- cgit v1.2.1-18-gbd029