diff options
Diffstat (limited to 'drivers/staging/dt3155/dt3155_isr.c')
| -rw-r--r-- | drivers/staging/dt3155/dt3155_isr.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/drivers/staging/dt3155/dt3155_isr.c b/drivers/staging/dt3155/dt3155_isr.c new file mode 100644 index 000000000000..fd7f93d6c33d --- /dev/null +++ b/drivers/staging/dt3155/dt3155_isr.c @@ -0,0 +1,516 @@ +/* + +Copyright 1996,2002,2005 Gregory D. Hager, Alfred A. Rizzi, Noah J. Cowan, + Jason Lapenta, Scott Smedley, Greg Sharp + +This file is part of the DT3155 Device Driver. + +The DT3155 Device Driver is free software; you can redistribute it +and/or modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The DT3155 Device Driver is distributed in the hope that it will be +useful, but WITHOUT ANY WARRANTY; without even the implied warranty +of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with the DT3155 Device Driver; if not, write to the Free +Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, +MA 02111-1307 USA + + File: dt3155_isr.c +Purpose: Buffer management routines, and other routines for the ISR + (the actual isr is in dt3155_drv.c) + +-- Changes -- + + Date Programmer Description of changes made + ------------------------------------------------------------------- + 03-Jul-2000 JML n/a + 02-Apr-2002 SS Mods to make work with separate allocator + module; Merged John Roll's mods to make work with + multiple boards. + 10-Jul-2002 GCS Complete rewrite of setup_buffers to disallow + buffers which span a 4MB boundary. + 24-Jul-2002 SS GPL licence. + 30-Jul-2002 NJC Added support for buffer loop. + 31-Jul-2002 NJC Complete rewrite of buffer management + 02-Aug-2002 NJC Including slab.h instead of malloc.h (no warning). + Also, allocator_init() now returns allocator_max + so cleaned up allocate_buffers() accordingly. + 08-Aug-2005 SS port to 2.6 kernel. + +*/ + +#include <asm/system.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/types.h> + +#include "dt3155.h" +#include "dt3155_drv.h" +#include "dt3155_io.h" +#include "dt3155_isr.h" +#include "allocator.h" + +#define FOUR_MB (0x0400000) /* Can't DMA accross a 4MB boundary!*/ +#define UPPER_10_BITS (0x3FF<<22) /* Can't DMA accross a 4MB boundary!*/ + + +/* Pointer into global structure for handling buffers */ +struct dt3155_fbuffer_s *dt3155_fbuffer[MAXBOARDS] = {NULL +#if MAXBOARDS == 2 + , NULL +#endif +}; + +/****************************************************************************** + * Simple array based que struct + * + * Some handy functions using the buffering structure. + *****************************************************************************/ + + +/*************************** + * are_empty_buffers + * m is minor # of device + ***************************/ +inline bool are_empty_buffers( int m ) +{ + return ( dt3155_fbuffer[ m ]->empty_len ); +} + +/************************** + * push_empty + * m is minor # of device + * + * This is slightly confusing. The number empty_len is the literal # + * of empty buffers. After calling, empty_len-1 is the index into the + * empty buffer stack. So, if empty_len == 1, there is one empty buffer, + * given by dt3155_fbuffer[m]->empty_buffers[0]. + * empty_buffers should never fill up, though this is not checked. + **************************/ +inline void push_empty( int index, int m ) +{ + dt3155_fbuffer[m]->empty_buffers[ dt3155_fbuffer[m]->empty_len ] = index; + dt3155_fbuffer[m]->empty_len++; +} + +/************************** + * pop_empty( m ) + * m is minor # of device + **************************/ +inline int pop_empty( int m ) +{ + dt3155_fbuffer[m]->empty_len--; + return dt3155_fbuffer[m]->empty_buffers[ dt3155_fbuffer[m]->empty_len ]; +} + +/************************* + * is_ready_buf_empty( m ) + * m is minor # of device + *************************/ +inline bool is_ready_buf_empty( int m ) +{ + return ((dt3155_fbuffer[ m ]->ready_len) == 0); +} + +/************************* + * is_ready_buf_full( m ) + * m is minor # of device + * this should *never* be true if there are any active, locked or empty + * buffers, since it corresponds to nbuffers ready buffers!! + * 7/31/02: total rewrite. --NJC + *************************/ +inline bool is_ready_buf_full( int m ) +{ + return ( dt3155_fbuffer[ m ]->ready_len == dt3155_fbuffer[ m ]->nbuffers ); +} + +/***************************************************** + * push_ready( m, buffer ) + * m is minor # of device + * + *****************************************************/ +inline void push_ready( int m, int index ) +{ + int head = dt3155_fbuffer[m]->ready_head; + + dt3155_fbuffer[ m ]->ready_que[ head ] = index; + dt3155_fbuffer[ m ]->ready_head = ( (head + 1) % + (dt3155_fbuffer[ m ]->nbuffers) ); + dt3155_fbuffer[ m ]->ready_len++; + +} + +/***************************************************** + * get_tail() + * m is minor # of device + * + * Simply comptutes the tail given the head and the length. + *****************************************************/ +static inline int get_tail( int m ) +{ + return ((dt3155_fbuffer[ m ]->ready_head - + dt3155_fbuffer[ m ]->ready_len + + dt3155_fbuffer[ m ]->nbuffers)% + (dt3155_fbuffer[ m ]->nbuffers)); +} + + + +/***************************************************** + * pop_ready() + * m is minor # of device + * + * This assumes that there is a ready buffer ready... should + * be checked (e.g. with is_ready_buf_empty() prior to call. + *****************************************************/ +inline int pop_ready( int m ) +{ + int tail; + tail = get_tail(m); + dt3155_fbuffer[ m ]->ready_len--; + return dt3155_fbuffer[ m ]->ready_que[ tail ]; +} + + +/***************************************************** + * printques + * m is minor # of device + *****************************************************/ +inline void printques( int m ) +{ + int head = dt3155_fbuffer[ m ]->ready_head; + int tail; + int num = dt3155_fbuffer[ m ]->nbuffers; + int frame_index; + int index; + + tail = get_tail(m); + + printk("\n R:"); + for ( index = tail; index != head; index++, index = index % (num) ) + { + frame_index = dt3155_fbuffer[ m ]->ready_que[ index ]; + printk(" %d ", frame_index ); + } + + printk("\n E:"); + for ( index = 0; index < dt3155_fbuffer[ m ]->empty_len; index++ ) + { + frame_index = dt3155_fbuffer[ m ]->empty_buffers[ index ]; + printk(" %d ", frame_index ); + } + + frame_index = dt3155_fbuffer[ m ]->active_buf; + printk("\n A: %d", frame_index); + + frame_index = dt3155_fbuffer[ m ]->locked_buf; + printk("\n L: %d \n", frame_index ); + +} + +/***************************************************** + * adjust_4MB + * + * If a buffer intersects the 4MB boundary, push + * the start address up to the beginning of the + * next 4MB chunk (assuming bufsize < 4MB). + *****************************************************/ +u32 adjust_4MB (u32 buf_addr, u32 bufsize) { + if (((buf_addr+bufsize) & UPPER_10_BITS) != (buf_addr & UPPER_10_BITS)) + return (buf_addr+bufsize) & UPPER_10_BITS; + else + return buf_addr; +} + + +/***************************************************** + * allocate_buffers + * + * Try to allocate enough memory for all requested + * buffers. If there is not enough free space + * try for less memory. + *****************************************************/ +void allocate_buffers (u32 *buf_addr, u32* total_size_kbs, + u32 bufsize) +{ + /* Compute the minimum amount of memory guaranteed to hold all + MAXBUFFERS such that no buffer crosses the 4MB boundary. + Store this value in the variable "full_size" */ + + u32 allocator_max; + u32 bufs_per_chunk = (FOUR_MB / bufsize); + u32 filled_chunks = (MAXBUFFERS-1) / bufs_per_chunk; + u32 leftover_bufs = MAXBUFFERS - filled_chunks * bufs_per_chunk; + + u32 full_size = bufsize /* possibly unusable part of 1st chunk */ + + filled_chunks * FOUR_MB /* max # of completely filled 4mb chunks */ + + leftover_bufs * bufsize; /* these buffs will be in a partly filled + chunk at beginning or end */ + + u32 full_size_kbs = 1 + (full_size-1) / 1024; + u32 min_size_kbs = 2*ndevices*bufsize / 1024; + u32 size_kbs; + + /* Now, try to allocate full_size. If this fails, keep trying for + less & less memory until it succeeds. */ +#ifndef STANDALONE_ALLOCATOR + /* initialize the allocator */ + allocator_init(&allocator_max); +#endif + size_kbs = full_size_kbs; + *buf_addr = 0; + printk("DT3155: We would like to get: %d KB\n", full_size_kbs); + printk("DT3155: ...but need at least: %d KB\n", min_size_kbs); + printk("DT3155: ...the allocator has: %d KB\n", allocator_max); + size_kbs = (full_size_kbs <= allocator_max ? full_size_kbs : allocator_max); + if (size_kbs > min_size_kbs) { + if ((*buf_addr = allocator_allocate_dma (size_kbs, GFP_KERNEL)) != 0) { + printk("DT3155: Managed to allocate: %d KB\n", size_kbs); + *total_size_kbs = size_kbs; + return; + } + } + /* If we got here, the allocation failed */ + printk ("DT3155: Allocator failed!\n"); + *buf_addr = 0; + *total_size_kbs = 0; + return; + +} + + +/***************************************************** + * dt3155_setup_buffers + * + * setup_buffers just puts the buffering system into + * a consistent state before the start of interrupts + * + * JML : it looks like all the buffers need to be + * continuous. So I'm going to try and allocate one + * continuous buffer. + * + * GCS : Fix DMA problems when buffer spans + * 4MB boundary. Also, add error checking. This + * function will return -ENOMEM when not enough memory. + *****************************************************/ +u32 dt3155_setup_buffers(u32 *allocatorAddr) + +{ + u32 index; + u32 rambuff_addr; /* start of allocation */ + u32 rambuff_size; /* total size allocated to driver */ + u32 rambuff_acm; /* accumlator, keep track of how much + is left after being split up*/ + u32 rambuff_end; /* end of rambuff */ + u32 numbufs; /* number of useful buffers allocated (per device) */ + u32 bufsize = DT3155_MAX_ROWS * DT3155_MAX_COLS; + int m; /* minor # of device, looped for all devs */ + + /* zero the fbuffer status and address structure */ + for ( m = 0; m < ndevices; m++) + { + dt3155_fbuffer[ m ] = &(dt3155_status[ m ].fbuffer); + + /* Make sure the buffering variables are consistent */ + { + u8 *ptr = (u8 *) dt3155_fbuffer[ m ]; + for( index = 0; index < sizeof(struct dt3155_fbuffer_s); index++) + *(ptr++)=0; + } + } + + /* allocate a large contiguous chunk of RAM */ + allocate_buffers (&rambuff_addr, &rambuff_size, bufsize); + printk("DT3155: mem info\n"); + printk(" - rambuf_addr = 0x%x \n", rambuff_addr); + printk(" - length (kb) = %u \n", rambuff_size); + if( rambuff_addr == 0 ) + { + printk( KERN_INFO + "DT3155: Error setup_buffers() allocator dma failed \n" ); + return -ENOMEM; + } + *allocatorAddr = rambuff_addr; + rambuff_end = rambuff_addr + 1024 * rambuff_size; + + /* after allocation, we need to count how many useful buffers there + are so we can give an equal number to each device */ + rambuff_acm = rambuff_addr; + for ( index = 0; index < MAXBUFFERS; index++) { + rambuff_acm = adjust_4MB (rambuff_acm, bufsize);/*avoid spanning 4MB bdry*/ + if (rambuff_acm + bufsize > rambuff_end) + break; + rambuff_acm += bufsize; + } + /* Following line is OK, will waste buffers if index + * not evenly divisible by ndevices -NJC*/ + numbufs = index / ndevices; + printk(" - numbufs = %u\n", numbufs); + if (numbufs < 2) { + printk( KERN_INFO + "DT3155: Error setup_buffers() couldn't allocate 2 bufs/board\n" ); + return -ENOMEM; + } + + /* now that we have board memory we spit it up */ + /* between the boards and the buffers */ + rambuff_acm = rambuff_addr; + for ( m = 0; m < ndevices; m ++) + { + rambuff_acm = adjust_4MB (rambuff_acm, bufsize); + + /* Save the start of this boards buffer space (for mmap). */ + dt3155_status[ m ].mem_addr = rambuff_acm; + + for (index = 0; index < numbufs; index++) + { + rambuff_acm = adjust_4MB (rambuff_acm, bufsize); + if (rambuff_acm + bufsize > rambuff_end) { + /* Should never happen */ + printk ("DT3155 PROGRAM ERROR (GCS)\n" + "Error distributing allocated buffers\n"); + return -ENOMEM; + } + + dt3155_fbuffer[ m ]->frame_info[ index ].addr = rambuff_acm; + push_empty( index, m ); + /* printk(" - Buffer : %lx\n", + * dt3155_fbuffer[ m ]->frame_info[ index ].addr ); + */ + dt3155_fbuffer[ m ]->nbuffers += 1; + rambuff_acm += bufsize; + } + + /* Make sure there is an active buffer there. */ + dt3155_fbuffer[ m ]->active_buf = pop_empty( m ); + dt3155_fbuffer[ m ]->even_happened = 0; + dt3155_fbuffer[ m ]->even_stopped = 0; + + /* make sure there is no locked_buf JML 2/28/00 */ + dt3155_fbuffer[ m ]->locked_buf = -1; + + dt3155_status[ m ].mem_size = + rambuff_acm - dt3155_status[ m ].mem_addr; + + /* setup the ready queue */ + dt3155_fbuffer[ m ]->ready_head = 0; + dt3155_fbuffer[ m ]->ready_len = 0; + printk("Available buffers for device %d: %d\n", + m, dt3155_fbuffer[ m ]->nbuffers); + } + + return 1; +} + +/***************************************************** + * internal_release_locked_buffer + * + * The internal function for releasing a locked buffer. + * It assumes interrupts are turned off. + * + * m is minor number of device + *****************************************************/ +static inline void internal_release_locked_buffer( int m ) +{ + /* Pointer into global structure for handling buffers */ + if ( dt3155_fbuffer[ m ]->locked_buf >= 0 ) + { + push_empty( dt3155_fbuffer[ m ]->locked_buf, m ); + dt3155_fbuffer[ m ]->locked_buf = -1; + } +} + + +/***************************************************** + * dt3155_release_locked_buffer() + * m is minor # of device + * + * The user function of the above. + * + *****************************************************/ +inline void dt3155_release_locked_buffer( int m ) +{ + unsigned long int flags; + local_save_flags(flags); + local_irq_disable(); + internal_release_locked_buffer(m); + local_irq_restore(flags); +} + + +/***************************************************** + * dt3155_flush() + * m is minor # of device + * + *****************************************************/ +inline int dt3155_flush( int m ) +{ + int index; + unsigned long int flags; + local_save_flags(flags); + local_irq_disable(); + + internal_release_locked_buffer( m ); + dt3155_fbuffer[ m ]->empty_len = 0; + + for ( index = 0; index < dt3155_fbuffer[ m ]->nbuffers; index++ ) + push_empty( index, m ); + + /* Make sure there is an active buffer there. */ + dt3155_fbuffer[ m ]->active_buf = pop_empty( m ); + + dt3155_fbuffer[ m ]->even_happened = 0; + dt3155_fbuffer[ m ]->even_stopped = 0; + + /* setup the ready queue */ + dt3155_fbuffer[ m ]->ready_head = 0; + dt3155_fbuffer[ m ]->ready_len = 0; + + local_irq_restore(flags); + + return 0; +} + +/***************************************************** + * dt3155_get_ready_buffer() + * m is minor # of device + * + * get_ready_buffer will grab the next chunk of data + * if it is already there, otherwise it returns 0. + * If the user has a buffer locked it will unlock + * that buffer before returning the new one. + *****************************************************/ +inline int dt3155_get_ready_buffer( int m ) +{ + int frame_index; + unsigned long int flags; + local_save_flags(flags); + local_irq_disable(); + +#ifdef DEBUG_QUES_A + printques( m ); +#endif + + internal_release_locked_buffer( m ); + + if (is_ready_buf_empty( m )) + frame_index = -1; + else + { + frame_index = pop_ready( m ); + dt3155_fbuffer[ m ]->locked_buf = frame_index; + } + +#ifdef DEBUG_QUES_B + printques( m ); +#endif + + local_irq_restore(flags); + + return frame_index; +} |