906 строки
27 KiB
C
906 строки
27 KiB
C
/*
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* atari_scsi.c -- Device dependent functions for the Atari generic SCSI port
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*
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* Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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*
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* Loosely based on the work of Robert De Vries' team and added:
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* - working real DMA
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* - Falcon support (untested yet!) ++bjoern fixed and now it works
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* - lots of extensions and bug fixes.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*
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*/
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/*
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* Notes for Falcon SCSI DMA
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*
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* The 5380 device is one of several that all share the DMA chip. Hence
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* "locking" and "unlocking" access to this chip is required.
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*
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* Two possible schemes for ST DMA acquisition by atari_scsi are:
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* 1) The lock is taken for each command separately (i.e. can_queue == 1).
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* 2) The lock is taken when the first command arrives and released
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* when the last command is finished (i.e. can_queue > 1).
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*
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* The first alternative limits SCSI bus utilization, since interleaving
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* commands is not possible. The second gives better performance but is
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* unfair to other drivers needing to use the ST DMA chip. In order to
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* allow the IDE and floppy drivers equal access to the ST DMA chip
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* the default is can_queue == 1.
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/blkdev.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/nvram.h>
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#include <linux/bitops.h>
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#include <linux/wait.h>
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#include <linux/platform_device.h>
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#include <asm/setup.h>
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#include <asm/atarihw.h>
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#include <asm/atariints.h>
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#include <asm/atari_stdma.h>
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#include <asm/atari_stram.h>
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#include <asm/io.h>
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#include <scsi/scsi_host.h>
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#define DMA_MIN_SIZE 32
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/* Definitions for the core NCR5380 driver. */
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#define NCR5380_implementation_fields /* none */
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#define NCR5380_read(reg) atari_scsi_reg_read(reg)
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#define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)
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#define NCR5380_queue_command atari_scsi_queue_command
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#define NCR5380_abort atari_scsi_abort
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#define NCR5380_info atari_scsi_info
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#define NCR5380_dma_recv_setup(instance, data, count) \
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atari_scsi_dma_setup(instance, data, count, 0)
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#define NCR5380_dma_send_setup(instance, data, count) \
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atari_scsi_dma_setup(instance, data, count, 1)
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#define NCR5380_dma_residual(instance) \
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atari_scsi_dma_residual(instance)
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#define NCR5380_dma_xfer_len(instance, cmd, phase) \
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atari_dma_xfer_len(cmd->SCp.this_residual, cmd, !((phase) & SR_IO))
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#define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)
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#define NCR5380_release_dma_irq(instance) falcon_release_lock()
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#include "NCR5380.h"
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#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
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#define SCSI_DMA_WRITE_P(elt,val) \
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do { \
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unsigned long v = val; \
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tt_scsi_dma.elt##_lo = v & 0xff; \
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v >>= 8; \
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tt_scsi_dma.elt##_lmd = v & 0xff; \
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v >>= 8; \
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tt_scsi_dma.elt##_hmd = v & 0xff; \
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v >>= 8; \
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tt_scsi_dma.elt##_hi = v & 0xff; \
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} while(0)
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#define SCSI_DMA_READ_P(elt) \
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(((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
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(unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
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(unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
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(unsigned long)tt_scsi_dma.elt##_lo)
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static inline void SCSI_DMA_SETADR(unsigned long adr)
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{
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st_dma.dma_lo = (unsigned char)adr;
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MFPDELAY();
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adr >>= 8;
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st_dma.dma_md = (unsigned char)adr;
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MFPDELAY();
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adr >>= 8;
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st_dma.dma_hi = (unsigned char)adr;
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MFPDELAY();
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}
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static inline unsigned long SCSI_DMA_GETADR(void)
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{
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unsigned long adr;
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adr = st_dma.dma_lo;
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MFPDELAY();
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adr |= (st_dma.dma_md & 0xff) << 8;
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MFPDELAY();
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adr |= (st_dma.dma_hi & 0xff) << 16;
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MFPDELAY();
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return adr;
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}
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static void atari_scsi_fetch_restbytes(void);
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static unsigned char (*atari_scsi_reg_read)(unsigned char reg);
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static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value);
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static unsigned long atari_dma_residual, atari_dma_startaddr;
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static short atari_dma_active;
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/* pointer to the dribble buffer */
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static char *atari_dma_buffer;
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/* precalculated physical address of the dribble buffer */
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static unsigned long atari_dma_phys_buffer;
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/* != 0 tells the Falcon int handler to copy data from the dribble buffer */
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static char *atari_dma_orig_addr;
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/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
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* scatter-gather anyway, so most transfers are 1024 byte only. In the rare
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* cases where requests to physical contiguous buffers have been merged, this
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* request is <= 4k (one page). So I don't think we have to split transfers
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* just due to this buffer size...
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*/
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#define STRAM_BUFFER_SIZE (4096)
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/* mask for address bits that can't be used with the ST-DMA */
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static unsigned long atari_dma_stram_mask;
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#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
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static int setup_can_queue = -1;
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module_param(setup_can_queue, int, 0);
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static int setup_cmd_per_lun = -1;
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module_param(setup_cmd_per_lun, int, 0);
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static int setup_sg_tablesize = -1;
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module_param(setup_sg_tablesize, int, 0);
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static int setup_hostid = -1;
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module_param(setup_hostid, int, 0);
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static int setup_toshiba_delay = -1;
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module_param(setup_toshiba_delay, int, 0);
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static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
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{
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int i;
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unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
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if (dma_stat & 0x01) {
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/* A bus error happens when DMA-ing from the last page of a
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* physical memory chunk (DMA prefetch!), but that doesn't hurt.
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* Check for this case:
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*/
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for (i = 0; i < m68k_num_memory; ++i) {
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end_addr = m68k_memory[i].addr + m68k_memory[i].size;
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if (end_addr <= addr && addr <= end_addr + 4)
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return 1;
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}
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}
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return 0;
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}
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#if 0
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/* Dead code... wasn't called anyway :-) and causes some trouble, because at
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* end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
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* to clear the DMA int pending bit before it allows other level 6 interrupts.
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*/
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static void scsi_dma_buserr(int irq, void *dummy)
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{
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unsigned char dma_stat = tt_scsi_dma.dma_ctrl;
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/* Don't do anything if a NCR interrupt is pending. Probably it's just
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* masked... */
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if (atari_irq_pending(IRQ_TT_MFP_SCSI))
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return;
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printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
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SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt));
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if (dma_stat & 0x80) {
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if (!scsi_dma_is_ignored_buserr(dma_stat))
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printk("SCSI DMA bus error -- bad DMA programming!\n");
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} else {
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/* Under normal circumstances we never should get to this point,
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* since both interrupts are triggered simultaneously and the 5380
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* int has higher priority. When this irq is handled, that DMA
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* interrupt is cleared. So a warning message is printed here.
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*/
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printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
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}
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}
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#endif
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static irqreturn_t scsi_tt_intr(int irq, void *dev)
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{
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struct Scsi_Host *instance = dev;
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struct NCR5380_hostdata *hostdata = shost_priv(instance);
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int dma_stat;
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dma_stat = tt_scsi_dma.dma_ctrl;
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dsprintk(NDEBUG_INTR, instance, "NCR5380 interrupt, DMA status = %02x\n",
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dma_stat & 0xff);
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/* Look if it was the DMA that has interrupted: First possibility
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* is that a bus error occurred...
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*/
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if (dma_stat & 0x80) {
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if (!scsi_dma_is_ignored_buserr(dma_stat)) {
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printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
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SCSI_DMA_READ_P(dma_addr));
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printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
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}
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}
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/* If the DMA is active but not finished, we have the case
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* that some other 5380 interrupt occurred within the DMA transfer.
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* This means we have residual bytes, if the desired end address
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* is not yet reached. Maybe we have to fetch some bytes from the
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* rest data register, too. The residual must be calculated from
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* the address pointer, not the counter register, because only the
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* addr reg counts bytes not yet written and pending in the rest
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* data reg!
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*/
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if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
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atari_dma_residual = hostdata->dma_len -
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(SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
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dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
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atari_dma_residual);
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if ((signed int)atari_dma_residual < 0)
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atari_dma_residual = 0;
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if ((dma_stat & 1) == 0) {
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/*
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* After read operations, we maybe have to
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* transport some rest bytes
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*/
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atari_scsi_fetch_restbytes();
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} else {
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/*
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* There seems to be a nasty bug in some SCSI-DMA/NCR
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* combinations: If a target disconnects while a write
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* operation is going on, the address register of the
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* DMA may be a few bytes farer than it actually read.
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* This is probably due to DMA prefetching and a delay
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* between DMA and NCR. Experiments showed that the
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* dma_addr is 9 bytes to high, but this could vary.
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* The problem is, that the residual is thus calculated
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* wrong and the next transfer will start behind where
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* it should. So we round up the residual to the next
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* multiple of a sector size, if it isn't already a
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* multiple and the originally expected transfer size
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* was. The latter condition is there to ensure that
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* the correction is taken only for "real" data
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* transfers and not for, e.g., the parameters of some
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* other command. These shouldn't disconnect anyway.
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*/
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if (atari_dma_residual & 0x1ff) {
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dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, "
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"difference %ld bytes\n",
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512 - (atari_dma_residual & 0x1ff));
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atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
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}
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}
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tt_scsi_dma.dma_ctrl = 0;
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}
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/* If the DMA is finished, fetch the rest bytes and turn it off */
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if (dma_stat & 0x40) {
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atari_dma_residual = 0;
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if ((dma_stat & 1) == 0)
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atari_scsi_fetch_restbytes();
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tt_scsi_dma.dma_ctrl = 0;
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}
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NCR5380_intr(irq, dev);
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return IRQ_HANDLED;
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}
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static irqreturn_t scsi_falcon_intr(int irq, void *dev)
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{
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struct Scsi_Host *instance = dev;
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struct NCR5380_hostdata *hostdata = shost_priv(instance);
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int dma_stat;
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/* Turn off DMA and select sector counter register before
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* accessing the status register (Atari recommendation!)
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*/
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st_dma.dma_mode_status = 0x90;
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dma_stat = st_dma.dma_mode_status;
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/* Bit 0 indicates some error in the DMA process... don't know
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* what happened exactly (no further docu).
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*/
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if (!(dma_stat & 0x01)) {
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/* DMA error */
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printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
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}
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/* If the DMA was active, but now bit 1 is not clear, it is some
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* other 5380 interrupt that finishes the DMA transfer. We have to
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* calculate the number of residual bytes and give a warning if
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* bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
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*/
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if (atari_dma_active && (dma_stat & 0x02)) {
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unsigned long transferred;
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transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
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/* The ST-DMA address is incremented in 2-byte steps, but the
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* data are written only in 16-byte chunks. If the number of
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* transferred bytes is not divisible by 16, the remainder is
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* lost somewhere in outer space.
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*/
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if (transferred & 15)
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printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
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"ST-DMA fifo\n", transferred & 15);
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atari_dma_residual = hostdata->dma_len - transferred;
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dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
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atari_dma_residual);
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} else
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atari_dma_residual = 0;
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atari_dma_active = 0;
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if (atari_dma_orig_addr) {
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/* If the dribble buffer was used on a read operation, copy the DMA-ed
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* data to the original destination address.
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*/
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memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
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hostdata->dma_len - atari_dma_residual);
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atari_dma_orig_addr = NULL;
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}
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NCR5380_intr(irq, dev);
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return IRQ_HANDLED;
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}
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static void atari_scsi_fetch_restbytes(void)
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{
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int nr;
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char *src, *dst;
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unsigned long phys_dst;
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/* fetch rest bytes in the DMA register */
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phys_dst = SCSI_DMA_READ_P(dma_addr);
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nr = phys_dst & 3;
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if (nr) {
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/* there are 'nr' bytes left for the last long address
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before the DMA pointer */
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phys_dst ^= nr;
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dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
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nr, phys_dst);
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/* The content of the DMA pointer is a physical address! */
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dst = phys_to_virt(phys_dst);
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dprintk(NDEBUG_DMA, " = virt addr %p\n", dst);
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for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
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*dst++ = *src++;
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}
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}
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/* This function releases the lock on the DMA chip if there is no
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* connected command and the disconnected queue is empty.
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*/
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static void falcon_release_lock(void)
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{
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if (IS_A_TT())
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return;
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if (stdma_is_locked_by(scsi_falcon_intr))
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stdma_release();
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}
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/* This function manages the locking of the ST-DMA.
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* If the DMA isn't locked already for SCSI, it tries to lock it by
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* calling stdma_lock(). But if the DMA is locked by the SCSI code and
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* there are other drivers waiting for the chip, we do not issue the
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* command immediately but tell the SCSI mid-layer to defer.
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*/
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static int falcon_get_lock(struct Scsi_Host *instance)
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{
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if (IS_A_TT())
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return 1;
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if (stdma_is_locked_by(scsi_falcon_intr) &&
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instance->hostt->can_queue > 1)
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return 1;
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if (in_interrupt())
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return stdma_try_lock(scsi_falcon_intr, instance);
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stdma_lock(scsi_falcon_intr, instance);
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return 1;
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}
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#ifndef MODULE
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static int __init atari_scsi_setup(char *str)
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{
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/* Format of atascsi parameter is:
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* atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
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* Defaults depend on TT or Falcon, determined at run time.
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* Negative values mean don't change.
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*/
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int ints[8];
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get_options(str, ARRAY_SIZE(ints), ints);
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if (ints[0] < 1) {
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printk("atari_scsi_setup: no arguments!\n");
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return 0;
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}
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if (ints[0] >= 1)
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setup_can_queue = ints[1];
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if (ints[0] >= 2)
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setup_cmd_per_lun = ints[2];
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if (ints[0] >= 3)
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setup_sg_tablesize = ints[3];
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if (ints[0] >= 4)
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setup_hostid = ints[4];
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/* ints[5] (use_tagged_queuing) is ignored */
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/* ints[6] (use_pdma) is ignored */
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if (ints[0] >= 7)
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setup_toshiba_delay = ints[7];
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return 1;
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}
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__setup("atascsi=", atari_scsi_setup);
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#endif /* !MODULE */
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static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance,
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void *data, unsigned long count,
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int dir)
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{
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unsigned long addr = virt_to_phys(data);
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dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
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"dir = %d\n", instance->host_no, data, addr, count, dir);
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if (!IS_A_TT() && !STRAM_ADDR(addr)) {
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/* If we have a non-DMAable address on a Falcon, use the dribble
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* buffer; 'orig_addr' != 0 in the read case tells the interrupt
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* handler to copy data from the dribble buffer to the originally
|
|
* wanted address.
|
|
*/
|
|
if (dir)
|
|
memcpy(atari_dma_buffer, data, count);
|
|
else
|
|
atari_dma_orig_addr = data;
|
|
addr = atari_dma_phys_buffer;
|
|
}
|
|
|
|
atari_dma_startaddr = addr; /* Needed for calculating residual later. */
|
|
|
|
/* Cache cleanup stuff: On writes, push any dirty cache out before sending
|
|
* it to the peripheral. (Must be done before DMA setup, since at least
|
|
* the ST-DMA begins to fill internal buffers right after setup. For
|
|
* reads, invalidate any cache, may be altered after DMA without CPU
|
|
* knowledge.
|
|
*
|
|
* ++roman: For the Medusa, there's no need at all for that cache stuff,
|
|
* because the hardware does bus snooping (fine!).
|
|
*/
|
|
dma_cache_maintenance(addr, count, dir);
|
|
|
|
if (IS_A_TT()) {
|
|
tt_scsi_dma.dma_ctrl = dir;
|
|
SCSI_DMA_WRITE_P(dma_addr, addr);
|
|
SCSI_DMA_WRITE_P(dma_cnt, count);
|
|
tt_scsi_dma.dma_ctrl = dir | 2;
|
|
} else { /* ! IS_A_TT */
|
|
|
|
/* set address */
|
|
SCSI_DMA_SETADR(addr);
|
|
|
|
/* toggle direction bit to clear FIFO and set DMA direction */
|
|
dir <<= 8;
|
|
st_dma.dma_mode_status = 0x90 | dir;
|
|
st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
|
|
st_dma.dma_mode_status = 0x90 | dir;
|
|
udelay(40);
|
|
/* On writes, round up the transfer length to the next multiple of 512
|
|
* (see also comment at atari_dma_xfer_len()). */
|
|
st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
|
|
udelay(40);
|
|
st_dma.dma_mode_status = 0x10 | dir;
|
|
udelay(40);
|
|
/* need not restore value of dir, only boolean value is tested */
|
|
atari_dma_active = 1;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
|
|
static long atari_scsi_dma_residual(struct Scsi_Host *instance)
|
|
{
|
|
return atari_dma_residual;
|
|
}
|
|
|
|
|
|
#define CMD_SURELY_BLOCK_MODE 0
|
|
#define CMD_SURELY_BYTE_MODE 1
|
|
#define CMD_MODE_UNKNOWN 2
|
|
|
|
static int falcon_classify_cmd(struct scsi_cmnd *cmd)
|
|
{
|
|
unsigned char opcode = cmd->cmnd[0];
|
|
|
|
if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
|
|
opcode == READ_BUFFER)
|
|
return CMD_SURELY_BYTE_MODE;
|
|
else if (opcode == READ_6 || opcode == READ_10 ||
|
|
opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
|
|
opcode == RECOVER_BUFFERED_DATA) {
|
|
/* In case of a sequential-access target (tape), special care is
|
|
* needed here: The transfer is block-mode only if the 'fixed' bit is
|
|
* set! */
|
|
if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
|
|
return CMD_SURELY_BYTE_MODE;
|
|
else
|
|
return CMD_SURELY_BLOCK_MODE;
|
|
} else
|
|
return CMD_MODE_UNKNOWN;
|
|
}
|
|
|
|
|
|
/* This function calculates the number of bytes that can be transferred via
|
|
* DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
|
|
* ST-DMA chip. There are only multiples of 512 bytes possible and max.
|
|
* 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
|
|
* possible on the Falcon, since that would require to program the DMA for
|
|
* n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
|
|
* the overrun problem, so this question is academic :-)
|
|
*/
|
|
|
|
static unsigned long atari_dma_xfer_len(unsigned long wanted_len,
|
|
struct scsi_cmnd *cmd, int write_flag)
|
|
{
|
|
unsigned long possible_len, limit;
|
|
|
|
if (wanted_len < DMA_MIN_SIZE)
|
|
return 0;
|
|
|
|
if (IS_A_TT())
|
|
/* TT SCSI DMA can transfer arbitrary #bytes */
|
|
return wanted_len;
|
|
|
|
/* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
|
|
* 255*512 bytes, but this should be enough)
|
|
*
|
|
* ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
|
|
* that return a number of bytes which cannot be known beforehand. In this
|
|
* case, the given transfer length is an "allocation length". Now it
|
|
* can happen that this allocation length is a multiple of 512 bytes and
|
|
* the DMA is used. But if not n*512 bytes really arrive, some input data
|
|
* will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
|
|
* between commands that do block transfers and those that do byte
|
|
* transfers. But this isn't easy... there are lots of vendor specific
|
|
* commands, and the user can issue any command via the
|
|
* SCSI_IOCTL_SEND_COMMAND.
|
|
*
|
|
* The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
|
|
* 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
|
|
* and 3), the thing to do is obvious: allow any number of blocks via DMA
|
|
* or none. In case 2), we apply some heuristic: Byte mode is assumed if
|
|
* the transfer (allocation) length is < 1024, hoping that no cmd. not
|
|
* explicitly known as byte mode have such big allocation lengths...
|
|
* BTW, all the discussion above applies only to reads. DMA writes are
|
|
* unproblematic anyways, since the targets aborts the transfer after
|
|
* receiving a sufficient number of bytes.
|
|
*
|
|
* Another point: If the transfer is from/to an non-ST-RAM address, we
|
|
* use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
|
|
*/
|
|
|
|
if (write_flag) {
|
|
/* Write operation can always use the DMA, but the transfer size must
|
|
* be rounded up to the next multiple of 512 (atari_dma_setup() does
|
|
* this).
|
|
*/
|
|
possible_len = wanted_len;
|
|
} else {
|
|
/* Read operations: if the wanted transfer length is not a multiple of
|
|
* 512, we cannot use DMA, since the ST-DMA cannot split transfers
|
|
* (no interrupt on DMA finished!)
|
|
*/
|
|
if (wanted_len & 0x1ff)
|
|
possible_len = 0;
|
|
else {
|
|
/* Now classify the command (see above) and decide whether it is
|
|
* allowed to do DMA at all */
|
|
switch (falcon_classify_cmd(cmd)) {
|
|
case CMD_SURELY_BLOCK_MODE:
|
|
possible_len = wanted_len;
|
|
break;
|
|
case CMD_SURELY_BYTE_MODE:
|
|
possible_len = 0; /* DMA prohibited */
|
|
break;
|
|
case CMD_MODE_UNKNOWN:
|
|
default:
|
|
/* For unknown commands assume block transfers if the transfer
|
|
* size/allocation length is >= 1024 */
|
|
possible_len = (wanted_len < 1024) ? 0 : wanted_len;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Last step: apply the hard limit on DMA transfers */
|
|
limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
|
|
STRAM_BUFFER_SIZE : 255*512;
|
|
if (possible_len > limit)
|
|
possible_len = limit;
|
|
|
|
if (possible_len != wanted_len)
|
|
dprintk(NDEBUG_DMA, "Sorry, must cut DMA transfer size to %ld bytes "
|
|
"instead of %ld\n", possible_len, wanted_len);
|
|
|
|
return possible_len;
|
|
}
|
|
|
|
|
|
/* NCR5380 register access functions
|
|
*
|
|
* There are separate functions for TT and Falcon, because the access
|
|
* methods are quite different. The calling macros NCR5380_read and
|
|
* NCR5380_write call these functions via function pointers.
|
|
*/
|
|
|
|
static unsigned char atari_scsi_tt_reg_read(unsigned char reg)
|
|
{
|
|
return tt_scsi_regp[reg * 2];
|
|
}
|
|
|
|
static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
|
|
{
|
|
tt_scsi_regp[reg * 2] = value;
|
|
}
|
|
|
|
static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
|
|
{
|
|
dma_wd.dma_mode_status= (u_short)(0x88 + reg);
|
|
return (u_char)dma_wd.fdc_acces_seccount;
|
|
}
|
|
|
|
static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
|
|
{
|
|
dma_wd.dma_mode_status = (u_short)(0x88 + reg);
|
|
dma_wd.fdc_acces_seccount = (u_short)value;
|
|
}
|
|
|
|
|
|
#include "NCR5380.c"
|
|
|
|
static int atari_scsi_bus_reset(struct scsi_cmnd *cmd)
|
|
{
|
|
int rv;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
|
|
/* Abort a maybe active DMA transfer */
|
|
if (IS_A_TT()) {
|
|
tt_scsi_dma.dma_ctrl = 0;
|
|
} else {
|
|
st_dma.dma_mode_status = 0x90;
|
|
atari_dma_active = 0;
|
|
atari_dma_orig_addr = NULL;
|
|
}
|
|
|
|
rv = NCR5380_bus_reset(cmd);
|
|
|
|
/* The 5380 raises its IRQ line while _RST is active but the ST DMA
|
|
* "lock" has been released so this interrupt may end up handled by
|
|
* floppy or IDE driver (if one of them holds the lock). The NCR5380
|
|
* interrupt flag has been cleared already.
|
|
*/
|
|
|
|
local_irq_restore(flags);
|
|
|
|
return rv;
|
|
}
|
|
|
|
#define DRV_MODULE_NAME "atari_scsi"
|
|
#define PFX DRV_MODULE_NAME ": "
|
|
|
|
static struct scsi_host_template atari_scsi_template = {
|
|
.module = THIS_MODULE,
|
|
.proc_name = DRV_MODULE_NAME,
|
|
.name = "Atari native SCSI",
|
|
.info = atari_scsi_info,
|
|
.queuecommand = atari_scsi_queue_command,
|
|
.eh_abort_handler = atari_scsi_abort,
|
|
.eh_bus_reset_handler = atari_scsi_bus_reset,
|
|
.this_id = 7,
|
|
.cmd_per_lun = 2,
|
|
.use_clustering = DISABLE_CLUSTERING,
|
|
.cmd_size = NCR5380_CMD_SIZE,
|
|
};
|
|
|
|
static int __init atari_scsi_probe(struct platform_device *pdev)
|
|
{
|
|
struct Scsi_Host *instance;
|
|
int error;
|
|
struct resource *irq;
|
|
int host_flags = 0;
|
|
|
|
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
|
|
if (!irq)
|
|
return -ENODEV;
|
|
|
|
if (ATARIHW_PRESENT(TT_SCSI)) {
|
|
atari_scsi_reg_read = atari_scsi_tt_reg_read;
|
|
atari_scsi_reg_write = atari_scsi_tt_reg_write;
|
|
} else {
|
|
atari_scsi_reg_read = atari_scsi_falcon_reg_read;
|
|
atari_scsi_reg_write = atari_scsi_falcon_reg_write;
|
|
}
|
|
|
|
if (ATARIHW_PRESENT(TT_SCSI)) {
|
|
atari_scsi_template.can_queue = 16;
|
|
atari_scsi_template.sg_tablesize = SG_ALL;
|
|
} else {
|
|
atari_scsi_template.can_queue = 1;
|
|
atari_scsi_template.sg_tablesize = SG_NONE;
|
|
}
|
|
|
|
if (setup_can_queue > 0)
|
|
atari_scsi_template.can_queue = setup_can_queue;
|
|
|
|
if (setup_cmd_per_lun > 0)
|
|
atari_scsi_template.cmd_per_lun = setup_cmd_per_lun;
|
|
|
|
/* Leave sg_tablesize at 0 on a Falcon! */
|
|
if (ATARIHW_PRESENT(TT_SCSI) && setup_sg_tablesize >= 0)
|
|
atari_scsi_template.sg_tablesize = setup_sg_tablesize;
|
|
|
|
if (setup_hostid >= 0) {
|
|
atari_scsi_template.this_id = setup_hostid & 7;
|
|
} else {
|
|
/* Test if a host id is set in the NVRam */
|
|
if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
|
|
unsigned char b = nvram_read_byte(16);
|
|
|
|
/* Arbitration enabled? (for TOS)
|
|
* If yes, use configured host ID
|
|
*/
|
|
if (b & 0x80)
|
|
atari_scsi_template.this_id = b & 7;
|
|
}
|
|
}
|
|
|
|
/* If running on a Falcon and if there's TT-Ram (i.e., more than one
|
|
* memory block, since there's always ST-Ram in a Falcon), then
|
|
* allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers
|
|
* from/to alternative Ram.
|
|
*/
|
|
if (ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(EXTD_DMA) &&
|
|
m68k_num_memory > 1) {
|
|
atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
|
|
if (!atari_dma_buffer) {
|
|
pr_err(PFX "can't allocate ST-RAM double buffer\n");
|
|
return -ENOMEM;
|
|
}
|
|
atari_dma_phys_buffer = atari_stram_to_phys(atari_dma_buffer);
|
|
atari_dma_orig_addr = 0;
|
|
}
|
|
|
|
instance = scsi_host_alloc(&atari_scsi_template,
|
|
sizeof(struct NCR5380_hostdata));
|
|
if (!instance) {
|
|
error = -ENOMEM;
|
|
goto fail_alloc;
|
|
}
|
|
|
|
instance->irq = irq->start;
|
|
|
|
host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;
|
|
host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
|
|
|
|
error = NCR5380_init(instance, host_flags);
|
|
if (error)
|
|
goto fail_init;
|
|
|
|
if (IS_A_TT()) {
|
|
error = request_irq(instance->irq, scsi_tt_intr, 0,
|
|
"NCR5380", instance);
|
|
if (error) {
|
|
pr_err(PFX "request irq %d failed, aborting\n",
|
|
instance->irq);
|
|
goto fail_irq;
|
|
}
|
|
tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
|
|
|
|
tt_scsi_dma.dma_ctrl = 0;
|
|
atari_dma_residual = 0;
|
|
|
|
/* While the read overruns (described by Drew Eckhardt in
|
|
* NCR5380.c) never happened on TTs, they do in fact on the
|
|
* Medusa (This was the cause why SCSI didn't work right for
|
|
* so long there.) Since handling the overruns slows down
|
|
* a bit, I turned the #ifdef's into a runtime condition.
|
|
*
|
|
* In principle it should be sufficient to do max. 1 byte with
|
|
* PIO, but there is another problem on the Medusa with the DMA
|
|
* rest data register. So read_overruns is currently set
|
|
* to 4 to avoid having transfers that aren't a multiple of 4.
|
|
* If the rest data bug is fixed, this can be lowered to 1.
|
|
*/
|
|
if (MACH_IS_MEDUSA) {
|
|
struct NCR5380_hostdata *hostdata =
|
|
shost_priv(instance);
|
|
|
|
hostdata->read_overruns = 4;
|
|
}
|
|
} else {
|
|
/* Nothing to do for the interrupt: the ST-DMA is initialized
|
|
* already.
|
|
*/
|
|
atari_dma_residual = 0;
|
|
atari_dma_active = 0;
|
|
atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
|
|
: 0xff000000);
|
|
}
|
|
|
|
NCR5380_maybe_reset_bus(instance);
|
|
|
|
error = scsi_add_host(instance, NULL);
|
|
if (error)
|
|
goto fail_host;
|
|
|
|
platform_set_drvdata(pdev, instance);
|
|
|
|
scsi_scan_host(instance);
|
|
return 0;
|
|
|
|
fail_host:
|
|
if (IS_A_TT())
|
|
free_irq(instance->irq, instance);
|
|
fail_irq:
|
|
NCR5380_exit(instance);
|
|
fail_init:
|
|
scsi_host_put(instance);
|
|
fail_alloc:
|
|
if (atari_dma_buffer)
|
|
atari_stram_free(atari_dma_buffer);
|
|
return error;
|
|
}
|
|
|
|
static int __exit atari_scsi_remove(struct platform_device *pdev)
|
|
{
|
|
struct Scsi_Host *instance = platform_get_drvdata(pdev);
|
|
|
|
scsi_remove_host(instance);
|
|
if (IS_A_TT())
|
|
free_irq(instance->irq, instance);
|
|
NCR5380_exit(instance);
|
|
scsi_host_put(instance);
|
|
if (atari_dma_buffer)
|
|
atari_stram_free(atari_dma_buffer);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver atari_scsi_driver = {
|
|
.remove = __exit_p(atari_scsi_remove),
|
|
.driver = {
|
|
.name = DRV_MODULE_NAME,
|
|
},
|
|
};
|
|
|
|
module_platform_driver_probe(atari_scsi_driver, atari_scsi_probe);
|
|
|
|
MODULE_ALIAS("platform:" DRV_MODULE_NAME);
|
|
MODULE_LICENSE("GPL");
|