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ide: add ide_read_bcount_and_ireason() helper
[linux-2.6-omap-h63xx.git] / drivers / ide / ide-atapi.c
1 /*
2  * ATAPI support.
3  */
4
5 #include <linux/kernel.h>
6 #include <linux/delay.h>
7 #include <linux/ide.h>
8 #include <scsi/scsi.h>
9
10 #ifdef DEBUG
11 #define debug_log(fmt, args...) \
12         printk(KERN_INFO "ide: " fmt, ## args)
13 #else
14 #define debug_log(fmt, args...) do {} while (0)
15 #endif
16
17 /* TODO: unify the code thus making some arguments go away */
18 ide_startstop_t ide_pc_intr(ide_drive_t *drive, struct ide_atapi_pc *pc,
19         ide_handler_t *handler, unsigned int timeout, ide_expiry_t *expiry,
20         void (*update_buffers)(ide_drive_t *, struct ide_atapi_pc *),
21         void (*retry_pc)(ide_drive_t *), void (*dsc_handle)(ide_drive_t *),
22         void (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
23 {
24         ide_hwif_t *hwif = drive->hwif;
25         xfer_func_t *xferfunc;
26         unsigned int temp;
27         u16 bcount;
28         u8 stat, ireason, scsi = drive->scsi;
29
30         debug_log("Enter %s - interrupt handler\n", __func__);
31
32         if (pc->flags & PC_FLAG_TIMEDOUT) {
33                 pc->callback(drive);
34                 return ide_stopped;
35         }
36
37         /* Clear the interrupt */
38         stat = hwif->read_status(hwif);
39
40         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
41                 if (hwif->dma_ops->dma_end(drive) ||
42                     (drive->media == ide_tape && !scsi && (stat & ERR_STAT))) {
43                         if (drive->media == ide_floppy && !scsi)
44                                 printk(KERN_ERR "%s: DMA %s error\n",
45                                         drive->name, rq_data_dir(pc->rq)
46                                                      ? "write" : "read");
47                         pc->flags |= PC_FLAG_DMA_ERROR;
48                 } else {
49                         pc->xferred = pc->req_xfer;
50                         if (update_buffers)
51                                 update_buffers(drive, pc);
52                 }
53                 debug_log("%s: DMA finished\n", drive->name);
54         }
55
56         /* No more interrupts */
57         if ((stat & DRQ_STAT) == 0) {
58                 debug_log("Packet command completed, %d bytes transferred\n",
59                           pc->xferred);
60
61                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
62
63                 local_irq_enable_in_hardirq();
64
65                 if (drive->media == ide_tape && !scsi &&
66                     (stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
67                         stat &= ~ERR_STAT;
68                 if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) {
69                         /* Error detected */
70                         debug_log("%s: I/O error\n", drive->name);
71
72                         if (drive->media != ide_tape || scsi) {
73                                 pc->rq->errors++;
74                                 if (scsi)
75                                         goto cmd_finished;
76                         }
77
78                         if (pc->c[0] == REQUEST_SENSE) {
79                                 printk(KERN_ERR "%s: I/O error in request sense"
80                                                 " command\n", drive->name);
81                                 return ide_do_reset(drive);
82                         }
83
84                         debug_log("[cmd %x]: check condition\n", pc->c[0]);
85
86                         /* Retry operation */
87                         retry_pc(drive);
88                         /* queued, but not started */
89                         return ide_stopped;
90                 }
91 cmd_finished:
92                 pc->error = 0;
93                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) &&
94                     (stat & SEEK_STAT) == 0) {
95                         dsc_handle(drive);
96                         return ide_stopped;
97                 }
98                 /* Command finished - Call the callback function */
99                 pc->callback(drive);
100                 return ide_stopped;
101         }
102
103         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
104                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
105                 printk(KERN_ERR "%s: The device wants to issue more interrupts "
106                                 "in DMA mode\n", drive->name);
107                 ide_dma_off(drive);
108                 return ide_do_reset(drive);
109         }
110
111         /* Get the number of bytes to transfer on this interrupt. */
112         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
113
114         if (ireason & CD) {
115                 printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
116                 return ide_do_reset(drive);
117         }
118         if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
119                 /* Hopefully, we will never get here */
120                 printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
121                                 "to %s!\n", drive->name,
122                                 (ireason & IO) ? "Write" : "Read",
123                                 (ireason & IO) ? "Read" : "Write");
124                 return ide_do_reset(drive);
125         }
126         if (!(pc->flags & PC_FLAG_WRITING)) {
127                 /* Reading - Check that we have enough space */
128                 temp = pc->xferred + bcount;
129                 if (temp > pc->req_xfer) {
130                         if (temp > pc->buf_size) {
131                                 printk(KERN_ERR "%s: The device wants to send "
132                                                 "us more data than expected - "
133                                                 "discarding data\n",
134                                                 drive->name);
135                                 if (scsi)
136                                         temp = pc->buf_size - pc->xferred;
137                                 else
138                                         temp = 0;
139                                 if (temp) {
140                                         if (pc->sg)
141                                                 io_buffers(drive, pc, temp, 0);
142                                         else
143                                                 hwif->input_data(drive, NULL,
144                                                         pc->cur_pos, temp);
145                                         printk(KERN_ERR "%s: transferred %d of "
146                                                         "%d bytes\n",
147                                                         drive->name,
148                                                         temp, bcount);
149                                 }
150                                 pc->xferred += temp;
151                                 pc->cur_pos += temp;
152                                 ide_pad_transfer(drive, 0, bcount - temp);
153                                 ide_set_handler(drive, handler, timeout,
154                                                 expiry);
155                                 return ide_started;
156                         }
157                         debug_log("The device wants to send us more data than "
158                                   "expected - allowing transfer\n");
159                 }
160                 xferfunc = hwif->input_data;
161         } else
162                 xferfunc = hwif->output_data;
163
164         if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
165             (drive->media == ide_tape && !scsi && pc->bh) ||
166             (scsi && pc->sg))
167                 io_buffers(drive, pc, bcount, !!(pc->flags & PC_FLAG_WRITING));
168         else
169                 xferfunc(drive, NULL, pc->cur_pos, bcount);
170
171         /* Update the current position */
172         pc->xferred += bcount;
173         pc->cur_pos += bcount;
174
175         debug_log("[cmd %x] transferred %d bytes on that intr.\n",
176                   pc->c[0], bcount);
177
178         /* And set the interrupt handler again */
179         ide_set_handler(drive, handler, timeout, expiry);
180         return ide_started;
181 }
182 EXPORT_SYMBOL_GPL(ide_pc_intr);
183
184 static u8 ide_read_ireason(ide_drive_t *drive)
185 {
186         ide_task_t task;
187
188         memset(&task, 0, sizeof(task));
189         task.tf_flags = IDE_TFLAG_IN_NSECT;
190
191         drive->hwif->tf_read(drive, &task);
192
193         return task.tf.nsect & 3;
194 }
195
196 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
197 {
198         int retries = 100;
199
200         while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
201                 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
202                                 "a packet command, retrying\n", drive->name);
203                 udelay(100);
204                 ireason = ide_read_ireason(drive);
205                 if (retries == 0) {
206                         printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
207                                         "a packet command, ignoring\n",
208                                         drive->name);
209                         ireason |= CD;
210                         ireason &= ~IO;
211                 }
212         }
213
214         return ireason;
215 }
216
217 ide_startstop_t ide_transfer_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
218                                 ide_handler_t *handler, unsigned int timeout,
219                                 ide_expiry_t *expiry)
220 {
221         ide_hwif_t *hwif = drive->hwif;
222         ide_startstop_t startstop;
223         u8 ireason;
224
225         if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) {
226                 printk(KERN_ERR "%s: Strange, packet command initiated yet "
227                                 "DRQ isn't asserted\n", drive->name);
228                 return startstop;
229         }
230
231         ireason = ide_read_ireason(drive);
232         if (drive->media == ide_tape && !drive->scsi)
233                 ireason = ide_wait_ireason(drive, ireason);
234
235         if ((ireason & CD) == 0 || (ireason & IO)) {
236                 printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
237                                 "a packet command\n", drive->name);
238                 return ide_do_reset(drive);
239         }
240
241         /* Set the interrupt routine */
242         ide_set_handler(drive, handler, timeout, expiry);
243
244         /* Begin DMA, if necessary */
245         if (pc->flags & PC_FLAG_DMA_OK) {
246                 pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
247                 hwif->dma_ops->dma_start(drive);
248         }
249
250         /* Send the actual packet */
251         if ((pc->flags & PC_FLAG_ZIP_DRIVE) == 0)
252                 hwif->output_data(drive, NULL, pc->c, 12);
253
254         return ide_started;
255 }
256 EXPORT_SYMBOL_GPL(ide_transfer_pc);
257
258 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
259                              ide_handler_t *handler, unsigned int timeout,
260                              ide_expiry_t *expiry)
261 {
262         ide_hwif_t *hwif = drive->hwif;
263         u16 bcount;
264         u8 dma = 0;
265
266         /* We haven't transferred any data yet */
267         pc->xferred = 0;
268         pc->cur_pos = pc->buf;
269
270         /* Request to transfer the entire buffer at once */
271         if (drive->media == ide_tape && !drive->scsi)
272                 bcount = pc->req_xfer;
273         else
274                 bcount = min(pc->req_xfer, 63 * 1024);
275
276         if (pc->flags & PC_FLAG_DMA_ERROR) {
277                 pc->flags &= ~PC_FLAG_DMA_ERROR;
278                 ide_dma_off(drive);
279         }
280
281         if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
282                 if (drive->scsi)
283                         hwif->sg_mapped = 1;
284                 dma = !hwif->dma_ops->dma_setup(drive);
285                 if (drive->scsi)
286                         hwif->sg_mapped = 0;
287         }
288
289         if (!dma)
290                 pc->flags &= ~PC_FLAG_DMA_OK;
291
292         ide_pktcmd_tf_load(drive, drive->scsi ? 0 : IDE_TFLAG_OUT_DEVICE,
293                            bcount, dma);
294
295         /* Issue the packet command */
296         if (pc->flags & PC_FLAG_DRQ_INTERRUPT) {
297                 ide_execute_command(drive, WIN_PACKETCMD, handler,
298                                     timeout, NULL);
299                 return ide_started;
300         } else {
301                 ide_execute_pkt_cmd(drive);
302                 return (*handler)(drive);
303         }
304 }
305 EXPORT_SYMBOL_GPL(ide_issue_pc);