drivers/ide/ide-xfer-mode.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/types.h>
   3 #include <linux/string.h>
   4 #include <linux/kernel.h>
   5 #include <linux/export.h>
   6 #include <linux/interrupt.h>
   7 #include <linux/ide.h>
   8 #include <linux/bitops.h>
   9
  10 static const char *udma_str[] =
  11          { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
  12            "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
  13 static const char *mwdma_str[] =
  14         { "MWDMA0", "MWDMA1", "MWDMA2", "MWDMA3", "MWDMA4" };
  15 static const char *swdma_str[] =
  16         { "SWDMA0", "SWDMA1", "SWDMA2" };
  17 static const char *pio_str[] =
  18         { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5", "PIO6" };
  19
  20 /**
  21  *      ide_xfer_verbose        -       return IDE mode names
  22  *      @mode: transfer mode
  23  *
  24  *      Returns a constant string giving the name of the mode
  25  *      requested.
  26  */
  27
  28 const char *ide_xfer_verbose(u8 mode)
  29 {
  30         const char *s;
  31         u8 i = mode & 0xf;
  32
  33         if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
  34                 s = udma_str[i];
  35         else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_4)
  36                 s = mwdma_str[i];
  37         else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
  38                 s = swdma_str[i];
  39         else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_6)
  40                 s = pio_str[i & 0x7];
  41         else if (mode == XFER_PIO_SLOW)
  42                 s = "PIO SLOW";
  43         else
  44                 s = "XFER ERROR";
  45
  46         return s;
  47 }
  48 EXPORT_SYMBOL(ide_xfer_verbose);
  49
  50 /**
  51  *      ide_get_best_pio_mode   -       get PIO mode from drive
  52  *      @drive: drive to consider
  53  *      @mode_wanted: preferred mode
  54  *      @max_mode: highest allowed mode
  55  *
  56  *      This routine returns the recommended PIO settings for a given drive,
  57  *      based on the drive->id information and the ide_pio_blacklist[].
  58  *
  59  *      Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
  60  *      This is used by most chipset support modules when "auto-tuning".
  61  */
  62
  63 static u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
  64 {
  65         u16 *id = drive->id;
  66         int pio_mode = -1, overridden = 0;
  67
  68         if (mode_wanted != 255)
  69                 return min_t(u8, mode_wanted, max_mode);
  70
  71         if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0)
  72                 pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]);
  73
  74         if (pio_mode != -1) {
  75                 printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
  76         } else {
  77                 pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8;
  78                 if (pio_mode > 2) {     /* 2 is maximum allowed tPIO value */
  79                         pio_mode = 2;
  80                         overridden = 1;
  81                 }
  82
  83                 if (id[ATA_ID_FIELD_VALID] & 2) {             /* ATA2? */
  84                         if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 7))
  85                                 pio_mode = 4 + min_t(int, 2,
  86                                                      id[ATA_ID_CFA_MODES] & 7);
  87                         else if (ata_id_has_iordy(id)) {
  88                                 if (id[ATA_ID_PIO_MODES] & 7) {
  89                                         overridden = 0;
  90                                         if (id[ATA_ID_PIO_MODES] & 4)
  91                                                 pio_mode = 5;
  92                                         else if (id[ATA_ID_PIO_MODES] & 2)
  93                                                 pio_mode = 4;
  94                                         else
  95                                                 pio_mode = 3;
  96                                 }
  97                         }
  98                 }
  99
 100                 if (overridden)
 101                         printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
 102                                          drive->name);
 103         }
 104
 105         if (pio_mode > max_mode)
 106                 pio_mode = max_mode;
 107
 108         return pio_mode;
 109 }
 110
 111 int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
 112 {
 113         /*
 114          * IORDY may lead to controller lock up on certain controllers
 115          * if the port is not occupied.
 116          */
 117         if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
 118                 return 0;
 119         return ata_id_pio_need_iordy(drive->id, pio);
 120 }
 121 EXPORT_SYMBOL_GPL(ide_pio_need_iordy);
 122
 123 int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
 124 {
 125         ide_hwif_t *hwif = drive->hwif;
 126         const struct ide_port_ops *port_ops = hwif->port_ops;
 127
 128         if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
 129                 return 0;
 130
 131         if (port_ops == NULL || port_ops->set_pio_mode == NULL)
 132                 return -1;
 133
 134         /*
 135          * TODO: temporary hack for some legacy host drivers that didn't
 136          * set transfer mode on the device in ->set_pio_mode method...
 137          */
 138         if (port_ops->set_dma_mode == NULL) {
 139                 drive->pio_mode = mode;
 140                 port_ops->set_pio_mode(hwif, drive);
 141                 return 0;
 142         }
 143
 144         if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
 145                 if (ide_config_drive_speed(drive, mode))
 146                         return -1;
 147                 drive->pio_mode = mode;
 148                 port_ops->set_pio_mode(hwif, drive);
 149                 return 0;
 150         } else {
 151                 drive->pio_mode = mode;
 152                 port_ops->set_pio_mode(hwif, drive);
 153                 return ide_config_drive_speed(drive, mode);
 154         }
 155 }
 156
 157 int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
 158 {
 159         ide_hwif_t *hwif = drive->hwif;
 160         const struct ide_port_ops *port_ops = hwif->port_ops;
 161
 162         if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
 163                 return 0;
 164
 165         if (port_ops == NULL || port_ops->set_dma_mode == NULL)
 166                 return -1;
 167
 168         if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
 169                 if (ide_config_drive_speed(drive, mode))
 170                         return -1;
 171                 drive->dma_mode = mode;
 172                 port_ops->set_dma_mode(hwif, drive);
 173                 return 0;
 174         } else {
 175                 drive->dma_mode = mode;
 176                 port_ops->set_dma_mode(hwif, drive);
 177                 return ide_config_drive_speed(drive, mode);
 178         }
 179 }
 180 EXPORT_SYMBOL_GPL(ide_set_dma_mode);
 181
 182 /* req_pio == "255" for auto-tune */
 183 void ide_set_pio(ide_drive_t *drive, u8 req_pio)
 184 {
 185         ide_hwif_t *hwif = drive->hwif;
 186         const struct ide_port_ops *port_ops = hwif->port_ops;
 187         u8 host_pio, pio;
 188
 189         if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
 190             (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
 191                 return;
 192
 193         BUG_ON(hwif->pio_mask == 0x00);
 194
 195         host_pio = fls(hwif->pio_mask) - 1;
 196
 197         pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
 198
 199         /*
 200          * TODO:
 201          * - report device max PIO mode
 202          * - check req_pio != 255 against device max PIO mode
 203          */
 204         printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
 205                           drive->name, host_pio, req_pio,
 206                           req_pio == 255 ? "(auto-tune)" : "", pio);
 207
 208         (void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
 209 }
 210 EXPORT_SYMBOL_GPL(ide_set_pio);
 211
 212 /**
 213  *      ide_rate_filter         -       filter transfer mode
 214  *      @drive: IDE device
 215  *      @speed: desired speed
 216  *
 217  *      Given the available transfer modes this function returns
 218  *      the best available speed at or below the speed requested.
 219  *
 220  *      TODO: check device PIO capabilities
 221  */
 222
 223 static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
 224 {
 225         ide_hwif_t *hwif = drive->hwif;
 226         u8 mode = ide_find_dma_mode(drive, speed);
 227
 228         if (mode == 0) {
 229                 if (hwif->pio_mask)
 230                         mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
 231                 else
 232                         mode = XFER_PIO_4;
 233         }
 234
 235 /*      printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */
 236
 237         return min(speed, mode);
 238 }
 239
 240 /**
 241  *      ide_set_xfer_rate       -       set transfer rate
 242  *      @drive: drive to set
 243  *      @rate: speed to attempt to set
 244  *
 245  *      General helper for setting the speed of an IDE device. This
 246  *      function knows about user enforced limits from the configuration
 247  *      which ->set_pio_mode/->set_dma_mode does not.
 248  */
 249
 250 int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
 251 {
 252         ide_hwif_t *hwif = drive->hwif;
 253         const struct ide_port_ops *port_ops = hwif->port_ops;
 254
 255         if (port_ops == NULL || port_ops->set_dma_mode == NULL ||
 256             (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
 257                 return -1;
 258
 259         rate = ide_rate_filter(drive, rate);
 260
 261         BUG_ON(rate < XFER_PIO_0);
 262
 263         if (rate >= XFER_PIO_0 && rate <= XFER_PIO_6)
 264                 return ide_set_pio_mode(drive, rate);
 265
 266         return ide_set_dma_mode(drive, rate);
 267 }