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