drivers/ata/pata_sl82c105.c

   1 /*
   2  * pata_sl82c105.c      - SL82C105 PATA for new ATA layer
   3  *                        (C) 2005 Red Hat Inc
   4  *
   5  * Based in part on linux/drivers/ide/pci/sl82c105.c
   6  *              SL82C105/Winbond 553 IDE driver
   7  *
   8  * and in part on the documentation and errata sheet
   9  *
  10  *
  11  * Note: The controller like many controllers has shared timings for
  12  * PIO and DMA. We thus flip to the DMA timings in dma_start and flip back
  13  * in the dma_stop function. Thus we actually don't need a set_dmamode
  14  * method as the PIO method is always called and will set the right PIO
  15  * timing parameters.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/pci.h>
  21 #include <linux/init.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/delay.h>
  24 #include <scsi/scsi_host.h>
  25 #include <linux/libata.h>
  26
  27 #define DRV_NAME "pata_sl82c105"
  28 #define DRV_VERSION "0.3.3"
  29
  30 enum {
  31         /*
  32          * SL82C105 PCI config register 0x40 bits.
  33          */
  34         CTRL_IDE_IRQB   =       (1 << 30),
  35         CTRL_IDE_IRQA   =       (1 << 28),
  36         CTRL_LEGIRQ     =       (1 << 11),
  37         CTRL_P1F16      =       (1 << 5),
  38         CTRL_P1EN       =       (1 << 4),
  39         CTRL_P0F16      =       (1 << 1),
  40         CTRL_P0EN       =       (1 << 0)
  41 };
  42
  43 /**
  44  *      sl82c105_pre_reset              -       probe begin
  45  *      @link: ATA link
  46  *      @deadline: deadline jiffies for the operation
  47  *
  48  *      Set up cable type and use generic probe init
  49  */
  50
  51 static int sl82c105_pre_reset(struct ata_link *link, unsigned long deadline)
  52 {
  53         static const struct pci_bits sl82c105_enable_bits[] = {
  54                 { 0x40, 1, 0x01, 0x01 },
  55                 { 0x40, 1, 0x10, 0x10 }
  56         };
  57         struct ata_port *ap = link->ap;
  58         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  59
  60         if (ap->port_no && !pci_test_config_bits(pdev, &sl82c105_enable_bits[ap->port_no]))
  61                 return -ENOENT;
  62         return ata_sff_prereset(link, deadline);
  63 }
  64
  65
  66 /**
  67  *      sl82c105_configure_piomode      -       set chip PIO timing
  68  *      @ap: ATA interface
  69  *      @adev: ATA device
  70  *      @pio: PIO mode
  71  *
  72  *      Called to do the PIO mode setup. Our timing registers are shared
  73  *      so a configure_dmamode call will undo any work we do here and vice
  74  *      versa
  75  */
  76
  77 static void sl82c105_configure_piomode(struct ata_port *ap, struct ata_device *adev, int pio)
  78 {
  79         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
  80         static u16 pio_timing[5] = {
  81                 0x50D, 0x407, 0x304, 0x242, 0x240
  82         };
  83         u16 dummy;
  84         int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
  85
  86         pci_write_config_word(pdev, timing, pio_timing[pio]);
  87         /* Can we lose this oddity of the old driver */
  88         pci_read_config_word(pdev, timing, &dummy);
  89 }
  90
  91 /**
  92  *      sl82c105_set_piomode    -       set initial PIO mode data
  93  *      @ap: ATA interface
  94  *      @adev: ATA device
  95  *
  96  *      Called to do the PIO mode setup. Our timing registers are shared
  97  *      but we want to set the PIO timing by default.
  98  */
  99
 100 static void sl82c105_set_piomode(struct ata_port *ap, struct ata_device *adev)
 101 {
 102         sl82c105_configure_piomode(ap, adev, adev->pio_mode - XFER_PIO_0);
 103 }
 104
 105 /**
 106  *      sl82c105_configure_dmamode      -       set DMA mode in chip
 107  *      @ap: ATA interface
 108  *      @adev: ATA device
 109  *
 110  *      Load DMA cycle times into the chip ready for a DMA transfer
 111  *      to occur.
 112  */
 113
 114 static void sl82c105_configure_dmamode(struct ata_port *ap, struct ata_device *adev)
 115 {
 116         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 117         static u16 dma_timing[3] = {
 118                 0x707, 0x201, 0x200
 119         };
 120         u16 dummy;
 121         int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
 122         int dma = adev->dma_mode - XFER_MW_DMA_0;
 123
 124         pci_write_config_word(pdev, timing, dma_timing[dma]);
 125         /* Can we lose this oddity of the old driver */
 126         pci_read_config_word(pdev, timing, &dummy);
 127 }
 128
 129 /**
 130  *      sl82c105_reset_engine   -       Reset the DMA engine
 131  *      @ap: ATA interface
 132  *
 133  *      The sl82c105 has some serious problems with the DMA engine
 134  *      when transfers don't run as expected or ATAPI is used. The
 135  *      recommended fix is to reset the engine each use using a chip
 136  *      test register.
 137  */
 138
 139 static void sl82c105_reset_engine(struct ata_port *ap)
 140 {
 141         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 142         u16 val;
 143
 144         pci_read_config_word(pdev, 0x7E, &val);
 145         pci_write_config_word(pdev, 0x7E, val | 4);
 146         pci_write_config_word(pdev, 0x7E, val & ~4);
 147 }
 148
 149 /**
 150  *      sl82c105_bmdma_start            -       DMA engine begin
 151  *      @qc: ATA command
 152  *
 153  *      Reset the DMA engine each use as recommended by the errata
 154  *      document.
 155  *
 156  *      FIXME: if we switch clock at BMDMA start/end we might get better
 157  *      PIO performance on DMA capable devices.
 158  */
 159
 160 static void sl82c105_bmdma_start(struct ata_queued_cmd *qc)
 161 {
 162         struct ata_port *ap = qc->ap;
 163
 164         udelay(100);
 165         sl82c105_reset_engine(ap);
 166         udelay(100);
 167
 168         /* Set the clocks for DMA */
 169         sl82c105_configure_dmamode(ap, qc->dev);
 170         /* Activate DMA */
 171         ata_bmdma_start(qc);
 172 }
 173
 174 /**
 175  *      sl82c105_bmdma_end              -       DMA engine stop
 176  *      @qc: ATA command
 177  *
 178  *      Reset the DMA engine each use as recommended by the errata
 179  *      document.
 180  *
 181  *      This function is also called to turn off DMA when a timeout occurs
 182  *      during DMA operation. In both cases we need to reset the engine,
 183  *      so no actual eng_timeout handler is required.
 184  *
 185  *      We assume bmdma_stop is always called if bmdma_start as called. If
 186  *      not then we may need to wrap qc_issue.
 187  */
 188
 189 static void sl82c105_bmdma_stop(struct ata_queued_cmd *qc)
 190 {
 191         struct ata_port *ap = qc->ap;
 192
 193         ata_bmdma_stop(qc);
 194         sl82c105_reset_engine(ap);
 195         udelay(100);
 196
 197         /* This will redo the initial setup of the DMA device to matching
 198            PIO timings */
 199         sl82c105_set_piomode(ap, qc->dev);
 200 }
 201
 202 /**
 203  *      sl82c105_qc_defer       -       implement serialization
 204  *      @qc: command
 205  *
 206  *      We must issue one command per host not per channel because
 207  *      of the reset bug.
 208  *
 209  *      Q: is the scsi host lock sufficient ?
 210  */
 211
 212 static int sl82c105_qc_defer(struct ata_queued_cmd *qc)
 213 {
 214         struct ata_host *host = qc->ap->host;
 215         struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
 216         int rc;
 217
 218         /* First apply the usual rules */
 219         rc = ata_std_qc_defer(qc);
 220         if (rc != 0)
 221                 return rc;
 222
 223         /* Now apply serialization rules. Only allow a command if the
 224            other channel state machine is idle */
 225         if (alt && alt->qc_active)
 226                 return  ATA_DEFER_PORT;
 227         return 0;
 228 }
 229
 230 static struct scsi_host_template sl82c105_sht = {
 231         ATA_BMDMA_SHT(DRV_NAME),
 232 };
 233
 234 static struct ata_port_operations sl82c105_port_ops = {
 235         .inherits       = &ata_bmdma_port_ops,
 236         .qc_defer       = sl82c105_qc_defer,
 237         .bmdma_start    = sl82c105_bmdma_start,
 238         .bmdma_stop     = sl82c105_bmdma_stop,
 239         .cable_detect   = ata_cable_40wire,
 240         .set_piomode    = sl82c105_set_piomode,
 241         .prereset       = sl82c105_pre_reset,
 242 };
 243
 244 /**
 245  *      sl82c105_bridge_revision        -       find bridge version
 246  *      @pdev: PCI device for the ATA function
 247  *
 248  *      Locates the PCI bridge associated with the ATA function and
 249  *      providing it is a Winbond 553 reports the revision. If it cannot
 250  *      find a revision or the right device it returns -1
 251  */
 252
 253 static int sl82c105_bridge_revision(struct pci_dev *pdev)
 254 {
 255         struct pci_dev *bridge;
 256
 257         /*
 258          * The bridge should be part of the same device, but function 0.
 259          */
 260         bridge = pci_get_slot(pdev->bus,
 261                                PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
 262         if (!bridge)
 263                 return -1;
 264
 265         /*
 266          * Make sure it is a Winbond 553 and is an ISA bridge.
 267          */
 268         if (bridge->vendor != PCI_VENDOR_ID_WINBOND ||
 269             bridge->device != PCI_DEVICE_ID_WINBOND_83C553 ||
 270             bridge->class >> 8 != PCI_CLASS_BRIDGE_ISA) {
 271                 pci_dev_put(bridge);
 272                 return -1;
 273         }
 274         /*
 275          * We need to find function 0's revision, not function 1
 276          */
 277         pci_dev_put(bridge);
 278         return bridge->revision;
 279 }
 280
 281
 282 static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id)
 283 {
 284         static const struct ata_port_info info_dma = {
 285                 .flags = ATA_FLAG_SLAVE_POSS,
 286                 .pio_mask = ATA_PIO4,
 287                 .mwdma_mask = ATA_MWDMA2,
 288                 .port_ops = &sl82c105_port_ops
 289         };
 290         static const struct ata_port_info info_early = {
 291                 .flags = ATA_FLAG_SLAVE_POSS,
 292                 .pio_mask = ATA_PIO4,
 293                 .port_ops = &sl82c105_port_ops
 294         };
 295         /* for now use only the first port */
 296         const struct ata_port_info *ppi[] = { &info_early,
 297                                                NULL };
 298         u32 val;
 299         int rev;
 300         int rc;
 301
 302         rc = pcim_enable_device(dev);
 303         if (rc)
 304                 return rc;
 305
 306         rev = sl82c105_bridge_revision(dev);
 307
 308         if (rev == -1)
 309                 dev_printk(KERN_WARNING, &dev->dev, "pata_sl82c105: Unable to find bridge, disabling DMA.\n");
 310         else if (rev <= 5)
 311                 dev_printk(KERN_WARNING, &dev->dev, "pata_sl82c105: Early bridge revision, no DMA available.\n");
 312         else
 313                 ppi[0] = &info_dma;
 314
 315         pci_read_config_dword(dev, 0x40, &val);
 316         val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
 317         pci_write_config_dword(dev, 0x40, val);
 318
 319         return ata_pci_sff_init_one(dev, ppi, &sl82c105_sht, NULL);
 320 }
 321
 322 static const struct pci_device_id sl82c105[] = {
 323         { PCI_VDEVICE(WINBOND, PCI_DEVICE_ID_WINBOND_82C105), },
 324
 325         { },
 326 };
 327
 328 static struct pci_driver sl82c105_pci_driver = {
 329         .name           = DRV_NAME,
 330         .id_table       = sl82c105,
 331         .probe          = sl82c105_init_one,
 332         .remove         = ata_pci_remove_one
 333 };
 334
 335 static int __init sl82c105_init(void)
 336 {
 337         return pci_register_driver(&sl82c105_pci_driver);
 338 }
 339
 340 static void __exit sl82c105_exit(void)
 341 {
 342         pci_unregister_driver(&sl82c105_pci_driver);
 343 }
 344
 345 MODULE_AUTHOR("Alan Cox");
 346 MODULE_DESCRIPTION("low-level driver for Sl82c105");
 347 MODULE_LICENSE("GPL");
 348 MODULE_DEVICE_TABLE(pci, sl82c105);
 349 MODULE_VERSION(DRV_VERSION);
 350
 351 module_init(sl82c105_init);
 352 module_exit(sl82c105_exit);