drivers/ata/pata_at91.c

   1 /*
   2  * PATA driver for AT91SAM9260 Static Memory Controller
   3  * with CompactFlash interface in True IDE mode
   4  *
   5  * Copyright (C) 2009 Matyukevich Sergey
   6  *               2011 Igor Plyatov
   7  *
   8  * Based on:
   9  *      * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
  10  *      * pata_at32 driver by Kristoffer Nyborg Gregertsen
  11  *      * at91_ide driver by Stanislaw Gruszka
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License version 2
  15  * as published by the Free Software Foundation.
  16  *
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/gfp.h>
  24 #include <scsi/scsi_host.h>
  25 #include <linux/ata.h>
  26 #include <linux/clk.h>
  27 #include <linux/libata.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/ata_platform.h>
  30
  31 #include <mach/at91sam9_smc.h>
  32 #include <mach/board.h>
  33 #include <asm/gpio.h>
  34
  35 #define DRV_NAME                "pata_at91"
  36 #define DRV_VERSION             "0.3"
  37
  38 #define CF_IDE_OFFSET           0x00c00000
  39 #define CF_ALT_IDE_OFFSET       0x00e00000
  40 #define CF_IDE_RES_SIZE         0x08
  41 #define CS_PULSE_MAXIMUM        319
  42 #define ER_SMC_CALC             1
  43 #define ER_SMC_RECALC           2
  44
  45 struct at91_ide_info {
  46         unsigned long mode;
  47         unsigned int cs;
  48         struct clk *mck;
  49         void __iomem *ide_addr;
  50         void __iomem *alt_addr;
  51 };
  52
  53 /**
  54  * struct smc_range - range of valid values for SMC register.
  55  */
  56 struct smc_range {
  57         int min;
  58         int max;
  59 };
  60
  61 /**
  62  * adjust_smc_value - adjust value for one of SMC registers.
  63  * @value: adjusted value
  64  * @range: array of SMC ranges with valid values
  65  * @size: SMC ranges array size
  66  *
  67  * This returns the difference between input and output value or negative
  68  * in case of invalid input value.
  69  * If negative returned, then output value = maximal possible from ranges.
  70  */
  71 static int adjust_smc_value(int *value, struct smc_range *range, int size)
  72 {
  73         int maximum = (range + size - 1)->max;
  74         int remainder;
  75
  76         do {
  77                 if (*value < range->min) {
  78                         remainder = range->min - *value;
  79                         *value = range->min; /* nearest valid value */
  80                         return remainder;
  81                 } else if ((range->min <= *value) && (*value <= range->max))
  82                         return 0;
  83
  84                 range++;
  85         } while (--size);
  86         *value = maximum;
  87
  88         return -1; /* invalid value */
  89 }
  90
  91 /**
  92  * calc_smc_vals - calculate SMC register values
  93  * @dev: ATA device
  94  * @setup: SMC_SETUP register value
  95  * @pulse: SMC_PULSE register value
  96  * @cycle: SMC_CYCLE register value
  97  *
  98  * This returns negative in case of invalid values for SMC registers:
  99  * -ER_SMC_RECALC - recalculation required for SMC values,
 100  * -ER_SMC_CALC - calculation failed (invalid input values).
 101  *
 102  * SMC use special coding scheme, see "Coding and Range of Timing
 103  * Parameters" table from AT91SAM9 datasheets.
 104  *
 105  *      SMC_SETUP = 128*setup[5] + setup[4:0]
 106  *      SMC_PULSE = 256*pulse[6] + pulse[5:0]
 107  *      SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
 108  */
 109 static int calc_smc_vals(struct device *dev,
 110                 int *setup, int *pulse, int *cycle, int *cs_pulse)
 111 {
 112         int ret_val;
 113         int err = 0;
 114         struct smc_range range_setup[] = {      /* SMC_SETUP valid values */
 115                 {.min = 0,      .max = 31},     /* first  range */
 116                 {.min = 128,    .max = 159}     /* second range */
 117         };
 118         struct smc_range range_pulse[] = {      /* SMC_PULSE valid values */
 119                 {.min = 0,      .max = 63},     /* first  range */
 120                 {.min = 256,    .max = 319}     /* second range */
 121         };
 122         struct smc_range range_cycle[] = {      /* SMC_CYCLE valid values */
 123                 {.min = 0,      .max = 127},    /* first  range */
 124                 {.min = 256,    .max = 383},    /* second range */
 125                 {.min = 512,    .max = 639},    /* third  range */
 126                 {.min = 768,    .max = 895}     /* fourth range */
 127         };
 128
 129         ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
 130         if (ret_val < 0)
 131                 dev_warn(dev, "maximal SMC Setup value\n");
 132         else
 133                 *cycle += ret_val;
 134
 135         ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
 136         if (ret_val < 0)
 137                 dev_warn(dev, "maximal SMC Pulse value\n");
 138         else
 139                 *cycle += ret_val;
 140
 141         ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
 142         if (ret_val < 0)
 143                 dev_warn(dev, "maximal SMC Cycle value\n");
 144
 145         *cs_pulse = *cycle;
 146         if (*cs_pulse > CS_PULSE_MAXIMUM) {
 147                 dev_err(dev, "unable to calculate valid SMC settings\n");
 148                 return -ER_SMC_CALC;
 149         }
 150
 151         ret_val = adjust_smc_value(cs_pulse, range_pulse,
 152                                         ARRAY_SIZE(range_pulse));
 153         if (ret_val < 0) {
 154                 dev_warn(dev, "maximal SMC CS Pulse value\n");
 155         } else if (ret_val != 0) {
 156                 *cycle = *cs_pulse;
 157                 dev_warn(dev, "SMC Cycle extended\n");
 158                 err = -ER_SMC_RECALC;
 159         }
 160
 161         return err;
 162 }
 163
 164 /**
 165  * to_smc_format - convert values into SMC format
 166  * @setup: SETUP value of SMC Setup Register
 167  * @pulse: PULSE value of SMC Pulse Register
 168  * @cycle: CYCLE value of SMC Cycle Register
 169  * @cs_pulse: NCS_PULSE value of SMC Pulse Register
 170  */
 171 static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
 172 {
 173         *setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
 174         *pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
 175         *cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
 176         *cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
 177 }
 178
 179 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
 180 {
 181         unsigned long mul;
 182
 183         /*
 184         * cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
 185         *     x * (f / 1_000_000_000) =
 186         *     x * ((f * 65536) / 1_000_000_000) / 65536 =
 187         *     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
 188         */
 189
 190         mul = (mck_hz / 10000) << 16;
 191         mul /= 100000;
 192
 193         return (ns * mul + 65536) >> 16;    /* rounding */
 194 }
 195
 196 /**
 197  * set_smc_timing - SMC timings setup.
 198  * @dev: device
 199  * @info: AT91 IDE info
 200  * @ata: ATA timings
 201  *
 202  * Its assumed that write timings are same as read timings,
 203  * cs_setup = 0 and cs_pulse = cycle.
 204  */
 205 static void set_smc_timing(struct device *dev, struct ata_device *adev,
 206                 struct at91_ide_info *info, const struct ata_timing *ata)
 207 {
 208         int ret = 0;
 209         int use_iordy;
 210         unsigned int t6z;         /* data tristate time in ns */
 211         unsigned int cycle;       /* SMC Cycle width in MCK ticks */
 212         unsigned int setup;       /* SMC Setup width in MCK ticks */
 213         unsigned int pulse;       /* CFIOR and CFIOW pulse width in MCK ticks */
 214         unsigned int cs_setup = 0;/* CS4 or CS5 setup width in MCK ticks */
 215         unsigned int cs_pulse;    /* CS4 or CS5 pulse width in MCK ticks*/
 216         unsigned int tdf_cycles;  /* SMC TDF MCK ticks */
 217         unsigned long mck_hz;     /* MCK frequency in Hz */
 218
 219         t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
 220         mck_hz = clk_get_rate(info->mck);
 221         cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
 222         setup = calc_mck_cycles(ata->setup, mck_hz);
 223         pulse = calc_mck_cycles(ata->act8b, mck_hz);
 224         tdf_cycles = calc_mck_cycles(t6z, mck_hz);
 225
 226         do {
 227                 ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
 228         } while (ret == -ER_SMC_RECALC);
 229
 230         if (ret == -ER_SMC_CALC)
 231                 dev_err(dev, "Interface may not operate correctly\n");
 232
 233         dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
 234                 setup, pulse, cycle, cs_pulse);
 235         to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
 236         /* disable or enable waiting for IORDY signal */
 237         use_iordy = ata_pio_need_iordy(adev);
 238         if (use_iordy)
 239                 info->mode |= AT91_SMC_EXNWMODE_READY;
 240
 241         if (tdf_cycles > 15) {
 242                 tdf_cycles = 15;
 243                 dev_warn(dev, "maximal SMC TDF Cycles value\n");
 244         }
 245
 246         dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);
 247         info->mode |= AT91_SMC_TDF_(tdf_cycles);
 248
 249         /* write SMC Setup Register */
 250         at91_sys_write(AT91_SMC_SETUP(info->cs),
 251                         AT91_SMC_NWESETUP_(setup) |
 252                         AT91_SMC_NRDSETUP_(setup) |
 253                         AT91_SMC_NCS_WRSETUP_(cs_setup) |
 254                         AT91_SMC_NCS_RDSETUP_(cs_setup));
 255         /* write SMC Pulse Register */
 256         at91_sys_write(AT91_SMC_PULSE(info->cs),
 257                         AT91_SMC_NWEPULSE_(pulse) |
 258                         AT91_SMC_NRDPULSE_(pulse) |
 259                         AT91_SMC_NCS_WRPULSE_(cs_pulse) |
 260                         AT91_SMC_NCS_RDPULSE_(cs_pulse));
 261         /* write SMC Cycle Register */
 262         at91_sys_write(AT91_SMC_CYCLE(info->cs),
 263                         AT91_SMC_NWECYCLE_(cycle) |
 264                         AT91_SMC_NRDCYCLE_(cycle));
 265         /* write SMC Mode Register*/
 266         at91_sys_write(AT91_SMC_MODE(info->cs), info->mode);
 267 }
 268
 269 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 270 {
 271         struct at91_ide_info *info = ap->host->private_data;
 272         struct ata_timing timing;
 273         int ret;
 274
 275         /* Compute ATA timing and set it to SMC */
 276         ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 277         if (ret) {
 278                 dev_warn(ap->dev, "Failed to compute ATA timing %d, "
 279                          "set PIO_0 timing\n", ret);
 280                 timing = *ata_timing_find_mode(XFER_PIO_0);
 281         }
 282         set_smc_timing(ap->dev, adev, info, &timing);
 283 }
 284
 285 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 286                 unsigned char *buf, unsigned int buflen, int rw)
 287 {
 288         struct at91_ide_info *info = dev->link->ap->host->private_data;
 289         unsigned int consumed;
 290         unsigned long flags;
 291         unsigned int mode;
 292
 293         local_irq_save(flags);
 294         mode = at91_sys_read(AT91_SMC_MODE(info->cs));
 295
 296         /* set 16bit mode before writing data */
 297         at91_sys_write(AT91_SMC_MODE(info->cs),
 298                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16);
 299
 300         consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
 301
 302         /* restore 8bit mode after data is written */
 303         at91_sys_write(AT91_SMC_MODE(info->cs),
 304                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8);
 305
 306         local_irq_restore(flags);
 307         return consumed;
 308 }
 309
 310 static struct scsi_host_template pata_at91_sht = {
 311         ATA_PIO_SHT(DRV_NAME),
 312 };
 313
 314 static struct ata_port_operations pata_at91_port_ops = {
 315         .inherits       = &ata_sff_port_ops,
 316
 317         .sff_data_xfer  = pata_at91_data_xfer_noirq,
 318         .set_piomode    = pata_at91_set_piomode,
 319         .cable_detect   = ata_cable_40wire,
 320 };
 321
 322 static int __devinit pata_at91_probe(struct platform_device *pdev)
 323 {
 324         struct at91_cf_data *board = pdev->dev.platform_data;
 325         struct device *dev = &pdev->dev;
 326         struct at91_ide_info *info;
 327         struct resource *mem_res;
 328         struct ata_host *host;
 329         struct ata_port *ap;
 330
 331         int irq_flags = 0;
 332         int irq = 0;
 333         int ret;
 334
 335         /*  get platform resources: IO/CTL memories and irq/rst pins */
 336
 337         if (pdev->num_resources != 1) {
 338                 dev_err(&pdev->dev, "invalid number of resources\n");
 339                 return -EINVAL;
 340         }
 341
 342         mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 343
 344         if (!mem_res) {
 345                 dev_err(dev, "failed to get mem resource\n");
 346                 return -EINVAL;
 347         }
 348
 349         irq = board->irq_pin;
 350
 351         /* init ata host */
 352
 353         host = ata_host_alloc(dev, 1);
 354
 355         if (!host)
 356                 return -ENOMEM;
 357
 358         ap = host->ports[0];
 359         ap->ops = &pata_at91_port_ops;
 360         ap->flags |= ATA_FLAG_SLAVE_POSS;
 361         ap->pio_mask = ATA_PIO4;
 362
 363         if (!irq) {
 364                 ap->flags |= ATA_FLAG_PIO_POLLING;
 365                 ata_port_desc(ap, "no IRQ, using PIO polling");
 366         }
 367
 368         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 369
 370         if (!info) {
 371                 dev_err(dev, "failed to allocate memory for private data\n");
 372                 return -ENOMEM;
 373         }
 374
 375         info->mck = clk_get(NULL, "mck");
 376
 377         if (IS_ERR(info->mck)) {
 378                 dev_err(dev, "failed to get access to mck clock\n");
 379                 return -ENODEV;
 380         }
 381
 382         info->cs    = board->chipselect;
 383         info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 384                 AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 385                 AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
 386
 387         info->ide_addr = devm_ioremap(dev,
 388                         mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
 389
 390         if (!info->ide_addr) {
 391                 dev_err(dev, "failed to map IO base\n");
 392                 ret = -ENOMEM;
 393                 goto err_put;
 394         }
 395
 396         info->alt_addr = devm_ioremap(dev,
 397                         mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
 398
 399         if (!info->alt_addr) {
 400                 dev_err(dev, "failed to map CTL base\n");
 401                 ret = -ENOMEM;
 402                 goto err_put;
 403         }
 404
 405         ap->ioaddr.cmd_addr = info->ide_addr;
 406         ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 407         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 408
 409         ata_sff_std_ports(&ap->ioaddr);
 410
 411         ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 412                         (unsigned long long)mem_res->start + CF_IDE_OFFSET,
 413                         (unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
 414
 415         host->private_data = info;
 416
 417         return ata_host_activate(host, irq ? gpio_to_irq(irq) : 0,
 418                         irq ? ata_sff_interrupt : NULL,
 419                         irq_flags, &pata_at91_sht);
 420
 421 err_put:
 422         clk_put(info->mck);
 423         return ret;
 424 }
 425
 426 static int __devexit pata_at91_remove(struct platform_device *pdev)
 427 {
 428         struct ata_host *host = dev_get_drvdata(&pdev->dev);
 429         struct at91_ide_info *info;
 430
 431         if (!host)
 432                 return 0;
 433         info = host->private_data;
 434
 435         ata_host_detach(host);
 436
 437         if (!info)
 438                 return 0;
 439
 440         clk_put(info->mck);
 441
 442         return 0;
 443 }
 444
 445 static struct platform_driver pata_at91_driver = {
 446         .probe          = pata_at91_probe,
 447         .remove         = __devexit_p(pata_at91_remove),
 448         .driver         = {
 449                 .name           = DRV_NAME,
 450                 .owner          = THIS_MODULE,
 451         },
 452 };
 453
 454 static int __init pata_at91_init(void)
 455 {
 456         return platform_driver_register(&pata_at91_driver);
 457 }
 458
 459 static void __exit pata_at91_exit(void)
 460 {
 461         platform_driver_unregister(&pata_at91_driver);
 462 }
 463
 464
 465 module_init(pata_at91_init);
 466 module_exit(pata_at91_exit);
 467
 468
 469 MODULE_LICENSE("GPL");
 470 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 471 MODULE_AUTHOR("Matyukevich Sergey");
 472 MODULE_VERSION(DRV_VERSION);
 473